title: The voltage dependence of GABAA receptor gating depends on extracellular pH.
abstract: Recent studies have indicated that changes in extracellular pH and in membrane voltage affect the gamma-amino-n-butyric acid type A receptor gating mainly by altering desensitization and binding. To test whether the effects of membrane potential and pH are additive, their combined actions were investigated. By analyzing the current responses to rapid gamma-amino-n-butyric acid applications, we found that the current to voltage relationship was close to linear at acid pH but the increasing pH induced an inward rectification. Desensitization was enhanced at depolarizing potentials, but this strongly depended on pH, being weak at acidic and strong at basic pH values. A similar trend was observed for the onset rate of responses to saturating gamma-amino-n-butyric acid concentration. These data provide evidence that the voltage sensitivity of GABAA receptors depends on extracellular pH.
authors.affiliation: Laboratory of Neuroscience, Department of Biophysics, Wroclaw Medical University, Wroclaw, Poland. maja@biofiz.am.wroc.pl
authors.forename: Maria
authors.initials: M
authors.lastname: Pytel
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Mercik
authors.forename: Jerzy W
authors.initials: JW
authors.lastname: Mozrzymas
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005110:Extracellular Space / Q000378:metabolism; D018682:GABA Agents / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology; D006863:Hydrogen-Ion Concentration; D015640:Ion Channel Gating / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
chemical_list: D018682:GABA Agents; D011963:Receptors, GABA-A; D005680:gamma-Aminobutyric Acid