Power Of Theta Rhythm Research Articles

Особенности мозговой активности хоккеистов и борцов вольного стиля в задаче по отбиванию шайб в условиях виртуальной реальности

Background. Very scarce works are devoted to the study of hockey players' brain activity, which is connected, among other things, with the large amount of motor activity in athletes and the complexity of EEG registration. Objective. The aim of the study was to investigate electroencephalographic markers (in alpha, beta, and theta EEG bands) during a puck kicking task of varying difficulty under virtual reality conditions in ice hockey players compared to freestyle wrestlers. Methods. The previously developed VR-PACE technology was used for the study, which allows practicing puck reflection skills in hockey in a virtual scene. In the study, pucks were presented in blocks (five blocks in total), the difficulty increased from block 1 to block 4, in block 5 the subjects only observed the pucks. EEG recordings were made using a wireless electroencephalograph BrainScanner V3.1 (research edition) by “NeuroDrive” throughout the entire task, analyzed by 20-second segments in each block and in each of the backgrounds (before and after). Twenty-two male subjects (average age=20, SD=2.4 years) participated in the study. Results. The results showed significant differences between the groups, as well as significant within-group differences between the “before” and “after” conditions of the experiment in terms of the Individual Alpha Frequency (IAF), as well as the average and total power of theta, alpha, and beta rhythms. The overall trend in both groups is similar (after the experiment, there is a decrease in IAF, an increase in alpha rhythm power in central and parietal electrodes, and a decrease in occipital electrodes; a decrease in theta rhythm power in frontal and occipital electrodes; and a decrease in beta rhythm across all electrodes). However, the hockey group exhibits significantly more pronounced shifts in EEG, indicating greater alertness and attention (higher powers of theta, alpha, and beta rhythms both before and after the experiment), as well as greater relaxation (higher power of mu rhythm after the experiment). Conclusions. The study examined the electroencephalographic correlates (IAF, power in the alpha, beta, and theta frequency bands of EEG) in hockey players and freestyle wrestlers while performing a task of deflecting a puck in virtual reality (VR). The dynamics of the EEG indicators indicate more efficient brain function in hockey players when performing the puck reflection task in a virtual reality setting, confirming the hypothesis of neural efficiency.

The defects of the hippocampal ripples and theta rhythm in depression, and the effects of physical exercise on their amelioration

Adverse environmental stress causes depressive symptoms with the impairments of memory formation, cognition, and motivation, however, their underlying neural bases have not been well understood, especially based on the observation of living animals. In the present study, therefore, the mice model of restraint-induced stress was examined electrophysiologically to investigate the alterations of hippocampal sharp wave ripples (SWRs) and theta rhythms. In addition, the therapeutic effects of physical exercise on the amelioration of those hippocampal impairments were examined in combination with a series of behavioral tests. The data demonstrated that chronic restraint stress caused the reductions of occurrence and amplitude of hippocampal SWRs and the decreases of occurrence, duration, and power of theta rhythms, while physical exercise significantly reverted them to the levels of healthy control. Furthermore, hippocampal adult neurogenesis and microglial activation, previously reported to be involved in the etiology of depression, were histologically examined in the mice. The results showed that the impairment of neurogenesis and alleviation of microglial activation were induced in the depressed mice. On the other hand, physical exercise considerably ameliorated those pathological conditions in the affected brain. Consistently, the data of behavioral tests in mice suggested that physical exercise ameliorated the symptomatic defects of motivation, memory formation, and cognition in the depressed mice. The impairments of hippocampal SWRs and theta rhythms in the affected hippocampus are linked with the symptomatic impairments of cognition and motivation, and the defect of memory formation, respectively, in depression. Taken together, this study demonstrated the implications of impairment of the hippocampal SWRs and theta rhythms in the etiology of depression and their usefulness as diagnostic markers of depression.

