Fig. 1.

Spontaneous locomotor activity during a two-hour period in a novel home cage environment. (a) GRM2^−/− mice were initially hyperactive but then their activity levels fell below those of the WT mice for most of the 2nd hour of recording. n = 15 WT; n = 14 GRM2^−/−. (b) GRM3^−/− mice showed similar activity levels compared to WT controls, although the temporal profile across the session was subtly altered. n = 15 WT; n = 15 GRM3^−/−. Data are mean beam breaks ± SEM for each block of 10 min, and were analysed using a two way, repeated measures ANOVA, followed by analysis of simple main effects. Asterisks indicate statistical significance at p < 0.05 from analysis of simple main effects.