[Digital morphometric study of the extrasulcal surface of the cingulate gyrus in man]

The frequency of different morphological types and extrasulcal (visible) surface area of the cingulate gyrus, were measured and analysed in order to obtain more precise data about morphology, right/left and sex differences in the human brain.

The study included 42 brains (84 hemispheres) from persons of both sexes and of different age (26 males, 16 females, 20-65 years old), without neuropathological changes. After fixation in 10% formaline (3-4 weeks) and removal of meninges the brains were photographed under standard conditions by digital camera. Following determination of morphological type, regions of interest of cingulate gyrus were determined in stereotactic system system of coordinates and the extrasulcal surface was measured by digital AutoCAD planimetry.

Three basic morphological types of cingulate gyrus were found: the continuous type (34.5%), segmented type (35.7%) and double paralel type (29.8%). There was no statistically significant difference in the frequency of morphological types related to the side (right/left) or sex (p 0.05). The area of extrasulcal cortex of cingulate gyrus was statistically significantly (p < 0.05) larger on the left hemispheres (for 1.13 cm) than on the right (left: 14.58 cm; right: 13.45 cnm. 7he extrasulcal surface of the left cingulate gyrus was significantly larger (p 0 .05) in males (males 15.9 cm; females - 13.6 cm), while for the right cingulate gyrus this difference was not significant.

Morphometry indicated sex and right/left differences of extrasulcal surface area of the human cingulate gyrus. However, the morphological analysis itself did not indicate corresponding differences, suggesting complexity of the problem of sex dimorphism and of right/left asymmetries in the domain of limbic cortex.