Psychoemotional state and bioelectrical brain activity in patients of different ages with metabolic syndrome after COVID-19

The aim of this study was to find out the impact of COVID-19 infection on the psycho-emotional state and bioelectrical brain activity in persons of different ages with metabolic syndrome. Material and methods. We examined 53 people who were divided into groups depending on age (40–59 years and 60 years and older) and status with regard to COVID-19 infection (contracted, not contracted). Patients had metabolic syndrome (ATP III), underwent comprehensive clinical and laboratory examinations, electroencephalography (an 18-channel electroencephalograph Nihon Kohden, Japan) and answered the Hospital Anxiety and Depression Scale (HADS) questionnaire. Results. Symptoms of anxiety or depression after COVID-19 were found in both age groups of MS. Anxiety symptoms were more often found in the group of 60 years and older. At the same time, subclinical anxiety was noted in persons of 60 years and older, while clinical anxiety – in middle-aged individuals. The latter also showed a trend towards an increase in clinically evident depression after COVID-19. Persons after COVID-19 with symptoms of anxiety or depression (according to the HADS scale) demonstrated changes in the frequency-amplitude indicators of the electroencephalogram (EEG) characterized by a power increase in the range of theta rhythm and accompanied by subclinical and clinical manifestations of depression. About 80 % of people who did not suffer from COVID-19 had normal EEG since 9 Hz alpha rhythm power was registered. In patients after COVID-19, there was a redistribution of alpha-rhythm power range: an increase in the ranges of alpha-1 rhythm and decrease in alpha-2 rhythm power as well as an increase in the delta and theta rhythm power range. Conclusions. 1–3 months following the acute period of COVID-19, the frequency of depression is 3 times higher in middle-aged patients with metabolic syndrome. In elderly patients with metabolic syndrome after COVID-19, anxiety is predominantly diagnosed – almost in every second. These manifestations of anxiety and depression are accompanied by disorganization of the bioelectrical brain activity.

Enriched environment attenuates hippocampal theta and gamma rhythms dysfunction in chronic cerebral hypoperfusion via improving imbalanced neural afferent levels.

Chronic cerebral hypoperfusion (CCH) is increasingly recognized as a common cognitive impairment-causing mechanism. However, no clinically effective drugs to treat cognitive impairment due to CCH have been identified. An abnormal distribution of neural oscillations was found in the hippocampus of CCH rats. By releasing various neurotransmitters, distinct afferent fibers in the hippocampus influence neuronal oscillations in the hippocampus. Enriched environments (EE) are known to improve cognitive levels by modulating neurotransmitter homeostasis. Using EE as an intervention, we examined the levels of three classical neurotransmitters and the dynamics of neural oscillations in the hippocampus of the CCH rat model. The results showed that EE significantly improved the balance of three classical neurotransmitters (acetylcholine, glutamate, and GABA) in the hippocampus, enhanced the strength of theta and slow-gamma (SG) rhythms, and dramatically improved neural coupling across frequency bands in CCH rats. Furthermore, the expression of the three neurotransmitter vesicular transporters-vesicular acetylcholine transporters (VAChT) and vesicular GABA transporters (VGAT)-was significantly reduced in CCH rats, whereas the expression of vesicular glutamate transporter 1 (VGLUT1) was abnormally elevated. EE partially restored the expression of the three protein levels to maintain the balance of hippocampal afferent neurotransmitters. More importantly, causal mediation analysis showed EE increased the power of theta rhythm by increasing the level of VAChT and VGAT, which then enhanced the phase amplitude coupling of theta-SG and finally led to an improvement in the cognitive level of CCH. These findings shed light on the role of CCH in the disruption of hippocampal afferent neurotransmitter balance and neural oscillations. This study has implications for our knowledge of disease pathways.

Dose and time-dependence of acute intermittent theta-burst stimulation on hippocampus-dependent memory in parkinsonian rats.

