Gender-Dependent Effect of Maternal Methyl-Enriched Diet on the Expression of Genetic Absence Epilepsy and Comorbid Depression in Adult Offspring of WAG/Rij Rats.

In the present study it has been shown for the first time that maternal methyl-enriched diet (choline, betaine, folic acid, vitamin B12, L-methionine, zinc) during perinatal period reduces the expression of genetic absence epilepsy and comorbid depression in adult offspring of WAG/Rij rats. This beneficial effect was more pronounced in males compared with females. It is assumed that epigenetic modifications induced by maternal methyl-enriched diet in the offspring at the early stages of ontogenesis might be a possible mechanism underlying the correction of genetically-based pathologic phenotype in WAG/Rij rats. Results suggest that methyl-enriched diet during perinatal period can be potentially used for mitigation or prevention epileptogenesis and depression-like comorbid disorders in people genetically predisposed to absence epilepsy.

[Application of brain electrical activity burst analysis method for detection of EEG characteristics in the early stage of Parkinson's disease]. / Primenenie metoda analiza vspleskoobraznoi élektricheskoi aktivnosti mozga dlia vyiavleniia osobennostei ÉÉG patsientov na rannei stadii bolezni Parkinsona.

AIM: To develop a mathematical method of analysis and visualization of EEG based on the ROC analysis of burst electrical activity in the cerebral cortex. MATERIAL AND METHODS: Using a new method of analysis of EEG burst activity, the frequency parameters of brain electrical activity have been investigated in patients in the first stage of Parkinson's disease (PD) defined by the Hoehn and Yahr scale. Patients were right-handed, with disease onset in either the right or the left side. The burst term is used in neurophysiology for the description of wave activity in EEG signals. Bursts are reflected in the local peaks of wavelet spectrograms, some of the parameters of which have been analyzed. Electrical activity of the left and right central cortex areas was investigated. The results were compared with those obtained from healthy volunteers. RESULTS: In PD patients, burst activity was changed in alpha- and beta bands. Compared to healthy volunteers, it was higher in alpha band 8-9 Hz and lower in upper alpha band 11-13 Hz and beta band 18-24 Hz. With regard to asymmetry of the brain in PD patients, there was the change in burst activity in both brain hemispheres. Diagrams of burst activity showed the difference between the patients with tremor onset in the left hand and tremor onset in the right hand. CONCLUSION: This suggests differences in brain electrical activity changes in patients with left-sided and right-sided disease onset. The initial results of the study demonstrate that the method of analysis and visualization based on the evaluation of certain parameters of EEG bursts is promising for the analysis of EEG features in PD patients.

Maternal care exerts disease-modifying effects on genetic absence epilepsy and comorbid depression.

WAG/Rij rats, a genetic animal model of absence epilepsy with comorbidity of depression, exhibit behavioral depression-like symptoms and spontaneous generalized spike-wave discharges (SWDs) in the EEG at the age of 6 to 8 months. The aim of the present study was to test the hypothesis that maternal care is an environmental factor which, along with genetic predisposition, may contribute to the expression of absence seizures and depression-like comorbidity later in life. To achieve this, a cross-fostering procedure was used. EEG and behavior in the forced swimming test were analyzed in WAG/Rij and Wistar offspring reared by their own mothers (non-cross-fostered), foster mothers of the same strain (in-fostered) or another strain (cross-fostered) at the age of 7 to 8 months. Maternal care and forced swimming test behavior were assessed in the dams. WAG/Rij mothers showed depression-like behavior and reduced maternal care irrespective of litter size and litter composition (own or foster pups) compared with Wistar dams. WAG/Rij offspring reared by Wistar dams with a high level of maternal care exhibited less and shorter SWDs and reduced depression-like comorbidity in adulthood compared with age-matched WAG/Rij offspring reared by their own or foster WAG/Rij mothers with a low level of maternal care. Moreover, rearing by Wistar mothers delayed the onset of absence epilepsy in WAG/Rij rats. Adoption by WAG/Rij dams did not change EEG and behavior in Wistar rats. Our study demonstrates that improvement of early care-giving environment can be used as a disease-modifying treatment to counteract epileptogenesis and behavioral comorbidities in genetic absence epilepsy.

Rearing by foster Wistar mother with high level of maternal care counteracts the development of genetic absence epilepsy and comorbid depression in WAG/Rij rats.

