Auditory-nerve activity in cats exposed to ototoxic drugs and high-intensity sounds.
The response characteristics of auditory-nerve fibers in normal cats are compared with those in cats exposed to kanamycin and high-intensity sounds. The pathophysiology is characterized by an elevation of the tuning-curve "tips," which is sometimes associated with hypersensitivity of the "tails". Plots of unit thresholds are correlated with patterns of sensory-cell losses in the cochlea. There can be significant shifts in unit threshold without significant loss of hair cells; however, significant hair cell loss is always accompanied by highly abnormal unit thresholds. The presence of inner hair cells seems to be essential for the long-term survival of spiral ganglion cells. An incidental observation is that in the "normal" animal there is almost always a prominent "notch" at 3-4 kHz in the plots of threshold at characteristic frequency, which may have been produced by environmental noise.
D000818:Animals; D002415:Cats; D003051:Cochlea / Q000473:pathology / Q000503:physiopathology*; D004594:Electrophysiology; D005724:Ganglia / Q000473:pathology; D006198:Hair Cells, Auditory / Q000473:pathology; D006317:Hearing Loss, Noise-Induced / Q000473:pathology / Q000503:physiopathology*; D007612:Kanamycin; D007759:Labyrinth Diseases / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology; D009412:Nerve Fibers / Q000473:pathology; D009925:Organ of Corti / Q000473:pathology; D013997:Time Factors; D000159:Vestibulocochlear Nerve / Q000473:pathology / Q000503:physiopathology*
D007612:Kanamycin