5-HT receptors, 5-hydroxytryptamine receptors, or serotonin receptors, are a group of G protein-coupled receptor and ligand-gated ion channels found in the central and peripheral nervous systems. They mediate both excitatory and inhibitory neurotransmission. The serotonin receptors are activated by the neurotransmitter serotonin, which acts as their natural ligand.
The 5-HT2A receptor is a subtype of the 5-HT2 receptor that belongs to the serotonin receptor family and is a G protein-coupled receptor (GPCR). The 5-HT2A receptor is a cell surface receptor, but has several intracellular locations. 5-HT is short for 5-hydroxy-tryptamine or serotonin. This is the main excitatory receptor subtype among the GPCRs for serotonin, although 5-HT2A may also have an inhibitory effect on certain areas such as the visual cortex and the orbitofrontal cortex. This receptor was first noted for its importance as a target of serotonergic psychedelic drugs such as LSD and psilocybin mushrooms. Later it came back to prominence because it was also found to be mediating, at least partly, the action of many antipsychotic drugs, especially the atypical ones.
A serotonin receptor agonist is an agonist of one or more serotonin receptors. They activate serotonin receptors in a manner similar to that of serotonin, a neurotransmitter and hormone and the endogenous ligand of the serotonin receptors.
5-Hydroxytryptamine receptor 2B (5-HT2B) also known as serotonin receptor 2B is a protein that in humans is encoded by the HTR2B gene. 5-HT2B is a member of the 5-HT2 receptor family that binds the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT).
5-Hydroxytryptamine (serotonin) receptor 5A, also known as HTR5A, is a protein that in humans is encoded by the HTR5A gene. Agonists and antagonists for 5-HT receptors, as well as serotonin uptake inhibitors, present promnesic (memory-promoting) and/or anti-amnesic effects under different conditions, and 5-HT receptors are also associated with neural changes.
The 5HT6 receptor is a subtype of 5HT receptor that binds the endogenous neurotransmitter serotonin (5-hydroxytryptamine, 5HT). It is a G protein-coupled receptor (GPCR) that is coupled to Gs and mediates excitatory neurotransmission. HTR6 denotes the human gene encoding for the receptor.
The 5-HT7 receptor is a member of the GPCR superfamily of cell surface receptors and is activated by the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) The 5-HT7 receptor is coupled to Gs (stimulates the production of the intracellular signaling molecule cAMP) and is expressed in a variety of human tissues, particularly in the brain, the gastrointestinal tract, and in various blood vessels. This receptor has been a drug development target for the treatment of several clinical disorders. The 5-HT7 receptor is encoded by the HTR7 gene, which in humans is transcribed into 3 different splice variants.
WAY-100635 is a piperazine drug and research chemical widely used in scientific studies. It was originally believed to act as a selective 5-HT1A receptor antagonist, but subsequent research showed that it also acts as potent full agonist at the D4 receptor. It is sometimes referred to as a silent antagonist at the former receptor. It is closely related to WAY-100135.
AS-19 is a substance which acts as a potent agonist at the 5-HT7 receptor, with an IC50 of 0.83nM. It reverses the amnesia induced by drugs such as scopolamine and dizocilpine and improves long-term memory acquisition, but inhibits short-term memory formation.
SB-269970 is a drug and research chemical developed by GlaxoSmithKline used in scientific studies. It is believed to act as a selective 5-HT7 receptor antagonist (EC50 = 1.25 nM) (or possibly inverse agonist). A subsequent study in guinea pig at a concentration of 10 μM showed that it also blocks the α2-adrenergic receptor. The large difference in test concentrations however confirms the selectivity of SB-269970 for the 5-HT7 receptor.
S-15535 is a phenylpiperazine drug which is a potent and highly selective 5-HT1A receptor ligand that acts as an agonist and antagonist at the presynaptic and postsynaptic 5-HT1A receptors, respectively. It has anxiolytic properties.
GR-127935 is a drug which acts as a selective antagonist at the serotonin receptors 5-HT1B and 5-HT1D. It has little effect when given by itself but blocks the antiaggressive effect of 5-HT1B agonists, and alters release of serotonin in the brain, as well as reducing drug-seeking behaviour in cocaine addicted rats.
Roxindole (EMD-49,980) is a dopaminergic and serotonergic drug which was originally developed by Merck KGaA for the treatment of schizophrenia. In clinical trials its antipsychotic efficacy was only modest but it was unexpectedly found to produce potent and rapid antidepressant and anxiolytic effects. As a result, roxindole was further researched for the treatment of depression instead. It has also been investigated as a therapy for Parkinson's disease and prolactinoma.
RH-34 is a compound which acts as a potent and selective partial agonist for the 5-HT2A serotonin receptor subtype. It was derived by structural modification of the selective 5-HT2A antagonist ketanserin, with the 4-(p-fluorobenzoyl)piperidine moiety replaced by the N-(2-methoxybenzyl) pharmacophore found in such potent 5-HT2A agonists as NBOMe-2C-B and NBOMe-2C-I. This alteration was found to retain 5-HT2A affinity and selectivity, but reversed activity from an antagonist to a moderate efficacy partial agonist.
LP-12 is a drug which acts as a potent agonist at the 5HT7 serotonin receptor, with very high selectivity over other tested receptor subtypes such as the serotonin 5-HT1A and 5-HT2A, and the dopamine D2 receptor. It has been used to research the involvement of the 5-HT7 receptor in as yet poorly understood processes such as allodynia and hyperalgesia.
LP-44 is a drug which acts as a potent and selective agonist at the 5HT7 serotonin receptor. While LP-44 is less selective than the related compound LP-12, it has been more widely used in research and has been used to show the complex role of 5-HT7 receptors in several aspects of brain function, including regulation of the sleep-wake cycle and roles in stress, learning and memory.
E-55888 is a drug developed by Esteve, which acts as a potent and selective full agonist at the 5HT7 serotonin receptor, and is used for investigating the role of 5-HT7 receptors in the perception of pain. When administered by itself, E-55888 is anti-hyperalgesic but not analgesic, but when administered alongside morphine, E-55888 was found to significantly increase the analgesic effects.
LP-211 is a drug which acts as a potent and selective agonist at the 5HT7 serotonin receptor, with better brain penetration than older 5-HT7 agonists in the same series, and similar effects in animals.
SB-206553 is a drug which acts as a mixed antagonist for the 5-HT2B and 5-HT2C serotonin receptors. It has anxiolytic properties in animal studies and interacts with a range of other drugs. It has also been shown to act as a positive allosteric modulator of α7 nicotinic acetylcholine receptors. Modified derivatives of SB-206553 have been used to probe the structure of the 5-HT2B receptor.
5-HT2C receptor agonists are a class of drugs that activate 5-HT2C receptors. They have been investigated for the treatment of a number of conditions including obesity, psychiatric disorders, sexual dysfunction and urinary incontinence.
