Low ethanol concentrations selectively augment the tonic inhibition mediated by delta subunit-containing GABAA receptors in hippocampal neurons

J Neurosci. 2004 Sep 22;24(38):8379-82. doi: 10.1523/JNEUROSCI.2040-04.2004.

Abstract

In central neurons, a tonic conductance is activated by ambient levels of the inhibitory transmitter GABA. Here, we show that in dentate gyrus granule cells, where tonic inhibition is mediated by delta subunit-containing GABA(A) receptors, this conductance is augmented by low concentrations (30 mM) of ethanol. In contrast, the tonic inhibition mediated by alpha5 subunit-containing receptors of CA1 pyramidal cells is not affected. The effect of ethanol on tonic inhibition specifically reduces the excitability of the dentate gyrus and identifies the delta subunit-dependent tonic inhibition as a likely site of ethanol action in the brain.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Dentate Gyrus / cytology
  • Dentate Gyrus / drug effects
  • Dentate Gyrus / metabolism
  • Dose-Response Relationship, Drug
  • Ethanol / pharmacology*
  • Excitatory Postsynaptic Potentials / drug effects
  • Hippocampus / cytology
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • In Vitro Techniques
  • Mice
  • Mice, Inbred C57BL
  • Neural Inhibition / drug effects*
  • Neural Inhibition / physiology
  • Neurons / drug effects
  • Neurons / metabolism*
  • Patch-Clamp Techniques
  • Protein Subunits / drug effects
  • Protein Subunits / metabolism
  • Pyramidal Cells / drug effects
  • Pyramidal Cells / metabolism
  • Receptors, GABA-A / drug effects
  • Receptors, GABA-A / metabolism*

Substances

  • Protein Subunits
  • Receptors, GABA-A
  • Ethanol