The Experts below are selected from a list of 6459 Experts worldwide ranked by ideXlab platform
M. S. Bruno - One of the best experts on this subject based on the ideXlab platform.
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gabaergic neurotransmission in the c57bl 10 sps sps mouse mutant a model of Absence Seizures
Experimental Neurology, 1991Co-Authors: J G Ortiz, Arnaldo E. Negrón, A.p. Thomas, H. Heimer, J. A. Moreira, Mayra L. Cordero, J. Aranda, M. S. BrunoAbstract:Abstract The C57BL 10 , sps sps mouse mutant displays generalized Absence Seizure-like behavior. In these mice, glutamic acid decarboxylase activity is reduced in the cortex and hippocampus. Tritiated flunitrazepam binding (3H-flu) is reduced in these areas, as well as in midbrain, cerebellum, and pons-medulla. Quantitative [3H]-flunitrazepam binding autoradiography confirms these observations. GABA uptake by synaptosomes from sps sps mice is also reduced in all the areas studied. Potassium-stimulated, Ca2+-dependent release of radioactivity from synaptosomes preloaded with [14C]-GABA is reduced in the hippocampus, increased in midbrain and pons-medulla, but remains unaltered in the cortex. These results suggest region-specific alterations in GABAergic neurotransmission that may be responsible for the Absence-like Seizures in C57BL 10 , sps sps mice.
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GABAergic neurotransmission in the C57BL/10 sps/sps mouse mutant: a model of Absence Seizures.
Experimental neurology, 1991Co-Authors: Arnaldo E. Negrón, A.p. Thomas, H. Heimer, J. A. Moreira, Mayra L. Cordero, J. Aranda, M. S. BrunoAbstract:Abstract The C57BL 10 , sps sps mouse mutant displays generalized Absence Seizure-like behavior. In these mice, glutamic acid decarboxylase activity is reduced in the cortex and hippocampus. Tritiated flunitrazepam binding (3H-flu) is reduced in these areas, as well as in midbrain, cerebellum, and pons-medulla. Quantitative [3H]-flunitrazepam binding autoradiography confirms these observations. GABA uptake by synaptosomes from sps sps mice is also reduced in all the areas studied. Potassium-stimulated, Ca2+-dependent release of radioactivity from synaptosomes preloaded with [14C]-GABA is reduced in the hippocampus, increased in midbrain and pons-medulla, but remains unaltered in the cortex. These results suggest region-specific alterations in GABAergic neurotransmission that may be responsible for the Absence-like Seizures in C57BL 10 , sps sps mice.
Gilles Van Luijtelaar - One of the best experts on this subject based on the ideXlab platform.
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methods of automated Absence Seizure detection interference by stimulation and possibilities for prediction in genetic Absence models
Journal of Neuroscience Methods, 2016Co-Authors: Gilles Van Luijtelaar, Annika Luttjohann, Vladimir V Makarov, Vladimir A Maksimenko, A A Koronovskii, A E HramovAbstract:Abstract Background Genetic rat models for childhood Absence epilepsy have become instrumental in developing theories on the origin of Absence epilepsy, the evaluation of new and experimental treatments, as well as in developing new methods for automatic Seizure detection, prediction, and/or interference of Seizures. Method Various methods for automated off and on-line analyses of ECoG in rodent models are reviewed, as well as data on how to interfere with the spike-wave discharges by different types of invasive and non-invasive electrical, magnetic, and optical brain stimulation. Also a new method for Seizure prediction is proposed. Results Many selective and specific methods for off- and on-line spike-wave discharge detection seem excellent, with possibilities to overcome the issue of individual differences. Moreover, electrical deep brain stimulation is rather effective in interrupting ongoing spike-wave discharges with low stimulation intensity. A network based method is proposed for Absence Seizures prediction with a high sensitivity but a low selectivity. Solutions that prevent false alarms, integrated in a closed loop brain stimulation system open the ways for experimental Seizure control. Conclusions The presence of preictal cursor activity detected with state of the art time frequency and network analyses shows that spike-wave discharges are not caused by sudden and abrupt transitions but that there are detectable dynamic events. Their changes in time-space-frequency characteristics might yield new options for Seizure prediction and Seizure control.
