Heterotrimeric G protein-coupled receptor for endocannabinoid 2-arachidonoylglycerol mediating inhibition of adenylate cyclase. May function in inflammatory response, nociceptive transmission and bone homeostasis. Localizes to apical dendrite of pyramidal neurons. Expressed by cells of hematopoietic origin. Expressed in skin in suprabasal layers and hair follicles, in brain by neurons and glial cells and by osteoblasts, osteocytes, osteoclasts (at protein level). Mutant mice are responsive to the psychotropic effects of cannabinoid but not to the cannabinoid-induced immunomodulation. They also show accelerated age-related trabecular bone loss and cortical expansion. Belongs to the G-protein coupled receptor 1 family.