Fig. 4

OHCs of NPC1-KO mice remain susceptible to HPβCD. a DPOAE thresholds at f2 = 12 kHz of WT and NPC1-KO mice before and after four weekly injections of 4000 mg/kg HPβCD are plotted. Mice receiving single injections of high-dose (HD) HPβCD at 8000 mg/kg and their age-matched controls (Ctrl) are also shown. Each dot represents one mouse. Numbers and sexes are also indicated. Statistical significance is indicated by three asterisks (p < 0.001, two-tailed t-test). Variations in sensitivity to low-dose HPβCD in NPC1-KO (“After”) is not sex-dependent. b Cytocochleograms of WT and NPC1-KO mice that received four injections of 4000 mg/kg HPβCD or single injection of 8000 mg/kg HPβCD from (a) NPC1-KO mice receiving the low dose HPβCD injections showed large variations in OHC loss that correspond to the DPOAE thresholds. NPC1-KO mice treated with high dose HPβCD exhibit greater OHC loss than the low-dose groups