INS and Alzheimer disease: Moreover, AD brains often exhibit impaired insulin receptors activity (Frölich et al., 1998; Talbot et al., 2012), attenuated levels of insulin and insulin growth factor 1 as well as decreased levels of downstream proteins such as insulin receptor substrate 1 (Rivera et al., 2005; Moloney et al., 2010; Talbot et al., 2012).