Calcium Ions Promote Rapid Mechanically Evoked Movements of Hair Bundles

  • Fernán Jaramillo
  • J. Howard
  • A. J. Hudspeth
Part of the Lecture Notes in Biomathematics book series (LNBM, volume 87)


The mechanoreceptive organelle of a hair cell, the hair bundle, consists primarily of a bevelled array of hexagonally packed stereocilia. When a mechanical stimulus is applied at a bundle’s tip, the individual stereocilia behave as rigid rods that bend at their basal insertions into the cell’s apical surface. The 20 or so actin filaments that form the cytoskeleton in this tapered basal region probably contribute much of the bundle’s steadystate stiffness, which is approximately 1 mN·m−1 for the hair cells of amphibians (Howard and Ashmore, 1986; Howard and Hudspeth, 1987a; Denk el al., 1989), reptiles (Crawford and Fettiplace, 1985), and mammals (Flock and Strelioff, 1984; Russell et al., 1989).


Hair Cell Stimulus Probe Hair Bundle Calcium Effect Cochlear Hair Cell 
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Copyright information

© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • Fernán Jaramillo
    • 1
  • J. Howard
    • 2
  • A. J. Hudspeth
    • 1
  1. 1.Department of Cell Biology and NeuroscienceUniversity of Texas Southwestern Medical CenterDallasUSA
  2. 2.Department of Physiology and BiophysicsUniversity of Washington School of MedicineSeattleUSA

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