The effect of sectioning auditory centrifugal fibers on the cochlear microphonic and action potential in guinea pigs.

This investigation on 8 guniea pigs determined the immediate effect on the cochlear microphonic (CM) and action potential (AP) of ipsilateral sectoning of the autitory centrifugal fibers. An acoustic signal was used to evoke the CM and AP of one ear of guinea pig and the homolateral olivo-cochlear bundle and lateral lemniscus were then sectioned. Differences between pre- and post-section CM and AP were measured. The results demonstrated an increase in the CM and a decrease in the AP in all animals. Speculation with regard to the overall function of the auditory centrifugal system was offered.