Vol 73, No 6 (2023)

Increased oscillatory beta activity in basal ganglia is one of the main electrophysiological biomarkers of impaired motor control in Parkinson’s disease. However, the functional role of dynamical rhythmic processes during movements is still not investigated in detail. We used microelectrode recordings to investigate the subthalamic nucleus neuronal activity in 9 patients with Parkinson’s disease during deep brain stimulation surgery. We have shown that the amplitude of the subthalamic nucleus alpha (7–12 Hz) and low-beta (12–20 Hz) activity correlated with motor impairment indices in patients with Parkinson’s disease. Also, we have shown that, in contrast to beta rhythmic activity, the magnitude of alpha activity decreased significantly during motor tests execution. Moreover, the degree of rhythmic activity suppression in the alpha band correlated with the severity of bradykinesia. These results allow us to suppose that, along with beta activities, subthalamic nucleus neuronal alpha activity also participate in motor control of Parkinson’s disease patients.

The aim of this study was exploring the role of labels in acquisition of information about new objects depending on the learning strategy. In order to reach this aim we investigated efficiency of identification of new objects presented through fast mapping or explicit encoding taking into consideration eye movement patterns. 32 subjects were presented with 8 new fruits 8 times each. The images were accompanied with unique audial labels in 50% of the cases. Visual search of the target image among distractors was used as an assessment task. The results showed that fast mapping speeded learning of information about new objects compared to explicit encoding. We found positive impact of unique labels of new fruits on the results of visual search task. This impact was stronger for fast mapping compared to explicit encoding.

The recovery mechanisms of various forms of behavior upon awakening from sleep are still not well understood. In this work, we investigated the recovery of simple motor reactions to visual stimuli, fine hand-eye coordination, and abstract thinking upon awakening from the deepest, SWS stage of daytime sleep. Subjects were offered two types of tasks: visual-motor tasks in which it was necessary to control a moving object; and arithmetic, in which it was necessary to determine the correctness of the proposed equalities in wakefulness before sleep and during the first 2 minutes of awakening from sleep. The results obtained showed that the speed of a simple motor reaction to the appearance of a visual stimulus reached the wakefulness level almost immediately after awakening (within 4 seconds), while the restoration of the ability to determine the correctness or incorrectness of arithmetic equalities, as well as the ability to accurately control the trajectory of a moving object required much more time: about 40 seconds (in the arithmetic task) and 60 seconds (in the visual-motor task). The power of the alpha-rhythm upon awakening was higher than in wakefulness. Delta-rhythm power was increased only at the beginning of awakening while task performing was difficult, and in the second minute of awakening the delta-rhythm decreased when task performing was restored. Our data indicate that simple and complex forms of behavior upon awakening are not restored simultaneously.

There is a growing body of evidence of memory-enhancing effects of histone deacetylase (HDAC) inhibitors in different species and models. Less clearly is understood whether the increased histone acetylation is able to facilitate the remote fear memory. Thus, the aim of the current study was to examine the ability of HDAC inhibitor sodium butyrate (SB) to ameliorate weakening of the remote fear memory in rats. To assess the ability of HDAC inhibitor SB to improve remote fear memory we compared the performance of two laboratory strains of rats, Wistar and Long-Evans, in context fear conditioning task six months after training before and after the SB administration. We found that the rats showed a strong fear response to the context 24 h after the end of conditioned fear training, full absence of fear after 6 months, and high fear response after the SB administration without additional learning. In control experiments, we found that time-dependent decrease in conditioned fear response to the context was similar in rats under vehicle administration. Moreover, the data obtained showed that both rats’ strains showed a similar decrease in freezing response over time, and HDAC inhibition improved the weak remote fear memory in both of them. In addition, the decrease in freezing and memory reinstatement by males matched completely to the female rats’ performance. These results indicate that HDAC inhibition appears to have the same “rescue” effects on remote fear memory reinstatement regardless of the strain and gender of rats.

Autism, or autism spectrum disorder (ASD), is a multifactorial disease that is characterized not only by disorders of the psycho-emotional state and social interaction, but also by somatic dysfunctions. A number of studies have also reported changes in the musculoskeletal system in patients with ASD. In this work, by the method of video analysis of movements, we demonstrated a decrease in horizontal and vertical motor activity, in addition, deviant movements were recorded, which indicates a violation in locomotor activity and increased anxiety in rats with a valproate model of autism. However, a mechano-myographic study did not reveal significant changes in the contractility parameters of isolated skeletal muscles of rats with the ASD model. Thus, it can be concluded that general differences in movement may be an independent factor in the diagnosis of autism. A more thorough study using a larger sample and detailed kinematic analysis can help in further assessing the variability of motor functions as a potential diagnostic and prognostic marker of ASD.

The development of non-drug methods for correcting stress-induced disorders and improving adaptation to stressful factors remains an urgent task of physiology, which has a great translational potential. Previously, we proposed effective methods of hypoxic hypobaric preconditioning and distant ischemic conditioning in this regard. The purpose of this work was to transfer the principles of preconditioning to the approaches of normobaric intermittent hypoxic training (IHT). The effects of five new IHT regimens (3 five-minute sessions of hypoxia of 16% O₂ per day, 3 sessions of 12% O₂, 7 sessions of 12% O₂, 15 sessions of 12% O₂, 3 sessions of 9% O₂) were studied in experimental models of depression and post-traumatic stress disorder in rats. The preconditioning regime of high intensity 3x9%O₂ had the most pronounced antidepressant and anxiolytic effect in models of both pathologies. With a decrease in the level of hypoxia to 12% O₂, IHT regimens partially retained their effectiveness with an increase in the number of sessions. The training regime of the longest duration – 15 × 12%O₂, was effective in correcting the formation of experimental depression. The intermediate regime – 7 × 12%O₂, had an anxiolytic effect, while the preconditioning regime of medium intensity – 3 × 12%O₂, demonstrated both an antidepressant and anxiolytic effect. The results indicate that the intensity of hypoxic exposure had the greatest impact on the effectiveness. At the same time, a decrease in the intensity to 16% O₂ led to a weakening or loss of stress-protective properties. With regard to the 3 × 9%O₂ regime as the most promising, it is advisable to conduct further studies to identify the molecular mechanisms that implement its stress-protective and anxiolytic effects.

Wizard for EEG Information Tabling – “WEEGIT” is a software designed for visualization and annotation of the long-lasting records of activity. Long-lasting records of raw data are used in various areas of life sciences and well represented in neuroscience. In spite of development of other techniques and approaches the electrophysiological activity registration remains the “golden standard” in neurobiological research. Therefore, we developed and verified “WEEGIT” as a powerful and convenient tool for electrophysiological recordings’ description. We combined the most important features presented in other commercial and noncommercial software in the “WEEGIT”. Presented software can operate with widely used formats of records. ”WEEGIT” allows adaptive visualizing of up to 512 channels of record in different timescale without loss of efficiency and consumption of large machine resources. Visualizing also includes optional built-in temporal-spatial analysis (density of current sources or the density of action potentials) displayed as a background image. Integration of a set of optional filtering and signal transforming procedures allows improving record visualization. “WEEGIT” has a convenient graphical user interface with opportunity of simultaneous time browsing and annotating of the records in one workspace. Annotation can be done by simple text information typing as well as an interactive placing of specialized labels and objects. Software also allows saving data in the resampled format, both for the whole record and for user-defined events. In conclusion, “WEEGIT” provides a great set of benefits for the convenient workflow for beginners and specialists in the electrophysiological area of research, including preparation of the data for further specialized analysis.