In addition to amyloid plaque and tau proteins, cholinergic neurons located in the basal forebrain are severely lost and degenerated due to alterations in presynaptic cholinergic terminals in the hippocampus and neocortex in AD, which are important for memory disturbances and other cognitive symptoms (Ferreira-Vieira et al., 2016). Here, MAPT is linked to Alzheimer disease.