Induction and Regulation of the Expression of NGF-Induced Genes in PC 12 Cells

Nerve growth factor (NGF) is a polypeptide that is necessary for the differentiation and survival of sympathetic and embryonic sensory neurons. The mechanism of action of NGF is poorly understood and the neuronal differentiation induced by NGF has been difficult to study because it has been impossible to maintain NGF-responsive neurons in vitro in the absence of growth factor. The PC12 cell line, derived from rat pheochromocytoma, responds to NGF and then converts from a replicating chromaffin-like cell into a nonreplicating sympathetic neuron-like cell. This NGF-mediated differentiation occurs slowly over a period of several days, requires RNA synthesis and results in the extension of neurites, the development of electrical exitability, increased level of acetylcholine receptors, etc. In contrast, NGF also induces some rapid changes in PC12 cells.