Quantitative changes in fibro-architectonics of the human cerebral cortex from birth to 12 years of age [Kolichestvennye izmeneniia fibroarkhitektoniki kory bol'shogo mozga cheloveka ot rozhdeniia do 12 let.]

The peculiarities of fibroarchitectonics in topographically and functionally distinct cortical zones (including temporo-parieto-occipital subarea, occipital, pre-, postcentral, and frontal areas) were studied in the brain specimens of 74 children of different ages (from birth to 12 years) taken with yearly intervals, while those in the first year of life--with monthly intervals. Frontal sections stained with Nissl, Peters and Golgi methods were studied using computer analysis of optical images. The data were obtained on the increment rates of radial fiber fascicles' thickness, distances between fascicles and age dynamics of ratios of volume densities of neurons and fibers in areas 3, 4p, 6op, 17, 19, 37ac, 44 and 32/10. It was shown that age-related transformations of fibroarchitectonics in the areas of sensomotor, somatosensory, occipital, temporo-parieto-occipital and frontal cortex were heterochronic and took place with different intensity; most pronounced changes were found to occur during the first 2-3 years, while less intensive ones were observed up to the age of 9-12 years.