Multiple mechanisms of antagonism of gamma-aminobutyric acid (GABA) responses

Cell Mol Neurobiol. 1987 Mar;7(1):97-103. doi: 10.1007/BF00734993.


Gamma-aminobutyric acid (GABA) is one of the most important neurotransmitters in the brain. In an effort to understand the operation of the GABA receptor-ionophore complex, the antagonism of GABA responses by four substances was studied in bullfrog dorsal root ganglion cells by concentration-clamp and internal-perfusion techniques. Two antagonists (bicuculline and Zn2+) were competitive; two (picrotoxin and penicillin) were noncompetitive. However, significant changes in the kinetics of activation and inactivation were produced by the antagonists, including those that were competitive. The causes of these changes may be important clues to the structure and operation of the GABA receptor-ionophore complex.

Publication types

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

MeSH terms

  • Animals
  • Bicuculline / pharmacology*
  • Electric Conductivity
  • GABA Antagonists
  • Ganglia, Spinal / drug effects
  • Ganglia, Spinal / physiology*
  • In Vitro Techniques
  • Penicillins / pharmacology*
  • Picrotoxin / pharmacology*
  • Ranidae
  • Zinc / pharmacology*
  • gamma-Aminobutyric Acid / pharmacology*


  • GABA Antagonists
  • Penicillins
  • Picrotoxin
  • gamma-Aminobutyric Acid
  • Zinc
  • Bicuculline