@article{siegler_shaughnessy_horman_vierling_king_patisaul_huhman_alexander_dudek_2024, title={Identification of hippocampal area CA2 in hamster and vole brain}, volume={532}, ISSN={["1096-9861"]}, DOI={10.1002/cne.25603}, abstractNote={AbstractPrairie voles (Microtus ochrogaster) and Syrian, or golden, hamsters (Mesocricetus auratus) are closely related to mice (Mus musculus) and are commonly used in studies of social behavior including social interaction, social memory, and aggression. Hippocampal area CA2 is known to play a key role in these behaviors in mice and responds to social stimuli in rats, but CA2 has yet to be characterized in hamsters or voles, which are also used in studies of social behaviors. Here, we used immunofluorescence to determine whether CA2 could be molecularly identified in tissue from voles and hamsters. We found that  staining for many CA2 markers was similar in these three species, with labeling seen in neurons at the distal end of the mossy fibers . In contrast, although perineuronal nets (PNNs) surround CA2 cells in mice, PNN staining differed across species. In voles, both CA2 and CA3 were labeled, whereas in hamsters, labeling was seen primarily in CA3. These results demonstrate that CA2 can be molecularly distinguished from neighboring CA1 and CA3 areas in voles and hamsters with several antibodies commonly used in mice. However, PNN staining is not useful for identifying CA2 in voles or hamsters, suggestive of differing roles for either PNNs or for the hippocampal subregions in social behavior. These findings reveal commonalities across species in the molecular profile of CA2 and should facilitate future studies of CA2 in these species.}, number={3}, journal={JOURNAL OF COMPARATIVE NEUROLOGY}, author={Siegler, Preston N. and Shaughnessy, Emma K. and Horman, Brian and Vierling, Tia T. and King, Darron H. and Patisaul, Heather B. and Huhman, Kim L. and Alexander, Georgia M. and Dudek, Serena M.}, year={2024}, month={Mar} }
 @article{schkoda_horman_witchey_armour_nelson_gaeta_scott_patisaul_2024, title={Sex-specific effects on elements of the social brain neural network in Wistar rats from perinatal exposure to FireMaster 550 or its components}, volume={105}, ISSN={["1872-9711"]}, DOI={10.1016/j.neuro.2024.09.001}, abstractNote={Developmental exposure to chemical flame retardants (FRs) has been linked to a variety of neurodevelopmental disorders and abnormal socioemotional behaviors in human and laboratory animal studies. We have previously shown in Wistar rats that gestational and lactational exposure to the FR mixture Firemaster 550 (FM 550) or its brominated or organophosphate ester (OPFR) components (at 2000 µg, 1000 µg, and 1000 µg oral to the dam respectively (absolute and not by bodyweight)) results in increased anxiety-like behaviors in females and decreased sociality in both sexes. Using their siblings, this study characterized sex and chemical specific targets of disruption in brain regions underlying each behavioral phenotype. Offspring were exposed across gestation and lactation then prepared for either immunohistochemistry or autoradiography at postnatal day 90 to quantify expression of serotonin, estrogen receptor α (ERα), and oxytocin receptor (OTR) in multiple brain regions. No effect of exposure was found in males for any biological target. In females, serotonin innervation was increased in the medial amygdala of FM 550 exposed animals while ERα expression in the bed nucleus of the stria terminalis (BNST) was reduced by FM 550 and OPFR. Evidence of disrupted OTR was observed in males, particularly the BNST but considered an exploratory finding given the small sample size. These results begin to shed light on the mechanisms by which developmental FR exposure alters socioemotional behaviors of relevance to neurodevelopmental disorders.}, journal={NEUROTOXICOLOGY}, author={Schkoda, Stacy and Horman, Brian and Witchey, Shannah and Armour, Genevieve St. and Nelson, Mason and Gaeta, Emily and Scott, Madeline and Patisaul, Heather B.}, year={2024}, month={Dec}, pages={111–120} }
 @article{elliott_patisaul_sargis_vandenberg_2024, title={Words Matter: Reflective Science Communication and Tradeoffs in Environmental Health Research}, volume={132}, ISSN={["1552-9924"]}, DOI={10.1289/EHP14527}, abstractNote={Scientists who communicate societally relevant information face challenging contexts in which misinformation, disinformation, hype, and spin are prevalent. As a result, they often face difficult decisions about how to frame their work in a socially responsible manner.}, number={10}, journal={ENVIRONMENTAL HEALTH PERSPECTIVES}, author={Elliott, Kevin C. and Patisaul, Heather B. and Sargis, Robert M. and Vandenberg, Laura N.}, year={2024}, month={Oct} }
 @article{woodruff_rayasam_axelrad_koman_chartres_bennett_birnbaum_brown_carignan_cooper_et al._2023, title={A science-based agenda for health-protective chemical assessments and decisions: overview and consensus statement}, volume={21}, ISSN={["1476-069X"]}, DOI={10.1186/s12940-022-00930-3}, abstractNote={AbstractThe manufacture and production of industrial chemicals continues to increase, with hundreds of thousands of chemicals and chemical mixtures used worldwide, leading to widespread population exposures and resultant health impacts. Low-wealth communities and communities of color often bear disproportionate burdens of exposure and impact; all compounded by regulatory delays to the detriment of public health. Multiple authoritative bodies and scientific consensus groups have called for actions to prevent harmful exposures via improved policy approaches. We worked across multiple disciplines to develop consensus recommendations for health-protective, scientific approaches to reduce harmful chemical exposures, which can be applied to current US policies governing industrial chemicals and environmental pollutants. This consensus identifies five principles and scientific recommendations for improving how agencies like the US Environmental Protection Agency (EPA) approach and conduct hazard and risk assessment and risk management analyses: (1) the financial burden of data generation for any given chemical on (or to be introduced to) the market should be on the chemical producers that benefit from their production and use; (2) lack of data does not equate to lack of hazard, exposure, or risk; (3) populations at greater risk, including those that are more susceptible or more highly exposed, must be better identified and protected to account for their real-world risks; (4) hazard and risk assessments should not assume existence of a “safe” or “no-risk” level of chemical exposure in the diverse general population; and (5) hazard and risk assessments must evaluate and account for financial conflicts of interest in the body of evidence. While many of these recommendations focus specifically on the EPA, they are general principles for environmental health that could be adopted by any agency or entity engaged in exposure, hazard, and risk assessment. We also detail recommendations for four priority areas in companion papers (exposure assessment methods, human variability assessment, methods for quantifying non-cancer health outcomes, and a framework for defining chemical classes). These recommendations constitute key steps for improved evidence-based environmental health decision-making and public health protection.
}, number={SUPPL 1}, journal={ENVIRONMENTAL HEALTH}, author={Woodruff, Tracey J. and Rayasam, Swati D. G. and Axelrad, Daniel A. and Koman, Patricia D. and Chartres, Nicholas and Bennett, Deborah H. and Birnbaum, Linda S. and Brown, Phil and Carignan, Courtney C. and Cooper, Courtney and et al.}, year={2023}, month={Jan} }
 @misc{maffini_rayasam_axelrad_birnbaum_cooper_franjevic_macroy_nachman_patisaul_rodgers_et al._2023, title={Advancing the science on chemical classes}, volume={21}, ISSN={["1476-069X"]}, DOI={10.1186/s12940-022-00919-y}, abstractNote={Abstract
                Background
                Hazard identification, risk assessment, regulatory, and policy activity are usually conducted on a chemical-by-chemical basis. Grouping chemicals into categories or classes is an underutilized approach that could make risk assessment and management of chemicals more efficient for regulators.
              
                Objective and methods
                While there are some available methods and regulatory frameworks that include the grouping of chemicals (e.g.,same molecular mechanism or similar chemical structure) there has not been a comprehensive evaluation of these different approaches nor a recommended course of action to better consider chemical classes in decision-making. This manuscript: 1) reviews current national and international approaches to grouping; 2) describes how groups could be defined based on the decision context (e.g., hazard/risk assessment, restrictions, prioritization, product development) and scientific considerations (e.g., intrinsic physical-chemical properties); 3) discusses advantages of developing a decision tree approach for grouping; 4) uses ortho-phthalates as a case study to identify and organize frameworks that could be used across agencies; and 5) discusses opportunities to advance the class concept within various regulatory decision-making scenarios.
              
                Results
                Structural similarity was the most common grouping approach for risk assessment among regulatory agencies (national and state level) and non-regulatory organizations, albeit with some variations in its definition. Toxicity to the same target organ or to the same biological function was also used in a few cases. The phthalates case study showed that a decision tree approach for grouping should include questions about uses regulated by other agencies to encourage more efficient, coherent, and protective chemical risk management.
              
