Serotonin 1 and 2 receptors (5-HT1/2R)

The 5-HT1 and 5-HT2 receptors represent two distinct families of G protein-coupled receptors (GPCRs) that respond to the neurotransmitter serotonin (5-hydroxytryptamine). The 5-HT1 family, comprising subtypes 1A, 1B, 1D, 1E, and 1F, primarily couples to Gi/o proteins to inhibit adenylyl cyclase, thereby reducing intracellular cAMP levels (Source: IUPHAR/BPS Guide to Pharmacology). These receptors are widely distributed in the central nervous system and are involved in regulating mood, anxiety, and the release of other neurotransmitters. In contrast, the 5-HT2 family, including subtypes 2A, 2B, and 2C, couples to Gq/11 proteins to activate phospholipase C, leading to increased intracellular calcium and protein kinase C activation (Source: StatPearls, Serotonin). This family is crucial for modulating perception, appetite, and smooth muscle contraction. Clinically, these receptors are major therapeutic targets for a variety of conditions. 5-HT1B and 5-HT1D agonists, known as triptans, are standard treatments for acute migraine due to their vasoconstrictive effects on cranial blood vessels (Source: PubMed, PMID: 15505004). 5-HT2A receptor antagonism is a hallmark of atypical antipsychotics like clozapine and risperidone, which help manage schizophrenia symptoms with a lower risk of extrapyramidal side effects compared to older agents (Source: NIH, PubChem). Furthermore, 5-HT1A partial agonists like buspirone are utilized in treating generalized anxiety disorder. Safety considerations are paramount, as overstimulation can lead to life-threatening serotonin syndrome, and chronic activation of the 5-HT2B subtype has been linked to cardiac valvulopathy (Source: FDA, Drug Safety Communications).

Other names

5-HT1 receptors5-HT2 receptors5-Hydroxytryptamine 1/2 receptorsSerotonin 1/2 receptors

Drugs targeting these receptors act through various mechanisms: 5-HT1 agonists (e.g., triptans) cause vasoconstriction and inhibit neuropeptide release; 5-HT1A partial agonists (e.g., buspirone) modulate mood; 5-HT2A antagonists (e.g., atypical antipsychotics) reduce psychotic symptoms; and 5-HT2C agonists (e.g., lorcaserin) suppress appetite.