Dynamic study of tip-link tension and stereocilia motion in cochlea

Explanation of cochlear active acoustic amplification mechanism has been an unsolved medical problem. This is closely related to the motion stereocilia at top outer hair cells in cochlea. The regulated by tip-link tension and fluid force lymph fluid. Therefore, studying during important part explanation cochlea's sensory sound mechanism. Most previous studies regarded as rigid bodies, ignored influence shaft bending when mechanical properties bundle. researches on elastic used finite element simulation, or simplified model ignoring fluid-solid coupling with fluid, considered only static loading. Based Poiseuille flow combined distributed parameter model, analytical solution derived this work. dynamic response under shear tectorial membrane change law are studied. produces a nonlinear accumulation displacement height stereocilia. higher stereocilia, more obvious effect is. Under action load, contributes most tall stereocilium, contribution easily affected frequency change. low stereocilium comes mainly from root deflection. At high frequency, increases significantly, produced combination F-actin content cochlea exposed noise would affect stiffness. In paper, it found that decrease stereociliary Young's modulus will increase peak value normalized reduce its amplitude load. Since connected ion channel, probability channels opening, ability perceive corresponding then selectivity bodies underestimated low-frequency signals. accurately describes provides theoretical for hearing impairment caused environment. Previous experiments have shown lymphatic viscous resistance little deflection ignored, changes very little, pressure between significantly resonance <inline-formula><tex-math id="M4">\begin{document}$ {f_2} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="4-20211105_M4.jpg"/><graphic xlink:href="4-20211105_M4.png"/></alternatives></inline-formula> disappears. regulates creating presence lymphatics essential generating characteristics domain, tip-link, pressure.