Static length changes of cochlear outer hair cells can tune low-frequency hearing
Fig 2
Predicted motion of the Hensen cells for different parameter values.
(A) We characterize the motion of the Hensen cells through the radial and vertical displacements of two points on the top and on the side of the Hensen-cell contour (red stars). (B) The motion pattern predicted by our model through comparison with experimental data involves large displacement of the Hensen cells as well as of the base of the outer hair cells way from the basilar membrane upon outer hair cell contraction. The basilar membrane is assumed to be fixed. (C-F) Vertical and radial displacement of the two points on the Hensen-cell contour for a hair-cell contraction ϵ = 0.005 and different choices of the mode parameters Δ and Γ. The parameter values that are identified as biologically realistic through comparison with experimental data are indicated through an asterisk and are used in (B). (C) The top of the organ consistently moves away from the basilar membrane when the outer hair cells contract. (D) The radial displacement of the upper point shows a more complex behaviour: both motion towards and away from the stria vascularis can occur under outer hair cell contraction, depending on the values of the model parameters. (E-F) The direction of both the vertical and the radial motion of the lateral point depend on the values of the model parameters as well. However, this motion was not experimentally accessible.