The effect of unilateral surgical destruction of the cochlea on auditory sensitivity in the chinchilla

Abstract

Since the monaural chinchilla has proven to be an excellent subject for research in audition, the present study sought to assess possible changes in the audibility curve resulting from surgically rendering the chinchilla monaural. Nine chinchillas were trained to respond to six pure tones by the method of instrumental avoidance conditioning, after which threshold testing was conducted using a modified method of limits. After establishing the audibility curve of the binaural chinchillas, sterile surgery was performed to destroy the left cochlea of each animal. When recovery from surgery was complete, the animals were retrained and retested. Auditory sensitivity for tones spaced at octave steps from .25 to 8.0 kHz was found to decrease by a factor of 5 dB on the average 'as a result of the surgical procedure (range = 2.6-8.06 dB).

Ketamine-acepromazine as an anaesthetic agent for chinchillas (Chinchilla laniger)

“…In recent years the chinchilla has become an excellent subject for research in audition (Miller, ]970; Eddy et al, 1974;Eddy, Morgan & Carney, 1975;Bennett, Morgan, Murphy & Eddy, 1978). However, few effective anaesthetics for surgical procedures have been reported.…”

Temporary threshold shifts in auditory sensitivity produced by the combined effects of noise and sodium salicylate

“…Thirteen adult chinchillas, rendered monaural by surgical de-95 struction of the left cochlea (see Bennett, Morgan, Murphy, & Eddy , 1978) were selected for this study . All of them were in excellent health and easy to handle.…”

“…The behavior training equipment and threshold testing procedures used in this experiment were described in our previous paper (Bennett et al, 1978). Pretreatment audiograms were obtained prior to the noise experiment (Group A), the salicylate experiment (Group B), and the noise-salicylate experiment (Group A).…”