Reverse transduction measured in the isolated cochlea by laser Michelson interferometry

Mammano, Fabio; Ashmore, Jonathan

doi:10.1038/365838a0

Cited by 180 publications

(136 citation statements)

References 25 publications

Supporting

Mentioning

120

Contrasting

Unclassified

Order By: Relevance

“…At the same site and input level, the BM displacement is $0.32 lm. The large gain value implies that the BM vibrates with substantially less amplitude than the RL, as previously reported (Mammano and Ashmore 1993;Scherer et al 2003).…”

Section: Determination Of the Cochlear Amplifier Saturation Propertiesupporting

confidence: 72%

Otoacoustic Emissions from Residual Oscillations of the Cochlear Basilar Membrane in a Human Ear Model

Nobili

Vetešník

Turicchia

et al. 2003

JARO

Self Cite

View full text Add to dashboard Cite

Sounds originating from within the inner ear, known as otoacoustic emissions (OAEs), are widely exploited in clinical practice but the mechanisms underlying their generation are not entirely clear. Here we present simulation results and theoretical considerations based on a hydrodynamic model of the human inner ear. Simulations show that, if the cochlear amplifier (CA) gain is a smooth function of position within the active cochlea, filtering performed by a middle ear with an irregular, i.e., nonsmooth, forward transfer function suffices to produce irregular and long-lasting residual oscillations of cochlear basilar membrane (BM) at selected frequencies. Feeding back to the middle ear through hydrodynamic coupling afforded by the cochlear fluid, these oscillations are detected as transient evoked OAEs in the ear canal. If, in addition, the CA gain profile is affected by irregularities, residual BM oscillations are even more irregular and tend to evolve towards self-sustaining oscillations at the loci of gain irregularities. Correspondingly, the spectrum of transient evoked OAEs exhibits sharp peaks. If both the CA gain and the middle-ear forward transfer function are smooth, residual BM oscillations have regular waveforms and extinguish rapidly. In this case no emissions are produced. Finally, and paradoxically albeit consistent with observations, simulating localized damage to the CA results in self-sustaining BM oscillations at the characteristic frequencies (CFs) of the sites adjacent to the damage region, accompanied by generation of spontaneous OAEs. Under these conditions, stimulusfrequency OAEs, with typical modulation patterns, are also observed for inputs near hearing threshold. This approach can be exploited to provide novel diagnostic tools and a better understanding of key phenomena relevant for hearing science.

show abstract

Section: Determination Of the Cochlear Amplifier Saturation Propertiesupporting

confidence: 72%

Otoacoustic Emissions from Residual Oscillations of the Cochlear Basilar Membrane in a Human Ear Model

Nobili

Vetešník

Turicchia

et al. 2003

JARO

Self Cite

View full text Add to dashboard Cite

show abstract

“…Dallos 1992). Experimental results are available that studied the micromechanics of the organ of Corti in excised cochlear preparations, including guinea pig temporal bone preparations, sections of the guinea pig, gerbil cochlea, and the gerbil hemicochlea (Chan and Hudspeth 2005;Edge et al 1998;Fridberger et al 2002a, b;Fridberger and de Monvel 2003;Hu et al 1995Hu et al , 1999Jacob et al 2011;Jia et al 2007;Karavitaki and Mountain 2007a, b;Karavitaki et al 1996;Mammano and Ashmore 1993;Morioka et al 1995;Nowotny and Gummer 2006;Reuter et al 1992;Dallos 2001, 2003;Richter et al 2002Richter et al , 2000von Tiedemann et al 2010). Results have been published using confocal microscopy or optical coherence tomography (OCT) to study micromechanics of the cochlea in vivo (Chen et al 2007(Chen et al , 2011Choudhury et al 2006;Gao et al 2011Gao et al , 2013Masaki et al 2009;Zha et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Basilar Membrane and Tectorial Membrane Stiffness in the CBA/CaJ Mouse

