The Experts below are selected from a list of 143928 Experts worldwide ranked by ideXlab platform
Yury Koush - One of the best experts on this subject based on the ideXlab platform.
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can we predict real time fmri neurofeedback learning success from pre training Brain activity
bioRxiv, 2020Co-Authors: Stavros Skouras, Ronald Sladky, Amelie Haugg, Amalia Mcdonald, Camero R Craddock, Matthias Kirschne, Marcus Herdene, Yury KoushAbstract:Abstract Neurofeedback training has been shown to influence behavior in healthy participants as well as to alleviate clinical symptoms in neurological, psychosomatic, and psychiatric patient populations. However, many real-time fMRI neurofeedback studies report large interindividual differences in learning success. The factors that cause this vast variability between participants remain unknown and their identification could enhance treatment success. Thus, here we employed a meta-analytic approach including data from 24 different neurofeedback studies with a total of 401 participants, including 140 patients, to determine whether levels of activity in Target Brain regions during pre-training functional localizer or no-feedback runs (i.e., self-regulation in the absence of neurofeedback) could predict neurofeedback learning success. We observed a slightly positive correlation between pre-training activity levels during a functional localizer run and neurofeedback learning success, but we were not able to identify common Brain-based success predictors across our diverse cohort of studies. Therefore, advances need to be made in finding robust models and measures of general neurofeedback learning, and in increasing the current study database to allow for investigating further factors that might influence neurofeedback learning.
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data driven tensor independent component analysis for model based connectivity neurofeedback
NeuroImage, 2019Co-Authors: Yury Koush, Nemanja Masala, Frank Scharnowski, Dimitri Van De VilleAbstract:Neurofeedback based on real-time functional MRI is an emerging technique to train voluntary control over Brain activity in healthy and disease states. Recent developments even allow for training of Brain networks using connectivity feedback based on dynamic causal modeling (DCM). DCM is an influential hypothesis-driven approach that requires prior knowledge about the Target Brain network dynamics and the modulatory influences. Data-driven approaches, such as tensor independent component analysis (ICA), can reveal spatiotemporal patterns of Brain activity without prior assumptions. Tensor ICA allows flexible data decomposition and extraction of components consisting of spatial maps, time-series, and session/subject-specific weights, which can be used to characterize individual neurofeedback regulation per regulation trial, run, or session. In this study, we aimed to better understand the spatiotemporal Brain patterns involved and affected by model-based feedback regulation using data-driven tensor ICA. We found that task-specific spatiotemporal Brain patterns obtained using tensor ICA were highly consistent with model-based feedback estimates. However, we found that the DCM approach captured specific network interdependencies that went beyond what could be detected with either general linear model (GLM) or ICA approaches. We also found that neurofeedback-guided regulation resulted in activity changes that were characteristic of the mental strategies used to control the feedback signal, and that these activity changes were not limited to periods of active self-regulation, but were also evident in distinct gradual recovery processes during subsequent rest periods. Complementary data-driven and model-based approaches could aid in interpretation of the neurofeedback data when applied post-hoc, and in the definition of the Target Brain area/pattern/network/model prior to the neurofeedback training study when applied to the pilot data. Systematically investigating the triad of mental effort, spatiotemporal Brain network changes, and activity and recovery processes might lead to a better understanding of how learning with neurofeedback is accomplished, and how such learning can cause plastic Brain changes along with specific behavioral effects.
Richard G Ellenbogen - One of the best experts on this subject based on the ideXlab platform.
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specific Targeting of Brain tumors with an optical magnetic resonance imaging nanoprobe across the blood Brain barrier
Cancer Research, 2009Co-Authors: Omid Veiseh, Conroy Sun, Chen Fang, Narayan Bhattarai, Jonathan Gunn, Forrest M Kievit, Barbara Pullar, Donghoon Lee, Richard G EllenbogenAbstract:Nanoparticle-based platforms have drawn considerable attention for their potential effect on oncology and other biomedical fields. However, their in vivo application is challenged by insufficient accumulation and retention within tumors due to limited specificity to the Target, and an inability to traverse biological barriers. Here, we present a nanoprobe that shows an ability to cross the blood-Brain barrier and specifically Target Brain tumors in a genetically engineered mouse model, as established through in vivo magnetic resonance and biophotonic imaging, and histologic and biodistribution analyses. The nanoprobe is comprised of an iron oxide nanoparticle coated with biocompatible polyethylene glycol–grafted chitosan copolymer, to which a tumor-Targeting agent, chlorotoxin, and a near-IR fluorophore are conjugated. The nanoprobe shows an innocuous toxicity profile and sustained retention in tumors. With the versatile affinity of the Targeting ligand and the flexible conjugation chemistry for alternative diagnostic and therapeutic agents, this nanoparticle platform can be potentially used for the diagnosis and treatment of a variety of tumor types. [Cancer Res 2009;69(15):6200–7]
Sung Ho Jang - One of the best experts on this subject based on the ideXlab platform.
