Objectives: Profile the expression of genes encoding GABAA receptor subunits in the vestibular end organs of a rat.
Materials and methods: Using a combination 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 products representing subunit gene expression for alpha1-6, beta1-3, and gamma1-3, but not for delta, subunits were amplified, suggesting multiple molecular levels of regulation of vestibular GABA(A) receptor expression. Nucleotide sequencing confirmed the identity of rat vestibular end-organs subunit cDNAs.
Conclusion: These results give the most direct evidence to date that GABAA receptors composed of the detected subunits are expressed in the mammalian vestibular system, giving new support to previous investigations implicating GABA as a vestibular neurotransmitter.