Brain-derived neurotrophic factor and physical activity: A review

The review focuses on one of the brain-derived neurotrophic factors (BDNF) and its role in human physical activity. BDNF is a protein found in many areas of the brain including, e.g., the hippocampal cortex. The paper provides evidence that BDNF is instrumental in the development (e. g., in cell differentiation, cell migration to a specific location, growth of dendrites, synaptogenesis), survival and maintenance of neuron activity. The paper describes the mechanisms of BDNF synthesis. It is shown that this neurotrophic factor is present in microglial cells, lymphocytes, monocytes, and skeletal muscle cells. It can also cross the blood-brain barrier. It is a critical component in the origin of long-term potentiation-related changes in synapses. BDNF helps maintain high levels of concentration and attention and may play a role in protecting the brain from damage. Decreased blood levels of BDNF in newborns may increase the risk of developing ASD, ADHD, post-traumatic stress disorder, and bipolar disorder. Learning and memory processes are associated with structural changes in dendritic spines in the hippocampus, cortex, and amygdala, and BDNF modulates the number and structure of dendritic spines both during the development and in the adult brain. Physical activity increases the level of BDNF in several ways. One of these mechanisms is associated with lactate, which appears as a result of human physical activity, and is also the most important signaling molecule. The higher the lactate level, the higher the BDNF level. The improvement in cognitive function after physical activity has also been attributed to high serum levels of BDNF.