Cerebellar granule cell survival and maturation induced by K+ and NMDA correlate with c-fos proto-oncogene expression.

Persistent depolarization with a high K+ concentration (30 mM) or sustained activation of N-methyl-D-aspartate (NMDA) receptors (12.5 mM K+ plus 100 microM NMDA) enhance both survival and maturation of mouse cerebellar granule neurons in vitro taking as criteria the amount of protein and DNA and the release of endogenous glutamate respectively. K+ and NMDA neurotrophic effects are associated with c-fos protein expression in the nucleus of these cells suggesting that c-fos protein could play a role in the survival and/or maturation of granule neurons.