Feb 24, 1987

gamma-Aminobutyric acid opens Cl-channels in cultured astrocytes

Brain Research
H KettenmannM Schachner

Abstract

Cultured astrocytes from cerebral hemispheres of early postnatal rats responded to gamma-aminobutyric acid (GABA) with membrane depolarization. This depolarization was affected by changes in extracellular [Cl-] and depended on the membrane potential. The reversal potential of the GABA-induced depolarization was determined by double electrode voltage clamp or depolarization by elevated [K+]o and ranged between -38 and -53 mV. Cell input resistance decreased after addition of GABA with the same time course as the membrane depolarization. GABA responses were temperature dependent yielding a peak at about 14 degrees C. At higher temperatures a decrease in the GABA-induced depolarization was seen indicating that the depolarization may not be mediated by an enzyme-coupled carrier system. Addition of ouabain at different temperatures did not change the size of the GABA depolarization. This excludes the possibility that an electrogenic component of the temperature-sensitive Na+,K+-ATPase activity causes the decrease in GABA-dependent depolarization at higher temperatures. Intracellular [Cl-] was measured with Cl- sensitive microelectrodes and found to be higher than the value calculated for a free distribution according to the Nernst e...Continue Reading

  • References7
  • Citations82

Mentioned in this Paper

Chloride Ion Level
Extracellular
Protoplasm
August Rats
Astrocytes
Ouabain
PDZK1 gene
Salix - substance
Electric Conductivity
Cortical Cell Layer of the Cerebral Cortex

About this Paper

Related Feeds

Cell Adhesion Molecules in AS

Cell adhesion molecules expressed on the vascular endothelium and circulating leukocytes in response to inflammatory stimuli are implicated in atherosclerosis. Here is the latest research.

Astrocytes

Astrocytes are glial cells that support the blood-brain barrier, facilitate neurotransmission, provide nutrients to neurons, and help repair damaged nervous tissues. Here is the latest research.