Sound-evoked deflections of outer hair cell stereocilia arise from tectorial membrane anisotropy.

ABSTRACT: The exceptional performance of mammalian hearing is due to the cochlea's amplification of sound-induced mechanical stimuli. During acoustic stimulation, the vertical motion of the outer hair cells relative to the tectorial membrane (TM) is converted into the lateral motion of their stereocilia. The actual mode of this conversion, which represents a fundamental step in hearing, remains enigmatic, as it is unclear why the stereocilia are deflected when pressed against the TM, rather than penetrating it. In this study we show that deflection of the stereocilia is a direct outcome of the anisotropic material properties of the TM. Using force spectroscopy, we find that the vertical stiffness of the TM is significantly larger than its lateral stiffness. As a result, the TM is more resistant to t

SUBMITTER: Gueta R 

PROVIDER: S-EPMC2480654 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature