Modulation of acetylcholine release from rat striatal slices by the GABA/benzodiazepine receptor complex.
GABA, THIP and muscimol enhance spontaneous and inhibit electrically induced release of tritium labelled compounds from rat striatal slices which have been pre-labelled with 3H-choline. Baclofen is inactive in this model. Muscimol can inhibit electrically induced release of tritiated material by approximately 75% with half maximal effects at 2 microM. The response to muscimol can be blocked by the GABA antagonists bicuculline methobromide, picrotoxin, anisatin, R 5135 and CPTBO (cyclopentylbicyclophosphate). Drugs which act on the benzodiazepine receptor (BR) require the presence of muscimol to be effective and they modulate the effects of muscimol in a bidirectional manner. Thus BR agonists enhance and inverse BR agonists attenuate the inhibitory effects of muscimol on electrically induced release. Ro15-1788, a BR antagonist, does not modulate the inhibitory effects of muscimol but antagonizes the actions of clonazepam, a BR agonist, and of DMCM, an inverse BR agonist. These results demonstrate that a GABA/benzodiazepine receptor complex can modulate acetylcholine release from rat striatal slices in vitro.
Supavilai
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P
Karobath
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M
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001418:Baclofen / Q000494:pharmacology; D001570:Benzodiazepinones / Q000494:pharmacology; D002998:Clonazepam / Q000494:pharmacology; D003342:Corpus Striatum / Q000378:metabolism*; D004558:Electric Stimulation; D005442:Flumazenil; D006220:Haloperidol / Q000494:pharmacology; D066298:In Vitro Techniques; D007555:Isoxazoles / Q000494:pharmacology; D009118:Muscimol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D001570:Benzodiazepinones; D007555:Isoxazoles; D011963:Receptors, GABA-A; D009118:Muscimol; D005442:Flumazenil; D005680:gamma-Aminobutyric Acid; D002998:Clonazepam; D001285:Atropine; D001418:Baclofen; D006220:Haloperidol; C015542:gaboxadol; D000109:Acetylcholine