Experimental animal models of T2D show impairments in hippocampal-based memory performance [72], deficits in hippocampal neuroplasticity including decreases in dendritic spine density and neurogenesis [59] and decreases in synaptic transmission (LTP) [73], whereas bolstering insulin signaling mitigates β-amyloid-induced synapse loss in mature cultures of hippocampal neurons [72]. This evidence concerns the gene INS and type 2 diabetes mellitus.