Recombinant Human HTR3A

Background

HTR3A is a subunit of the 5-HT3 receptor, a ligand-gated ion channel receptor that differs from the G protein-coupled serotonin receptors (5-HT1, 2, etc.). Found primarily in the central nervous system (CNS) and peripheral nervous system (PNS), HTR3A mediates fast excitatory neurotransmission in response to serotonin (5-HT). The receptor's activation allows for the influx of sodium (Na+) and calcium (Ca2+) ions across the neuronal membrane, leading to neuronal depolarization. HTR3A is crucial in regulating physiological processes such as nausea and vomiting, gastrointestinal motility, anxiety, and pain perception. It is highly expressed in the area postrema, a brain region involved in emetic responses. Consequently, 5-HT3 receptor antagonists like ondansetron are used clinically to prevent chemotherapy-induced nausea and vomiting (CINV). In the enteric nervous system, HTR3A modulates peristalsis and visceral pain, making it relevant for irritable bowel syndrome (IBS) treatment. Dysregulation of HTR3A function has also been implicated in neuropsychiatric disorders, including anxiety, depression, and schizophrenia. Genetic polymorphisms of HTR3A have been associated with heightened anxiety sensitivity and increased risk of mood disorders, indicating its therapeutic importance in both gastrointestinal and neurological contexts.