Contradictory, in another ICV-STZ rat model, AD-like abnormalities were associated with increased GSK3α/β-Ser21/9 phosphorylation, while disease amelioration following the intranasal application of insulin (indicated by improved learning and memory, reduced tau phosphorylation, and microglia activation) occurred in the presence of increased GSK3α/β activity [173]. Here, MAPT is linked to Alzheimer disease.