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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
5
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pubmed:dateCreated |
1992-6-5
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pubmed:abstractText |
Intracellular recordings were made from presumed dopamine-containing neurons in slices cut from the midbrain of the rat. Focal electrical stimulation produced a hyperpolarizing synaptic potential that was reduced by 75-95% by the GABAB-receptor antagonist 2-hydroxysaclofen (300 microM). 5-HT (3-100 microM) reduced the amplitude of the GABAB synaptic potential by 20-74%, with a 50% reduction at 10 microM, but did not reduce the amplitude of synaptic potentials mediated by GABAA receptors. 5-HT acted presynaptically because hyperpolarizations produced by exogenously administered GABA (1 mM) in picrotoxin (100 microM) were not affected by 5-HT (30 microM). (+/-)-Cyanopindolol (100 nM), a 5-HT1B antagonist, blocked the effect of 5-HT (10 microM); spiperone (1 microM), which is an antagonist at 5-HT1A and 5-HT2 receptors, had no effect. The amplitude of the GABAB synaptic potential was reduced by the 5-HT1B receptor agonists 1-[3-(trifluoromethyl)-phenyl]-piperazine (300 nM) and 7-trifluoromethyl-4-(4-methyl-1-piperazinyl)-pyrrolo[1,2-a]quinoxaline (1 microM), but not by the 5-HT1A agonist N,N-dipropyl-5-carboxamidotryptamine (1 microM) or the 5-HT2 agonist (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-amino-propane (10 microM). We conclude that 5-HT activates presynaptic 5-HT1B receptors that inhibit the release of GABA onto GABAB but not GABAA receptors.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
May
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pubmed:issn |
0270-6474
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
12
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
2000-6
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:1578282-Animals,
pubmed-meshheading:1578282-Dopamine,
pubmed-meshheading:1578282-Electrophysiology,
pubmed-meshheading:1578282-Male,
pubmed-meshheading:1578282-Neurons,
pubmed-meshheading:1578282-Rats,
pubmed-meshheading:1578282-Rats, Inbred Strains,
pubmed-meshheading:1578282-Receptors, Serotonin,
pubmed-meshheading:1578282-Serotonin,
pubmed-meshheading:1578282-Synapses,
pubmed-meshheading:1578282-gamma-Aminobutyric Acid
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pubmed:year |
1992
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pubmed:articleTitle |
5-hydroxytryptamine1B receptors block the GABAB synaptic potential in rat dopamine neurons.
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pubmed:affiliation |
Vollum Institute, Oregon Health Sciences University, Portland 97201.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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