This is one of the several different receptors for 5-hydroxytryptamine (serotonin), a biogenic hormone that functions as a neurotransmitter, a hormone, and a mitogen. The activity of this receptor is mediated by G proteins that stimulate adenylate cyclase. It has a high affinity for tricyclic psychotropic drugs (By similarity). Controls pyramidal neurons migration during corticogenesis, through the regulation of CDK5 activity (By similarity). Is an activator of TOR signaling (PubMed:23027611). Interacts with MTOR, RPTOR and NF1 (PubMed:23027611). Interacts with CDK5 (By similarity). Expressed in several human brain regions, most prominently in the caudate nucleus. Belongs to the G-protein coupled receptor 1 family.