Abstract 2713: Functional Recovery Associated with Connectivity Changes in Contralesional Hemisphere after Severe Transient Stroke.

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
WOO HYUN SHIM ◽  
Bruce Rosen ◽  
Jaeseung Jeong ◽  
Young Kim
Keyword(s):  
Functional Connectivity ◽  
Functional Recovery ◽  
Brain Connectivity ◽  
Control Group ◽  
Sprague Dawley ◽  
Sensorimotor Deficit ◽  
Stroke Models ◽  
Time Courses ◽  
The Right ◽  
The Brain

Stroke impairs connections in the brain system, commonly resulting in significant sensorimotor deficits. Some degree of functional recovery typically occurs even after a severe stroke, yet changes in the brain connectivity that underlie such recovery are poorly understood. In this study, using rat stroke models, we monitored functional connectivity when the sensorimotor deficit recovered after a severe ischemic stroke (defined DWI by more than 15% of the entire brain volume). We used seven Sprague-Dawley rats (∼350g), which showed nearly full recovery of both motor and sensory functions approximately 180 days after 90 min occlusion of the right middle cerebral artery. Six healthy age controlled rats were used for the control group. BOLD MRI time courses during rest (10min, TR=1s, 9 slices) were collected. Both the seed-voxel analysis and the ROI-based analysis were performed, in which seed voxels were selected in the left S1FL, and multiple ROIs were placed over the somatosensory regions. Stroke rats showed the markedly decreased functional connectivity in the ipsilesional side (right) for both voxelwise and ROI-based methods. Interestingly, in contralesional (non-stroke) side (left), the voxelwise connectivity spatially expanded into the entire cortical area. The cross-correlation coefficient values between ROI’s slightly increased in the contralesional hemisphere compared to the control rats. In conclusion, we demonstrated that the restoration of sensorimotor function is associated more with the increase and spatial expansion of functional connectivity within the contralesional than the ipsilesional hemisphere.

scholarly journals Multi-Hops Functional Connectivity Improves Individual Prediction of Fusiform Face Activation via a Graph Neural Network

2021 ◽  
Vol 14 ◽  
Author(s):  
Dongya Wu ◽  
Xin Li ◽  
Jun Feng
Keyword(s):  
Neural Network ◽  
Functional Connectivity ◽  
Brain Connectivity ◽  
Face Area ◽  
The Face ◽  
The Individual ◽  
The Right ◽  
And Function ◽  
The Relationship ◽  
The Brain

Brain connectivity plays an important role in determining the brain region’s function. Previous researchers proposed that the brain region’s function is characterized by that region’s input and output connectivity profiles. Following this proposal, numerous studies have investigated the relationship between connectivity and function. However, this proposal only utilizes direct connectivity profiles and thus is deficient in explaining individual differences in the brain region’s function. To overcome this problem, we proposed that a brain region’s function is characterized by that region’s multi-hops connectivity profile. To test this proposal, we used multi-hops functional connectivity to predict the individual face activation of the right fusiform face area (rFFA) via a multi-layer graph neural network and showed that the prediction performance is essentially improved. Results also indicated that the two-layer graph neural network is the best in characterizing rFFA’s face activation and revealed a hierarchical network for the face processing of rFFA.

scholarly journals Multi-hops functional connectivity improves individual prediction of fusiform face activation via a graph neural network

2020 ◽  
Author(s):  
Dongya Wu ◽  
Xin Li ◽  
Jun Feng
Keyword(s):  
Neural Network ◽  
Functional Connectivity ◽  
Brain Connectivity ◽  
Face Area ◽  
The Face ◽  
The Individual ◽  
The Right ◽  
And Function ◽  
The Relationship ◽  
The Brain

AbstractBrain connectivity plays an important role in determining the brain region’s function. Previous researchers proposed that the brain region’s function is characterized by that region’s input and output connectivity profiles. Following this proposal, numerous studies have investigated the relationship between connectivity and function. However, based on a preliminary analysis, this proposal is deficient in explaining individual differences in the brain region’s function. To overcome this problem, we proposed that a brain region’s function is characterized by that region’s multi-hops connectivity profile. To test this proposal, we used multi-hops functional connectivity to predict the individual face response of the right fusiform face area (rFFA) via a multi-layers graph neural network and showed that the prediction performance is essentially improved. Results also indicated that the 2-layers graph neural network is the best in characterizing rFFA’s face response and revealed a hierarchical network for the face processing of rFFA.

scholarly journals Exercise Ameliorates Spinal Cord Injury by Changing DNA Methylation

