Long-term study after perforation of the round window. Animal experiments using electric response audiometry.
The round-window membrane of the inner ear of the guinea pig was perforated with a platinum wire under ketamine-xylazine anaesthesia. The latency times of waves I and V (Jewett) increased to 0.6 ms at 100 dB click HL stimulus loudness. The interpeak latencies did not change (4.0-4.2 ms). At 60 dB CHL stimulus loudness, no responses were discernible. Closure of the membrane damage by adhesive fibrin tissue had no effect on the auditory nerve potentials or the brain-stem responses. Normal latency times of waves I-V were seen 7 days after perforation. There was no difference between the animals with repaired and unrepaired membrane damage. We observed spontaneous healing of the round-window membrane 7 days after perforation, and a normal organ of Corti.
D000161:Acoustic Stimulation; D000200:Action Potentials; D000818:Animals; D001300:Audiometry, Evoked Response / Q000379:methods*; D001933:Brain Stem / Q000502:physiology; D003051:Cochlea / Q000293:injuries*; D004338:Drug Combinations / Q000627:therapeutic use; D005176:Factor XIII / Q000627:therapeutic use; D015718:Fibrin Tissue Adhesive; D005340:Fibrinogen / Q000627:therapeutic use; D006168:Guinea Pigs; D011930:Reaction Time / Q000502:physiology; D012405:Round Window, Ear / Q000293:injuries* / Q000503:physiopathology; D013917:Thrombin / Q000627:therapeutic use; D013997:Time Factors; D014014:Tissue Adhesives / Q000627:therapeutic use; D000159:Vestibulocochlear Nerve / Q000502:physiology; D014950:Wounds, Penetrating / Q000503:physiopathology* / Q000628:therapy
D004338:Drug Combinations; D015718:Fibrin Tissue Adhesive; D014014:Tissue Adhesives; D005340:Fibrinogen; D005176:Factor XIII; D013917:Thrombin