The treatment options for cognitive impairments in Parkinson's disease (PD) are limited. Repetitive transcranial magnetic stimulation has been applied in various neurological diseases. However, the effect of intermittent theta-burst stimulation (iTBS) as a more developed repetitive transcranial magnetic stimulation paradigm on cognitive dysfunction in PD remains largely unclear. Our aim was to explore the effect of acute iTBS on hippocampus-dependent memory in PD and the mechanism underlying it. Different blocks of iTBS protocols were applied to unilateral 6-hydroxidopamine-induced parkinsonian rats followed by the behavioral, electrophysiological and immunohistochemical analyses. The object-place recognition and hole-board test were used to assess hippocampus-dependent memory. Sham-iTBS and 1 block-iTBS (300 stimuli) didn't alter hippocampus-dependent memory, hippocampal theta rhythm and the density of c-Fos- and parvalbumin-positive neurons in the hippocampus and medial septum. 3 block-iTBS (900 stimuli) alleviated 6-hydroxidopamine-induced memory impairments, and increased the density of hippocampal c-Fos-positive neurons at 80 min post-stimulation but not 30 min compared to sham-iTBS. Interestingly, 3 block-iTBS first decreased and then increased normalized theta power during a period of 2 h following stimulation. Moreover, 3 block-iTBS decreased the density of parvalbumin-positive neurons in the medial septum at 30 min post-stimulation compared to sham-iTBS. The results indicate that multiple blocks of iTBS elicit dose and time-dependent effects on hippocampus-dependent memory in PD, which may be attributed to changes in c-Fos expression and the power of theta rhythm in the hippocampus.

Alterations in Heart Rate Variability and Electroencephalogram during20‐MinuteExtremely Low Frequency Electric Field Treatment in Healthy Men during theEyes‐OpenCondition

AbstractOur previous study examined the neural effects of extremely low frequency electric field (ELF‐EF) using electroencephalogram (EEG) and heart rate variability (HRV) measurement and revealed that the theta power of EEG increases during 1‐min EF treatment (30 kV and 50 Hz). In the present study, the effects of a longer treatment duration were assessed. EF was applied between two electrodes, one above the head and the other under the feet, for 20 min to 10 healthy men sitting on a chair. Occipital EEG and HRV were measured in the eyes‐open condition. Power spectrum analysis showed that during the EF treatment, the power of alpha and theta rhythms as well as the low frequency component of HRV increased, and the heart rate decreased. These effects did not persist after the end of EF treatment. It is suggested that ELF‐EF treatment alters not only the brain activity but also the autonomic activity reflected in HRV. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Temporal and spatial dynamic propagation of electroencephalogram by combining power spectral and synchronization in childhood absence epilepsy.

ObjectiveDuring the transition from normal to seizure and then to termination, electroencephalography (EEG) signals have complex changes in time-frequency-spatial characteristics. The quantitative analysis of EEG characteristics and the exploration of their dynamic propagation in this paper would help to provide new biomarkers for distinguishing between pre-ictal and inter-ictal states and to better understand the seizure mechanisms.MethodsThirty-three children with absence epilepsy were investigated with EEG signals. Power spectral and synchronization were combined to provide the time-frequency-spatial characteristics of EEG and analyze the spatial distribution and propagation of EEG in the brain with topographic maps. To understand the mechanism of spatial-temporal evolution, we compared inter-ictal, pre-ictal, and ictal states in EEG power spectral and synchronization network and its rhythms in each frequency band.ResultsPower, frequency, and spatial synchronization are all enhanced during the absence seizures to jointly dominate the epilepsy process. We confirmed that a rapid diffusion at the onset accompanied by the frontal region predominance exists. The EEG power rapidly bursts in 2–4 Hz through the whole brain within a few seconds after the onset. This spatiotemporal evolution is associated with spatial diffusion and brain regions interaction, with a similar pattern, increasing first and then decreasing, in both the diffusion of the EEG power and the connectivity of the brain network during the childhood absence epilepsy (CAE) seizures. Compared with the inter-ictal group, we observed increases in power of delta and theta rhythms in the pre-ictal group (P < 0.05). Meanwhile, the synchronization of delta rhythm decreased while that of alpha rhythm enhanced.ConclusionThe initiation and propagation of CAE seizures are related to the abnormal discharge diffusion and the synchronization network. During the seizures, brain activity is completely changed with the main component delta rhythm. Furthermore, this article demonstrated for the first time that alpha inhibition, which is consistent with the brain’s feedback regulation mechanism, is caused by the enhancement of the network connection. Temporal and spatial evolution of EEG is of great significance for the transmission mechanism, clinical diagnosis and automatic detection of absence epilepsy seizures.

