Mechanical stresses and forces in stereocilia bundles of inner and outer hair cells

The precise mechanism of mechanoelectrical transduction in stereocilia bundles is not known. it is very difficult to measure the extremely small stresses, which occur at the stereocilia bundles. Therefore we developed 3-D finite element models of stereocilia bundles (guinea pig) to obtain quantitative results. The stereocilia bundles of the outer hair cells show a characteristic W-form. Therefore, it is interesting to compare the mechanical behavior of the stereocilia bundle of an outer hair cell with that of an inner hair cell with its linear arrangement. Our analysis provides estimates of forces and stresses on the transducer channels of mammalian hair bundles, although the model does not include active mechanisms yet.