Vol 43, No 3 (2017)

The neurophysiological mechanisms underlying retention of creative potential during aging are still poorly studied. Previously, we have identified age-related changes in the temporal dynamics of brain activity and the speed of creative problem solving at its initial stage, suggesting that younger and older subjects used different strategies. These differences in strategies may also be observed at the final stage of problem solving. Therefore, we have studied the pattern of temporal changes in the EEG spectral characteristics (event-related spectral perturbation, ERSP) in younger (N = 89, 22.1 ± 3.2 years) and older (N = 90, 64.9 ± 6.7 years) age cohorts during 600 ms before the preparation to motor response, which indicates that solution is found. The general and ageand sex-related features of the oscillatory brain activity at the final stage of problem solving were revealed. All subjects displayed statistically significant EEG temporal dynamics associated with a reduction of power reactivity of rhythms prior to the response. The age-related differences included more pronounced ERSP frontal–parietal gradient in the θ frequency range and lower ERSP values in the β frequency range in elderly subjects as compared with the younger individuals. The most pronounced age-related differences in the β₁ rhythm were observed in the posterior cortex. The age-related differences in the α₃ frequency range were mediated by the sex factor: lateral differences were pronounced only in young men, and the coefficient of hemispheric asymmetry in this group differed significantly from that in older men and younger women. These data reflect the changes in EEG that were associated with the evaluation of creative idea, making a decision about completion of the search, and intention to make a motor response that indicates that solution is found.

We continued our study of the mechanisms of visual acuity (VA) in ontogenesis. We measured the VA and sensitivity to lines orientation and determined the minimal length of lines for discrimination of the vertical and the horizontal ones in subjects aged 7–25 years. It was found that the thresholds of discrimination of vertical and horizontal lines in subjects with normal VA decreased with age up to 9–10 years and then remained constant, while the orientation selectivity was improving up to the age of 14–16 years. The average VA almost did not depend on age. Individual thresholds of line lengths and orientation discrimination correlated with the VA of subjects.

We studied the frequency and amplitude properties of the EEG μ rhythm in children (n = 38) aged 4–14 years under the condition of visual fixation (VF) on a video image of a computer mouse, as well as the parameters of its desynchronization during the tasks involving self-controlled performance, observation, imitation, and auditory recognition of the hand circular movements (SPM, OM, IM, and ARM, respectively) with a computer mouse. We observed age-related increment in the modal frequency of μ rhythm in loci C₃ and C_z. During the SPM process, a significant decrease in the amplitude of μ rhythm was found in loci C₃ (26.7%) and C_z (10.3%); during the OM, in locus C_z only (9.9%). The effects of the μ rhythm desynchronization during both self-paced and observed movements might be an evidence of well-developed neural matching mechanisms that provide the processes of performing and observing similar actions in children aged 4 to 14 years. During the IM, the desynchronization of μ rhythm was significant in loci C₃ (27.4%) and C_z (15.3%). We hypothesize that the statistically significant increase (from SPM to IM) in the depression of μ rhythm in locus C_z is likely to be an effect of a social gaming context common for the situations when children imitate the movements of adults. The index of desynchronization of μ rhythm under the studied conditions did not depend on the age of children. Possible relations of identified modulations of the μ rhythm to the activity of the mirror neuron system were also discussed.

The goal of this study is to compare the dynamics of aerobic and force–velocity characteristics of the shoulder girdle muscles and leg muscles during high-volume aerobic training in junior cross-country skiers in the time interval from the end of the preparatory period to the beginning of the competition period. Eleven junior cross-country skiers were repeatedly tested from December to February. In this period, the volume of aerobic training was 22–23 h per week. During the experimental period, the knee extensors torque in the range of angular velocities of 30–300 degrees/s was observed to decrease, with no changes in the volume of the quadriceps muscle of thigh and knee flexor muscles. The maximal oxygen consumption rate (VO₂ max) was observed to decrease by 6% (P < 0.05) in the treadmill test, while the oxygen consumption at anaerobic threshold (VO₂ at La = 4 mmol/L) was unchanged. On the contrary, the functional capacity of the shoulder girdle muscles was enhanced. The force-velocity characteristics of the shoulder girdle muscles that were estimated in the maximal anaerobic power test at a double poling ergometer increased by 16% (P < 0.01), and the volume of the triceps muscle of arm increased by 4.6 (P < 0.01). The aerobic capacity of the shoulder girdle muscles that were estimated by the VO₂ at La = 4 mmol/L increased by 30% (P < 0.05). The potential for increasing the performance of junior cross-country skiers seems to be associated with the increased functional capacity of the shoulder girdle muscles.

