Rossiiskii fiziologicheskii zhurnal imeni I.M. Sechenova最新文献

In behavioral experiments rhesus macaque monkeys were trained to interact with the computer using a tactile display. We used grayscale Gabor patches of low spatial frequency as stimuli. Monkeys' task was to touch the screen with his hand in the area of the target stimulus, followed by automatic food or juice reinforcement. After two successive correct answers, stimulus contrast gradually decreased. Using a two-alternative forced choice method the contrast threshold was measured within which monkeys can detect the appearance of low-frequency images. It was shown that the contrast sensitivity decreased with the decrease of stimulus spatial frequency, while the reaction time increased. The findings extend our knowledge of the primates' activity in the virtual environment and open new possibilities for modeling and studying various human diseases.

In the study, distinctions in daily timecourse of spectral parameters of the heart rate variability (HRV) at rest wakefulness and at information load in students with different chronotypes are revealed. The most pronounced changes in the general spectral power of HRV due to fluctuations of all parameters, but especially the VLF, LF, HF waves and the LF/HF index were found in students with a daily chronotype at rest and after implementation of load tests during the different periods of the school day. In persons with an evening chronotype in conditions of rest, the greatest variability was found in a spectral HF component of HRV, and responses to information load were found during the day in different combinations of changes of LF and HF components and the LF/HF index. In students with a morning chronotype during rest wakefulness, considerable fluctuations of a proportion of LF waves were observed, whereas in response to information load during certain periods of the day, representation of LF and HF components of the spectrum was changed. The wide variability of HRV spectral parameters in students with daily activity, compared to students with early and late activities, reflects the advantages of persons with a daily chronotype in terms of adaptation to different operation modes and irregular stress information in the course of the day.

The multimodal influence of the auditory motion adaptation was studied until now on visual perception only, however, the auditory motion adaptation can influence other modalities. This study is the first attempt to investigate postural aftereffects to 45-second adaptation to approaching or withdrawing sound images, that were simulated by rhythmic sequences of tone pulses changed linearly in amplitude and frequency in the free field. The oscillations of the center of pressure in the sagittal plane with the rhythm of stimuli were detected. These oscillations were more noticeable for approaching than for withdrawing stimuli and resulted in an increase of the length of the trajectory of the center of pressure and average linear velocity of its motion. The center of pressure shifted in the direction of the sound motion during listening to approaching sound images, and to the opposite direction during 20 s after its turning off. The shift to the opposite direction demonstrates typical negative aftereffect. The data are in accordance with the results of studies of postural responses to moving visual stimuli, where the «negative» effect was also revealed.

The specificity of motor systems and its influences on effectiveness of modeling purposeful activity in 46 healthy people and 110 patients with epilepsy was studied. Using cluster analysis the patients with epilepsy were divided in 2 groups: high- and low efficient. The differences of physiological parameters, which characterize the activity of central level of motor systems and visual-motor reaction, were determined. The high level of activation of cortical mechanisms of decision-making and preparedness to motor reaction in the group of healthy people and low effectiveness associated with insufficient activation of these mechanisms in the group of patients with epilepsy was described.

Six (6) mongrel dogs at the age of six (6) months underwent transphyseal elastic intramedullary osteosynthesis for tibial shaft fracture. Clinical, X-ray, and physiological methods were used. As determined, the transphyseal reinforcement of the injured bone doesn't influence the lib function, but it retards the segment longitudinal growth. The eccentric arrangement of rods leads to forming angular deformity of the articular surface. Changes occur in the temperature of the covering tissues of the lateral tibial condyle. Consolidation period of the bone fragments is not increased. The union is formed through the blood flow of hypokinetic type in soft tissues. When intramedullary elastic rods being inserted the endosteal and periosteal response contributes to increasing the thickness of bone cortical plates and diameter.

