Applying Neurotrophins to the Round Window Rescues Auditory Function and Reduces Inner Hair Cell Synaptopathy After Noise-induced Hearing Loss
David J Sly, Luke Campbell, Aaron Uschakov, Saieda Tasfia Saief, Matthew Lam, Stephen J O'Leary
OTOLOGY & NEUROTOLOGY | LIPPINCOTT WILLIAMS & WILKINS | Published : 2016
HYPOTHESIS: Applying neurotrophins to the round window immediately after a single noise exposure will prevent noise-induced hidden hearing loss. BACKGROUND: Loud noise can eliminate neural connections between inner hair cells and their afferent neurons (thereby diminishing sound perception) without causing a detectable change on audiogram. This phenomenon is termed hidden hearing loss. METHODS: Guinea pigs were exposed for 2 hours to 4 to 8 kHz noise at either 95 or 105 dB SPL. Immediately afterward a 4 μl bolus of neurotrophins (brain-derived neurotrophic factor 1 μg/μl, and neurotrophin-3 1 μg/μl) was delivered to the round window of one ear, and saline to the other. Auditory brainstem res..View full abstract
The authors thank Prudence Nielsen for histology support, Joy Parker for animal support, Damien Myers for imaging support, and Alice Guidera and Jessica Choong for help developing counting protocols. Both David Sly and Luke Campbell received funding from the Garnett Passe and Rodney Williams Memorial Foundation. Stephen O'Leary is a Practitioner Fellow of the National Medical Research Council (Australia).