5-HT1B receptor

5-hydroxytryptamine receptor 1B also known as the 5-HT_1B receptor is a protein that in humans is encoded by the HTR1B gene. The 5-HT_1B receptor is a 5-HT receptor subtype.

Tissue distribution and function

5-HT_1B receptors are widely distributed throughout the CNS with the highest concentrations found in the frontal cortex, basal ganglia, striatum, and the hippocampus. The function of the 5-HT_1B receptor differs depending upon its location. In the frontal cortex, it is believed to act as a postsynaptic receptor inhibiting the release of dopamine. In the basal ganglia and the striatum, evidence suggests 5-HT signaling acts on an autoreceptor, inhibiting the release of serotonin and decreasing glutamatergic transmission by reducing miniature excitatory postsynaptic potential (mEPSP) frequency, respectively. In the hippocampus, a recent study has demonstrated that activation of postsynaptic 5-HT_1B heteroreceptors produces a facilitation in excitatory synaptic transmission which is altered in depression. When the expression of 5-HT_1B in human cortex was traced throughout life, significant changes during adolescence were observed, in a way that is strongly correlated with the expression of 5-HT_1E.

Outside the brain, 5-HT_1B receptor activation also has vascular effects, such as pulmonary vasoconstriction. Furthermore, blocking 5-HT_1B receptor signalling increases the number of osteoblasts, bone mass, and the bone formation rate.

Knockout mice lacking the 5-HT_1B gene have shown an increase in aggression and a higher preference for alcohol. Under basal conditions, knockout mice present with a "normal" phenotype and exhibit a sucrose preference (lack of sucrose preference is considered a measure of anhedonia). However, after undergoing chronic unpredictable stress treatment to induce a "depression-like" phenotype these animals do not benefit from administration of selective serotonin reuptake inhibitor (SSRIs).

Ligands

Agonists

• ergotamine (vasoconstrictor in migraine)
• Oxymetazoline
• sumatriptan (vasoconstrictor in migraine)
• zolmitriptan
• 5-Carboxamidotryptamine
• CGS-12066A
• CP-93,129 (peripherally acting)
• CP-94,253
• CP-122,288 (mixed 5-HT_1B/1D agonist)
• CP-135,807 (mixed 5-HT_1B/1D agonist)
• RU-24969 (mixed 5-HT_1A/1B agonist)

Partial agonists

• Vortioxetine (antidepressant)
• Ziprasidone (antipsychotic)
• Asenapine (antipsychotic)

Antagonists and inverse agonists

• methiothepin (antipsychotic)
• yohimbine (aphrodisiac)
• metergoline
• Aripiprazole
• isamoltane
• AR-A000002
• SB-216,641
• SB-224,289 (inverse agonist)
• SB-236,057 (inverse agonist)

Genetics

In humans the protein is coded by the gene HTR1B.

A genetic variant in the promotor region, A-161T, has been examined with respect to personality traits and showed no major effect.

See also

• 5-HT₁ receptor
• 5-HT receptor

External links

This article incorporates text from the United States National Library of Medicine, which is in the public domain.