Recent advances in understanding context-dependent mechanisms controlling neurotrophin signaling and function

<ns4:p>Complex mechanisms control the signaling of neurotrophins through p75<ns4:sup>NTR</ns4:sup> and Trk receptors, allowing cellular responses that are highly context dependent, particularly in the nervous system and particularly with regard to the neurotrophin brain-derived neurotrophic factor (BDNF). Recent reports describe a variety of sophisticated regulatory mechanisms that contribute to such functional flexibility. Mechanisms described include regulation of trafficking of alternative BDNF transcripts, regulation of post-translational processing and secretion of BDNF, engagement of co-receptors that influence localization and signaling of p75<ns4:sup>NTR</ns4:sup> and Trk receptors, and control of trafficking of receptors in the endocytic pathway and during anterograde and retrograde axonal transport.</ns4:p>