@article{chu_chan_ng_brown_siu_beale_gilger_wong_2008, title={Porcine global flash multifocal electroretinogram: Possible mechanisms for the glaucomatous changes in contrast response function}, volume={48}, ISSN={0042-6989}, url={http://dx.doi.org/10.1016/j.visres.2008.05.006}, DOI={10.1016/j.visres.2008.05.006}, abstractNote={The aim of this study was to obtain a better understanding of the cellular contributions to the porcine global flash mfERG by using a pharmacologic dissection method, together with the method using variation of stimulus contrast which has been used to demonstrate mfERG changes in human glaucoma.Global flash mfERGs with different stimulus-contrast settings (99%, 65%, 49% or 29%) were recorded from 14 eyes of ten 6-week-old Yorkshire pigs in control conditions and after suppression of inner retinal responses with inhalation of isoflurance (ISO), and injections of tetrodotoxin (TTX) and N-methyl-d-aspartic acid (NMDA). ON- and OFF-pathway responses were isolated by injection of 2-amino-4-phosphonobutyric acid (APB) and cis-2,3-piperidinedicarboylic acid (PDA).The porcine global flash mfERG consisted of an early direct component (DC) and a late induced component (IC). ISO and TTX removed inner retinal contributions to the IC; NMDA application further abolished the oscillatory wavelets in the DC and removed the residual IC waveform. The inner retina contributed regular oscillation-like wavelets (W1, W2 and W3) to the DC and shaped the IC. After removing the inner retinal contributions, the porcine global flash mfERG waveform becomes comparable to that obtained with conventional mfERG stimulation. The remaining waveform (smoothed DC) was mainly contributed by the ON- and OFF-bipolar cells as revealed after APB or PDA injection. Photoreceptors contributed a small signal to the leading edge of N1. The characteristic of contrast response function of DC was demonstrated to be contributed by the inner retinal oscillation-like wavelets.We believe that the DC of the porcine global flash mfERG is mainly composed of contributions from photoreceptors, and ON- and OFF-bipolar cells, where inner retinal activity partially shaped the DC with superimposed regular wavelets. However, the IC is dominated by inner retinal activity. The contrast response functions of DC consisted of both outer retinal response and oscillation-like wavelets of the inner retinal response. Both contain different characteristics during contrast modulation of the stimulus, where the changes of W2 of the inner retinal response seem independent of contrast modulation. The DC contrast response feature depends mainly on the relative contribution of inner retinal activities; the loss of inner retinal cells may alter the DC contrast response function, making it tend toward linearity.}, number={16}, journal={Vision Research}, publisher={Elsevier BV}, author={Chu, Patrick H.W. and Chan, Henry H.L. and Ng, Yiu-fai and Brown, Brian and Siu, Andrew W. and Beale, Brady A. and Gilger, Brian C. and Wong, Fulton}, year={2008}, month={Jul}, pages={1726–1734} }
 @article{ng_chan_chu_siu_to_beale_gilger_wong_2007, title={Pharmacologically defined components of the normal porcine multifocal ERG}, volume={116}, ISSN={0012-4486 1573-2622}, url={http://dx.doi.org/10.1007/s10633-007-9076-7}, DOI={10.1007/s10633-007-9076-7}, abstractNote={Multifocal electroretinograms (mfERG) from isoflurane anesthetized pigs were recorded and sequential application of TTX, NMDA, APB and PDA were used to identify contributions to the mfERG from inner retinal neurons, ON-pathway, OFF-pathway and photoreceptors. The cellular origins of the first-order kernel (K1) and the first slice of the second-order kernel (K2.1) porcine mfERG are contributed from both inner and outer retina. For the K1 waveform, the n1 involved responses of cone photoreceptors and OFF-bipolar cells. The leading edge of p1 is dominated by ON-bipolar cell depolarization. The rear edge of p1, n2 and p2 are dominated by ON-bipolar activities and shaped by the activities of OFF-bipolar cells and retinal cells with NMDAr and voltage-gated sodium channels other than ganglion cells. The p3 is mainly inner retinal activities. For the K2.1 waveform, the p1 and n1 are the summation of activities of ON-, OFF-bipolar cells and retinal cells rich in NMDAr and voltage-gated sodium channels other than ganglion cells. The p2 seems to be related to the ganglion cells. Better understanding of the cellular origins of the normal porcine mfERG will be useful for comparing and defining the functional changes that may occur in diseased retinas.}, number={3}, journal={Documenta Ophthalmologica}, publisher={Springer Science and Business Media LLC}, author={Ng, Yiu-fai and Chan, Henry H. L. and Chu, Patrick H. W. and Siu, Andrew W. and To, Chi-ho and Beale, Brady A. and Gilger, Brian C. and Wong, Fulton}, year={2007}, month={Aug}, pages={165–176} }
 @article{acton_beale_gilger_stoskopf_2006, title={Sustained Release Cyclosporine Therapy for Bilateral Keratoconjunctivitis Sicca in a Red Wolf (Canis rufus)}, volume={37}, ISSN={1042-7260 1937-2825}, url={http://dx.doi.org/10.1638/06-021.1}, DOI={10.1638/06-021.1}, abstractNote={Abstract A 12-yr-old intact male red wolf (Canis rufus) diagnosed with bilateral idiopathic dry eye was treated with subconjunctival drug delivery implants designed to release therapeutic levels of cyclosporine from 12–24 mo. Normal tear production and corneal health has been maintained, alleviating the need for daily handling of the animal for topical medication.}, number={4}, journal={Journal of Zoo and Wildlife Medicine}, publisher={American Association of Zoo Veterinarians}, author={Acton, Anne E. and Beale, A. Brady and Gilger, Brian C. and Stoskopf, Michael K.}, year={2006}, month={Dec}, pages={562–564} }