Cell
Volume 79, Issue 4, 18 November 1994, Pages 705-715
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Article
α9: An acetylcholine receptor with novel pharmacological properties expressed in rat cochlear hair cells

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Abstract

We report the isolation and functional characterization of a member of the nicotinic acetylcholine receptor subunit gene family, α9. Xenopus oocytes injected with α9 cRNA express a homomeric receptor-channel complex that is activated by acetylcholine. The α9 receptor displays an unusual mixed nicotinic-muscarinic pharmacological profile. The unique properties of the α9 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 α9 gene expression that includes the outer hair cells of the rat cochlea. Our results suggest that the α9 receptor is involved in the cholinergic efferent innervation of cochlear hair cells and thus may modulate the encoding of auditory stimuli.

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    Present address: Instituto de Investigaciones Farmacológicas, Junín 956, 5 Piso, Buenos Aires 1113, Argentina.

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