Molecular mechanisms of sound amplification in the mammalian cochlea

Molecular mechanisms of sound amplification in the mammalian cochlea

Department of Physiology, University College London, Gower Street, London WC1E 6BT, United Kingdom

Abstract

Mammalian hearing depends on the enhanced mechanical properties of the basilar membrane within the cochlear duct. The enhancement arises through the action of outer hair cells that act like force generators within the organ of Corti. Simple considerations show that underlying mechanism of somatic motility depends on local area changes within the lateral membrane of the cell. The molecular basis for this phenomenon is a dense array of particles that are inserted into the basolateral membrane and that are capable of sensing membrane potential field. We show here that outer hair cells selectively take up fructose, at rates high enough to suggest that a sugar transporter may be part of the motor complex. The relation of these findings to a recent candidate for the molecular motor is also discussed.

Footnotes

↵ * To whom reprint requests should be addressed. E-mail: j.ashmore{at}ucl.ac.uk.
↵ † Present address: Harvard Medical School, Massachusetts General Hospital, Howard Hughes Medical Institute, Wellman 414, Boston, MA 02114.
This paper was presented at the National Academy of Sciences colloquium “Auditory Neuroscience: Development, Transduction, and Integration,” held May 19–21, 2000, at the Arnold and Mabel Beckman Center in Irvine, CA.
Abbreviation:

OHC,

outer hair cell