Melatonin as a therapeutic strategy against the alterations in the non image forming visual system induced by experimental glaucoma

DEVOUASSOUX, JULIÁN D.; IAQUINANDI A; ALTSCHULER, FLORENCIA; ROSENSTEIN, RUTH E; GONZÁLEZ FLEITAS, MARÍA F.; SANDE, PABLO H.

Carlos Paz, Provincia de Córdoba

Congreso; XXXIV Reunión Anual de la SAN; 2019

Sociedad Argentina de Investigación en Neurociencias

-MELATONIN AS A THERAPEUTIC STRATEGY AGAINST THE ALTERATIONS IN THE NON-IMAGE FORMING VISUAL SYSTEM INDUCED BY EXPERIMENTAL GLAUCOMAGlaucoma is a major cause of blindness, characterized by retinal ganglion cell (RGC) and optic nerve axon loss. A subset of RGCs expressing the photopigment melanopsin regulates non-image-forming (NIF) visual system functions, such as pupillary light reflex (PLR) and circadian rhythms. Glaucoma induces significant alterations in the NIF visual system. Our aim was to analyze the effect of melatonin on the NIF visual system alterations induced by glaucoma. Experimental glaucoma was induced in male Wistar rats by weekly intracameral injections of chondroitin sulfate (CS) for 10 weeks, while the contralateral eye received vehicle injections. One group of animals received a subcutaneous pellet of melatonin at 6 weeks of CS-treatment. Melatonin prevented the decrease in the blue and white light- evoked PLR, in melanopsin(+) RGC number, and in the anterograde transport from the retina to the olivary pretectal nucleus and the suprachiasmatic nucleus (SCN) induced by experimental glaucoma. Bilateral glaucoma significantly increased the light phase locomotor activity, and rhythm periodicity, whereas melatonin restored the locomotor activity daily rhythm. A significant decrease in light-induced c-Fos expression in the SCN was observed in glaucomatous animals, which was not evident in melatonin-treated animals. These results support the therapeutic role of melatonin against the NIF visual system alterations induced by glaucoma.