title: Desensitization characteristics of rat recombinant GABA(A) receptors consisting of alpha1beta2gamma2S and alpha1beta2 subunits expressed in HEK293 cells.
abstract: Desensitization kinetics of rat recombinant typeA GABAergic receptors consisting of the subunits alpha1beta2gamma2S or alpha1beta2 was investigated on application of 10-0.001 mM GABA to whole cell patches using a piezo driven liquid filament switch for fast application and deapplication. At high GABA concentrations desensitization was triphasic showing increasing time constants and a decreasing extent of desensitization on lowering the GABA concentration. Below agonist concentrations of 1 mM for the trimeric receptor and 0.1 mM for the dimeric one desensitization was biphasic switching to monophasic kinetics at GABA concentrations < or = 0.01 mM for the alpha1beta2gamma2S-type and < or = 0.003 mM for the alpha1beta2-type, respectively. Comparison with former studies performed with GABAergic receptors consisting of different subunits revealed differences in the desensitization kinetics.
authors.affiliation: Department of Neurology of the Medical Department, Medizinische Hochschule Hannover, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Krampfl
authors.forename: J
authors.initials: J
authors.lastname: Bufler
authors.forename: A
authors.initials: A
authors.lastname: Lepier
authors.forename: J
authors.initials: J
authors.lastname: Dudel
authors.forename: H
authors.initials: H
authors.lastname: Adelsberger
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D018408:Patch-Clamp Techniques; D011487:Protein Conformation; D051381:Rats; D011963:Receptors, GABA-A / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D011963:Receptors, GABA-A; D011993:Recombinant Fusion Proteins; D005680:gamma-Aminobutyric Acid