Structure of the Upper and Lower Surfaces of Human Corpus Callosum

Abstract

The corpus callosum in the interval between the cerebral hemispheres is a plate of white matter, uneven in thickness, in which two surfaces are distinguished - the upper and lower ones, bent according to its lateral profile. The objective of the study was to study the individual variability of location of the lateral and medial longitudinal strips on the upper surface of the corpus callosum, as well as structural features of its lower surface. The material was the brain of men and women (10 specimens each) of the second period of adulthood, who died for the causes not related to the pathology of the central nervous system. After two weeks of fixation in a 10% formalin solution, the brain was prepared by separating the cerebral hemispheres and other parts of the brain from the corpus callosum, resulting in exposure of its upper and lower surface, which was photographed using a digital camera. As evidenced by the obtained data, the width of the trunk of the corpus callosum in men varies from 9 to 16 mm, whereas in women the difference between the minimum (11.0 mm) and the maximum (20.0 mm) values is greater than in men, when in fact there is only small difference of the arithmetic mean value. Thus, we offer to consider the lateral longitudinal strips to be the boundaries of the corpus callosum hemispherical part and the distance between them determines the width of this formation, which in average is 13.0 ± 2.5 mm in men and 14.4 ± 2.7 mm in women. In the meantime, the nature of the individual variability of the width of the corpus callosum trunk in women is more diverse than in men.