Functional development of the vegetative regulation of the cardiovascular system in human ontogenesis

Using the functional tests method, it was shown that the ontogenetic course of development of the cardiovascular system vegetative regulation after the age 6 years might be conditionally divided into some periods. About the age of 13-14 years, the spectral structure of heart rate variability reached the level of adult humans but is accompanied with features of functional strengthening in regulative systems. About the age of 15-16 years, maturation of indices received in quiet state (heart rate, stroke volume, spectral and statistical parameters of heart rate variability) is reached. At the same time, the functional maturation of heart rate regulating systems was complete thereby providing adaptive response of the organism during the implementation of functional tests. Functional maturation of peripheral blood pressure and the systems of its regulation completed after 16 years.     

Characteristics of the myocardium functional state and cerebral circulation of seven- to ten-year-old children with different variants of autonomic nervous regulation of the heart rate

A complex study of the functional state of the cardiovascular system of seven- to ten-year-old children with different types of autonomic nervous regulation of the heart rate was performed. It was found that the autonomic nervous system strongly affects the adaptive capacity of the body, bioelectrical processes in the myocardium, the duration of cardiac-cycle phases, the pulse volume, and the tone of large and small cerebral vessels.     

Estimation and prediction of functional changes in organisms in space flight

The article is devoted to theoretical and applied problems of estimation of the organism functional state and a level of health. Transitive states between health and illness, between norm and a pathology, so-called prenosological states are considered. The level of health is determined by adaptable opportunities of an organism, a degree of regulatory systems tension and their functional reserve. As the basic methodical approach to an estimation of a degree of regulatory systems tension the method of heart variability analysis is described. The applied aspect of a considered problem is submitted by results of the researches which have been carried out in conditions of space flight. Changes of organism functional state at different stages of adaptation to conditions of long weightlessness are described. The mathematical model of functional states is submitted. Four types of the vegetative regulation, differing on the adaptive reactions in conditions of space flight are allocated. Results of researches of crew members of the International space station are submitted.     

The durations of the phases and periods of the cardiac cycle in athletes as dependent on the specific type of training

Polycardiography was used to analyze cardiac cycle phases in young track athletes during a two-year training cycle. The subjects were examined in the state of relative muscular rest and during moderate bicycle ergometer exercise. It was found that track training leads to a decrease in the heart rate and regulatory myocardial hypodynamic syndrome. Adaptive rearrangements in myocardial contractility were observed; they depended on the age of athletes and the type of training during the training macrocycle. The performance of the test with a moderate intensity was accompanied by a hyperdynamic syndrome, the degree of its manifestation depending on the age of the subject and the exercise intensity.     

The athlete's heart Part I (Review)

Importance of the athlete's heart has been arisen in the last decades.

Consequences of the sedentary way of life are the most threatening through the impairments of the cardiovascular system. Endurance performance is mostly limited by the characteristics of the athlete's heart. Sudden death of the athletes is always associated with cardiac disorders.

Main characteristics of the athlete's heart can be divided into morphologic, functional and regulatory ones.

The main morphologic characteristics are the physiologic left ventricular (LV) hypertrophy and a richer coronary capillary network. The functional adaptation contains a better systolic and diastolic function, modified metabolism and electric characteristics. The most easily detected modification is the better LV diastolic function. Adaptation of the cardiac regulation is manifested mostly by a lower heart rate (HR).

Summarizing: the athlete's heart is an enlarged but otherwise normal heart characterized by a low heart rate, an increased pumping capacity, and a greater ability to deliver oxygen to skeletal muscle.     

