Our interpretation of a reduced MT ratio due to heightened glial responses is further supported by histological studies in which ligature-induced periodontitis led to significant increases in Iba-1 immunoreactivity in the DG and thalamus regions, and GFAP immunoreactivity in the thalamus region of 3 × Tg-AD mice after ligature placement. This evidence concerns the gene AIF1 and periodontitis.