5-HT2A receptor

Class

Serotonergic psychedelic

The 5-HT2A receptor is a subtype of serotonin receptor belonging to the G protein-coupled receptor (GPCR) family. It is densely expressed on cortical pyramidal neurons, particularly in prefrontal and other association cortices, and also occurs on platelets and vascular smooth muscle outside the brain. Because serotonin signaling through this receptor shapes cortical excitability, mood regulation, and perception, both activating (agonist) and blocking (antagonist) strategies have therapeutic rationale, depending on the clinical goal. Agonists at this receptor produce pronounced alterations in perception and cognition and are being explored for their capacity to promote transient network reorganization relevant to depression, post-traumatic stress, and certain substance use disorders. Antagonists, by contrast, dampen 5-HT2A signaling and are used where excess activity contributes to hallucinations or agitation, such as in psychosis associated with neurodegenerative disease, or where peripheral 5-HT2A activity contributes to platelet aggregation and vasoconstriction in vascular disease. The same receptor is therefore a target for opposite pharmacological approaches, chosen according to whether the therapeutic aim is to engage central serotonergic plasticity or to suppress excessive receptor signaling in the brain or periphery.