Zhurnal Vysshei Nervnoi Deyatelnosti Imeni I P Pavlova最新文献

Macroscopic functional network of the human brain were identified by use of the independent component analysis (ICA) of fMRI while viewing and imaging/recalling stories. The networks were relatively stable in structure, but had a specific dynamics in different experimental conditions. When comparing detected networks with previously detected resting state networks it was found that they coincide on localization. We. discovered also the specificity of activating the peripheral and central parts of retinotopic projections in the visual cortex. The peripheral areas were activated during subject viewing and imaging/recalling. On the contrary, the central departments strengthened their activation when viewing and reduced activity during the imaging/recalling.

The prestimulus expectation period of conditioned avoidance reflex features synchronized Δ-rhythm (1-4 Hz) in the medial prefrontal cortex and the ventral tegmental area (VTA), and synchronized θ-rhythm (6-8 Hz) in the above-mentioned structures and the hippocampus. According to "Granger causality" Δ- and θ-rhythms flow (are predictors) in the direction from the prefrontal cortex and the hippocampus to the VTA. Performance of conditioned avoidance reflex was marked by Δ-rhythm elimination simultaneously with generation of high-frequency (8-11 Hz) synchronized θ-rhythm. Δ-rhythm was shifted from the pre- to poststimulus period and prefrontal cortex--VTA θ-synchrony was eliminated in the cases of mistaken reaction withdrawal, Pavlovian fear conditioning scheme, conditioned signal presentation in the safe chamber part. The phase of Δ-, θ-rhythm modulates the amplitude of VTA fast (70-160 Hz) γ-activity envelope, VTA/cortex and VTA/hippocampus γ-phase synchronization and phase lag indexes, and frequency of simultaneously recorded VTA neuronal activity.

Effect of ovarian steroids on serotonin neurotransmission suggests that the modulating effect of polymorphisms of the serotonin transporter gene on brain activity in women may change with age related changes in hormonal status. Objective of the study was to identify relationships between 5-HTTLPR polymorphism of the serotonin transporter gene and characteristics of baseline EEG in healthy young women (19-35 years, N = 85) and in women in post menopause (55-80 years, N = 44). It was shown that in S'/S'(SA/SA, SA/LG) and L'/L' (LA/LA) genotypes carriers' women of the older age group had lower delta, alpha 2 and alpha 3 band power than the young. In older women genetic differences in the power of these rhythms were due to lower values in carriers of S'/S' and L'/L' compared with S'/L' genotype. S'/L' genotype was characterized by higher beta 1 rhythm power in elderly compared with young women. These results demonstrate the difference in the neurophysiological mechanisms of age-related changes in brain activity which are associated with the polymorphism of 5-HTTLPR.

In order to find objective physiological correlates of affective disorders we have carried out the complex examination of patients comparing with the control group. Psychophysiological tests, EEG and speech signal parameters have shown statistically significant difference between the groups. At clinical practice our conclusions might be used on the diagnostics stage.

Brain stem cells represent an extremely intriguing phenomenon. The aim of our review is to present an integrity vision of their role in the brain of mammals and humans, and their clinical perspectives. Over last two decades, investigations of biology of the neural stem cells produced significant changes in general knowledge about the processes of development and functioning of the brain. Researches on the cellular and molecular mechanisms of NSC differentiation and behavior led to new understanding of their involvement in learning and memory. In the regenerative medicine, original therapeutic approaches to neurodegenerative brain diseases have been elaborated due to fundamental achievements in this field. They are based on specific regenerative potential of neural stem cells and progenitor cells, which possess the ability to replace dead cells and express crucially significant biologically active factors that are missing in the pathological brain. For the needs of cell substitution therapy in the neural diseases, adequate methods of maintaining stem cells in culture and their differentiation into different types of neurons and glial cells, have been developed currently. The success of modern cellular technologies has significantly expanded the range of cells used for cell therapy. The near future may bring new perspective and distinct progress in brain cell therapy due to optimizing the cells types most promising for medical needs.

The main aim was to study effects of long-term meditation practice on event-related brain potentials (ERPs) during affective picture viewing. The meditators' (N = 20), contrary to control (N = 20), did not demonstrate arousal-related increases in the mid-latency (200-400 ms) ERP positivity over the right hemisphere. We also found in the same time window stronger ERP negativity for meditators over central regions, regardless of picture valence. We assume that long-term meditation practice enhances frontal top-down control over fast automatic detection of stimulus salience.

It has been found that long-term electromagnetic shielding (19 hours per day for 10 days) leads to an increase in the duration of passive swimming time in male rats, decrease the duration of active swimming in the "forced swim" test as well as decrease of libido. On the other hand animals kept under the "open field" conditions do not show significant deviations from their normal behavior. Therefore, one could conclude that moderate electromagnetic shielding causes a depression-like state in rats.

An important stage of learning a new skill is repetitive reproduction of one and the same sequence of movements, which plays a significant role in forming of the movement stereotypes. Two groups of right-handers repeatedly memorized (6-10 repetitions) the sequences of their hand transitions by experimenter in 6 positions, firstly by the right hand (RH), and then--by the left hand (LH) or vice versa. Random sequences previously unknown to the volunteers were reproduced in the 11 series. Modified sequences were tested in the 2nd and 3rd series, where the same elements' positions were presented in different order. The processes of repetitive sequence reproduction were similar for RH and LH. However, the learning of the modified sequences differed: Information about elements' position disregarding the reproduction order was used only when LH initiated task performing. This information was not used when LH followed RH and when RH performed the task. Consequently, the type of information coding activated by LH helped learn the positions of sequence elements, while the type of information coding activated by RH prevented learning. It is supposedly connected with the predominant role of right hemisphere in the processes of positional coding and motor learning.

The interaction (synchronization) of activity of the medial prefrontal cortex, hippocampus and basolateral amygdala have been studied in the course of performance of conditioned avoidance reflex. The pre-stimulus expectation period was characterized by low-frequency delta-activity (1-4 Hz) with the source (according to criteria of Granger causality) in the prefrontal cortex and also by synchronized theta-rhythm (6-8 Hz) in the hippocampus. The performance of conditioned avoidance reflex was characterized by generation of high-frequency synchronized theta-rhythm (8-11 Hz) simultaneously with delta-activity elimination. The phase of delta- (theta-) activity modulates the envelope of gamma-rhythm (~30-120 Hz) in each of the structures. The elaboration and strengthening of conditioned reflex leads to concurrent theta power and synchronization growth in relation to reflex performance, but not during the prestimulus expectation period.

Coherent activation of limbic system structures as the main function of theta-rhythm is widely discussed in the literature. However until now does not exist the common view on its generation in these brain structures. The model of septal theta-rhythmic activation and control of limbic structures is suggested basing on the literature and own experimental data.