Survival, growth and function of damaged cholinergic neurons.

Recent progress has been made in defining the requirements for survival, growth and function of damaged cholinergic neurons of the central nervous system. In particular, the responsiveness of cholinergic neurons to nerve growth factor (NGF) in the regulation of development, cell survival, axon elongation, and response to injury has led to the formulation of the Neurotrophic Hypothesis, a unifying hypothesis of neuronal responsiveness to growth-promoting substances. NGF-mediated effects on cholinergic neurons in culture as well as in the septum, basal nucleus, striatum, and hippocampus, and the ability of NGF to prevent lesion-induced cell death and to ameliorate the effects of aging, provide the foundation for this work. A potential role for glia and microglia in mediating the effects of NGF is proposed.