CB1R-KO showed higher anxiety-like behavior than the WT. Administration of the CB1R antagonist AM251 increased anxiety-like behavior in WT but had no effect in the CB1R-KO. The CB agonist WIN-55,212-2 reduced anxiety-like behavior. The effect of WIN-55,212-2 was abolished by CB1-antagonist only in WT. This evidence concerns the gene CNR1 and Anxiety.