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the direct pathway from the Brainstem reticular formation to the cerebral cortex in the ascending reticular activating system a diffusion tensor imaging study
Neuroscience Letters, 2015Co-Authors: Sung Ho Jang, Hyeok Gyu KwonAbstract:Precise evaluation of the ascending reticular activating system (ARAS) is important for diagnosis, prediction of prognosis, and management of patients with disorders of impaired consciousness. In the current study, we attempted to reconstruct the direct neural pathway between the Brainstem reticular formation (RF) and the cerebral cortex in normal subjects, using diffusion tensor imaging (DTI). Forty-one healthy subjects were recruited for this study. DTIs were performed using a sensitivity-encoding head coil at 1.5Tesla with FMRIB Software Library. For connectivity of the Brainstem RF, we used two regions of interest (ROIs) for the Brainstem RF (seed ROI) and the thalamus and hypothalamus (exclusion ROI). Connectivity was defined as the incidence of connection between the Brainstem RF and Target Brain regions at the threshold of 5 and 50 streamlines. Regarding the thresholds of 5 and 50, the Brainstem RF showed high connectivity to the lateral prefrontal cortex (lPFC, 67.1% and 20.7%) and ventromedial prefrontal cortex (vmPFC, 50.0% and 18.3%), respectively. In contrast, the Brainstem RF showed low connectivity to the primary motor cortex (31.7% and 3.7%), premotor cortex (24.4% and 3.7%), primary somatosensory cortex (23.2% and 2.4%), orbitofrontal cortex (17.1% and 7.3%), and posterior parietal cortex (12.2% and 0%), respectively. The Brainstem RF was mainly connected to the prefrontal cortex, particularly lPFC and vmPFC. We believe that the methodology and results of this study would be useful to clinicians involved in the care of patients with impaired consciousness and researchers in studies of the ARAS.
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the neural connectivity of the intralaminar thalamic nuclei in the human Brain a diffusion tensor tractography study
Neuroscience Letters, 2014Co-Authors: Sung Ho Jang, Hyoung Won Lim, Sang Seok YeoAbstract:Research on the neural connectivity of the intralaminar thalamic nuclei (ILN) has been limited. Since the introduction of diffusion tensor imaging (DTI), many probabilistic DTI studies have reported on neural connectivity of neural structures in normal subjects. However, no study on the neural connectivity of the ILN has been reported so far. In this study, using probabilistic DTI, we investigated the neural connectivity of the ILN in normal subjects. A total of 40 healthy subjects were recruited for this study. A seed region of interest was placed on the ILN of the thalamus using the FMRIB Software Library. Connectivity was defined as the incidence of connection between the ILN and Target Brain areas. We found high connectivity between the ILN and arousal-related areas (prefrontal cortex 100%, reticular formation 100%, pedunculopontine nucleus 97.5%, basal foreBrain 95%, and hypothalamus 92.5% at threshold 5), attention related area (prefrontal cortex 100% at threshold 5), and sensori-motor function related areas (primary motor cortex 100%, globus pallidus 100%, putamen 98.8%, premotor cortex 96.3%, primary somatosensory cortex 95.0%, caudate nucleus 92.5%, and posterior parietal cortex 90.0% at threshold 5). Findings of this study showed that ILN has high connectivity with Brain areas related to arousal, attention, and sensorimotor function. This result indicates a close association of ILN with these functions in the human Brain.
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neural connectivity of the lateral geniculate body in the human Brain diffusion tensor imaging study
Neuroscience Letters, 2014Co-Authors: Hyeok Gyu Kwon, Sung Ho JangAbstract:A few studies have reported on the neural connectivity of some neural structures of the visual system in the human Brain. However, little is known about the neural connectivity of the lateral geniculate body (LGB). In the current study, using diffusion tensor tractography (DTT), we attempted to investigate the neural connectivity of the LGB in normal subjects. A total of 52 healthy subjects were recruited for this study. A seed region of interest was placed on the LGB using the FMRIB Software Library which is a probabilistic tractography method based on a multi-fiber model. Connectivity was defined as the incidence of connection between the LGB and Target Brain areas at the threshold of 5, 25, and 50 streamlines. In addition, connectivity represented the percentage of connection in all hemispheres of 52 subjects. We found the following characteristics of connectivity of the LGB at the threshold of 5 streamline: (1) high connectivity to the corpus callosum (91.3%) and the contralateral temporal cortex (56.7%) via the corpus callosum, (2) high connectivity to the ipsilateral cerebral cortex: the temporal lobe (100%), primary visual cortex (95.2%), and visual association cortex (77.9%). The LGB appeared to have high connectivity to the corpus callosum and both temporal cortexes as well as the ipsilateral occipital cortex. We believe that the results of this study would be helpful in investigation of the neural network associated with the visual system and Brain plasticity of the visual system after Brain injury.
