Effects of light on the development of melanoposin containing retinal ganglion cells in rats

F.-M. Guo, A.-J. Zhou, N. Zhang, H.-H. Chen, L.-Y. Zhu

Department of Medical Sciences, Jinhua Polytechnic, Jinhua, Zhejiang Province, China. jhyxysys@126.com

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• Ophthalmology

OBJECTIVE: The present study was planned to evaluate the effect of light on the development of light-sensitive retinal ganglion cells.

MATERIALS AND METHODS: The Sprague-Dawley (SD) rats were segregated into 3 groups (n=18) which included routine feeding 10-day group 1, routine feeding 14-day group 2 and light-deprivation feeding 14-day group 3. The group 1 animals were routinely fed for 10 days in normal light conditions and were sacrificed for analyses on day 10. Similarly, group 2 animals were routinely fed for 14 days in normal light conditions and were sacrificed for analyses on day 14. The group 3 animals were kept were routinely fed for 7 days which was followed by their feeding in a light-deprived conditions and were sacrificed on day 14.

RESULTS: The expression of the opsin gene determined by real-time PCR in retinal tissues showed a significant decline in the light-deprived group 3 when compared to other two groups. Furthermore, the melanopsin protein also showed a significant decline in its protein expression in light-deprived group 3 as observed by immune-blot analyses. The immuno-fluorescence analyses also showed the similar trend confirming the effect of light on the development of retinal ganglion cells.

CONCLUSIONS: Light is essential for the proper development process of retinal ganglion cells as light directly affects regulatory opsin gene expression.

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