MAPT and Alzheimer disease: Since the earliest accumulation of non-fibrillar tau (recognized by the MC1 antibody) is not present in 3xTg AD mice until around 9-months-of-age in CA1 (Supplementary Figure S11; Supplementary Table S3), we overexpressed human tau in LEC layer II (an area that is early involved in NFT deposition in AD patients), of 6 months-old 3xTg AD mice (Figure 2A).