Increased spectral power of theta rhythm is not associated with decreased supragranular thickness in first-episode schizophrenia

IntroductionSchizophrenia is associated with disturbances in neurophysiological processes. However, the relation of EEG and ERP parameters to structural supragranular cortical abnormalities, observed in schizophrenia, remains unclear.ObjectivesThe purpose was to characterize EEG and ERP disturbances and their relationship to changes occurring in supragranular cortical layers in subjects with schizophrenia.Methods43 first-episode schizophrenia (FES) male patients and 43 matched healthy controls (HC) underwent background EEG and standard two-tones oddball ERP recording and structural MRI at 3T Philips scanner. MRI images were processed via FreeSurfer and MATLAB to derive two markers specific to supragranular thickness change: gyral-sulcal thickness differences (GSTD) and gyral-sulcal intrinsic curvature differences on pial surface (GSCD) (github.com/kwagstyl/schizophrenia_gyral_sulcal).ResultsTheta rhythm spectral power was increased in FES while P300 amplitudes and latencies, N100 (to non-targets) amplitudes, alpha rhythm spectral power were not altered compared to HC. GSCD measures were increased in temporal, parietal and occipital cortices, whereas both GSTD and GSCD were increased in the right frontal cortex in FES. No correlations between altered EEG and supragranular thickness markers survived correction for multiple comparisons.ConclusionsPresumably, theta rhythm has a widespread circuit of generators, including the cortical ones. However, we have not found correlations between EEG and supragranular markers in FES. Considering an absence of correlations between theta and hippocampal volumes (Lebedeva et al., 2020), a speculative interpretation is that the neurophysiological disturbances may be associated with a more complex patterns of more localized structural and functional impairments.DisclosureThe work was supported by RFBR grant 20-013-00748.

Myelination synchronizes cortical oscillations by consolidating parvalbumin-mediated phasic inhibition.

Parvalbumin-positive (PV+) γ-aminobutyric acid (GABA) interneurons are critically involved in producing rapid network oscillations and cortical microcircuit computations, but the significance of PV+ axon myelination to the temporal features of inhibition remains elusive. Here, using toxic and genetic mouse models of demyelination and dysmyelination, respectively, we find that loss of compact myelin reduces PV+ interneuron presynaptic terminals and increases failures, and the weak phasic inhibition of pyramidal neurons abolishes optogenetically driven gamma oscillations in vivo. Strikingly, during behaviors of quiet wakefulness selectively theta rhythms are amplified and accompanied by highly synchronized interictal epileptic discharges. In support of a causal role of impaired PV-mediated inhibition, optogenetic activation of myelin-deficient PV+ interneurons attenuated the power of slow theta rhythms and limited interictal spike occurrence. Thus, myelination of PV axons is required to consolidate fast inhibition of pyramidal neurons and enable behavioral state-dependent modulation of local circuit synchronization.

Antiseizure Effects of Fully Characterized Non-Psychoactive Cannabis sativa L. Extracts in the Repeated 6-Hz Corneal Stimulation Test.

Compounds present in Cannabis sativa L. preparations have recently attracted much attention in the treatment of drug-resistant epilepsy. Here, we screened two olive oil extracts from a non-psychoactive C. sativa variety, fully characterized by high-performance liquid chromatography and gas chromatography. Particularly, hemp oils with different concentrations of terpenes were administered at the same dose of cannabidiol (25 mg/kg/day orally), 1 h before the 6-Hz corneal stimulation test (44 mA). Mice were stimulated once a day for 5 days and evaluated by video-electrocorticographic recordings and behavioral analysis. Neuronal activation was assessed by FosB/ΔFosB immunoreactivity. Both oils significantly reduced the percentage of mice experiencing convulsive seizures in comparison to olive oil-treated mice (p < 0.050; Fisher’s exact test), but only the oil enriched with terpenes (K2) significantly accelerated full recovery from the seizure. These effects occurred in the presence of reduced power of delta rhythm, and, instead, increased power of theta rhythm, along with a lower FosB/ΔFosB expression in the subiculum (p < 0.050; Duncan’s method). The overall findings suggest that both cannabinoids and terpenes in oil extracts should be considered as potential therapeutic agents against epileptic seizures and epilepsy.

