The Nonlinearity of Outer Hair Cell Motility: Implications for Cochlear Physiology and Pathology

  • Burt N. Evans
  • Richard Hallworth
  • Peter Dallos
Part of the Lecture Notes in Biomathematics book series (LNBM, volume 87)


It is now clear that the motile responses of isolated outer hair cells (OHCs) in vitro are nonlinear (Evans, 1988; Evans et al., 1989, 1990; Santos-Sacchi, 1989). To further our understanding of the nonlinearity and its physiological significance, we have developed a novel preparation (Evans et al., 1989) that offers several improvements over methods previously used in motility studies. Isolated guinea pig OHCs were prepared by enzymatic digestion in papain followed by gentle trituration. The experimental medium, Leibovitz’s L-15 (Gibco), was buffered with 15 mM HEPES, and adjusted to pH 7.35, 320 mOsm. Cells were drawn up by gentle suction into a glass pipette that was heat-polished to a diameter close to that of a hair cell (Fig. 1). The pipette made a resistive seal with the cell body, forming a microchamber. Voltage commands were applied across the cell and the preparation resistance monitored using a current-to-voltage converter. Isolated OHCs were maintained in a separate reservoir and individually transferred to the experimental chamber using a wide-bore suction pipette.


Hair Cell Rest Membrane Potential Outer Hair Cell Voltage Command Contraction Direction 
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Copyright information

© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • Burt N. Evans
    • 1
  • Richard Hallworth
    • 1
  • Peter Dallos
    • 1
  1. 1.Auditory Physiology Laboratory (the Hugh Knowles Center) and Department of Neurobiology and PhysiologyNorthwestern UniversityEvanstonUSA

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