title: Subunit composition and quantitative importance of GABA(A) receptor subtypes in the cerebellum of mouse and rat.
abstract: In cerebellum, 13 different GABA(A) receptor subunits are expressed. The number of different receptor subtypes formed in this tissue, their subunit composition and their quantitative importance so far has not been determined. In the present study, immunodepletion by immunoaffinity chromatography, as well as immunoprecipitation and western blot analysis was performed using 13 different subunit-specific antibodies to provide an overview on the subunit composition and abundance of GABA(A) receptor subtypes in mouse and rat cerebellum. Results obtained indicate that alpha1betaxgamma2, alpha1alpha6betaxgamma2, alpha6betaxgamma2, alpha6betaxdelta and alpha1alpha6betaxdelta are the major GABA(A) receptor subtypes present in the cerebellum. In addition, small amounts of alpha1betaxdelta receptors and a series of minor receptor subtypes containing alpha2, alpha3, alpha4, alpha5, gamma1 or gamma3 subunits are also present in the cerebellum. Whereas the abundance of alpha1alpha6betaxgamma2, alpha6betaxdelta and alpha1alpha6betaxdelta receptors is different in mouse and rat cerebellum, that of other receptors is quite similar in these tissues. Data obtained for the first time provide an overview on the GABA(A) receptor subtypes present in the cerebellum and represent the basis for further studies investigating changes in receptor expression and composition under pathological conditions.
authors.affiliation: Division of Biochemistry and Molecular Biology, Brain Research Institute, University of Vienna and Section of Biochemical Psychiatry, University Clinic for Psychiatry, Vienna, Austria.
authors.forename: Angelika
authors.initials: A
authors.lastname: Pöltl
authors.forename: Birgit
authors.initials: B
authors.lastname: Hauer
authors.forename: Karoline
authors.initials: K
authors.lastname: Fuchs
authors.forename: Verena
authors.initials: V
authors.lastname: Tretter
authors.forename: Werner
authors.initials: W
authors.lastname: Sieghart
mesh_terms: D000818:Animals; D000906:Antibodies / Q000378:metabolism; D015153:Blotting, Western / Q000379:methods; D002460:Cell Line; D002531:Cerebellum / Q000737:chemistry / Q000378:metabolism*; D002846:Chromatography, Affinity / Q000379:methods; D004622:Embryo, Mammalian; D006801:Humans; D007668:Kidney; D051379:Mice; D008810:Mice, Inbred C57BL; D009118:Muscimol / Q000493:pharmacokinetics; D011233:Precipitin Tests / Q000379:methods; D021122:Protein Subunits / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011869:Radioligand Assay / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D013045:Species Specificity; D014162:Transfection / Q000379:methods; D014316:Tritium / Q000493:pharmacokinetics
chemical_list: D000906:Antibodies; D021122:Protein Subunits; D011963:Receptors, GABA-A; D014316:Tritium; D009118:Muscimol