INTRARETINAL NEUROTROPHIC ACTIVITY PREVENTS THE DEGENERATION OF GANGLION-CELLS IN RETINAL EXPLANTS

The degeneration of ganglion cells was studied in neural retina explan ted from the eyes of newborn rats. The ganglion cells were detected by the presence of retrogradely transported horseradish peroxidase injec ted into the superior colliculus. The time course of cell death among the axotomized ganglion cells in the explants was similar to that foun d in vivo after axotomy in neonatal rats. The effect of culture media conditioned with retinal cells froin either newborn rats or chick embr yos was tested on the survival of ganglion cells in the explants. Both conditioned media increased 2- to 3-fold the survival of rat retinal ganglion cells after 2 days in culture. The data show that soluble tro phic factors released by retinae of distinct species can influence the survival of ganglion cells within their histotypic microenvironment.