Tropomyosin kinase receptor B (TrkB), also known as tyrosine kinase receptor B, is a receptor for brain-derived neurotrophic factor (BDNF) and a member of the neurotrophic factor tyrosine kinase receptor (NTRK) family. This kinase is a membrane-bound receptor that is only expressed in neurons of the central nervous system. TrkB mediates many of the functions of neurotrophic factors such as BDNF, neurotrophic factor-4 (NT-4), and neurotrophic factor-3 (NT-3), including neuronal differentiation and survival. In the extracellular domain, it has two distinct regions that bind BDNF with high affinity. Upon binding to neurotrophic factors, TrkB itself and downstream molecular members of related signaling pathways are phosphorylated. TrkB plays an important role in tumorigenesis and metastasis, and mutations in this gene have been linked to obesity and mood disorders. Therefore, BDNF/TrkB signaling is considered as a potential target for the treatment of schizophrenia.