Neuropsychological features of patients of reproductive age diagnosed with breast cancer at the stage of surgical treatment using xenon-oxygen therapy

Purpose of the study. To study functional changes in the neuropsychological status of reproductive age patients with newly diagnosed breast cancer and to assess the possibility of using xenon-oxygen therapy to correct disorders.Patients and methods. This study included 60 reproductive age patients with newly diagnosed breast cancer who were undergoing surgical treatment at the Department of Bone, Skin, Soft Tissue and Breast Tumors of the National Medical Research Centre for Oncology of the Ministry of Health of Russia from 2018 to 2020. The main group included 30 patients with breast cancer diagnosed at the surgical stage of combined treatment, who underwent a rehabilitation course of xenon-oxygen therapy in the early postoperative period. The control group was formed from patients with the same diagnosis, without the use of this therapy. The functional state of the central nervous system in all patients was assessed by the parameters of the electroencephalography (EEG) bioelectrical activity. For the final assessment of the physiological and psychological state of the patients, a standardized questionnaires of the quality of life – ESAS, MOS-SF‑36, were used. Statistical data processing was performed using the Statistica 10 software package. Results. During the study, statistically significant differences were found in the assessment of subjective indicators, so in the group of patients using xenon-oxygen therapy, there was an improvement in well-being by 2.6 times, a decrease in depression by 2.3 times, a decrease in symptoms of nausea by 3 times, anxiety 1.9 times (p &lt; 0.05). Against the background of an improvement in the psychophysiological state, the EEG showed a significant increase in the power of slow delta and theta rhythms, an increase in the power of the alpha rhythm and a decrease in the power of the beta rhythm, while in the patients of the control group only a decrease in the power of the beta rhythm was noted.Conclusion. The early postoperative period in patients with newly diagnosed breast cancer is characterized by the formation of a depressive symptom complex. The use of a course of xenon-oxygen therapy contributes to the normalization of the subjective feeling of physical and psychological health, increasing vital and social activity. Changes in the indicators of brain bioelectric activity and an improvement in psychophysiological state occur against the background of changes in brain activity caused by the normalizing effect of xenon.

Altered Emotional Phenotypes in Chronic Kidney Disease Following 5/6 Nephrectomy.

Increased prevalence of chronic kidney disease (CKD) and neurological disorders including cerebrovascular disease, cognitive impairment, peripheral neuropathy, and dysfunction of central nervous system have been reported during the natural history of CKD. Psychological distress and depression are serious concerns in patients with CKD. However, the relevance of CKD due to decline in renal function and the pathophysiology of emotional deterioration is not clear. Male Sprague Dawley rats were divided into three groups: sham control, 5/6 nephrectomy at 4 weeks, and 5/6 nephrectomy at 10 weeks. Behavior tests, local field potentials, and histology and laboratory tests were conducted and investigated. We provided direct evidence showing that CKD rat models exhibited anxiogenic behaviors and depression-like phenotypes, along with altered hippocampal neural oscillations at 1–12 Hz. We generated CKD rat models by performing 5/6 nephrectomy, and identified higher level of serum creatinine and blood urea nitrogen (BUN) in CKD rats than in wild-type, depending on time. In addition, the level of α-smooth muscle actin (α-SMA) and collagen I for renal tissue was markedly elevated, with worsening fibrosis due to renal failures. The level of anxiety and depression-like behaviors increased in the 10-week CKD rat models compared with the 4-week rat models. In the recording of local field potentials, the power of delta (1–4 Hz), theta (4–7 Hz), and alpha rhythm (7–12 Hz) was significantly increased in the hippocampus of CKD rats compared with wild-type rats. Together, our findings indicated that anxiogenic behaviors and depression can be induced by CKD, and these abnormal symptoms can be worsened as the onset of CKD was prolonged. In conclusion, our results show that the hippocampus is vulnerable to uremia.

Evaluating users’ preference for the appearance of humanoid robots via event-related potentials and spectral perturbations

ABSTRACT Even though humanoid robots are being applied to diverse areas, the formation of users’ preference for the appearance of humanoid robots remains unknown. The present study investigated users’ neural dynamics underlying preference formation to evaluate users’ preference for the appearance of humanoid robots. EEG signals were recorded in a preference categorisation task, and neural dynamics were analysed via event-related potentials and time–frequency analysis. The results showed that in the early stage, the preferred humanoid robot appearances elicited enhanced parieto-occipital N1, frontal P2, and early central and parieto-occipital theta rhythm power than the non-preferred appearances. In the later stage, the preferred humanoid robot appearances elicited enhanced scalp-distributed LPP and later central and parieto-occipital theta power than the non-preferred appearances. The results suggested that the formation of users’ preference for the appearance of humanoid robots has a distinctive dual-stage of neural dynamics. The study provides designers with an objective method in evaluating users’ preference for the appearance of humanoid robots.

