Table 1.

Experimental time line.

CBA/J mice arrived at MUSC at the age of 10 weeks. Baseline ABRs were measured at the age of 11 weeks. At the age of 12 weeks, mice were exposed to noise. Two weeks after the noise exposure (14 weeks), mice were euthanized for surface preparations for hair cell counts (left ear) and ribbon counts (right ear) after post-noise ABR measurements. siRNA was delivered 72 h before the noise exposure. For immunohistochemistry, mice were euthanized 1 h or 24 h after the completion of noise exposure. MCU knockout mice and littermates were generated from breeders and ABRs were measured initially at the ages of 4, 5, 6, and 7 weeks to observe hearing function and some mice were euthanized for assessment of hair cell pathology using myosin-VIIa labeling and DAB staining as well as scanning electron microscopy. For noise-exposed mice, baseline ABRs were measured at the age of 4.5 weeks. Two weeks after the noise exposure (6.5 weeks), mice were euthanized for surface preparations of hair cell counts (left ear) and ribbon counts (right ear) after the post-noise ABR measurements. Some mice were euthanized 1 h or 24 h after the completion of noise exposure to evaluate ribbon synapses additional time points.