                Discussion and conclusion
                Our evaluation of how classes of chemicals are defined and used identified commonalities and differences based on regulatory frameworks, risk assessments, and business strategies. We also identified that using a class-based approach could result in a more efficient process to reduce exposures to multiple hazardous chemicals and, ultimately, reduce health risks. We concluded that, in the absence of a prescribed method, a decision tree approach could facilitate the selection of chemicals belonging to a pre-defined class (e.g., chemicals with endocrine-disrupting activity; organohalogen flame retardants [OFR]) based on the decision-making context (e.g., regulatory risk management).
              }, number={SUPPL 1}, journal={ENVIRONMENTAL HEALTH}, author={Maffini, Maricel V. and Rayasam, Swati D. G. and Axelrad, Daniel A. and Birnbaum, Linda S. and Cooper, Courtney and Franjevic, Shari and MacRoy, Patrick M. and Nachman, Keeve E. and Patisaul, Heather B. and Rodgers, Kathryn M. and et al.}, year={2023}, month={Jan} }
 @article{newell_patisaul_2023, title={Developmental organophosphate flame retardant exposure disrupts adult hippocampal neurogenesis in Wistar rats}, volume={99}, ISSN={["1872-9711"]}, DOI={10.1016/j.neuro.2023.09.009}, abstractNote={Organophosphate flame retardant (OPFR) contamination is ubiquitous and bio-monitoring studies have shown that human exposure is widespread and may be unavoidable. OPFRs bear structural similarities to known neurotoxicants such as organophosphate insecticides and have been shown to have both endocrine disrupting and developmental neurotoxic effects. The perinatal period in rodents represents a critical period in the organization of the developing nervous system and insults during this time can impart profound changes on the trajectory of neural development and function, lasting into adulthood. Adult hippocampal neurogenesis (AHN) facilitates dentate gyrus function and broader hippocampal circuit activity in adults; however, the neurogenic potential of this process in adulthood is vulnerable to disruption by exogenous factors during early life. We sought to assess the impact of OPFRs on AHN in offspring of dams exposed during gestation and lactation. Results indicate that developmental OPFR exposure has significant, sex specific impacts on multiple markers of AHN in the dentate gyrus of rats. In males, OPFR exposure significantly reduced the number of neural progenitors the number of new/immature neurons and reduced dentate gyrus volume. In females, exposure increased the number of neural progenitors, decreased the number of new/immature neurons, but had no significant effect on dentate gyrus volume. These results further elucidate the developmental neurotoxic properties of OPFRs, emphasize the long-term impact of early life OPFR exposure on neural processes, and highlight the importance of including sex as a biological variable in neurotoxicology research.}, journal={NEUROTOXICOLOGY}, author={Newell, Andrew J. and Patisaul, Heather B.}, year={2023}, month={Dec}, pages={104–114} }
 @article{marinello_gillera_han_richardson_st armour_horman_patisaul_2023, title={Gestational exposure to FireMaster® 550 (FM 550) disrupts the placenta-brain axis in a socially monogamous rodent species, the prairie vole (<i>Microtus ochrogaster</i>)}, volume={576}, ISSN={["1872-8057"]}, DOI={10.1016/j.mce.2023.112041}, abstractNote={Gestational flame retardant (FR) exposure has been linked to heightened risk of neurodevelopmental disorders, but the mechanisms remain largely unknown. Historically, toxicologists have relied on traditional, inbred rodent models, yet those do not always best model human vulnerability or biological systems, especially social systems. Here we used prairie voles (Microtus ochrogaster), a monogamous and bi-parental rodent, leveraged for decades to decipher the underpinnings of social behaviors, to examine the impact of fetal FR exposure on gene targets in the mid-gestational placenta and fetal brain. We previously established gestational exposure to the commercial mixture Firemaster 550 (FM 550) impairs sociality, particularly in males. FM 550 exposure disrupted placental monoamine production, particularly serotonin, and genes required for axon guidance and cellular respiration in the fetal brains. Effects were dose and sex specific. These data provide insights on the mechanisms by which FRs impair neurodevelopment and later in life social behaviors.}, journal={MOLECULAR AND CELLULAR ENDOCRINOLOGY}, author={Marinello, William P. and Gillera, Sagi Enicole A. and Han, Yoonhee and Richardson, Jason R. and St Armour, Genevieve and Horman, Brian M. and Patisaul, Heather B.}, year={2023}, month={Oct} }
 @article{newell_jima_reading_patisaul_2023, title={Machine learning reveals common transcriptomic signatures across rat brain and placenta following developmental organophosphate ester exposure}, volume={7}, ISSN={["1096-0929"]}, DOI={10.1093/toxsci/kfad062}, abstractNote={Abstract
               Toxicogenomics is a critical area of inquiry for hazard identification and to identify both mechanisms of action and potential markers of exposure to toxic compounds. However, data generated by these experiments are highly dimensional and present challenges to standard statistical approaches, requiring strict correction for multiple comparisons. This stringency often fails to detect meaningful changes to low expression genes and/or eliminate genes with small but consistent changes particularly in tissues where slight changes in expression can have important functional differences, such as brain. Machine learning offers an alternative analytical approach for “omics” data that effectively sidesteps the challenges of analyzing highly dimensional data. Using 3 rat RNA transcriptome sets, we utilized an ensemble machine learning approach to predict developmental exposure to a mixture of organophosphate esters (OPEs) in brain (newborn cortex and day 10 hippocampus) and late gestation placenta of male and female rats, and identified genes that informed predictor performance. OPE exposure had sex specific effects on hippocampal transcriptome, and significantly impacted genes associated with mitochondrial transcriptional regulation and cation transport in females, including voltage-gated potassium and calcium channels and subunits. To establish if this holds for other tissues, RNAseq data from cortex and placenta, both previously published and analyzed via a more traditional pipeline, were reanalyzed with the ensemble machine learning methodology. Significant enrichment for pathways of oxidative phosphorylation and electron transport chain was found, suggesting a transcriptomic signature of OPE exposure impacting mitochondrial metabolism across tissue types and developmental epoch. Here we show how machine learning can complement more traditional analytical approaches to identify vulnerable “signature” pathways disrupted by chemical exposures and biomarkers of exposure.}, journal={TOXICOLOGICAL SCIENCES}, author={Newell, Andrew J. and Jima, Dereje and Reading, Benjamin and Patisaul, Heather B.}, year={2023}, month={Jul} }
 @article{schkoda_horman_witchey_jansson_macari_patisaul_2023, title={Skeletal effects following developmental flame-retardant exposure are specific to sex and chemical class in the adult Wistar rat}, volume={5}, ISSN={["2673-3080"]}, DOI={10.3389/ftox.2023.1216388}, abstractNote={Introduction: Accumulating evidence reveals that endocrine disrupting chemicals (EDCs) can disrupt aspects of metabolic programming, suggesting that skeletal development may be at risk, a possibility that is rarely examined. The commercial flame retardant (FR) mixture, Firemaster 550 (FM 550), has repeatedly been shown to negatively influence metabolic programming, raising concerns that skeletal integrity may consequently be impaired. We have previously shown that gestational and lactational exposure to 1,000 µg FM 550 negatively affected sex-specific skeletal traits in male, but not female, rats assessed at 6 months of age. Whether this outcome is primarily driven by the brominated (BFR) or organophosphate ester (OPFR) portions of the mixture or the effects persist to older ages is unknown.Materials and methods: To address this, in the present study, dams were orally exposed throughout gestation and lactation to either 1,000 μg BFR, 1,000 µg OPFR, or 2,000 µg FM 550. Offspring (n = 8/sex/exposure) were weaned at PND 21 and assessed for femoral cortical and trabecular bone parameters at 8 months of age by high-resolution X-ray micro-computed tomography (micro-CT). Serum levels of serotonin, osteocalcin, alkaline phosphatase, and calcium were quantified.Results: FM 550 affected both sexes, but the females were more appreciably impacted by the OPFRs, while the males were more vulnerable to the BFRs.Conclusion: Although sex specificity was expected due to the sexual dimorphic nature of skeletal physiology, the mechanisms accounting for the male- and female-specific phenotypes remain to be determined. Future work aims to clarify these unresolved issues.}, journal={FRONTIERS IN TOXICOLOGY}, author={Schkoda, Stacy and Horman, Brian and Witchey, Shannah K. and Jansson, Anton and Macari, Soraia and Patisaul, Heather B.}, year={2023}, month={Jul} }
 @article{marinello_gillera_huang_rollman_reif_patisaul_2023, title={Uncovering the common factors of chemical exposure and behavior: Evaluating behavioral effects across a testing battery using factor analysis}, volume={99}, ISSN={["1872-9711"]}, DOI={10.1016/j.neuro.2023.10.012}, abstractNote={Although specific environmental chemical exposures, including flame retardants, are known risk factors for neurodevelopmental disorders (NDDs), direct experimental evidence linking specific chemicals to NDDs is limited. Studies focusing on the mechanisms by which the social processing systems are vulnerable to chemical exposure are underrepresented in the literature, even though social impairments are defining characteristics of many NDDs. We have repeatedly demonstrated that exposure to Firemaster 550 (FM 550), a prevalent flame retardant mixture used in foam-based furniture and infant products, can adversely impact a variety of behavioral endpoints. Our recent work in prairie voles (Microtus ochrogaster), a prosocial animal model, demonstrated that perinatal exposure to FM 550 sex specifically impacts socioemotional behavior. Here, we utilized a factor analysis approach on a battery of behavioral data from our prior study to extract underlying factors that potentially explain patterns within the FM 550 behavior data. This approach identified which aspects of the behavioral battery are most robust and informative, an outcome critical for future study designs. Pearson's correlation identified behavioral endpoints associated with distance and stranger interactions that were highly correlated across 5 behavioral tests. Using these behavioral endpoints, exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) extracted 2 factors that could explain the data: Activity (distance traveled endpoints) and Sociability (time spent with a novel conspecific). Exposure to FM 550 significantly decreased Activity and decreased Sociability. This factor analysis approach to behavioral data offers the advantages of modeling numerous measured variables and simplifying the data set by presenting the data in terms of common, overarching factors in terms of behavioral function.}, journal={NEUROTOXICOLOGY}, author={Marinello, William P. and Gillera, Sagi Enicole A. and Huang, Lynn and Rollman, John and Reif, David M. and Patisaul, Heather B.}, year={2023}, month={Dec}, pages={264–273} }
 @article{joglekar_cauley_lipsich_corcoran_patisaul_levin_meyer_mccarthy_murphy_2022, title={Developmental nicotine exposure and masculinization of the rat preoptic area}, volume={89}, ISSN={["1872-9711"]}, DOI={10.1016/j.neuro.2022.01.005}, abstractNote={Nicotine is a neuroteratogenic component of tobacco smoke, e-cigarettes, and other products and can exert sex-specific effects in the developing brain, likely mediated through sex hormones. Estradiol modulates expression of nicotinic acetylcholine receptors in rats, and plays critical roles in neurodevelopmental processes, including sexual differentiation of the brain. Here, we examined the effects of developmental nicotine exposure on the sexual differentiation of the preoptic area (POA), a brain region that normally displays robust structural sexual dimorphisms and controls adult mating behavior in rodents. Using a rat model of gestational exposure, developing pups were exposed to nicotine (2 mg/kg/day) via maternal osmotic minipump (subcutaneously, sc) throughout the critical window for brain sexual differentiation. At postnatal day (PND) 4, a subset of offspring was analyzed for epigenetic effects in the POA. At PND40, all offspring were gonadectomized, implanted with a testosterone-releasing capsule (sc), and assessed for male sexual behavior at PND60. Following sexual behavior assessment, the area of the sexually dimorphic nucleus of the POA (SDN-POA) was measured using immunofluorescent staining techniques. In adults, normal sex differences in male sexual behavior and in the SDN-POA area were eliminated in nicotine-treated animals. Using novel analytical approaches to evaluate overall masculinization of the adult POA, we identified significant masculinization of the nicotine-treated female POA. In neonates (PND4), nicotine exposure induced trending alterations in methylation-dependent masculinizing gene expression and DNA methylation levels at sexually-dimorphic differentially methylated regions, suggesting that developmental nicotine exposure is capable of triggering masculinization of the rat POA via epigenetic mechanisms.}, journal={NEUROTOXICOLOGY}, author={Joglekar, Rashmi and Cauley, Marty and Lipsich, Taylor and Corcoran, David L. and Patisaul, Heather B. and Levin, Edward D. and Meyer, Joel N. and McCarthy, Margaret M. and Murphy, Susan K.}, year={2022}, month={Mar}, pages={41–54} }
 @article{adibi_christiansen_fenton_holloway_patisaul_2022, title={Editorial: Women in developmental and reproductive toxicology: 2021}, volume={4}, ISSN={2673-3080}, url={http://dx.doi.org/10.3389/ftox.2022.1026314}, DOI={10.3389/ftox.2022.1026314}, abstractNote={EDITORIAL article Front. Toxicol., 03 October 2022Sec. Developmental and Reproductive Toxicology Volume 4 - 2022 | https://doi.org/10.3389/ftox.2022.1026314}, journal={Frontiers in Toxicology}, publisher={Frontiers Media SA}, author={Adibi, Jennifer J. and Christiansen, Sofie and Fenton, Suzanne E. and Holloway, Alison and Patisaul, Heather B.}, year={2022}, month={Oct} }
 @article{marinello_gillera_fanning_malinsky_rhodes_horman_patisaul_2022, title={Effects of developmental exposure to FireMaster (R) 550 (FM 550) on microglia density, reactivity and morphology in a prosocial animal model}, volume={91}, ISSN={["1872-9711"]}, url={http://dx.doi.org/10.1016/j.neuro.2022.04.015}, DOI={10.1016/j.neuro.2022.04.015}, abstractNote={Microglia are known to shape brain sex differences critical for social and reproductive behaviors. Chemical exposures can disrupt brain sexual differentiation but there is limited data regarding how they may impact microglia distribution and function. We focused on the prevalent flame retardant mixture Firemaster 550 (FM 550) which is used in foam-based furniture and infant products including strollers and nursing pillows because it disrupts sexually dimorphic behaviors. We hypothesized early life FM 550 exposure would disrupt microglial distribution and reactivity in brain regions known to be highly sexually dimorphic or associated with social disorders in humans. We used prairie voles (Microtus ochrogaster) because they display spontaneous prosocial behaviors not seen in rats or mice and are thus a powerful model for studying chemical exposure-related impacts on social behaviors and their underlying neural systems. We have previously demonstrated that perinatal FM 550 exposure sex-specifically impacts socioemotional behaviors in prairie voles. We first established that, unlike in rats, the postnatal colonization of the prairie vole brain is not sexually dimorphic. Vole dams were then exposed to FM 550 (0, 500, 1000, 2000 µg/day) via subcutaneous injections through gestation, and pups were directly exposed beginning the day after birth until weaning. Adult offspring’s brains were assessed for number and type (ramified, intermediate, ameboid) of microglia in the medial prefrontal cortex (mPFC), cerebellum (lobules VI-VII) and amygdala. Effects were sex- and dose-specific in the regions of interests. Overall, FM 550 exposure resulted in reduced numbers of microglia in most regions examined, with the 1000 µg FM 550 exposed males particularly affected. To further quantify differences in microglia morphology in the 1000 µg FM 550 group, Sholl and skeleton analysis were carried out on individual microglia. Microglia from control females had a more ramified phenotype compared to control males while 1000 µg FM 550-exposed males had decreased branching and ramification compared to same-sex controls. Future studies will examine the impact on the exposure to FM 550 on microglia during development given the critical role of these cells in shaping neural circuits.}, journal={NEUROTOXICOLOGY}, publisher={Elsevier BV}, author={Marinello, William P. and Gillera, Sagi Enicole A. and Fanning, Marley J. and Malinsky, Lacey B. and Rhodes, Cassie L. and Horman, Brian M. and Patisaul, Heather B.}, year={2022}, month={Jul}, pages={140–154} }
 @article{witchey_doyle_fredenburg_st armour_horman_odenkirk_aylor_baker_patisaul_2022, title={Impacts of Gestational FireMaster 550 (FM 550) Exposure on the Neonatal Cortex are Sex Specific and Largely Attributable to the Organophosphate Esters}, volume={9}, ISSN={["1423-0194"]}, DOI={10.1159/000526959}, abstractNote={<b><i>Introduction:</i></b> Flame retardants (FRs) are common bodily and environmental pollutants, creating concern about their potential toxicity. We and others have found that the commercial mixture FireMaster® 550 (FM 550) or its individual brominated (BFR) and organophosphate ester (OPFR) components are potential developmental neurotoxicants. Using Wistar rats, we previously reported that developmental exposure to FM 550 or its component classes produced sex- and compound-specific effects on adult socioemotional behaviors. The underlying mechanisms driving the behavioral phenotypes are unknown. <b><i>Methods:</i></b> To further mechanistic understanding, here we conducted transcriptomics in parallel with a novel lipidomics approach using cortical tissues from newborn siblings of the rats in the published behavioral study. Inclusion of lipid composition is significant because it is rarely examined in developmental neurotoxicity studies. Pups were gestationally exposed via oral dosing to the dam to FM 550 or the BFR or OPFR components at environmentally relevant doses. <b><i>Results:</i></b> The neonatal cortex was highly sexually dimorphic in lipid and transcriptome composition, and males were more significantly impacted by FR exposure. Multiple adverse modes of action for the BFRs and OPFRs on neurodevelopment were identified, with the OPFRs being more disruptive than the BFRs via multiple mechanisms including dysregulation of mitochondrial function and disruption of cholinergic and glutamatergic systems. Disrupted mitochondrial function by environmental factors has been linked to a higher risk of autism spectrum disorders and neurodegenerative disorders. Impacted lipid classes included ceramides, sphingomyelins, and triacylglycerides. Robust ceramide upregulation in the OPFR females could suggest a heightened risk of brain metabolic disease. <b><i>Conclusions:</i></b> This study reveals multiple mechanisms by which the components of a common FR mixture are developmentally neurotoxic and that the OPFRs may be the compounds of greatest concern. }, journal={NEUROENDOCRINOLOGY}, author={Witchey, S. K. and Doyle, M. G. and Fredenburg, J. D. and St Armour, G. and Horman, B. and Odenkirk, M. T. and Aylor, D. L. and Baker, E. S. and Patisaul, H. B.}, year={2022}, month={Sep} }
 @article{gillera_marinello_nelson_horman_patisaul_2022, title={Individual and Combined Effects of Paternal Deprivation and Developmental Exposure to Firemaster 550 on Socio-Emotional Behavior in Prairie Voles}, volume={10}, ISSN={["2305-6304"]}, url={https://doi.org/10.3390/toxics10050268}, DOI={10.3390/toxics10050268}, abstractNote={The prevalence of neurodevelopmental disorders (NDDs) is rapidly rising, suggesting a confluence of environmental factors that are likely contributing, including developmental exposure to environmental contaminants. Unfortunately, chemical exposures and social stressors frequently occur simultaneously in many communities, yet very few studies have sought to establish the combined effects on neurodevelopment or behavior. Social deficits are common to many NDDs, and we and others have shown that exposure to the chemical flame retardant mixture, Firemaster 550 (FM 550), or paternal deprivation impairs social behavior and neural function. Here, we used a spontaneously prosocial animal model, the prairie vole (Microtus ochrogaster), to explore the effects of perinatal chemical (FM 550) exposure alone or in combination with an early life stressor (paternal absence) on prosocial behavior. Dams were exposed to vehicle (sesame oil) or 1000 µg FM 550 orally via food treats from conception through weaning and the paternal absence groups were generated by removing the sires the day after birth. Adult offspring of both sexes were then subjected to open-field, sociability, and a partner preference test. Paternal deprivation (PD)-related effects included increased anxiety, decreased sociability, and impaired pair-bonding in both sexes. FM 550 effects include heightened anxiety and partner preference in females but reduced partner preference in males. The combination of FM 550 exposure and PD did not exacerbate any behaviors in either sex except for distance traveled by females in the partner preference test and, to a lesser extent, time spent with, and the number of visits to the non-social stimulus by males in the sociability test. FM 550 ameliorated the impacts of parental deprivation on partner preference behaviors in both sexes. This study is significant because it provides evidence that chemical and social stressors can have unique behavioral effects that differ by sex but may not produce worse outcomes in combination.}, number={5}, journal={TOXICS}, author={Gillera, Sagi Enicole A. and Marinello, William P. and Nelson, Mason A. and Horman, Brian M. and Patisaul, Heather B.}, year={2022}, month={May} }
 @article{newell_kapps_cai_rai_st armour_horman_rock_witchey_greenbaum_patisaul_2023, title={Maternal organophosphate flame retardant exposure alters the developing mesencephalic dopamine system in fetal rat}, volume={191}, ISSN={["1096-0929"]}, DOI={10.1093/toxsci/kfac137}, abstractNote={AbstractOrganophosphate flame retardants (OPFRs) have become the predominant substitution for legacy brominated flame retardants but there is concern about their potential developmental neurotoxicity (DNT). OPFRs readily dissociate from the fireproofed substrate to the environment, and they (or their metabolites) have been detected in diverse matrices including air, water, soil, and biota, including human urine and breastmilk. Given this ubiquitous contamination, it becomes increasingly important to understand the potential effects of OPFRs on the developing nervous system. We have previously shown that maternal exposure to OPFRs results in neuroendocrine disruption, alterations to developmental metabolism of serotonin (5-HT) and axonal extension in male fetal rats, and potentiates adult anxiety-like behaviors. The development of the serotonin and dopamine systems occur in parallel and interact, therefore, we first sought to enhance our prior 5-HT work by first examining the ascending 5-HT system on embryonic day 14 using whole mount clearing of fetal heads and 3-dimensional (3D) brain imaging. We also investigated the effects of maternal OPFR exposure on the development of the mesocortical dopamine system in the same animals through 2-dimensional and 3D analysis following immunohistochemistry for tyrosine hydroxylase (TH). Maternal OPFR exposure induced morphological changes to the putative ventral tegmental area and substantia nigra in both sexes and reduced the overall volume of this structure in males, whereas 5-HT nuclei were unchanged. Additionally, dopaminergic axogenesis was disrupted in OPFR exposed animals, as the dorsoventral spread of ventral telencephalic TH afferents were greater at embryonic day 14, while sparing 5-HT fibers. These results indicate maternal exposure to OPFRs alters the development trajectory of the embryonic dopaminergic system and adds to growing evidence of OPFR DNT.}, number={2}, journal={TOXICOLOGICAL SCIENCES}, author={Newell, Andrew J. and Kapps, Victoria A. and Cai, Yuheng and Rai, Mani Ratnam and St Armour, Genevieve and Horman, Brian M. and Rock, Kylie D. and Witchey, Shannah K. and Greenbaum, Alon and Patisaul, Heather B.}, year={2023}, month={Feb}, pages={357–373} }
 @article{sombers_patisaul_2022, title={Virtual Issue: Neurotoxicology}, volume={13}, ISSN={["1948-7193"]}, DOI={10.1021/acschemneuro.2c00375}, abstractNote={ADVERTISEMENT RETURN TO ISSUEEditorialNEXTVirtual Issue: NeurotoxicologyLeslie A. SombersLeslie A. SombersMore by Leslie A. Sombers and Heather B. PatisaulHeather B. PatisaulMore by Heather B. PatisaulCite this: ACS Chem. Neurosci. 2022, 13, 15, 2238–2239Publication Date (Web):August 3, 2022Publication History Received2 July 2022Published online3 August 2022Published inissue 3 August 2022https://pubs.acs.org/doi/10.1021/acschemneuro.2c00375https://doi.org/10.1021/acschemneuro.2c00375editorialACS PublicationsCopyright © Published 2022 by American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views704Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (1 MB) Get e-AlertscloseSUBJECTS:Bacteria,Central nervous system,Diseases and disorders,Environmental pollution,Toxicology Get e-Alerts}, number={15}, journal={ACS CHEMICAL NEUROSCIENCE}, author={Sombers, Leslie A. and Patisaul, Heather B.}, year={2022}, month={Aug}, pages={2238–2239} }
 @article{patisaul_behl_birnbaum_blum_diamond_fernandez_hogberg_kwiatkowski_page_soehl_et al._2021, title={Beyond Cholinesterase Inhibition: Developmental Neurotoxicity of Organophosphate Ester Flame Retardants and Plasticizers}, volume={129}, ISSN={["1552-9924"]}, DOI={10.1289/EHP9285}, abstractNote={Background: To date, the toxicity of organophosphate esters has primarily been studied regarding their use as pesticides and their effects on the neurotransmitter acetylcholinesterase (AChE). Currently, flame retardants and plasticizers are the two largest market segments for organophosphate esters and they are found in a wide variety of products, including electronics, building materials, vehicles, furniture, car seats, plastics, and textiles. As a result, organophosphate esters and their metabolites are routinely found in human urine, blood, placental tissue, and breast milk across the globe. It has been asserted that their neurological effects are minimal given that they do not act on AChE in precisely the same way as organophosphate ester pesticides. Objectives: This commentary describes research on the non-AChE neurodevelopmental toxicity of organophosphate esters used as flame retardants and plasticizers (OPEs). Studies in humans, mammalian, nonmammalian, and in vitro models are presented, and relevant neurodevelopmental pathways, including adverse outcome pathways, are described. By highlighting this scientific evidence, we hope to elevate the level of concern for widespread human exposure to these OPEs and to provide recommendations for how to better protect public health. Discussion: Collectively, the findings presented demonstrate that OPEs can alter neurodevelopmental processes by interfering with noncholinergic pathways at environmentally relevant doses. Application of a pathways framework indicates several specific mechanisms of action, including perturbation of glutamate and gamma-aminobutyric acid and disruption of the endocrine system. The effects may have implications for the development of cognitive and social skills in children. Our conclusion is that concern is warranted for the developmental neurotoxicity of OPE exposure. We thus describe important considerations for reducing harm and to provide recommendations for government and industry decision makers. https://doi.org/10.1289/EHP9285}, number={10}, journal={ENVIRONMENTAL HEALTH PERSPECTIVES}, author={Patisaul, Heather B. and Behl, Mamta and Birnbaum, Linda S. and Blum, Arlene and Diamond, Miriam L. and Fernandez, Seth Rojello and Hogberg, Helena T. and Kwiatkowski, Carol F. and Page, Jamie D. and Soehl, Anna and et al.}, year={2021}, month={Oct} }
 @misc{patisaul_2021, title={Endocrine disruption and reproductive disorders: impacts on sexually dimorphic neuroendocrine pathways}, volume={162}, ISSN={["1470-1626"]}, DOI={10.1530/REP-20-0596}, abstractNote={We are all living with hundreds of anthropogenic chemicals in our bodies every day, a situation that threatens the reproductive health of present and future generations. This review focuses on endocrine-disrupting compounds (EDCs), both naturally occurring and man-made, and summarizes how they interfere with the neuroendocrine system to adversely impact pregnancy outcomes, semen quality, age at puberty, and other aspects of human reproductive health. While obvious malformations of the genitals and other reproductive organs are a clear sign of adverse reproductive health outcomes and injury to brain sexual differentiation, the hypothalamic-pituitary-gonadal (HPG) axis can be much more difficult to discern, particularly in humans. It is well-established that, over the course of development, gonadal hormones shape the vertebrate brain such that sex-specific reproductive physiology and behaviors emerge. Decades of work in neuroendocrinology have elucidated many of the discrete and often very short developmental windows across pre- and postnatal development in which this occurs. This has allowed toxicologists to probe how EDC exposures in these critical windows can permanently alter the structure and function of the HPG axis. This review includes a discussion of key EDC principles including how latency between exposure and the emergence of consequential health effects can be long, along with a summary of the most common and less well-understood EDC modes of action. Extensive examples of how EDCs are impacting human reproductive health, and evidence that they have the potential for multi-generational physiological and behavioral effects are also provided.}, number={5}, journal={REPRODUCTION}, author={Patisaul, Heather B.}, year={2021}, month={Nov}, pages={F111–F130} }
 @article{krentzel_kimble_dorris_horman_meitzen_patisaul_2021, title={FireMaster (R) 550 (FM 550) exposure during the perinatal period impacts partner preference behavior and nucleus accumbens core medium spiny neuron electrophysiology in adult male and female prairie voles, Microtus ochrogaster}, volume={134}, ISSN={["1095-6867"]}, DOI={10.1016/j.yhbeh.2021.105019}, abstractNote={One of the most widely used flame retardant (FR) mixtures in household products is Firemaster 550 (FM 550). FM 550 leaches from items such as foam-based furniture and infant products, resulting in contamination of the household environment and biota. Previous studies indicate sex-specific behavioral deficits in rodents and zebrafish in response to developmental FM 550 exposure. These deficits include impacts on social and attachment behaviors in a prosocial rodent: the prairie vole (Microtus ochrogaster). The prairie vole is a laboratory-acclimated rodent that exhibits spontaneous attachment behaviors including pair bonding. Here we extend previous work by addressing how developmental exposure to FM 550 impacts pair bonding strength via an extended-time partner preference test, as well as neuron electrophysiological properties in a region implicated in pair bond behavior, the nucleus accumbens (NAcc) core. Dams were exposed to vehicle or 1000 μg of FM 550 via subcutaneous injections throughout gestation, and female and male pups were directly exposed beginning the day after birth until weaning. Pair bond behavior of adult female and male offspring was assessed using a three hour-long partner preference test. Afterwards, acute brain slices of the NAcc core were produced and medium spiny neuron electrophysiological attributes recorded via whole cell patch-clamp. Behavioral impacts were sex-specific. Partner preference behavior was increased in exposed females but decreased in exposed males. Electrophysiological impacts were similar between sexes and specific to attributes related to input resistance. Input resistance was decreased in neurons recorded from both sexes exposed to FM 550 compared to vehicle. This study supports the hypothesis that developmental exposure to FM 550 impacts attachment behaviors and demonstrates a novel FM 550 effect on neural electrophysiology.}, journal={HORMONES AND BEHAVIOR}, author={Krentzel, Amanda A. and Kimble, Laney C. and Dorris, David M. and Horman, Brian M. and Meitzen, John and Patisaul, Heather B.}, year={2021}, month={Aug} }
 @article{grebe_sharma_freeman_palumbo_patisaul_bales_drea_2021, title={Neural correlates of mating system diversity: oxytocin and vasopressin receptor distributions in monogamous and non-monogamous Eulemur}, volume={11}, ISSN={["2045-2322"]}, DOI={10.1038/s41598-021-83342-6}, abstractNote={AbstractContemporary theory that emphasizes the roles of oxytocin and vasopressin in mammalian sociality has been shaped by seminal vole research that revealed interspecific variation in neuroendocrine circuitry by mating system. However, substantial challenges exist in interpreting and translating these rodent findings to other mammalian groups, including humans, making research on nonhuman primates crucial. Both monogamous and non-monogamous species exist withinEulemur, a genus of strepsirrhine primate, offering a rare opportunity to broaden a comparative perspective on oxytocin and vasopressin neurocircuitry with increased evolutionary relevance to humans. We performed oxytocin and arginine vasopressin 1a receptor autoradiography on 12Eulemurbrains from seven closely related species to (1) characterize receptor distributions across the genus, and (2) examine differences between monogamous and non-monogamous species in regions part of putative “pair-bonding circuits”. We find some binding patterns acrossEulemurreminiscent of olfactory-guided rodents, but others congruent with more visually oriented anthropoids, consistent with lemurs occupying an ‘intermediary’ evolutionary niche between haplorhine primates and other mammalian groups. We find little evidence of a “pair-bonding circuit” inEulemurakin to those proposed in previous rodent or primate research. Mapping neuropeptide receptors in these nontraditional species questions existing assumptions and informs proposed evolutionary explanations about the biological bases of monogamy.}, number={1}, journal={SCIENTIFIC REPORTS}, author={Grebe, Nicholas M. and Sharma, Annika and Freeman, Sara M. and Palumbo, Michelle C. and Patisaul, Heather B. and Bales, Karen L. and Drea, Christine M.}, year={2021}, month={Feb} }
 @article{engel_patisaul_brody_hauser_zota_bennet_swanson_whyatt_2021, title={Neurotoxicity of Ortho-Phthalates: Recommendations for Critical Policy Reforms to Protect Brain Development in Children}, volume={111}, ISSN={["1541-0048"]}, DOI={10.2105/AJPH.2020.306014}, abstractNote={ Robust data from longitudinal birth cohort studies and experimental studies of perinatally exposed animals indicate that exposure to ortho-phthalates can impair brain development and increase risks for learning, attention, and behavioral disorders in childhood. This growing body of evidence, along with known adverse effects on male reproductive tract development, calls for immediate action.  Exposures are ubiquitous; the majority of people are exposed to multiple ortho-phthalates simultaneously. We thus recommend that a class approach be used in assessing health impacts as has been done with other chemical classes. We propose critically needed policy reforms to eliminate ortho-phthalates from products that lead to exposure of pregnant women, women of reproductive age, infants, and children. Specific attention should be focused on reducing exposures among socially vulnerable populations such as communities of color, who frequently experience higher exposures.  Ortho-phthalates are used in a vast array of products and elimination will thus necessitate a multipronged regulatory approach at federal and state levels. The fact that manufacturers and retailers have already voluntarily removed ortho-phthalates from a wide range of products indicates that this goal is feasible. }, number={4}, journal={AMERICAN JOURNAL OF PUBLIC HEALTH}, author={Engel, Stephanie M. and Patisaul, Heather B. and Brody, Charlotte and Hauser, Russ and Zota, Ami R. and Bennet, Deborah H. and Swanson, Maureen and Whyatt, Robin M.}, year={2021}, month={Apr}, pages={687–695} }
 @article{gillera_marinello_cao_horman_stapleton_patisaul_2021, title={Sex-specific Disruption of the Prairie Vole Hypothalamus by Developmental Exposure to a Flame Retardant Mixture}, volume={162}, ISSN={["1945-7170"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85111789129&partnerID=MN8TOARS}, DOI={10.1210/endocr/bqab100}, abstractNote={Abstract
               Prevalence of neurodevelopmental disorders (NDDs) with social deficits is conspicuously rising, particularly in boys. Flame retardants (FRs) have long been associated with increased risk, and prior work by us and others in multiple species has shown that developmental exposure to the common FR mixture Firemaster 550 (FM 550) sex-specifically alters socioemotional behaviors including anxiety and pair bond formation. In rats, FRs have also been shown to impair aspects of osmoregulation. Because vasopressin (AVP) plays a role in both socioemotional behavior and osmotic balance we hypothesized that AVP and its related nonapeptide oxytocin (OT) would be vulnerable to developmental FM 550 exposure. We used the prairie vole (Microtus ochrogaste) to test this because it is spontaneously prosocial. Using siblings of prairie voles used in a prior study that assessed behavioral deficits resulting from developmental FM 550 exposure across 3 doses, here we tested the hypothesis that FM 550 sex-specifically alters AVP and OT neuronal populations in critical nuclei, such as the paraventricular nucleus (PVN), that coordinate those behaviors, as well as related dopaminergic (determined by tyrosine hydroxylase (TH) immunolabeling) populations. Exposed females had fewer AVP neurons in the anterior PVN and more A13 TH neurons in the zona incerta than controls. By contrast, in FM 550 males, A13 TH neuron numbers in the zona incerta were decreased but only in 1 dose group. These results expand on previous work showing evidence of endocrine disruption of OT/AVP pathways, including to subpopulations of PVN AVP neurons that coordinate osmoregulatory functions in the periphery.}, number={8}, journal={ENDOCRINOLOGY}, publisher={The Endocrine Society}, author={Gillera, Sagi Enicole A. and Marinello, William P. and Cao, Kevin T. and Horman, Brian M. and Stapleton, Heather M. and Patisaul, Heather B.}, year={2021}, month={Aug} }
 @article{hudson_shiver_yu_mehta_jima_kane_patisaul_cowley_2021, title={Transcriptomic, proteomic, and metabolomic analyses identify candidate pathways linking maternal cadmium exposure to altered neurodevelopment and behavior}, volume={11}, ISSN={["2045-2322"]}, url={https://europepmc.org/articles/PMC8357970}, DOI={10.1038/s41598-021-95630-2}, abstractNote={AbstractCadmium (Cd) is a ubiquitous toxic heavy metal of major public concern. Despite inefficient placental transfer, maternal Cd exposure impairs fetal growth and development. Increasing evidence from animal models and humans suggests maternal Cd exposure negatively impacts neurodevelopment; however, the underlying molecular mechanisms are unclear. To address this, we utilized multiple -omics approaches in a mouse model of maternal Cd exposure to identify pathways altered in the developing brain. Offspring maternally exposed to Cd presented with enlarged brains proportional to body weights at birth and altered behavior at adulthood. RNA-seq in newborn brains identified exposure-associated increases in Hox gene and myelin marker expression and suggested perturbed retinoic acid (RA) signaling. Proteomic analysis showed altered levels of proteins involved in cellular energy pathways, hypoxic response, and RA signaling. Consistent with transcriptomic and proteomic analyses, we identified increased levels of retinoids in maternally-exposed newborn brains. Metabolomic analyses identified metabolites with significantly altered abundance, supportive of changes to cellular energy pathways and hypoxia. Finally, maternal Cd exposure reduced mitochondrial DNA levels in newborn brains. The identification of multiple pathways perturbed in the developing brain provides a basis for future studies determining the mechanistic links between maternal Cd exposure and altered neurodevelopment and behavior.}, number={1}, journal={SCIENTIFIC REPORTS}, author={Hudson, Kathleen M. and Shiver, Emily and Yu, Jianshi and Mehta, Sanya and Jima, Dereje D. and Kane, Maureen A. and Patisaul, Heather B. and Cowley, Michael}, year={2021}, month={Aug} }
 @article{pace_horman_patisaul_muddiman_2020, title={Analysis of neurotransmitters in rat placenta exposed to flame retardants using IR-MALDESI mass spectrometry imaging}, volume={412}, ISSN={["1618-2650"]}, DOI={10.1007/s00216-020-02626-4}, abstractNote={Chemical exposures can adversely impact fetal development. For many compounds, including common flame retardants, the mechanisms by which this occurs remain unclear, but emerging evidence suggests that disruption at the level of the placenta may play a role. Understanding how the placenta might be vulnerable to chemical exposures is challenging due to its complex structure. The primary objective of this study was to develop a method for detecting placental neurotransmitters and related metabolites without chemical derivatization so changes in the abundance and spatial distribution of neurotransmitters in rat placenta following chemical exposure could be determined using infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging. Without chemical derivatization, 49 neurotransmitters and their related metabolites were putatively identified in untreated rat placenta sections using mass measurement accuracy and spectral accuracy. A few neurotransmitters were less abundant in placentas that were exposed to various flame retardants and were further investigated by KEGG metabolic pathway analysis. Many of these downregulated neurotransmitters shared the same enzyme responsible for metabolism, aromaticl-amino acid decarboxylase, suggesting a mechanistic role. These data constitute a new approach that could help identify novel mechanisms of toxicity in complex tissues. Graphical abstract.}, number={15}, journal={ANALYTICAL AND BIOANALYTICAL CHEMISTRY}, author={Pace, Crystal L. and Horman, Brian and Patisaul, Heather and Muddiman, David C.}, year={2020}, month={Jun}, pages={3745–3752} }
 @article{heindel_belcher_flaws_prins_ho_mao_patisaul_ricke_rosenfeld_soto_et al._2020, title={Data integration, analysis, and interpretation of eight academic CLARITY-BPA studies}, volume={98}, ISSN={["1873-1708"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85089071914&partnerID=MN8TOARS}, DOI={10.1016/j.reprotox.2020.05.014}, abstractNote={"Consortium Linking Academic and Regulatory Insights on BPA Toxicity" (CLARITY-BPA) was a comprehensive "industry-standard" Good Laboratory Practice (GLP)-compliant 2-year chronic exposure study of bisphenol A (BPA) toxicity that was supplemented by hypothesis-driven independent investigator-initiated studies. The investigator-initiated studies were focused on integrating disease-associated, molecular, and physiological endpoints previously found by academic scientists into an industry standard guideline-compliant toxicity study. Thus, the goal of this collaboration was to provide a more comprehensive dataset upon which to base safety standards and to determine whether industry-standard tests are as sensitive and predictive as molecular and disease-associated endpoints. The goal of this report is to integrate the findings from the investigator-initiated studies into a comprehensive overview of the observed impacts of BPA across the multiple organs and systems analyzed. For each organ system, we provide the rationale for the study, an overview of methodology, and summarize major findings. We then compare the results of the CLARITY-BPA studies across organ systems with the results of previous peer-reviewed studies from independent labs. Finally, we discuss potential influences that contributed to differences between studies. Developmental exposure to BPA can lead to adverse effects in multiple organs systems, including the brain, prostate gland, urinary tract, ovary, mammary gland, and heart. As published previously, many effects were at the lowest dose tested, 2.5μg/kg /day, and many of the responses were non-monotonic. Because the low dose of BPA affected endpoints in the same animals across organs evaluated in different labs, we conclude that these are biologically – and toxicologically – relevant.}, journal={REPRODUCTIVE TOXICOLOGY}, author={Heindel, Jerrold J. and Belcher, Scott and Flaws, Jodi A. and Prins, Gail S. and Ho, Shuk-Mei and Mao, Jiude and Patisaul, Heather B. and Ricke, William and Rosenfeld, Cheryl S. and Soto, Ana M. and et al.}, year={2020}, month={Dec}, pages={29–60} }
 @article{macari_rock_santos_lima_szawka_moss_horman_patisaul_2020, title={Developmental Exposure to the Flame Retardant Mixture Firemaster 550 Compromises Adult Bone Integrity in Male but not Female Rats}, volume={21}, ISSN={["1422-0067"]}, DOI={10.3390/ijms21072553}, abstractNote={Flame retardants (FRs) are used in a variety of common items from furniture to carpet to electronics to reduce flammability and combustion, but the potential toxicity of these compounds is raising health concerns globally. Organophosphate FRs (OPFRs) are becoming more prevalent as older, brominated FRs are phased out, but the toxicity of these compounds, and the FR mixtures that contain them, is poorly understood. Work in a variety of in vitro model systems has suggested that FRs may induce metabolic reprogramming such that bone density is compromised at the expense of increasing adiposity. To address this hypothesis, the present studies maternally exposed Wistar rat dams orally across gestation and lactation to 1000 µg daily of the FR mixture Firemaster 550 (FM 550) which contains a mixture of brominated FRs and OPFRs. At six months of age, the offspring of both sexes were examined for evidence of compromised bone composition. Bone density, composition, and marrow were all significantly affected, but only in males. The fact that the phenotype was observed months after exposure suggests that FM 550 altered some fundamental aspect of mesenchymal stem cell reprogramming. The severity of the phenotype and the human-relevance of the dose employed, affirm this is an adverse outcome meriting further exploration.}, number={7}, journal={INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES}, author={Macari, Soraia and Rock, Kylie D. and Santos, Mariana S. and Lima, Virginia T. M. and Szawka, Raphael E. and Moss, Jamal and Horman, Brian and Patisaul, Heather B.}, year={2020}, month={Apr} }
 @article{rock_st armour_horman_phillips_ruis_stewart_jima_muddiman_stapleton_patisaul_2020, title={Effects of Prenatal Exposure to a Mixture of Organophosphhate Flame Ritardants on Placental Gene Expression and Serotonergic Innervaion in the Fetal Rat Brain}, volume={176}, ISSN={["1096-0929"]}, DOI={10.1093/toxsci/kfaa046}, abstractNote={AbstractThere is a growing need to understand the potential neurotoxicity of organophosphate flame retardants (OPFRs) and plasticizers because use and, consequently, human exposure, is rapidly expanding. We have previously shown in rats that developmental exposure to the commercial flame retardant mixture Firemaster 550 (FM 550), which contains OPFRs, results in sex-specific behavioral effects, and identified the placenta as a potential target of toxicity. The placenta is a critical coordinator of fetal growth and neurodevelopment, and a source of neurotransmitters for the developing brain. We have shown in rats and humans that flame retardants accumulate in placental tissue, and induce functional changes, including altered neurotransmitter production. Here, we sought to establish if OPFRs (triphenyl phosphate and a mixture of isopropylated triarylphosphate isomers) alter placental function and fetal forebrain development, with disruption of tryptophan metabolism as a primary pathway of interest. Wistar rat dams were orally exposed to OPFRs (0, 500, 1000, or 2000 μg/day) or a serotonin (5-HT) agonist 5-methoxytryptamine for 14 days during gestation and placenta and fetal forebrain tissues collected for analysis by transcriptomics and metabolomics. Relative abundance of genes responsible for the transport and synthesis of placental 5-HT were disrupted, and multiple neuroactive metabolites in the 5-HT and kynurenine metabolic pathways were upregulated. In addition, 5-HTergic projections were significantly longer in the fetal forebrains of exposed males. These findings suggest that OPFRs have the potential to impact the 5-HTergic system in the fetal forebrain by disrupting placental tryptophan metabolism.}, number={1}, journal={TOXICOLOGICAL SCIENCES}, author={Rock, Kylie D. and St Armour, Genevieve and Horman, Brian and Phillips, Allison and Ruis, Matthew and Stewart, Allison K. and Jima, Dereje and Muddiman, David C. and Stapleton, Heather M. and Patisaul, Heather B.}, year={2020}, month={Jul}, pages={203–223} }
 @article{miller_halbing_patisaul_meitzen_2021, title={Interactions of the estrous cycle, novelty, and light on female and male rat open field locomotor and anxiety-related behaviors}, volume={228}, ISSN={["1873-507X"]}, DOI={10.1016/j.physbeh.2020.113203}, abstractNote={Animal behavior can be modulated by multiple interacting factors. In rodents such as rats, these factors include, among others, the female estrous cycle, exposure to a novel environment, and light. Here, we used the open field test to disassociate differences in behavior resulting from each of these factors by testing the hypothesis that locomotor and anxiety-related behaviors differ between estrous cycle phases in female rats and that novelty and light exposure concurrently influence these behaviors in both female and male rats. Adult female rats were tested twice under red or white light in estrus and diestrus estrous cycle phases. Adult male rats were also tested twice under either red or white light. In females, an interaction between novelty and estrous cycle phase influenced locomotor and anxiety-related behaviors. In males, novelty influenced locomotor and anxiety-related behaviors differentially under red and white light. Light exposure increased anxiety-related behaviors in both males and females, but reduced locomotor behavior only in females. These findings reveal the complexities of behavioral testing and highlight the importance of factors such as the estrous cycle, novelty, and light exposure.}, journal={PHYSIOLOGY & BEHAVIOR}, author={Miller, Christiana K. and Halbing, Amy A. and Patisaul, Heather B. and Meitzen, John}, year={2021}, month={Jan} }
 @article{levin_dow-edwards_patisaul_2021, title={Introduction to sex differences in neurotoxic effects}, volume={83}, ISSN={["1872-9738"]}, DOI={10.1016/j.ntt.2020.106931}, journal={NEUROTOXICOLOGY AND TERATOLOGY}, author={Levin, Edward D. and Dow-Edwards, Diana and Patisaul, Heather}, year={2021} }
 @article{krentzel_proano_patisaul_meitzen_2020, title={Temporal and bidirectional influences of estradiol on voluntary wheel running in adult female and male rats}, volume={120}, ISSN={["1095-6867"]}, DOI={10.1016/j.yhbeh.2020.104694}, abstractNote={The sex steroid hormone 17β-estradiol (estradiol) regulates animal behavior as both a non-rapid hormone signal and as a rapid-acting neuromodulator. By practical necessity, estradiol's divergent temporal actions on rodent behavior are typically studied singularly and in one sex. We hypothesized that estradiol simultaneously acts through both temporal mechanisms to sex-specifically modulate a single behavior; and furthermore, that estradiol action in one temporal domain may regulate action in another. To test this hypothesis, we utilized one of the most robust rat behaviors exhibiting sex differences and estradiol-responsiveness, voluntary wheel running. Adult female and male rats were gonadectomized and exposed to daily repeated estradiol benzoate (EB) injections. Estradiol-sensitive running behavior was continually assessed in both the rapid and non-rapid temporal domains. We found that in female rats, estradiol rapidly decreased voluntary wheel running, but only after prior daily EB injections, supporting the hypothesis that non-rapid estradiol action influences rapid estradiol actions. Males exhibited a similar but less robust response, demonstrating sex-responsiveness. This rapid estradiol-induced decrease in running contrasted to non-rapid estradiol action which overall increased running in both sexes, revealing a bidirectional nature of estradiol's temporal influence. Non-rapid estradiol action also demonstrated sex-responsiveness, as a higher dose of EB was required to induce increased running in males compared to females. These findings indicate that estradiol rapidly, non-rapidly, and bidirectionally modulates wheel running in a sex-responsive manner, and that rapid estradiol action is modulated by non-rapid estradiol action. Overall, these data illustrate estradiol as a pleiotropic sex-responsive neuromodulator of a single behavior across temporal domains.}, journal={HORMONES AND BEHAVIOR}, author={Krentzel, Amanda A. and Proano, Stephanie and Patisaul, Heather B. and Meitzen, John}, year={2020}, month={Apr} }
 @misc{patisaul_2020, title={Achieving CLARITY on bisphenol A, brain and behaviour}, volume={32}, ISSN={["1365-2826"]}, DOI={10.1111/jne.12730}, abstractNote={AbstractThere is perhaps no endocrine disrupting chemical more controversial than bisphenol A (BPA). Comprising a high‐volume production chemical used in a variety of applications, BPA has been linked to a litany of adverse health‐related outcomes, including effects on brain sexual differentiation and behaviour. Risk assessors preferentially rely on classical guideline‐compliant toxicity studies over studies published by academic scientists, and have generally downplayed concerns about the potential risks that BPA poses to human health. It has been argued, however, that, because traditional toxicity studies rarely contain neural endpoints, and only a paucity of endocrine‐sensitive endpoints, they are incapable of fully evaluating harm. To address current controversies on the safety of BPA, the United States National Institute of Environmental Health Sciences, the National Toxicology Program (NTP), and the US Food and Drug Administration established the Consortium Linking Academic and Regulatory Insights on BPA Toxicity (CLARITY‐BPA). CLARITY‐BPA performed a classical regulatory‐style toxicology study (Core study) in conjunction with multiple behavioural, molecular and cellular studies conducted by academic laboratories (grantee studies) using a collaboratively devised experimental framework and the same animals and tissues. This review summarises the results from the grantee studies that focused on brain and behaviour. Evidence of altered neuroendocrine development, including age‐ and sex‐specific expression of oestrogen receptor (ER)α and ERβ, and the abrogation of brain and behavioural sexual dimorphisms, supports the conclusion that developmental BPA exposure, even at doses below what regulatory agencies regard as “safe” for humans, contribute to brain and behavioural change. The consistency and the reproducibility of the effects across CLARITY‐BPA and prior studies using the same animal strain and almost identical experimental conditions are compelling. Combined analysis of all of the data from the CLARITY‐BPA project is underway at the NTP and a final report expected in late 2019.}, number={1}, journal={JOURNAL OF NEUROENDOCRINOLOGY}, author={Patisaul, Heather B.}, year={2020}, month={Jan} }
