Figure 4.

Lack of correlation between percentage of lesion-induced corpus callosum reduction and scores for juvenile play behaviors (A-C), adult sociability (D, E), and self-grooming (F). Correlation analyses included lesioned mice only, using Pearson's r test. (A) Number bouts of nose-to-nose sniffing (r=0.304, NS); (B) Number of bouts in which one juvenile male mouse followed the other juvenile mouse (r=0.469, NS); (C) Number of bouts of push-crawl interactions (r=0.577, NS); (D) Time spent by the adult male subject mouse in the chamber containing the novel mouse (r=0.288, NS); (E) Time spent sniffing the novel mouse (r=0.216, NS); (F) Time spent self-grooming by the adult male subject mouse in the social approach apparatus (r=0.106, NS). Sham surgery mice (black triangles) were not included in the statistical analyses of r values, but are shown here for illustrative purposes only, as controls with zero for their lesion values. Sham B6: N=22 for juvenile play, N=19 for social approach. Corpus callosum-lesioned B6 (white triangles): N=31 for juvenile play, N=35 for social approach. Seven mice displayed complete 100% lesions, with no connections visible between the left and right cerebral cortex throughout the rostral-caudal dimension. Social scores and self-grooming remained within control ranges in mice with complete and partial lesions.