Synthesis and role of melatonin in the retina of rodents
Abstract : Melatonin, a major hormonal "Zeitgeber" in the body, is produced in the pineal gland as well as the retina. In mammals its regulation and functions in this tissue are only partially understood. The aim of my project was to characterize the temporal and spatial expressions of melatonin as well as its potential roles in retinal physiopathology. In the first part, we identified the timing and sites of melatonin production. Notably, nocturnal synthesis occurs in the cones while diurnal production is seen in the ganglion cells. Our work also establishes that melatonin can act via its MT1-type receptors localized in the three retinal nuclear layers. The second axis demonstrated that melatonin increases photoreceptors viability via its receptors during the course of aging by modulating activation of an intracellular survival pathway.