 @article{la merrill_vandenberg_smith_goodson_browne_patisaul_guyton_kortenkamp_cogliano_woodruff_et al._2020, title={Consensus on the key characteristics of endocrine-disrupting chemicals as a basis for hazard identification}, volume={16}, ISSN={["1759-5037"]}, DOI={10.1038/s41574-019-0273-8}, abstractNote={Abstract
Endocrine-disrupting chemicals (EDCs) are exogenous chemicals that interfere with hormone action, thereby increasing the risk of adverse health outcomes, including cancer, reproductive impairment, cognitive deficits and obesity. A complex literature of mechanistic studies provides evidence on the hazards of EDC exposure, yet there is no widely accepted systematic method to integrate these data to help identify EDC hazards. Inspired by work to improve hazard identification of carcinogens using key characteristics (KCs), we have developed ten KCs of EDCs based on our knowledge of hormone actions and EDC effects. In this Expert Consensus Statement, we describe the logic by which these KCs are identified and the assays that could be used to assess several of these KCs. We reflect on how these ten KCs can be used to identify, organize and utilize mechanistic data when evaluating chemicals as EDCs, and we use diethylstilbestrol, bisphenol A and perchlorate as examples to illustrate this approach.}, number={1}, journal={NATURE REVIEWS ENDOCRINOLOGY}, author={La Merrill, Michele A. and Vandenberg, Laura N. and Smith, Martyn T. and Goodson, William and Browne, Patience and Patisaul, Heather B. and Guyton, Kathryn Z. and Kortenkamp, Andreas and Cogliano, Vincent J. and Woodruff, Tracey J. and et al.}, year={2020}, month={Jan}, pages={45–57} }
 @article{miller_krentzel_patisaul_meitzen_2020, title={Metabotropic glutamate receptor subtype 5 (mGlu5) is necessary for estradiol mitigation of light-induced anxiety behavior in female rats}, volume={214}, ISSN={0031-9384}, url={http://dx.doi.org/10.1016/j.physbeh.2019.112770}, DOI={10.1016/j.physbeh.2019.112770}, abstractNote={Anxiety-related behaviors are influenced by steroid hormones such as 17β-estradiol and environmental stimuli such as acute stressors. For example, rats exhibit increased anxiety-related behaviors in the presence, but not the absence, of light. In females, estradiol potentially mitigates these effects. Experiments across behavioral paradigms and brain regions indicate that estradiol action can be mediated via activation of metabotropic glutamate receptors, including Group I subtype five (mGlu5). mGlu5 has been implicated in mediating estradiol's effects upon psychostimulant-induced behaviors, dopamine release and neuron phenotype in striatal regions. Whether estradiol activation of mGlu5 modulates anxiety or locomotor behavior in the absence of psychostimulants is unknown. Here we test if mGlu5 is necessary for estradiol mitigation of light-induced acute anxiety and locomotor behaviors. Ovariectomized adult female rats were pre-treated with either the mGlu5 antagonist MPEP or saline before estradiol or oil treatment. Anxiety and locomotor behaviors were assessed in the presence or absence of white light to induce high and low acute anxiety behavior phenotypes, respectively. In the presence of white light, estradiol treatment mitigated light-induced anxiety-related behaviors but not overall locomotor activity. MPEP treatment blocked estradiol effects upon light-induced anxiety-related behaviors but did not affect overall locomotor activity. In the absence of white light, estradiol or MPEP treatment did not influence anxiety-related behaviors or locomotor activity, consistent with a low anxiety phenotype. These novel findings indicate that mGlu5 activation is necessary for estradiol mitigation of anxiety-related behaviors induced by an acute stressor.}, journal={Physiology & Behavior}, publisher={Elsevier BV}, author={Miller, Christiana K. and Krentzel, Amanda A. and Patisaul, Heather B. and Meitzen, John}, year={2020}, month={Feb}, pages={112770} }
 @article{ruis_rock_hall_horman_patisaul_stapleton_2019, title={PBDEs Concentrate in the Fetal Portion of the Placenta: Implications for Thyroid Hormone Dysregulation}, volume={160}, ISSN={["1945-7170"]}, DOI={10.1210/en.2019-00463}, abstractNote={Abstract
               During pregnancy, the supply of thyroid hormone (TH) to the fetus is critically important for fetal growth, neural development, metabolism, and maintenance of pregnancy. Additionally, in cases where maternal and placental TH regulation is significantly altered, there is an increased risk of several adverse pregnancy outcomes. It is unclear what may be disrupting placental TH regulation; however, studies suggest that environmental contaminants, such as polybrominated diphenyl ethers (PBDEs), could be playing a role. In this study, Wistar rats were gestationally exposed to a mixture of PBDEs for 10 days. THs and PBDEs were quantified in paired maternal serum, dissected placenta, and fetuses, and mRNA expression of transporters in the placenta was assessed. Significantly higher concentrations of PBDEs were observed in the fetal portion of the placenta compared with the maternal side, suggesting that PBDEs are actively transported across the interface. PBDEs were also quantified in 10 recently collected human maternal and fetal placental tissues; trends paralleled observations in the rat model. We also observed an effect of PBDEs on T3 levels in dam serum, as well as suggestive changes in the T3 levels of the placenta and fetus that varied by fetal sex. mRNA expression in the placenta also significantly varied by fetal sex and dose. These observations suggest the placenta is a significant modifier of fetal exposures, and that PBDEs are impacting TH regulation in a sex-specific manner during this critical window of development.}, number={11}, journal={ENDOCRINOLOGY}, author={Ruis, Matthew T. and Rock, Kylie D. and Hall, Samantha M. and Horman, Brian and Patisaul, Heather B. and Stapleton, Heather M.}, year={2019}, month={Nov}, pages={2748–2758} }
 @article{witchey_fuchs_patisaul_2019, title={Perinatal bisphenol A (BPA) exposure alters brain oxytocin receptor (OTR) expression in a sex- and region- specific manner: A CLARITY-BPA consortium follow-up study}, volume={74}, ISSN={["1872-9711"]}, DOI={10.1016/j.neuro.2019.06.007}, abstractNote={Bisphenol A (BPA) is a well-characterized endocrine disrupting chemical (EDC) used in plastics, epoxy resins and other products. Neurodevelopmental effects of BPA exposure are a major concern with multiple rodent and human studies showing that early life BPA exposure may impact the developing brain and sexually dimorphic behaviors. The CLARITY-BPA (Consortium Linking Academic and Regulatory Insights on BPA Toxicity) program was established to assess multiple endpoints, including neural, across a wide dose range. Studies from our lab as part of (and prior to) CLARITY-BPA have shown that BPA disrupts estrogen receptor expression in the developing brain, and some evidence of oxytocin (OT) and oxytocin receptor (OTR) disruption in the hypothalamus and amygdala. While BPA disruption of steroid hormone function is well documented, less is known about its capacity to alter nonapeptide signals. In this CLARITY-BPA follow up study, we used remaining juvenile rat tissues to test the hypothesis that developmental BPA exposure affects OTR expression across the brain. Perinatal BPA exposure (2.5, 25, or 2500 μg/kg body weight (bw)/day) spanned gestation and lactation with dams gavaged from gestational day 6 until birth and then the offspring gavaged directly through weaning. Ethinyl estradiol (0.5 μg/kg bw/day) was used as a reference estrogen. Animals of both sexes were sacrificed as juveniles and OTR expression assessed by receptor binding. Our results demonstrate prenatal exposure to BPA can eliminate sex differences in OTR expression in three hypothalamic regions, and that male OTR expression may be more susceptible. Our data also identify a sub-region of the BNST with sexually dimorphic OTR expression not previously reported in juvenile rats that is also susceptible to BPA.}, journal={NEUROTOXICOLOGY}, author={Witchey, Shannah K. and Fuchs, Joelle and Patisaul, Heather B.}, year={2019}, month={Sep}, pages={139–148} }
 @article{rock_gillera_devarasetty_horman_knudsen_birnbaum_fenton_patisaul_2019, title={Sex-specific behavioral effects following developmental exposure to tetrabromobisphenol A (TBBPA) in Wistar rats}, volume={75}, ISSN={0161-813X}, url={http://dx.doi.org/10.1016/j.neuro.2019.09.003}, DOI={10.1016/j.neuro.2019.09.003}, abstractNote={Tetrabromobisphenol A (TBBPA) has become a ubiquitous indoor contaminant due to its widespread use as an additive flame retardant in consumer products. Reported evidence of endocrine disruption and accumulation of TBBPA in brain tissue has raised concerns regarding its potential effects on neurodevelopment and behavior. The goal of the present study was to examine the impact of developmental TBBPA exposure, across a wide range of doses, on sexually dimorphic non-reproductive behaviors in male and female Wistar rats. We first ran a pilot study using a single TBBPA dose hypothesized to produce behavioral effects. Wistar rat dams were orally exposed using cookie treats to 0 or 0.1 mg TBBPA/kg bw daily from gestational day (GD) 9 to postnatal day (PND) 21 to assess offspring (both sexes) activity and anxiety-related behaviors. Significant effects were evident in females, with exposure increasing activity levels. Thus, this dose was used as the lowest TBBPA dose in a subsequent, larger study conducted as part of a comprehensive assessment of TBBPA toxicity. Animals were exposed to 0, 0.1, 25, or 250 mg TBBPA/kg bw daily by oral gavage starting on GD 6 through PND 90 (dosed dams GD 6 – PND 21, dosed offspring PND 22 – PND 90). Significant behavioral findings were observed for male offspring, with increased anxiety-like behavior as the primary phenotype. These findings demonstrate that exposure to environmental contaminants, like TBBPA, can have sex-specific effects on behavior highlighting the vulnerability of the developing brain.}, journal={NeuroToxicology}, publisher={Elsevier BV}, author={Rock, Kylie D. and Gillera, Sagi Enicole A. and Devarasetty, Pratyush and Horman, Brian and Knudsen, Gabriel and Birnbaum, Linda S. and Fenton, Suzanne E. and Patisaul, Heather B.}, year={2019}, month={Dec}, pages={136–147} }
 @misc{vandenberg_prins_patisaul_zoeller_2020, title={The Use and Misuse of Historical Controls in Regulatory Toxicology: Lessons from the CLARITY-BPA Study}, volume={161}, ISSN={["1945-7170"]}, DOI={10.1210/endocr/bqz014}, abstractNote={Abstract
               For many endocrine-disrupting chemicals (EDCs) including Bisphenol A (BPA), animal studies show that environmentally relevant exposures cause harm; human studies are consistent with these findings. Yet, regulatory agencies charged with protecting public health continue to conclude that human exposures to these EDCs pose no risk. One reason for the disconnect between the scientific consensus on EDCs in the endocrinology community and the failure to act in the regulatory community is the dependence of the latter on so-called “guideline studies” to evaluate hazards, and the inability to incorporate independent scientific studies in risk assessment. The Consortium Linking Academic and Regulatory Insights on Toxicity (CLARITY) study was intended to bridge this gap, combining a “guideline” study with independent hypothesis-driven studies designed to be more appropriate to evaluate EDCs. Here we examined an aspect of “guideline” studies, the use of so-called “historical controls,” which are essentially control data borrowed from prior studies to aid in the interpretation of current findings. The US Food and Drug Administration authors used historical controls to question the plausibility of statistically significant BPA-related effects in the CLARITY study. We examined the use of historical controls on 5 outcomes in the CLARITY “guideline” study: mammary neoplasms, pituitary neoplasms, kidney nephropathy, prostate inflammation and adenomas, and body weight. Using US Food and Drug Administration–proposed historical control data, our evaluation revealed that endpoints used in “guideline” studies are not as reproducible as previously held. Combined with other data comparing the effects of ethinyl estradiol in 2 “guideline” studies including CLARITY-BPA, we conclude that near-exclusive reliance on “guideline” studies can result in scientifically invalid conclusions.}, number={5}, journal={ENDOCRINOLOGY}, author={Vandenberg, Laura N. and Prins, Gail S. and Patisaul, Heather B. and Zoeller, R. Thomas}, year={2020}, month={May} }
 @article{patisaul_fenton_aylor_2018, title={Animal models of endocrine disruption}, volume={32}, ISSN={1521-690X}, url={http://dx.doi.org/10.1016/j.beem.2018.03.011}, DOI={10.1016/j.beem.2018.03.011}, abstractNote={Endocrine disrupting chemicals (EDCs) are compounds that alter the structure and function of the endocrine system and may be contributing to disorders of the reproductive, metabolic, neuroendocrine and other complex systems. Typically, these outcomes cannot be modeled in cell-based or other simple systems necessitating the use of animal testing. Appropriate animal model selection is required to effectively recapitulate the human experience, including relevant dosing and windows of exposure, and ensure translational utility and reproducibility. While classical toxicology heavily relies on inbred rats and mice, and focuses on apical endpoints such as tumor formation or birth defects, EDC researchers have used a greater diversity of species to effectively model more subtle but significant outcomes such as changes in pubertal timing, mammary gland development, and social behaviors. Advances in genomics, neuroimaging and other tools are making a wider range of animal models more widely available to EDC researchers.}, number={3}, journal={Best Practice & Research Clinical Endocrinology & Metabolism}, publisher={Elsevier BV}, author={Patisaul, Heather B. and Fenton, Suzanne E. and Aylor, David}, year={2018}, month={Jun}, pages={283–297} }
 @article{prins_patisaul_belcher_vandenberg_2018, title={CLARITY-BPA academic laboratory studies identify consistent low-dose Bisphenol A effects on multiple organ systems}, volume={10}, ISSN={1742-7835}, url={http://dx.doi.org/10.1111/bcpt.13125}, DOI={10.1111/bcpt.13125}, abstractNote={AbstractBisphenol A (BPA) is a high‐production chemical used in a variety of applications worldwide. While BPA has been documented as an endocrine‐disrupting chemical (EDC) having adverse health‐related outcomes in multiple studies, risk assessment for BPA has lagged due to reliance on guideline toxicology studies over academic ones with end‐points considered more sensitive and appropriate. To address current controversies on BPA safety, the United States National Institute of Environmental Health Sciences (NIEHS), the National Toxicology Program (NTP) and the Food and Drug Administration (FDA) established the Consortium Linking Academic and Regulatory Insights on BPA Toxicity (CLARITY‐BPA) using the NCTR Sprague‐Dawley rats. The goal of CLARITY‐BPA is to perform a traditional regulatory toxicology study (Core study) in conjunction with multiple behavioural, molecular and cellular studies by academic laboratories focused on previously identified BPA‐sensitive organ systems (Academic studies). Combined analysis of the data from both study types will be undertaken by the NTP with the aim of resolving uncertainties on BPA toxicity. To date, the Core study has been completed and a draft report released. Most of the academic studies have also been finalized and published in peer‐reviewed journals. In light of this important milestone, the PPTOX‐VI meeting held in the Faroe Islands, 27‐30 May 2018 devoted a plenary session to CLARITY‐BPA with presentations by multiple investigators with the purpose of highlighting key outcome. This MiniReview synthesizes the results of three academic studies presented at this plenary session, evaluates recently published findings by other CLARITY‐BPA academic studies to provide an early combined overview of this emerging data and places this in the context of the Core study findings. This co‐ordinated effort revealed a plethora of significant BPA effects across multiple organ systems and BPA doses with non‐monotonic responses across the dose range utilized. Remarkably consistent across most studies, including the Core study, are low‐dose effects (2.5, 25 and 250 μg BPA/kg body‐weight). Collectively, the findings highlighted herein corroborate a significant body of evidence that documents adverse effects of BPA at doses relevant to human exposures and emphasizes the need for updated risk assessment analysis.}, number={S3}, journal={Basic & Clinical Pharmacology & Toxicology}, publisher={Wiley}, author={Prins, Gail S. and Patisaul, Heather B. and Belcher, Scott M. and Vandenberg, Laura N.}, year={2018}, month={Oct}, pages={14–31} }
 @article{rock_horman_phillips_mcritchie_watson_deese-spruill_jima_sumner_stapleton_patisaul_et al._2018, title={EDC IMPACT: Molecular effects of developmental FM 550 exposure in Wistar rat placenta and fetal forebrain}, volume={7}, ISSN={["2049-3614"]}, DOI={10.1530/ec-17-0373}, abstractNote={Firemaster 550 (FM 550) is a flame retardant (FR) mixture that has become one of the most commonly used FRs in foam-based furniture and baby products. Human exposure to this commercial mixture, composed of brominated and organophosphate components, is widespread. We have repeatedly shown that developmental exposure can lead to sex-specific behavioral effects in rats. Accruing evidence of endocrine disruption and potential neurotoxicity has raised concerns regarding the neurodevelopmental effects of FM 550 exposure, but the specific mechanisms of action remains unclear. Additionally, we observed significant, and in some cases sex-specific, accumulation of FM 550 in placental tissue following gestational exposure. Because the placenta is an important source of hormones and neurotransmitters for the developing brain, it may be a critical target of toxicity to consider in the context of developmental neurotoxicity. Using a mixture of targeted and exploratory approaches, the goal of the present study was to identify possible mechanisms of action in the developing forebrain and placenta. Wistar rat dams were orally exposed to FM 550 (0, 300 or 1000 µg/day) for 10 days during gestation and placenta and fetal forebrain tissue collected for analysis. In placenta, evidence of endocrine, inflammatory and neurotransmitter signaling pathway disruption was identified. Notably, 5-HT turnover was reduced in placental tissue and fetal forebrains indicating that 5-HT signaling between the placenta and the embryonic brain may be disrupted. These findings demonstrate that environmental contaminants, like FM 550, have the potential to impact the developing brain by disrupting normal placental functions.}, number={2}, journal={ENDOCRINE CONNECTIONS}, author={Rock, K. D. and Horman, B. and Phillips, A. L. and McRitchie, S. L. and Watson, S. and Deese-Spruill, J. and Jima, D. and Sumner, S. and Stapleton, H. M. and Patisaul, Heather and et al.}, year={2018}, month={Feb}, pages={305–324} }
 @article{rock_patisaul_2018, title={Environmental Mechanisms of Neurodevelopmental Toxicity}, volume={5}, ISSN={2196-5412}, url={http://dx.doi.org/10.1007/s40572-018-0185-0}, DOI={10.1007/s40572-018-0185-0}, abstractNote={With the incidence of neurodevelopmental disorders on the rise, it is imperative to identify and understand the mechanisms by which environmental contaminants can impact the developing brain and heighten risk. Here, we report on recent findings regarding novel mechanisms of developmental neurotoxicity and highlight chemicals of concern, beyond traditionally defined neurotoxicants.The perinatal window represents a critical and extremely vulnerable period of time during which chemical insult can alter the morphological and functional trajectory of the developing brain. Numerous chemical classes have been associated with alterations in neurodevelopment including metals, solvents, pesticides, and, more recently, endocrine-disrupting compounds. Although mechanisms of neurotoxicity have traditionally been identified as pathways leading to neuronal cell death, neuropathology, or severe neural injury, recent research highlights alternative mechanisms that result in more subtle but consequential changes in the brain and behavior. These emerging areas of interest include neuroendocrine and immune disruption, as well as indirect toxicity via actions on other organs such as the gut and placenta. Understanding of the myriad ways in which the developing brain is vulnerable to chemical exposures has grown tremendously over the past decade. Further progress and implementation in risk assessment is critical to reducing risk of neurodevelopmental disorders.}, number={1}, journal={Current Environmental Health Reports}, publisher={Springer Nature}, author={Rock, Kylie D. and Patisaul, Heather B.}, year={2018}, month={Mar}, pages={145–157} }
 @article{bagley_ekelof_rock_patisaul_muddiman_2018, title={IR-MALDESI mass spectrometry imaging of underivatized neurotransmitters in brain tissue of rats exposed to tetrabromobisphenol A}, volume={410}, ISSN={["1618-2650"]}, DOI={10.1007/s00216-018-1420-0}, abstractNote={There is a pressing need to develop tools for assessing possible neurotoxicity, particularly for chemicals where the mode of action is poorly understood. Tetrabromobisphenol A (TBBPA), a highly abundant brominated flame retardant, has lately been targeted for neurotoxicity analysis by concerned public health entities in the EU and USA because it is a suspected thyroid disruptor and neurotoxicant. In this study, infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) coupled to a Q Exactive Plus mass spectrometer was used for the analysis of neurotransmitters in the brains of rats exposed to TBBPA in gestation and lactation through their mothers. Three neurotransmitters of interest were studied in three selected regions of the brain: caudate putamen, substantia nigra (SN), and dorsal raphe. Stable isotope labeled (SIL) standards were used as internal standards and a means to achieve relative quantification. This study serves as a demonstration of a new application of IR-MALDESI, namely that neurotransmitter distributions can be confidently and rapidly imaged without derivatization.}, number={30}, journal={ANALYTICAL AND BIOANALYTICAL CHEMISTRY}, author={Bagley, M. Caleb and Ekelof, Mans and Rock, Kylie and Patisaul, Heather and Muddiman, David C.}, year={2018}, month={Dec}, pages={7979–7986} }
 @article{vogel_patisaul_arambula_tiezzi_mcgraw_2018, title={Individual Variation in Social Behaviours of Male Lab-reared Prairie voles (Microtus ochrogaster) is Non-heritable and Weakly Associated with V1aR Density}, volume={8}, ISSN={2045-2322}, url={http://dx.doi.org/10.1038/s41598-018-19737-9}, DOI={10.1038/s41598-018-19737-9}, abstractNote={AbstractThe genetic and environmental factors that contribute to pair bonding behaviour remain poorly understood. Prairie voles (Microtus ochrogaster) often, but not always, form stable pair bonds and present an ideal model species for investigating the genetic and environmental factors that influence monogamy. Here, we assessed variation in partner preference, a measure of pair bonding, and related social behaviours in a population of laboratory-reared prairie voles under controlled environmental conditions. We evaluated to what extent variation in these behaviours correlate with vasopressin 1a receptor (V1aR) expression in the ventral pallidum (VP) and retrosplenial cortex (RSC), and estimated the heritability of these behaviours and V1aR expression. We found substantial variation in partner preference and measures of aggression, paternal care, and anxiety-like behaviours, but no correlation between these traits. We also found variation in V1aR density in the VP and RSC can account for behavioural components of paternal care and aggression, but not in partner preference. Heritability estimates of variation in partner preference were low, yet heritability estimates for V1aR expression were high, indicating that the extensive variation in partner preference observed within this population is due largely to environmental plasticity.}, number={1}, journal={Scientific Reports}, publisher={Springer Nature}, author={Vogel, Andrea R. and Patisaul, Heather B. and Arambula, Sheryl E. and Tiezzi, Francesco and McGraw, Lisa A.}, year={2018}, month={Jan}, pages={1396} }
 @article{barrett_patisaul_2018, title={Introduction to the special issue on endocrine disrupting chemicals and behavior}, volume={101}, ISSN={["1095-6867"]}, DOI={10.1016/j.yhbeh.2018.05.009}, journal={HORMONES AND BEHAVIOR}, author={Barrett, Emily S. and Patisaul, Heather B.}, year={2018}, month={May}, pages={1–2} }
 @article{stetzik_sullivan_patisaul_cushing_2018, title={Novel unconditioned prosocial behavior in prairie voles (Microtus ochrogaster) as a model for empathy}, volume={11}, ISSN={1756-0500}, url={http://dx.doi.org/10.1186/s13104-018-3934-0}, DOI={10.1186/s13104-018-3934-0}, abstractNote={In this study, empathy is quantified using a novel social test. Empathy and prosocial behavior are linked to the expression of oxytocin in humans and rodent models. Specifically, prosocial behavior in prairie voles (Microtus ochrogaster) has been linked to the expression of oxytocin in the paraventricular nucleus of the hypothalamus. The animal’s behavior was considered empathic if it spends significantly more time attempting to remove a loos fitting restraint (tether) from the stimulus animal than time in contact with a, simultaneously presented, non-social object similar to the tether. The behavioral data was cross-referenced with the number of neurons expressing oxytocin and arginine vasopressin, as well as the density of dopaminergic neurons (identified by the expression of tyrosine hydroxylase), in the paraventricular nucleus of the hypothalamus. These proteins influence empathic behavior in humans, non-human primates, rats, mice, and prairie voles. The consistency between neuroanatomical mechanisms linked to empathy, and the durations of time spent engaging in empathic contact, support the prediction that the empathic contact in this test is a distinct prosocial behavior, lacking prior behavioral training or the naturally occurring ethological relevance of other prosocial behaviors, and is a measure of empathy.}, number={1}, journal={BMC Research Notes}, publisher={Springer Nature}, author={Stetzik, Lucas A. and Sullivan, Alana W. and Patisaul, Heather B. and Cushing, Bruce S.}, year={2018}, month={Dec} }
 @article{willett_johnson_vogel_patisaul_mcgraw_meitzen_2018, title={Nucleus accumbens core medium spiny neuron electrophysiological properties and partner preference behavior in the adult male prairie vole, Microtus ochrogaster}, volume={119}, ISSN={0022-3077 1522-1598}, url={http://dx.doi.org/10.1152/jn.00737.2017}, DOI={10.1152/jn.00737.2017}, abstractNote={ Medium spiny neurons (MSNs) in the nucleus accumbens have long been implicated in the neurobiological mechanisms that underlie numerous social and motivated behaviors as studied in rodents such as rats. Recently, the prairie vole has emerged as an important model animal for studying social behaviors, particularly regarding monogamy because of its ability to form pair bonds. However, to our knowledge, no study has assessed intrinsic vole MSN electrophysiological properties or tested how these properties vary with the strength of the pair bond between partnered voles. Here we performed whole cell patch-clamp recordings of MSNs in acute brain slices of the nucleus accumbens core (NAc) of adult male voles exhibiting strong and weak preferences for their respective partnered females. We first document vole MSN electrophysiological properties and provide comparison to rat MSNs. Vole MSNs demonstrated many canonical electrophysiological attributes shared across species but exhibited notable differences in excitability compared with rat MSNs. Second, we assessed male vole partner preference behavior and tested whether MSN electrophysiological properties varied with partner preference strength. Male vole partner preference showed extensive variability. We found that decreases in miniature excitatory postsynaptic current amplitude and the slope of the evoked action potential firing rate to depolarizing current injection weakly associated with increased preference for the partnered female. This suggests that excitatory synaptic strength and neuronal excitability may be decreased in MSNs in males exhibiting stronger preference for a partnered female. Overall, these data provide extensive documentation of MSN electrophysiological characteristics and their relationship to social behavior in the prairie vole.  NEW & NOTEWORTHY This research represents the first assessment of prairie vole nucleus accumbens core medium spiny neuron intrinsic electrophysiological properties and probes the relationship between cellular excitability and social behavior. }, number={4}, journal={Journal of Neurophysiology}, publisher={American Physiological Society}, author={Willett, Jaime A. and Johnson, Ashlyn G. and Vogel, Andrea R. and Patisaul, Heather B. and McGraw, Lisa A. and Meitzen, John}, year={2018}, month={Apr}, pages={1576–1588} }
 @article{wang_pehrsson_purushotham_li_zhuo_zhang_lawson_province_krapp_lan_et al._2018, title={The NIEHS TaRGET II Consortium and environmental epigenomics}, volume={36}, ISSN={1087-0156 1546-1696}, url={http://dx.doi.org/10.1038/NBT.4099}, DOI={10.1038/NBT.4099}, number={3}, journal={Nature Biotechnology}, publisher={Springer Science and Business Media LLC}, author={Wang, Ting and Pehrsson, Erica C and Purushotham, Deepak and Li, Daofeng and Zhuo, Xiaoyu and Zhang, Bo and Lawson, Heather A and Province, Michael A and Krapp, Christopher and Lan, Yemin and et al.}, year={2018}, month={Mar}, pages={225–227} }
 @misc{wang_pehrsson_purushotham_li_zhuo_zhang_lawson_province_krapp_lan_et al._2018, title={The NIEHS TaRGET II Consortium and environmental epigenomics}, volume={36}, number={3}, journal={Nature Biotechnology}, author={Wang, T. and Pehrsson, E. C. and Purushotham, D. and Li, D. F. and Zhuo, X. Y. and Zhang, B. and Lawson, H. A. and Province, M. A. and Krapp, C. and Lan, Y. M. and et al.}, year={2018}, pages={225–227} }
 @article{patisaul_2017, title={Chemical Contributions to Neurodevelopmental Disorders}, volume={4}, ISSN={2372-7322 2372-7330}, url={http://dx.doi.org/10.1177/2372732217719909}, DOI={10.1177/2372732217719909}, abstractNote={ Children increasingly receive diagnoses of neurodevelopmental disorders (NDDs). Causes are multifactorial, but growing consensus identifies environmental factors, especially chemical exposures, as primary drivers, with some individuals more genetically susceptible to these external pressures than others. Our current system of chemical management prioritizes rapid commercialization over disease prevention. This strategy privatizes economic benefits but socializes health costs. The evidence linking chemical exposure to neurodevelopmental risk merits greater attention by regulators. Public health concerns, particularly for children and other vulnerable groups, should be elevated in chemical risk assessment. The financial and emotional burden of preventable NDDs on U.S. children and their families calls for comprehensive policy attention. }, number={2}, journal={Policy Insights from the Behavioral and Brain Sciences}, publisher={SAGE Publications}, author={Patisaul, Heather B.}, editor={Fiske, Susan T.Editor}, year={2017}, month={Aug}, pages={123–130} }
 @article{arambula_fuchs_cao_patisaul_2017, title={Effects of perinatal bisphenol A exposure on the volume of sexually-dimorphic nuclei of juvenile rats: A CLARITY-SPA consortium study}, volume={63}, ISSN={["1872-9711"]}, DOI={10.1016/j.neuro.2017.09.002}, abstractNote={Bisphenol A (BPA) is a high volume endocrine disrupting chemical found in a wide variety of products including plastics and epoxy resins. Human exposure is nearly ubiquitous, and higher in children than adults. Because BPA has been reported to interfere with sex steroid hormone signaling, there is concern that developmental exposure, even at levels below the current FDA No Observed Adverse Effect Level (NOAEL) of 5mg/kg body weight (bw)/day, can disrupt brain sexual differentiation. The current studies were conducted as part of the CLARITY-BPA (Consortium Linking Academic and Regulatory Insights on BPA Toxicity) program and tested the hypothesis that perinatal BPA exposure would induce morphological changes in hormone sensitive, sexually dimorphic brain regions. Sprague-Dawley rats were randomly assigned to 5 groups: BPA (2.5, 25, or 2500μg/kgbw/day), a reference estrogen (0.5μg ethinylestradiol (EE2)/kgbw/day), or vehicle. Exposure occurred by gavage to the dam from gestational day 6 until parturition, and then to the offspring from birth through weaning. Unbiased stereology was used to quantify the volume of the sexually dimorphic nucleus (SDN), the anteroventral periventricular nucleus (AVPV), the posterodorsal portion of the medial amygdala (MePD), and the locus coeruleus (LC) at postnatal day 28. No appreciable effects of BPA were observed on the volume of the SDN or LC. However, AVPV volume was enlarged in both sexes, even at levels below the FDA NOAEL. Collectively, these data suggest the developing brain is vulnerable to endocrine disruption by BPA at exposure levels below previous estimates by regulatory agencies.}, journal={NEUROTOXICOLOGY}, author={Arambula, Sheryl E. and Fuchs, Joelle and Cao, Jinyan and Patisaul, Heather B.}, year={2017}, month={Dec}, pages={33–42} }
 @article{patisaul_2017, title={Endocrine Disruption of Vasopressin Systems and Related Behaviors}, volume={8}, ISSN={1664-2392}, url={http://dx.doi.org/10.3389/fendo.2017.00134}, DOI={10.3389/fendo.2017.00134}, abstractNote={Endocrine disrupting chemicals (EDCs) are chemicals that interfere with the organizational or activational effects of hormones. Although the vast majority of the EDC literature focuses on steroid hormone signaling related impacts, growing evidence from a myriad of species reveals that the nonapeptide hormones vasopressin (AVP) and oxytocin (OT) may also be EDC targets. EDCs shown to alter pathways and behaviors coordinated by AVP and/or OT include the plastics component bisphenol A (BPA), the soy phytoestrogen genistein (GEN), and various flame retardants. Many effects are sex specific and likely involve action at nuclear estrogen receptors. Effects include the elimination or reversal of well-characterized sexually dimorphic aspects of the AVP system, including innervation of the lateral septum and other brain regions critical for social and other non-reproductive behaviors. Disruption of magnocellular AVP function has also been reported in rats, suggesting possible effects on hemodynamics and cardiovascular function.}, journal={Frontiers in Endocrinology}, publisher={Frontiers Media SA}, author={Patisaul, Heather B.}, year={2017}, month={Jun} }
 @article{barrett_patisaul_2017, title={Endocrine disrupting chemicals and behavior: Re-evaluating the science at a critical turning point}, volume={96}, ISSN={["1095-6867"]}, DOI={10.1016/j.yhbeh.2017.09.010}, journal={HORMONES AND BEHAVIOR}, author={Barrett, Emily S. and Patisaul, Heather B.}, year={2017}, month={Nov}, pages={A1–A6} }
 @article{dewitt_patisaul_2018, title={Endocrine disruptors and the developing immune system}, volume={10}, ISSN={2468-2020}, url={http://dx.doi.org/10.1016/J.COTOX.2017.12.005}, DOI={10.1016/J.COTOX.2017.12.005}, abstractNote={During development, the immune system intimately communicates with other systems and tissues to shape their form and function and is similarly shaped in return. This process is highly regulated, making the developing immune system highly sensitive to exogenous insults. Modulation that occurs during development may persist through adulthood, resulting in an increased risk of later-life diseases and disorders. The adverse health outcomes that may arise from developmental immunotoxicity (DIT) are extremely varied and can present symptomatically in systems other than the immune system. The close connection that the immune system shares with other systems and tissues also puts the immune system at risk from secondary effects that arise from primary effects in other systems. The endocrine system also is sensitive to exogenous influences; because it works closely with the immune system to influence development from gestation through early life, endocrine disruption also may induce DIT. This short review therefore considers the role of endocrine disruption in DIT and highlights endocrine disrupting chemicals (EDCs) with known DIT effects. Of special importance are microglia, the resident immune cells of the central nervous system that are highly influenced by endogenous endocrine signals during development and are therefore sensitive to effects from exposure to EDCs.}, journal={Current Opinion in Toxicology}, publisher={Elsevier BV}, author={DeWitt, Jamie C. and Patisaul, Heather B.}, year={2018}, month={Aug}, pages={31–36} }
 @article{patisaul_gore_crews_2017, title={Environmental endocrine disruption of brain and behavior}, journal={Hormones, Brain and Behavior, vol 5: Development of Hormone-Behavior Relationships, 3rd edition}, author={Patisaul, H. B. and Gore, A. C. and Crews, D.}, year={2017}, pages={63–88} }
 @misc{webb_moon_dyrszka_rodriguez_cox_patisaul_bushkin_london_2018, title={Neurodevelopmental and neurological effects of chemicals associated with unconventional oil and natural gas operations and their potential effects on infants and children}, volume={33}, ISSN={["2191-0308"]}, DOI={10.1515/reveh-2017-0008}, abstractNote={AbstractHeavy metals (arsenic and manganese), particulate matter (PM), benzene, toluene, ethylbenzene, xylenes (BTEX), polycyclic aromatic hydrocarbons (PAHs) and endocrine disrupting chemicals (EDCs) have been linked to significant neurodevelopmental health problems in infants, children and young adults. These substances are widely used in, or become byproducts of unconventional oil and natural gas (UOG) development and operations. Every stage of the UOG lifecycle, from well construction to extraction, operations, transportation and distribution can lead to air and water contamination. Residents near UOG operations can suffer from increased exposure to elevated concentrations of air and water pollutants. Here we focus on five air and water pollutants that have been associated with potentially permanent learning and neuropsychological deficits, neurodevelopmental disorders and neurological birth defects. Given the profound sensitivity of the developing brain and central nervous system, it is reasonable to conclude that young children who experience frequent exposure to these pollutants are at particularly high risk for chronic neurological diseases. More research is needed to understand the extent of these concerns in the context of UOG, but since UOG development has expanded rapidly in recent years, the need for public health prevention techniques, well-designed studies and stronger state and national regulatory standards is becoming increasingly apparent.}, number={1}, journal={REVIEWS ON ENVIRONMENTAL HEALTH}, author={Webb, Ellen and Moon, Julie and Dyrszka, Larysa and Rodriguez, Brian and Cox, Caroline and Patisaul, Heather and Bushkin, Sheila and London, Eric}, year={2018}, month={Mar}, pages={3–29} }
 @article{arambula_jima_patisaul_2018, title={Prenatal bisphenol A (BPA) exposure alters the transcriptome of the neonate rat amygdala in a sex-specific manner: a CLARITY-BPA consortium study}, volume={65}, ISSN={["1872-9711"]}, DOI={10.1016/j.neuro.2017.10.005}, abstractNote={Bisphenol A (BPA) is a widely recognized endocrine disruptor prevalent in many household items. Because experimental and epidemiological data suggest links between prenatal BPA exposure and altered affective behaviors in children, even at levels below the current US FDA No Observed Adverse Effect Level (NOAEL) of 5 mg/kg body weight (bw)/day, there is concern that early life exposure may alter neurodevelopment. The current study was conducted as part of the CLARITY-BPA (Consortium Linking Academic and Regulatory Insights on BPA Toxicity) program and examined the full amygdalar transcriptome on postnatal day (PND) 1, with the hypothesis that prenatal BPA exposure would alter the expression of genes and pathways fundamental to sex-specific affective behaviors. NCTR Sprague-Dawley dams were gavaged from gestational day 6 until parturition with BPA (2.5, 25, 250, 2500, or 25000 μg/kg bw/day), a reference estrogen (0.05 or 0.5 μg ethinyl estradiol (EE2)/kg bw/day), or vehicle. PND 1 amygdalae were microdissected and gene expression was assessed with qRT-PCR (all exposure groups) and RNAseq (vehicle, 25 and 250 μg BPA, and 0.5 μg EE2 groups only). Our results demonstrate that that prenatal BPA exposure can disrupt the transcriptome of the neonate amygdala, at doses below the FDA NOAEL, in a sex-specific manner and indicate that the female amygdala may be more sensitive to BPA exposure during fetal development. We also provide additional evidence that developmental BPA exposure can interfere with estrogen, oxytocin, and vasopressin signaling pathways in the developing brain and alter signaling pathways critical for synaptic organization and transmission.}, journal={NEUROTOXICOLOGY}, author={Arambula, Sheryl E. and Jima, Dereje and Patisaul, Heather B.}, year={2018}, month={Mar}, pages={207–220} }
 @article{baldwin_phillips_horman_arambula_rebuli_stapleton_patisaul_2017, title={Sex Specific Placental Accumulation and Behavioral Effects of Developmental Firemaster 550 Exposure in Wistar Rats}, volume={7}, ISSN={["2045-2322"]}, DOI={10.1038/s41598-017-07216-6}, abstractNote={AbstractFiremaster® 550 (FM 550) is a commercial flame retardant mixture of brominated and organophosphate compounds applied to polyurethane foam used in furniture and baby products. Due to widespread human exposure, and structural similarities with known endocrine disruptors, concerns have been raised regarding possible toxicity. We previously reported evidence of sex specific behavioral effects in rats resulting from developmental exposure. The present study expands upon this prior finding by testing for a greater range of behavioral effects, and measuring the accumulation of FM 550 compounds in placental tissue. Wistar rat dams were orally exposed to FM 550 during gestation (0, 300 or 1000 µg/day; GD 9 – 18) for placental measurements or perinatally (0, 100, 300 or 1000 µg/day; GD 9 – PND 21) to assess activity and anxiety-like behaviors. Placental accumulation was dose dependent, and in some cases sex specific, with the brominated components reaching the highest levels. Behavioral changes were predominantly associated with a loss or reversal of sex differences in activity and anxiety-like behaviors. These findings demonstrate that environmental chemicals may sex-dependently accumulate in the placenta. That sex-biased exposure might translate to sex-specific adverse outcomes such as behavioral deficits is a possibility that merits further investigation.}, journal={SCIENTIFIC REPORTS}, author={Baldwin, Kylie R. and Phillips, Allison L. and Horman, Brian and Arambula, Sheryl E. and Rebuli, Meghan E. and Stapleton, Heather M. and Patisaul, Heather B.}, year={2017}, month={Aug} }
 @article{patisaul_2016, title={Endocrine disruption by dietary phyto-oestrogens: impact on dimorphic sexual systems and behaviours}, volume={76}, ISSN={0029-6651 1475-2719}, url={http://dx.doi.org/10.1017/s0029665116000677}, DOI={10.1017/s0029665116000677}, abstractNote={A wide range of health benefits have been ascribed to soya intake including a lowered risk of osteoporosis, heart disease, breast cancer, and menopausal symptoms. Because it is a hormonally active diet, however, soya can also be endocrine disrupting, suggesting that intake has the potential to cause adverse health effects in certain circumstances, particularly when exposure occurs during development. Consequently, the question of whether or not soya phyto-oestrogens are beneficial or harmful to human health is neither straightforward nor universally applicable to all groups. Possible benefits and risks depend on age, health status, and even the presence or absence of specific gut microflora. As global consumption increases, greater awareness and consideration of the endocrine-disrupting properties of soya by nutrition specialists and other health practitioners is needed. Consumption by infants and small children is of particular concern because their hormone-sensitive organs, including the brain and reproductive system, are still undergoing sexual differentiation and maturation. Thus, their susceptibility to the endocrine-disrupting activities of soya phyto-oestrogens may be especially high. As oestrogen receptor partial agonists with molecular and cellular properties similar to anthropogenic endocrine disruptors such as bisphenol A, the soya phyto-oestrogens provide an interesting model for how attitudes about what is ‘synthetic’ v. what is ‘natural,’ shapes understanding and perception of what it means for a compound to be endocrine disrupting and/or potentially harmful. This review describes the endocrine-disrupting properties of soya phyto-oestrogens with a focus on neuroendocrine development and behaviour.}, number={2}, journal={Proceedings of the Nutrition Society}, publisher={Cambridge University Press (CUP)}, author={Patisaul, Heather B.}, year={2016}, month={Jul}, pages={130–144} }
 @article{arambula_belcher_planchart_turner_patisaul_2016, title={Impact of Low Dose Oral Exposure to Bisphenol A (BPA) on the Neonatal Rat Hypothalamic and Hippocampal Transcriptome: A CLARITY-BPA Consortium Study}, volume={157}, ISSN={0013-7227 1945-7170}, url={http://dx.doi.org/10.1210/en.2016-1339}, DOI={10.1210/en.2016-1339}, abstractNote={Bisphenol A (BPA) is an endocrine disrupting, high volume production chemical found in a variety of products. Evidence of prenatal exposure has raised concerns that developmental BPA may disrupt sex-specific brain organization and, consequently, induce lasting changes on neurophysiology and behavior. We and others have shown that exposure to BPA at doses below the no-observed-adverse-effect level can disrupt the sex-specific expression of estrogen-responsive genes in the neonatal rat brain including estrogen receptors (ERs). The present studies, conducted as part of the Consortium Linking Academic and Regulatory Insights of BPA Toxicity program, expanded this work by examining the hippocampal and hypothalamic transcriptome on postnatal day 1 with the hypothesis that genes sensitive to estrogen and/or sexually dimorphic in expression would be altered by prenatal BPA exposure. NCTR Sprague-Dawley dams were gavaged from gestational day 6 until parturition with BPA (0-, 2.5-, 25-, 250-, 2500-, or 25 000-μg/kg body weight [bw]/d). Ethinyl estradiol was used as a reference estrogen (0.05- or 0.5-μg/kg bw/d). Postnatal day 1 brains were microdissected and gene expression was assessed with RNA-sequencing (0-, 2.5-, and 2500-μg/kg bw BPA groups only) and/or quantitative real-time PCR (all exposure groups). BPA-related transcriptional changes were mainly confined to the hypothalamus. Consistent with prior observations, BPA induced sex-specific effects on hypothalamic ERα and ERβ (Esr1 and Esr2) expression and hippocampal and hypothalamic oxytocin (Oxt) expression. These data demonstrate prenatal BPA exposure, even at doses below the current no-observed-adverse-effect level, can alter gene expression in the developing brain.}, number={10}, journal={Endocrinology}, publisher={The Endocrine Society}, author={Arambula, Sheryl E. and Belcher, Scott M. and Planchart, Antonio and Turner, Stephen D. and Patisaul, Heather B.}, year={2016}, month={Aug}, pages={3856–3872} }
 @article{hicks_sullivan_cao_sluzas_rebuli_patisaul_2016, title={Interaction of bisphenol A (BPA) and soy phytoestrogens on sexually dimorphic sociosexual behaviors in male and female rats}, volume={84}, ISSN={["1095-6867"]}, DOI={10.1016/j.yhbeh.2016.06.010}, abstractNote={Concerns have been raised regarding the potential for endocrine disrupting compounds (EDCs) to alter brain development and behavior. Developmental exposure to bisphenol A (BPA), a ubiquitous EDC, has been linked to altered sociosexual and mood-related behaviors in various animal models and children but effects are inconsistent across laboratories and animal models creating confusion about potential risk in humans. Exposure to endocrine active diets, such as soy, which is rich in phytoestrogens, may contribute to this variability. Here, we tested the individual and combined effects of low dose oral BPA and soy diet or the individual isoflavone genistein (GEN; administered as the aglycone genistin (GIN)) on rat sociosexual behaviors with the hypothesis that soy would obfuscate any BPA-related effects. Social and activity levels were unchanged by developmental exposure to BPA but soy diet had sex specific effects including suppressed novelty preference, and open field exploration in females. The data presented here reinforce that environmental factors, including anthropogenic chemical exposure and hormone active diets, can shape complex behaviors and even reverse expected sex differences.}, journal={HORMONES AND BEHAVIOR}, author={Hicks, Kimani D. and Sullivan, Alana W. and Cao, Jinyan and Sluzas, Emily and Rebuli, Meghan and Patisaul, Heather B.}, year={2016}, month={Aug}, pages={121–126} }
 @article{rebuli_gibson_rhodes_cushing_patisaul_2016, title={Sex differences in microglial colonization and vulnerabilities to endocrine disruption in the social brain}, volume={238}, ISSN={["1095-6840"]}, DOI={10.1016/j.ygcen.2016.04.018}, abstractNote={During development, microglia, the resident immune cells of the brain, play an important role in synaptic organization. Microglial colonization of the developing brain is sexually dimorphic in some regions, including nuclei critical for the coordination of social behavior, suggesting steroid hormones have an influencing role, particularly estrogen. By extension, microglial colonization may be vulnerable to endocrine disruption. Concerns have been raised regarding the potential for endocrine disrupting compounds (EDCs) to alter brain development and behavior. Developmental exposure to Bisphenol A (BPA), a ubiquitous EDC, has been associated with altered sociosexual and mood-related behaviors in various animal models and children. Through a comparison of the promiscuous Wistar rat (Rattus norvegicus) and the socially monogamous prairie vole (Microtus ochrogaster), we are the first to observe that developmental exposure to the synthetic estrogen ethinyl estradiol (EE) or BPA alters the sex-specific colonization of the hippocampus and amygdala by microglia.}, journal={GENERAL AND COMPARATIVE ENDOCRINOLOGY}, author={Rebuli, Meghan E. and Gibson, Paul and Rhodes, Cassie L. and Cushing, Bruce S. and Patisaul, Heather B.}, year={2016}, month={Nov}, pages={39–46} }
 @article{smith_lee_dausch_horman_patisaul_mccarty_sombers_2017, title={Simultaneous Voltammetric Measurements of Glucose and Dopamine Demonstrate the Coupling of Glucose Availability with Increased Metabolic Demand in the Rat Striatum}, volume={8}, ISSN={1948-7193 1948-7193}, url={http://dx.doi.org/10.1021/acschemneuro.6b00363}, DOI={10.1021/acschemneuro.6b00363}, abstractNote={Cerebral blood flow ensures delivery of nutrients, such as glucose, to brain sites with increased metabolic demand. However, little is known about rapid glucose dynamics at discrete locations during neuronal activation in vivo. Acute exposure to many substances of abuse elicits dopamine release and neuronal activation in the striatum; however, the concomitant changes in striatal glucose remain largely unknown. Recent developments have combined fast-scan cyclic voltammetry with glucose oxidase enzyme modified carbon-fiber microelectrodes to enable the measurement of glucose dynamics with subsecond temporal resolution in the mammalian brain. This work evaluates several waveforms to enable the first simultaneous detection of endogenous glucose and dopamine at single recording sites. These molecules, one electroactive and one nonelectroactive, were found to fluctuate in the dorsal striatum in response to electrical stimulation of the midbrain and systemic infusion of cocaine/raclopride. The data reveal the second-by-second dynamics of these species in a striatal microenvironment, and directly demonstrate the coupling of glucose availability with increased metabolic demand. This work provides a foundation that will enable detailed investigation of local mechanisms that regulate the coupling of cerebral blood flow with metabolic demand under normal conditions, and in animal studies of drug abuse and addiction.}, number={2}, journal={ACS Chemical Neuroscience}, publisher={American Chemical Society (ACS)}, author={Smith, Samantha K. and Lee, Christie A. and Dausch, Matthew E. and Horman, Brian M. and Patisaul, Heather B. and McCarty, Gregory S. and Sombers, Leslie A.}, year={2017}, month={Jan}, pages={272–280} }
 @article{phillips_chen_rock_horman_patisaul_stapleton_2016, title={Transplacental and Lactational Transfer of Firemaster (R) 550 Components in Dosed Wistar Rats}, volume={153}, ISSN={["1096-0929"]}, DOI={10.1093/toxsci/kfw122}, abstractNote={UNLABELLED
Firemaster® 550 (FM 550) is a commercial mixture of organophosphate and brominated flame retardants currently in use as a replacement for pentaBDE. Its organophosphate components include triphenyl phosphate (TPHP) and a suite of isopropylated triarylphosphate isomers (ITPs); its brominated components include 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis (2-ethylhexyl)-2,3,4,5-tetrabromophthalate (BEH-TEBP). Taken together, these chemicals have been shown to be endocrine disrupting and potentially toxic, and human exposure to them is widespread. In this study, maternal transfer of FM 550 components, and in some cases their metabolites, was investigated in dosed Wistar rats. Gestational and lactational transfer were examined separately, with dams orally exposed to 300 or 1000 µg of FM 550 for 10 consecutive days during gestation (gestational day [GD] 9-18) or lactation (postnatal day [PND] 3-12). Levels of parent compounds were measured in fetus and whole pup tissue homogenates, and in dam and pup serum, and several metabolites were measured in dam and pup urine. EH-TBB body burdens resulting from lactational transfer were approximately 200- to 300-fold higher than those resulting from placental transfer, whereas low levels of BEH-TEBP were transferred during both lactation and gestation. TPHP and ITPs were rapidly metabolized by the dams and were not detected in whole tissue homogenates. However, diphenyl phosphate (DPHP) and mono-isopropylphenyl phenyl phosphate (ip-PPP) were detected in urine from the dosed animals. This study is the first to confirm ip-PPP as a urinary metabolite of ITPs and establish a pharmacokinetic profile of FM 550 in a mammalian model.


