Genetic deletion of mGluR5 rescues spatial memory deficits in APPswe/PS1ΔE9 mice at 9 and 12 months of age. Shown are the swim speeds at (A) 9 and (B) 12 months of age, escape latencies, at (C) 9 and (D) 12 months of age, and path lengths (E) at 9 and (F) 12 months of age for wild-type (wt) (n = 16), APPswe/PSΔE9 (APPswe) (n = 11), mGluR5-/- (n = 14), and APPswe/mGluR5-/- (n = 14) mice recorded during the acquisition phase in the Morris Water Maze test for spatial learning. Shown is the time that wt, APPswe, mGluR5-/-, and APPswe/ mGluR5-/- mice spent in the target quadrant during the probe trial at (G) 9 and (H) 12 months of age. Data represent the mean ± SEM. Statistically significant * (p < 0.01) and ** (p < 0.001) differences between mice groups when compared to wild-type mice. Statistical significance was assessed by repeated measures ANOVA.