Serotonin 5-hydroxytryptamine 6 receptor (5-HT6 receptor)

The serotonin 5-hydroxytryptamine 6 receptor (5‑HT₆ receptor) is a member of the G protein-coupled receptor family predominantly expressed in the central nervous system, especially within brain regions associated with cognition such as the cortex and hippocampus. It binds serotonin as its endogenous ligand. Functionally, this excitatory GPCR modulates multiple neurotransmitter systems—blocking it enhances glutamatergic/cholinergic transmission while stimulating it increases GABAergic signaling. The unique distribution pattern makes it an attractive target for neuropsychiatric drug development. Therapeutically, both antagonists and agonists have shown promise in preclinical models to improve cognitive function; however, large clinical trials targeting Alzheimer’s disease with selective antagonists like idalopirdine or intepirdine did not demonstrate significant benefit over placebo. Other indications under investigation include depression, anxiety disorders, obsessive-compulsive disorder, schizophrenia adjunct therapy, and obesity. Several highly selective ligands exist—some currently being tested clinically—including idalopirdine (antagonist), masupirdine/SUVN502 (antagonist), HEC30654 (antagonist), WAY181187/WAY208466/EMDT/E6837/E6801/EMD386088 among others as agonist or partial agonist probes. Structurally resolved by cryo-electron microscopy at high resolution,[1] key residues essential for ligand binding have been identified that inform ongoing drug design efforts aimed at improving selectivity/safety profiles.[1] No major spelling errors or conceptual issues are present regarding this target name—it is well-established scientifically as a therapeutic target within neuroscience research.[1][2][3]

Other names

5-HT6 receptor5-hydroxytryptamine receptor 6HTR6

Antagonists block the excitatory action of serotonin at the 5‑HT₆ receptor. This blockade increases glutamatergic and cholinergic neurotransmission in brain regions involved in cognition and memory. Antagonism also facilitates dopamine and norepinephrine release in the frontal cortex. Agonists enhance GABAergic signaling and may have antidepressant or anxiolytic effects. Both antagonism and agonism can produce procognitive effects through different mechanisms.[1][2][3][6][7]