Bdnf

Brain-Derived Neurotrophic Factor (BDNF) is a protein that, in humans, is encoded by the BDNF gene. BDNF is a member of the neurotrophin family of growth factors, which are related to the canonical nerve growth factor (NGF). Neurotrophic factors are found in the brain and the peripheral nervous system.

Structure

BDNF is a small dimeric protein, consisting of 247 amino acids. It is synthesized as a precursor protein, proBDNF, which is cleaved to produce the mature BDNF protein. The mature form of BDNF is a homodimer, meaning it consists of two identical subunits. The structure of BDNF is characterized by a cystine knot motif, which is a common feature of the neurotrophin family.

Function

BDNF plays a crucial role in the development and maintenance of the nervous system. It is involved in the survival, growth, and differentiation of neurons during development. In the adult brain, BDNF is important for synaptic plasticity, which is essential for learning and memory. BDNF supports the survival of existing neurons and encourages the growth and differentiation of new neurons and synapses.

Role in Synaptic Plasticity

BDNF is a key regulator of synaptic plasticity, particularly in the hippocampus, a region of the brain associated with memory and learning. It enhances long-term potentiation (LTP), a process that strengthens the connections between neurons and is considered a cellular mechanism underlying learning and memory.

Neurogenesis

BDNF is also involved in neurogenesis, the process by which new neurons are formed in the brain. This process is particularly active in the dentate gyrus of the hippocampus. BDNF promotes the survival and integration of new neurons into existing neural circuits.

Expression

BDNF is widely expressed in the central nervous system, including the cortex, hippocampus, and basal forebrain, areas vital for learning, memory, and higher thinking. It is also found in the peripheral nervous system, where it supports the survival of sensory neurons.

Regulation

The expression of BDNF is regulated by various factors, including physical activity, stress, and diet. Exercise has been shown to increase BDNF levels, which is associated with improved cognitive function and mood. Conversely, chronic stress can decrease BDNF expression, which may contribute to depression and other mood disorders.

Clinical Significance

BDNF has been implicated in a variety of neurological and psychiatric disorders.

Depression

Reduced levels of BDNF have been associated with major depressive disorder (MDD). Antidepressant treatments, including selective serotonin reuptake inhibitors (SSRIs), have been shown to increase BDNF levels, which may contribute to their therapeutic effects.

Neurodegenerative Diseases

BDNF is also involved in neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. In Alzheimer's disease, decreased BDNF levels are associated with cognitive decline. Enhancing BDNF signaling is being explored as a potential therapeutic strategy for these conditions.

Schizophrenia

Alterations in BDNF expression and signaling have been observed in schizophrenia, suggesting a role in the pathophysiology of the disorder.

Therapeutic Potential

Given its role in neuroplasticity and neuroprotection, BDNF is a target for therapeutic interventions in various neurological and psychiatric conditions. Strategies to increase BDNF levels or mimic its activity are being investigated for their potential to treat these disorders.

See Also

• Neurotrophin
• Nerve growth factor
• Synaptic plasticity
• Neurogenesis

External Links

• BDNF Gene - NCBI
• BDNF Protein - UniProt