Experimental animal models of type 2 diabetes show impairments in hippocampal-based memory performance (Li et al., 2002; Winocur et al., 2005), deficits in hippocampal neuroplasticity including decreases in neuronal spine density and neurogenesis (Stranahan et al., 2008) and decreases in synaptic transmission (Kamal et al., 2013), whereas bolstering insulin signaling mitigates Aβ-induced synapse loss in mature cultures of hippocampal neurons (De Felice et al., 2009). This evidence concerns the gene INS and type 2 diabetes mellitus.