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 143
Author(s):  
Ganchimeg Davaa ◽  
Jin Young Hong ◽  
Tae Uk Kim ◽  
Seong Jae Lee ◽  
Seo Young Kim ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Cortex ◽  
Functional Recovery ◽  
Treadmill Exercise ◽  
Exercise Group ◽  
Control Group ◽  
Epigenetic Changes ◽  
Cord Injury ◽  
The Brain

Exercise training is a traditional method to maximize remaining function in patients with spinal cord injury (SCI), but the exact mechanism by which exercise promotes recovery after SCI has not been identified; whether exercise truly has a beneficial effect on SCI also remains unclear. Previously, we showed that epigenetic changes in the brain motor cortex occur after SCI and that a treatment leading to epigenetic modulation effectively promotes functional recovery after SCI. We aimed to determine how exercise induces functional improvement in rats subjected to SCI and whether epigenetic changes are engaged in the effects of exercise. A spinal cord contusion model was established in rats, which were then subjected to treadmill exercise for 12 weeks. We found that the size of the lesion cavity and the number of macrophages were decreased more in the exercise group than in the control group after 12 weeks of injury. Immunofluorescence and DNA dot blot analysis revealed that levels of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) in the brain motor cortex were increased after exercise. Accordingly, the expression of ten-eleven translocation (Tet) family members (Tet1, Tet2, and Tet3) in the brain motor cortex also elevated. However, no macrophage polarization was induced by exercise. Locomotor function, including Basso, Beattie, and Bresnahan (BBB) and ladder scores, also improved in the exercise group compared to the control group. We concluded that treadmill exercise facilitates functional recovery in rats with SCI, and mechanistically epigenetic changes in the brain motor cortex may contribute to exercise-induced improvements.

scholarly journals Quantitative Analysis of Diffusion Tensor Imaging in Chronic Hepatitis in Rats

2020 ◽  
Author(s):  
Mengping Huang ◽  
Xin Lu ◽  
Xiaofeng Wang ◽  
Jian Shu
Keyword(s):  
Chronic Hepatitis ◽  
Diffusion Tensor Imaging ◽  
Liver Fibrosis ◽  
Diffusion Tensor ◽  
Control Group ◽  
Sprague Dawley ◽  
Subcutaneous Injections ◽  
Sprague Dawley Rats ◽  
Pathological Stages ◽  
The Brain

Abstract Background Diffusion tensor imaging (DTI) is mainly used for detecting white matter fiber in the brain. From this, DTI has been applied to assess fiber in liver disorders by prior studies. But non-sufficient data has been obtained if DTI could be used for exactly staging chronic hepatitis. This study is to assess the value of DTI for staging of liver fibrosis (F), necroinflammatory activity (A), and steatosis (S) of chronic hepatitis in rats. Methods Seventy male Sprague-Dawley rats were divided into control group(n = 10) and experimental group(n = 60). The rat models of chronic hepatitis were established by abdominal subcutaneous injections of 40% CCl4. All rats underwent 3.0T MRI. ROIs were placed on DTI to estimate MR parameters (rADC value and FA value). Histopathology was the reference standard. Multiple linear regression was used to analyze the association between MR parameters and pathology. The differences in rADC value and FA value among pathological stages were evaluated by MANOVA or ANOVA. LSD was used to test the differences between each two groups. ROC analysis was performed. Results The numbers of each pathology were as follows: F0(n = 15), F1(n = 11), F2(n = 6), F3(n = 9), F4(n = 6); A0(n = 8), A1(n = 16), A2(n = 16), A3(n = 7); S0(n = 10), S1(n = 7), S2(n = 3), S3(n = 11), S4(n = 16). The rADC value had a negative correlation with liver fibrosis (r=-0.392, P = 0.008) and inflammation (r=-0.359, P = 0.015). FA value had a positive correlation with fibrosis (r = 0.409, P = 0.005). Significant differences were found in FA value between F4 and F0 ~ F3 (P = 0.03), while no significant differences among F0 ~ F3 were found (P > 0.05). AUC of FA value in differentiating F4 from F0 ~ F3 was 0.909(p < 0.001) with 83.3% Sensitivity, 85.4% specificity when the FA value was at the cut-off of 588.089(× 10− 6mm2/s). Conclusion FA value for DTI can distinguish early cirrhosis from normal, mild and moderate liver fibrosis.

scholarly journals Hypoconnectivity networks in schizophrenia patients: a voxelwise meta-analysis of rs-fMRI

2021 ◽  
Author(s):  
Silvia Ruiz-Torras ◽  
Oscar Fernández-Vazquez ◽  
Cristina Cañete-Massé ◽  
Maribel Peró-Cebollero ◽  
Joan Guàrdia-Olmos
Keyword(s):  
Brain Connectivity ◽  
Meta Analysis ◽  
Superior Temporal Gyrus ◽  
Interesting Case ◽  
Control Group ◽  
Precentral Gyrus ◽  
Healthy Controls ◽  
Health States ◽  
The Right ◽  
Work Done