It has been shown for the first time that rearing by a foster Wistar mother with high level of maternal care (MC) counteracts the expression of genetic absence epilepsy (AE) and comorbid depression - reduces the number, duration and index of spike-wave discharges (SWDs) and immobility time in the forced swimming test, as well as exerts substantial effects on morphology and time-frequency dynamics of SWDs in WAG/Rij rats. It is supposed that increases in MC early in development might be used to counteract epileptogenesis and comorbid depression in people genetically predisposed to AE.

[FREQUENCY-TEMPORAL STRUCTURE OF HUMAN ELECTROENCEPHALOGRAM IN THE CONDITION OF ARTIFICIAL HYPOGRAVITY: DRY IMMERSION MODEL].

Frequency-temporal electroencephalogram (EEG) reactions to hypogravity were studied in 7 male subjects at the age of 20 to 27 years. The experiment was conducted using dry immersion (DI) as the best known method of simulating the space microgravity effects on the Earth. This hypogravity model reproduces hypokinesia, i.e. the weight-bearing and mechanic load removal, which is typical of microgravity. EEG was recorded by Neuroscan-2 (Compumedics) before the experiment (baseline data) and at the end of day 2 in DI. Comparative analysis of the EEG frequency-temporal structure was performed with the use of 2 techniques: Fourier transform and modified wavelet analysis. The Fourier transform elicited that after 2 days in DI the main shifts occurring to the EEG spectral composition are a decline in the alpha power and a slight though reliable growth of theta power. Similar frequency shifts were detected in the same records analyzed using the wavelet transform. According to wavelet analysis, during DI shifts in EEG frequency spectrum are accompanied by frequency desorganization of the EEG dominant rhythm and gross impairment of total stability of the electrical activity with time. Wavelet transform provides an opportunity to quantify changes in the frequency-temporal structure of the electrical activity of the brain. Quantitative evidence of frequency desorganization and temporal instability of EEG wavelet spectrograms may be the key to the understanding of mechanisms that drive functional disorders in the brain cortex in the conditions of hypogravity.

[Post-radiation effect on the interhemispheric asymmetry in EEG and thermography characteristics]. / Postradiatsionnye narusheniia mezhpolusharnoi asimmetrii élektroéntsefalograficheskikh i termograficheskikh kharakteristik vo vremia kognitivnoi deiatel'nosti.

Complex analysis of EEG and thermographic parameters carried out in 10 healthy subjects and 34 patients, Chernobyl clean-up participants revealed a correlation between EEG and brain temperature changes in the baseline state and during mental arithmetic. During cognitive activity the maximal increase in the average EEG coherence and temperature shifts in healthy subjects were observed in the left frontotemporal and right parietotemporal areas. In patients changes in both parameters under study were most pronounced, the interhemispheric relations were impaired. The visual analysis revealed "flat" and "hypersynchronous" EEG types in patients. The dominant pathologic activity in the betal range indicative of mediobasal and oral brainstem lesions was characteristic of the flat EEG. This type of activity was observed in 60% of patients. In these cases, a general decrease in EEG coherence and temperature was most pronounced in the left hemisphere. The hypersynchronou EEG type (40% patients) was characterized by paroxysmal activity in the theta and alpha ranges suggesting diencephalic brain lesions. In these cases, EEG coherence and temperature were more variable; changes in the right hemisphere were significant, be it increase or decrease. Our complex approach to investigation of brain activity in different aspects seems to be promising in estimation of the brain functional state both in healthy persons and patients in remote terms after exposure to radiation. The specific hemispheric temperature changes revealed in Chernobyl patients especially during cognitive activity can be the sequels of postradiation disorders of vascular neuro-circulation. The EEG findings suggest subcortical disorders at different levels (diencephalic or brainstem) and functional failure of the right or left hemispheres in remote terms after exposure to radiation.

[Peculiarities of growth and morphogenesis of syphoneal alga vaucheria sessilis in microgravity]. / Osobennosti rosta i morfogeneza sifoneal'noi vodorosli vaucheria sessilis v usloviiakh mikrogravitatsii.

The space experiment was aimed at studying the dependence on the gravity of intracellular processes in an autotrophic organism deprived of pronounced gravitropisms and gravitaxis. The experiment demonstrated an immediate gravitational effect on intercellular processes involving the syphoneal alga Vausheira sessilis cytoskeleton. In the absence of the force of gravity algal growth and morphogenesis are inhibited more significantly than under the condition of the Earth's gravity.

