MAPT and Alzheimer disease: Although apparently lacking neurofibrillary tangles (one of the pathological hallmarks of AD), SAMP8 mouse brain shows many neuropathological signatures of AD, including APP overproduction, abnormal Aβ accumulation and impaired Aβ clearance, hyperphosphorylation of tau protein, increased oxidative stress, and gliosis, especially in the hippocampus (Pallas et al., 2008; Morley et al., 2012; Akiguchi et al., 2017).