Genetic deletion of mGluR5 increases locomotor, anxiety and explorative behaviours in wild-type and APPswe/PS1ΔE9 mice at 12 months of age. Graphs show (A) the total distance traveled, (B) the time spent in the centre quadrant of the open field and (C) number of rearings for wild-type (wt) and APPswe/PS1ΔE9 (APPswe) mice on either mGluR5+/+ or mGluR5-/- genetic backgrounds. (D) Show is the total distance traveled in the elevated plus maze. (E) Shown is the percentage of time spent in the open arm of the elevated plus maze. The number of animals tested: n = 16 for wt, n = 11 APPswe, n = 14 for mGluR5-/- and n = 14 for APPswe/mGluR5-/- mice. Data represent the mean ± SEM. The * indicates statistically significant (p < 0.05) differences between mice groups as compared with wild-type mice.