INS and Alzheimer disease: Local administration of STZ to the brain was shown to impair glucose metabolism (Hellweg et al. 1992; Hoyer 1998) and induce an insulin-resistant brain state, and therefore now is widely used as an animal model for Alzheimer’s disease (Steen et al. 2005; Salkovic-Petrisic et al. 2006; Grunblatt et al. 2007; Agrawal et al. 2011).