VEGF Modulates the Neural Dynamics of Hippocampal Subregions in Chronic Global Cerebral Ischemia Rats.

Theta and gamma rhythms in hippocampus are important to cognitive performance. The cognitive impairments following cerebral ischemia is linked with the dysfunction of theta and gamma oscillations. As the primary mechanism for learning and memory, synaptic plasticity is in connection with these neural oscillations. Although vascular endothelial growth factor (VEGF) is thought to protect synaptic function in the ischemia rats to relieve cognitive impairment, little has been done on its effect of neural dynamics with this process. The present study investigated whether the alternation of neural oscillations in the hippocampus of ischemia rats is one of the potential neuroprotective mechanisms of VEGF. Rats were treated with the intranasal administration of VEGF at 72h following chronic global cerebral ischemia procedure. Then local field potentials (LFPs) in hippocampal CA1 and CA3 regions were recorded and analyzed. Our results showed that VEGF can improve the power of theta and gamma rhythms in CA1 region after ischemia. Chronic global cerebral ischemia reduced the theta-gamma phase-amplitude coupling (PAC) not only within CA1 area but also in the pathway from CA3 to CA1, while VEGF alleviated the decreased coupling strength. Despite these notable differences, there were no obvious changes in the PAC within CA3 region. Surprisingly, the ischemia state did not affect the phase-phase interaction of hippocampus. In conclusion, our findings demonstrated that VEGF enhanced the theta-gamma PAC strength of CA3-CA1 pathway in ischemia rats, which may futher improve the information transmission within the hippocampus. These results illustrated the potential electrophysiologic mechanism of VEGF on cognitive improvement.

НЕЙРОФИЗИОЛОГИЧЕСКИЕ МЕХАНИЗМЫ ВОСПРИЯТИЯ РЕЧИ И ИХ ОСОБЕННОСТИ У ДЕТЕЙ В НОРМЕ И ПРИ НАРУШЕНИЯХ РАЗВИТИЯ

Neuronal synchronization, reflected in the EEG pattern, is the mechanism by which the brain integrates different types of information contained in a speech message and presented in different areas of the brain (for example, phonological, spelling, semantic and syntactic information). The process of understanding a sentence consists of two groups of interrelated cognitive operations: it begins with searching in memory for phonological, syntactic and semantic properties of words, which is followed by integrating information into a general idea of the sentence meaning. The stage of searching for words in adults results in an increase in the theta rhythm power. The stage of integrating words into a sentence results in the growth of theta, beta, and gamma rhythms. At the same time, the growth of theta rhythm is more typical for children than for adults. Higher rhythms reactivity during speech perception indicates better developed speech skills in children. Under conditions of relative relaxation, the EEG of children with a high level of speech development is characterized by a moderate power level of theta and beta rhythms and a high level of alpha and mu rhythms. It is assumed that a key role in the process of understanding speech is played by the so-called «action perception circuits», surrounding the Sylvian sulcus of the left hemisphere. The «action perception circuits» are composed of nerve cells capable of providing the speech signals perception and generation. The most important subgroup of neurons included in the «action perception circuits» are mirror neurons that are activated when performing and observing actions. The desynchronization of the EEG mu rhythm is considered as mirror neurons activation marker. In several studies, it revealed that the level of mirror neurons activation and the level of speech understanding in children are connected. It is a topic of great interest to research the mu rhythm alpha and beta components reactivity both during the production of speech and during the perception of another person speech. At present, it is becoming obvious that analyzing the EEG rhythms power changes during the speech understanding in different scenarios could be used to identify the mechanisms of the brain language network and speech disorders. The revealed patterns make it possible to propose ways of correcting the children speech development using EEG biological feedback methods.

