Neurotrophin-3 （NT-3） belongs to a family of growth factors called neurotrophins whose actions are centered in the nervous system. The neurotrophin family includes nerve growth factor （NGF）, brain-derived neurotrophic factor （BDNF）, neurotrophin-3 （NT-3）, neurotrophin-4/5 （NT-4/5）, neurotrophin-6（NT-6） and the recently cloned neurotrophin-7 Most of biological effects of neurotrophins are mediated by high affinity tyrosine kinase （Trk） receptors, although some of them require the binding to a low affini tyreceptor （p75LNTR）. NGF binds to TrkA receptors, BDNF preferentially activates TrkB receptors, while NT-3 mainly interacts with TrkC receptors, and at lower affinity with TrkB receptors.
NT-3 is structurally related to other neurotrophins like brain-derived neurotrophic factor. The expression of NT-3 starts with the onset of neurogenesis and continues throughout life. A wealth of information links NT-3 to the growth, differentiation, and survival of hippocampal cells as well as sympathetic and sensory neurons.