a9: an acetylcholine receptor with novel pharmacological properties expressed in rat cochlear hair cells

ELGOYHEN AB; JOHNSON D; BOULTER J; VETTER D; HEINEMANN S

CELL

CELL PRESS

Lugar: United States; Año: 1994 vol. 79 p. 705 - 715

0092-8674

We report the isolation and functional characterization of a member of the nicotinic acetylcholine receptor subunit gene family, cc9. Xenopus oocytes injected with a9 cRNA express a homomeric receptor-channel complex that is activated by acetylcholine. The a9 receptor displays an unusual mixed nicotinic-muscarinic pharmacological profile. The unique properties of the a9 receptor-channel complex closely match those described for the cholinergic receptor present in vertebrate cochlear hair cells. In situ hybridization studies reveal a restricted pattern of a9 gene expression that includes the outer hair cells of the rat cochlea. Our results suggest that the cc9 receptor is involved in the cholinergic efferent innervation of cochlear hair cells and thus may modulate the encoding of auditory stimuli.