Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family, which includes nerve growth factor (NGF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5). BDNF plays a crucial role in brain development, physiology, and pathology. It is essential for synaptic plasticity, which underlies learning and memory. BDNF is involved in the survival and growth of neurons, particularly in the hippocampus and neocortex. It also contributes to neurogenesis, the formation of new neurons, in regions such as the olfactory bulb, striatum, septum, and thalamus. BDNF is implicated in various neurological and psychiatric disorders, including epilepsy, chronic pain, Alzheimer's disease, Parkinson's disease, and bipolar disorder. It modulates synaptic transmission by strengthening excitatory synapses and weakening inhibitory synapses. BDNF signaling is mediated through Trk receptors and the p75NTR receptor, leading to various intracellular signaling pathways. BDNF is also involved in pain transduction and has been shown to influence mood and depression. BDNF levels vary with physiological and pathological states, and its expression is regulated by various stimuli, including neural activity, light, and physical exercise. BDNF has potential therapeutic applications in neurodegenerative diseases and neuropsychiatric disorders.Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family, which includes nerve growth factor (NGF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5). BDNF plays a crucial role in brain development, physiology, and pathology. It is essential for synaptic plasticity, which underlies learning and memory. BDNF is involved in the survival and growth of neurons, particularly in the hippocampus and neocortex. It also contributes to neurogenesis, the formation of new neurons, in regions such as the olfactory bulb, striatum, septum, and thalamus. BDNF is implicated in various neurological and psychiatric disorders, including epilepsy, chronic pain, Alzheimer's disease, Parkinson's disease, and bipolar disorder. It modulates synaptic transmission by strengthening excitatory synapses and weakening inhibitory synapses. BDNF signaling is mediated through Trk receptors and the p75NTR receptor, leading to various intracellular signaling pathways. BDNF is also involved in pain transduction and has been shown to influence mood and depression. BDNF levels vary with physiological and pathological states, and its expression is regulated by various stimuli, including neural activity, light, and physical exercise. BDNF has potential therapeutic applications in neurodegenerative diseases and neuropsychiatric disorders.