The role of functional brain activity in the impairment of inhibitory control in alcohol dependence

Determination of differences in brain function in alcohol-dependent patients with varying degrees of inhibitory control impairment.Seventy-five patients with alcohol dependence were examined. The level of inhibitory control was assessed using the Go/No-go test. The background electric activity of the brain was recorded, and the values of spectral power and coherence of theta, alpha, and beta rhythms were analyzed. Two groups of patients - 24 with- and 51 without inhibitory control impairment - were determined.According to the spectral analysis, high values of alpha rhythm in the frontal-central-parietal-occipital and beta rhythm in the central and left occipital cortex, low values of theta rhythm in the posterior-temporal regions were common for patients with inhibitory control impairment. Visual analysis of the EEG in patients with inhibitory control impairment shows a smoothing of zonal differences in the alpha rhythm, which is not found in patients without the disturbance of inhibitory control. Patients with inhibitory control impairment were characterized by an increase in interhemispheric connections in the alpha and beta frequency ranges and a weakening of intrahemispheric connections on the right in the theta rhythm range.There are significant differences in the functioning of the brain in patients with alcoholism, depending on the presence / absence of inhibitory control impairment.Определение различий в функционировании головного мозга у больных алкогольной зависимостью с разной степенью нарушения ингибиторного контроля.Обследованы 75 пациентов с алкогольной зависимостью. Оценка уровня ингибиторного контроля проводилась с помощью теста Go/No-go. Проводилась запись фоновой биоэлектрической активности головного мозга, анализировались значения спектральной мощности и когерентности тета-, альфа- и бета-ритмов. Выделено две группы пациентов: 1-я группа (n=24) — без нарушения ингибиторного контроля, 2-я группа (n=51) — с дефицитом ингибиторного контроля.По данным спектрального анализа общим признаком для пациентов с дефицитом ингибиторного контроля были отмечены высокие значения альфа-ритма в лобно-центро-теменно-затылочных и бета-ритма в центральных и левом затылочном отделах коры головного мозга, низкие значения тета-ритма в задневисочных отделах. При визуальном анализе ЭЭГ у пациентов с дефицитом ингибиторного контроля отмечается сглаживание зональных различий альфа-ритма, чего не обнаруживается у пациентов без нарушения ингибиторного контроля. Обнаружено, что для пациентов с дефицитом ингибиторного контроля было характерно усиление межполушарных связей в диапазонах альфа- и бета-частот и ослабление внутриполушарных связей справа в диапазоне тета-ритма.Проведенное исследование показало, что существуют значимые различия в функционировании головного мозга у пациентов с алкоголизмом в зависимости от наличия/отсутствия нарушения (дефицита) ингибиторного контроля.

Long-Term Neurophysiological Outcomes in Patients Undergoing Coronary Artery Bypass Grafting.

IntroductionThis study aims to evaluate late postoperative neurophysiological outcomes in patients after coronary artery bypass grafting (CABG).MethodsForty-five male patients with stable coronary artery disease aged 45-69 years underwent extended neuropsychological assessment using the software Status PF and electroencephalographical examination 3-5 days before CABG and 5-7 years after CABG. Postoperative decline in cognitive functions was determined by a 20% decrease in the cognitive indicator compared to that at baseline on 20% of the tests included in the Status PF battery. Statistical analysis was performed using the software STATISTICA 10.0. Multiple regression was used to identify demographic, clinical, and electroencephalographical variables associated with adverse cognitive outcomes.ResultsCognitive decline was observed in 54% of the patients in the long-term postoperative period. Five to seven years after CABG, all patients have shown an increase in the theta rhythm power compared to the preoperative values, which is most pronounced in the frontal and temporal areas of the right hemisphere (P=0.04), along with a decrease in the alpha rhythm in the posterior areas of the cortex (P=0.005). Multiple regression has reported that the main predictors of cognitive impairment are slower mean alpha frequency, decreased theta-2 rhythm with eyes closed in the right temporal area, and increased theta-2 rhythm with eyes open in the left temporal area (F(5.39)=8.81; P<0.00007; adjusted R-squared=0.57).ConclusionOur findings indicate that 54% of the patients suffer from postoperative cognitive decline associated with increased theta and decreased alpha rhythms 5-7 years after CABG.

