Neurotrophin 3 (NT-3), also known as hippocampus-derived neurotrophic factor (HDNF), is a member of the neurotrophin family. It shares high structural homology to nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin 4 (NT-4), but they all operate via different high-affinity membrane receptors and differ in target specificity. Expression of NT-3 has been detected in neurons of the central nervous system like the hippocampus and cerebellum. Furthermore it is expressed in muscles. NT-3 promotes the survival and differentiation of existing neurons and supports the growth and differentiation of new nerve and glial cells. It has been shown to bind and activate the TrkC tyrosine receptor kinase. The activities of NT-3 and BDNF are additive in some systems. The amino acid sequence of human and mouse NT-3 is identical.
