Zhurnal Vysshei Nervnoi Deyatelnosti Imeni I P Pavlova最新文献

Using optical imaging technique and method for histochemical cytochrome oxidase revealing we investigated in three kitten's groups (two experimental and one control) a rhythmically light stimulation on ontogenetic development of orientation columns and cytochrome oxidase blobs in visual area 18. Experimental animals were stimulated by rhythmical light for 3 hrs or 12 hrs per day respectively. It was first obtained that binocular co-activation per se, not accompanied by strabismus, indeed influences cortical columns formation during critical period. We show an opposite effect of stimulation on two different types of cortical columns, and also revealed that these affects are have retained for at least 2 weeks after stimulation was terminated. It was obtained that duration of rhythmically light stimulation determines a volume of functional and anatomic alterations: alterations revealed were more pronounced in animals stimulated for12 hrs per day.

The data of epigenetic studies of stress reactivity and resilience in the pathogenesis of depression in experimental animals and humans subjected to stress at different periods of life are analyzed. Specific chromatin modifications, first of all histone acetylation and methylation, are controlling expression of definite genes in distinct brain structures. Epigenetic modulation of particular genes related to development of pro-depressive or antidepressive stress response are discussed (5HT transporter and receptors, corticotropin releasing hormone, glucocorticoid and their receptors, BDNF and other neurotrophic factors).

The aim of this investigation is to study neurophysiologic mechanisms of processing of relevant words and unknown words. Event-related synchronization/desynchronization during categorization of three types of stimuli (known targets, known no targets and unknown words) was examined. The main difference between known targets and unknown stimuli was revealed in the thetal and theta2 bands at the early stage after stimuli onset (150-300 ms) and in the delta band (400-700 ms). In the late time window at about 800-1500 ms thetal ERS in response to the target stimuli was smaller than to other stimuli, but theta2 and alpha ERD in response to the target stimuli was larger than to known nontarget words.

The analysis of neuromorphological, neurophysiological, neurocognitive and neuropsychological data demonstrates the specific involvement of lateral, medial, orbital and rostral parts of prefrontal cortex in the selective regulation and organization of goal-directed behavior. Functional specialization of different prefrontal areas depends on their co-operation with posterior associative cortices and subcortical brain structures such as the mediodorsal thalamic nucleus, hippocampus, amygdale and basal ganglia. Separate cortical and subcortical structures are included in functional networks which provide different aspects of the brain executive functions.

The present study was aimed, first, at developing a visual switching task for fMRI research and, second, at identification of the brain regions involved in task switching. Forty eight healthy individuals (from 21 to 56 years of age) participated in the study. The designed visual switching task was relatively short, it consisted of an easy stimulus set and involved a simple condition, in which participants had to shift their attention between two task conditions (classifying figures according to their form or number). Thus, this developed testing procedure can further be used to assess special populations, including patients with brain damage who cannot do monotonous tasks for a long period of time and have language impairments. The results of this testing technique revealed that task switching is carried out by an interconnected neuronal network, consisting of dorsolateral prefrontal cortex, inferior parietal area, secondary visual area, supplementary motor area and cerebellum cortex of both hemispheres.

The spectral characteristics of the EEG recorded on two professional pilots in the simulator TU-154 aircraft in flight dynamics, including takeoff, landing and horizontal flight (in particular during difficult conditions) were analyzed. EEG recording was made with frequency band 0.1-70 Hz continuously from 15 electrodes. The EEG recordings were evaluated using analysis of variance and discriminant analysis. Statistical significant of the identified differences and the influence of the main factors and their interactions were evaluated using Greenhouse - Gaiser corrections. It was shown that the spectral characteristics of the EEG are highly informative features of the state of the pilots, reflecting the different flight phases. High validity ofthe differences including individual characteristic, indicates their non-random nature and the possibility of constructing a system of pilots' state control during all phases of flight, based on EEG features.

EEG study of 5-7 years boys with autism revealed lower values of coherence in background delta, theta and alpha bands and higher values of coherence in background beta 1, beta 2 and gamma bands. Healthy boys showed higher values of beta and gamma coherence during cognitive task. Autistic persons demonstrated higher values of theta coherence during cognitive task.

EEG rhythmical picture of subject's movement suppression and spatial-figurative task solving was examined and analyzed. Rhythms appearing during spatial reasoning and suppressed movements with the frequency of about 11 Hz were isolated. It was hypothesized that a functional link exists between these rhythms in the considered behavioral tests. To test the hypothesis and to reveal this connection, experiments were developed and carried out. Then the analysis of recorded EEG signals was conducted by applying Fourier transform, independent component analysis (ICA) and equivalent dipole source localization. Unexpected conclusion about the existence of a general mechanism of movement suppression was drawn.