[Variability of the sulci and gyri of the inferior parietal region of the human brain in ontogeny].

Individual variability in the form of the inferior parieto-occipital gyri has been studied in 130 hemispheres of fetuses, children and grown-up persons beginning from 4 months of the intrauterine life up to 55 years of age. Differences in the form of the gyri have been noted already in the prenatal period; after birth, the process on complicating their configuration is continuing. Despite variety in their form, it is possible to reveal some peculiar U-like, III-like and transitive variants. Taking into account correlative dependence existing between the cortical fields size and the size of corresponding gyri, an applied importance of their individual variability could be supposed.