Quantitative Trait Loci Modulating Corpus Callosum Size in the Mouse Brain

The corpus callosum is the brain’s primary pathway for interhemispheric communication between the left and right hemispheres, and abnormal function and anatomy of the corpus callosum have been associated with a variety of disorders in humans and animals. In this study, we mapped quantitative trait loci (QTLs) modulating corpus callosum size in mice. By using mouse brain sections and stereological techniques, we estimated the midsagittal corpus callosum size in 191 BXD recombinant inbred mice and their parent strains (C57BL/6J and DBA/2J). Analysis showed midsagittal corpus callosum size to be a heritable trait (h = .42). We detected a suggestive QTL modulating corpus callosum size near the marker S10Gnf071.990 on chromosome 10 at approximately 73 Mb, in close proximity to a previously defined QTL modulating striatal volume. We also found correlations between corpus callosum size and other behavioral and anatomical phenotypes. Overall, our results implicate a genetic role in modulation of corpus callosum size.