Functional characteristics of hemodynamics in adolescents under the conditions of different motor activities

The formation of functional systems in correspondence with the conditions of natural activity is the most important issue of developmental physiology. In this study, data on the assessment of the state of central and cerebral hemodynamics, as well as indices of spectral analysis of the heart rate’s variability (HRV) in adolescents depending on the level of motor activity has been collected and systematized. The possibility of integration of methods of rheoencephallography and cardiorythmography for the assessment of the characteristics of the ontogenetic formation of the cardiovascular system has been studied. Analysis of the formation of indices of hemodynamics during an academic year and the training cycle in swimmers and healthy adolescents who do not enroll in sports classes has been made. Changes in, and correlations between, the parameters of central hemodynamics and cerebral circulation, as well as parameters of HRV, have been detected. Analysis of the changes in the statistical indices of the cardiac rhythm in adolescents during an academic year on the basis of the qualitative and quantitative characteristics of the state of regulatory systems, as well as the determination of the direction of the response to the combination of academic loads and the factor of physical training, permitted a detailed study of changes that take place in some hemodynamic parameters in athletes and students, which is of particular importance for the diagnosis of their functional state.     

Study of the autonomic regulation of blood circulation during a long-term space flight

The five-year experience of experimentation in the autonomic regulation of blood circulation on board the International Space Station is presented. The heart rate variability (HRV) analysis was the basic methodical approach in these investigations. The probabilistic approach to the estimation of the risk of pathology under long-term spaceflight conditions based on HRV analysis is described. The individual type of autonomic regulation was taken into account in the analysis of the results of the investigations. The type of regulation inherent in every cosmonaut under the conditions of weightlessness has been shown to be retained during subsequent flights. New scientific data on the relationship between the character of the adaptive response of the body to spaceflight factors and the individual type of autonomic response have been obtained. Staying in weightlessness has been shown to be connected with the readjustment of regulatory systems and with transition to the zone of prenosological states. Adaptation responses in weightlessness are characterized by the increased tension of the regulatory systems and the preservation of sufficient functional reserves. The mobilization of additional resources is required after returning to earth, due to which the functional reserve of the mechanisms of regulation decreases. Cosmonauts with the vagotonic and normosympathotonic types of autonomic regulation appear to be the most resistant. The knowledge of the type of autonomic regulation allows us to judge the potential response of the cosmonaut to spaceflight factors. The likelihood estimates were calculated, and the risk categories were determined by the results of HRV analysis in the last months of the flight. Three pathology risk groups were identified. In conclusion, the theoretical and applied significance of the experiments was considered.     

The psychophysiological condition of first year students with different levels of physical activity

The psychophysiological condition of (male) first year students who participate in sport or don't participate in sport during studies was studied. R. M. Bayevsky's method was used to establish the level of stress on regulatory mechanisms. The functional level of the nervous system, stability of neural responses, and the level of functional abilities of the developed functional system were evaluated using the variation chronoreflexometric method. It was established that an improvement of mental capacity indicators (increase of memory capacity, reduction of the amount of mistakes made, growth of the level of functional abilities and reduction of the latency period of the visual-motor response) was accompanied by a growth of stress on the body's regulatory systems which was more pronounced with regard to those test participants whose level of physical activity was low. This fact is proof that physical activity reduces the body's "adaptation price" to the changing conditions of the environment. The optimal realisation of a person's adaptive systemic reactions is provided for by the dynamic interaction of the functional systems, which form a complex correlation in the body's somatovegetative, motor and psychoemotional spheres of activity.     

Integration of Functional,Psychophysiological, and Biochemical Processes in Athletes after Audiovisual Stimulation

We studied intra- and inter-system structural interactions between functional, psychophysiological, and biochemical processes in athletes after audiovisual stimulation (AVS). We used multiple linear regression and correlation analysis after AVS to investigate the formation of new relations between the nervous, hormonal, cardiorespiratory, and metabolic systems. AVS training leads to an increase in physical working capacity (PWC₁₇₀) and in the number of its correlations, e.g., with the amplitude of alpha-rhythm, resting heart rate (HR), concentrations of thyroxine, phosphorus, glucose, bilirubin, and triglycerides, antioxidant status, and the level of life satisfaction, which indicates the elevation in inter-system integration processes at different functional levels. An increase in the number and effects of factors contributing to PWC₁₇₀ (chronoinotropic reserve, lung capacity, reaction of individual α-rate power depth, reaction to the moving object, and the concentrations of glucose, creatinine, bilirubin, and thyroxine) eventually resulted in higher PWC₁₇₀. This indicates that the rate of synchronization between the studied parameters increases under the influence of sensory impact, which results in the improvement of adaptive capacity and provides a lower cost of adaptation to physical loads at the competitive stage of sports training.     