Relationship of background electroencephalogram with cognitive impairment in patients with alcohol dependence

A significant number of studies have focused on the neurophysiological basis of cognitive dysfunction among individuals with neurological and psychiatric disorders, including alcoholism. However, the neural correlates of cognitive deficits in alcohol dependence are still not clear enough.&#x0D; The purposeof the study: to identify the relationship of background electroencephalogram indicators with cognitive disorders in patients with alcohol dependence.&#x0D; Material and methods.107patients with alcohol dependence aged 30 to 60years after detoxification were examined. The background electroencephalogram was recorded with closed eyes for 2min. The values of the absolute spectral power of theta, alpha and beta rhythms were analyzed. The study of the level of Executive functioning was conducted using the Go/Nogo test. The level of spatially working memory was evaluated using the Corsi Block-Tapping test.&#x0D; Results.Data analysis revealed statistically significant correlations between the spectral power of the alpha rhythm in the occipital cortex and the number of errors per inhibitory signal (Nogo) in the Go/Nogo problem (r=0.287; p=0.025). There were also statistically significant correlations between the values of alpha-rhythm spectral power and working memory in the Corsi test in the parietal cortex (r=0.273; p=0.037), occipital cortex (r=0.316; p=0.015) and temporal cortex (r=0.359; p=0.005). There were no statistically significant correlations of beta and theta rhythms with the results of cognitive tests (p0.05).&#x0D; Conclusion.Thus, all of the above results indicate that the background EEG indicators, in particular the spectral power of alpha activity, can with a certain probability indicate violations of cognitive functioning (inhibitory control and working memory) in patients with alcohol dependence.

Brain Oscillatory Activity during Tactile Stimulation Correlates with Cortical Thickness of Intact Areas and Predicts Outcome in Post-Traumatic Comatose Patients.

In this study, we have reported a correlation between structural brain changes and electroencephalography (EEG) in response to tactile stimulation in ten comatose patients after severe traumatic brain injury (TBI). Structural morphometry showed a decrease in whole-brain cortical thickness, cortical gray matter volume, and subcortical structures in ten comatose patients compared to fifteen healthy controls. The observed decrease in gray matter volume indicated brain atrophy in coma patients induced by TBI. In resting-state EEG, the power of slow-wave activity was significantly higher (2–6 Hz), and the power of alpha and beta rhythms was lower in coma patients than in controls. During tactile stimulation, coma patients’ theta rhythm power significantly decreased compared to that in the resting state. This decrease was not observed in the control group and correlated positively with better coma outcome and the volume of whole-brain gray matter, the right putamen, and the insula. It correlated negatively with the volume of damaged brain tissue. During tactile stimulation, an increase in beta rhythm power correlated with the thickness of patients’ somatosensory cortex. Our results showed that slow-wave desynchronization, as a nonspecific response to tactile stimulation, may serve as a sensitive index of coma outcome and morphometric changes after brain injury.

A potential entanglement between the spinal cord and hippocampus: Theta rhythm correlates with neurogenesis deficiency following spinal cord injury in male rats.

Cognitive deficits due to spinal cord injury (SCI) have been elucidated in both animals and humans with SCI. Such disorders may cause concomitant oscillatory changes in regions of the brain involving in cognition; a subject that has not been directed mechanistically. One of the crucial oscillations, having a prominent role in cognition, particularly spatial memory, is hippocampal theta rhythm. Our research revealed that SCI could induce changes not only in the neurogenesis and apoptosis rate of the hippocampus but also in theta power as well as receptors involving in the generation of this rhythm. Herein we used 24 male Wistar rats (Sham/SCI=12) and examined the effect of spinal cord contusion on hippocampal theta rhythm, spatial memory, and neurodegeneration. We proved that SCI eliminates hippocampus-dependent theta power through spatial working memory, and correlates significantly with neurodegeneration and expression of receptors (NMDA, GABAA, Muscarinic1/M1), which are in turn essential in generation of theta rhythm. The immunohistochemistry analysis also demonstrated a significant decrease in DCX+ and BrdU+ cells; however, according to TUNEL assay, apoptosis is significantly higher in SCI-induced animals. The western blotting analysis further showed a significant reduction of the abovementioned receptors in the hippocampus. We also verified that SCI impairs the spatial memory, proved by poor performance in the Y-maze task. As well as, based on the local field potential recordings analysis, SCI decreases the power of theta rhythm. Eventually, this study demonstrated that chronic brain neurodegeneration occurs after SCI accompanied by theta rhythm and cognitive deficiency.