Article date: 1990/5/1
PubMed ID: 2161544
Journal name: Pharmacology, biochemistry, and behavior (ISSN: 0091-3057)
Certain drugs generally regarded as GABA agonists, such as valproate and combinations of muscimol and baclofen, have been reported to produce apparent anxiolytic effects in various animal behavioral tests. The present paper reports two experiments on the effects of these agents on conditioned suppression in rats. In the first study, muscimol (0, 1.25 micrograms/kg or 1 mg/kg), baclofen (0, 1 mg/kg) and combinations of these treatments failed to alleviate conditioned suppression. Experiment Two showed that valproate (200 mg/kg) did attenuate conditioned suppression, and that its effects were antagonised by picrotoxin (1.5 mg/kg), but not by bicuculline (1.5 mg/kg), Ro 15-1788 (10 mg/kg) or by delta-amino-n-valeric acid (10 mg/kg). The findings are discussed in the context of the proposed GABA/benzodiazepine receptor complex, with the conclusion that there is little evidence for a mediating role of GABAa or GABAb receptors in such drug actions, and that the site of valproate action is probably the chloride ion channel associated with the receptor complex.
Author List: Shephard R A, Toal L, Leslie J C
Publication Types: Journal Article
Substances mentioned in the article: GABA Antagonists; GABA-A Receptor Antagonists; Receptors, GABA-A; Muscimol; Valproic Acid; Baclofen;
Mesh terms: Animals; Baclofen/pharmacology; Conditioning, Classical/drug effects; Drug Interactions; GABA Antagonists; GABA-A Receptor Antagonists; Male; Muscimol/pharmacology; Rats; Rats, Inbred Strains; Receptors, GABA-A/physiology; Valproic Acid/pharmacology;