title: Septal driving of hippocampal theta rhythm: role of gamma-aminobutyrate-benzodiazepine receptor complex in mediating effects of anxiolytics.
abstract: 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.
authors.forename: S
authors.initials: S
authors.lastname: Quintero
authors.forename: J
authors.initials: J
authors.lastname: Mellanby
authors.forename: M R
authors.initials: MR
authors.lastname: Thompson
authors.forename: H
authors.initials: H
authors.lastname: Nordeen
authors.forename: D
authors.initials: D
authors.lastname: Nutt
authors.forename: N
authors.initials: N
authors.lastname: McNaughton
authors.forename: J A
authors.initials: JA
authors.lastname: Gray
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001418:Baclofen / Q000494:pharmacology; D002243:Carbolines / Q000494:pharmacology; D002707:Chlordiazepoxide / Q000494:pharmacology; D003975:Diazepam / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects*; D008297:Male; D008620:Meprobamate / Q000494:pharmacology; D009434:Neural Pathways / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects*; D012688:Septum Pellucidum / Q000187:drug effects*; D013826:Theta Rhythm
chemical_list: D014151:Anti-Anxiety Agents; D002243:Carbolines; D011963:Receptors, GABA-A; D002707:Chlordiazepoxide; C024915:beta-carboline-3-carboxylic acid ethyl ester; D008620:Meprobamate; D001418:Baclofen; D003975:Diazepam