Cerebral Activity Research Articles

Hyperscanning: from inter-brain coupling to causality

In hyperscanning studies, participants perform a joint task while their brain activation is simultaneously recorded. Evidence of inter-brain coupling is examined, in these studies, as a predictor of behavioral change. While the field of hyperscanning has made significant strides in unraveling the associations between inter-brain coupling and changes in social interactions, drawing causal conclusions between brain and behavior remains challenging. This difficulty arises from factors like the inherently different timescales of behavioral responses and measured cerebral activity, as well as the predominant focus of existing methods on associations rather than causality. Specifically, a question remains as to whether inter-brain coupling between specific brain regions leads to changes in behavioral synchrony, or vice-versa. We propose two novel approaches to addressing this question. The first method involves using dyadic neurofeedback, wherein instances of inter-brain coupling are directly reinforced. Such a system could examine if continuous changes of inter-brain coupling are the result of deliberate mutual attempts to synchronize. The second method employs statistical approaches, including Granger causality and Structural Equation Modeling (SEM). Granger causality assesses the predictive influence of one time series on another, enabling the identification of directional neural interactions that drive behavior. SEM allows for detailed modeling of both direct and indirect effects of inter-brain coupling on behavior. We provide an example of data analysis with the SEM approach, discuss the advantages and limitations of each approach and posit that applying these approaches could provide significant insights into how inter-brain coupling supports crucial processes that occur in social interactions.

The effectiveness of cryostimulation exposure on sleep and recovery in male athletes: Timing considerations.

The objectives of the study were (i) to evaluate the effects of whole-body cryostimulation (WBC) after training as an effective tool to improve sleep and recovery and (ii) to determine which exposure schedule for WBC (immediately after training vs. 1h before bedtime) is the most appropriate to improve sleep and recovery. Twenty-two well-trained male athletes or triathletes (23.1±3.5-years) were recruited in this controlled crossover protocol. Each participant completed the three experimental sessions, each composed of a running training session and one night of sleep analysis. Depending on the experimental condition, subjects were exposed-or not (CONT)-to WBC immediately after training (CRYO 7 p.m.) or 1h before going to bed (CRYO 10 p.m.). All participants were randomly assigned to each condition, spaced seven days apart. Sleep was monitored via actimetry, cerebral activity recordings, heart rate variability, body core temperature, and perceptual measurements. WBC after training did not modify subjective or objective sleep parameters compared to the control condition. However, WBC significantly improved cardiac parasympathetic activity. More specifically, it was more activated during the night following the CRYO 10 p.m. condition than in the other experimental conditions. Core body temperature (CBT) 1h after bedtime was the lowest in the CRYO 10 p.m. condition. This study confirmed the effectiveness of WBC as a recovery technique after intense evening training. We suggest that WBC may exhibit the most significant benefit on recovery if the session is performed 1h before bedtime, acting on subsequent parasympathetic activation and CBT drop.

Dysfunctional activation of the default mode network in response inhibition in schizophrenia

The aim of this study was to characterize dysfunctional cerebral activation in patients with schizophrenia while they performed a response inhibition task. To achieve this, performance on the task and functional magnetic resonance imaging (fMRI) were compared between healthy control subjects (HC) and patients with schizophrenia (SZ). We focused on the default mode network (DMN), as there is strong evidence in the literature that lack of DMN suppression in schizophrenia is associated with cognitive impairment including poor response inhibition. fMRI was used to measure blood-oxygen-level-dependent activation in 84 subjects (44 SZ and 40 HC) while they performed a Go NoGo task. The subjects were also evaluated for psychiatric symptoms and immediate visual memory.SZ performed more poorly than HC on the task; they had a higher number of commission errors. On the fMRI, the patients consistently evidenced higher activation than the controls in several areas of the default mode network (DMN) including the precuneus, rostral anterior cingulate, parahippocampus and insula. The higher brain activation in the patients with schizophrenia indicates a failure to deactivate the DMN while they perform the response inhibition task. These findings point to the importance of DMN dysfunction as an underlying cause of impairment in response inhibition in schizophrenia. DMN disruptions play an essential role in the cognitive impairment present in schizophrenia.