The ability of muscle cells to respond to certain signaling molecules depends on the presence of specific proteins-receptors, ion channels and transporters, which create a system of metabolic inputs. All cells in the human body have a transmembrane signaling system that allows to get information from extracellular stimuli such as hormones, neurotransmitters, proteins, peptides, derivatives of amino acids and fat acids, sensor molecules. The results of researches published in the last two years, which expand knowledge of action of various factors on protein metabolism in skeletal muscles are presented in the review. The main attention is turned to the discovery and expansion of signaling pathways involved in the regulation of protein metabolism in skeletal muscle in different functional states of the person.

It was established that chronic unpredictable stress, which was reproduced by repeated exposure of adverse factors on the pregnant rats (food deprivations during one day, immobilization in the water of room temperature and contact with Felis excrements) results in the stable and sex-specific offspring's behavioural changes in the «open field» test, disorders of motor and coordinator functions and the increased sensitivity to pain at the age of both 1 and 3 months. Male and female rats, which were exposed to the prenatal stress, demonstrate elevated blood pressure. Enhanced lipoperoxidation in the blood serum of male rats after prenatal stress was indicated. Thus, prenatal stress leads to the stable alteration of the reactivity, which may favour persistent social maladjustment and the development of different pathologies.

In the last years it was shown that autoantibodies to the extracellular regions of the ionotropic receptors, such as glutamate AMPA- and NMDA-receptors, GABAA-receptors, glycine and nicotinic acetylcholine receptors, induce a wide spectrum of autoimmune diseases, including limbic encephalitis, Rasmussen's encephalitis, systemic lupus erythematosus, myasthenia gravis, encephalomyelitis, and stiff-man syndrome. In the review the literature data concerning the autoimmune processes provoking autoantibodies formation to the ionotropic receptors, the epitopes participating in the induction of pathogenic autoantibodies, and the effects of these antibodies on the functions of nervous cells and their role in the development of autoimmune diseases were analyzed and systematized. The possible role of oncology diseases in the generation of autoantibodies to the ionotropic receptors was discussed. Approaches that are currently being developed to inhibit the synthesis of pathogenic autoantibodies and to their neutralization were considered. These approaches may be subsequently used to treat the autoimmune diseases caused by the antibodies to ionotropic receptors.

In the experiments carried out on the isolated by Langendorff's method hearts which were perfused at the constant coronary flow it was studied influence of iNOS-derived NO on the functional activity of the KATP-channels in the coronary vascular smooth muscle cells following formation of the adaptation to the stress. As an adaptation to the short stress as a 6-hours immobilization stress result in increase of NO production and rise of expression of gene iNOS; however, adaptation in contrast to the stress leads to moderate accumulation of iNOS against the background unchanged systemic activity of еNOS and in the absence of systemic low-grade inflammation. After an adaptation to the short stress or after 6 hours of immobilization the functional glybenclamid-inhibiting activity of the KATP-channels was suppressed. Nevertheless, after prolonged immobilization suppressed activity of the channels was abolished after blockage of iNOS, whereas iNOS blockage in adapted animals leads not only to the recovery but even to the hyperactivation of the KATP-channels. Hence, increase in NO production which is typical for the adaptation, limits activation of the KATP-channels thus creating a strong link between these channels activity and NO produced by iNOS.

Changes in the metabolism of female rats hanging by cervical dorsal skin fold within 24 hours were examined. It was found that stress exposure results in an increase of the concentration of the final nitric oxide metabolites in the blood serum and homogenates of the heart and brain of animals, intensification of processes peroxidation lipids and mitochondrial dysfunction in these organs. Thus increase of mean arterial blood pressure by 18.9 % from baseline and violation of platelet and plasma components of hemostasis. Inhibitor of neuronal NO-synthase 7-nitroindazole in the dose of 50 mg/kg aggravates of the studied parameters changes. Administration of an animal selective inhibitor of inducible NOS aminoguanidine (50 mg / kg) contributes to limiting the damaging effects of stress reaction.