NEUROTROPHIN REGULATION OF GENE-EXPRESSION

The neurotrophins comprise a family of secreted proteins that elicit p rofound responses in cells of the developing and mature vertebrate ner vous system including the regulation of neuronal survival and differen tiation. The molecular mechanisms by which the neurotrophins exert the ir effects have been the subject of intense investigation. The neurotr ophins elicit responses in neurons via members of the Trk family of re ceptors and the p75 neurotrophin receptor. Once activated, neurotrophi n receptors trigger a large number of biochemical events that propagat e the neurotrophin signal from the plasma membrane to the interior of the cell. An important target of the neurotrophin-induced signaling pa thways is the nucleus, where neurotrophin-induced signals are coupled to alterations in gene expression. These neurotrophin-induced changes in gene expression are critical for many of the phenotypic effects of neurotrophins including the regulation of neuronal survival and differ entiation.