Related Experiment Video
Updated: Apr 30, 2026
The Mouse Round-window Approach for Ototoxic Agent Delivery: A Rapid and Reliable Technique for Inducing Cochlear Cell Degeneration
Published on: November 26, 2015
Development of an ototoxicity model in the adult CBA/CaJ mouse and determination of a golden window of corticosteroid
Vinay T Fernandes, Vincent Y W Lin1
1Department of Otolaryngolgy - Head and Neck Surgery, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Ave, Suite M1-102, Toronto, ON M4N 3M5, Canada. Vincent.Lin@sunnybrook.ca.
Objective:
To investigate the effect of timing of dexamethasone administration on auditory hair cell survival following an ototoxic insult with kanamycin and furosemide.
Study Design:
Controlled experimental study.
Setting:
Translational science experimental laboratory.
Methods:
5-6 week old CBA/CaJ mice, divided into 6 groups, were injected with kanamycin (1 mg/g SC) followed by furosemide (0.5 mg/g IP). Dexamethasone (0.1 mg/g IP) was injected at either 1 hour prior to insult, +1 hr, +6 hr, +12 hr, or +72 hr post insult. Temporal bones harvested on day 7 underwent Organ of Corti dissection. Immunohistochemical staining was performed using antibodies to myosin 7a, phalloidin, and TO-PRO.
Results:
Hair cell counts demonstrate a uniform ototoxicity model with total loss of outer hair cells (OHCs) and near-total loss of inner hair cells (IHCs). The group pre-treated with dexamethasone showed a statistically significant improvement in counts compared to controls (p = 0.004). Counts from the other experimental groups given dexamethasone after the insult were highly variable but demonstrated some apical and middle turn inner hair cell survival.
Conclusion:
Treatment of systemic dexamethasone prior to ototoxic insult attenuates hair cell loss in a reliable, novel, ototoxicity model using kanamycin and furosemide in CBA/CaJ mice. Dosing with dexamethasone following ototoxic insult shows promising yet variable response in hair cell survival.
