Recovery of vestibular function following hair cell destruction by streptomycin.
Can the vestibular periphery of warm-blooded vertebrates recover functionally from severe sensory hair cell loss? Recent findings in birds suggest a mechanism for recovery but in fact no direct functional evidence has been reported. We produced vestibular hair cell lesions using the ototoxic agent streptomycin sulfate (600 mg/kg/day, 8 days, chicks, Gallus domesticus). Compound action potentials of the vestibular nerve were used as a direct measure of peripheral vestibular function. Vestibular thresholds, neural activation latencies and amplitudes were documented. Eight days of drug treatment elevated thresholds significantly (P < 0.001) and eliminated all but remnants of vestibular activity. Virtually complete physiological recovery occurred in all animals studied over a period of 70 days following treatment. Thresholds recovered within two weeks of drug treatment whereas the return of response morphologies including activation latencies and amplitudes required an additional 6-8 weeks.
Jones
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TA
Neurophysiology Laboratory, University of Nebraska Medical Center, College of Dentistry, Lincoln 68583-0740.
Nelson
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D000200:Action Potentials; D000818:Animals; D002645:Chickens; D004558:Electric Stimulation; D006198:Hair Cells, Auditory / Q000187:drug effects*; D013307:Streptomycin / Q000633:toxicity*; D014724:Vestibular Function Tests; D014722:Vestibule, Labyrinth / Q000187:drug effects / Q000502:physiology*
D013307:Streptomycin