Abstract
A simplified network model of the organ of Corti is analyzed with the assumption of parametric excitation via resistance changes in the hair cells' apical membrane. Pertinent network variables (intracellular resting and receptor potentials, cellular input resistance, extracellular potentials) depend on the ratios of basal (perilymphatic face) and apical (endolymphatic face) receptor cell resistances, denoted as shape factors. In the Appendix two methods are suggested for the computation of shape factors; both are based on the geometrical properties of hair cells. Various electrical quantities computed on the basis of shape factors are consistent with recent recordings from third turn inner and outer hair cells (Dallos et al. (1982): Science 218, 582-584). The model provides a plausible explanation for the experimentally observed discrepancy between inner and outer hair cell resting and receptor potentials. One potentially significant result of the analysis is the demonstration that since shape factors for outer hair cells are probably longitudinally graded, so must be all cellular electrical characteristics. Another interesting finding is that electrical interaction among neighboring hair cells is unlikely. A large-signal analysis of the circuit demonstrates that even in the absence of a non-linear input, the parametrically excited circuit itself generates pronounced distortion. The most significant consequence of this nonlinearity is a response asymmetry in which the depolarizing phase is greater than the hyperpolarizing one. Thus the circuit nonlinearity may, at least in part, account for the large positive d.c. response seen in both types of receptor cell (Dallos et al. (1982): Science 218, 582-584; Russell and Sellick (1978): J. Physiol. Lond. 284, 261-290).
Original language | English (US) |
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Pages (from-to) | 89-119 |
Number of pages | 31 |
Journal | Hearing research |
Volume | 12 |
Issue number | 1 |
DOIs | |
State | Published - Oct 1983 |
Funding
This work was supported by Grant NS 08635 from the NINCDS. Physiological data were obtained in cooperation with Drs. Ake Flock and Joseph Santos-Sacchi. The work benefited from the advice of Drs. Mead Killion, Evan Relkin and Jonathan Siegel. Portions of this material are included in: Hearing - Plysiologrcal Buses und Psychophysics, Editors: R. Klinke and R. Hartmann. Springer, Berlin. 1983 (P. Dallos, Cochlear electroanatomy: Influence on information processing).
Keywords
- cochlear hair cell
- cochlear model
- receptor potential
- sensory receptor
ASJC Scopus subject areas
- Sensory Systems