Tell me how you live, and I will tell you if your retina will be damaged: impact of the environment on the retina´s health

DORFMAN D

Congreso; 16th International Congress on Photobiology; 2014

Ischemia is a key component of several retinal diseases that are leading causes of irreversible blindness. At present, there are no effective strategies for the treatment of retinal ischemic damage. Recent evidences indicate that environment conditions influence the visual system function. Enriched environment (EE) constitutes a strategy that boosts exploratory, visual, and cognitive activities, social interaction and voluntary physical exercise. In this context, the aim of the present work was to analyze the effect of EE housing against retinal damage induced by ischemia.  Adult male Wistar rats were exposed to a standard environment (SE) or EE after retinal ischemia for 3 weeks. EE consisted of big cages, housing 6 animals and containing several food hoppers, wheels and different objects repositioned once/day and fully substituted once/week. Retinal ischemia was induced by increasing intraocular pressure to 120 mm Hg for 40 min. Retinal function was weekly analysed and retinal morphology was analysed 3 weeks post-ischemia. Macroglial reactivity (glial fibrillary acidic protein, GFAP) and synaptophysin expression were assessed by immunohistochemistry. Anterograde transport from the retina to the superior colliculus (SC) was examined after an intravitreal injection of cholera toxin b-subunit.   In control animals, ischemia induced a significant decrease in retinal function, whereas EE housing completely avoided these alterations. In SE-housed animals, ischemia induced a significant retinal ganglion cell loss, an increase in GFAP levels in Müller cells, and reduced immunoreactivity for synaptophysin, which were prevented by EE housing. In control animals, ischemia induced a deficit in the anterograde transport from the retina to the superior colliculus, which was recovered by EE exposure.  These results suggest that the exposure to an EE could become a new strategy for retinal ischemia treatment.