Functional role of Ca2+ currents within the stereocilia as bio-MEMS: A modeling study

Hair cells are thought to be passive transduction systems able to convert a mechanical pulse in an electrical signal. In this paper, we have investigated the polyelectrolyte properties of actin filaments which in interaction with myosin motor proteins represent basic participants in mechano-electrical transduction in the stereocilia, mechanosensing organelles of hair cells. We have elaborated a biophysical model with the aim to explain how actin filaments play the role of guides for propagation of Ca
²⁺
ion currents. Special emphasis is placed on the possible role of this mechanism in tuning the activity of myosin motors which are involved in mechanosensitivity of the stereocilia.