The role of brain-derived neurotrophic factor (BDNF) and the effects of exercise

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family of growth factors and found in the nervous system and periphery. BDNF is known to promote the growth, development, maintenance of functions, and survival of the neuronal system. In addition, accumulating evidences suggest that BDNF may play important roles in memory, learning, mood disorder, food intake, and energy metabolism. Recently, decreased level of BDNF in the brain and blood has been reported in the patients with depression or Alzheimer’s disease. On the other hand, exercise increased the expression of brain BDNF and its receptor (high-affinity tyrosine protein kinase receptor; TrkB), which mediated the improvement of memory and learning in rodents. Moreover, administration of BDNF to the diabetic obese mice suppressed the weight gain and improved the glucose metabolism. Those evidences raise the possibility that exercise contributes to the prevention or improvement of dementia, depression and diabetes through BDNF-trkB pathway. In this paper, we summarized the functions of BDNF and also reviewed the effects of exercise on BDNF especially focused on