The benzodiazepine triazolam: direct and GABA depressant effects on cultured mouse spinal cord neurons.
Whole-cell and outside-out patch clamp recordings were used to study the effects of the benzodiazepine triazolam at the membrane of mouse spinal cord neurons in cell culture. At 1 microM, triazolam reversibly increased the membrane conductance of about half of the spinal cord cells tested, the average increase being 24 +/- 4%. Depolarizations evoked by successive applications of gamma-aminobutyric acid (GABA) to the spinal cord cell membrane were attenuated by 1 microM triazolam in about half of the neurons tested. At 1-10 microM, triazolam also reduced the charge transfer triggered by GABA in outside-out patches of spinal cord cell membrane. In contrast, 10 microM diazepam potentiated charge transfer by the GABA receptor complexes. Triazolam apparently acts as an inverse agonist at benzodiazepine receptors expressed on spinal cord cells in culture. The well known anxiolytic effects of this drug are presumably mediated by benzodiazepine receptor types not assayed in the present experiments.
D000818:Animals; D002478:Cells, Cultured; D005071:Evoked Potentials / Q000187:drug effects; D018756:GABA Antagonists; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000166:cytology / Q000187:drug effects*; D013116:Spinal Cord / Q000502:physiology; D014229:Triazolam / Q000494:pharmacology*
D018756:GABA Antagonists; D014229:Triazolam