New tunes from Corti's organ: the outer hair cell boogie rules.
The amplification of acoustic stimuli is a feature of hair cells that evolved early on in vertebrates. Though standard stereocilia mechanisms to promote such amplification may persist in the mammal, an additional mechanism evolved to enhance high frequency sensation. Only in mammals, a special cell type, the outer hair cell, arose that possesses a remarkably fast somatic mechanical response, which probably endows the passive cochlea with a boost in sensitivity by a factor of 100 (40dB), at least. Experiments conducted over the past few years have shed light on many aspects of outer hair cell electromotility, including the molecular identification of the motor, the effects of a knockout, and underlying mechanisms of action. A review of this remarkable progress is attempted.
Santos-Sacchi
Joseph
J
Yale University School of Medicine, Otolaryngology and Neurobiology, BML 244 333 Cedar Street, New Haven, CT 06510, USA. joseph.santos-sacchi@yale.edu
D000161:Acoustic Stimulation / Q000379:methods*; D000818:Animals; D027321:Anion Transport Proteins; D018072:Hair Cells, Auditory, Outer / Q000502:physiology*; D006801:Humans; D008564:Membrane Potentials / Q000502:physiology; D009925:Organ of Corti / Q000502:physiology; D011506:Proteins / Q000502:physiology; D000076988:Sulfate Transporters
D027321:Anion Transport Proteins; D011506:Proteins; C498719:SLC26A5 protein, human; D000076988:Sulfate Transporters