BDNF and Alzheimer disease: Moreover, according to previous AD animal experiments, rTMS reversed the loss of hippocampal nerve growth factor and BDNF that induced by amyloidβ-protein 42(Aβ42), increased the affinity of BDNF to TrkB in the prefrontal cortex, enhanced hippocampal LTP, and reduced hippocampal β-amyloid precursor protein(APP) [29–31].