Role of BDNF in central motor structures and motor diseases.

Brain-derived neurotrophic factor (BDNF), belonging to the neurotrophic family of growth factors, has a widespread distribution in the central and peripheral nervous systems. In central motor structures including the motor cortex, cerebellum, basal ganglia, and spinal cord, BDNF exerts both neurotrophic and direct electrophysiological effects via a high-affinity tyrosine receptor kinase B receptor and a common low-affinity p75 neurotrophin receptor. The underlying signaling pathways mainly involve mitogen-activated protein kinase cascades, phosphatidylinositol 3-kinase pathway, and phospholipase C-γ pathway. The loss of BDNF usually leads to neurodegeneration in these motor centers and eventually results in several severe motor diseases, such as amyotrophic lateral sclerosis, spinocerebellar ataxias, Parkinson's disease, Huntington's disease, as well as vestibular syndrome. In this review, we summarize the recent understanding of functions of BDNF in motor structures and suggest that BDNF may be a potent candidate for the treatment of these neurodegenerative motor diseases.