Send to

Choose Destination
Neuron. 1999 May;23(1):93-103.

Role of alpha9 nicotinic ACh receptor subunits in the development and function of cochlear efferent innervation.

Author information

The Salk Institute for Biological Studies, La Jolla, California 92037, USA.


Cochlear outer hair cells (OHCs) express alpha9 nACh receptors and are contacted by descending, predominately cholinergic, efferent fibers originating in the CNS. Mice carrying a null mutation for the nACh alpha9 gene were produced to investigate its role(s) in auditory processing and development of hair cell innervation. In alpha9 knockout mice, most OHCs were innervated by one large terminal instead of multiple smaller terminals as in wild types, suggesting a role for the nACh alpha9 subunit in development of mature synaptic connections. Alpha9 knockout mice also failed to show suppression of cochlear responses (compound action potentials, distortion product otoacoustic emissions) during efferent fiber activation, demonstrating the key role alpha9 receptors play in mediating the only known effects of the olivocochlear system.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center