Gene expression of P2X-receptors in the developing inner ear of the rat

Reverse transcription-polymerase chain reaction (RT-PCR) was used to charac terize the expression of P2X receptor subunits (P2X(1)-P2X(7)) in different inner ear tissues. The present study revealed the presence of P2X(2), P2X( 3), P2X(4) and P2X(7)-mRNA in rat organ of Corti, vestibular organ and spir al ganglion at different postnatal developmental stages (PD1-PD16), with sl ight differences in the onset of expression. Expression of P2X(1), P2X(5) a nd P2X(6)-mRNA was not detectable in the inner ear tissues. In addition, si ngle cell RT-PCR experiments with outer hair cells (OHC) revealed the expre ssion of either the P2X(2) or the P2X(2-2) splice variant or coexpression o f both isoforms in individual cells. Our data suggest that extracellular ad enosine-5'-triphosphate (ATP) may play an important role in signal transduc tion in the inner ear. (C) 1999 Elsevier Science ireland Ltd. All rights re served.