SALICYLATE-INDUCED CHANGES IN CAT AUDITORY-NERVE ACTIVITY

The purpose of this study was to measure, in the cat, spontaneous audi tory nerve (AN) activity before and after injection with sodium salicy late. Ten cats were anesthetized, and the AN and round window (RW) wer e surgically exposed. Electrodes were applied to allow recording from three channels, including bipolar electrodes and monopolar electrodes located directly on the auditory nerve, in addition to an RW electrode . Spectral averaging of the spontaneous activity was performed before and during salicylate treatment. An increase in spectral activity near 200 Hz was noted in all cats by 3 hours after salicylate injection. T his activity was present in bipolar, monopolar, and RW records, and wa s temporarily diminished or eliminated by injection of lidocaine. No s uch spectral changes were found in saline-injected control animals. Th ese results show promise of developing a noninvasive, objective, quant itative measure of tinnitus for studies in animals and in man.