Evoked potential tuning curves and noise-induced threshold shift dynamics in chinchillas with inner hair cell deficient cochleas.
Rosenstein-KM; Ahroon-WA; Hamernik-RP
1998 Midwinter Meeting Assoc Res Otolaryngology, St. Petersburg Beach, Florida, 1998 Feb; :330
Carboplatin produces severe losses of inner hair cells (IHC) in the chinchilla while leaving the outer hair cells largely intact. This preparation has shown that despite up to 80% IHC losses, pure-tone thresholds, tuning curves and cubic distortion product otoacoustic emissions are essentially unaltered. With severe IHC lesions the response to asymptotic threshold shift (ATS) producing noise exposures and interrupted noise exposures that produce toughening effects are also unchanged relative to untreated control populations. Using a simultaneous masking paradigm and evoked potentials, tuning curves, pure-tone thresholds, input/output functions, and otoacoustic emissions were measured before and 30d following carboplatin treatment at 0.5,1, 2, 4, 8, and 11.3 kHz. In the drug-treated animals the above indices were not affected. The animals (N=5) were then exposed to an ATS-producing noise for 5d. Threshold shifts established ATS and after 30d the functional indices were again measured. For all indices the inner hair deficient cochleas responded to the noise in essentially the same way as normal animals.
Hearing-disorders; Noise-exposure; Hearing-loss; Noise-waves; Analytical-processes; Noise-induced-hearing-loss; Laboratory-animals; Animal-studies; Animals
1998 Midwinter Meeting of the Association for Research in Otolaryngology
Plattsburgh State University, New York