Purchase this article with an account.
A. Ray, E.-J. Lee, L. L. Chan, M. S. Humayun, J. D. Weiland; Effect of High Charge Stimulation on Retinal Morphology. Invest. Ophthalmol. Vis. Sci. 2009;50(13):4572.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the effect of high charge stimulation on the morphology of retina.
A disk electrode (75 µm diameter Pt/Ir) was inserted into the vitreous cavity of adult Copenhagen pigmented rats. Electrode placement in close proximity to the retina was achieved by measuring the electrode impedance while advancing the electrode towards the retina. At this location, the electrode was held in position and cathodic-first, charge-balanced, biphasic current pulses of 0.68mC/cm2 were delivered to the retina at 2 Hz for a 1-hour period. The return electrode was inserted in the skin next to the nose. At the end of stimulation, animals were given a recovery period of either 3 (n=4), 7 (n=2) or 14 days (n=2). Control experiments were also carried out where in the electrode was positioned the same way as described above and held passively in position for 1-hour period. Animals received a post-surgical recovery period of either 3 (n=1), 7 (n=2) or 14 days (n=1), after which they were sacrificed for immunohistochemical analysis.
The only observed change in retinae stimulated at 0.68mC/cm2 was the upregulation of the glial fibrillary acidic protein (GFAP). Gliosis was observed over the entire retina undergoing stimulation. No obvious difference in the GFAP expression was observed across the different recovery periods. No gliosis was noted in the control eyes. Immunohistochemical analysis revealed normal morphology of the major cell types in the retina viz., photoreceptor cells, ON bipolar cells, horizontal cells, AII amacrine cells and ganglion cells. In addition SV2B immunoreactivity showed normal expression of the synaptic vesicles both at the outer and inner plexiform layer. Double exposure of SV2B with GO revealed dendrites of ON bipolar cells in close contact with the synaptic vesicles of photoreceptors at the outer plexiform layer similar to normal retina. Immunoreactivity towards the glutamate transporter (GLAST) found in Müller cells also showed expression similar to normal retina.
This PDF is available to Subscribers Only