Thomas E Schlaepfer - One of the best experts on this subject based on the ideXlab platform.
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mood improvement after deep Brain stimulation of the internal globus pallidus for tardive dyskinesia in a patient suffering from major depression
Journal of Psychiatric Research, 2007Co-Authors: Markus Kosel, Volker Sturm, C Frick, Doris Lenartz, Gabriele Zeidler, Daniela Brodesser, Thomas E SchlaepferAbstract:Deep Brain stimulation (DBS) has the unique characteristic to very precisely Target Brain structures being part of functional Brain circuits in order to reversibly modulate their function. It is an established adjunctive treatment of advanced Parkinson's disease and has virtually replaced ablative techniques in this indication. Several cases have been published relating effectiveness in neuroleptics-induced tardive dyskinesia. It is also investigated as a potential treatment of mood disorders. We report on the case of a 62 years old female suffering from a treatment refractory major depressive episode with comorbid neuroleptic-induced tardive dyskinesia. She was implanted a deep Brain stimulation treatment system bilaterally in the globus pallidus internus and stimulated for 18 months. As well the dyskinesia as also the symptoms of depression improved substantially as measured by the Hamilton Rating Scale of Depression (HRSD) score and the Burke-Fahn-Marsden-Dystonia-Rating-Scale (BFMDRS) score. Scores dropped for HRSD from 26 at baseline preoperatively to 13 after 18 months; and for BFMDRS from 27 to 17.5. This case illustrates the potential of deep Brain stimulation as a technique to be investigated in the treatment of severe and disabling psychiatric and movement disorders. DBS at different intracerebral Targets being actually investigated for major depression might have similar antidepressant properties because they interact with the same cortico-basal ganglia-thalamocortical network found to be dysfunctional in major depression.
Frazao Renata - One of the best experts on this subject based on the ideXlab platform.
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Alzheimer-associated a Beta oligomers impact the central nervous system to induce peripheral metabolic deregulation
'EMBO', 2021Co-Authors: Clarke, Julia R., Lyra Silva, Natalia E M., Figueiredo, Claudia P., Frozza, Rudimar L., Ledo, Jose H., Beckman Danielle, Katashima, Carlos K., Razolli Daniela, Carvalho, Bruno M., Frazao RenataAbstract:Alzheimer's disease (AD) is associated with peripheral metabolic disorders. Clinical/epidemiological data indicate increased risk of diabetes in AD patients. Here, we show that intracerebroventricular infusion of AD-associated A beta oligomers (A beta Os) in mice triggered peripheral glucose intolerance, a phenomenon further verified in two transgenic mouse models of AD. Systemically injected A beta Os failed to induce glucose intolerance, suggesting A beta Os Target Brain regions involved in peripheral metabolic control. Accordingly, we show that A beta Os affected hypothalamic neurons in culture, inducing eukaryotic translation initiation factor 2 alpha phosphorylation (eIF2 alpha-P). A beta Os further induced eIF2 alpha-P and activated proinflammatory IKK beta/NF-kappa B signaling in the hypothalamus of mice and macaques. A beta Os failed to trigger peripheral glucose intolerance in tumor necrosis factor-alpha (TNF-alpha) receptor 1 knockout mice. Pharmacological inhibition of Brain inflammation and endoplasmic reticulum stress prevented glucose intolerance in mice, indicating that A beta Os act via a central route to affect peripheral glucose homeostasis. While the hypothalamus has been largely ignored in the AD field, our findings indicate that A beta Os affect this Brain region and reveal novel shared molecular mechanisms between hypothalamic dysfunction in metabolic disorders and AD72190210CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIRO - FAPERJFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informaçãosem informaçãosem informação2012/12202-4Human Frontier Science Program; National Institute for Translational Neuroscience (INNT/Brazil); Canadian Institutes of Health Research (CIHR); Canada Research Chair