The Impact of Sports Participation on College Students' Learning Outcomes: A Mixed Methods Study based on Multiple Campuses

Plato said: In order for humans to have a successful life, God provides two channels-education and sports. We are increasingly seeing that these two channels are complementary and indispensable. Modern neuroscience research shows that sports can have beneficial effects on brain structure and function, epigenetic regulation of brain tissue, cerebral cortex activity patterns and learning-related psychological factors, thereby improving students' cognitive abilities and academic performance. This study aims to explore the multifaceted effects of sports participation on college students' learning outcomes. A mixed research method was used to collect data in three different types of universities, including a questionnaire survey of 500 students and in-depth interviews with 20 students and 10 faculty members. Quantitative analysis showed that moderate sports participation was significantly related to better academic performance, higher mental health and stronger time management skills. However, excessive participation in physical activities may have a negative impact on study time. Qualitative data further revealed how sport participation enhanced students' self-confidence, teamwork and stress management skills. The study also found that the impact of sports participation varies depending on students' personal backgrounds and the characteristics of their universities. Based on the research results, this article puts forward practical suggestions to promote the balanced development of college students, providing a basis for higher education institutions to formulate relevant policies.

Estimation of Interferences in Magnetoencephalography (MEG) Brain Data Using Intelligent Methods for BCI-based Neurorehabilitation Applications

<p>Brain-Computer Interface (BCI) neurorehabilitation offers the potential to improve recovery and quality of life for stroke survivors. It aims to restore lost physical and mental abilities through motor and cognitive therapies. Magnetoencephalography (MEG) signals are a major advancement in BCI technology as they provide accurate and consistent assessments of brain activity for control and interaction applications. MEG is indispensable for recording the magnetic fields produced in the brain during motor imagery tasks due to its capability to evaluate cerebral activity with remarkable temporal resolution. However, one of the major challenges associated with MEG recording is the loss of signal quality due to physiological artifacts and ambient noise. Additionally, the head movement of the individual during the recording process can result in the introduction of artifacts into the recorded data, which can distort the spatial mapping of brain activity. This, in turn, can jeopardize the reliability and accuracy of the results obtained. This study aims to identify the most effective technique for removing artifacts from MEG signals by conducting a comparative performance analysis of prominent denoising algorithms, such as Infomax, FastICA, SOBI, and SWT. The findings conclude that Infomax is the most effective algorithm for removing physiological artifacts from a signal while maintaining the integrity and essential features of the original data. FastICA was found to be the second most effective algorithm. Infomax outperformed FastICA in Power Spectral Density (PSD) and Percentage Root mean square error Difference (PRD) measurements.</p>

A Novel Preclinical Murine Model of Systemic Lupus Erythematosus-Like Cardiovascular Disease.

Systemic lupus erythematosus (SLE) affects nine women to every man worldwide, and these patients are at greater risk for cardiovascular disease (CVD) morbidity and mortality. Clinical studies have demonstrated that patients with SLE are more likely to develop CVD, including cardiac and vascular dysfunction. Although many preclinical models of SLE are available, including treatment with Toll-like receptor (TLR) 7/8 agonists, a consistent preclinical model of SLE-like CVD with systemic, cardiac, renal, and cerebral endothelial activation and cardiac dysfunction has yet to be described. Here, we hypothesize that acceleration of SLE with the TLR7/8 agonist resiquimod (R848) will promote cardiac and endothelial activation with subsequent end-stage organ damage in the SLE-prone B6.Nba2 mouse model. Female and male SLE-prone B6.Nba2 mice were treated with R848 or acetone, administered topically twice weekly over a four-week period, to accelerate the development of SLE-like pathophysiology. Echocardiography was performed at baseline, 4 weeks, and 16 weeks. At 16 weeks, tissues were harvested, weighed, and analyzed by histology, immunofluorescence, real-time quantitative polymerase chain reaction, and enzyme-linked immunosorbent assays. We found that female R848-treated mice had increased serum anti-Smith and immunoglobulin G complex deposition in the kidney, heart, and brain consistent with SLE-like etiology. Tissue analysis revealed significant enlargement of the spleen in both female and male R848-treated mice, with only cardiac and renal enlargement in females compared to their respective controls. Echocardiographic imaging revealed left ventricular wall thickening by 4 weeks that was followed by a progressive increase in left ventricular internal diameters and subsequent decrease in ejection fraction over the 16-week time course in female mice. We found that circulating levels of soluble vascular adhesion molecule-1 and soluble intracellular adhesion molecule-1 were increased in both female and male R848-treated mice, whereas cardiac and renal fibrosis were significantly increased in only female R848-treated mice. Our data demonstrate that R848 treatment of SLE-prone B6.Nba2 mice is a novel preclinical model to study the sex-dependent pathophysiologic mechanisms of SLE-like CVD.

