BDNF and Alzheimer disease: Clinical evidence and in vivo models have demonstrated that there is a reduction in expression and protein content of BDNF in Alzheimer’s disease transgenic mice and post-mortem brains of patients with Alzheimer’s disease (Phillips et al., 1991; Allen et al., 1999; Ferrer et al., 2000; Holsinger et al., 2000; Fumagalli et al., 2006; Peng et al., 2009).