CHARACTERIZATION OF THE SIGNALING INTERACTIONS THAT PROMOTE THE SURVIVAL AND GROWTH OF DEVELOPING RETINAL GANGLION-CELLS IN CULTURE

The signaling mechanisms that control the survival of CNS neurons are poorly understood. Here we show that, in contrast to PNS neurons, the survival of purified postnatal rat retinal ganglion cells (RGCs) in vi tro is not promoted by peptide trophic factors unless their intracellu lar cAMP is increased pharmacologically or they are depolarized by Kor glutamate agonists. Long-term survival of most RGCs in culture can be promoted by a combination of trophic factors normally produced alon g the visual pathway, including BDNF, CNTF, IGF1, an oligodendrocyte-d erived protein, and forskolin. These results suggest that neurotransmi tter stimulation and electrical activity enhance the survival of devel oping RGCs and raise the question of whether the survival control mech anisms of PNS and CNS neurons are different.