High-frequency electromotile responses in the cochlea.
Mammalian outer hair cells (OHCs) convert electrical energy into mechanical energy. The significance of this electromotility rests in the ability of the OHCs to modulate the vibrations of the cochlear partition in vivo. While high-frequency electromotility of isolated OHCs has been demonstrated at frequencies up to 100 kHz, a similar measure of the effect of OHC electromotility on motion of the sensory epithelium has not been made in vivo. In this study, in vivo electrical stimulation of the guinea pig cochlea is found to induce a mechanical response of the basilar membrane for frequencies to at least 100 kHz, nearly twice the upper limit of hearing for the guinea pig. The perfusion of salicylate in the cochlea reversibly reduces the electromotile response, indicating that an OHC-mediated process is the key contributor.
Grosh
Karl
K
Department of Mechanical Engineering, The University of Michigan, 3124 G.G. Brown Building, Ann Arbor, Michigan 48109-2125, USA.
Zheng
Jiefu
J
Zou
Yuan
Y
de Boer
Egbert
E
Nuttall
Alfred L
AL
D000161:Acoustic Stimulation; D000818:Animals; D001489:Basilar Membrane / Q000502:physiology; D003051:Cochlea / Q000502:physiology*; D004558:Electric Stimulation; D004594:Electrophysiology; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000502:physiology; D010897:Pitch Discrimination; D010898:Pitch Perception