Early elevations in arterial pressure: a contributor to rapid depressive symptom emergence in female Zucker rats with metabolic disease?

One of the growing challenges to public health and clinical outcomes is the emergence of cognitive impairments, particularly depressive symptom severity, because of chronic elevations in metabolic disease and cerebrovascular disease risk. To more clearly delineate these relationships and to assess the potential for sexual dimorphism, we used lean (LZR) and obese Zucker rats (OZR) of increasing age to determine relationships between internal carotid artery (ICA) hemodynamics, cerebral vasculopathies, and the emergence of depressive symptoms. Male OZR exhibited progressive elevations in perfusion pressure within the ICA, which were paralleled by endothelial dysfunction, increased cerebral arterial myogenic activation, and reduced cerebral cortex microvessel density. In contrast, female OZR exhibited a greater degree of ICA hypertension than male OZR but maintained normal endothelial function, myogenic activation, and microvessel density to an older age range than did males. Although both male and female OZR exhibited significant and progressive elevations in depressive symptom severity, these were significantly worse in females. Finally, plasma cortisol concentration was elevated higher and at a younger age in female OZR as compared with males, and this difference was maintained to final animal usage at ∼17 wk of age. These results suggest that an increased severity of blood pressure waves may penetrate the cerebral circulation more deeply in female OZR than in males, which may predispose the females to a more severe emergence of depressive symptoms with chronic metabolic disease, whereas males may be more predisposed to more direct cerebral vasculopathies (e.g., stroke, transient ischemic attack).NEW & NOTEWORTHY We provide novel insight that the superior maintenance of cerebrovascular endothelial function in female versus male rats with chronic metabolic disease buffers myogenic activation of cerebral resistance arteries/arterioles despite worsening hypertension. As hypertension development is earlier and more severe in females, potentially due to an elevated stress response, the blunted myogenic activation allows greater arterial pressure wave penetrance into the cerebral microcirculation and is associated with accelerated emergence/severity of depressive symptoms in obese female rats.

The Role of Cerebral Activation in the Sleep–Waking Cycle

The Role of Cerebral Activation in the Sleep–Waking Cycle

Functional connectivity and cerebral cortex activation during the resting state and verbal fluency tasks for patients with mild cognitive impairment, Lewy body dementia, and Alzheimer's disease: A multi-channel fNIRS study

ObjectiveTo explore changes in cerebral cortex activation and functional connectivity during resting-state and verbal fluency tasks in patients with different types of dementia. MethodsWe recorded oxygenated hemoglobin concentration (HbO) signals detected by functional near-infrared spectroscopy (fNIRS) from the prefrontal cortex, partial parietal cortex, and cortex of the temporal lobe in four groups of participants: mild cognitive impairment (MCI), Lewy body dementia (LBD), Alzheimer's disease (AD), and cognitively normal (CN). ResultsThe study recruited 120 older adults with MCI (n = 30), LBD (n = 28), AD (n = 30), or CN (n = 32). The mean functional connectivity of the frontal and temporal lobe in resting state was significantly less in the AD (0.19 ± 0.11) group than in the MCI (0.23 ± 0.11), LBD (0.29 ± 0.12), and CN (0.40 ± 0.11) groups (p < 0.001). Further, the mean HbO concentrations in the brain regions and channels were significantly lower in the AD group than in the LBD and MCI groups (p < 0.001). Cognitive levels correlated significantly with the mean HbO concentrations in the resting state and verbal fluency task conditions. ConclusionThe fNIRS HbO signals significantly differed in the cerebral cortex regions in participants with different types of dementia. These findings suggest that fNIRS can effectively enhance the differential diagnosis and assessment of dementia.

Glyoxalase 1 overexpression improves neurovascular coupling and limits development of mild cognitive impairment in a mouse model of type 1 diabetes.

