The effects of total and partial callosal agenesis on the development of morphological brain asymmetries in the BALB/cCF XXXX .

@entity19 @entity6789 @entity75 @entity10371
The @entity6789 fails to develop in some @entity19 of the BALB/cCF strain. We report here a study on cerebral morphological asymmetry in males of this particular strain in order to test the hypothesis that the normal development of the @entity6789 is responsible for the establishment of brain asymmetries. In 46 animals the dorsal area and the weight of each hemisphere were measured. In order to identify the animals with @entity75 and check for size anomalies of the anterior commissure, the hemispheres were cut into sagittal sections and stained with @entity10371 . Measures of sagittal area of the anterior commissure did not support the hypothesis that this commissure is enlarged when the @entity6789 is reduced or absent. In normal animals, the mean difference between left and right dorsal cortical areas showed a significant directional asymmetry, the left being consistently greater than the right. A similar pattern was found for weight. In @entity19 with @entity75 there were no significant differences, either between the dorsal areas or between the weights of the hemispheres. However, data on the absolute values of the hemispheric differences indicated the presence of a nondirectional asymmetry not only in normal animals, but also in @entity19 with @entity75 . Therefore, our data suggest that the ontogenesis of the @entity6789 plays a role in directing the development of cerebral asymmetries.