KEY WORDS
Firemaster 550 ;: lactational transfer ;: gestational transfer; metabolites; rodent.}, number={2}, journal={TOXICOLOGICAL SCIENCES}, author={Phillips, Allison L. and Chen, Albert and Rock, Kylie D. and Horman, Brian and Patisaul, Heather B. and Stapleton, Heather M.}, year={2016}, month={Oct}, pages={246–257} }
 @article{rebuli_patisaul_2016, title={Assessment of sex specific endocrine disrupting effects in the prenatal and pre-pubertal rodent brain}, volume={160}, ISSN={["0960-0760"]}, DOI={10.1016/j.jsbmb.2015.08.021}, abstractNote={Brain sex differences are found in nearly every region of the brain and fundamental to sexually dimorphic behaviors as well as disorders of the brain and behavior. These differences are organized during gestation and early adolescence and detectable prior to puberty. Endocrine disrupting compounds (EDCs) interfere with hormone action and are thus prenatal exposure is hypothesized to disrupt the formation of sex differences, and contribute to the increased prevalence of pediatric neuropsychiatric disorders that present with a sex bias.Available evidence for the ability of EDCs to impact the emergence of brain sex differences in the rodent brain was reviewed here, with a focus on effects detected at or before puberty.The peer-reviewed literature was searched using PubMed, and all relevant papers published by January 31, 2015 were incorporated. Endpoints of interest included molecular cellular and neuroanatomical effects. Studies on behavioral endpoints were not included because numerous reviews of that literature are available.The hypothalamus was found to be particularly affected by estrogenic EDCs in a sex, time, and exposure dependent manner. The hippocampus also appears vulnerable to endocrine disruption by BPA and PCBs although there is little evidence from the pre-pubertal literature to make any conclusions about sex-specific effects. Gestational EDC exposure can alter fetal neurogenesis and gene expression throughout the brain including the cortex and cerebellum. The available literature primarily focuses on a few, well characterized EDCs, but little data is available for emerging contaminants.The developmental EDC exposure literature demonstrates evidence of altered neurodevelopment as early as fetal life, with sex specific effects observed throughout the brain even before puberty.}, journal={JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY}, author={Rebuli, Meghan E. and Patisaul, Heather B.}, year={2016}, month={Jun}, pages={148–159} }
 @article{veiga-lopez_pennathur_kannan_patisaul_dolinoy_zeng_padmanabhan_2015, title={Impact of Gestational Bisphenol A on Oxidative Stress and Free Fatty Acids: Human Association and Interspecies Animal Testing Studies}, volume={156}, ISSN={["1945-7170"]}, DOI={10.1210/en.2014-1863}, abstractNote={AbstractBisphenol A (BPA) is a high production volume chemical and an endocrine disruptor. Developmental exposures to BPA have been linked to adult metabolic pathologies, but the pathways through which these disruptions occur remain unknown. This is a comprehensive interspecies association vs causal study to evaluate risks posed by prenatal BPA exposure and to facilitate discovery of biomarkers of relevance to BPA toxicity. Samples from human pregnancies during the first trimester and at term, as well as fetal and/or adult samples from prenatally BPA-treated sheep, rats, and mice, were collected to assess the impact of BPA on free fatty acid and oxidative stress dynamics. Mothers exposed to higher BPA during early to midpregnancy and their matching term cord samples displayed increased 3-nitrotyrosine (NY), a marker of nitrosative stress. Maternal samples had increased palmitic acid, which was positively correlated with NY. Sheep fetuses and adult sheep and rats prenatally exposed to a human-relevant exposure dose of BPA showed increased systemic nitrosative stress. The strongest effect of BPA on circulating free fatty acids was observed in adult mice in the absence of increased oxidative stress. This is the first multispecies study that combines human association and animal causal studies assessing the risk posed by prenatal BPA exposure to metabolic health. This study provides evidence of the induction of nitrosative stress by prenatal BPA in both the mother and fetus at time of birth and is thus supportive of the use of maternal NY as a biomarker for offspring health.}, number={3}, journal={ENDOCRINOLOGY}, author={Veiga-Lopez, Almudena and Pennathur, Subramaniam and Kannan, Kurunthachalam and Patisaul, Heather B. and Dolinoy, Dana C. and Zeng, Lixia and Padmanabhan, Vasantha}, year={2015}, month={Mar}, pages={911–922} }
 @article{rebuli_camacho_adonay_reif_aylor_patisaul_2015, title={Impact of Low-Dose Oral Exposure to Bisphenol A (BPA) on Juvenile and Adult Rat Exploratory and Anxiety Behavior: A CLARITY-BPA Consortium Study}, volume={148}, ISSN={["1096-0929"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84952932385&partnerID=MN8TOARS}, DOI={10.1093/toxsci/kfv163}, abstractNote={Bisphenol A (BPA) is a high volume production chemical and has been identified as an endocrine disruptor, prompting concern that developmental exposure could impact brain development and behavior. Rodent and human studies suggest that early life BPA exposure may result in an anxious, hyperactive phenotype but results are conflicting and data from studies using multiple doses below the no-observed-adverse-effect level are limited. To address this, the present studies were conducted as part of the CLARITY-BPA (Consortium Linking Academic and Regulatory Insights on BPA Toxicity) program. The impact of perinatal BPA exposure (2.5, 25, or 2500 µg/kg body weight (bw)/day) on behaviors related to anxiety and exploratory activity was assessed in juvenile (prepubertal) and adult NCTR Sprague-Dawley rats of both sexes. Ethinyl estradiol (0.5 µg/kg bw/day) was used as a reference estrogen. Exposure spanned gestation and lactation with dams gavaged from gestational day 6 until birth and then the offspring gavaged directly through weaning (n = 12/sex/group). Behavioral assessments included open field, elevated plus maze, and zero maze. Anticipated sex differences in behavior were statistically identified or suggested in most cases. No consistent effects of BPA were observed for any endpoint, in either sex, at either age compared to vehicle controls; however, significant differences between BPA-exposed and ethinyl estradiol-exposed groups were identified for some endpoints. Limitations of this study are discussed and include suboptimal statistical power and low concordance across behavioral tasks. These data do not indicate BPA-related effects on anxiety or exploratory activity in these developmentally exposed rats.}, number={2}, journal={TOXICOLOGICAL SCIENCES}, author={Rebuli, Meghan E. and Camacho, Luisa and Adonay, Maria E. and Reif, David M. and Aylor, David L. and Patisaul, Heather B.}, year={2015}, month={Dec}, pages={341–354} }
 @article{cao_echelberger_liu_sluzas_mccaffrey_buckley_patisaul_2015, title={Soy but not bisphenol A (BPA) or the phytoestrogen genistin alters developmental weight gain and food intake in pregnant rats and their offspring}, volume={58}, ISSN={["0890-6238"]}, DOI={10.1016/j.reprotox.2015.07.077}, abstractNote={Endocrine disrupting compounds (EDCs) are hypothesized to promote obesity and early puberty but their interactive effects with hormonally active diets are poorly understood. Here we assessed individual and combinatorial effects of soy diet or the isoflavone genistein (GEN; administered as the aglycone genistin GIN) with bisphenol A (BPA) on body weight, ingestive behavior and female puberal onset in Wistar rats. Soy-fed dams gained less weight during pregnancy and, although they consumed more than dams on a soy-free diet during lactation, did not become heavier. Their offspring (both sexes), however, became significantly heavier (more pronounced in males) pre-weaning. Soy also enhanced food intake and accelerated female pubertal onset in the offspring. Notably, pubertal onset was also advanced in females placed on soy diet at weaning. Males exposed to BPA plus soy diet, but not BPA alone, had lighter testes. BPA had no independent effects.}, journal={REPRODUCTIVE TOXICOLOGY}, author={Cao, Jinyan and Echelberger, Roger and Liu, Min and Sluzas, Emily and McCaffrey, Katherine and Buckley, Brian and Patisaul, Heather B.}, year={2015}, month={Dec}, pages={282–294} }
 @article{sullivan_beach_stetzik_perry_alyssa s. d'addezio_cushing_patisaul_2014, title={A Novel Model for Neuroendocrine Toxicology: Neurobehavioral Effects of BPA Exposure in a Prosocial Species, the Prairie Vole (Microtus ochrogaster)}, volume={155}, ISSN={["1945-7170"]}, DOI={10.1210/en.2014-1379}, abstractNote={Abstract
               Impacts on brain and behavior have been reported in laboratory rodents after developmental exposure to bisphenol A (BPA), raising concerns about possible human effects. Epidemiological data suggest links between prenatal BPA exposure and altered affective behaviors in children, but potential mechanisms are unclear. Disruption of mesolimbic oxytocin (OT)/vasopressin (AVP) pathways have been proposed, but supporting evidence is minimal. To address these data gaps, we employed a novel animal model for neuroendocrine toxicology: the prairie vole (Microtus ochrogaster), which are more prosocial than lab rats or mice. Male and female prairie vole pups were orally exposed to 5-μg/kg body weight (bw)/d, 50-μg/kg bw/d, or 50-mg/kg bw/d BPA or vehicle over postnatal days 8–14. Subjects were tested as juveniles in open field and novel social tests and for partner preference as adults. Brains were then collected and assessed for immunoreactive (ir) tyrosine hydroxylase (TH) (a dopamine marker) neurons in the principal bed nucleus of the stria terminalis (pBNST) and TH-ir, OT-ir, and AVP-ir neurons in the paraventricular nucleus of the hypothalamus (PVN). Female open field activity indicated hyperactivity at the lowest dose and anxiety at the highest dose. Effects on social interactions were also observed, and partner preference formation was mildly inhibited at all dose levels. BPA masculinized principal bed nucleus of the stria terminalis TH-ir neuron numbers in females. Additionally, 50-mg/kg bw BPA-exposed females had more AVP-ir neurons in the anterior PVN and fewer OT-ir neurons in the posterior PVN. At the 2 lowest doses, BPA eliminated sex differences in PVN TH-ir neuron numbers and reversed this sex difference at the highest dose. Minimal behavioral effects were observed in BPA-exposed males. These data support the hypothesis that BPA alters affective behaviors, potentially via disruption of OT/AVP pathways.}, number={10}, journal={ENDOCRINOLOGY}, author={Sullivan, Alana W. and Beach, Elsworth C. and Stetzik, Lucas A. and Perry, Amy and Alyssa S. D'Addezio and Cushing, Bruce S. and Patisaul, Heather B.}, year={2014}, month={Oct}, pages={3867–3881} }
 @article{belcher_cookman_patisaul_stapleton_2014, title={In vitro assessment of human nuclear hormone receptor activity and cytotoxicity of the flame retardant mixture FM 550 and its triarylphosphate and brominated components}, volume={228}, ISSN={0378-4274}, url={http://dx.doi.org/10.1016/J.TOXLET.2014.04.017}, DOI={10.1016/j.toxlet.2014.04.017}, abstractNote={Firemaster® 550 (FM 550) is a mixture of brominated and triarylphosphate flame retardants used in polyurethane foam-based products. The primary components are also used in numerous other applications and are thus common household and industrial contaminants. Our previous animal studies suggested that FM 550 exposure may alter metabolism and cause weight gain. Employing human nuclear receptor (NR) luciferase reporter assays, the goal of this study was to evaluate the agonist actions of FM 550 and its constituent compounds at NRs with known roles in establishing or regulating energy balance. FM 550 was found to have significant agonist activity only at the master regulator of adipocyte differentiation PPARγ. As a result, the concentration response relationships and relative activities of FM 550 at PPARγ were investigated in more detail with the contribution of each chemical component defined and compared to the activities of the prototypical PPARγ environmental ligands triphenyltin and tributyltin. The resulting data indicated that the primary metabolic disruptive effects of FM 550 were likely mediated by the activity of the triarylphosphates at PPARγ, and have identified TPP as a candidate metabolic disruptor that also acts as a cytotoxicant.}, number={2}, journal={Toxicology Letters}, publisher={Elsevier BV}, author={Belcher, Scott M. and Cookman, Clifford J. and Patisaul, Heather B. and Stapleton, Heather M.}, year={2014}, month={Jul}, pages={93–102} }
 @article{rebuli_cao_sluzas_delclos_camacho_lewis_vanlandingham_patisaul_2014, title={Investigation of the Effects of Subchronic Low Dose Oral Exposure to Bisphenol A (BPA) and Ethinyl Estradiol (EE) on Estrogen Receptor Expression in the Juvenile and Adult Female Rat Hypothalamus}, volume={140}, ISSN={["1096-0929"]}, DOI={10.1093/toxsci/kfu074}, abstractNote={Concerns have been raised regarding the long-term impacts of early life exposure to the ubiquitous environmental contaminant bisphenol A (BPA) on brain organization. Because BPA has been reported to affect estrogen signaling, and steroid hormones play a critical role in brain sexual differentiation, there is also concern that BPA exposure could alter neural sex differences. Here, we examine the impact of subchronic exposure from gestation to adulthood to oral doses of BPA below the current no-observed-adverse-effect level (NOAEL) of 5 mg/kg body weight (bw)/day on estrogen receptor (ESR) expression in sexually dimorphic brain regions of prepubertal and adult female rats. The dams were gavaged daily with vehicle (0.3% carboxymethylcellulose), 2.5, 25, 260, or 2700 μg BPA/kg bw/day, or 0.5 or 5.0 μg ethinyl estradiol (EE)/kg bw/day from gestational day 6 until labor began. Offspring were then gavaged directly from the day after birth until the day before scheduled sacrifice on postnatal days 21 or 90. Using in situ hybridization, one or more BPA doses produced significant decreases in Esr1 expression in the juvenile female rat anteroventral periventricular nucleus (AVPV) of the hypothalamus and significant decreases in Esr2 expression in the adult female rat AVPV and medial preoptic area (MPOA), relative to vehicle controls. BPA did not simply reproduce EE effects, indicating that BPA is not acting solely as an estrogen mimic. The possible consequences of long-term changes in hypothalamic ESR expression resulting from subchronic low dose BPA exposure on neuroendocrine effects are discussed and being addressed in ongoing, related work.}, number={1}, journal={TOXICOLOGICAL SCIENCES}, author={Rebuli, Meghan E. and Cao, Jinyan and Sluzas, Emily and Delclos, K. Barry and Camacho, Luisa and Lewis, Sherry M. and Vanlandingham, Michelle M. and Patisaul, Heather B.}, year={2014}, month={Jul}, pages={190–203} }
 @article{patisaul_mabrey_adewale_sullivan_2014, title={Soy but not bisphenol A (BPA) induces hallmarks of polycystic ovary syndrome (PCOS) and related metabolic co-morbidities in rats}, volume={49}, ISSN={["0890-6238"]}, DOI={10.1016/j.reprotox.2014.09.003}, abstractNote={Polycystic ovarian syndrome (PCOS) is the most common female endocrine disorder with a prevalence as high as 8–15% depending on ethnicity and the diagnostic criteria employed. The basic pathophysiology and mode of inheritance remain unclear, but environmental factors such as diet, stress and chemical exposures are thought to be contributory. Developmental exposure to endocrine disrupting compounds (EDCs) have been hypothesized to exacerbate risk, in part because PCOS hallmarks and associated metabolic co-morbidities can be reliably induced in animal models by perinatal androgen exposure. Here we show that lifetime exposure to a soy diet, containing endocrine active phytoestrogens, but not developmental exposure (gestational day 6–lactational day 40) to the endocrine disrupting monomer bisphenol A (BPA), can induce key features of PCOS in the rat; results which support the hypothesis that hormonally active diets may contribute to risk when consumed throughout gestation and post-natal life.}, journal={REPRODUCTIVE TOXICOLOGY}, author={Patisaul, Heather B. and Mabrey, Natalie and Adewale, Heather B. and Sullivan, Alana W.}, year={2014}, month={Nov}, pages={209–218} }
 @article{filer_patisaul_schug_reif_thayer_2014, title={Test driving ToxCast: endocrine profiling for 1858 chemicals included in phase II}, volume={19}, ISSN={["1471-4973"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84908151070&partnerID=MN8TOARS}, DOI={10.1016/j.coph.2014.09.021}, abstractNote={Identifying chemicals, beyond those already implicated, to test for potential endocrine disruption is a challenge and high throughput approaches have emerged as a potential tool for this type of screening. This review focused the Environmental Protection Agency's (EPA) ToxCast™ high throughput in vitro screening (HTS) program. Utility for identifying compounds was assessed and reviewed by using it to run the recently expanded chemical library (from 309 compounds to 1858) through the ToxPi™ prioritization scheme for endocrine disruption. The analysis included metabolic and neuroendocrine targets. This investigative approach simultaneously assessed the utility of ToxCast, and helped identify novel chemicals which may have endocrine activity. Results from this exercise suggest the spectrum of environmental chemicals with potential endocrine activity is much broader than indicated, and that some aspects of endocrine disruption are not fully covered in ToxCast.}, journal={CURRENT OPINION IN PHARMACOLOGY}, author={Filer, Dayne and Patisaul, Heather B. and Schug, Thaddeus and Reif, David and Thayer, Kristina}, year={2014}, month={Dec}, pages={145–152} }
 @article{hoffman_fang_horman_patisaul_garantziotis_birnbaum_stapleton_2014, title={Urinary Tetrabromobenzoic Acid (TBBA) as a Biomarker of Exposure to the Flame Retardant Mixture Firemaster
            
