TY - JOUR
T1 - Furosemide alters organ of Corti mechanics
T2 - Evidence for feedback of outer hair cells upon the basilar membrane
AU - Ruggero, Mario A.
AU - Rich, Nola C.
PY - 1991
Y1 - 1991
N2 - A widely held hypothesis of mammalian cochlear function is that the mechanical responses to sound of the basilar membrane depend on transduction by the outer hair cells. We have tested this hypothesis by studying the effect upon basilar membrane vibrations (measured by means of either the Mossbauer technique or Doppler-shift laser velocimetry) of systemic injection of furosemide, a loop diuretic that decreases transduction currents in hair cells. Furosemide reversibly altered the responses to tones and clicks of the chinchilla basilar membrane, causing response-magnitude reductions that were largest (up to 61 dB, averaging 25-30 dB) at low stimulus intensities at the characteristic frequency (CF) and small or nonexistent at high intensities and at frequencies far removed from CF. Furosemide also induced response-phase lags that were largest at low stimulus intensities (averaging 77°) and were confined to frequencies close to CF. These results constitute the most definitive demonstration to date that mechanical responses of the basilar membrane are dependent on the normal function of the organ of Corti and strongly implicate the outer hair cells as being responsible for the high sensitivity and frequency selectivity of basilar membrane responses. A corollary of these findings is that sensorineural hearing deficits in humans due to outer hair cell loss reflect pathologically diminished vibrations of the basilar membrane.
AB - A widely held hypothesis of mammalian cochlear function is that the mechanical responses to sound of the basilar membrane depend on transduction by the outer hair cells. We have tested this hypothesis by studying the effect upon basilar membrane vibrations (measured by means of either the Mossbauer technique or Doppler-shift laser velocimetry) of systemic injection of furosemide, a loop diuretic that decreases transduction currents in hair cells. Furosemide reversibly altered the responses to tones and clicks of the chinchilla basilar membrane, causing response-magnitude reductions that were largest (up to 61 dB, averaging 25-30 dB) at low stimulus intensities at the characteristic frequency (CF) and small or nonexistent at high intensities and at frequencies far removed from CF. Furosemide also induced response-phase lags that were largest at low stimulus intensities (averaging 77°) and were confined to frequencies close to CF. These results constitute the most definitive demonstration to date that mechanical responses of the basilar membrane are dependent on the normal function of the organ of Corti and strongly implicate the outer hair cells as being responsible for the high sensitivity and frequency selectivity of basilar membrane responses. A corollary of these findings is that sensorineural hearing deficits in humans due to outer hair cell loss reflect pathologically diminished vibrations of the basilar membrane.
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U2 - 10.1523/jneurosci.11-04-01057.1991
DO - 10.1523/jneurosci.11-04-01057.1991
M3 - Article
C2 - 2010805
AN - SCOPUS:0026046327
SN - 0270-6474
VL - 11
SP - 1057
EP - 1067
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 4
ER -