Figure 4.

The behavioral effects of anandamide in FAAH^−/− mice are mediated by the CB₁ cannabinoid receptor. The effect of vehicle (open bars) or SR141716A (filled bars) administered 10 min before treatment with anandamide in FAAH^−/− mice. SR141716A (10 mg/kg) completely blocked the hypomotility (A), antinociception (B), catalepsy (C), and hypothermia (D) induced by anandamide (50 mg/kg), as SR141716A-pretreated, anandamide-treated FAAH^−/− mice were indistinguishable in all behavioral assays from FAAH^−/− mice treated with vehicle alone (0 mg/kg anandamide data in Fig. 2 A–D). **, P < 0.01 and ***, P < 0.001 for SR141716A-treated versus vehicle-treated FAAH^−/− mice (planned comparison). The results are presented as means ± SE. n = 6–8 mice per group.