GABAA-receptors: drug binding profile and distribution of receptors containing the alpha 2-subunit in situ

J Recept Res. 1993;13(1-4):467-77. doi: 10.3109/10799899309073673.


The highest structural diversity of GABAA-receptor subunits is observed among members of the alpha-subunit class. Using subunit-specific antisera, the receptors containing the alpha 2-subunit were characterized. Western blots revealed an apparent molecular size of 52 kDa for the alpha 2-subunit. Immunohistochemically, the alpha 2-subunit was most preponderant in areas which lack the alpha 1-subunit, e.g. striatum and olfactory bulb granule cell layer, suggesting that these two subunits represent largely distinct receptor subtypes. Pharmacologically, the receptor population which was immunoprecipitated by the alpha 2-subunit-specific antisera displayed a drug binding profile characterized by a low affinity for CL 218872, beta CCM and zolpidem. This is in striking contrast to the high affinities of these ligands displayed by receptors immunoprecipitated by the alpha 1-subunit-specific antiserum. Thus, the alpha 1- and the alpha 2-subunit characterize two GABAA-receptor populations which greatly differ in brain distribution and pharmacological profile.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibody Specificity
  • Immune Sera / immunology
  • Immunoenzyme Techniques
  • Molecular Sequence Data
  • Peptide Fragments / immunology
  • Peptide Fragments / metabolism
  • Precipitin Tests
  • Radioligand Assay
  • Rats
  • Receptors, GABA-A / immunology
  • Receptors, GABA-A / metabolism*


  • Immune Sera
  • Peptide Fragments
  • Receptors, GABA-A