Diabetes is associated with cognitive impairment, but the underlying mechanism remains unclear. Methylglyoxal (MGO), a precursor to advanced glycation endproducts (AGEs), is elevated in diabetes and linked to microvascular dysfunction. In this study, overexpression of the MGO-detoxifying enzyme glyoxalase 1 (Glo1) was used in a mouse model of diabetes to explore whether MGO accumulation in diabetes causes cognitive impairment. Diabetes was induced with streptozotocin. Fasting blood glucose, cognitive function, cerebral blood flow, neurovascular coupling (NVC), Glo1 activity, MGO and AGEs were assessed. In diabetes, MGO-derived hydroimidazolone-1 increased in the cortex, and was decreased in Glo1-overexpressing mice compared to controls. Visuospatial memory was decreased in diabetes, but not in Glo1/diabetes. NVC response time was slightly increased in diabetes, and normalised in the Glo1-overexpressing group. No impact of diabetes or Glo1 overexpression on blood-brain barrier integrity or vascular density was observed. Diabetes induced a mild visuospatial memory impairment and slightly reduced NVC response speed and these effects were mitigated by Glo1. This study shows a link between MGO-related AGE accumulation and cerebrovascular/cognitive functions in diabetes. Modulation of the MGO-Glo1 pathway may be a novel intervention strategy in patients with diabetes who have cerebrovascular complications. KEY POINTS: Diabetes is associated with an increased risk of stroke, cognitive decline, depression and Alzheimer's disease, but the underlying mechanism remains unclear. Methylglyoxal (MGO), a highly reactive by-product of glycolysis, plays an important role in the development of diabetes-associated microvascular dysfunction in the periphery and is detoxified by the enzyme glyoxalase 1. Diabetes reduced visuospatial memory in mice and slowed the neurovascular coupling response speed, which was improved by overexpression of glyoxalase 1. MGO formation and MGO-derived advanced glycation endproduct (AGE) accumulation in the brain of diabetic mice are associated with a slight reduction in neurovascular coupling and mild cognitive impairment. The endogenous formation of MGO, and the accumulation of MGO-derived AGEs, might be a potential target in reducing the risk of vascular cognitive impairment in people with diabetes.

Brain activation in older adults with hypertension and normotension during standing balance task: an fNIRS study.

Hypertension (HT) is a common chronic disease in older adults. It not only leads to dizziness and other symptoms affecting balance in older adults with HT but also affects the hemodynamics of the cerebral cortex. At present, potential neural mechanisms of balance control in older adults with HT are still unclear. Therefore, this study aimed to explore the differences in the center of pressure (COP) and cerebral cortex activation between older adults with HT and normotension (NT) during standing balance tasks. This study May provide guidance for the early detection of the risk of falls among older adults with HT and the development of clinical rehabilitation strategies. In this cross-sectional study, 30 older adults with NT (NT group) and 27 older adults with HT (HT group) were subjected to three conditions: task 1, standing with eyes open on a stable surface; task 2, standing with eyes closed on a stable surface; and task 3, standing with eyes open on the surface of the foam pad. Cortical hemodynamic reactions were measured using functional near-infrared spectroscopy, and COP parameters were measured using a force plate. The mean velocity of the COP in the medial-lateral direction in the NT group was significantly higher than that in the HT group (F = 5.955, p = 0.018) during task 3. When proprioception was disturbed, the activation of the left premotor cortex and supplementary motor cortex in the HT group was significantly lower than that in the NT group (F = 14.381, p < 0.001). The standing balance function of older adults with HT does not appear to be worse based on COP parameters than those of older adults with NT. This study revealed that the changes in the central cortex related to standing balance appear to be more indicative of balance control deficits in older adults with HT than changes in peripheral COP parameters, suggesting the importance of the early evaluation of cortical activation in older adults with HT at risk of falls.

Abnormal brain regional activity in acute thyrotoxic myopathy assessed by resting-state functional MRI.

