Antibodies were raised against specific peptides from N-terminal regions of
the alpha (1) and alpha (3) isoforms of the GABA(A) receptor, and used to
assess the relative expression of these proteins in the superior frontal an
d primary motor cortices of 10 control, nine uncomplicated alcoholic and si
x cirrhotic alcoholic cases were matched for age and post-mortem delay. The
regression of expression on post-mortem delay was not statistically signif
icant for either isoform in either region. In both cortical areas, the regr
ession of a, expression on age differed significantly between alcoholic cas
es, which showed a decrease, and normal controls, which did not. Age had no
effect on alpha (3) expression. The alpha (1) and alpha (3) isoforms were
found to be expressed differentially across cortical regions and showed a t
endency to be expressed differentially across case groups. In cirrhotic alc
oholics, alpha (1) expression was greater in superior frontal than in motor
cortex, whereas this regional difference was not significant in controls o
r uncomplicated alcoholics. In uncomplicated alcoholics, alpha (3) expressi
on was significantly lower in superior frontal than in motor cortex. Expres
sion of alpha (1) was significantly different from that Of alpha (3) in the
superior frontal cortex of alcoholics, but not in controls. In motor corte
x, there were no significant differences in expression between the isoforms
in any case group.