Three classical neuropathological changes in the brains of patients typically define AD: the accumulation of extracellular aggregated β-amyloid protein (to form senile plaques) and intracellular aggregation of hyperphosphorylated tau protein (to form neurofibrillary tangles), together with a severe loss of cholinergic innervation in the cerebral cortex [3]. This evidence concerns the gene MAPT and Alzheimer disease.