Role of neurotrophic factors in neuronal development.

The spectrum of potential biological roles for neurotrophic factors in development and maturation of the nervous system continues to widen. Careful analysis of the phenotypes of knock-out mice has been used to test directly the 'neurotrophic hypothesis', and the role of members of the transforming growth factor beta superfamily--in particular, glial cell line derived neurotrophic factor--in regulating neuronal survival has become apparent. The effects of neurotrophin-3 on early neuronal differentiation and maturation have proved to be both multiple and complex. Neurotrophic factors are also emerging as potential regulators of synapse stabilization and function.