Long-lasting changes in GABA responsiveness in cultured neurons

Neurosci Lett. 2004 Jul 15;365(1):69-72. doi: 10.1016/j.neulet.2004.04.049.

Abstract

In neuronal cells, GABA evokes an increase in chloride conductance by activating GABA(A) and GABA(C) receptors. In mature neurons, this increase in conductance generally has a hyperpolarizing and inhibitory action. Using gramicidin-based perforated patch recordings, we show that in cultured motor neurons GABA-induced currents are significantly altered following activation of GABA receptors coinciding with changes in membrane potential. Changes in intracellular chloride concentration constituted the mechanism for this modulation. Because of low resting chloride conductance and low activity of chloride transporters, changes in intracellular chloride concentration and hence GABA response were long-lasting (time constant of recovery was about 2.5 min). Cultured dorsal horn and hippocampal neurons exhibited a similar response pattern, suggesting a general property of cultured neuronal cells. These long-lasting changes in GABA responsiveness may have major implications on neuronal excitability.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Chlorides / metabolism
  • Hippocampus / physiology
  • Membrane Potentials / drug effects
  • Motor Neurons / metabolism*
  • Neural Inhibition / physiology
  • Patch-Clamp Techniques
  • Posterior Horn Cells / physiology
  • Rats
  • Rats, Wistar
  • gamma-Aminobutyric Acid / metabolism*
  • gamma-Aminobutyric Acid / pharmacology

Substances

  • Chlorides
  • gamma-Aminobutyric Acid