Neurotrophin

Neurotrophins are a family of molecules that encourage survival of nervous tissue. Neurotrophic factors are secreted by cells in a neurons target field, and act by prohibiting the neuron from apoptosis. In this way, excess neurons are removed.

The neurotrophin family include nerve growth factors (NGF), Brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), and neurotrophin 4 (NT-4). There are two classes of receptors, p75 and the Tyrosine kinases. p75 is a low affinity neurotrophin receptor, to which all neurotrophins bind. The Tyrosine kinases include TrkA, TrkB, and TrkC, and will only bind with specific neurotrophins, but with a much higher affinity.

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