Effects of benzodiazepines and pentobarbitone on the gaba-ergic recurrent inhibition of hippocampal neurons.
The actions of benzodiazepines and pentobarbitone on GABA-mediated recurrent inhibition of hippocampal pyramidal neurons were investigated in the immobilized unanaesthetized cat. Extracellular action potentials of single neurons were recorded in regions CA1 or CA2 with 4 M NaCl-containing glass micropipettes. Bicuculline (0.1 mg/kg i.v.) reduced the period of inhibition induced by stimulation of the fimbria and the septum, but fludiazepam and diazepam (0.3--1.0 mg/kg i.v.) and pentobarbitone (15--30 mg/kg i.v.) prolonged the inhibition. The prolongation produced by these compounds was antagonized by the administration of bicuculline (0.3 mg/kg i.v.). The results suggest that these two classes of compounds potentiate GABA-mediated recurrent inhibition in hippocampal neurons in a similar way.
D000200:Action Potentials / Q000187:drug effects; D000613:Aminobutyrates / Q000494:pharmacology*; D000818:Animals; D001569:Benzodiazepines / Q000494:pharmacology*; D001640:Bicuculline / Q000494:pharmacology; D002415:Cats; D003975:Diazepam / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004357:Drug Synergism; D005260:Female; D006624:Hippocampus / Q000187:drug effects; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects; D010424:Pentobarbital / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D000613:Aminobutyrates; D001569:Benzodiazepines; D005680:gamma-Aminobutyric Acid; D010424:Pentobarbital; D003975:Diazepam; D001640:Bicuculline