Mice and rats are among the most common animal model species in both basic and clinical neuroscience. Despite their ubiquity as model species, many clinically relevant brain-behaviour relationships in rodents are not well understood. In particular, data on hemispheric asymmetries, are conflicting as existing studies are often statistically underpowered due to small sample sizes. Paw preference is one of the most frequently investigated forms of hemispheric asymmetries on the behavioural level. Here, a team from Bochum used meta-analysis to statistically integrated findings on paw preferences in rats and mice. For both species, results indicate significant hemispheric asymmetries on the individual but not population level. In mice, 81% of animals showed a preference for either the left or the right paw, while 84% of rats show this preference. These results are particularly significant as they point out that paying attention to potential individual hemispheric differences is important in both basic and clinical neuroscience.
Manns M, Basbasse YE, Freund N, Ocklenburg S. Paw preferences in mice and rats: Meta-analysis. Neurosci Biobehav Rev. 2021 Aug;127:593-606.