Serotonin 5-hydroxytryptamine 3 Receptor (5-HT3)

The serotonin 5-hydroxytryptamine 3 receptor (5-HT3) is a ligand-gated ion channel that belongs to the Cys-loop superfamily of neurotransmitter receptors. Unlike other serotonin receptors, which are G-protein-coupled, the 5-HT3 receptor is unique in being an ionotropic receptor. Activation by serotonin leads to rapid opening of this cation-selective channel, allowing sodium (Na+), potassium (K+), and calcium (Ca2+) ions to flow into neurons, resulting in neuronal depolarization/excitation and neurotransmitter release. The receptor is involved in emesis, pain processing, reward pathways, cognition, anxiety control, and gastrointestinal function. Antagonists ("setrons" e.g., ondansetron) are widely used clinically to prevent chemotherapy-induced nausea/vomiting.

Other names

5-HT3 receptor

5-HT3 receptor antagonists block the receptor, reducing the effects of serotonin and preventing neuronal excitation.