Expression of the α1, α2 and α3 isoforms of the GABA A receptor in human alcoholic brain

Abstract

The expression of the α 1, α 2 and α 3 isoforms of the GABA A receptor was studied in the superior frontal and motor cortices of 10 control, 10 uncomplicated alcoholic and 7 cirrhotic alcoholic cases matched for age and post-mortem delay. The assay was based on competitive RT/PCR using a single set of primers specific to the α class of isoform mRNA species, and was normalized against a synthetic cRNA internal standard. The assay was shown to be quantitative for all three isoform mRNA species. Neither the patient's age nor the post-mortem interval significantly affected the expression of any isoform in either cortical area. The profile of expression was shown to be significantly different between the case groups, particularly because α 1 expression was raised in both groups of alcoholics cf controls. The two groups of alcoholics could be differentiated on the basis of regional variations in α 1 expression. In frontal cortex, α 1 mRNA expression was significantly increased when uncomplicated alcoholics were compared with control cases whereas alcoholic-cirrhotic cases were not significantly different from either controls or uncomplicated alcoholic cases. In the motor cortex, α 1 expression was elevated only when alcoholic-cirrhotic cases were compared with control cases. There was no significant difference between case groups or areas for any other isoform. © 1997 Elsevier Science B.V. All rights reserved.