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E J Kletsky

Publications and source records attributed to E J Kletsky.

5 recordsLinked to original sources
PubMed1980

CM tuning can be compatible with sharply tuned receptor potentials.

There is convincing evidence that cochlear microphonics (CM) arise primarily from outer hair cells and have a frequency distribution that is much broader than that measured in inner hair cells by Russel and Sellick [6,7]. The broad tuning results from the fact that CM generated at each location decays exponentially along the cochlear duct. This implies that the sources of CM (the outer hair cells) must be more sharply tuned than the CM itself. We modeled approximately the tuning of outer hairs on the assumption that it is proportional to the shear motion between the tectorial membrane and the reticular lamina. At each frequency the spatial distribution of CM is computed by convolving the shear distribution with an exponential decay function. The frequency dependence of CM at a given location can then be found by making a cut through a family of such frequency curves. The resulting CM tuning is much flatter than that of the modeled outer hair-cell receptor potentials and roughly parallels basilar-membrane tuning below the best frequency. Above the best frequency, the theoretical curves show a frequency-dependent plateau similar to that found in physiological CM measurements.

Basilar Membrane↗
PubMed1979

Tectorial membrane: a possible effect on frequency analysis in the cochlea.

Mathematical analysis and computer and network simulations of the cochlea show that, given appropriate values of specific physical constants, radial shear motion between the tectorial membrane and the reticular lamina may provide the sharpening of frequency analysis observed in cochlear nerve fibers in comparison with the mechanical amplitude distribution on the basilar membrane. According to the analysis, the sharpening occurs through an interaction of the longitudinal mechanical propagation constant of the tectorial membrane with the wavelength on the basilar membrane.

Basilar Membrane↗
PubMedDate not supplied

What basilar-membrane tuning says about cochlear micromechanics.

Experiments performed within the last 15 years on cochleas of live animals indicate that the cochlear sound analysis is much sharper than was expected from Békésy's experiments on postmortem preparations. The mechanism underlying the sharp analysis has not yet been ascertained experimentally. However, details of mechanical tuning curves defined by the amplitude of basilar-membrane vibration as a function of sound frequency ofr a constant amplitude of stapes displacement, together with structural and physical properties of he basilar and tectorial membranes and of the organ of Corti, strongly suggest a mechanism. The mechanism is assumed to result from a resonance of the tectorial membrane produced by interaction of the membrane's mass with its viscoelastic attachments to the organ of Corti and the spiral limbus. The resonance would produce a strong vibration of the tectorial membrane in the radial plane and enhance the shear motion between the membrane and the reticular lamina. Mechanical and computer models of the mechanism have allowed the authors to reproduce in detail the empirical basilar membrane as well as corresponding neural tuning curves and to account for associated cochlear nonlinearities.

Animals↗