Alcohol modulation of single GABA(A) receptor-channel kinetics.
Alcohol modulation of single-channel kinetics of GABA(A) receptor currents was studied with rat dorsal root ganglion neurons using the excised outside-out patch clamp technique. GABA (1 microM) alone or GABA (1 microM) plus ethanol (30-300 mM) or n-Octanol (30-300 microM) were applied by pressure ejection to evoke single-channel currents. The main single-channel conductance was not changed by either ethanol or n-Octanol at 25 pS. Both alcohols exerted the same effects on the single-channel kinetics, although n-Octanol was more potent than ethanol. The frequency of openings, the mean open time, the percentage of open time, the frequency of bursts, and the mean burst duration were all increased, but the mean closed time was decreased. These changes in channel kinetics account for the increase in whole-cell current amplitude caused by ethanol and n-Octanol.
Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Medical School, Chicago, IL 60611, USA.
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Tatebayashi
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Motomura
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Narahashi
D020003:1-Octanol / Q000494:pharmacology*; D000818:Animals; D000431:Ethanol / Q000494:pharmacology*; D018757:GABA Modulators / Q000494:pharmacology*; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects*; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D051381:Rats; D011963:Receptors, GABA-A / Q000187:drug effects*
D018757:GABA Modulators; D011963:Receptors, GABA-A; D000431:Ethanol; D020003:1-Octanol