The effects of total and partial callosal agenesis on the development of paw preference performance in the BALB/cCF mouse.

The relation between callosal defects and paw preference was investigated in 85 male mice of the BALB/cCF strain. Paw preference was also studied in 30 male Swiss mice. Directional laterality and magnitude of laterality devoid of directionality were evaluated independently. The study of the magnitude of paw preference showed that male BALB/cCF mice were more strongly lateralized than Swiss mice. There was no difference between BALB/cCF mice with callosal defects (abnormal group) and normal BALB/cCF mice. The analysis of directional laterality indicated a population tendency for left-paw use in BALB/cCF as compared to Swiss mice. Furthermore, the percentage of left-pawed animals in the abnormal group (78%) was significantly different from chance level, as opposed to an absence of such differences in the normal BALB/cCF and in Swiss mice. It was concluded that developmental disturbance of the corpus callosum is related to the appearance of a directional populational asymmetry in paw preference.