The neurophysiological mechanisms underlying manifestations of bulbar paralysis in acute thyrotoxic myopathy (ATM) and the afflicted brain areas are unclear. We used resting-state functional magnetic resonance imaging (rs-fMRI) to evaluate the regional brain activities in patients with ATM. In total, 16 patients with ATM, 16 patients with hyperthyroidism without ATM, and 16 healthy controls underwent functional MRI scans. By calculating the fractional amplitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo), and functional connectivity (FC), we assessed variations in resting-state cerebral activity. The correlation between the resting-state functional indexes and clinical assessments was also explored. Compared to the hyperthyroid patients, patients with ATM had stronger ReHo in the left precentral gyrus, reduced ReHo in the left orbitofrontal gyrus (OFG), and decreased FC in the left precentral gyri, left superior frontal gyrus (SFG), and left middle frontal gyrus (MFG). Patients with ATM showed reduced fALFF and ReHo in the right SFG and decreased ReHo in the bilateral supplementary motor area (SMA). A significantly decreased FC in the left SFG and left MFG, right precentral gyrus, and the orbital part of the right interior frontal gyrus was observed in patients with ATM compared to healthy controls. Additionally, fALFF and ReHo values were positively correlated with serum thyroid-related hormones and antibodies. The findings of rs-fMRI demonstrate that particular brain regions' functional activity was aberrant in individuals with ATM, especially in SFG area. This finding may help with better understanding of underlying pathophysiology of patients with ATM.

EEG-based epileptic seizure detection using deep learning techniques: A survey

Epilepsy is a complex neurological disorder marked by recurrent seizures, often stemming from abnormal discharge of the brain. Electroencephalogram (EEG) captures temporal and spatial shifts in cerebral electrical activity, holding pivotal diagnostic and therapeutic value for epilepsy. Deep learning techniques have made remarkable progress in EEG-based seizure detection over recent years. This review is dedicated to exploring seizure detection approaches based on deep learning, focusing on three distinct avenues. Primarily, we delve into the application of canonical deep learning methods in epilepsy detection. Subsequently, a more in-depth study was conducted on the hybrid models of deep learning. Next, the third is the integration of deep learning and traditional machine learning strategies. Finally, the challenges and future prospects related to this topic are put forward. The uniqueness of this review lies in its novel and comprehensive perspective on the latest research on deep learning-based epilepsy detection by systematically classifying methods, visualizing research progress, and addressing challenges and gaps in current research. It can provide valuable guidance for researchers who want to delve into the field of epileptic seizure detection based on EEG signals.

The gamma-band activity model of the near-death experience: a critique and a reinterpretation.

Near-death experience (NDE) is a transcendent mental event of uncertain etiology that arises on the cusp of biological death. Since the discovery of NDE in the mid-1970s, multiple neuroscientific theories have been developed in an attempt to account for it in strictly materialistic or reductionistic terms. Therefore, in this conception, NDE is at most an extraordinary hallucination without any otherworldly, spiritual, or supernatural denotations. During the last decade or so, a number of animal and clinical studies have emerged which reported that about the time of death, there may be a surge of high frequency electroencephalogram (EEG) at a time when cortical electrical activity is otherwise at a very low ebb. This oscillatory rhythm falls within the range of the enigmatic brain wave-labelled gamma-band activity (GBA). Therefore, it has been proposed that this brief, paradoxical, and perimortem burst of the GBA may represent the neural foundation of the NDE. This study examines three separate but related questions concerning this phenomenon. The first problem pertains to the electrogenesis of standard GBA and the extent to which authentic cerebral activity has been contaminated by myogenic artifacts. The second problem involves the question of whether agents that can mimic NDE are also underlain by GBA. The third question concerns the electrogenesis of the surge in GBA itself. It has been contended that this is neither cortical nor myogenic in origin. Rather, it arises in a subcortical (amygdaloid) location but is recorded at the cortex via volume conduction, thereby mimicking standard GBA. Although this surge of GBA contains genuine electrophysiological activity and is an intriguing and provocative finding, there is little evidence to suggest that it could act as a kind of neurobiological skeleton for a phenomenon such as NDE.

