To promote understanding of the pathogenesis of cognitive impairment or dementia, we explored the potential interaction between transient cerebral ischemia and amyloid-β (Aβ) infusion in mediating cognitive decline and examined the possible ameliorative effect of angiotensin II type 2 (AT2) receptor activation in vascular smooth muscle cells (VSMC) on this cognitive deficit. The gene discussed is AGTR2; the disease is dementia.