Enhancement of GABAergic inhibition: a mechanism of action of benzodiazepines, phenobarbital, valproate and L-cycloserine in the cat spinal cord.
Unanaesthetized spinal cats were used to assess the effects of several central depressant drugs on GABA-mediated presynaptic inhibition. Benzodiazepines enhance GABAergic inhibition by interaction with specific receptors in the spinal cord. Phenobarbital facilitates GABAergic inhibition by a mechanism unrelated to that of benzodiazepines, perhaps by an effect on the Cl- ionophore within the GABA-benzodiazepine-barbiturate receptor complex. A similar mechanism or the inhibition of GABA re-uptake might be responsible for the facilitating effect of valproate on GABA transmission. By selectively inhibiting GABA transaminase, L-cycloserine presumably increases the amount of GABA available for release.
D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology*; D001569:Benzodiazepines; D002415:Cats; D003523:Cycloserine / Q000494:pharmacology*; D018756:GABA Antagonists; D007395:Interneurons / Q000187:drug effects / Q000502:physiology*; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D010634:Phenobarbital / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*; D014635:Valproic Acid / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology
D014151:Anti-Anxiety Agents; D018756:GABA Antagonists; D001569:Benzodiazepines; D005680:gamma-Aminobutyric Acid; D014635:Valproic Acid; D003523:Cycloserine; D010634:Phenobarbital