THE VISUAL RESPONSE OF RETINAL GANGLION-CELLS IS NOT ALTERED BY OPTIC-NERVE TRANSECTION IN TRANSGENIC MICE OVEREXPRESSING BCL-2

Attempts to rescue retinal ganglion cells from retrograde degeneration have had limited success, and the residual function of surviving neur ons is not known. Recently, it has been found that axotomized retinal ganglion cells die by apoptotic mechanisms. We have used adult transge nic mice overexpressing the Bcl-2 protein, a powerful inhibitor of apo ptosis, as a model for preventing injury-induced cell death in vivo. S everal months after axotomy, the majority of retinal ganglion cells su rvived and exhibited normal visual responses. In control wild-type mic e, the vast majority of axotomized retinal ganglion cells degenerated, and the physiological responses were abolished. These results suggest that strategies aimed at increasing Bcl-2 expression, or mimicking it s function, might effectively counteract trauma-induced cell death in the central nervous system. Neuronal survival is a necessary condition in the challenge for promoting regeneration and eventually restoring neuronal function.