5HT2Areseptoreihin

5HT2A receptors are a subtype of serotonin (5-hydroxytryptamine, 5-HT) receptors that belong to the family of G‑protein coupled receptors. They are encoded by the HTR2A gene and are primarily coupled to Gq proteins, leading to activation of phospholipase C and downstream signaling pathways such as intracellular calcium mobilization and protein kinase C activation.

These receptors are widely distributed in the central nervous system. In the brain they are found in cortical regions, the thalamus, hippocampus, basal ganglia, and brainstem nuclei, as well as on a variety of neuronal and glial cells. Peripheral expression includes vascular smooth muscle, platelets, and gastrointestinal tissues, where they modulate vasoconstriction, platelet aggregation, and digestive motility.

Ligands for 5HT2A receptors comprise endogenous serotonin, synthetic hallucinogenic phenethylamines (e.g. LSD and mescaline), and various antipsychotic drugs (e.g. clozapine and risperidone) that act as antagonists. The receptor’s unique binding pocket allows high affinity interactions with tryptamine and indole compounds, which has been exploited in pharmacophore modeling.

Clinically, 5HT2A receptor activity is implicated in psychiatric conditions, notably schizophrenia and depression. Antagonism at these receptors is a key mechanism of several atypical antipsychotics, which improves positive symptoms while exerting fewer extrapyramidal side effects compared to first‑generation agents. Conversely, agonism of the receptor is associated with psychedelic sensory experiences, and a rapidly expanding field of research explores therapeutic potential for conditions such as treatment‑resistant depression, anxiety, and obsessive‑compulsive disorder using controlled serotonergic psychedelics.

In addition, 5HT2A receptors modulate neuroplasticity, influencing dendritic spine density and gene expression related to synaptic function. Dysregulation of receptor signaling has been linked to neurodegenerative disorders, although the precise role remains under investigation. Ongoing studies aim to delineate receptor subpopulations, isoforms, and allosteric modulators to develop more selective therapeutics for both central and peripheral indications.