Shared and specific signatures of locomotor ataxia in mutant mice

Several spontaneous mouse mutants with deficits in motor coordination and associated cerebellar neuropathology have been described. Intriguingly, both visible gait alterations and neuroanatomical abnormalities differ across mutants. We recently quantified specific deficits in locomotor coordination in mildly ataxic Purkinje cell degeneration mice (pcd). Here, we analyze the locomotor behavior of severely ataxic reeler mutants. Despite clearly visible behavioral differences, we find that on average, affected features of locomotor coordination are generally similarly perturbed in the two mutants. Direct comparison of locomotor kinematics and linear discriminant analysis reveal that differences in the locomotor phenotypes of these two lines are largely attributable to additional hindlimb abnormalities and increased movement variability in reeler. These findings capture shared and specific signatures of gait ataxia across mutants and provide a quantitative foundation for mapping specific locomotor impairments onto distinct neuropathologies.