[Age-related features of the microstructure of layer V of human frontal lobe cerebral cortex].

Age related peculiarities of the microstructure of areas 8, 10 and subarea 32/10 in layer V of human frontal cerebral cortex were studied in left hemispheres of 103 individuals from birth to 20 years of age using histological methods and computer morphometry. Profile area of pyramidal neurons, radial fiber and fiber bundle thickness, and the distance between bundles were measured. During postnatal development of layer V in frontal cerebral cortex the following stages were distinguished: from a birth till 1 year, from 1-2 years till 5-6 years, from 6-7 till 9 years, from 9-10 years till 16-18 years. In each stage, the complex of microstructural changes was detected that was caused by increasing complexity of a system of transthalamic and other frontal cortex connections with other cortical and subcortical formations.

[Structural transformations of cyto- and fibroarchitectonics of the human frontal cerebral cortex from a birth till 20 years].

Research consist in studing cyto-and fibroarchitectonics of the human cerebral cortex (8, 10, 32/10, 44 and 45 frontal areas). Informative parameters of ansemble postnatal features in cortical organizations for studying at cellular-population level is established. They have included dimensional parameters of neural groupings at layer III and a parity of specific neuronal and fibrous volumes. It is shown, that associative fields 44, 45, 10 in lateral frontal zones is the most long develop in ontogenesis. Especially important structural transformations to them carry staged character and are marked on the first year of a life, and also by 3, 6-7, 10 and 13-14 years.

Quantitative changes in the fibroarchitectonics of the human cortex from birth to the age of 12 years.

Brains from 74 children aged from birth to 12 years were used to study fibroarchitectonic characteristics in topographically and functional diverse cortical zones (the temporal-parietal-occipital subregion, occipital, precentral, postcentral, and frontal areas) of the cerebral cortex; children aged up to 12 months were studied on the basis of one-month age intervals. Studies were performed by computer analysis of optical images on frontal sections stained with Nissl cresyl violet and silver nitrate impregnation by the modified Peters method. Data on the rate of increase in the thickness of radial bundles of fibers, the distances between bundles, and the age dynamics of the ratios of the specific volumes of neurons and fibers in fields 3, 4p, 6op, 17, 19, 37ac, 44, and 32/10 were obtained. These measurements showed that age-related transformation of fibroarchitectonics in fields of the sensorimotor, somatosensory, occipital, temporal-parietal-occipital, and frontal areas occurred at different times and with different intensities; the most significant changes were seen in the first 2-3 years of life, with changes continuing at a less intense level to age 9-12 years.

[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.

[The modular organization of the granular layer of the human cerebellar cortex in postnatal ontogeny]. / Modul'naia organizatsiia zernistogo sloia kory mozzhechka cheloveka v postnatal'nom ontogeneze.

Age changes of microstructure of granular layer of the cortex of human cerebellum superior lobe (the area of clivus, posterior lateral regions of right and left tetrangular lobules) were studied in annual intervals from birth up to 20 yrs using computer analysis of optic images. Enlargement of the area of profile fields of cell groups in apical and basal regions of cerebellar folia from birth up to 14-15 yrs and differences between hemispheres in clasterization of granular layer were demonstrated. The data on age changes of cellular aggregations obtained allowed to formulate a hypothesis on autonomic local sensory networks of human cerebellar cortex associated with granular layer of cerebellar cortex that are considered as structural elements of module organization of the latter.

[Quantitative changes in piriform neurons of human cerebellar cortex from birth to 20 years]. / Kolichestvennye izmeneniia gruzhevidnykh neironov kory mozzhechka cheloveka ot rozhdeniia do 20 let.

Age changes of size parameters of piriform (Purkinje) neurons in visual cerebellar cortex (pyramid and lateral areas of right and left digastric lobes) were studied at monthly intervals (during the first postnatal year) and at annual intervals (since birth up to 20 yrs) using computer optic image analyzer. Postnatal development of piriform neurons from human cerebellar visual cortex was found to be periodic (cyclic); each morphological cycle is characterised by certain duration and a series of quantitative and qualitative changes.

[The structural transformations of the human cerebellar cortex from birth to 3 years]. / Strukturnye preobrazovaniia kory mozzhechka cheloveka ot rozhdeniia do 3 let.

Heterohronia of archi- and neocerebellar regions development was established by means of morphometric analysis of optical thickness, layers and parameters of Purkinje cells in monthly (first postnatal year) and yearly intervals in children from birth up to three years of age. Growth of the cortex diameter in flocculus was shown to occur earlier than in four-angular lobule and to be more intensive on the gyral apex than in deep regions of sulci. Growth of cortical thickness on the gyral apex is connected basically with the granular layer thickening, with the thickening of molecular and granular layers for the gyral lateral side and with that of molecular layer for the fundus of sulcus. Differences in the growth and differentiation speed were in Purkinje cells in topographically diverse cortical loci.

[Characteristics of the ensemble organization of the human cerebral cortex from birth to 20 years of age]. / Osobennosti ansamblevoi organizatsii kory bol'shovogo mozga cheloveka ot rozhdeniia do 20 let.

When studying frontal, somatosensory and visual areas of the human cerebral cortex from birth up to 20 years of age in year-to-year intervals, it has been stated that by birth in neocortex all components of the neuron-glio-vascular ensembles are presented. They are not connected in their composition. During the first year of life the size of all types of neurons increases, long-axonal basket neurons differentiate, fasciculi of radial fibers become thick. By 3 years of life in the ensembles the neurons are definitely grouped as clusters. Sizes of spindle-like and satellite neurons increase; they distribute their axonal collaterals vertically, horizontally and in frontal-posterior direction. By 5-6 years of age the horizontal connection system becomes more complex at the expense of longitudinal growth and ramification of lateral and basal dendrites of the pyramidal neurons. In the section transversal areas occupied with cell groups increase. By 9-10 years of age the pyramidal neurons reach their greatest size. By 12-14 years of age the fibrillar component of the cortex increases considerably, inter- and intraensemble horizontal connections become more complex, the system of local connections becomes more plastic owing to development of short-axonal basket-like neurons. By 16-18 years of age the ensemble cortical organization in its main parameters of architectonics reaches the level specific for mature persons.