To assess the accumulation of NFTs during the course of the disease, sagittally cut brain hemispheres were collected from female and male 6-, 12-, 15-, 18-, and 21-month-old 3xTg-AD mice (oldest age dependent upon survival) (n = 3–8 mice of each sex per age group) and stained with a phospho-tau (Ser202, Thr205) antibody (AT8). Here, MAPT is linked to Alzheimer disease.