INS and diabetes mellitus: It has been shown in multiple AD mouse models (the 3xTg mouse model, App/PS1 mouse model, and SAMP8 mouse model) and in the Streptozotocin rat model, a diabetes model that develops AD-like symptoms, that both acute (1 to 2 weeks) and chronic (6 weeks) intranasal insulin treatment reduces amyloid-B levels and repairs insulin signaling through downregulation of tau kinases such as GSK-3β, and alleviates cognitive deficits associated with the models (Chen et al., 2014; Salameh et al., 2015; Mao et al., 2016; Guo et al., 2017).