Brain Derived Neurotrophic Factor or BDNF is a neurotrophin that is part the trophin family of proteins. [1]
The trophin family is composed of four structurally related proteins with similar functions in promoting neurite outgrowth and enhancing neuronal survival in the central and peripheral nervous systems. Signaling of each neurotrophin is mediated through a specific Trk family receptor tyrosine kinase (Trk A, Trk B and Trk C). BDNF is widely expressed throughout the central and peripheral nervous systems beginning in early development and extending over the entire life cycle. BDNF is known to play a key role in early embryogenesis by enhancing the differentiation of neuronal precursors. In the mature central nervous system, BDNF protein and its receptor, Trk B, are most abundantly expressed in the hippocampus and hypothalamus.