Abstract In the last few years, the field of brain connectivity has focused on identifying biomarkers to describe different health states and to discriminate between patients and healthy controls through the characterization of brain networks. A particularly interesting case, because of the symptoms' severity, is the work done with samples of patients diagnosed with schizophrenia. This meta-analysis aims to identify connectivity networks with different activation patterns between people diagnosed with schizophrenia and healthy controls. Therefore, we collected primary studies exploring whole brain connectivity by functional magnetic resonance imaging at rest in patients with schizophrenia compared to healthy people. Thus, we identified 25 high-quality studies that included a total of 1285 people with schizophrenia and 1279 healthy controls. The results indicate hypoactivation in the right precentral gyrus and in the left superior temporal gyrus of people with schizophrenia compared with the control group. These regions have been linked to deficits in gesticulation and the experience of auditory hallucinations in people with schizophrenia. A study of heterogeneity demonstrated that the effect size was influenced by the sample size and type of analysis. These results imply new contributions to the knowledge, diagnosis, and treatment of schizophrenia both clinically and in research.

An Exploratory Pilot Study of Brain Activation and Functional Connectivity Induced by the “Goldberg” Variations 276 years after their Commission

2019 ◽  
Vol 34 (4) ◽  
pp. 191-197
Author(s):  
Christof Karmonik ◽  
Makiko Hirata ◽  
Saba Elias ◽  
J Todd Frazier
Keyword(s):  
Pilot Study ◽  
Functional Connectivity ◽  
Brain Connectivity ◽  
Brain Activation ◽  
Johann Sebastian Bach ◽  
Technical Development ◽  
The Subject ◽  
Goldberg Variations ◽  
The Brain

Around 1741, composer Johann Sebastian Bach published a long and complicated keyboard piece, calling it Aria with diverse variations for a harpsichord with two manuals. It was the capstone of a publication project called German Clavier-Übung (Keyboard Practice) where Bach wanted to show what was possible at the keyboard in terms of technical development, virtuosic finesse and compositional sophistication. The music is meticulously patterned, beginning with a highly ornamented Aria, the bass line of which fuels the 30 variations that follow. The piece is clearly divided into two parts with the second half beginning with an overture with a fanfare opening, in variation 16. The piece ends as it begins, with the return of the Aria. Here, we present an investigation into activation and connectivity in the brain of a pianist, who listened to her own recording of the “Goldberg” variation while undergoing a fMRI examination. Similarity of brain connectivity is quantified and compared with the subjective scores provided by the subject.

Inter-Hemispherical Investigations on the Functional Connectivity in Controls and Autism Spectrum Using Resting State fMRI

2020 ◽  
pp. 169-186
Author(s):  
S. Vidhusha ◽  
A. Kavitha
Keyword(s):  
Functional Connectivity ◽  
Granger Causality ◽  
Resting State ◽  
Cognitive Task ◽  
Resting State Fmri ◽  
Autism Spectrum ◽  
Control Group ◽  
Neural Connectivity ◽  
Activation Patterns ◽  
The Brain

Autism spectrum disorders are connected with disturbances of neural connectivity. Functional connectivity is typically examined during a cognitive task, but also exists in the absence of a task. While a number of studies have performed functional connectivity analysis to differentiate controls and autism individuals, this work focuses on analyzing the brain activation patterns not only between controls and autistic subjects, but also analyses the brain behaviour present within autism spectrum. This can bring out more intuitive ways to understand that autism individuals differ individually. This has been performed between autism group relative to the control group using inter-hemispherical analysis. Indications of under connectivity were exhibited by the Granger Causality (GC) and Conditional Granger Causality (CGC) in autistic group. Results show that as connectivity decreases, the GC and CGC values also get decreased. Further, to demark the differences present within the spectrum of autistic individuals, GC and CGC values have been calculated.

scholarly journals Mindfulness Meditation Is Related to Long-Lasting Changes in Hippocampal Functional Topology during Resting State: A Magnetoencephalography Study

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Anna Lardone ◽  
Marianna Liparoti ◽  
Pierpaolo Sorrentino ◽  
Rosaria Rucco ◽  
Francesca Jacini ◽  
...  
Keyword(s):  
Resting State ◽  
Mindfulness Meditation ◽  
Brain Connectivity ◽  
Brain Networks ◽  
Brain Network ◽  
Long Term Effects ◽  
Age Related ◽  
Functional Topology ◽  
The Right ◽  
The Brain