Effects of repeated cryostimulation exposures on sleep and wellness in healthy young adults

The aim of this study was to evaluate the effects of daily whole-body cryostimulation (WBC) sessions during 5 consecutive days on wellness and sleep parameters in healthy young men and women. Twenty healthy subjects (9 women; 11 men) aged 23.1 ± 2.6 years old participated in this randomized protocol, with 5 consecutive days with (CRYO) or without WBC (CONT) exposure. Sleep was analyzed over the 5 nights in each condition. Sleep quality and quantity were assessed via actimetry, cerebral activity and questionnaires. Nocturnal heart rate variability (HRV) was also recorded and questionnaires were given to assess wellness and mood. Repeated WBC exposures had a beneficial impact on mood and anxiety. It also improved subjective sleep quality (scored from 3.6 ± 0.5 pre to 3.9 ± 0.3), especially in women. Also, repeated WBC sessions modulated sleep architecture by increasing slow wave sleep duration (+7.3 ± 16.8 min) during the nights without impacting other sleep parameters, nor nocturnal HRV. In conclusion, repeated WBC seems to be an effective strategy to improve slow wave sleep duration in healthy young subjects. The reported psychological improvements may better benefit women than men.

Focused magnetic stimulation for motor recovery after stroke

Background and objectivesThe effects of noninvasive focused magnetothermal brain stimulation using magnetic nanoparticles (MNPs) on post-stroke motor deficits and metabolic dormancy in subacute ischemic injury are not well-established. This study examined if magnetothermal brain stimulation using magnetic nanoparticles (Nano-MS) enhances motor recovery after stroke. MethodsWe randomly distributed rats into Sham, Control, MNP injection only, and Nano-MS groups. We administered focused magnetic stimulation for 30 min daily following an MNP injection (15 mg/mL) into the targeted motor cortex via the carotid artery three weeks after the transient (90 min) middle cerebral artery occlusion. We assessed motor functionality via behavioral tests and conducted positron emission tomography (PET) imaging to verify cerebral metabolic activity. We assessed neuronal excitability, neuroinflammation, blood-brain barrier (BBB) integrity, and neurogenesis four weeks post-stroke. ResultsThe Nano-MS group exhibited significantly improved motor deficits and cerebral metabolic activity compared to the Control and MNP groups (p < 0.05). Focused Nano-MS modulated neuronal excitability, evident by a depolarized action potential threshold for spike initiation and reduced firing frequency post-stroke. The Nano-MS group demonstrated markedly decreased inflammatory markers, such as IL-1β, IL-6, TNF-α, MCP-1, and ICAM-1, compared to the Control and MNP groups. BBB integrity and immunofluorescence for neurogenesis markers were substantially improved in the Nano-MS group. ConclusionsFocused Nano-MS facilitates the recovery of motor deficits and metabolic inactivity in the brain by effectively modulating excitability, reducing neuroinflammation, enhancing BBB stability, and promoting neurogenesis. Nano-MS is a potential novel, noninvasive therapy for stroke rehabilitation. Further investigation is warranted.

Ocular dominance and its association with retinal thickness profile - A cross-sectional study.

The retinal thickness profile is essential for detecting ocular diseases like glaucoma and other optic neuropathies. The retinal nerve fiber layer (RNFL) thickness is affected by age, ethnicity, axial length, optic disc area, and inter-eye differences. Ocular dominance has a strong functional correlation with cerebral cortical activity. However, its relationship with RNFL thickness profile is yet to be fully established. A cross-sectional study was conducted in 136 healthy adults to study the association between ocular dominance and RNFL parameters measured by Spectral domain optical coherence tomography (SD-OCT) and to study the association of ocular dominance with other parameters such as handedness, intraocular pressure, average axial length, average keratometry, and refractive error. Sighting ocular dominance was detected using the Miles test, and sensory ocular dominance was detected using the fogging test. Visual acuity and refraction assessment were done, and the patients underwent ocular biometry using the Lenstar 900 machine to measure the axial length and keratometry. The RNFL thickness was measured using the Cirrus HD optical coherence tomographer. One hundred and thirty-two (97.06%) individuals were right-handed, four (2.94%) were left-handed, 108 (79.41%) participants were right eye dominant, and 28 (20.59%) were left eye dominant. There was 100% agreement between sighting and sensory ocular dominance. The average RNFL thickness and other measured ocular parameters were comparable in the dominant and nondominant eyes. Regardless of dominance, the left eyes in the study cohort had a greater statistically significant difference in superior RNFL thickness (P < 0.05), which correlated with increased central macular thickness. Ocular dominance occurred mostly in the right eye. The RNFL thickness profile is not associated with ocular dominance in emmetropic and mild myopic individuals with normal best corrected visual acuity.

