Evidence for a New G Protein-Coupled Cannabinoid Receptor in Mouse Brain

The purpose of these studies was to support the hypothesis that an undiscovered cannabinoid receptor exists in brain. [35S]GTPgS binding was stimulated by anandamide and WIN55212-2 in brain membranes from both CB1 1/1 and CB1 2/2 mice. In contrast, a wide variety of other compounds that are known to activate CB1 receptors, including CP55940, HU-210, and D9-tetrahydrocannabinol, failed to stimulate [35S]GTPgS binding in CB1 2/2 membranes. In CB1 2/2 mem-branes, SR141716A affected both basal and anandamide- or WIN55212-2-induced stimulation of [35S]GTPgS binding only a