It has been suggested that the practice of meditation is associated to neuroplasticity phenomena, reducing age-related brain degeneration and improving cognitive functions. Neuroimaging studies have shown that the brain connectivity changes in meditators. In the present work, we aim to describe the possible long-term effects of meditation on the brain networks. To this aim, we used magnetoencephalography to study functional resting-state brain networks in Vipassana meditators. We observed topological modifications in the brain network in meditators compared to controls. More specifically, in the theta band, the meditators showed statistically significant (p corrected = 0.009) higher degree (a centrality index that represents the number of connections incident upon a given node) in the right hippocampus as compared to controls. Taking into account the role of the hippocampus in memory processes, and in the pathophysiology of Alzheimer’s disease, meditation might have a potential role in a panel of preventive strategies.

scholarly journals Contralateral spreading of substances following intratympanic nanoparticle-conjugated gentamicin injection in a rat model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sang-Yeon Lee ◽  
Jeonghyo Kim ◽  
Sangjin Oh ◽  
Gaon Jung ◽  
Ki-Jae Jeong ◽  
...  
Keyword(s):  
Eustachian Tube ◽  
Rat Model ◽  
Control Group ◽  
Fluorescent Nanoparticles ◽  
Sprague Dawley ◽  
Surface Charges ◽  
Cochlear Hair Cells ◽  
Intratympanic Injection ◽  
Group 2 ◽  
The Right

Abstract This study was performed to investigate the Eustachian tube as a potential route for contralateral spreading following intratympanic nanoparticle (NP)-conjugated gentamicin injection in a rat model. Sprague–Dawley rats were divided into three groups and substances were injected in the right ear: group 1 (fluorescent magnetic nanoparticles [F-MNPs], n = 4), group 2 (F-MNP-conjugated gentamicin [F-MNP@GM], n = 2), and control group (no injections, n = 2). T2-weighted sequences corresponding to the regions of interest at 1, 2, and 3 h after intratympanic injection were evaluated, along with immunostaining fluorescence of both side cochlea. The heterogeneous signal intensity of F-MNPs and F-MNP@GM on T2-weighted images, observed in the ipsilateral tympanum, was also detected in the contralateral tympanum in 4 out of 6 rats, recapitulating fluorescent nanoparticles in the contralateral cochlear hair cells. Computational simulations demonstrate the contralateral spreading of particles by gravity force following intratympanic injection in a rat model. The diffusion rate of the contralateral spreading relies on the sizes and surface charges of particles. Collectively, the Eustachian tube could be a route for contralateral spreading following intratympanic injection. Caution should be taken when using the contralateral ear as a control study investigating inner-ear drug delivery through the transtympanic approach.

Dexmedetomidine elevates the lethal dose threshold of bupivacaine in rats: A dosing study

2019 ◽  
Vol 39 (3) ◽  
pp. 365-373
Author(s):  
L Pan ◽  
Y Zhang ◽  
Y He ◽  
Z Chen ◽  
S Wang ◽  
...  
Keyword(s):  
Femoral Vein ◽  
Lethal Dose ◽  
Control Group ◽  
Sprague Dawley ◽  
Dose Threshold ◽  
Sd Rats ◽  
Group 12 ◽  
Group 3 ◽  
The Right ◽  
Group 1

Dexmedetomidine (DMED), an alpha-2 adrenoreceptor agonist, has been widely used in regional anesthesia procedures. However, the effect of DMED on local anesthetic cardiotoxicity has not been well delineated. This study consisted of two experiments. In experiment A, 42 Sprague–Dawley (SD) rats were randomly divided into 6 groups ( n = 7), each group was pretreated with DMED 0 μg kg−1 (D0 group), 1 μg kg−1 (D1 group), 3 μg kg−1 (D3 group), 6 μg kg−1 (D6 group), 12 μg kg−1 (D12 group), and 24 μg kg−1 (D24 group), administered through the right femoral vein. In experiment B, 20 SD rats were randomly divided into 4 groups ( n = 5), such as control group, DMED group, yohimbine (YOH) group, and DMED + YOH group. Each subgroup in experiment B was also pretreated similarly as in experiment A. After pretreatment of rats as described above (in experiments A and B), bupivacaine 2.5 mg kg−1 min−1 was infused to induce cardiac arrest. In experiment A, the lethal dose threshold of bupivacaine and plasma bupivacaine concentration in D3 and D6 group were higher than the other groups. In experiment B, there was no interaction between DMED and YOH in lethal dose threshold, arrhythmia time, plasma concentration of bupivacaine, and myocardial content of bupivacaine. DMED doses of 3–6 μg kg−1 elevated the lethal dose threshold of bupivacaine without involvement of the alpha-2 adrenoceptors.

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