Gramicidin perforated patch-clamp technique reveals glycine-gated outward chloride current in dissociated nucleus solitarii neurons of the rat

J Neurophysiol. 1994 Sep;72(3):1103-8. doi: 10.1152/jn.1994.72.3.1103.


1. The inhibitory response of exogenously applied glycine was investigated in freshly dissociated rat nucleus tractus solitarii neurons under whole cell configuration using new perforated patch-clamp technique termed "gramicidin perforated patch technique," which maintains intact intracellular Cl- concentrations. 2. Using the gramicidin perforated patch technique, at a holding potential (VH) of -45 mV, glycine induced outward currents in a concentration-dependent manner with a EC50 of 4.0 x 10(-5) M and at a Hill coefficient of 1.5. In contrast, using the nystatin perforated patch technique, glycine induced inward currents at the same VH in a concentration-dependent manner with an EC50 of 4.9 x 10(-5) M and at a Hill coefficient of 1.2. 3. The glycine-induced outward currents were blocked by strychnine in a concentration dependent manner with an IC50 of 2.2 x 10(-8) M. The blockade was competitive. 4. The current-voltage relationship for the 10(-5) M glycine response showed a clear outward rectification. 5. Ten-fold change of extracellular Cl- with a large impermeable anion resulted in a 65 mV shift of the reversal potential of glycine-induced currents (EGly), indicating that the membrane behaves like a Cl- electrode in the presence of glycine. 6. The intracellular Cl- activity calculated from the EGly ranged from 7.3 to 18.2 mM, with a mean value of 13.3 mM. 7. The values of EGly in the individual neurons were significantly negative to the resting membrane potentials, suggesting the existence of active transport of Cl-.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chloride Channels / drug effects*
  • Chloride Channels / physiology
  • Culture Techniques
  • Female
  • Glycine / physiology*
  • Gramicidin / pharmacology*
  • Male
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Neural Inhibition / drug effects*
  • Neural Inhibition / physiology
  • Neurons / drug effects
  • Neurons / physiology
  • Rats
  • Rats, Wistar
  • Solitary Nucleus / drug effects*
  • Solitary Nucleus / physiology
  • Synaptic Transmission / drug effects*


  • Chloride Channels
  • Gramicidin
  • Glycine