Abstract
Complex mechanisms control the signaling of neurotrophins through p75 (NTR) 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 (NTR) and Trk receptors, and control of trafficking of receptors in the endocytic pathway and during anterograde and retrograde axonal transport.