Downregulation of GABA(A) β subunits is transcriptionally controlled by Fmr1p

Fragile X mental retardation syndrome is caused by the transcriptional silence of FMR1. Here, a quantitative PCR technique was used to examine the effect of Fmr1p on the expression of GABA(A) β subunits in different mouse brain regions. Our results demonstrated the reduction of GABA(A) β2 mRNA in all brain regions assessed, and the reduction of GABA(A) β3 mRNA in the cortex, suggesting that the expression of GABA(A) β subunits is transcriptionally regulated by Fmr1p. This finding may help to establish the link between the transcriptional profile of the GABAergic inhibitory system and the development of fragile X mental retardation syndrome.