Ca2+-mediated suppression of the GABA-response through modulation of chloride channel gating in frog sensory neurones

Neurosci Lett. 1988 Apr 12;86(3):311-6. doi: 10.1016/0304-3940(88)90502-2.

Abstract

A suppressant effect of intracellular free Ca2+ on the gamma-aminobutyric acid (GABA)-induced chloride inward current (ICI(GABA)) was studied in isolated frog sensory neurones under whole cell voltage clamp. Voltage-dependent Ca2+ influx elicited during the steady state of ICI(GABA)-induced a fast, slowly recovering current relaxation in the outward direction, the amplitude of which was dependent on total Ca2+ influx. This suppressant effect showed specificity for different divalent cations, suggesting action at a specific intracellular effector. Single channel recording revealed a Ca2+-dependent decrease in the duration of the open time of the GABA-gated Cl- channel without change in single channel conductance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / pharmacology*
  • Chlorides / metabolism
  • Chlorides / physiology*
  • Ganglia, Spinal / drug effects
  • Ganglia, Spinal / physiology*
  • In Vitro Techniques
  • Ion Channels / metabolism
  • Ion Channels / physiology*
  • Membrane Potentials / drug effects
  • Neurons, Afferent / drug effects
  • Neurons, Afferent / physiology*
  • Rana catesbeiana
  • gamma-Aminobutyric Acid / pharmacology*

Substances

  • Chlorides
  • Ion Channels
  • gamma-Aminobutyric Acid
  • Calcium