The article provides a comprehensive overview of brain-derived neurotrophic factor (BDNF), a key member of the neurotrophic family of proteins. BDNF was discovered in 1982 and has since been shown to play crucial roles in brain development, physiology, and pathology. The gene encoding BDNF is located on chromosome 11p and consists of four 5' exons and one 3' exon. BDNF shares about 50% amino acid identity with other neurotrophins and is produced as a proprotein that is cleaved to the mature form. BDNF binds to trk receptors, which are members of the receptor tyrosine kinase family, and to the p75 receptor, which is related to the tumor necrosis factor superfamily. BDNF signaling involves the activation of various intracellular signaling cascades, including the Ras-MAP kinase cascade and the activation of PLC-γ1, p85, and Shc. BDNF gene expression is regulated by various stimuli, including neural activity, and is involved in the development of the visual cortex and the regulation of dendritic morphology. BDNF also plays a role in synaptic transmission, where it strengthens excitatory synapses and weakens inhibitory synapses. Additionally, BDNF enhances neurogenesis and is involved in learning and memory, particularly in the hippocampus. In pathological conditions, elevated levels of BDNF may contribute to epilepsy and chronic pain sensitization. BDNF has also been implicated in neurodegenerative diseases such as Alzheimer's and Parkinson's disease, and in neuropsychiatric disorders like depression and bipolar disorder. The article concludes by discussing the potential therapeutic applications of BDNF in treating these conditions.The article provides a comprehensive overview of brain-derived neurotrophic factor (BDNF), a key member of the neurotrophic family of proteins. BDNF was discovered in 1982 and has since been shown to play crucial roles in brain development, physiology, and pathology. The gene encoding BDNF is located on chromosome 11p and consists of four 5' exons and one 3' exon. BDNF shares about 50% amino acid identity with other neurotrophins and is produced as a proprotein that is cleaved to the mature form. BDNF binds to trk receptors, which are members of the receptor tyrosine kinase family, and to the p75 receptor, which is related to the tumor necrosis factor superfamily. BDNF signaling involves the activation of various intracellular signaling cascades, including the Ras-MAP kinase cascade and the activation of PLC-γ1, p85, and Shc. BDNF gene expression is regulated by various stimuli, including neural activity, and is involved in the development of the visual cortex and the regulation of dendritic morphology. BDNF also plays a role in synaptic transmission, where it strengthens excitatory synapses and weakens inhibitory synapses. Additionally, BDNF enhances neurogenesis and is involved in learning and memory, particularly in the hippocampus. In pathological conditions, elevated levels of BDNF may contribute to epilepsy and chronic pain sensitization. BDNF has also been implicated in neurodegenerative diseases such as Alzheimer's and Parkinson's disease, and in neuropsychiatric disorders like depression and bipolar disorder. The article concludes by discussing the potential therapeutic applications of BDNF in treating these conditions.