Specific antagonism of GABA-mediated postsynaptic inhibition in cultured mammalian spinal cord neurons: a common mode of convulsant action.
Mammalian spinal neurons grown in tissue culture were used to study the effects of the four convulsants-penicillin, pentylenetetrazol, picrotoxin, and bicuculline-on these neurons' responses to amino acids. Bath application of all four convulsants produced paroxysmal depolarizing events in the neurons; iontophoresis of the four convulsants selectively depressed responses produced by iontophoresis of the putative inhibitory transmitter GABA, and effected this depression without altering either inhibitory responses to beta-alanine or glycine, or excitation mediated by glutamate. These results support the hypothesis that the convulsant activity of these agents comes in part from selective antagonism of GABA-mediated postsynaptic inhibition.
D000596:Amino Acids / Q000494:pharmacology; D000613:Aminobutyrates / Q000502:physiology*; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D003292:Convulsants / Q000008:administration & dosage / Q000494:pharmacology*; D046508:Culture Techniques; D007478:Iontophoresis; D051379:Mice; D009433:Neural Inhibition / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects; D010406:Penicillins / Q000494:pharmacology; D010433:Pentylenetetrazole / Q000494:pharmacology; D010852:Picrotoxin / Q000494:pharmacology; D013116:Spinal Cord / Q000166:cytology / Q000187:drug effects*; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D000596:Amino Acids; D000613:Aminobutyrates; D001640:Bicuculline; D003292:Convulsants; D010406:Penicillins; D010433:Pentylenetetrazole; D010852:Picrotoxin; D005680:gamma-Aminobutyric Acid