HTR2B (5-Hydroxytryptamine receptor 2B, serotonin receptor 2B) is a G-protein coupled receptor that binds serotonin as well as various ergot alkaloid derivatives and psychoactive substances. This receptor affects neural activity by regulating dopamine and serotonin release and uptake and by controlling extracellular levels of these neurotransmitters. HTR2B is involved in neuronal sensitization to tactile stimuli, behavioral regulation including impulsive behavior, and it may also play a role in the perception of pain. Mice lacking HTR2B have exhibited a schizophrenic-like phenotype and thus HTR2B is of interest in psychotic disorder neurobiology. It also has various cardiovascular roles; it is required for normal proliferation of embryonic cardiac myocytes and normal heart development and functions to protect cardiomyocytes against apoptosis. It is also necessary for normal osteoblast function and proliferation and for maintaining normal bone density. HTR2B agonists are of interest as possible treatments for migraines and chronic heart disease. In immunohistochemistry, HTR2B has highest cytoplasmic and membranous positivity in the cervix and endometrium. It is found in arcuate neurons in the brain, and it has positive staining in most other tissues. References: The Journal of Neuroscience. 28 (11): 2933–40, PMID: 18337424; Circulation Research. 104 (1): 1–3, PMID: 19118279; Mini Reviews in Medicinal Chemistry. 4 (3): 325–30, PMID: 15032678; Neuropsychopharmacology. 2015 Nov;40(12):2764-73, PMID: 25936642; J Exp Med. 2011 Jan 17;208(1):41-52,PMID: 21187319