Article date: 1992/8/25
PubMed ID: 1330605
Journal name: European journal of pharmacology (ISSN: 0014-2999)
A microdialysis probe implanted into the substantia nigra was used to infuse gamma-aminobutyric acid-ergic (GABAergic) compounds onto cell bodies/dendrites of dopaminergic neurons, while a second microdialysis probe was used to record the extracellular concentrations of dopamine and 3,4-dihydroxy-phenylacetic acid (DOPAC) in the ipsilateral striatum. The GABAA receptor agonist muscimol (10 mumol/l) increased the release of dopamine in the ipsilateral striatum to 120% of the control values. The GABAB receptor agonist, (Z)-3[(aminoiminomethyl)-thiol]-prop-2- enoic acid (500 mumol/l), was without effect. Infusion of the GABAA receptor antagonists, bicuculline (50 mumol/l) and picrotoxin (50 mumol/l), stimulated the release of dopamine in the ipsilateral striatum to 160 and 130% of the controls, respectively. The GABAB receptor agonist, baclofen (10 and 50 mumol/l), strongly inhibited the release of striatal dopamine, whereas infusion of the GABAB receptor antagonist, 2-hydroxy-saclofen (100 mumol/l), was without effect. The results indicate that, in the substantia nigra, GABAA as well as GABAB receptors participate in controlling the activity of dopaminergic neurons.
Author List: Santiago M, Westerink B H
Publication Types: Journal Article; Research Support, Non-U.S. Gov't
Substances mentioned in the article: Acrylates; Receptors, GABA-A; 3,4-Dihydroxyphenylacetic Acid; Picrotoxin; Muscimol; 3-((aminoiminomethyl)thio)-2-propenoic acid; Baclofen; Dopamine; 2-hydroxysaclofen; Bicuculline;
Mesh terms: 3,4-Dihydroxyphenylacetic Acid/metabolism; Acrylates/pharmacology; Animals; Baclofen/analogs & derivatives; Bicuculline/pharmacology; Corpus Striatum/metabolism; Dendrites/metabolism; Dopamine/metabolism; Male; Muscimol/pharmacology; Neurons/metabolism; Picrotoxin/pharmacology; Rats; Rats, Wistar; Receptors, GABA-A/metabolism; Substantia Nigra/drug effects;