Effect of motor load on the course of functional maturation of the autonomic control of the cardiovascular system of adolescents

A comparative study of the state of the cardiovascular systems of adolescents not engaged in sports and young athletes of the same age has been performed. According to the indices recorded in the resting state, a relative lag of the functional development of the systems of autonomic control of the cardiovascular system was shown for adolescent nonathletes at an age of 13–14 years as compared with young athletes. This lag is compensated by the age of 15–16 years, but the adequate level of autonomic activity is reached through the activation of central regulatory mechanisms (sympathetic and humoral), with a relatively low contribution of the peripheral vagal and baroreflex mechanisms. This conclusion is confirmed by the results of assessment of the reactivity of the cardiovascular system of adolescents with different levels of motor activity in a functional test with limited pulmonary ventilation.     

Adaptive Transformations of the Heart Rhythm Regulation and Structure of Behavioral Acts after Glycine Administration

The aim of this study was investigation of adaptive alterations in the structure of heart rhythm regulation, the functional levels of memory, and the dynamic characteristics of behavior after the administration of glycine. The heart rhythm variability, using standard statistical techniques of autocorrelation and spectral analysis, was analyzed. Nonsymbolic testing of the visual memory in three visual pattern (7 + 2) exposure modes was also assessed, where the number of correct and incorrect responses and temporal characteristics were calculated. Assessment of the functional state was conducted using dynamic characteristics of the behavioral act in stochastic and deterministic environments and involved measurement of the total response rate, its variance, and differential characteristics of decision making given repeated choices and during choice assessment after successful and unsuccessful trials. Healthy subjects 35–45 years old (7 males and 10 females) were tested before and after sublingual administration of glycine, 0.2 g two times a day, for three weeks. It was found that the sympathetic contribution to the heart rate regulation increased after the administration of glycine and was more pronounced in females. The rate of cognitive processing also significantly increased with an increased plasticity of prognostic self-regulation in all subjects and increased the sensitivity in a stochastic environment in females.     

Structural and functional characteristics of the heart of professional soccer players after retirement from long-term sports activity

The structural and functional characteristics of the heart of 51 retired soccer players who ceased training 3–15 years ago are presented. A number of structural and functional signs of “athlete’s heart” detected in the subjects indicate more efficient heart functioning at rest and during exercise. The myocardium requires less oxygen per unit power of muscle work, and each gram of the myocardium of retired athletes performs more mechanical work than the myocardium of untrained subjects of the same age. This indicates long-term adaptation of the heart of retired athletes to muscle work. The heart functioning at rest and during exercise in retired athletes becomes less efficient with age, this trend being more pronounced in older former athletes than in younger ones. This is expressed in an increased oxygen consumption by the myocardium, a higher occurrence of atypical electrocardiogram patterns, age-related changes in myocardial contractility, and a decreased capacity of each gram of the myocardium for generating mechanical work.     

Age-dependent heart rate variability in preschool children living under the conditions of the European Arctic region

The results of analysis of specific characteristics of the heart rate variability (HRV) regulation in preschool children living under the Arctic high-latitude conditions are presented. The principal ageand gender-specific differences in the HRV regulation have been inferred from the intergroup evaluations of the HRV indicators in boys and girls. A functional developmental delay has been shown in 2.5-year-old girls compared with boys of the same age group. The applied orthostatic test has shown lower reserve capacities in children of the senior group compared with the junior group. It has been shown that the mechanisms of the regulation of cardiac rhythm in girls experience higher strain during orthostasis as compared with boys. The division of children into age groups with an age difference of one year has allowed the detection of the tendency towards basically different responses to functional loads during orthostasis. The mean HRV values characteristic of four- to six-year-old children living in the Arctic are presented. It has been shown that the children living at middle latitudes have a higher adaptive potential compared with the children living in high-latitude Arctic areas.     

