Species Differences in the Nutrition of Retinal Ganglion Cells among Mammals Frequently Used as Animal Models

Abstract

The diffusion rate for proper nutrition of the inner retina depends mainly on four factors which are discussed in this review: 1. The diffusion distance between blood and retinal ganglion cells shows morphological variants in different mammalian species, namely a choroidal nutrition type, a retinal nutrition type, and a mixture of both types. 2. Low oxygen concentration levels in the inner retina force the diffusion of oxygen especially in the choroidal nutrition type. Other nutrients might be supplied by surrounding cells, mainly Müller cells. 3. Diffusion in the eye is influenced by the intraocular pressure, which is vital for the retinal ganglion cells but might also influence their proper function. Again, the nutrition types established might explain the differences in normal intraocular pressure levels among different species. 4. Temperature is a critical feature in the eye which has to be buffered to avoid neuronal damage. The most effective buffer system is the increased blood turnover in the choroid which has to be established in all species.

Molecular Biology of Retinal Ganglion Cells

“…In a review article, May [ 1 ] summarizes factors that majorly determine the diffusion efficiency of nutrients between supplying blood vessels and inner retinal neurons including RGCs. It has been put forward that three basic types of nutrition supply mechanisms exist, namely the choroidal nutrition type, a retinal nutrition type, and a mixture of these two.…”