G-protein coupled receptor for 5-hydroxytryptamine (serotonin), a biogenic hormone that functions as a neurotransmitter, a hormone and a mitogen. Also has a high affinity for tricyclic psychotropic drugs. Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors. HTR6 is coupled to G(s) G alpha proteins and mediates activation of adenylate cyclase activity. Controls pyramidal neurons migration during corticogenesis, through the regulation of CDK5 activity. Is an activator of mTOR signaling 