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Biomedical subjects

L I Malofeeva

Publications and source records attributed to L I Malofeeva.

18 recordsLinked to original sources
PubMed2005

No postnatal doubling of number of neurons in human Broca's areas (Brodmann areas 44 and 45)? A stereological study.

In this study we explored whether a postnatal doubling of the total number of neurons occurs in the human Brodmann areas 44 and 45 (Broca's area). We describe the most recent error prediction formulae and their application for the modern stereological estimators for volume and number of neurons. We estimated the number of neurons in 3D optical disector probes systematically random sampled throughout the entire Brodmann areas (BA) 44 and 45 in developing and young adult cases. In the relatively small number of male and female cases studied no substantial postnatal increase in total number of neurons occurred in areas 44 and 45; the volume of these areas reached adult values around 7 years. In addition, we did find indications that a shift from a right-over-left to a left-over-right asymmetry may occur in the volume of BA 45 during postnatal development. No major asymmetry in total number of neurons in BA 44 and 45 was detected.

Adult↗
PubMed2004

Variability in the structure of field 39 of the lower parietal area of the cortex in the left and right hemispheres of adult human brains.

The cytoarchitectonics of field 39 of the lower parietal area of the cortex in the left and right hemispheres were studied in normal individuals and professionally gifted world-famous people. Series of frontal sections were studied, stained by the Nissl cresyl violet method. The profile area of neurons was measured in layers III and V and the distribution of neurons in terms of this property was analyzed. Gifted people showed a significantly greater level of individual variability in the measures recorded here, especially in the right hemisphere, with larger proportions of very small and very large neurons.

Adult↗
PubMed2003

[Variability of the structure of area 39 of inferior parietal cortex in the left and right hemispheres of adult human brain].

The cytoarchitecture of area 39 of inferior parietal cortex region in the left and right cerebral hemispheres was studied in usual individuals and in professionally gifted world-famed people. The series of frontal sections, stained using Nissl cresyl violet method, were examined. The profile areas of neurons in cortical layers III and V were measured and their distributions were analyzed. In the group of gifted people, individual variability of the characteristics studied was found to be significantly increased, especially in the right cerebral hemisphere, while the relative content of both very small and very large neurons was elevated.

Adult↗
PubMed2002

[Peculiarities of the structure of the speech-motor cortex of the brain frontal lobe in a deaf-mute child].

The aim of present investigation was the study of the cytoarchitecture of the motor-speech areas 44 and 45 of the brain cortex of a 4-year-old deaf-mute child. We have also compared cytoarchitecture of the motor-speech zone of the brain cortex in a deaf-mute child with the same brain region in a normal child of a similar age. Series of 20 mm-thick frontal sections stained with cresyl violet were studied using morphometric methods. Our data indicate the significant anomalies of both the brain gross structure and cytoarchitecture of the motor-speech zone of the brain cortex in a deaf-mute child. Considerable decrease in the values of neuronal profile area in layers III3 and V and in satellite gliocyte density was observed while the neuro-glial ratios were changed. Our results certify that development of child's brain is disturbed in conditions of speech dysfunction and auditory deficiency.

Brain↗
PubMed2000

[The developmental characteristics of speech-motor areas 44 and 45 in the left and right hemispheres of the human brain in early postnatal development].

Cytoarchitecture of speech areas 44 and 45 of human brain was studied on frontal series of sections of brain of a newborn, 6 months, 1 year and 2 years old child. Sections were stained with cresyl violet after Nissl. Density of neurons and gliocytes location as well as fraction of satellite gliocytes and surrounded by the latter, glia index were determined by quantitative methods. General principles of cortical areas 44 and 45 were distinguished as well as peculiarities of their formation if left and right hemispheres of human brain in postnatal ontogenesis. Heterochronia of postnatal development of areas 44 and 45 was demonstrated. A hypothesis on different activity of right and left hemispheres speech areas in different periods of speech development of the child was discussed.

Aging↗
PubMed1998

[Structural asymmetry of cortical areas 44 and 45 in brain of newborns].

Peculiarities of topography, structure and length of sulci and gyri in left and right hemisphere frontal areas were studied in newborns. Peculiarities of cytoarchitectonics of speech areas 44 and 45 were described in left and right hemisphere of neonatal brain. Differences in the extent of neuron radial orientation and thickness of the cortex especially of layer III were defined. Great variability in square of areas 44 and 45 in left and right hemisphere of neonatal brain was established. A hypothesis on formation of structural asymmetry of the Broca center and its areas 44 and 45 by the moment of birth and heterochronia of these fields development in ontogenesis is discussed.

Brain Mapping↗
PubMed1994

[The problem of the individual variability of the human brain].