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dynamics of networks during Absence Seizure s on and offset in rodents and man
Frontiers in Physiology, 2015Co-Authors: Annika Luttjohann, Gilles Van LuijtelaarAbstract:Network mechanisms relevant for the generation, maintenance and termination of spike-wave discharges (SWD), the neurophysiological hallmark of Absence epilepsy, are still enigmatic and widely discussed. Within the last years, however, improvements in signal analytical techniques, applied to both animal and human fMRI, EEG, MEG, and ECoG data, greatly increased our understanding and challenged several, dogmatic concepts of SWD. This review will summarize these recent data, demonstrating that SWD are not primary generalized, are not sudden and unpredictable events. It will disentangle different functional contributions of structures within the cortico-thalamo-cortical system, relevant for the generation, generalization, maintenance, and termination of SWD and will present a new “network based” scenario for these oscillations. Similarities and differences between rodent and human data are presented demonstrating that in both species a local cortical onset zone of SWD exists, although with different locations; that in both some forms of cortical and thalamic precursor activity can be found, and that SWD occur through repetitive cyclic activity between cortex and thalamus. The focal onset zone in human data could differ between patients with varying spatial and temporal dynamics; in rats the latter is still poorly investigated.
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application of adaptive nonlinear granger causality disclosing network changes before and after Absence Seizure onset in a genetic rat model
Journal of Neuroscience Methods, 2014Co-Authors: M V Sysoeva, Evgenia Sitnikova, I V Sysoev, B P Bezruchko, Gilles Van LuijtelaarAbstract:Abstract Background Advanced methods of signal analysis of the preictal and ictal activity dynamics characterizing Absence epilepsy in humans with Absences and in genetic animal models have revealed new and unknown electroencephalographic characteristics, that has led to new insights and theories. New method Taking into account that some network associations can be considered as nonlinear, an adaptive nonlinear Granger causality approach was developed and applied to analyze cortico-cortical, cortico-thalamic and intrathalamic network interactions from local field potentials (LFPs). The outcomes of adaptive nonlinear models, constructed based on the properties of electroencephalographic signal and on statistical criteria to optimize the number of coefficients in the models, were compared with the outcomes of linear Granger causality. Results The nonlinear adaptive method showed statistically significant preictal changes in Granger causality in almost all pairs of channels, as well as ictal changes in cortico-cortical, cortico-thalamic and intrathalamic networks. Current results suggest rearrangement of interactions in the thalamo-cortical network accompanied the transition from preictal to ictal phase. Comparison with existing method(s) The linear method revealed no preictal and less ictal changes in causality. Conclusions Achieved results suggest that this proposed adaptive nonlinear method is more sensitive than the linear one to dynamics of network properties. Since changes in coupling were found before the Seizure-related increase of LFP signal amplitude and also based on some additional tests it seems likely that they were not spurious and could not result from signal to noise ratio change.
Arnaldo E. Negrón - One of the best experts on this subject based on the ideXlab platform.
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gabaergic neurotransmission in the c57bl 10 sps sps mouse mutant a model of Absence Seizures
Experimental Neurology, 1991Co-Authors: J G Ortiz, Arnaldo E. Negrón, A.p. Thomas, H. Heimer, J. A. Moreira, Mayra L. Cordero, J. Aranda, M. S. BrunoAbstract:Abstract The C57BL 10 , sps sps mouse mutant displays generalized Absence Seizure-like behavior. In these mice, glutamic acid decarboxylase activity is reduced in the cortex and hippocampus. Tritiated flunitrazepam binding (3H-flu) is reduced in these areas, as well as in midbrain, cerebellum, and pons-medulla. Quantitative [3H]-flunitrazepam binding autoradiography confirms these observations. GABA uptake by synaptosomes from sps sps mice is also reduced in all the areas studied. Potassium-stimulated, Ca2+-dependent release of radioactivity from synaptosomes preloaded with [14C]-GABA is reduced in the hippocampus, increased in midbrain and pons-medulla, but remains unaltered in the cortex. These results suggest region-specific alterations in GABAergic neurotransmission that may be responsible for the Absence-like Seizures in C57BL 10 , sps sps mice.
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GABAergic neurotransmission in the C57BL/10 sps/sps mouse mutant: a model of Absence Seizures.
