Changes in the Inner Retinal Cells after Intense and Constant Light Exposure in Sprague ‐Dawley Rats

AbstractLight insult causes photoreceptor death. Few studies reported that continuous exposure to light affects horizontal, M üller and ganglion cells. We aimed to see the effect of constant light exposure on bipolar and amacrine cells. Adult Sprague‐Dawley rats were exposed to 300 or 3000 lux for 7 days in 12‐hour light: 12‐hour dark cycles (12L:12D). The latter group was then exposed to 24L:0D for 48 hours to indu ce significant damage. The same animals were reverted to 300 lux and reared for 15 days in 12L:12D cycles. They were sacrificed on different days to find the degree of retinal recovery, if any, from light injury. Besides photoreceptor death, continuous light for 48 hours resulted in downregulation o f parvalbumin in amacrine cells and recoverin in cone bipolar cells (CBC). Rod bipolar cells (RBC) maintained an unaltered pattern of PKC‐α expression. Upon reversal, there were increased expressions of parvalbumin in amacrine cells and recoverin in CBC, while RBC showed an increasing trend of PK C‐α expression. The data show that damage in bipolar and amacrine cells after exposure to intense, continuous light can be ameliorated upon reversal to normal LD cycles to which the animals were initially acclimated to.
Source: Photochemistry and Photobiology - Category: Science Authors: Tags: RESEARCH ARTICLE Source Type: research