Teudt

Richter

2014

JARO

View full text Add to dashboard Cite

The mouse has become an important animal model in understanding cochlear function. Structures, such as the tectorial membrane or hair cells, have been changed by gene manipulation, and the resulting effect on cochlear function has been studied. To contrast those findings, physical properties of the basilar membrane (BM) and tectorial membrane (TM) in mice without gene mutation are of great importance. Using the hemicochlea of CBA/CaJ mice, we have demonstrated that tectorial membrane (TM) and basilar membrane (BM) revealed a stiffness gradient along the cochlea. While a simple spring mass resonator predicts the change in the characteristic frequency of the BM, the spring mass model does not predict the frequency change along the TM. Plateau stiffness values of the TM were 0.6±0.5, 0.2± 0.1, and 0.09±0.09 N/m for the basal, middle, and upper turns, respectively. The BM plateau stiffness values were 3.7±2.2, 1.2±1.2, and 0.5±0.5 N/m for the basal, middle, and upper turns, respectively. Estimations of the TM Young's modulus (in kPa) revealed 24.3±25.2 for the basal turns, 5.1±4.5 for the middle turns, and 1.9±1.6 for the apical turns. Young's modulus determined at the BM pectinate zone was 76.8±72, 23.9±30.6, and 9.4±6.2 kPa for the basal, middle, and apical turns, respectively. The reported stiffness values of the CBA/CaJ mouse TM and BM provide basic data for the physical properties of its organ of Corti.

show abstract

“…However, the electrical stimuli were applied across the whole epithelium, thus polarizing many cells. Second, if only a single OHC were depolarized, its motion would be restricted by attachments to neighboring cells and by the stiffness of the reticular lamina (assuming that most of the force developed by OHC shortening went into deforming the reticular lamina rather the basilar membrane) (Mammano and Ashmore, 1993). These mechanical limitations could account for the smaller motion of adjacent cells in the same row (Fig.…”

Section: Depolarization-evoked Bundle Motion Occurs By Two Mechanismsmentioning

confidence: 99%

“…Electrical stimuli applied across the organ of Corti in isolated preparations have been shown to produce deformation of the cochlear partition (Mammano and Ashmore, 1993) and motion of the hair bundles of inner hair cells (Chan and Hudspeth, 2005).…”

Section: Introductionmentioning

confidence: 99%

Depolarization of Cochlear Outer Hair Cells Evokes Active Hair Bundle Motion by Two Mechanisms

et al. 2006

View full text Add to dashboard Cite

There is current debate about the origin of mechanical amplification whereby outer hair cells generate force to augment the sensitivity and frequency selectivity of the mammalian cochlea. To distinguish contributions to force production from the mechanotransducer (MET) channels and somatic motility, we have measured hair bundle motion during depolarization of individual outer hair cells in isolated rat cochleas. Depolarization evoked rapid positive bundle deflections that were reduced by perfusion with the MET channel blocker dihydrostreptomycin, with no effect on the nonlinear capacitance that is a manifestation of prestin-driven somatic motility. However, the movements were also diminished by Na salicylate and depended on the intracellular anion, properties implying involvement of the prestin motor. Furthermore, depolarization of one outer hair cell caused motion of neighboring hair bundles, indicating overall motion of the reticular lamina. Depolarization of solitary outer hair cells caused cell-length changes whose voltage-activation range depended on the intracellular anion but were insensitive to dihydrostreptomycin. These results imply that both the MET channels and the somatic motor participate in hair bundle motion evoked by depolarization. It is conceivable that the two processes can interact, a signal from the MET channels being capable of modulating the activity of the prestin motor.

show abstract

Reverse transduction measured in the isolated cochlea by laser Michelson interferometry

Cited by 180 publications

References 25 publications

Otoacoustic Emissions from Residual Oscillations of the Cochlear Basilar Membrane in a Human Ear Model

Otoacoustic Emissions from Residual Oscillations of the Cochlear Basilar Membrane in a Human Ear Model

Basilar Membrane and Tectorial Membrane Stiffness in the CBA/CaJ Mouse

Depolarization of Cochlear Outer Hair Cells Evokes Active Hair Bundle Motion by Two Mechanisms

Contact Info

Product

Resources

About