Expression of gamma-aminobutyric acid(A) receptor subunits in the vestibular system

Objectives: Profile the expression of genes encoding GABA(A) receptor subun its in the vestibular end organs of a rat. Materials and Methods: Using a c ombination of reverse transcription followed by polymerase chain reaction ( PCR) with gene-specific primers, expression of mRNAs encoding 13 individual GABA(A) receptor subunits was examined. Results: PCR amplification product s representing subunit gene expression for alpha 1-6, beta 1-3, and gamma 1 -3, but not for delta, subunits were amplified, suggesting multiple molecul ar levels of regulation of vestibular GABA(A) receptor expression. Nucleoti de sequencing confirmed the identity of rat vestibular end-organs subunit c DNAs. Conclusion: These results give the most direct evidence to date that GABA(A) receptors composed of the detected subunits are expressed in the ma mmalian vestibular system, giving new support to previous investigations im plicating GABA as a vestibular neurotransmitter.