Brain-derived neurotrophic factor (BDNF) is a member of the growth factor neurotrophin family, closely related to nerve growth factor. Neurotrophic factors are present in both the brain and peripheral tissues. BDNF is synthesized and processed in the endoplasmic reticulum and secreted by dense core vesicles. It is active in regions such as the hippocampus, cortex, and basal forebrain in the brain, as well as expressed in the retina, motor neurons, kidneys, salivary glands, and prostate. BDNF acts on certain neurons in the central and peripheral nervous systems, promoting the survival of existing neurons and facilitating the growth and differentiation of new neurons and synapses.Changes in BDNF have been implicated in the pathogenesis of schizophrenia and are associated with conditions such as depression, eczema, epilepsy, Alzheimer’s disease, obesity, aging, congenital central hypoventilation syndrome, and chemotherapy-induced cognitive dysfunction.