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Semin Hear 1999; 20(1): 3-12
DOI: 10.1055/s-0028-1089908
Copyright © 1999 by Thieme Medical Publishers, Inc.

The Effect of Perilymphatic Tetrodotoxin on Peripheral Auditory System Function

H. Alexander Arts* , Susan J. Norton† , Edwin W. Rubel†
  • *Department of Otolaryngology – Head & Neck Surgery, University of Michigan School of Medicine, Ann Arbor, Michigan.
  • †Dept. of Otolaryngology – Head & Neck Surgery, University of Washington School of Medicine, Seattle, Washington
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Publication Date:
14 October 2008 (online)

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Abstract

Several studies have indicated that efferent activity influences otoacoustic emissions. The present studies have been designed to evaluate the influence of auditory nerve activity on otoacoustic emissions. The distortion product otoacoustic emission (2f1 - f2 ) (DPOAE) was studied in Mongolian gerbils before and after placement of tetrodotoxin (TTX) within the round window niche. The release compound used was ethylene vinyl-acetate copolymer resin (Elvax®). Elvax alone had no effect on the DPOAE, auditory brainstem response (ABR), or cochlear microphonic (CM). Elvax with TTX resulted in preservation of the DPOAE and CM, but elimination of the ABR. This study demonstrates that the generation of action potentials in efferent and afferent axons of the auditory nerve is not required for the maintenance of DPOAEs. Further, in the anesthetized gerbil, complete blockade of action potentials in the auditory nerve has no systemic influence on DPOAE magnitude.

Keywords:

Otoacoustic emissions - tetrodotoxin - hair cell