              ®
            
            550}, volume={122}, ISSN={0091-6765 1552-9924}, url={http://dx.doi.org/10.1289/ehp.1308028}, DOI={10.1289/ehp.1308028}, abstractNote={Background: Firemaster® 550 (FM550) is commonly added to residential furniture to reduce its flammability. Recent toxicological evidence suggests that FM550 may be endocrine disrupting and obesogenic.Objectives: Our objectives were to develop methods to assess exposure to FM550 in human populations and to identify potential routes of exposure.Methods: Using mass spectrometry methods, we developed a method to measure 2,3,4,5-tetrabromobenzoic acid (TBBA), a urinary metabolite of the major brominated FM550 component 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB). The method was applied to a cohort of adult volunteers (n = 64). Participants completed questionnaires, provided urine and handwipe samples, and collected dust samples from their homes. We measured TBB and the other major brominated FM550 component, bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), in paired dust and handwipe samples.Results: TBBA was detected in 72.4% of urine samples. Although TBBA is a rapidly formed metabolite, analyses indicated moderate temporal reliability (interclass correlation coefficient = 0.56; 95% confidence interval: 0.46, 0.66). TBB and TBPH were detected frequently in dust samples [geometric mean (GM) = 315.1 and 364.7 ng/g, respectively] and in handwipes (GM = 31.4 and 23.4 ng, respectively). Levels of TBB and TBPH in dust were positively correlated with levels in handwipes. In addition, levels of TBB in handwipes were positively correlated with urinary TBBA. Results suggest frequent hand washing may reduce the mass of TBB on participants’ hands and reduce urinary TBBA levels.Conclusions: Cumulatively, our data indicate that exposures to FM550 are widespread and that the home environment may be an important source of exposure. Urinary TBBA provides a potentially useful biomarker of FM550 exposure for epidemiologic studies.Citation: Hoffman K, Fang M, Horman B, Patisaul HB, Garantziotis S, Birnbaum LS, Stapleton HM. 2014. Urinary tetrabromobenzoic acid (TBBA) as a biomarker of exposure to the flame retardant mixture Firemaster® 550. Environ Health Perspect 122:963–969; http://dx.doi.org/10.1289/ehp.1308028}, number={9}, journal={Environmental Health Perspectives}, publisher={Environmental Health Perspectives}, author={Hoffman, Kate and Fang, Mingliang and Horman, Brian and Patisaul, Heather B. and Garantziotis, Stavros and Birnbaum, Linda S. and Stapleton, Heather M.}, year={2014}, month={Sep}, pages={963–969} }
 @article{yeo_patisaul_liedtke_2013, title={Decoding the language of epigenetics during neural development is key for understanding development as well as developmental neurotoxicity}, volume={8}, ISSN={["1559-2308"]}, DOI={10.4161/epi.26406}, abstractNote={Neural development is a delicate process that can be disrupted by pollution that exerts detrimental impact on neural signaling. This commentary highlights recent discoveries in the arena of research at the interface of environmental toxicology and developmental neuroscience relating to toxicity mechanisms of bisphenol A (BPA), a ubiquitous chemical used in manufacturing of plastics and epoxy resins that is known to bind to and interfere with estrogen receptors, estrogen-receptor-related receptors and other receptors for gonadal steroids. It was recently observed that BPA disrupts the perinatal chloride shift, a key neurodevelopmental mechanism that brings down neuronal chloride from ~100 mM to ~20 mM within weeks. The chloride shift happens in all central nervous systems of vertebrates around parturition. High neuronal chloride supports neuron precursors’ migrations, low neuronal chloride is the prerequisite for inhibitory action of neurotransmitters GABA and glycine, and thus an absolute requisite for normal functioning of the mature CNS. One critical contributor to the neuronal chloride shift is the concomitant upregulation of expression of the chloride-extruding transporter molecule, KCC2. We highlight recent findings including our discovery that BPA disrupts the chloride shift in a sex-specific manner by recruiting epigenetics mechanisms. These could be relevant for childhood neuropsychiatric disorders as well as for liability to develop chronic neuropsychiatric diseases later in life.}, number={11}, journal={EPIGENETICS}, author={Yeo, Michele and Patisaul, Heather and Liedtke, Wolfgang}, year={2013}, month={Nov}, pages={1128–1132} }
 @article{schug_abagyan_blumberg_collins_crews_defur_dickerson_edwards_gore_guillette_et al._2013, title={Designing endocrine disruption out of the next generation of chemicals}, volume={15}, number={1}, journal={Green Chemistry}, author={Schug, T. T. and Abagyan, R. and Blumberg, B. and Collins, T. J. and Crews, D. and DeFur, P. L. and Dickerson, S. M. and Edwards, T. M. and Gore, A. C. and Guillette, L. J. and et al.}, year={2013}, pages={181–198} }
 @article{patisaul_2013, title={Effects of environmental endocrine disruptors and phytoestrogens on the Kisspeptin system}, volume={784}, journal={Kisspeptin signaling in reproductive biology}, author={Patisaul, H. B.}, year={2013}, pages={455–479} }
 @article{cao_rebuli_rogers_todd_leyrer_ferguson_patisaul_2013, title={Prenatal Bisphenol A Exposure Alters Sex-Specific Estrogen Receptor Expression in the Neonatal Rat Hypothalamus and Amygdala}, volume={133}, ISSN={["1096-0929"]}, DOI={10.1093/toxsci/kft035}, abstractNote={Bisphenol A (BPA) exposure is ubiquitous, and in laboratory animals, early-life BPA exposure has been shown to alter sex-specific neural organization, neuroendocrine physiology, and behavior. The specific mechanisms underlying these brain-related outcomes, however, remain largely unknown, constraining the capacity to ascertain the potential human relevance of neural effects observed in animal models. In the perinatal rat brain, estrogen is masculinizing, suggesting that BPA-induced perturbation of estrogen receptor (ESR) expression may underpin later in-life neuroendocrine effects. We hypothesized that prenatal BPA exposure alters sex-specific ESR1 (ERα) and ESR2 (ERβ) expression in postnatal limbic nuclei. Sprague Dawley rats were mated and gavaged on gestational days (GDs) 6-21 with vehicle, 2.5 or 25 μg/kg bw/day BPA, or 5 or 10 μg/kg bw/day ethinyl estradiol. An additional group was restrained but not gavaged (naïve control). Offspring were sacrificed the day after birth to quantify ESR gene expression throughout the hypothalamus and amygdala by in situ hybridization. Relative to the vehicle group, significant effects of BPA were observed on ESR1 and ESR2 expression throughout the mediobasal hypothalamus and amygdala in both sexes. Significant differences in ESR expression were also observed in the mediobasal hypothalamus and amygdala of the naïve control group compared with the vehicle group, highlighting the potential for gavage to influence gene expression in the developing brain. These results indicate that ESR expression in the neonatal brain of both sexes can be altered by low-dose prenatal BPA exposure.}, number={1}, journal={TOXICOLOGICAL SCIENCES}, author={Cao, Jinyan and Rebuli, Meghan E. and Rogers, James and Todd, Karina L. and Leyrer, Stephanie M. and Ferguson, Sherry A. and Patisaul, Heather B.}, year={2013}, month={May}, pages={157–173} }
 @article{mccaffrey_jones_mabrey_weiss_swan_patisaul_2013, title={Sex specific impact of perinatal bisphenol A (BPA) exposure over a range of orally administered doses on rat hypothalamic sexual differentiation}, volume={36}, ISSN={["1872-9711"]}, DOI={10.1016/j.neuro.2013.03.001}, abstractNote={Bisphenol A (BPA) is a high volume production chemical used in polycarbonate plastics, epoxy resins, thermal paper receipts, and other household products. The neural effects of early life BPA exposure, particularly to low doses administered orally, remain unclear. Thus, to better characterize the dose range over which BPA alters sex specific neuroanatomy, we examined the impact of perinatal BPA exposure on two sexually dimorphic regions in the anterior hypothalamus, the sexually dimorphic nucleus of the preoptic area (SDN-POA) and the anterioventral periventricular (AVPV) nucleus. Both are sexually differentiated by estradiol and play a role in sex specific reproductive physiology and behavior. Long Evans rats were prenatally exposed to 10, 100, 1000, 10,000μg/kg bw/day BPA through daily, non-invasive oral administration of dosed-cookies to the dams. Offspring were reared to adulthood. Their brains were collected and immunolabeled for tyrosine hydroxylase (TH) in the AVPV and calbindin (CALB) in the SDN-POA. We observed decreased TH-ir cell numbers in the female AVPV across all exposure groups, an effect indicative of masculinization. In males, AVPV TH-ir cell numbers were significantly reduced in only the BPA 10 and BPA 10,000 groups. SDN-POA endpoints were unaltered in females but in males SDN-POA volume was significantly lower in all BPA exposure groups. CALB-ir was significantly lower in all but the BPA 1000 group. These effects are consistent with demasculinization. Collectively these data demonstrate that early life oral exposure to BPA at levels well below the current No Observed Adverse Effect Level (NOAEL) of 50mg/kg/day can alter sex specific hypothalamic morphology in the rat.}, journal={NEUROTOXICOLOGY}, author={McCaffrey, Katherine A. and Jones, Brian and Mabrey, Natalie and Weiss, Bernard and Swan, Shanna H. and Patisaul, Heather B.}, year={2013}, month={May}, pages={55–62} }
 @article{cao_joyner_mickens_leyrer_patisaul_2014, title={Sex-specific Esr2 mRNA expression in the rat hypothalamus and amygdala is altered by neonatal bisphenol A exposure}, volume={147}, ISSN={["1470-1626"]}, DOI={10.1530/rep-13-0501}, abstractNote={Perinatal life is a critical window for sexually dimorphic brain organization, and profoundly influenced by steroid hormones. Exposure to endocrine-disrupting compounds may disrupt this process, resulting in compromised reproductive physiology and behavior. To test the hypothesis that neonatal bisphenol A (BPA) exposure can alter sex-specific postnatalEsr2(Erβ) expression in brain regions fundamental to sociosexual behavior, we mappedEsr2mRNA levels in the principal nucleus of the bed nucleus of the stria terminalis (BNSTp), paraventricular nucleus (PVN), anterior portion of the medial amygdaloid nucleus (MeA), super optic nucleus, suprachiasmatic nucleus, and lateral habenula across postnatal days (PNDs) 0–19. Next, rat pups of both sexes were subcutaneously injected with 10 μg estradiol benzoate (EB), 50 μg/kg BPA (LBPA), or 50 mg/kg BPA (HBPA) over the first 3 days of life andEsr2levels were quantified in each region of interest (ROI) on PNDs 4 and 10. EB exposure decreasedEsr2signal in most female ROIs and in the male PVN. In the BNSTp,Esr2expression decreased in LBPA males and HBPA females on PND 10, thereby reversing the sex difference in expression. In the PVN,Esr2mRNA levels were elevated in LBPA females, also resulting in a reversal of sexually dimorphic expression. In the MeA, BPA decreasedEsr2expression on PND 4. Collectively, these data demonstrate that region- and sex-specificEsr2expression is vulnerable to neonatal BPA exposure in regions of the developing brain critical to sociosexual behavior in rat.}, number={4}, journal={REPRODUCTION}, author={Cao, Jinyan and Joyner, Linwood and Mickens, Jillian A. and Leyrer, Stephanie M. and Patisaul, Heather B.}, year={2014}, month={Apr}, pages={537–554} }
 @article{patisaul_roberts_mabrey_mccaffrey_gear_braun_belcher_stapleton_2012, title={Accumulation and Endocrine Disrupting Effects of the Flame Retardant Mixture Firemaster®550 in Rats: An Exploratory Assessment}, volume={27}, ISSN={1095-6670}, url={http://dx.doi.org/10.1002/jbt.21439}, DOI={10.1002/jbt.21439}, abstractNote={ABSTRACTFiremaster® 550 (FM 550), a fire‐retardant mixture used in foam‐based products, was recently identified as a common contaminant in household dust. The chemical structures of its principle components suggest they have endocrine disrupting activity, but nothing is known about their physiological effects at environmentally relevant exposure levels. The goal of this exploratory study was to evaluate accumulation, metabolism and endocrine disrupting effects of FM 550 in rats exposed to 100 or 1000 µg/day across gestation and lactation. FM 550 components accumulated in tissues of exposed dams and offspring and induced phenotypic hallmarks associated with metabolic syndrome in the offspring. Effects included increased serum thyroxine levels and reduced hepatic carboxylesterease activity in dams, and advanced female puberty, weight gain, male cardiac hypertrophy, and altered exploratory behaviors in offspring. Results of this study are the first to implicate FM 550 as an endocrine disruptor and an obesogen at environmentally relevant levels. #x000A9; 2012 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:124‐136, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.21439}, number={2}, journal={Journal of Biochemical and Molecular Toxicology}, publisher={Wiley}, author={Patisaul, Heather B. and Roberts, Simon C. and Mabrey, Natalie and McCaffrey, Katherine A. and Gear, Robin B. and Braun, Joe and Belcher, Scott M. and Stapleton, Heather M.}, year={2012}, month={Nov}, pages={124–136} }
 @article{patisaul_sullivan_radford_walker_adewale_winnik_coughlin_buckley_gore_2012, title={Anxiogenic Effects of Developmental Bisphenol A Exposure Are Associated with Gene Expression Changes in the Juvenile Rat Amygdala and Mitigated by Soy}, volume={7}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0043890}, abstractNote={Early life exposure to Bisphenol A (BPA), a component of polycarbonate plastics and epoxy resins, alters sociosexual behavior in numerous species including humans. The present study focused on the ontogeny of these behavioral effects beginning in adolescence and assessed the underlying molecular changes in the amygdala. We also explored the mitigating potential of a soy-rich diet on these endpoints. Wistar rats were exposed to BPA via drinking water (1 mg/L) from gestation through puberty, and reared on a soy-based or soy-free diet. A group exposed to ethinyl estradiol (50 µg/L) and a soy-free diet was used as a positive estrogenic control. Animals were tested as juveniles or adults for anxiety-like and exploratory behavior. Assessment of serum BPA and genistein (GEN), a soy phytoestrogen, confirmed that internal dose was within a human-relevant range. BPA induced anxiogenic behavior in juveniles and loss of sexual dimorphisms in adult exploratory behavior, but only in the animals reared on the soy-free diet. Expression analysis revealed a suite of genes, including a subset known to mediate sociosexual behavior, associated with BPA-induced juvenile anxiety. Notably, expression of estrogen receptor beta (Esr2) and two melanocortin receptors (Mc3r, Mc4r) were downregulated. Collectively, these results show that behavioral impacts of BPA can manifest during adolescence, but wane in adulthood, and may be mitigated by diet. These data also reveal that, because ERβ and melanocortin receptors are crucial to their function, oxytocin/vasopressin signaling pathways, which have previously been linked to human affective disorders, may underlie these behavioral outcomes.}, number={9}, journal={PLOS ONE}, author={Patisaul, Heather B. and Sullivan, Alana W. and Radford, Meghan E. and Walker, Deena M. and Adewale, Heather B. and Winnik, Bozena and Coughlin, Janis L. and Buckley, Brian and Gore, Andrea C.}, year={2012}, month={Sep} }
 @article{schug_abagyan_blumberg_collins_crews_defur_dickerson_edwards_gore_guillette_et al._2013, title={Designing endocrine disruption out of the next generation of chemicals}, volume={15}, ISSN={1463-9262 1463-9270}, url={http://dx.doi.org/10.1039/c2gc35055f}, DOI={10.1039/c2gc35055f}, abstractNote={A central goal of green chemistry is to avoid hazard in the design of new chemicals. This objective is best achieved when information about a chemical's potential hazardous effects is obtained as early in the design process as feasible. Endocrine disruption is a type of hazard that to date has been inadequately addressed by both industrial and regulatory science. To aid chemists in avoiding this hazard, we propose an endocrine disruption testing protocol for use by chemists in the design of new chemicals. The Tiered Protocol for Endocrine Disruption (TiPED) has been created under the oversight of a scientific advisory committee composed of leading representatives from both green chemistry and the environmental health sciences. TiPED is conceived as a tool for new chemical design, thus it starts with a chemist theoretically at "the drawing board." It consists of five testing tiers ranging from broad in silico evaluation up through specific cell- and whole organism-based assays. To be effective at detecting endocrine disruption, a testing protocol must be able to measure potential hormone-like or hormone-inhibiting effects of chemicals, as well as the many possible interactions and signaling sequellae such chemicals may have with cell-based receptors. Accordingly, we have designed this protocol to broadly interrogate the endocrine system. The proposed protocol will not detect all possible mechanisms of endocrine disruption, because scientific understanding of these phenomena is advancing rapidly. To ensure that the protocol remains current, we have established a plan for incorporating new assays into the protocol as the science advances. In this paper we present the principles that should guide the science of testing new chemicals for endocrine disruption, as well as principles by which to evaluate individual assays for applicability, and laboratories for reliability. In a 'proof-of-principle' test, we ran 6 endocrine disrupting chemicals (EDCs) that act via different endocrinological mechanisms through the protocol using published literature. Each was identified as endocrine active by one or more tiers. We believe that this voluntary testing protocol will be a dynamic tool to facilitate efficient and early identification of potentially problematic chemicals, while ultimately reducing the risks to public health.}, number={1}, journal={Green Chem.}, publisher={Royal Society of Chemistry (RSC)}, author={Schug, T. T. and Abagyan, R. and Blumberg, B. and Collins, T. J. and Crews, D. and DeFur, P. L. and Dickerson, S. M. and Edwards, T. M. and Gore, A. C. and Guillette, L. J. and et al.}, year={2013}, pages={181–198} }
 @article{losa-ward_todd_mccaffrey_tsutsui_patisaul_2012, title={Disrupted Organization of RFamide Pathways in the Hypothalamus Is Associated with Advanced Puberty in Female Rats Neonatally Exposed to Bisphenol A}, volume={87}, ISSN={["1529-7268"]}, DOI={10.1095/biolreprod.112.100826}, abstractNote={ABSTRACT Hypothalamic neurons, which produce the kisspeptin family of peptide hormones (Kp), are critical for initiating puberty and maintaining estrous cyclicity by stimulating gonadotropin-releasing hormone (GnRH) release. Conversely, RFamide-related peptide-3 (RFRP3) neurons inhibit GnRH activity. It has previously been shown that neonatal exposure to bisphenol A (BPA) can alter the timing of female pubertal onset and induce irregular estrous cycles or premature anestrus. Here we tested the hypothesis that disrupted ontogeny of RFamide signaling pathways may be a mechanism underlying advanced puberty. To test this, we used a transgenic strain of Wistar rats whose GnRH neurons express enhanced green fluorescent protein. Pups were exposed by daily subcutaneous injection to vehicle, 17beta-estradiol (E2), 50 μg/kg BPA, or 50 mg/kg BPA, from Postnatal Day (PND) 0 through PND 3, and then cohorts were euthanized on PNDs 17, 21, 24, 28, and 33 (5–8 animals per age per exposure; males were collected on PNDs 21 and 33). Vaginal opening was advanced by E2 and 50 μg/kg BPA. On PND 28, females exposed to E2 and 50 μg/kg BPA had decreased RFRP-3 fiber density and contacts on GnRH neurons. RFRP3 perikarya were also decreased in females exposed to 50 μg/kg BPA. Data suggest that BPA-induced premature puberty results from decreased inhibition of GnRH neurons.}, number={2}, journal={BIOLOGY OF REPRODUCTION}, author={Losa-Ward, Sandra M. and Todd, Karina L. and McCaffrey, Katherine A. and Tsutsui, Kazuyoshi and Patisaul, Heather B.}, year={2012}, month={Aug} }
 @article{patisaul_2012, title={Infertility in the Southern White Rhino: Is Diet the Source of the Problem?}, volume={153}, ISSN={["0013-7227"]}, DOI={10.1210/en.2012-1008}, abstractNote={As numerous species find themselves in peril due to human activity, the need to develop captive breeding strategies to save the most endangered among them has taken on an elevated sense of urgency. The Southern White Rhinoceros (Ceratotherium simum simum) has made a remarkable comeback in the wild but is still considered threatened due to habitat loss and poaching. Unfortunately, females born in captivity are subfertile, a phenomenon that is generating the risk of a significant population crash if the source of the problem cannot be identified. Numerous hypotheses including reproductive suppression by other females and continual close proximity to males have been purported and successively unsubstantiated. Could it come down to something as simple as diet? In this issue of Endocrinology, Tubbs et al. (26) provide evidence that it very well could. Their data suggest that the fertility of captive rhinos is being compromised, not by malnutrition but through endocrine disruption by phytoestrogens. 
 