The position of nuclei and the role of cytoskeleton in graviresponse of siphonaceous algae Vaucheria sessilis.

Gravity has always been present during evolution. Through the process of natural selection, contemporary organisms could show evidence of having turned gravity to their advantage as an adjunct to development. In recent time great success has been achieved in description and analysis of gravitaxis mechanism of algae Chara (Sievers et. al., 1991) and Euglena (Hader et. al., l990). The aim of present investigation was the demonstration of gravity-dependent growth and development of algae without distinct gravitaxis and gravitisensor organelles, such as statoliths and amyloplasts.

[Patterns in the growth and functioning of single-cell organisms under conditions of altered gravitational force]. / Zakonomernosti rosta i funktsionirovaniia odnokletochnykh organizmov v usloviiakh izmenennoi sily tiazhesti.

The results of studies over many years on various types of unicellular free-swimming organisms in conditions of altered gravity (hyper-, hypo-, and microgravity ranging from 10(-5) to 5 g) were reviewed. Laws governing their growth and functioning under these conditions were established. In general, gravisensing of unicellular free-swimming organisms depends on their metabolic activity and mobility, on the one hand, and on the environmental conditions of the population, on the other. A working hypothesis on the priority of ecophysiological properties (environment, metabolic activity, and mobility) over morphological properties (mass, dimensions, and shape) in receiving and processing of gravity stimuli at the cellular level has been formulated.

Peculiarities [correction of Peculiarites] of the graviperception and graviresponses [correction of graviresponces] in some unicellular eukaryotic organisms.

NASA: The growth and ultrastructure of Vaucheria sessilis, a siphonaceous alga, were studied during simulated weightlessness using a clinostat and during hypergravity on a centrifuge. Observations, including abnormalities in sporulation and changes in the distribution of nuclei, are presented and discussed.^ieng

[Effects of altered gravity on the culture of unicellular eucaryotic organisms, Bursaria truncatella (Ciliophora)]. / Vliianie izmenennoi sily tiazhesti na kul'turu odnokletochnykh éukarioticheskikh organizmov Bursaria truncatella (Ciliophora).

The paper reports the results of experiments with centrifugation and clinostating. Growth rate, cellular division and several morphofunctional characteristics of unicellular organisms of infusoria Bursaria truncatella in culture were studied under normal (1 g), elevated (hypergravity at 2 and 5 g), and compensated gravity. The data point to certain changes in the functional activity and morphology of cells consequent to long-time cultivation under these conditions. The observed regularities in the dynamics of B.truncatella growth and shifts in its physiology and morphology due to hypergravity or compensated gravity support our earlier proposed working hypothesis about the dominance of functional activity over morphological properties in sensitivity of unicellular organisms to perception and realization of the gravitational stimulus.

[Biomechanical aspects of the process of formation of food vacuoles in the infusoria Bursaria truncatella under changed gravity]. / Biomekhanicheskie aspekty protsessa obrazovaniia pishchevykh vakuolei u infuzorii Bursaria truncatella v usloviiakh izmenennoi sily tiazhesti.

Results from clinostatic and centrifugal laboratory experiments in which there has been evaluated an activity of digestive process in infusoria Bursaria truncatella by the content of vacuole numbers and its change in the cell under changed gravity are presented. It is indicated that the extended clinostatic exposure of infusoria stimulates their digestive activity and an increased gravity (centrifugation 2 g, 5 g) inhibits this process. In these examinations, an effort was made to explain the obtained results started from the propositions of cell biomechanics and bioenergetics. The mechanisms of gravity influence on this process have been proposed.

[Cell growth and motility in culture (in vitro) under microgravity conditions. The Fibroblast Experiment]. / Rost i podvizhnost' kletok v kul'ture (in vitro) v usloviiakh mikrogravitatsii. Eksperiment "Fibroblast".

