Expression of GABA A receptor subunits in the rat central nucleus of the inferior colliculus

Abstract

Expression of GABA A receptor (GABA AR) α 1, α 2, β 2, γ 1, γ 2L and γ 2S subunit mRNA was examined in three cell classes in the central nucleus of the rat inferior colliculus (CNIC). GABA AR α 1 and γ 2L subunit mRNA expression was greatest in large cells (over 25 μm long diameter), intermediate in medium sized cells (15 to 25 μm long diameter) and lowest in small cells (10 to 15 μm long diameter). GABA AR γ 2S and α 2 subunits had the opposite pattern, highest in the small cells, intermediate in medium cells and lowest in large cells. GABA AR β 2 was significantly lower in small cells than the two other classes, while differences between large and medium cells were not significant. GABA AR γ 1 subunit mRNAs expression was not above background in any of the three cell types assessed. The expression of GABA AR subunits suggests that cell classes in the rat CNIC may differ in their response to GABA and GABAergic drugs.