Zoo animals receive zoo food. The goal of a zoo diet is to recapitulate the wild diet as closely as possible, but sometimes this is not economical or practical. Cheetahs, for example, are carnivores. In the wild they chase and capture prey to survive, and the biomechanical marvel, which is a body built for speeds achievable by no other land mammal, evinces the long history of evolutionary pressures constraining them to excel at this one pivotal task. They do not graze on the sea of grass that camouflages their whereabouts from the objects of their gustatory desires, nor could they perceive it as food, even when faced with starvation. Thus, it may seem odd that a zoo would elect to rear a captive population on soy-based cheetah chow, but from a fiscal and practical standpoint, it makes a certain amount of sense. Soy is a whole protein (meaning it contains all of the essential amino acids), making it a mainstay for most vegetarians. It is also lactose free, low in cholesterol, cheap, easy to obtain, and more acceptable to distribute to a hungry carnivore in front of a zoo full of visitors than, say, a baby gazelle. But cheetahs did not evolve to consume soy and the diversity of endocrine disrupting phytochemicals it contains. They become sick. In a case strikingly similar to that of the Southern White Rhinoceros, by the mid-1980s reproductive and liver disease threatened to derail the captive breeding program for the cheetah (1). The isoflavone phytoestrogens genistein and daidzein (Table 1) were to blame. 
 
 
 
Table 1. 
 
Structures and common sources of phytoestrogens found in pasture grasses and other legumes 
 
 
 
Could a similar situation be affecting an herbivore like the Southern White Rhinoceros, a species that evolved to graze? Phytoestrogens are nonsteroidal, estrogen-like compounds produced by plants, most notably the legumes (2), and play an important role in plant defense (3) including the recruitment of nitrogen fixing bacteria (4) and conferring resistance to fungi (5). Thus, plants produce them when under stress including disease, drought, and extreme temperatures. There are several classes of phytoestrogens (Table 1), all of which structurally resemble mammalian estrogens, and many are capable of binding and activating nuclear estrogen receptors (EsR1 and EsR2) (6). The most well-known class, the isoflavones, are most abundant in soybeans and soy-based foods, whereas the coumestans are prevalent in alfalfa, clover, and other pasture legumes such as the ones rhinos and other herbivores might graze on. It is the coumestans that appear to be contributing to the reproductive impairments reported in captive born Southern White Rhinoceros. 
 
Tubbs et al. (26) provide evidence that the Southern White Rhinoceros is more sensitive to estrogens and phytoestrogens than their cousin, the Great One-Horned Rhinoceros. EsR1 and EsR2 were cloned from both species and transfected into human embryonic kidney 293 cells to characterize and compare their binding properties. The findings emphasize how highly conserved estrogen receptor structure is across a diverse range of species, a feature that reflects the functional importance of these transcription factors. Although appreciable differences in binding affinity for endogenous estrogens or phytoestrogens were not found, receptor activation by coumestrol was significantly greater in the Southern White Rhinoceros than the Great One-Horned Rhinoceros. The authors surmise that this increased sensitivity may be contributing to the low fecundity in captive-born Southern White Rhinoceros females. Although more evidence is needed to affirm this conclusion, it is a reasonable presumption and not entirely remarkable because similar effects have been seen in other species including rodents (7), birds (8), cheetahs (1), and grazers like cattle and sheep (9–11). 
 
Research spanning 6 decades has shown that when consumed, phytoestrogens can have numerous deleterious effects on female reproduction including disruption of the ovulatory cycle and subfertility (7, 12–15). Menstrual cycle irregularities have also been reported in humans consuming a soy-rich diet (16). A growing body of work has revealed that phytoestrogens may interfere with the organizational role of endogenous estrogen in the developing neuroendocrine and reproductive system. Regardless of animal model used, manipulation of estrogen during specific critical windows of development throughout the perinatal period leads to a myriad of adverse health outcomes including malformations in the ovary, uterus, mammary gland and prostate, early puberty, reduced fertility, disrupted brain organization, and reproductive tract cancers (17–24). These effects are typically subtle but devastating, often not becoming apparent until reproductive maturity and are, for the most part, permanent. In contrast, when consumed in adulthood, the effects are largely reversible once intake is reduced but not always. 
 
Sheep raised on legume-rich pastures develop a suite of reproductive pathologies strikingly similar to those being observed in captive-born Southern White Rhinoceros, resulting in reduced conception rates and embryonic loss (9–11). Recognized since the 1940s, this syndrome is called clover disease and can be ameliorated by rearing the animals on cultivars of subterranean clover that contain fewer phytoestrogens. Prolonged exposure, however, can ultimately result in permanent infertility, even in adult ewes, because it induces the cervix to differentiate, making it more like the uterus and therefore unable to effectively store and transport spermatozoa (25). Other similar features between clover disease-stricken ewes and the subfertile Southern White Rhinoceros include estrous cycle irregularity, pyometra, endometrial hyperplasia, leiomyoma of the cervix and uterus, and cystic ovaries. In the Southern White Rhinoceros, it will be important to identify whether this syndrome results from embryonic exposure or chronic exposure across the life span. 
 
It will also be critical to pinpoint the dietary source of the problem. On average, captive Southern White Rhinoceros are fed a diet containing 58% mixed grasses, 24% commercial pellets (which likely contain soy), and 15% alfalfa. Estrogenic pasture plants include alfalfa, annual medics, soybeans, and several varieties of clover (subterranean, red, and white). Each contains a unique mixture of phytoestrogens. Alfalfa, for example, can produce high levels of coumestans, whereas subterranean clover can contain up to 5% dry weight isoflavones including genistein (9). Sensitivity to each class of phytoestrogen is species specific. For example, infertility in cattle has been associated with alfalfa but not subterranean clover, whereas sheep are sensitive to both. It remains to be determined to which pasture legume the Southern White Rhinoceros is most sensitive, but data from Tubbs et al. (26) suggest that it will be those that produce high levels of coumestrol, such as alfalfa. 
 
