Abstract
The cochlear microphonic (CM) can be a useful analytical tool, but many investigators may not be fully familiar with its unique properties to interpret it accurately in mouse models of hearing. The purpose of this report is to develop a model for generation of the CM in wild-type (WT) and prestin knockout mice. Data and modeling results indicate that in the majority of cases, the CM is a passive response, and in the absence of outer hair cell (OHC) damage, mice lacking amplification are expected to generate WT levels of CM for inputs less than ∼30 kHz. Hence, this cochlear potential is not a useful metric to estimate changes in amplifier gain. This modeling analysis may explain much of the paradoxical data in the literature. For example, various manipulations, including the application of salicylate and activation of the crossed olivocochlear bundle, reduce the compound action potential but increase or do not change the CM. Based on this current evaluation, CM measurements are consistent with early descriptions where this AC cochlear potential is dominated by basal OHCs, when recorded at the round window.
Original language | English (US) |
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Pages (from-to) | 113-125 |
Number of pages | 13 |
Journal | JARO - Journal of the Association for Research in Otolaryngology |
Volume | 12 |
Issue number | 1 |
DOIs | |
State | Published - Feb 2011 |
Funding
We thank C.T. Anderson for collecting some of the data, M.A. Ruggero for providing the data upon which this work is based, and J.H. Siegel for software development. This work was supported by NIDCD Grant #DC00089.
Keywords
- cochlear amplifier
- compound action potential
- outer hair cells
- prestin knockout mice
- salicylate
ASJC Scopus subject areas
- Sensory Systems
- Otorhinolaryngology