Vol 76, No 1 (2026)

The article examines the evolution of the principles of symmetry and asymmetry that are the most fundamental properties of the external and internal structure of Metazoa or multicellular animals. The evolutionary background and advantages of bilaterally symmetric animals are logically justified. It has been noted that in the internal structure of the body, bilateral symmetry is not dominant, and the structure of the internal organs follows its own laws determined by their functions. The increase in asymmetry in the morphophysiological evolution of the vital organ of the heart is shown in detail that ensured the separation of the flows of highly oxygenated arterial and venous blood and led to the emergence of warm- bloodedness. It is emphasized that the morphophysiological evolution of the central nervous system, characterized by the emergence of lateralization and then functional asymmetry of the cerebral hemispheres, becomes a decisive factor for the evolutionary success of vertebrates. In Homo sapiens the functional asymmetry reaches its maximum development due to the localization of the speech and auditory- speech centers in the left hemisphere (for right- handed individuals and most left- handed individuals), which determines its dominance in conscious activity. The article presents evidence that impaired functional asymmetry of the brain, with a leading deficit in right- hemisphere functions, is a key risk factor in the development of various types of deviant or "abnormal" behavior.

The aim of this study was to explore the discriminatory potential of resting-state EEG in distinguishing between children and adolescents aged 3 to 19 years with Fragile X syndrome (FXS), autism spectrum disorders (ASD), and typical development (TD), using spectral EEG analysis. Resting-state EEG was recorded from 16 standard 10-20% electrode locations in 69 participants with FXS, 120 with ASD, and 700 typically developing participants. A linear discriminant analysis was conducted using the BrainSys software package for EEG analysis and topographic mapping. Significant spectral differences were observed between the ASD and FXS groups, including lower theta-band power in ASD compared to FXS, and higher power in the alpha and beta-1 frequency bands. Both clinical groups also showed distinct spectral characteristics compared to the TD group. Notably, resting-state EEG demonstrated a strong predictive ability in distinguishing FXS from ASD, with a sensitivity of 94% and a specificity of 85%, based on three key predictors. FXS participants showed a distinct EEG profile characterized by increased theta and beta-2 power and reduced alpha power. The linear discriminant analysis reliably classified subjects into ASD, FXS, and TD groups with high specificity and sensitivity. These findings support the validity of EEG as a biological biomarker for both FXS and ASD. The identified spectral patterns may contribute to clinical evaluation protocols and serve as valuable tools in intervention studies.

We have previously shown that the gaze is fixed on areas of the face that are distinguished by the greatest increment in the total contrast. The total contrast is understood as the sum of the contrasts of all luminance gradients in the analyzed area of the image, and its increase is estimated as the difference with the total contrast of the surrounding area. To prove that these areas are determined preattentively as targets of attention, in the present work we used stimuli in which the areas of interest could not be predetermined endogenously based on the semantic properties of the image. The subjects were presented with fragments of natural scenes. For each stimulus, averaged maps of the distribution of fixation density were constructed. In addition, the images were processed using a program that determines the distribution of the values of the sum contrast across the image. For each spatial frequency, 2 two-dimensional maps of the localization of areas characterized by the greatest (max) and the smallest (min) increment in the sum contrast were constructed. Empirical maps were compared with the calculated min and max maps using two complementary metrics — CC and NSS. It turned out that the similarity of the calculated and empirical maps significantly increases with increasing difference of the total contrast of the selected areas. Then we compared the max maps with the “ran” maps obtained by randomly placing the “areas of interest”. And again, the similarity of the distribution of the empirical maps with the max maps was significantly higher than with the ran maps. It is concluded that the targets of exogenous attention are image areas with the greatest increment in the sum contrast. These salient areas are automatically selected from the input image in different spatial-frequency ranges by second-order visual filters that combine information about local luminance gradients.

Despite its subjective nature, pain has long been viewed primarily from a biomedical perspective. Consequently, the social and psychological dimensions of pain were disregarded in both pain syndrome research and therapy. However, clinical practice has revealed certain phenomena, such as placebo-induced hyperalgesia or hypoalgesia, which cannot be explained solely by anatomical structures and physiological processes. The advent of the "gate control" theory of pain and the evolution of the biopsychosocial approach furnished a conceptual alternative that became the prevailing paradigm, resulting in the incorporation of cognitive and social factors influencing pain perception in research. This review explores the role of social, emotional, and cognitive factors in the experience of pain, with a focus on clinical applications. The analysis methodically organizes data, thereby substantiating the necessity for a comprehensive biopsychosocial understanding of the development and modulation of pain. A comprehensive understanding of the nature of pain perception and experience, as well as the mechanisms underlying these processes, is essential for the development of more effective non-pharmacological pain management strategies. Such a comprehensive understanding will also improve diagnosis and personalize treatment based on the individual psychological characteristics of patients.

In our work, we studied the development of pathological aggression in mice during aggressive experience and its possible reinforcement after deprivation, and also assessed the level of gene expression in the hypothalamus and nucleus accumbens, which may reflect the development of a pathological type of behavior. Male CD1 mice experienced aggression in confrontations with a partner for 30 days, some mice were then kept for another 30 days in the same cages, but without experience of aggressive confrontations (a period of deprivation of aggression). During the experiment (on days 3, 30, and 60), we evaluated aggressive behavior towards a partner and pathological aggression in a test with a juvenile or immobilized male. After a period of deprivation, anxiety levels, plasma corticosterone concentrations, and gene expression in the hypothalamus (Crh, Crhr1, Crhbp, Nr3c1, Fkbp5, Drd1) and nucleus accumbens (Nr3c1, Fkbp5, Drd1, Drd2, Drd3) were assessed. We have found that long-term experience of aggression and subsequent deprivation form several patterns of aggressive behavior in mice: pathological aggressors, non-pathological aggressors, and less aggressive mice. The pathological aggressors demonstrated abnormal aggression towards the immobilized males and increased anxiety after the period of deprivation. At the same time, the experience of aggression did not change the aggressors' corticosterone levels and the expression of glucocorticoid genes in the hypothalamus. We have shown that the hypothalamic-pituitary-adrenal and dopaminergic systems interact in the development of pathological aggression: the expression of the glucocorticoid receptor directly correlates with the expression of the dopamine D1 receptor in the hypothalamus and in the nucleus accumbens. We also found that only the dopamine D1 receptor is involved in the development of pathological behavior, and this occurs region-specifically – its expression was reduced in the hypothalamus and increased in the nucleus accumbens. Together, these results confirm that the mechanisms of the development of pathological aggression are associated with reinforcing effects of this behavior, similar to the mechanisms of addiction.

The development of preventive and therapeutic methods based on the principles of hypoxic conditioning is an urgent task of experimental research, given the high effectiveness of such effects in the prevention and correction of a number of pathological conditions. Previously, we developed hypoxic conditioning regimens using moderate periodic normobaric hypoxia (PNH), created by inhaling low-oxygen gas mixtures. The purpose of this study has been to investigate the behavioral effects of the developed PNH schemes, applied independently, and not as conditioning in pathological models in rats. In the tests (open field, elevated plus-maze and novel object recognition test) there were no significant differences in the behavioral indicators of rats exposed to PNH compared to the indicators of animals in the control group. Thus, the PNH regimens used solely, without pathogenic factors do not affect behavior and can be used for conditioning without the risk of side effects.