GRM5 and Alzheimer disease: Consistent with these observations, we have recently shown that the genetic deletion of mGluR5 in APPswePS1ΔE9 mice also results in the reversal of the cognitive deficits associated with this mouse model of AD at both 9 and 12 months of age, and that soluble Aβ oligomer levels and Aβ plaques in APPswePS1ΔE9 mice are reduced in the absence of mGluR5 expression at 12 month of age [12].