RGD Reference Report - Selective heterologous regulation of 5-HT1A receptor-stimulated 35S GTPgammaS binding in the anterior cingulate cortex as a result of 5-HT2 receptor activation. - Rat Genome Database

RGD Reference Report - Selective heterologous regulation of 5-HT1A receptor-stimulated 35S GTPgammaS binding in the anterior cingulate cortex as a result of 5-HT2 receptor activation. - Rat Genome Database

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Selective heterologous regulation of 5-HT1A receptor-stimulated 35S GTPgammaS binding in the anterior cingulate cortex as a result of 5-HT2 receptor activation.
Authors:	Valdez, M Burke, TF Hensler, JG
Citation:	Valdez M, etal., Brain Res 2002 Dec 6;957(1):174-82.
RGD ID:	729373
Pubmed:	PMID:12443993 (View Abstract at PubMed)
Previous studies have shown that administration of the 5-HT(2) receptor agonist DOI to rats results in the heterologous desensitization of 5-HT(1A) receptor-mediated behavioral and neuroendocrine responses [Neuropsychopharmacology 19 (1998) 354; J. Neurosci. 21 (2001) 7919]. We hypothesized that the basis for these changes in 5-HT(1A) receptor function may involve changes in the capacity of the 5-HT(1A) receptor to activate G proteins. We examined the effect of chronic administration of DOI on the regulation of 5-HT(1A) receptor function at the level of receptor-G protein interaction using quantitative autoradiography of [(35)S]GTPgammaS binding stimulated by the 5-HT(1A) receptor agonist (+/-)8-OH-DPAT (1 microM). Repeated administration of DOI (1 mg/kg, s.c. once daily for 8 days) resulted in a marked down-regulation in 5-HT(2A) binding sites, as labeled by the antagonist radioligand [(3)H]ketanserin, throughout the cerebral cortex. Chronic DOI treatment also resulted in a significant and selective attenuation of 5-HT(1A) receptor-stimulated [(35)S]GTPgammaS binding in the anterior cingulate cortex (vehicle-treated: 74+/-7.7% above basal; DOI-treated: 43+/-4.6% above basal). Interestingly, 5-HT(1A) receptor-stimulated [(35)S]GTPgammaS binding was not altered in the dorsal or median raphe, or in the limbic structures and other cortical regions examined. The decrease in 5-HT(1A) receptor-stimulated [(35)S]GTPgammaS binding in anterior cingulate cortex was not due to a decrease in 5-HT(1A) receptor number, indicating that the capacity of the 5-HT(1A) receptor to activate G proteins is attenuated in this cortical area following repeated DOI treatment. The heterologous regulation of 5-HT(1A) receptor function by chronic 5-HT(2) receptor activation in the anterior cingulate cortex raises interesting questions as to how the regulatory interaction between these serotonin receptor subtypes influences cognition, memory and emotion.

Objects referenced in this article

Gene	Htr1a	5-hydroxytryptamine receptor 1A	Rattus norvegicus
Gene	Htr2a	5-hydroxytryptamine receptor 2A	Rattus norvegicus

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