Orphan receptor. Displays a significant level of constitutive activity. Its effect is mediated by G(s)-alpha protein that stimulate adenylate cyclase, resulting in an elevation of intracellular cAMP (By similarity). Detected in extracts of several brain regions including striatum, pons, cerebellum and cortex. Not detected in numerous peripheral tissue extracts, except in testis. In the brain, detected in cortical structures including the anterior cingulate area, posterior cingulate and the frontoparietal, somatosensory and piriform cortices. Prominent also in the olfactory tubercle, the islands of Calleja, ventromedial and posterior nuclei of the hypothalamus, the medial septal nucleus, nucleus of the diagonal band and the ventral tegmental area. Localized also to hippocampal structures, with signals strongest over the CA2 and CA3 regions of Ammon's horn and less so over the dentate gyrus. Expressed in the caudate putamen only in its most caudal portion, with a decreasing gradient of signal from the dorsal to ventral aspect. Strong expression associated with a single pontine structure, the inferior olivary nucleus. Belongs to the G-protein coupled receptor 1 family.