Employing Siamese Networks as Quantitative Biomarker for Assessing the Effect of Dolphin-Assisted Therapy on Pediatric Cerebral Palsy.

This study explores the potential of using a Siamese Network as a biomarker for assessing the effectiveness of Dolphin-Assisted Therapy (DAT) in children with Spastic Cerebral Palsy (SCP). The problem statement revolves around the need for objective measures to evaluate the impact of DAT on patients with SCP, considering the subjective nature of traditional assessment methods. The methodology involves training a Siamese network, a type of neural network designed to compare similarities between inputs, using data collected from SCP patients undergoing DAT sessions. The study employed Event-Related Potential (ERP) and Fast Fourier Transform (FFT) analyses to examine cerebral activity and brain rhythms, proposing the use of SNN to compare electroencephalographic (EEG) signals of children with cerebral palsy before and after Dolphin-Assisted Therapy. Testing on samples from four children yielded a high average similarity index of 0.9150, indicating consistent similarity metrics before and after therapy. The network is trained to learn patterns and similarities between pre- and post-therapy evaluations, in order to identify biomarkers indicative of therapy effectiveness. Notably, the Siamese Network's architecture ensures that comparisons are made within the same feature space, allowing for more accurate assessments. The results of the study demonstrate promising findings, indicating different patterns in the output of the Siamese Network that correlate with improvements in symptoms of SCP post-DAT. Confirming these observations will require large, longitudinal studies but such findings would suggest that the Siamese Network could have utility as a biomarker in monitoring treatment responses for children with SCP who undergo DAT and offer them more objective as well as quantifiable manners of assessing therapeutic interventions. Great discrepancies in neuronal voltage perturbations, 7.9825 dB on average at the specific samples compared to the whole dataset (6.2838 dB), imply a noted deviation from resting activity. These findings indicate that Dolphin-Assisted Therapy activates particular brain regions specifically during the intervention.

Imaging the cerebral vasculature at different scales: translational tools to investigate the neurovascular interfaces.

The improvements in imaging technology opened up the possibility to investigate the structure and function of cerebral vasculature and the neurovascular unit with unprecedented precision and gaining deep insights not only on the morphology of the vessels, but also regarding their function and regulation related to the cerebral activity. In this review we will dissect the different imaging capabilities regarding the cerebrovascular tree, the neurovascular unit and the hemodynamic response function and thus the vascular-neuronal coupling. We will discuss both clinical and preclinical setting, with a final discussion on the current scenery in cerebrovascular imaging where Magnetic Resonance Imaging and multimodal Microscopy emerge as the most potent and versatile tools respectively in the clinical and preclinical context.

Avalanche burial pathophysiology - a unique combination of hypoxia, hypercapnia and hypothermia.

For often unclear reasons, the survival times of critically buried avalanche victims vary widely from minutes to hours. Individuals can survive and sustain organ function if they can breathe under the snow and maintain sufficient delivery of oxygen and efflux of carbon dioxide. We review the physiological responses of humans to critical avalanche burial, a model which shares similarities and differences with apnoea and accidental hypothermia. Within a few minutes of burial, an avalanche victim is exposed to hypoxaemia and hypercapnia, which have important effects on the respiratory and cardiovascular systems and pose a major threat to the central nervous system. As burial time increases, an avalanche victim also develops hypothermia. Despite progressively reduced metabolism, reduced oxygen and increased carbon dioxide tensions may exacerbate the pathophysiological consequences of hypothermia. Hypercapnia seems to be the main cause of cardiovascular instability, which, in turn, is the major reason for reduced cerebral oxygenation despite reductions in cerebral metabolic activity caused by hypothermia. 'Triple H syndrome' refers to the interaction of hypoxia, hypercapnia and hypothermia in a buried avalanche victim. Future studies should investigate how the respiratory gases entrapped in the porous snow structure influence the physiological responses of buried individuals and how haemoconcentration, blood viscosity and cell deformability affect blood flow and oxygen delivery. Attention should also be devoted to identifying strategies to prolong avalanche survival by either mitigating hypoxia and hypercapnia or reducing core temperature so that neuroprotection occurs before the onset of cerebral hypoxia.