High-frequency motility of outer hair cells and the cochlear amplifier

摘要: Outer hair cells undergo somatic elongation-contraction cycles in vitro when electrically stimulated. This "electromotile" response is assumed to underlie the high sensitivity and frequency selectivity of amplification mammalian cochlea. process, presumably operating on a cycle-by-cycle basis at stimulus, believed provide mechanical feedback vivo. However, if driven by receptor potential cell, expected be severely attenuated frequencies because electrical low-pass filtering outer cell basolateral membrane. It proposed that electromotility instead extracellular gradients across it shown this driving voltage not subject sufficiently large. further properties membrane are canceled, taking advantage characteristics isolated partitioning glass microchamber, then lower bound motor's bandwidth approximately 22 kilohertz, number determined only limitations our instrumentation.