CNR1 and major depressive disorder: In the present study, based on the involvement of TRPV1 receptors in the effects of CB1 ligands, the functional relationship between nAChRs and TRPV1 receptors [32], and the author's preliminary data on the antidepressant-like effects of some cannabimimetics against NC-induced depression-like behaviors [10], the effects of TRPV1 ligands with or without affinity for CB1 receptors were examined against NC- and IM-induced depression-like behaviors in mice.