Series of frontal sections, 20 microns thick, were used to study the individual cytoglio-architectonic features of fields 8.8, 39, 40, 41, 43, 44, 45, 47 of the caudate nucleus, dorsomedial nucleus of the thalamus, Meynert's nucleus in 12 persons aged 29 to 89 years. The profile fields of neurons, their density and the density of gliocytes, including perineuronal ones were measured by computed morphometry, the cellular composition was determined from size of neurons, as well as the neuroglial and neuroperineuronal indices were defined. In 6 cases (distinguished, gifted persons), all the formations under study showed structural signs (abundant satellitosis, predominant large neurons, etc.) suggesting that there is a high functioning of nerve cells whose quantitative parameters are greater than those in other cases.

Adult↗
PubMed1985

[Various patterns in structural changes in the cortex and subcortical structures of the human brain during the aging process].

The authors examined the structural organization of cortical and subcortical formations (fields 4, 6, 8, 44, 47, 39, the head of the caudate nucleus and thalamic nuclei) of the right and left hemispheres of the brain of 6 mentally normal subjects aged 30 to 90 years. In sections 20 millimicron thick and stained by Nissl's method the authors measured the density of neurons in subcortical nuclei, in layers III and V of the cortical fields, as well as the number of neurons containing lipofuscin. The identified characteristics indicate heterochronicity of the process of ageing in different portions of the brain: motor and, particularly, cortical structures are involved in this process earlier and more intensively than others.

Adult↗
PubMed1983

[Morphologic criteria of the structural asymmetry of the cortical and subcortical structures of the human brain].

Using a cytoarchitectonic and quantitative methods, the authors investigated the structural organization of Fields 4, 6, 8, 39, 40, 43, 46, 47, caudate and dorsomedial nuclei of the tuber cinereum in the right and the left cerebral hemispheres in a grown-up right-handed man. With the help of electron computers definite parameters of neurons in the cortex (layers III and V) and in the subcortical nuclei were determined. The material obtained was statistically processed. Morphological criteria of the structural organization of the above-listed formations were identified. These included indicators of the total volumetric fraction of neurons and glia, profile fields of neurons, and the neuronal composition. Structural asymmetry was revealed, with the left hemisphere being dominant in the logomotor and motor fields. There were no signs of structural asymmetry in either the frontal and parietal fields or in the subcortical formations. The interpretation of the results obtained is attempted.

Adult↗
PubMed1982

[Morphological criteria of the individual variability of the human brain].

Structural organization of the layers III and V in the cortical fields (speech area, motoring, frontal inferior parietal) of the cerebral hemispheres and the nucleus caudatus have been quantitatively studied in 4 human beings. By means of a computer, area of profile fields of neurons, total volume of all the neurons and glyocytes in the histological section (total volumetric fraction of the neurons and glia) have been calculated, as well as percentage of the neurons having various size. The material is statistically treated. Certain morphological criteria of individual peculiarities have been established in the structural organization of the cortical and subcortical formations in the human brain. Individual variants in the value of the total volumetric fraction of the neurons and glia have been revealed, as well as peculiarities in composition percent of neuronal cells in the layers III and V. Differences in the area indices of the profile fields in separate persons and in various structures have been ascertained.

Adult↗
PubMed1977

[Structural organization of the cetacean neocortex].

As a result of investigation on architectonics of structural organization of the brain neocortex in dolphin, frontal, parietal, temporal and occipital regions, as well as certain fields were distinguished. Monotonous character and incomplete stratification of the neocortical lamina, lack of clear border line and similarity with interstitial formations demonstrate symbolic meaning of the word neocortex as it is applied to the cetacean brain. Therefore, the term preneocortex is suggested for the dolphin brain.

Animals↗
PubMed1975

[The sterologic method of determining the surface area of the mammalian neocortex].

A method for calculation of the square surface area of the cerebral cortex is proposed which represents a combination of the method of averaged reconstruction after a continuous series of histological sections and the stereological method of determination of the length of any curve disposed on the surface. A comparative analysis of the proposed method with curvometrical and stereological (after Hennig's formula) method used earlier for this purpose is made taking as an example the calculation of the neocortex square surface area of some mammals. The results of calculation of the surface by the proposed method were found to coincide with curvometrical data within the range of 5% while the data obtained by stereological method of determination of the absolute square surface area differ from curvometrical data by more than 22%. The proposed method is very convenient and allows considerable acceleration in obtaining results.

Animals↗
PubMedDate not supplied

[Basic principles of structural asymmetry of cortex formations in the human brain].

Studying the cytoarchitectonical asymmetry of human brain cortex requires using the new approaches and modern quantitative methods. One of the promising ways is analyzing relation between the macroscopic and neuronal structure of the brain. The present article contains original data of histological and morphological studies. The authors develop the concept of different degree of expression of asymmetry in the cortex formations of left and right hemispheres. The data on the principal differences of topography and types of structure of fissure and gyrus in different brain hemispheres are presented. Results of the analysis carried out enable one to show the basic criteria of peculiarities of cytoarchitecture of human brain cortex in the left and right hemispheres.

Cell Count↗