Paw preference in mice: a reappraisal.

Paw preference in three strains (BALB/cA, C57BL/6J, Jcl:ICR) of mice was measured using the method of R. L. Collins (RPE score). We found that a) the patterns of paw preference were not so distinct as in previous studies, b) however, among these three strains, there were some differences in their patterns; namely, slight laterality was found in the C57BL/6J strain (RPE score distribution flattened), although no laterality was found in BALB/cA or Jcl:ICR strain (RPE score distributions bell shaped). These findings differ from those of previous studies. In this study we also propose a simplified method for determining paw preference in mice.