Neurotrophins and p75NTR in Axonal Regeneration and Myelination

The neurotrophins are powerful, secreted signaling molecules that regulate the survival, proliferation, and function of neural cells. Neurotrophin-dependent signaling is not only critical during neurodevelopment but also plays an important role in the adult, where it mediates processes of plasticity and repair in both the central and peripheral nervous systems. The roles that the four known neurotrophins and their receptors play in regulating the cellular processes required for repair has been the subject of a significant body of research and has produced several promising avenues for treatment. This chapter reviews the current understanding of Neurotrophin-dependent signaling and how this evolving understanding can facilitate the development of future strategies to address neurodegeneration and neurotrauma. Of particular interest in this context is the p75 pan-neurotrophin receptor, a mercurial molecule that binds not only the neurotrophins but also the other neurotrophin receptors in order to modulate these signaling cascades. P75-dependant signaling has been shown to be essential in the regulation of processes such as neurite outgrowth, axonal regeneration, cell survival, cellular proliferation, and myelination; these processes are critical to successful neural repair. As we learn more about the neurotrophins and p75 through future research, novel therapeutic targets for the treatment of damage to the nervous system will continue to be revealed.