背景资料：BDNF is a member of the family of neurotrophic factors. It was first explored and purified from pig brain in 1982, and other members of the neurotrophin family were successively discovered. BDNF is induced by cortical neurons, and is necessary for survival of striatal neurons in the brain. Expression of BDNF is reduced in both Alzheimer's and Huntington disease patients. It participates in axonal growth, pathfinding and in the modulation of dendritic growth and morphology. It also plays a role in the regulation of stress response and in the biology of mood disorders. The BDNF gene is rather complex in its structure and it can express four different mRNA isoforms by alternative splicing, producing 28-37 kDa proteins.