Effectiveness of physical exercises for regulation of the functional state of six- to eight-year-old anxious children

The study aimed at optimizing the functional state (FS) of anxious six- to eight-year-old children showed that integrated use of physical exercises of a mainly aerobic character, relaxation training, respiratory exercises, and functional music is more effective in the long-term aspect than selective use of these means. Only physical exercises exert a marked influence in the FS of six- to eight-year-old anxious children under a stressful informational load. The use of other means of optimizing the FS appears to be less effective. The high effectiveness of physical exercises is determined by adaptive changes in the mechanisms of FS regulation in anxious children. Apparently, long-term adaptation to an adequate muscular activity ensures improved functioning of, and a better interaction between, the activating and inactivating structures of the modulating brain system located at different levels of the CNS, in particular, in the frontal cortical areas. It is emphasized that the peculiarities of the influence of different means of regulation of the FS on the body of anxious elementary school children are, largely determined by the immaturity of the frontothalamic regulatory system and the specifics of the functional organization of the limbic brain structures.     

Seven-day dry immersion: Interrelationship between the changes in the water-electrolyte balance and cardiovascular responses

The results of an experiment with a seven-day dry immersion are presented. Eight healthy men were examined before, during, and after the exposure. It was shown that the primary response involved hemodynamic and water-electrolyte changes. The mechanisms of cardiovascular adaptation to the immersion conditions were revealed. In particular, some electrophysiological shifts in the propagation of myocardial excitation were found, leading to an increase in the variance of natural small oscillations of the electric potential of the heart. The revealed significant reduction of the functional reserves of the cardiovascular regulatory mechanisms during adaptation to dry immersion is of great practical importance. The results suggest that the water-electrolyte balance shifts induced by dry immersion are the basis and the first phase of further changes in the autonomic regulation and functional state of the myocardium.     

心肌细胞发育过程中胞浆内钙稳态的调控

Ca^2＋信号是细胞和各器官生长发育、行使其生理功能的基础,维持心肌细胞的钙稳态是保持正常心脏功能的先决条件。作为在胚胎发育过程中最早出现并行使功能的器官,胚胎期心脏的形态结构发生了明显的变化,泵血功能不断增强,以适应不断增强的机体的生理需求。从胚胎到成年,心肌细胞的功能有非常大的改变,各钙离子通道的表达也发生明显变化。因此,发育早期心肌细胞的钙稳态调控与成熟心肌细胞有明显的不同,在发育过程中引起细胞收缩的Ca^2＋来源也有明显的变化。随着分子和细胞生物学研究的发展,以及胚胎干细胞体外分化模型的应用,人们对心肌细胞发育过程中钙稳态的调控有了进一步的认识。本文综述了早期心肌细胞发育过程中胞浆内钙稳态的变化,总结了早期心肌细胞钙稳态调控机制的最新研究进展。     

A Broad-Based Estimation of the Physical Work Capacity of Young Men

The physical work capacity of young men (17–21 years old) was estimated during this broad-based study. The subjects were divided into two groups depending on the level of their motor activity: those who were in general sport fitness programs (166 subjects) and those who had achieved high recognition in sports (149 subjects). Two stages in the development of physical work capacity in young men were detected. The first stage covered the 17- to 18-year-old men and was characterized by a significant increase in physical development and aerobic capacity, the improved hemodynamic responses to physical exercise, and a high tension in the cardiac regulatory mechanisms. The second stage (18–21 years) was a period of relative stabilization of physical development and body functions, during which the organism came to a new functional level typical of adulthood. A comparative analysis of the physical work capacity in subjects with different levels of motor activity showed that the indices of physical development, physical fitness, and aerobic capacity in 17-year-old athletes exceeded the same indices in the untrained age-matched group. Physical work capacity was significantly higher in athletes than in the untrained subjects during the whole juvenile period. In athletes the age-related physical fitness and aerobic capacity increased to a greater extent but physical development increased to a lesser extent than the same in the untrained subjects.     

A population dynamics analysis of the interaction between adaptive regulatory T cells and antigen presenting cells

Background

Regulatory T cells are central actors in the maintenance of tolerance of self-antigens or allergens and in the regulation of the intensity of the immune response during infections by pathogens. An understanding of the network of the interaction between regulatory T cells, antigen presenting cells and effector T cells is starting to emerge. Dynamical systems analysis can help to understand the dynamical properties of an interaction network and can shed light on the different tasks that can be accomplished by a network.

