Fig. 8.

Multiple signaling pathways regulate the cell death pathway in sympathetic neurons. This schematic diagram depicts three points at which NGF can inhibit further progression of the cell death pathway. PI-3-K activity is required for NGF-dependent inhibition of c-Jun phosphorylation but is not required for inhibition of Bax translocation to the mitochondria or release of cytochromec from the mitochondria. MEK/MAPK does not account for any of these NGF-dependent events, and the signaling pathways required for these two events remain unknown.