NEURONOTROPHIC EFFECT OF DEVELOPING OTIC VESICLE ON COCHLEOVESTIBULAR NEURONS - EVIDENCE FOR NERVE GROWTH-FACTOR INVOLVEMENT

In the developing inner ear, the existence of a neuronal death and of a peripheral target-derived trophic effect on cochleovestibular neurons has been documented. Using cultures of rat cochleovestibular neurons, we show that the E12 otic vesicles releases a factor promoting the survival and the neuritogenesis of these neurons, and that this effect is mimicked by NGF. The effect of the otic vesicle conditioned medium (OVCM) on cochleovestibular neurons is suppressed by anti-NGF antibodies. OVCM is neuronotrophic for NGF-sensitive sympathetic neurons, an effect that is also suppressed by anti-NGF antibodies, further demonstrating the presence of biologically active nerve growth factor. © 1990.