Similar results were seen in several previous studies of both T1DM and T2DM animal models.32, 33 Since GFAP−/− mice appeal to impairment of LTP, imbalance of glutamate‐glutamine cycle, abnormal BBB, and demyelization, it has confirmed the importance of GFAP for the normal function of astrocytes that maintain and protect neurons.34, 35, 36 Therefore, the decrease of GFAP in KK‐Ay mice might play a role in cognitive dysfunction. Here, GFAP is linked to type 2 diabetes mellitus.