Phytoestrogens both expand our view of environmental substances with endocrine action and emphasize that the mammalian reproductive system has evolved the capacity to interact with them. For grazers, they may be an important signal of environmental quality because their prevalence increases when the plant is under stress. Thus, suppression of reproduction during such times may be adaptive for a species that lives in a marginal environment, like the Southern White Rhinoceros, but devastating if exposure is prolonged. Understanding these ecological relationships and recognizing the sources of endocrine disruptors in our environment are crucial to ensure the health and survival of imperiled species, such as the Southern White Rhinoceros.}, number={4}, journal={ENDOCRINOLOGY}, author={Patisaul, Heather B.}, year={2012}, month={Apr}, pages={1568–1571} }
 @article{patisaul_losa-ward_todd_mccaffrey_mickens_2012, title={Influence of ERβ selective agonism during the neonatal period on the sexual differentiation of the rat hypothalamic-pituitary-gonadal (HPG) axis}, volume={3}, ISSN={2042-6410}, url={http://dx.doi.org/10.1186/2042-6410-3-2}, DOI={10.1186/2042-6410-3-2}, abstractNote={It is well established that sexual differentiation of the rodent hypothalamic-pituitary-gonadal (HPG) axis is principally orchestrated by estrogen during the perinatal period. Here we sought to better characterize the mechanistic role the beta form of the estrogen receptor (ERβ) plays in this process. To achieve this, we exposed neonatal female rats to three doses (0.5, 1 and 2 mg/kg) of the ERβ selective agonist diarylpropionitrile (DPN) using estradiol benzoate (EB) as a positive control. Measures included day of vaginal opening, estrous cycle quality, GnRH and Fos co-localization following ovariectomy and hormone priming, circulating luteinizing hormone (LH) levels and quantification of hypothalamic kisspeptin immunoreactivity. A second set of females was then neonatally exposed to DPN, the ERα agonist propyl-pyrazole-triol (PPT), DPN+PPT, or EB to compare the impact of ERα and ERβ selective agonism on kisspeptin gene expression in pre- and post-pubescent females. All three DPN doses significantly advanced the day of vaginal opening and induced premature anestrus. GnRH and Fos co-labeling, a marker of GnRH activation, following ovariectomy and hormone priming was reduced by approximately half at all doses; the magnitude of which was not as large as with EB or what we have previously observed with the ERα agonist PPT. LH levels were also correspondingly lower, compared to control females. No impact of DPN was observed on the density of kisspeptin immunoreactive (-ir) fibers or cell bodies in the arcuate (ARC) nucleus, and kisspeptin-ir was only significantly reduced by the middle (1 mg/kg) DPN dose in the preoptic region. The second experiment revealed that EB, PPT and the combination of DPN+PPT significantly abrogated preoptic Kiss1 expression at both ages but ARC expression was only reduced by EB. Our results indicate that selective agonism of ERβ is not sufficient to completely achieve male-typical HPG organization observed with EB or an ERα agonist.}, number={1}, journal={Biology of Sex Differences}, publisher={Springer Nature}, author={Patisaul, Heather B and Losa-Ward, Sandra M and Todd, Karina L and McCaffrey, Katherine A and Mickens, Jillian A}, year={2012}, pages={2} }
 @article{jefferson_patisaul_williams_2012, title={Reproductive consequences of developmental phytoestrogen exposure}, volume={143}, ISSN={1470-1626 1741-7899}, url={http://dx.doi.org/10.1530/rep-11-0369}, DOI={10.1530/rep-11-0369}, abstractNote={Phytoestrogens, estrogenic compounds derived from plants, are ubiquitous in human and animal diets. These chemicals are generally much less potent than estradiol but act via similar mechanisms. The most common source of phytoestrogen exposure to humans is soybean-derived foods that are rich in the isoflavones genistein and daidzein. These isoflavones are also found at relatively high levels in soy-based infant formulas. Phytoestrogens have been promoted as healthy alternatives to synthetic estrogens and are found in many dietary supplements. The aim of this review is to examine the evidence that phytoestrogen exposure, particularly in the developmentally sensitive periods of life, has consequences for future reproductive health.}, number={3}, journal={REPRODUCTION}, publisher={Bioscientifica}, author={Jefferson, Wendy N and Patisaul, Heather B and Williams, Carmen J}, year={2012}, month={Mar}, pages={247–260} }
 @article{cao_patisaul_2012, title={Sex-specific expression of estrogen receptors α and β and Kiss1 in the postnatal rat amygdala}, volume={521}, ISSN={0021-9967}, url={http://dx.doi.org/10.1002/cne.23185}, DOI={10.1002/cne.23185}, abstractNote={AbstractThe rodent amygdaloid complex is composed of numerous subnuclei important for the sex‐specific regulation of sociosexual behavior. Although estrogen receptors (ERs) are critical for organizing functional and cytoarchitectural sex differences in these subnuclei, a detailed developmental profile of ER expression in the amygdaloid complex is not available. Moreover, the kisspeptin gene (Kiss1) was recently identified in the adult amygdala, but it remains unknown if it is expressed during development. To fill these data gaps, rat brains (5–7/group) were assessed on postnatal days (PNDs) 0, 2, 4, 7, and 19 for ER alpha (ERα; Esr1), beta (ERβ; Esr2), and Kiss1 expression using in situ hybridization. Expression was quantified in the posterodorsal portion of the medial amygdala posterodorsal (MePD), lateral (PLCo), and medial (PMCo) components of the posterior cortical nucleus, and the amygdalohippocampal area (AHi). ERα expression was high throughout the amygdala at birth, but sexually dimorphic only in the AHi. ERα expression in the MePD and the PLCo showed a U‐shaped expression pattern over time. In the PMCo, ERα expression decreased from PND 2 and remained low through PND 19. Sexually dimorphic expression of ERβ in the MePD was observed on PND 0, with higher levels in females, but reversed by PND 4 due to declining levels in females. No Kiss1 signal was observed in the postnatal amygdala, suggesting that expression arises after puberty. These data reveal that ER expression is region‐specific within the neonatal amygdala. These differences likely contribute to sex differences in sociosexual behavior across the lifespan. J. Comp. Neurol. 521:465–478, 2013. © 2012 Wiley Periodicals, Inc.}, number={2}, journal={Journal of Comparative Neurology}, publisher={Wiley}, author={Cao, Jinyan and Patisaul, Heather B.}, year={2012}, month={Dec}, pages={465–478} }
 @misc{frye_bo_calamandrei_calza_dessi-fulgheri_fernandez_fusani_kah_kajta_le page_et al._2012, title={Endocrine Disrupters: A Review of Some Sources, Effects, and Mechanisms of Actions on Behaviour and Neuroendocrine Systems}, volume={24}, ISSN={["1365-2826"]}, DOI={10.1111/j.1365-2826.2011.02229.x}, abstractNote={Some environmental contaminants interact with hormones and may exert adverse consequences as a result of their actions as endocrine disrupting chemicals (EDCs). Exposure in people is typically a result of contamination of the food chain, inhalation of contaminated house dust or occupational exposure. EDCs include pesticides and herbicides (such as dichlorodiphenyl trichloroethane or its metabolites), methoxychlor, biocides, heat stabilisers and chemical catalysts (such as tributyltin), plastic contaminants (e.g. bisphenol A), pharmaceuticals (i.e. diethylstilbestrol; 17α‐ethinylestradiol) or dietary components (such as phytoestrogens). The goal of this review is to address the sources, effects and actions of EDCs, with an emphasis on topics discussed at the International Congress on Steroids and the Nervous System. EDCs may alter reproductively‐relevant or nonreproductive, sexually‐dimorphic behaviours. In addition, EDCs may have significant effects on neurodevelopmental processes, influencing the morphology of sexually‐dimorphic cerebral circuits. Exposure to EDCs is more dangerous if it occurs during specific ‘critical periods’ of life, such as intrauterine, perinatal, juvenile or puberty periods, when organisms are more sensitive to hormonal disruption, compared to other periods. However, exposure to EDCs in adulthood can also alter physiology. Several EDCs are xenoestrogens, which can alter serum lipid concentrations or metabolism enzymes that are necessary for converting cholesterol to steroid hormones. This can ultimately alter the production of oestradiol and/or other steroids. Finally, many EDCs may have actions via (or independent of) classic actions at cognate steroid receptors. EDCs may have effects through numerous other substrates, such as the aryl hydrocarbon receptor, the peroxisome proliferator‐activated receptor and the retinoid X receptor, signal transduction pathways, calcium influx and/or neurotransmitter receptors. Thus, EDCs, from varied sources, may have organisational effects during development and/or activational effects in adulthood that influence sexually‐dimorphic, reproductively‐relevant processes or other functions, by mimicking, antagonising or altering steroidal actions.}, number={1}, journal={JOURNAL OF NEUROENDOCRINOLOGY}, author={Frye, C. A. and Bo, E. and Calamandrei, G. and Calza, L. and Dessi-Fulgheri, F. and Fernandez, M. and Fusani, L. and Kah, O. and Kajta, M. and Le Page, Y. and et al.}, year={2012}, month={Jan}, pages={144–159} }
 @article{cao_mickens_mccaffrey_leyrer_patisaul_2012, title={Neonatal Bisphenol A exposure alters sexually dimorphic gene expression in the postnatal rat hypothalamus}, volume={33}, ISSN={0161-813X}, url={http://dx.doi.org/10.1016/j.neuro.2011.11.002}, DOI={10.1016/j.neuro.2011.11.002}, abstractNote={Developmental exposure to Bisphenol A (BPA), a component of polycarbonate and epoxy resins, has been purported to adversely impact reproductive function in female rodents. Because neonatal life is a critical window for the sexual dimorphic organization of the hypothalamic–pituitary–gonadal (HPG) axis, interference with this process could underlie compromised adult reproductive physiology. The goal of the present study was to determine if neonatal BPA exposure interferes with sex specific gene expression of estrogen receptor alpha (ERα), ER beta (ERβ) and kisspeptin (Kiss1) in the anterior and mediobasal hypothalamus. Long Evans (LE) neonatal rats were exposed to vehicle, 10 μg estradiol benzoate (EB), 50 mg/kg BPA or 50 μg/kg BPA by subcutaneous injection daily from postnatal day 0 (PND 0) to PND 2. Gene expression was assessed by in situ hybridization on PNDs 4 and 10. Within the anterior hypothalamus ERα expression was augmented by BPA in PND 4 females, then fell to male-typical levels by PND 10. ERβ expression was not altered by BPA on PND 4, but significantly decreased or eliminated in both sexes by PND 10. Kiss1 expression was diminished by BPA in the anterior hypothalamus, especially in females. There were no significant impacts of BPA in the mediobasal hypothalamus. Collectively, BPA effects did not mirror those of EB. The results show that neonatal hypothalamic ER and Kiss1 expression is sensitive to BPA exposure. This disruption may alter sexually dimorphic hypothalamic organization and underlie adult reproductive deficiencies. Additionally, the discordant effects of EB and BPA indicate that BPA likely disrupts hypothalamic organization by a mechanism other than simply acting as an estrogen mimic.}, number={1}, journal={NeuroToxicology}, publisher={Elsevier BV}, author={Cao, Jinyan and Mickens, Jillian A. and McCaffrey, Katherine A. and Leyrer, Stephanie M. and Patisaul, Heather B.}, year={2012}, month={Jan}, pages={23–36} }
 @article{sullivan_hamilton_patisaul_2011, title={Neonatal agonism of ERβ impairs male reproductive behavior and attractiveness}, volume={60}, ISSN={0018-506X}, url={http://dx.doi.org/10.1016/j.yhbeh.2011.04.006}, DOI={10.1016/j.yhbeh.2011.04.006}, abstractNote={The organization of the developing male rodent brain is profoundly influenced by endogenous steroids, most notably estrogen. This process may be disrupted by estrogenic endocrine disrupting compounds (EDCs) resulting in altered sex behavior and the capacity to attract a mate in adulthood. To better understand the relative role each estrogen receptor (ER) subtype (ERα and ERβ) plays in mediating these effects, we exposed male Long Evans rats to estradiol benzoate (EB, 10 μg), vehicle, or agonists specific for ERβ (DPN, 1 mg/kg) or ERα (PPT, 1 mg/kg) daily for the first four days of life, and then assessed adult male reproductive behavior and attractiveness via a partner preference paradigm. DPN had a greater adverse impact than PPT on reproductive behavior, suggesting a functional role for ERβ in the organization of these male-specific behaviors. Therefore the impact of neonatal ERβ agonism was further investigated by repeating the experiment using vehicle, EB and additional DPN doses (0.5 mg/kg, 1 mg/kg, and 2 mg/kg bw). Exposure to DPN suppressed male reproductive behavior and attractiveness in a dose dependent manner. Finally, males were exposed to EB or an environmentally relevant dose of genistein (GEN, 10 mg/kg), a naturally occurring xenoestrogen, which has a higher relative binding affinity for ERβ than ERα. Sexual performance was impaired by GEN but not attractiveness. In addition to suppressing reproductive behavior and attractiveness, EB exposure significantly lowered the testis to body weight ratio, and circulating testosterone levels. DPN and GEN exposure only impaired behavior, suggesting that disrupted androgen secretion does not underlie the impairment.}, number={2}, journal={Hormones and Behavior}, publisher={Elsevier BV}, author={Sullivan, Alana W. and Hamilton, Peter and Patisaul, Heather B.}, year={2011}, month={Jul}, pages={185–194} }
 @article{novak_arnold_blazer_halden_klaper_kolpin_kriebel_love_martinovic-weigelt_patisaul_et al._2011, title={On the Need for a National (US) Research Program to Elucidate the Potential Risks to Human Health and the Environment Posed by Contaminants of Emerging Concern}, volume={45}, ISSN={["0013-936X"]}, DOI={10.1021/es200744f}, abstractNote={Department of Civil Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States Leetown Science Center, U.S. Geological Survey, Kearneysville, West Virginia 25430, United States School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85287, United States Great Lakes WATER Institute, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53204, United States Iowa Water Science Center, U.S. Geological Survey, Iowa City, Iowa 52244, United States Lowell Center for Sustainable Production, University of Massachusetts-Lowell, Lowell, Massachusetts 01854, United States Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States Department of Biology, University of St. Thomas, Saint Paul, Minnesota 55105, United States Department of Biology, North Carolina State University, Raleigh, North Carolina 27695, United States Department of Chemical and Environmental Engineering, University of Arizona, Tucson, Arizona 85721, United States Division of Biological Sciences, University of Missouri-Columbia, Columbia, Missouri 65211, United States Product Safety & Regulatory Affairs, Procter & Gamble, Cincinnati, Ohio 45201, United States Humphrey Institute of Public Affairs, University of Minnesota, Minneapolis, Minnesota 55455, United States}, number={9}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={Novak, P. J. and Arnold, W. A. and Blazer, V. S. and Halden, R. U. and Klaper, R. D. and Kolpin, D. W. and Kriebel, D. and Love, N. G. and Martinovic-Weigelt, D. and Patisaul, H. B. and et al.}, year={2011}, month={May}, pages={3829–3830} }
 @article{cao_patisaul_2011, title={Sexually dimorphic expression of hypothalamic estrogen receptors α and β and kiss1 in neonatal male and female rats}, volume={519}, ISSN={0021-9967}, url={http://dx.doi.org/10.1002/cne.22648}, DOI={10.1002/cne.22648}, abstractNote={AbstractRelease of gonadotropins in adult rodents is sex specific and dependent upon kisspeptin (Kiss1) neurons. This crucial pathway within the hypothalamic‐pituitary‐gonadal (HPG) axis is profoundly influenced by neonatal estrogens, which induce a male‐like phenotype. Classically, estrogen activity is mediated via the estrogen receptors α and β (ERα and ERβ), but the relative roles each plays in organizing the sex‐specific ontogeny of kisspeptin signaling pathways remain unresolved. Thus, the present study used in situ hybridization histochemistry (ISHH) to map the temporal and sexually dimorphic neonatal mRNA expression profiles of ERα, ERβ, and Kiss1 in the anterioventral periventricular nucleus (AVPV), medial preoptic area (MPOA), ventromedial nucleus (VMN), and arcuate nucleus (ARC), all regions critical for kisspeptin regulation of gonadotropin secretion. In general, females had higher levels of ERα, in all regions examined, a sex difference that persisted until postnatal day (PND) 19 except in the ARC. Males had significantly more ERβ expression in the AVPV at birth, but this sex difference was lost and then re‐emerged on PND 19, with females having more than males. VMN ERβ levels were higher in females until PND 19. Kiss1 was not detectable until PND 11 in the anterior hypothalamus, but expression levels were equivalent at birth in the ARC. By PND 2, ARC ERα and Kiss1 levels were abundant, sexually dimorphic (higher in females), and, respectively, showed a U‐ and a bell‐shaped pattern with age. Sex differences in ARC Kiss1 expression provide evidence that Kiss1 may play a role in the sexual dimorphic organization of the neonatal brain. These detailed profiles of neonatal Kiss1 and ERs mRNA levels will help elucidate the relative roles each plays in the sex‐specific, estrogen‐dependent organization of gonadotropin signaling pathways. J. Comp. Neurol. 519:2954–2977, 2011. © 2011 Wiley‐Liss, Inc.}, number={15}, journal={The Journal of Comparative Neurology}, publisher={Wiley}, author={Cao, Jinyan and Patisaul, Heather B.}, year={2011}, month={Aug}, pages={2954–2977} }
 @article{cao_patisaul_petersen_2011, title={Aryl hydrocarbon receptor activation in lactotropes and gonadotropes interferes with estradiol-dependent and -independent preprolactin, glycoprotein alpha and luteinizing hormone beta gene expression}, volume={333}, ISSN={["0303-7207"]}, DOI={10.1016/j.mce.2010.12.027}, abstractNote={Arylhydrocarbon receptor (Ahr) activation by 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD) interferes with female reproductive functions, but there is little information on the specific targets of TCDD in the hypothalamic–pituitary–gonadal (HPG) axis. In these studies, we found that TCDD upregulated known AhR target genes, cytochrome p450 1a1 (Cyp1a1), Cyp1a2 and Cyp1b1 in the rat pituitary gland. Moreover, 75% of pituitary lactotropes and 45% of gonadotropes contained Ahr mRNA, and most Ahr-containing cells were estrogen receptor 1 (Esr1)-positive. TCDD abrogated estradiol (E2)-induced prolactin (Prl) expression in vivo and in vitro; conversely, E2 blocked TCDD upregulation of luteinizing hormone beta (Lhb) and glycoprotein hormone alpha polypeptide (Cga) expression. TCDD had no effect on levels of Ahr mRNA, but upregulated Esr1 mRNA. E2 independently repressed Ahr and Esr1 expression and blocked TCDD upregulation of Esr1. Thus, complex interactions between Ahr and Esr alter Prl and luteinizing hormone (LH) synthesis by direct actions in lactotropes and gonadotropes. These findings provide important insights into how TCDD disrupts female reproductive functions.}, number={2}, journal={MOLECULAR AND CELLULAR ENDOCRINOLOGY}, author={Cao, Jinyan and Patisaul, Heather B. and Petersen, Sandra L.}, year={2011}, month={Feb}, pages={151–159} }
 @article{patisaul_2010, title={Assessing Risks from Bisphenol A Evaluating human health risks from endocrine disruptors' such as BPA is difficult, but animal studies suggest trouble is afoot}, volume={98}, ISSN={["1545-2786"]}, DOI={10.1511/2010.82.30}, number={1}, journal={AMERICAN SCIENTIST}, author={Patisaul, Heather}, year={2010}, pages={30–39} }
 @article{dickerson_cunningham_patisaul_woller_gore_2011, title={Endocrine Disruption of Brain Sexual Differentiation by Developmental PCB Exposure}, volume={152}, ISSN={["1945-7170"]}, DOI={10.1210/en.2010-1103}, abstractNote={AbstractIn mammals, sexual differentiation of the hypothalamus occurs during prenatal and early postnatal development due in large part to sex differences in hormones. These early organizational processes are critically important for the attainment and maintenance of adult reproductive functions. We tested the hypothesis that perinatal exposure to polychlorinated biphenyls (PCBs) that disrupt hormonal pathways would perturb reproductive maturation and the sexually dimorphic development of neuroendocrine systems in the preoptic area (POA). Pregnant Sprague-Dawley rats were injected on gestational d 16 and 18 with vehicle (dimethylsulfoxide), Aroclor 1221 (A1221, an estrogenic PCB mix), a reconstituted PCB mixture representing those highest in human body burden (PCBs 138, 153, 180), or estradiol benzoate, an estrogenic control. Male and female pups were monitored for somatic and reproductive development. In adulthood, some rats were perfused and used for immunohistochemistry of estrogen receptor α, kisspeptin, and coexpression of Fos in GnRH neurons. Other rats were used to obtain fresh-frozen POA dissections for use in a PCR-based 48-gene expression array. Pubertal onset was advanced and estrous cyclicity irregular in endocrine-disrupted females. Furthermore, sexual differentiation of female neuroendocrine systems was masculinized/defeminized. Specifically, in the adult female anteroventral periventricular nucleus, estrogen receptor α-cell numbers and kisspeptin fiber density were significantly decreased, as was GnRH-Fos coexpression. PCR analysis identified androgen receptor, IGF-I, N-methyl-d-aspartate receptor subunit NR2b, and TGFβ1 mRNAs as significantly down-regulated in endocrine-disrupted female POAs. These data suggest that developmental PCBs profoundly impair the sexual differentiation of the female hypothalamus.}, number={2}, journal={ENDOCRINOLOGY}, author={Dickerson, Sarah M. and Cunningham, Stephanie L. and Patisaul, Heather B. and Woller, Michael J. and Gore, Andrea C.}, year={2011}, month={Feb}, pages={581–594} }
 @article{losa_todd_sullivan_cao_mickens_patisaul_2011, title={Neonatal exposure to genistein adversely impacts the ontogeny of hypothalamic kisspeptin signaling pathways and ovarian development in the peripubertal female rat}, volume={31}, ISSN={["0890-6238"]}, DOI={10.1016/j.reprotox.2010.10.002}, abstractNote={Neonatal exposure to estrogenic endocrine disrupting compounds (EDCs) can advance pubertal onset and induce premature anestrous in female rats. It was recently discovered that hypothalamic kisspeptin (KISS) signaling pathways are sexually dimorphic and regulate both the timing of pubertal onset and estrous cyclicity. Thus we hypothesized that disrupted sex specific ontogeny of KISS signaling pathways might be a mechanism underlying these EDC effects. We first established the sex specific development of KISS gene expression, cell number and neural fiber density across peripuberty in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC), hypothesizing that the sexually dimorphic aspects of KISS signaling would be most vulnerable to EDCs. We next exposed female rats to the phytoestrogen genistein (GEN, 1 or 10 mg/kg bw), estradiol benzoate (EB, 10 μg), or vehicle from post natal day (P) 0–3 via subcutaneous (sc) injection. Animals were sacrificed on either P21, 24, 28, or 33 (n = 5–14 per group at each age). Vaginal opening was significantly advanced by EB and the higher dose of GEN compared to control animals and was accompanied by lower numbers of KISS immunoreactive fibers in the AVPV and ARC. Ovarian morphology was also assessed in all age groups for the presence of multiple oocyte follicles (MOFs). The number of MOFs decreased over time in each group, and none were observed in control animals by P24. MOFs were still present, however, in the EB and 10 mg/kg GEN groups beyond P24 indicating a disruption in the timing of ovarian development.}, number={3}, journal={REPRODUCTIVE TOXICOLOGY}, author={Losa, Sandra M. and Todd, Karina L. and Sullivan, Alana W. and Cao, Jinyan and Mickens, Jillian A. and Patisaul, Heather B.}, year={2011}, month={Apr}, pages={280–289} }
 @article{gore_patisaul_2010, title={Neuroendocrine disruption: Historical roots, current progress, questions for the future}, volume={31}, ISSN={["1095-6808"]}, DOI={10.1016/j.yfrne.2010.07.003}, abstractNote={In teleost fish, radial glial cells (RGCs) are progenitor cells for neurons and the major cell type synthesizing neuroestrogens. We hypothesized that chemical exposure impairs mitochondrial bioenergetics of RGCs, which then may lead to downstream consequences for neuroestrogen production. Here we provide proof of concept that mitochondria of RGCs can be perturbed by fungicides. We isolated RGCs from a mixed sex population of goldfish (Carassius auratus) and measured metabolic capacity of primary cells to a model mitotoxin fluazinam, a broad-spectrum fungicide that inhibits mitochondria electron transport chain (or ETC) Complex I. Using immunocytochemistry and real-time PCR, we demonstrate that the goldfish primary cell cultures are highly enriched for glia after multiple passages. Cytotoxicity assays revealed that glia treated with >25 μM fluazinam for 24 and 48-h showed reduced viability. As such, metabolic assays were conducted with non-cytotoxic concentrations (0.25–12.5 μM). Fluazinam did not affect oxygen consumption rates of RGCs at 24 h, but after 48 h, oligomycin induced ATP-linked respiration was decreased by both 6.25 and 12.5 μM fluazinam. Moreover, concentrations as low as 0.25 μM disrupted the mitochondrial membrane potential of RGCs, reflecting strong uncoupling effects of the fungicide on mitochondria. Here we provide proof of concept that mitochondrial bioenergetics of teleostean RGCs can be responsive to agrochemicals. Additional studies are required to address low-dose exposures in vivo and to determine if metabolic disruption impairs neuroendocrine functions of RGCs. We propose this mechanism constitutes a novel aspect of neuroendocrine disruption, significant because dysregulation of neuron–glia communication is expected to contribute to neuroendocrine disruption.}, number={4}, journal={FRONTIERS IN NEUROENDOCRINOLOGY}, author={Gore, Andrea C. and Patisaul, Heather B.}, year={2010}, month={Oct}, pages={395–399} }
 @article{adewale_todd_mickens_patisaul_2011, title={The impact of neonatal bisphenol-A exposure on sexually dimorphic hypothalamic nuclei in the female rat}, volume={32}, ISSN={["1872-9711"]}, DOI={10.1016/j.neuro.2010.07.008}, abstractNote={Now under intense scrutiny, due to its endocrine disrupting properties, the potential threat the plastics component bisphenol-A (BPA) poses to human health remains unclear. Found in a multitude of polycarbonate plastics, food and beverage containers, and medical equipment, BPA is thought to bind to estrogen receptors (ERs), thereby interfering with estrogen-dependent processes. Our lab has previously shown that exposure to BPA (50 mg/kg bw or 50 μg/kg bw) during the neonatal critical period is associated with advancement of puberty, early reproductive senescence and ovarian malformations in female Long Evans rats. Here, using neural tissue obtained from the same animals, we explored the impact of neonatal BPA exposure on the development of sexually dimorphic hypothalamic regions critical for female reproductive physiology and behavior. Endpoints included quantification of oxytocin-immunoreactive neurons (OT-ir) in the paraventricular nucleus (PVN), serotonin (5-HT-ir) fiber density in the ventrolateral subdivision of the ventromedial nucleus (VMNvl) as well as ERα-ir neuron number in the medial preoptic area (MPOA), the VMNvl, and the arcuate nucleus (ARC). Both doses of BPA increased the number of OT-ir neurons within the PVN, but no significant effects were seen on 5-HT-ir fiber density or ERα-ir neuron number in any of the areas analyzed. In addition to hypothalamic development, we also assessed female sex behavior and body weight. No effect of BPA on sexual receptivity or proceptive behavior in females was observed. Females treated with BPA, however, weighed significantly more than control females by postnatal day 99. This effect of BPA on weight is critical because alterations in metabolism, are frequently associated with reproductive dysfunction. Collectively, the results of this and our prior study indicate that the impact of neonatal BPA exposure within the female rat hypothalamus is region specific and support the hypothesis that developmental BPA exposure may adversely affect reproductive development in females.}, number={1}, journal={NEUROTOXICOLOGY}, author={Adewale, Heather B. and Todd, Karina L. and Mickens, Jillian A. and Patisaul, Heather B.}, year={2011}, month={Jan}, pages={38–49} }
 @misc{patisaul_jefferson_2010, title={The pros and cons of phytoestrogens}, volume={31}, ISSN={["1095-6808"]}, DOI={10.1016/j.yfrne.2010.03.003}, abstractNote={Phytoestrogens are plant derived compounds found in a wide variety of foods, most notably soy. A litany of health benefits including a lowered risk of osteoporosis, heart disease, breast cancer, and menopausal symptoms, are frequently attributed to phytoestrogens but many are also considered endocrine disruptors, indicating that they have the potential to cause adverse health effects as well. Consequently, the question of whether or not phytoestrogens are beneficial or harmful to human health remains unresolved. The answer is likely complex and may depend on age, health status, and even the presence or absence of specific gut microflora. Clarity on this issue is needed because global consumption is rapidly increasing. Phytoestrogens are present in numerous dietary supplements and widely marketed as a natural alternative to estrogen replacement therapy. Soy infant formula now constitutes up to a third of the US market, and soy protein is now added to many processed foods. As weak estrogen agonists/antagonists with molecular and cellular properties similar to synthetic endocrine disruptors such as Bisphenol A (BPA), the phytoestrogens provide a useful model to comprehensively investigate the biological impact of endocrine disruptors in general. This review weighs the evidence for and against the purported health benefits and adverse effects of phytoestrogens.}, number={4}, journal={FRONTIERS IN NEUROENDOCRINOLOGY}, author={Patisaul, Heather B. and Jefferson, Wendy}, year={2010}, month={Oct}, pages={400–419} }
 @article{patisaul_todd_mickens_adewale_2009, title={Impact of neonatal exposure to the ERα agonist PPT, bisphenol-A or phytoestrogens on hypothalamic kisspeptin fiber density in male and female rats}, volume={30}, ISSN={0161-813X}, url={http://dx.doi.org/10.1016/j.neuro.2009.02.010}, DOI={10.1016/j.neuro.2009.02.010}, abstractNote={Neonatal exposure to endocrine disrupting compounds (EDCs) can impair reproductive physiology, but the specific mechanisms by which this occurs remain largely unknown. Growing evidence suggests that kisspeptin (KISS) neurons play a significant role in the regulation of pubertal onset and ovulation, therefore disruption of KISS signaling could be a mechanism by which EDCs impair reproductive maturation and function. We have previously demonstrated that neonatal exposure to phytoestrogens decreases KISS fiber density in the anterior hypothalamus of female rats, an effect which was associated with early persistent estrus and the impaired activation gonadotropin releasing hormone (GnRH) neurons. The goals of the present study were to (1) determine if an ERα selective agonist (PPT) or bisphenol-A (BPA) could produce similar effects on hypothalamic KISS content in female rats and (2) to determine if male KISS fiber density was also vulnerable to disruption by EDCs. We first examined the effects of neonatal exposure to PPT, a low (50 μg/kg bw) BPA dose, and a high (50 mg/kg bw) BPA dose on KISS immunoreactivity (-ir) in the anterior ventral periventricular (AVPV) and arcuate (ARC) nuclei of adult female rats, using estradiol benzoate (EB) and a sesame oil vehicle as controls. AVPV KISS-ir, following ovariectomy (OVX) and hormone priming, was significantly lower in the EB and PPT groups but not the BPA groups. ARC KISS-ir levels were significantly diminished in the EB and high dose BPA groups, and there was a nonsignificant trend for lower KISS-ir in the PPT group. We next examined effects of neonatal exposure to a low (50 μg/kg bw) dose of BPA and the phytoestrogens genistein (GEN) and equol (EQ) on KISS-ir in the AVPV and ARC of adult male rats, using OVX females as an additional control group. None of the compounds affected KISS-ir in the male hypothalamus. Our results suggest that the organization of hypothalamic KISS fibers may be vulnerable to disruption by EDC exposure and that females might be more sensitive than males.}, number={3}, journal={NeuroToxicology}, publisher={Elsevier BV}, author={Patisaul, Heather B. and Todd, Karina L. and Mickens, Jillian A. and Adewale, Heather B.}, year={2009}, month={May}, pages={350–357} }
 @article{patisaul_adewale_2009, title={Long-term effects of environmental endocrine disruptors on reproductive physiology and behavior}, volume={3}, ISSN={1662-5153}, url={http://dx.doi.org/10.3389/neuro.08.010.2009}, DOI={10.3389/neuro.08.010.2009}, abstractNote={It is well established that, over the course of development, hormones shape the vertebrate brain such that sex specific physiology and behaviors emerge. Much of this occurs in discrete developmental windows that span gestation through the prenatal period, although it is now becoming clear that at least some of this process continues through puberty. Perturbation of this developmental progression can permanently alter the capacity for reproductive success. Wildlife studies have revealed that exposure to endocrine disrupting compounds (EDCs), either naturally occurring or man made, can profoundly alter reproductive physiology and ultimately impact entire populations. Laboratory studies in rodents and other species have elucidated some of the mechanisms by which this occurs and strongly indicate that humans are also vulnerable to disruption. Use of hormonally active compounds in human medicine has also unfortunately revealed that the developing fetus can be exposed to and affected by endocrine disruptors, and that it might take decades for adverse effects to manifest. Research within the field of environmental endocrine disruption has also contributed to the general understanding of how early life experiences can alter reproductive physiology and behavior through non-genomic, epigenetic mechanisms such as DNA methylation and histone acetylation. These types of effects have the potential to impact future generations if the germ line is affected. This review provides an overview of how exposure to EDCs, particularly those that interfere with estrogen action, impacts reproductive physiology and behaviors in vertebrates.}, journal={Frontiers in Behavioral Neuroscience}, publisher={Frontiers Media SA}, author={Patisaul, H.B. and Adewale, H.B.}, year={2009}, pages={10} }
 @article{adewale_jefferson_newbold_patisaul_2009, title={Neonatal Bisphenol-A Exposure Alters Rat Reproductive Development and Ovarian Morphology Without Impairing Activation of Gonadotropin-Releasing Hormone Neurons}, volume={81}, ISSN={["1529-7268"]}, DOI={10.1095/biolreprod.109.078261}, abstractNote={Developmental exposure to endocrine-disrupting compounds is hypothesized to adversely affect female reproductive physiology by interfering with the organization of the hypothalamic-pituitary-gonadal axis. Here, we compared the effects of neonatal exposure to two environmentally relevant doses of the plastics component bisphenol-A (BPA; 50 μg/kg and 50 mg/kg) with the ESR1 (formerly known as ERalpha)-selective agonist 4,4′,4″-(4-propyl-[1H]pyrazole-1,3,5-triyl)trisphenol (PPT; 1 mg/kg) on the development of the female rat hypothalamus and ovary. An oil vehicle and estradiol benzoate (EB; 25 μg) were used as negative and positive controls. Exposure to EB, PPT, or the low dose of BPA advanced pubertal onset. A total of 67% of females exposed to the high BPA dose were acyclic by 15 wk after vaginal opening compared with 14% of those exposed to the low BPA dose, all of the EB- and PPT-treated females, and none of the control animals. Ovaries from the EB-treated females were undersized and showed no evidence of folliculogenesis, whereas ovaries from the PPT-treated females were characterized by large antral-like follicles, which did not appear to support ovulation. Severity of deficits within the BPA-treated groups increased with dose and included large antral-like follicles and lower numbers of corpora lutea. Sexual receptivity, examined after ovariectomy and hormone replacement, was normal in all groups except those neonatally exposed to EB. FOS induction in hypothalamic gonadotropic (GnRH) neurons after hormone priming was impaired in the EB- and PPT-treated groups but neither of the BPA-treated groups. Our data suggest that BPA disrupts ovarian development but not the ability of GnRH neurons to respond to steroid-positive feedback.}, number={4}, journal={BIOLOGY OF REPRODUCTION}, author={Adewale, Heather B. and Jefferson, Wendy N. and Newbold, Retha R. and Patisaul, Heather B.}, year={2009}, month={Oct}, pages={690–699} }
 @article{pazol_northcutt_patisaul_wallen_wilson_2009, title={Progesterone and medroxyprogesterone acetate differentially regulate α4 subunit expression of GABAA receptors in the CA1 hippocampus of female rats}, volume={97}, ISSN={0031-9384}, url={http://dx.doi.org/10.1016/j.physbeh.2009.01.021}, DOI={10.1016/j.physbeh.2009.01.021}, abstractNote={The Women's Health Initiative trials - in which more extreme adverse outcomes were observed in the medroxyprogesterone acetate (MPA) + conjugated equine estrogen (CEE) arm, as compared to the CEE only arm - suggest that the addition of MPA to estrogen treatment has undesirable consequences. An important question raised by these results is whether the adverse outcomes observed in the progestin arm can be attributed to effects that are unique to MPA or are common to all progestins. In this study we explored the potential for MPA and progesterone (P4) to differentially impact neuroendocrine function by comparing their effects on mRNA expression for the alpha4 subunit of GABA(a) receptors in the CA1 hippocampus of female rats. Prior research has shown that P4, acting through its reduced metabolite allopregnanolone (AP), can mediate alpha4 subunit expression, thereby altering GABA(A) receptor gated currents. By contrast, MPA competitively inhibits the enzymes necessary for the synthesis of AP. In this study, ovariectomized females were primed with estradiol benzoate and then treated with P4, MPA, or vehicle. Subjects were sacrificed 12 h or 24 h later and in situ hybridization was used to measure alpha4 mRNA in the CA1 hippocampus. At 12 h but not 24 h, alpha4 mRNA was reduced in the P4 group as compared to the MPA group, and as compared to the vehicle group. These results suggest that MPA, while progestational in terms of its effects in the uterus, is not a simple substitute for P4 in other systems. The relative impact of these two progestins on neuroendocrine function must be carefully explored.}, number={1}, journal={Physiology & Behavior}, publisher={Elsevier BV}, author={Pazol, Karen and Northcutt, Katharine V. and Patisaul, Heather B. and Wallen, Kim and Wilson, Mark E.}, year={2009}, month={Apr}, pages={58–61} }
