Fig. 2.

(A–C) Gait analysis of otoconia mutant mice. Compared with wt mice (n=18, P16), Oc90 null mice (n=16, P16) have wider stances of the hind limbs (hind limb base or HB), shorter strides of all limbs, a smaller LRA and a larger OL. Compared with age-matched C57 mice (n=18, P20), the gaits of homozygous Otop1^tlt mice (n=6, P20) show significant differences in all measurements including wider stances and shorter strides of all limbs, a smaller LRA and a larger OL. In comparison, the gaits of homozygous Nox3^het mice (n=6, P20) have similar strides and LRA compared with those of C57 mice, but show wider stances of all limbs and a larger OL. FB and HB, forelimb and hind limb base. LFS and RFS, left and right forelimb strides. LHS and RHS, left and right hind limb strides. * P<0.05; ** P<0.01; *** P<0.001. (D, E) Poor balance and coordination of Oc90 null mice on the accelerating rod as compared with other otoconia mutants (2–6 months old). The latencies on the rotorod are compared in Table 3. (D) Oc90 wt (n=7) and null (n=9) mice. (E) C57 (n=7), homozygous Otop1^tlt (n=8) and Nox3^het (n=8) mice. Oc90 null mice stayed on for a significantly shorter time than wt mice, Otop1^tlt mice even shorter and Nox3^het the shortest. All mice stayed longer with the progressing of each trial, with Oc90 wt and C57 improved the most (P<0.001). The rate and extent of learned adaptation for each strain of mice ranked the same order as their initial balance ability, with Nox3^het mice showing only limited improvement (E).