Physiological response of mouse retinal ganglion cells to electrical stimulation: effect of soma size.

An epiretinal prosthesis aims to restore functional vision by stimulating electrically the retinal ganglion cells (RGCs) in patients affected by photoreceptor degenerative diseases, such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP). During retinal degeneration, photoreceptor death is followed by pronounced remodeling and rewiring of inner retinal cells. Despite these changes, a considerable population of RGCs remain receptive to prosthetic stimulation. To target selectively a localized subset of RGCs, an improved understanding of the anatomical and physiological properties of these cells is required. Additionally, potential alterations in electrical excitability produced by the retinal degeneration needs to be assessed. This study investigates the effect of RGC soma size on the threshold for action potential (spike) generation and its implications for the rescue of visual function.