 @misc{bateman_patisaul_2008, title={Disrupted female reproductive physiology following neonatal exposure to phytoestrogens or estrogen specific ligands is associated with decreased GnRH activation and kisspeptin fiber density in the hypothalamus}, volume={29}, ISSN={["1872-9711"]}, DOI={10.1016/j.neuro.2008.06.008}, abstractNote={It is well established that estrogen administration during neonatal development can advance pubertal onset and prevent the maintenance of regular estrous cycles in female rats. This treatment paradigm also eliminates the preovulatory rise of gonadotropin releasing hormone (GnRH). It remains unclear, however, through which of the two primary forms of the estrogen receptor (ERα or ERβ) this effect is mediated. It is also unclear whether endocrine disrupting compounds (EDCs) can produce similar effects. Here we compared the effect of neonatal exposure to estradiol benzoate (EB), the ERα specific agonist 1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT), the ERβ specific agonist diarylpropionitrile (DPN) and the naturally occurring EDCs genistein (GEN) and equol (EQ) on pubertal onset, estrous cyclicity, GnRH activation, and kisspeptin content in the anteroventral periventricular (AVPV) and arcuate (ARC) nuclei. Vaginal opening was significantly advanced by EB and GEN. By 10 weeks post-puberty, irregular estrous cycles were observed in all groups except the control group. GnRH activation, as measured by the percentage of immunopositive GnRH neurons that were also immunopositive for Fos, was significantly lower in all treatment groups except the DPN group compared to the control group. GnRH activation was absent in the PPT group. These data suggest that neonatal exposure to EDCs can suppress GnRH activity in adulthood, and that ERα plays a pivotal role in this process. Kisspeptins (KISS) have recently been characterized to be potent stimulators of GnRH secretion. Therefore we quantified the density of KISS immunolabeled fibers in the AVPV and ARC. In the AVPV, KISS fiber density was significantly lower in the EB and GEN groups compared to the control group but only in the EB and PPT groups in the ARC. The data suggest that decreased stimulation of GnRH neurons by KISS could be a mechanism by which EDCs can impair female reproductive function.}, number={6}, journal={NEUROTOXICOLOGY}, author={Bateman, Heather L. and Patisaul, Heather B.}, year={2008}, month={Nov}, pages={988–997} }
 @article{patisaul_adewale_mickens_2009, title={Neonatal agonism of ERα masculinizes serotonergic (5-HT) projections to the female rat ventromedial nucleus of the hypothalamus (VMN) but does not impair lordosis}, volume={196}, ISSN={0166-4328}, url={http://dx.doi.org/10.1016/j.bbr.2008.09.026}, DOI={10.1016/j.bbr.2008.09.026}, abstractNote={Serotonin (5-HT) is known to play a role in the suppression of the lordosis response in males. We have previously shown that there is a sex difference in the density of 5-HT immunoreactive (5-HT-ir) fibers in the ventrolateral division of the adult ventromedial nucleus of the hypothalamus (VMNvl) and that neonatal administration of estradiol (E2) increases 5-HT-ir in the female VMNvl to male-typical levels. Here we demonstrate that postnatal administration of the ERα agonist 1,3,5-tris(4-Hydroxyphenyl)-4-propyl-1H-pyrazole (PPT), but not the ERβ agonist diarylpropionitrile (DPN), also masculinizes 5-HT-ir in the female VMNvl, suggesting a mechanistic role for ERα in this process. Sexual receptivity, as ascertained by the lordosis quotient, was unaffected by either PPT or DPN treatment but nearly abolished by estradiol benzoate (EB), a synthetic estrogen with high affinity for both ERα and ERβ. Collectively, these observations show that postnatal estrogens increase the density of 5-HT projections to the VMNvl via an ERα dependent mechanism, but that this increased inhibitory input is not sufficient to suppress the lordosis response.}, number={2}, journal={Behavioural Brain Research}, publisher={Elsevier BV}, author={Patisaul, Heather B. and Adewale, Heather B. and Mickens, Jillian A.}, year={2009}, month={Jan}, pages={317–322} }
 @article{patisaul_bateman_2008, title={Neonatal exposure to endocrine active compounds or an ERβ agonist increases adult anxiety and aggression in gonadally intact male rats}, volume={53}, ISSN={0018-506X}, url={http://dx.doi.org/10.1016/j.yhbeh.2008.01.008}, DOI={10.1016/j.yhbeh.2008.01.008}, abstractNote={Endocrine active compounds (EACs) have been shown to influence a number of reproductive endpoints but less is known about how they might affect other hormone dependent behaviors including anxiety and aggression. Recent evidence suggests that these effects may be mediated through the beta form of the estrogen receptor (ERbeta). Using male Long Evans rats, we sought to determine how neonatal exposure to EACs affects anxiety and aggression in adulthood. Anxiety was assessed using the elevated plus maze and aggression was assessed 8 weeks later using the resident intruder test. To gain insight into which ER subtype (ERalpha vs ERbeta) might be mediating these effects we used agonists specific for ERalpha (1,3,5-tris(4-Hydroxyphenyl)-4-propyl-1H-pyrazole (PPT)) or ERbeta (Diarylpropionitrile (DPN)) as additional treatment groups. For these experiments the synthetic EAC bisphenol-A (BPA) and the phytoestrogen metabolite equol (EQ) were used. Male neonates were injected with either 0.05 ml sesame oil (control), 50 microg estradiol benzoate (EB), 1 mg/kg DPN, 1 mg/kg PPT, 50 microg/kg BPA, or 10 mg/kg EQ daily for 4 days beginning on the day of birth (PND 0). Compared to the oil treated controls, significantly fewer open arm entries were made by the males neonatally treated with DPN, EQ, or BPA. The DPN and EQ treated males were also more aggressive compared to the controls. These findings suggest that neonatal exposure to EACs with agonistic activity on ERbeta may influence affective behavior in adulthood, including anxiety and aggression.}, number={4}, journal={Hormones and Behavior}, publisher={Elsevier BV}, author={Patisaul, Heather B. and Bateman, Heather L.}, year={2008}, month={Apr}, pages={580–588} }
 @article{patisaul_burke_hinkle_adewale_shea_2009, title={Systemic administration of diarylpropionitrile (DPN) or phytoestrogens does not affect anxiety-related behaviors in gonadally intact male rats}, volume={55}, ISSN={["1095-6867"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-58849100773&partnerID=MN8TOARS}, DOI={10.1016/j.yhbeh.2008.11.004}, abstractNote={The development of highly selective agonists for the two major subforms of the estrogen receptor (ERalpha and ERbeta) has produced new experimental methodologies for delineating the distinct functional role each plays in neurobehavioral biology. It has also been suggested that these compounds might have the potential to treat estrogen influenced behavioral disorders, such as anxiety and depression. Prior work has established that the ERbeta agonist, diarylpropionitrile (DPN) is anxiolytic in gonadectomized animals of both sexes, but whether or not this effect persists in gonadally intact individuals is unknown. Isoflavone phytoestrogens, also potent but less selective ERbeta agonists, have also been shown to influence anxiety in multiple species and are becoming more readily available to humans as health supplements. Here we determined the effects of 0.5, 1 or 2 mg/kg DPN, 1 mg/kg of the ERalpha agonist propyl-pyrazole-triol (PPT), 3 or 20 mg/kg of the isoflavone equol (EQ) and 3 or 20 mg/kg of the isoflavone polyphenol resveratrol (RES) on anxiety behavior in the gonadally intact male rat using the light/dark box and the elevated plus maze. We first determined that DPN can be successfully administered either orally or by subcutaneous injection, although plasma DPN levels are significantly lower if given orally. Once injected, plasma levels peak rapidly and then decline to baseline levels within 3 h of administration. For the behavioral studies, all compounds were injected and the animals were tested within 3 h of treatment. None of the compounds, at any of the doses, significantly altered anxiety-related behavior. Plasma testosterone levels were also not significantly altered suggesting that these compounds do not interfere with endogenous androgen levels. The results suggest that the efficacy of ERbeta agonists may depend on gonadal status. Therefore the therapeutic potential of ERbeta selective agonists to treat mood disorders may be limited.}, number={2}, journal={HORMONES AND BEHAVIOR}, author={Patisaul, Heather B. and Burke, Katherine T. and Hinkle, Ruth E. and Adewale, Heather B. and Shea, Damian}, year={2009}, month={Feb}, pages={319–328} }
 @article{patisaul_polston_2008, title={Influence of endocrine active compounds on the developing rodent brain}, volume={57}, ISSN={0165-0173}, url={http://dx.doi.org/10.1016/j.brainresrev.2007.06.008}, DOI={10.1016/j.brainresrev.2007.06.008}, abstractNote={Changes in the volumes of sexually dimorphic brain nuclei are often used as a biomarker for developmental disruption by endocrine-active compounds (EACs). However, these gross, morphological analyses do not reliably predict disruption of cell phenotype or neuronal function. Therefore, an experimental approach that simultaneously assesses anatomical, physiological and behavioral endpoints is required when developing risk assessment models for EAC exposure. Using this more comprehensive approach we have demonstrated that the disruption of nuclear volume does not necessarily coincide with disruption of cellular phenotype or neuroendocrine function in two sexually dimorphic brain nuclei: the anteroventral periventricular nucleus of the hypothalamus (AVPV) and the sexually dimorphic nucleus of the preoptic area (SDN). These results demonstrate that nuclear volume is likely not an appropriate biomarker for EAC exposure. We further demonstrated that neonatal exposure to the EACs genistein (GEN) and Bisphenol-A (BPA) can affect sexually dimorphic brain morphology and neuronal phenotypes in adulthood with regional and cellular specificity suggesting that effects observed in one brain region may not be predictive of effects within neighboring regions. Finally, developmental EAC exposure has been shown to affect a variety of sexually dimorphic behaviors including reproductive behavior. These effects are likely to have a broad impact as maladaptive behavior could translate to decreased fitness of entire populations. Collectively, these findings emphasize the need to employ a comprehensive approach that addresses anatomical, functional and behavioral endpoints when evaluating the potential effects of EAC exposure.}, number={2}, journal={Brain Research Reviews}, publisher={Elsevier BV}, author={Patisaul, Heather B. and Polston, Eva K.}, year={2008}, month={Mar}, pages={352–362} }
 @article{patisaul_fortino_polston_2008, title={Sex Differences in Serotonergic But Not γ-Aminobutyric Acidergic (GABA) Projections to the Rat Ventromedial Nucleus of the Hypothalamus}, volume={149}, ISSN={0013-7227 1945-7170}, url={http://dx.doi.org/10.1210/en.2007-0666}, DOI={10.1210/en.2007-0666}, abstractNote={Hormonal conditions that elicit lordosis in female rats are ineffective in males, suggesting that this behavior is actively suppressed in males. Previous studies theorize that serotonergic and γ-aminobutyric acidergic (GABA) inputs to the ventrolateral division of the ventromedial nucleus of the hypothalamus (VMNvl) may contribute to lordosis inhibition in males. Using triple-label immunofluorescent techniques, the present studies explored potential sex differences in the density of these projections within three hypothalamic sites: the VMNvl, the arcuate nucleus (ARC), and the dorsomedial nucleus of the hypothalamus. Antibodies directed against HuC/D, estrogen receptor (ER)-α and either serotonin (5-HT) or the γ-aminobutyric acid synthetic enzyme glutamic acid decarboxylase-65 were used to compare the densities of glutamic acid decarboxylase (GAD)-65- and 5-HT-containing fibers in each brain area, the percentage of VMNvl HuC/D immunoreactive (ir) neurons that contained ERα, and the percentage of HuC/D and ERα double-labeled cells receiving apparent contacts from 5-HT fibers between adult, gonadectomized male and female rats. The densities of VMNvl and ARC 5-HT immunolabeled fibers were significantly higher in the males, and the percentage of VMNvl HuC/D-ir neurons containing ERα was significantly higher in the females. The percentage of HuC/D-ir cells contacted by 5-HT fibers was significantly higher in the males, compared with the females, but there was no sex difference in the proportion of those cells receiving contacts that were ERα-ir. Neonatal administration of estradiol but not genistein masculinized 5-HT content in the adult female VMNvl, but the percentage of HuC/D-ir cells colabeled with ERα was not significantly affected by treatment. A similar, but not statistically significant, pattern was observed in the ARC. These findings suggest that the development of serotonergic inputs to the male VMNvl is orchestrated by neonatal estradiol exposure. The hormone-dependent organization of these 5-HT projection patterns may be an important developmental mechanism accounting for sex-specific behaviors in adulthood.}, number={1}, journal={Endocrinology}, publisher={The Endocrine Society}, author={Patisaul, Heather B. and Fortino, Anne E. and Polston, Eva K.}, year={2008}, month={Jan}, pages={397–408} }
 @article{patisaul_fortino_polston_2007, title={Differential disruption of nuclear volume and neuronal phenotype in the preoptic area by neonatal exposure to genistein and bisphenol-A}, volume={28}, ISSN={["1872-9711"]}, DOI={10.1016/j.neuro.2006.10.001}, abstractNote={Changes in the volumes of sexually dimorphic brain nuclei are often used as a biomarker for developmental disruption by endocrine-active compounds (EACs). However, these gross, morphological analyses do not reliably predict disruption of cell phenotype or neuronal function. In the present experiments, we used a more comprehensive approach to assess whether postnatal exposure to the EACs genistein (GEN) or bisphenol-A (BIS) affected the development of two sexually dimorphic brain regions in male rats: the anteroventral periventricular nucleus of the hypothalamus (AVPV) and the sexually dimorphic nucleus of the preoptic area (SDN). In addition to nuclear volumes, we also measured the number of immunopositive calbindin neurons in the SDN and the activational patterns of gonadotropin-releasing hormone (GnRH) neurons, a neuronal population that is functionally linked to the AVPV. In rats, exposure of the neonatal male brain to endogenous estrogen, aromatized from testicular testosterone, is essential for the proper sexual differentiation of these endpoints. Thus, we hypothesized that exposure to BIS and GEN during this critical period could disrupt brain sexual differentiation. Animals were given four subcutaneous injections of sesame oil (control), 250 μg GEN, or 250 μg BIS at 12 h intervals over postnatal days (PND) 1 and 2, gonadectomized on PND 85, and treated sequentially with estrogen and progesterone to stimulate Fos expression in GnRH neurons, a marker for their activation. A cohort of age-matched ovariectomized (OVX) females that were given the same hormone treatment in adulthood served as a positive control group. SDN volume was unchanged by treatment, but the number of calbindin neurons in the SDN was significantly increased by both BIS and GEN. GEN, but not BIS, demasculinized male AVPV volume, but patterns of GnRH neuronal activation were not affected by either compound. These results suggest that acute exposure to EACs during a critical developmental period can independently alter nuclear volumes of sexually dimorphic nuclei and their phenotypic profiles in a region specific manner.}, number={1}, journal={NEUROTOXICOLOGY}, author={Patisaul, Heather B. and Fortino, Anne E. and Polston, Eva K.}, year={2007}, month={Jan}, pages={1–12} }
 @article{patisaul_fortino_polston_2006, title={Neonatal genistein or bisphenol-A exposure alters sexual differentiation of the AVPV☆}, volume={28}, ISSN={0892-0362}, url={http://dx.doi.org/10.1016/j.ntt.2005.11.004}, DOI={10.1016/j.ntt.2005.11.004}, abstractNote={There is growing concern that naturally occurring and chemically manufactured endocrine-active compounds (EACs) may disrupt hormone-dependent events during central nervous system development. We examined whether postnatal exposure to the phytoestrogen genistein (GEN) or the plastics component bisphenol-A (BIS) affected sexual differentiation of the anteroventral periventricular nucleus of the hypothalamus (AVPV) in rats. The AVPV is sexually differentiated in rodents. The female AVPV is larger than the male AVPV and contains a higher number of cells expressing tyrosine hydroxylase (TH). Sexual differentiation of the AVPV results from exposure of the male nervous system to estrogen aromatized from testicular testosterone secreted in the first few days after birth. Thus, we hypothesized that exposure to EACs during this critical period could alter the sexually dimorphic expression of TH and the overall expression of estrogen receptor alpha (ERalpha) in the AVPV. Animals were given 4 subcutaneous injections of sesame oil (control), 50 microg 17beta-estradiol (E2), 250 microg GEN, or 250 microg BIS at 12-h intervals over postnatal days (PND) 1 and 2 and sacrificed on PND 19. E2 treatment masculinized TH immunoreactivity (TH-ir) in the female AVPV while exposure to GEN or BIS demasculinized TH-ir in the male AVPV. In addition, we identified a population of neurons co-expressing TH and ERalpha located primarily in the medial region of the AVPV. Normally, females have nearly three times as many double-labeled cells as males, but their numbers were defeminized by E2, GEN or BIS treatment. These results suggest that acute exposure to EACs during a critical developmental period alters AVPV development.}, number={1}, journal={Neurotoxicology and Teratology}, publisher={Elsevier BV}, author={Patisaul, H and Fortino, A and Polston, E}, year={2006}, month={Jan}, pages={111–118} }
 @article{patisaul_blum_luskin_wilson_2005, title={Dietary Soy Supplements Produce Opposite Effects on Anxiety in Intact Male and Female Rats in the Elevated Plus-Maze.}, volume={119}, ISSN={1939-0084 0735-7044}, url={http://dx.doi.org/10.1037/0735-7044.119.2.587}, DOI={10.1037/0735-7044.119.2.587}, abstractNote={The effects of 2 popular, commercially available soy phytoestrogen supplements on anxiety in male, diestrus female, and proestrus female rats were examined with an elevated plus-maze. Both of the soy supplements were anxiolytic in proestrus females but anxiogenic in males as determined by time spent in the open arms. No effect of diet was seen in the diestrus females. The observed changes in anxiety were not because of altered levels of gonadal hormones, as serum estrogen and progesterone levels were unaffected by diet in the females. The results suggest that the soy supplements have sex- and cycle-specific effects on anxiety.}, number={2}, journal={Behavioral Neuroscience}, publisher={American Psychological Association (APA)}, author={Patisaul, Heather B. and Blum, Adele and Luskin, Jordan R. and Wilson, Mark E.}, year={2005}, pages={587–594} }
 @article{patisaul_2005, title={Phytoestrogen Action in the Adult and Developing Brain}, volume={17}, ISSN={0953-8194 1365-2826}, url={http://dx.doi.org/10.1111/j.1365-2826.2005.01268.x}, DOI={10.1111/j.1365-2826.2005.01268.x}, abstractNote={AbstractSoy isoflavonoids are plant phytoestrogens available as dietary supplements and are increasingly advocated as a natural alternative to oestrogen replacement therapy. As weak oestrogen agonists/antagonists with a range of other enzymatic activities, the isoflavonoids provide a useful model to investigate the actions of endocrine disruptors. Here, the activational and organisational effects of these compounds on the brain are reviewed. In spite of their preferential affinity for oestrogen receptor (ER)βin vitro, isoflavonoids act in vivo through both ERα and ERβ. Their neurobehavioural actions are largely anti‐oestrogenic, either antagonising or producing an action in opposition to that of oestradiol. Small, physiologically relevant exposure levels can alter oestrogen‐dependent gene expression in the brain and affect complex behaviour in a wide range of species. The implications for these findings in humans, and particularly in infants, largely remain uninvestigated but are a subject of increasing public interest.}, number={1}, journal={Journal of Neuroendocrinology}, publisher={Wiley}, author={Patisaul, H. B.}, year={2005}, month={Jan}, pages={57–64} }
 @article{patisaul_luskin_wilson_2004, title={A soy supplement and tamoxifen inhibit sexual behavior in female rats}, volume={45}, ISSN={0018-506X}, url={http://dx.doi.org/10.1016/j.yhbeh.2003.12.006}, DOI={10.1016/j.yhbeh.2003.12.006}, abstractNote={In addition to displaying proceptive (hopping and darting) and receptive (lordosis) behaviors during a sexual encounter with a male, female rodents will regulate the timing of the encounter by engaging in a series of approaches and withdrawals from the male, a behavior termed paced mating behavior. Proceptive, receptive, and paced mating behaviors are all regulated by, and sensitive to, estrogen and progesterone, suggesting that compounds capable of disrupting these critical hormones may also perturb the display of female sexual behavior. The present experiments examined the impact of the selective estrogen receptor modulator (SERM) tamoxifen and a popular soy phytoestrogen dietary supplement on female sexual behavior in rats. Ovariectomized female rats were given either tamoxifen (TAMOX) by implant or the soy supplement through the diet then injected with estradiol benzoate (EB, 10 microg) or oil followed 48 h later with an injection of progesterone (P, 500 microg). Animals were then tested for sexual behavior 4 h after the P injection. Neither compound had any effect on sexual behavior when administered in conjunction with P alone; however, both significantly diminished receptive behavior, as measured by the lordosis quotient (LQ), in animals primed with both EB and P. Similarly, the hopping and darting rate was also significantly depressed in both the soy- and TAMOX-treated animals, compared to the EB- and P-treated controls, with the soy-treated animals showing significantly less proceptive behavior than the TAMOX-treated animals. Finally, soy but not TAMOX significantly attenuated paced mating behavior in animals compared to the EB- and P-treated controls. These results demonstrate that both the soy supplement and TAMOX act as estrogen antagonists on both proceptive and receptive behavior in female rats.}, number={4}, journal={Hormones and Behavior}, publisher={Elsevier BV}, author={Patisaul, Heather B and Luskin, Jordan R and Wilson, Mark E}, year={2004}, month={Apr}, pages={270–277} }
 @inbook{patisaul_whitten_2004, title={Dietary Phytoestrogens}, ISBN={9780429126659}, url={http://dx.doi.org/10.1201/9781420038866-5}, DOI={10.1201/9781420038866-5}, abstractNote={In general, compounds classified as "endocrine disruptors" are regarded as adverse substances and presumed to have deleterious effects on mammalian systems. Human exposure to these compounds is thus recommended to be as limited as possible and great effort is being undertaken to reduce or eliminate these compounds in the environment. Phytoestrogens occur at high levels in variety of foods, particularly those that are soy-based, such as soy infant formula, tofu, and soy flour. Numerous dietary supplements are also available that contain a wide range of phytoestrogens, particularly the isoflavones. Lignans are a minor component of plant cell walls. The plant lignans matairesinol and secoisolariciresinol are converted to the mammalian lignans enterlactone and enterodiol, respectively, by the resident bacterial flora of the gut. The isoflavonoids are divided into three major classes: isoflavones, isoflavans, and coumestans, of which the isoflavones are the most widely studied group. Phytoestrogenic isoflavonoids are less prevalent than lignans.}, booktitle={Endocrine Disruptors}, publisher={CRC Press}, author={Patisaul, Heather B. and Whitten, Patricia L.}, year={2004}, month={Nov}, pages={135–173} }
 @article{patisaul_aultman_bielsky_young_wilson_2003, title={Immediate and residual effects of tamoxifen and ethynylestradiol in the female rat hypothalamus}, volume={978}, ISSN={0006-8993}, url={http://dx.doi.org/10.1016/s0006-8993(03)02807-5}, DOI={10.1016/s0006-8993(03)02807-5}, abstractNote={Very little is known about the impact of selective estrogen receptor modulators (SERMs) on the brain. We examined the effects of tamoxifen (TAMOX) and the synthetic estrogen 17alpha-ethynylestradiol (EE) on estrogen-dependent gene expression and receptor binding in the female rat brain. Both immediate and residual effects were examined in both the presence and absence of 17beta-estradiol. Two groups of adult, ovariectomized, female rats (n=30 per group) were injected with TAMOX (5 mg/kg), EE (0.1 mg/kg), or sesame oil daily for 14 days. Animals from the first group were implanted with blank or 17beta-estradiol Silastic capsules concurrently with the last three SERM injections (immediate, group 1). Animals from the second group received either blank or 17beta-estradiol implants 2 weeks after the last injection (residual, group 2). All animals were sacrificed 72 h after implantation. TAMOX increased uterine weight in the absence of estrogen, but inhibited uterine weight gain in the presence of estrogen in both groups 1 and 2. TAMOX and EE increased oxytocin receptor binding in the ventromedial nucleus of the hypothalamus (VMN) in the absence of estrogen in both groups 1 and 2. The estrogen-dependent induction of PR mRNA expression in the VMN was significantly attenuated by TAMOX in group 1. Finally, TAMOX and EE had opposite effects on ERbeta mRNA expression in the paraventricular nucleus in the absence of 17beta-estradiol in group 1. Neither had any effect in group 2 when 17beta-estradiol was present. These results suggest that TAMOX has mixed agonist/antagonist effects in the female rat brain, many of which persist at least 2 weeks after the administration ceases.}, number={1-2}, journal={Brain Research}, publisher={Elsevier BV}, author={Patisaul, Heather B. and Aultman, Eleni A. and Bielsky, Isadora F. and Young, Larry J. and Wilson, Mark E.}, year={2003}, month={Jul}, pages={185–193} }
 @article{patisaul_scordalakes_young_rissman_2003, title={Oxytocin, But Not Oxytocin Receptor, is Regulated by Oestrogen Receptor β in the Female Mouse Hypothalamus}, volume={15}, ISSN={0953-8194 1365-2826}, url={http://dx.doi.org/10.1046/j.1365-2826.2003.01061.x}, DOI={10.1046/j.1365-2826.2003.01061.x}, abstractNote={AbstractIn the female rat, oestrogen receptor (ER) β is colocalized with both oxytocin‐ and vasopressin‐producing neurones in the paraventricular nucleus of the hypothalamus (PVN). In this study, we demonstrate that the same pattern of colocalization between ERβ and oxytocin exists in the female mouse. Because this nucleus contains only a negligible quantity of ERα, it is likely that the oestrogen‐dependent regulation of oxytocin and vasopressin synthesis in the PVN is mediated by ERβ. Thus, we compared the effect of ovarian hormones on oxytocin and vasopressin mRNA expression in the PVN of wild‐type (WT) and ERβ knockout (βERKO) mice. We also compared the effects of ovarian hormones on oxytocin receptor (OTR) expression in the medial amygdala (MeA) and ventromedial nucleus of the hypothalamus (VMN) in female WT and βERKO mice. Ovariectomized mice underwent long‐term treatment with oestradiol or oil. Progesterone was given concurrently on the final 7 days of treatment, and all mice were killed 48 h after the final progesterone injection. In the PVN, hormone treatment increased oxytocin mRNA expression in WT but not βERKO females. These results suggest that ERβ is necessary for the regulation of the expression of oxytocin in the PVN. Hormone treatment had no effect on vasopressin mRNA expression in the PVN, but significantly increased OTR binding in both the VMN and the MeA in both genotypes. Collectively, our data show region and peptide specific regulation by ERα and ERβ in the mouse hypothalamus.}, number={8}, journal={Journal of Neuroendocrinology}, publisher={Wiley}, author={Patisaul, H. B. and Scordalakes, E. M. and Young, L. J. and Rissman, E. F.}, year={2003}, month={Jul}, pages={787–793} }
 @article{patisaul_melby_whitten_young_2002, title={Genistein Affects ERβ- But Not ERα-Dependent Gene Expression in the Hypothalamus}, volume={143}, ISSN={0013-7227 1945-7170}, url={http://dx.doi.org/10.1210/endo.143.6.8843}, DOI={10.1210/endo.143.6.8843}, abstractNote={Isoflavone phytoestrogens are growing increasingly popular because of their reported cardiovascular and anticarcinogenic properties, but the effects of these compounds in the brain are largely unknown. In a previous study, we found that an isoflavone supplement, containing a mixture of soy phytoestrogens, inhibited estrogen-dependent female sexual behavior and was antiestrogenic for both ERα- and ERβ-dependent gene expression in the hypothalamus. Here we examined the impact of the soy isoflavone genistein, a major component of the supplement, on estrogen-dependent female sexual behavior and ERα- and ERβ-dependent gene expression in the rat brain. Genistein, at a dietary concentration of 100 or 500 ppm had no effect on lordosis behavior in rats. However, at 500 ppm genistein had differential activity through ERα and ERβ in the hypothalamus. Genistein had no effect, in either the presence or absence of 17β-E2, on oxytocin receptor density in the ventromedial nucleus of the hypothalamus, an estrogen-dependen...}, number={6}, journal={Endocrinology}, publisher={The Endocrine Society}, author={Patisaul, Heather B. and Melby, Melissa and Whitten, Patricia L. and Young, Larry J.}, year={2002}, month={Jun}, pages={2189–2197} }
 @article{whitten_patisaul_young_2002, title={Neurobehavioral actions of coumestrol and related isoflavonoids in rodents}, volume={24}, ISSN={0892-0362}, url={http://dx.doi.org/10.1016/s0892-0362(01)00192-1}, DOI={10.1016/s0892-0362(01)00192-1}, abstractNote={Isoflavonoids are plant estrogens that are increasingly advocated as a natural alternative to estrogen replacement therapy (ERT) and are available as dietary supplements. As weak estrogen agonists/antagonists with a range of other enzymatic activities, the isoflavonoids provide a useful model for the actions of endocrine disruptors. This paper reviews the responses of rodents to diets containing coumestrol or an isoflavone supplement in comparison to animals fed the phytoestrogen-free AIN76A diet. Neural mechanisms were investigated by examining isoflavonoid effects on ERα-dependent (regulation of oxytocin receptor [OTR] binding in the ventromedial nucleus of the hypothalamus [VMN]) and ERβ-dependent (regulation of ERβ mRNA in the paraventricular nucleus [PVN]) endpoints. Activational as well as organizational effects on sexual behavior and gonadotropin secretion were observed for coumestrol. Treatment of rat dams with a 100-ppm coumestrol diet from birth to postnatal day (PND) 21 induced premature anovulation in female offspring, and treatment from birth to PND 10 suppressed sexual behavior in male offspring. One-week treatment of ovariectomized (OVX) female rats with the same coumestrol diet increased ERβ mRNA expression in the PVN, an effect opposite to that of estradiol. Ten days of treatment with a 200-ppm coumestrol diet increased LH secretion in OVX wild-type mice, an effect opposite to the normal negative feedback effects of estradiol. No effects were observed in ERα knockout (ERαKO)-OVX females, indicating that coumestrol's action on LH was mediated through ERα. Similar activational effects were observed for the isoflavone diet. The lordotic response to estrogen was significantly reduced by 2 days of treatment of OVX adult females with an isoflavone diet providing 13 ppm genistein and 33 ppm daidzein. One week of treatment with the same isoflavone diet produced an effect opposite to that of estradiol in the PVN, increasing ERβ mRNA expression above control levels. These investigations show that, in spite of their preferential affinity for ERβ, isoflavonoids act through both ERα and ERβ. Moreover, their neurobehavioral actions were antiestrogenic, either antagonizing or producing an action in opposition to that of estradiol. This work demonstrates that even small, physiologically relevant exposure levels can alter estrogen-dependent gene expression in the brain and complex behavior.}, number={1}, journal={Neurotoxicology and Teratology}, publisher={Elsevier BV}, author={Whitten, Patricia L and Patisaul, Heather B and Young, Larry J}, year={2002}, month={Jan}, pages={47–54} }
 @article{jacob_temple_patisaul_young_rissman_2001, title={Coumestrol Antagonizes Neuroendocrine Actions of Estrogen via the Estrogen Receptor α}, volume={226}, ISSN={1535-3702 1535-3699}, url={http://dx.doi.org/10.1177/153537020122600406}, DOI={10.1177/153537020122600406}, abstractNote={ The phytoestrogen coumestrol has estrogenic actions on peripheral reproductive tissues. Yet in the brain this compound has both estrogenic and anti-estrogenic effects. We used estrogen receptor α knockout mice (ERαKO) to determine whether coumestrol has estrogenic actions in mice and also if these effects are mediated by the classic ERα. Female wild-type (WT) and ERαKO mice were ovariectomized and treated with estradiol (E2), dietary coumestrol, both, or neither compound. Ten days later the animals were sacrificed, blood was collected, and brain tissues were perfused. Fixed brains were sectioned and immunocytochemistry was employed to quantify progesterone receptors (PR) in the medial preoptic (POA) and ventromedial nucleus of the hypothalamus (VMN). Plasma was assayed for luteinizing hormone (LH). Estrogen treatment induced PR immunoreactivity in both regions in brains of WT females. In ERαKO mice, lower levels of PR were induced. The stimulatory effects of E2 on PR were attenuated in the POA by cotreatment with coumestrol, and the same trend was noted in the VMN. WT ovariectomized females treated with E2 had low levels of LH, while LH was high in untreated females and even higher in ovariectomized females treated with coumestrol. ERαKO females in all treatment groups had high levels of LH. Taken together, the results show that coumestrol has anti-estrogenic actions in the brain and pituitary and that ERα mediates these effects. }, number={4}, journal={Experimental Biology and Medicine}, publisher={SAGE Publications}, author={Jacob, Dena A. and Temple, Jennifer L. and Patisaul, Heather B. and Young, Larry J. and Rissman, Emilie F.}, year={2001}, month={Apr}, pages={301–306} }
 @article{whitten_patisaul_2001, title={Cross-species and interassay comparisons of phytoestrogen action.}, volume={109}, ISSN={0091-6765 1552-9924}, url={http://dx.doi.org/10.1289/ehp.01109s15}, DOI={10.1289/ehp.01109s15}, abstractNote={This paper compiles animal and human data on the biologic effects and exposure levels of phytoestrogens in order to identify areas of research in which direct species comparisons can be made. In vitro and in vivo assays of phytoestrogen action and potency are reviewed and compared to actions, dose-response relationships, and estimates of exposure in human subjects. Binding studies show that the isoflavonoid phytoestrogens are high-affinity ligands for estrogen receptors (ERs), especially ER beta, but have lower potency in whole-cell assays, perhaps because of interactions with binding proteins. Many other enzymatic actions require concentrations higher than those normally seen in plasma. In vivo data show that phytoestrogens have a wide range of biologic effects at doses and plasma concentrations seen with normal human diets. Significant in vivoresponses have been observed in animal and human tests for bone, breast, ovary, pituitary, vasculature, prostate, and serum lipids. The doses reported to be biologically active in humans (0.4--10 mg/kg body weight/day) are lower than the doses generally reported to be active in rodents (10--100 mg/kg body weight/day), although some studies have reported rodent responses at lower doses. However, available estimates of bioavailability and peak plasma levels in rodents and humans are more similar. Steroidogenesis and the hypothalamic-pituitary-gonadal axis appear to be important loci of phytoestrogen actions, but these inferences must be tentative because good dose-response data are not available for many end points. The similarity of reported proliferative and antiproliferative doses illustrates the need for fuller examination of dose-response relationships and multiple end points in assessing phytoestrogen actions.}, number={suppl 1}, journal={Environmental Health Perspectives}, publisher={Environmental Health Perspectives}, author={Whitten, P L and Patisaul, H B}, year={2001}, month={Mar}, pages={5–20} }
 @article{patisaul_dindo_whitten_young_2001, title={Soy Isoflavone Supplements Antagonize Reproductive Behavior and Estrogen Receptor α- and β-Dependent Gene Expression in the Brain*}, volume={142}, ISSN={0013-7227 1945-7170}, url={http://dx.doi.org/10.1210/endo.142.7.8241}, DOI={10.1210/endo.142.7.8241}, abstractNote={Epidemiological evidence suggests that isoflavone phytoestrogens may reduce the risk of cancer, osteoporosis, and heart disease, effects at least partially mediated by estrogen receptors alpha and beta (ERalpha and ERbeta). Because isoflavone dietary supplements are becoming increasingly popular and are frequently advertised as natural alternatives to estrogen replacement therapy, we have examined the effects of one of these supplements on estrogen-dependent behavior and ERalpha- and ERbeta-dependent gene expression in the brain. In the adult female rat brain, 17beta-estradiol treatment decreased ERbeta messenger RNA signal in the paraventricular nucleus by 41%, but supplement treatment resulted in a 27% increase. The regulation of ERbeta in the paraventricular nucleus is probably via an ERbeta-dependent mechanism. Similarly, in the ventromedial nucleus of the hypothalamus, supplement treatment diminished the estrogen-dependent up-regulation of oxytocin receptor by 10.5%. The regulation of oxytocin receptor expression in the ventromedial nucleus of the hypothalamus is via an ERalpha-dependent mechanism. Supplement treatment also resulted in a significant decrease in receptive behavior in estrogen- and progesterone-primed females. The observed disruption of sexual receptivity by the isoflavone supplement is probably due to antiestrogenic effects observed in the brain. These results suggest that isoflavone phytoestrogens are antiestrogenic on both ERalpha- and ERbeta-dependent gene expression in the brain and estrogen-dependent behavior.}, number={7}, journal={Endocrinology}, publisher={The Endocrine Society}, author={Patisaul, Heather B. and Dindo, Marietta and Whitten, Patricia L. and Young, Larry J.}, year={2001}, month={Jul}, pages={2946–2952} }
 @article{patisaul_whitten_young_1999, title={Regulation of estrogen receptor beta mRNA in the brain: opposite effects of 17β-estradiol and the phytoestrogen, coumestrol}, volume={67}, ISSN={0169-328X}, url={http://dx.doi.org/10.1016/s0169-328x(99)00058-3}, DOI={10.1016/s0169-328x(99)00058-3}, abstractNote={Estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta) are differentially distributed in the brain and likely mediate different estrogen-dependent processes. ERbeta is abundant in the bed nucleus of the stria terminalis, medial preoptic nucleus, paraventricular nucleus of the hypothalamus and the amygdala of the rat. In the paraventricular nucleus, which is devoid of ERalpha, ERbeta is colocalized with the neuropeptides, oxytocin and vasopressin, suggesting a potential functional role for ERbeta in the regulation of these peptides. We examined the regulation of ERbeta mRNA expression in the rat brain by 17beta-estradiol and the phytoestrogen, coumestrol. 17beta-Estradiol treatment decreased ERbeta mRNA in situ hybridization signal by 44.5% in the paraventricular nucleus of the hypothalamus (PVN), but had no effect in the bed nucleus of the stria terminalis (BnST) or the medial preoptic nucleus (MPA). In contrast, dietary exposure to coumestrol increased ERbeta mRNA signal by 47.5% in the PVN but had no effect in the BnST or the MPA. These data demonstrate that like ERalpha, ERbeta is down regulated by estrogen in a region specific manner in the rat brain. Furthermore, exposure to coumestrol may modulate ERbeta-dependent processes by acting as an anti-estrogen at ERbeta. This data contradicts results from cell transfection assays which suggest an estrogenic activity of coumestrol on ERbeta, indicating that the mode of action may be tissue specific, or that metabolism of dietary coumestrol may alter its effects. Because the highest concentrations of phytoestrogens are found in legumes, vegetables and grains, they are most prevalent in vegetarian and traditional Asian diets. Understanding the neuroendocrine effects of phytoestrogens is particularly important now that they are being marketed as a natural alternative to estrogen replacement therapy and sold in highly concentrated pills and powders.}, number={1}, journal={Molecular Brain Research}, publisher={Elsevier BV}, author={Patisaul, Heather B. and Whitten, Patricia L. and Young, Larry J.}, year={1999}, month={Apr}, pages={165–171} }