Differential expression of α 2-7, α9 and β2-4 nicotinic acetylcholine receptor subunit mRNA in the vestibular end-organs and Scarpa's ganglia of the rat

To further characterize the pattern of expression of the nicotinic acetylcholine receptor (nAChR) subunits in the peripheral vestibular system, we conducted RT-PCR of all known mammalian nAChR α and β subunits in mRNA extracted from adult rat vestibular primary afferent neurons (Scarpa's ganglia) and vestibular end-organs. Transcripts encoding the α2-7 and β2-4 nAChR subunits were found in the vestibular ganglia, while α3, α5-7, α9 and β2-4 nAChR subunits were expressed in the vestibular end-organs. These results support previous electrophysiological, immunocytochemical and molecular biological data, and also provide a more complete understanding of the role of nAChRs in the neurochemical transmission subserving the efferent- afferent interaction in the vestibular periphery.