Cp. Miralles et al., DIFFERENTIAL EXPRESSION OF THE SHORT AND LONG FORMS OF THE GAMMA(2) SUBUNIT OF THE GABA(A) BENZODIAZEPINE RECEPTORS, Molecular brain research, 24(1-4), 1994, pp. 129-139
The distribution of the mRNAs encoding the gamma(2S) and gamma(2L) sub
units of the GABA(A) receptor in the rat brain has been revealed by in
situ hybridization, northern blot and dot blot analysis using specifi
c antisense oligonucleotides. In addition, the quantitative distributi
on of the gamma(2S) and gamma(2L) subunit peptides participating in th
e fully assembled GABA(A) receptors/benzodiazepine receptors has been
mapped by immunoprecipitation with specific anti-gamma(2S) and anti-ga
mma(2L) antibodies. Several neuronal types and brain regions are enric
hed in gamma(2L) such as neurons of the layer II of striate cortex and
cerebellar Purkinje cells as well as the inferior colliculus, superio
r colliculus, deep cerebellar nuclei, medulla and pens. Other neuronal
types and regions are enriched in gamma(2S) such as the mitral cells
of the olfactory bulb, pyramidal neurons of the pyriform cortex, layer
VI of the neocortex, granule cells of the dentate gyrus and pyramidal
cells of the hippocampus. Other cortical areas and cerebellar granule
cells express both gamma(2S) and gamma(2L) in comparable amounts. The
re is a good correlation between the relative expression of gamma(2S)
and gamma(2L) mRNAs and the relative presence of these protein subunit
s in fully assembled and mature receptors in the studied brain regions
. The differential distribution of gamma(2S) and gamma(2L) might resul
t in differential ethanol sensitivity of the neurons expressing these
GABA(A) receptor subunits.