Secondary Degeneration of Auditory Neurons after Topical Aminoglycoside Administration in a Gerbil Model

Figure 2

Serial changes of the hearing threshold after drug administration. Hearing thresholds at multiple frequencies were measured at three different time points (1 week, 4 weeks, and 12 weeks) for kanamycin percutaneous (KP), kanamycin gelfoam (KG), and kanamycin RW injection (KI) groups. See Methods for more descriptions. In the KP group, hearing thresholds increased at high frequency regions (12, 16, and 32 kHz) at four weeks after drug administration and these increased thresholds remained until 12 weeks after drug administration. KG group showed a more severe hearing threshold change at all time points. KI group showed the worst hearing thresholds change at all tested frequencies and all test points ().