Methodology and Principal Findings

We used a mathematical model to describe a interaction network of adaptive regulatory T cells, in which mature precursor T cells may differentiate into either adaptive regulatory T cells or effector T cells, depending on the activation state of the cell by which the antigen was presented. Using an equilibrium analysis of the mathematical model we show that, for some parameters, the network has two stable equilibrium states: one in which effector T cells are strongly regulated by regulatory T cells and another in which effector T cells are not regulated because the regulatory T cell population is vanishingly small. We then simulate different types of perturbations, such as the introduction of an antigen into a virgin system, and look at the state into which the system falls. We find that whether or not the interaction network switches from the regulated (tolerant) state to the unregulated state depends on the strength of the antigenic stimulus and the state from which the network has been perturbed.

Conclusion/Significance

Our findings suggest that the interaction network studied in this paper plays an essential part in generating and maintaining tolerance against allergens and self-antigens.     

Adaptivity of social systems: the problem for scientific research

The notion of adaptive evolution of social systems as of a real process of selection of the properties of such systems implies group selection. But strong evidences of effective group selection seem impossible, at least in vertebrates. However, understanding the origin of social systems adaptivity based on individual selection is difficult, as well, without analyzing the proximal mechanisms of the formation of such systems. I suppose that social systems change due to changes of individual features that underlie the proximal mechanisms of the system formation. These features are the characteristics of neurophysiological and hormonal regulatory mechanisms. They are strongly associated with intrinsic biochemical processes and are coded in the genome. Thus, the evolution of social systems is the evolution of their proximal mechanisms. At the same time, the specificity of neurophysiological and hormonal regulation determines not only social interactions, but also the individual behaviour of animals. The most important characteristics of life history, such as the regime of activity, foraging strategy, etc., are strongly affected by the same regulatory mechanisms. This view is useful for understanding the relations combining many features into an integrated and adaptive species-specific life form. I suppose that such forms emerged as evolutionary consequences of changes in regulatory mechanisms adaptive to specific environment. Thus, we have as substantial reasons to discuss adaptations of social systems to ecological features as to discuss ecological features adapted to particular social systems. The species-specificity of regulatory mechanisms is probably based on different kinds of evolutionary choice between the rapidity and the perfection of adaptation, between flexibility and stability, and between sensibility and resistibility. I think that this choice depends largely on the predictability of the environment. The less predictable it is, the more it increases the selective value of sensibility, flexibility, and rapidity of evolution. On the contrary, stable and predictable environment stimulates less rapid but more perfect adaptations. Such choices consolidate in the genome during evolution as specific features of neurophysiological and hormonal regulation systems. These specific features, in their turn, determine ecological, behavioural, and physiological species-specificity. From this point of view, evolutionary changes in social systems can be readily perceived as consequences of the selection of individuals, promoting optimal properties under particular conditional features of regulation systems. The boundary condition for this model is the absence of specificity of the characteristics of regulation systems to different forms of stress. This condition needs to be considered closely.     

Psychophysiological condition of first-year students with different levels of physical activity

The psychophysiological condition of first-year students (males) going or not going in for sport in the course of training was investigated. Baevskii’s method was used to determine the level of stress of regulatory mechanisms. The functional level of the nervous system, the stability of neural responses, and the level of functional abilities of the developed functional system were evaluated using the variation chronoreflexometric method. It was established that an improvement in the mental capacity parameters (increased mental capacity, reduction in the number of errors, an increase in the level of functional abilities, and shortening of the latent period of visuomotor response) was accompanied by an increase of stress of the body regulatory systems, which was more marked in individuals with a low level of physical activity. This fact indicates that physical activity reduces the cost of the adaptation of the body to permanently changing environmental conditions. The optimal human adaptive systemic reactions are ensured by the dynamic interaction of the functional systems forming complex correlations in the somatic, autonomic, motor, and psychoemotional spheres of the body’s activity.