Article date: 1985/12/1
PubMed ID: 2869447
Journal name: Neuroscience (ISSN: 0306-4522)
In free-moving male rats, when the hippocampal theta rhythm is artificially driven by stimulation in the septum at frequencies between 5 and 10 Hz, the function relating frequency to the threshold current required to drive the theta rhythm has a minimum at 7.7 Hz. This minimum is eliminated by anxiolytic drugs. Dose-response curves for this effect are reported for chlordiazepoxide, diazepam and meprobamate. The effect of meprobamate was reversed by two gamma-aminobutyrateA antagonists, picrotoxin and bicuculline, which have previously been shown to be without effects of their own. The gamma-aminobutyrateB agonist, baclofen, also without effect on its own, blocked the elimination of the 7.7-Hz minimum caused by the gamma-aminobutyrateA agonist, muscimol. The beta-carboline, ethyl-beta-carboline-3-carboxylate, had mixed agonist/antagonist properties, blocking the effects of chlordiazepoxide, diazepam and muscimol (though not sodium amylobarbitone) but itself acting like a benzodiazepine. Coupled with earlier data, these findings support a role for gamma-aminobutyrate receptors in mediating the effects of anxiolytic drugs.
Author List: Quintero S, Mellanby J, Thompson M R, Nordeen H, Nutt D, McNaughton N, Gray J A
Publication Types: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't
Substances mentioned in the article: Anti-Anxiety Agents; Carbolines; Receptors, GABA-A; Chlordiazepoxide; beta-carboline-3-carboxylic acid ethyl ester; Meprobamate; Baclofen; Diazepam;
Mesh terms: Animals; Anti-Anxiety Agents/pharmacology; Baclofen/pharmacology; Carbolines/pharmacology; Chlordiazepoxide/pharmacology; Diazepam/pharmacology; Hippocampus/drug effects; Male; Meprobamate/pharmacology; Neural Pathways/drug effects; Rats; Rats, Inbred Strains; Receptors, GABA-A/drug effects; Septum Pellucidum/drug effects; Theta Rhythm;