The experiment "Fibroblast" was performed in 1992 on biosatellite "Cosmos-2229" in onboard device "Biobox" designed by the order of European Space Agency. The main objective was elucidation of the mechanisms responsible for the effect of space flight factors, mostly microgravity, on cell culture. We studied time-related changes in growth, motility and some morphological characteristics of the cells in monolayer cultures on a solid substrate and in three-dimensional cultures supported by sponge gels. Studies were carried out on connective tissue cells isolated from the mouse embryos. Comparative after-flight analysis of the cell cultures exposed to space flight and of those under the normal gravity conditions (1 g) on the Earth has revealed some differences. The space flight conditions, mainly microgravity, induced marked changes in morphological characteristics and functional activity of the cultured fibroblasts: changes in the nucleus size and shape, retardation of cell growth and division rate. We believe that these changes may be due to weakening of intercellular contacts and cell adhesion to the substrate. These findings are important both for general biology and space medicine, specifically for the problems of tissue regeneration and wound healing under the conditions of long-term space flight.

[Potassium transport from Infusoria Tetrahymena pyriformis GL, immobilized by accelerations of 80-260 g]. / Transport kaliia iz infuzorii Tetrahymena pyriformis GL, obezdvizhennykh vozdeistviem uskorenii 80-260 g.

The effects of direct influence of gravity on a cell have been studied. Potassium transport from infusoria. Tetrahymena pyriformis GL induced by the high gravitational levels which immobilize the cell (80, 140, 260 g) was examined. A minimum acceleration level at which the cells become motionless is 80 g. Kinetics of potassium output can be described as containing "fast" and "slow" component. The rate of potassium output relating to fast component does not depend on an acceleration level but is a function of the age and density of culture. The potassium output rate associated with slow component increases as acceleration is increased. It also rises in the course of time which points to a change of internal structure of the cells occurring the more rapidly the higher level of acceleration is. Direct effect of gravity on the cell is realized by two ways: 1) effect which results from difference of densities of cell and its environment; 2) effect on intracellular structures due to difference of their densities. It is supposed that the observed effects in main are being developed at the cost of a 2nd type of gravity effect.

[An experiment with Chlamydomonas reinhardtii on the Kosmos-2044 biosatellite]. / Eksperiment c Chlamydomonas reinhardtii na biosputnike "Kosmos-2044".

Space experiment with Chlamydomonas reinhardtii demonstrated that the microgravity effects were noted in Chlamydomonas at both cellular and population levels: in space the cell size is increased, stage of active growth of the culture is extended, it contains the juvenile vegetative motile cells in greater quantities. Ultrastructural analysis indicated that in microgravity the changes in shape, structure and distribution of intracellular organelles and in volume ratio of organelles and cytoplasma are absent. Chlamydomonas data are in line with the results of the Infusoria and Chlorella experiments.

[The ecological-morphological characteristics of the growth and distribution of cultures of single-cell organisms in a gravitational field]. / Ekologo-morfologicheskie osobennosti rosta i raspredeleniia kul'tur odnokletochnykh organizmov v gravitatsionnom pole.

The paper analyses and summarizes the experimental results obtained by the authors and data accumulated in the literature during recent years in order to reveal the general regularities of the growth, distribution and behavioral parameters of the cells under conditions of reduced gravity ranged from 10(-5) to 5 g. It is indicated that an intensity of gravity effect on these parameters of unicellular organisms depends greatly on the environments, types of cells and their metabolic levels. The effects of changed gravity at the cellular level are the result of shifting the primary physiological characteristics and physicochemical parameters of the culture and cell environments as an integrated biological system.

[Gravitational sensitivity of eukaryotic unicellular organisms]. / Gravitatsionnaia chuvstvitel'nost' éukarioticheskikh odnokletochnykh organizmov.

Unicellular organisms are viewed as the best suitable objects for studying environmental effects, including the field of gravity, on living beings at the cellular level. Investigations of unicellular free-living eukaryotic organisms in gravitational and space biology help resolve both theoretical problems and practical problems associated with the design and development of biological life support systems. This paper presents experimental data about the effect of hypergravity on the structure, function and behavior of unicellular organisms--Tetrahymena pyriformis and Euglena gracilis. They were centrifuged at a rate of 87, 108 or 142 rpm to produce acceleration of 2, 3 or 5 G. The following parameters were measured: time course variations in the culture growth, rate of biomass accumulation, cell shape and size. It was found that as the gravity level grew from 2 to 5 G the culture growth was first stimulated and then inhibited. Biomass accumulation as well as the cell size and volume of Tetrahymena pyriformis and Euglena gracilis also decreased. It was demonstrated that the functional activity of cells was inversely proportional to the gravity magnitude. Potential mechanisms of the effect of hypergravity on the cell structure and function are discussed.