Serotonin 5-hydroxytryptamine receptor 2A and 2B (5-HT2A/2B receptor)

The serotonin 5-HT2A and 5-HT2B receptors are closely related members of the serotonin receptor family, both belonging to the class A G protein-coupled receptor family. The 5-HT2A receptor is abundantly expressed in the central nervous system and is implicated in mediating the effects of hallucinogens, as well as contributing to processes such as cognition, mood regulation, and perception[1][4][5]. The 5-HT2B receptor is found primarily in peripheral tissues, including the cardiovascular system, and is responsible for mediating vascular tone and contributing to drug-induced cardiac valvulopathy and fibrotic disorders[2]. Both receptors play roles in psychiatric disease, cardiovascular physiology, and the mechanism of action of diverse pharmacological agents ranging from antipsychotics to hallucinogens. Their activity is mediated by G protein-coupled activation of downstream signaling cascades, most notably via Gq/11, resulting in increased intracellular calcium and subsequent effects on cell physiology[1][2][5]. Cardiac safety concerns have largely restricted therapeutic targeting of the 2B subtype, whereas the 2A subtype remains a crucial target of antipsychotics and psychedelic drugs.

Other names

5-HT2A receptor5-HT2B receptor5-HT2A/2BHTR2A (gene symbol, 2A)HTR2B (gene symbol, 2B)Serotonin receptor 2ASerotonin receptor 2B5-hydroxytryptamine receptor 2A5-hydroxytryptamine receptor 2B

Agonists activate the receptor, triggering G protein (mainly Gq/11) signaling, increasing phospholipase C activity, and intracellular calcium release[1][2][5]. Antagonists block serotonin or exogenous ligand binding, reducing receptor-mediated signaling[4][5]. Partial agonists induce submaximal activation. Inverse agonists decrease basal receptor activity. Biased agonists preferentially activate certain intracellular pathways (e.g., arrestin-dependent vs G protein-dependent signaling)[1][2].