Generation of the Endocochlear Potential: A Biophysical Model
Imran H. Quraishi 1 and Robert M. Raphael 1*
1 Rice University
* To whom correspondence should be addressed. E-mail: rraphael{at}rice.edu.
Submitted on December 18, 2007
Revised on January 12, 2008
Accepted on 14 January 2008
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Abstract |
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The generation and maintenance of the endocochlear potential (EP) by the stria vascularis is essential for proper function of the cochlea. We present a mathematical model that captures the critical biophysical interactions between the distinct cellular layers that generate the EP. By describing the relationship between the K concentration in the intrastrial space and the intermediate cell transmembrane potential, we rationalize the presence of a large intermediate cell K conductance and predict that the intrastrial [K] is ~4 mM at steady state. The model also predicts that the stria vascularis is capable of buffering the EP against external perturbations in a manner modulated by changes in intrastrial [K], thus facilitating hearing sensitivity across the broad dynamic range of the auditory system.
Key Words:
cochlea, electrophysiology, epithelial transport, hearing, modeling, stria vascularis
