Doxycycline Administration.
Tg[E];Tg[R];Slc26a4Δ/+ DE17.5 mice and Tg[E];Tg[R];Slc26a4Δ/Δ DE17.5 mice were readministered doxycycline according to one of three paradigms: (1) no readministration of dox (DE17.5); (2) dox readministered at 1 month of age (DE17.5-RI1M: dox reinitiated at 1
month of age); and (3) dox readministered at postnatal day 6 (DE17.5-RIP6: dox reinitiated at P6). We also included a control group that received dox continuously from conception (IE0: dox initiated at E0). We measured click auditory brainstem response (ABR) thresholds at 1, 2 and 3 months of age, and then euthanized the mice for immunohistochemical (IHC) analysis. For DE17.5-RI1M mice at 1 month of age, we measured ABR thresholds before readministration of dox.