2575444

Serotonin microinfusion into the ventral tegmental area increases accumbens dopamine release.

Article date: 1989/12/1

PubMed ID: 2575444

Journal name: Brain research bulletin (ISSN: 0361-9230)

ABSTRACT

The effects of microinfusion of serotonin (5-HT) agents as well as glutamate and muscimol into the ventral tegmental area (VTA) on dopamine (DA) release in the ipsilateral nucleus accumbens (ACC) were investigated in freely moving rats, using a push-pull perfusion procedure. The baseline values for DA, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were approximately 0.24, 8.4, 2.1 and 2.7 pmol/15 min, respectively, in the push-pull perfusate of the ACC. When microinfused into the VTA, glutamate (0.74 microgram) significantly (p less than 0.05) increased the contents of DOPAC (110%) and HVA (90%) over baseline levels in the perfusate. On the other hand, 0.5 microgram muscimol (a gamma-amino-n-butyric acid, GABA, agonist) significantly, (p less than 0.05) decreased both DA (40%) and DOPAC (20%) levels relative to baseline values. Administration of 2 micrograms 5-HT into the VTA caused a significant (p less than 0.05) elevation in the perfusate levels of DOPAC (80%) and HVA (70%) over baseline values. A similar effect was obtained with a nonselective 5-HT1 agonist but not with a selective 5-HT1A agonist. The results suggest that 5-HT innervations in the VTA may have an excitatory action possibly via 5-HT1B rather than 5-HT1A receptors on the mesolimbic DA system projecting to the ACC and that this DA system may also be regulated by glutamatergic and GABAergic (via GABAA receptors) inputs.

This document is available from: http://directlinks.cc/files/muscimol/2575444.pdf

Author List: Guan X M, McBride W J

Publication Types: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.

Substances mentioned in the article: Glutamates; 3,4-Dihydroxyphenylacetic Acid; Muscimol; Serotonin; Glutamic Acid; Dopamine;

Mesh terms: 3,4-Dihydroxyphenylacetic Acid/metabolism; Animals; Dopamine/metabolism; Functional Laterality; Glutamates/pharmacology; Glutamic Acid; Male; Muscimol/pharmacology; Nucleus Accumbens/metabolism; Rats; Rats, Inbred Strains; Septal Nuclei/metabolism; Serotonin/pharmacology; Tegmentum Mesencephali/drug effects;

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