Neurotrophic factors and diseases of the nervous system.

Neuronal degeneration and death occur in mammals in the course of nervous system development, during senescence, and as a consequence of pathological events throughout life. Neurotrophic factors are natural target-derived molecules that prevent neuronal degeneration and death during development and promote neuronal recovery from injury and age-related atrophy. One neurotrophic factor--nerve growth factor-prevents the death of cells that are a target of varicella-zoster virus: dorsal root sensory neurons. Delivery of neurotrophic factors to dysfunctional neurons may be a useful therapeutic strategy for promoting neuronal recovery in a number of diseases, including varicella-zoster virus infection.