High stress level in the mechanisms responsible for adaptation to physical work affects the human immune system. Therefore, the effectiveness of countermeasures of reduced physical activity was studied using some parameters of the immune system. Our purpose was to examine how different types of exercises can modify physical performance and immune function in six subjects volunteered for Mars-500 simulation study. During the study, the resistance and cyclic training alternated over the period of about two months. According to the design, training was interrupted twice by an interval of approximately one month. The training plan was developed so that the initial and final stages of isolation could not impair the effectiveness of training. The cyclic training included running on the motorized and non-motorized treadmill and bicycling. Resistance exercises were performed using the MDS multifunctional exercise machine, expanders, and the Galileo 2000 vibration plate. Physical performance was assessed by the criteria of maximal voluntary effort, incremental locomotion, and bicycle exercise tests. Analysis of the quantitative and functional properties of effector cells of both innate and adaptive immunity was employed to investigate the immune status of subjects. Due to the plan of physical training, the level of physical performance in isolation was better than during the baseline data collection, although the intervals caused a considerable decrease in performance. Comparison of immunograms with the baseline ones showed positive changes: the number of naive CD4⁺Т-cells (CD4⁺CD45RA⁺) increased significantly. The functional activity of adaptive immunity did not reduce during isolation; on the contrary, the ability of T cells to express the early activation marker CD69⁺ on the surface was increased. The immune status parameters assessed in the subjects in the second half of the isolation period indicate that the proposed physical loads were adequate. In addition to retention of the baseline level of, or improvement in, physical performance, positive activation of the T component of adaptive immunity was observed.

The paper reports a search for association between the relative bone tissue mass (percent of total body mass, %BT) and FokI (rs10735810), BsmI (rs1544410), and TaqαI (rs731236) vitamin D receptor gene polymorphisms. The group of apparently healthy young adults born in the central and northern regions of European Russia included 61 men and 60 women aged 16–23 years. No statistical association was detected between the FokI polymorphism and %BT. The carriers of the BsmI *A allele exhibited a higher %BT (p = 0.0172) compared to the subjects bearing the BsmI *G*G allele. The subjects with the *C*CTaqαI genotype were characterized by increased %BT compared to the carriers of the *T allele (p = 0.0018). The data are in good correspondence with the results obtained in the studies involving apparently healthy representatives of Central European and Northern European populations of the corresponding age.

Serum levels of cytokines and antibodies (ABs) to neuronal proteins and their relationship were studied in patients with chronic mercury intoxication (CMI) varying in severity. CMI development was observed to worsen the imbalance of pro- and anti-inflammatory cytokines, and the cytokine levels proved to reflect the severity of the pathological process. The relationships (positive and negative correlations) between cytokine and neuronal AB concentrations and their dependence on the severity of neurointoxication with elemental mercury vapor were assumed to indicate that a distorted cytokine regulation of autoimmune processes plays an important role in mercury neurotoxicity.

Olfactory testing was performed in two groups of young men aged 18–22 years with and without sexual experience. Multichannel EEG was recorded at rest and upon the presentation of 45 natural body odors of young women in different phases of the menstrual cycle. The odors were either intact or mixed with J’Adore L’Absolu perfume (Christian Dior) with or without a female pheromone. Changes in spectral power within narrow frequency ranges in response to olfactory stimulation were estimated by multivariate analysis of variance. It was found that background electrical activity of the brain in young men with regular sex life had lower spectral power in all frequency ranges. The EEG responses to the intact olfactory stimuli in all young men were associated with a decrease in spectral power in the majority of the frequency ranges and especially in the θ₂ and high- and low-frequency α rhythms. Presentation of female odors masked with a perfume resulted in bidirectional EEG responses; i.e., the spectral power in the θ₁ and β₁ ranges increased or decreased depending on the sexual experience of men and the menstrual cycle phase of a female donor as compared with an intact odor. The comparison of the EEG responses to intact or perfume-masked odors showed that individual odor remains dominant.

Healthy subjects (n = 83) performed a task involving reproductive imagination (remembrances): they were asked to remember and to have an imaginary walk along a well-known road (a real walk, the reproductive imagination state, RIS). Then the subjects performed a task involving productive imagination: they were asked to imagine a city that does not actually exist and to have an imaginary walk through it (a fictitious walk, productive imagination state, PIS). The reference values were measured at rest with the eyes open (REO). Monopolar EEGs were recorded from 19 areas of the scalp surface (10–20 system). An increase in EEG power in the α₂ frequency range during RIS and even more pronounced increase during PIS as compared with REO were considered to reflect the internalization of attention. We also observed multidirectional dynamics of EEG power in the θ and α1 ranges during PIS and RIS as compared with REO, which suggests the dominance of free associative manipulation of visual images in PIS in contrast to RIS, where algorithmically ordered operations with visual images stored in the memory were dominant.