Experimental neurology, 1991Co-Authors: Arnaldo E. Negrón, A.p. Thomas, H. Heimer, J. A. Moreira, Mayra L. Cordero, J. Aranda, M. S. BrunoAbstract:Abstract The C57BL 10 , sps sps mouse mutant displays generalized Absence Seizure-like behavior. In these mice, glutamic acid decarboxylase activity is reduced in the cortex and hippocampus. Tritiated flunitrazepam binding (3H-flu) is reduced in these areas, as well as in midbrain, cerebellum, and pons-medulla. Quantitative [3H]-flunitrazepam binding autoradiography confirms these observations. GABA uptake by synaptosomes from sps sps mice is also reduced in all the areas studied. Potassium-stimulated, Ca2+-dependent release of radioactivity from synaptosomes preloaded with [14C]-GABA is reduced in the hippocampus, increased in midbrain and pons-medulla, but remains unaltered in the cortex. These results suggest region-specific alterations in GABAergic neurotransmission that may be responsible for the Absence-like Seizures in C57BL 10 , sps sps mice.
Gaoxiang Ouyang - One of the best experts on this subject based on the ideXlab platform.
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characterizing dynamics of Absence Seizure eeg with spatial temporal permutation entropy
Neurocomputing, 2018Co-Authors: Ke Zeng, Gaoxiang Ouyang, He Chen, Xianzeng LiuAbstract:Abstract Characterizing transient brain dynamics prior to Seizures is a main challenge in Absence epilepsy study. As brain is a chaos dynamical system, many complexity based methods have been used to track the dynamical changes of Absence Seizure EEG. However, most of these methods treat multichannel EEG recordings as a set of individual time series, which will inevitably lead to the loss of crucial cross-channel correlation in the epileptic network. Recently, a spatial-temporal permutation entropy method called multivariate multiscale permutation entropy (MMPE) was proposed to measure the complexity of multichannel data. In this study, MMPE was applied to multichannel EEG for characterizing dynamics of Absence Seizure. It was found that the pre-ictal EEG exhibited a significant lower MMPE value than interictal EEG, and a significant higher MMPE value than the ictal EEG, indicating that the complexity of multichannel EEG decreased in the transition of brain activities. This finding confirmed the existence of a pre-Seizure state in Absence epilepsy. The identification ability of MMPE was tested against its original univariate complexity measures: permutation entropy (PE) and multiscale permutation entropy (MSPE), and another multivariate multiscale entropy: multivariate multiscale sample entropy (MMSE). After evaluating the performance by four classifiers (Decision Tree, K-Nearest Neighbor, Discriminant Analysis, Support Vector Machine), MMPE can achieve accuracy of 87.2% at least, which is about 15%, 12%, and 10% higher than that of PE, MSPE and MMSE. Hence, this work supports the view that EEG has a detectable change prior to an Absence Seizure, and MMPE could be considered as a candidate precursor of the impending Absence Seizures.
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Order Time Series Analysis of Neural Signals
Signal Processing in Neuroscience, 2016Co-Authors: Gaoxiang Ouyang, Xiaoli LiAbstract:Order time series analysis, a very simple and fast algorithm, is used to track the transient dynamics of electroencephalogram (EEG) recordings during the different Absence Seizure states in Absence Seizure epileptic rats. Permutation entropy, forbidden order patterns (FOP), and dissimilarity index are applied to analyze the EEG data from the Seizure-free, the pre-Seizure, and Seizure phases. The results show that the number of FOPs in pre-Seizure EEG epochs is higher than that in Seizure-free EEG epochs but lower than that in Seizure EEG epochs. Furthermore, we investigate order time series analysis as a tool to detect the pre-Seizure state by using EEG recordings. The results show that order time series analysis can track the dynamical changes of EEG data so as to describe transient dynamics prior to the Absence Seizures.
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Dynamical Similarity Analysis of EEG Recordings
Signal Processing in Neuroscience, 2016Co-Authors: Gaoxiang OuyangAbstract:Electroencephalogram (EEG) recordings contain a large amount of information about physiological and pathological processes in the brain and serve as one of the important tools in clinical diagnosis and research regarding epilepsy. Dynamical similarity analysis is applied to characterize EEG changes in different Absence Seizure states. The average similarity measure of a pair of EEG signals in the same Seizure states and across different Seizure states is calculated using an improved dynamical similarity method. The results show that the average similarity measures between EEG segments within the Seizure-free state are close to 1, suggesting that the EEG segments within the Seizure-free state share the same dynamic characteristics. The similarity measures between EEG segments across different Seizure states are typically smaller, indicating that the changes of dynamic characteristics can be found during different Absence Seizure states.
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using relevance feedback to distinguish the changes in eeg during different Absence Seizure phases
Clinical Eeg and Neuroscience, 2016Co-Authors: Xianzeng Liu, Gaoxiang OuyangAbstract:We carried out a series of statistical experiments to explore the utility of using relevance feedback on electroencephalogram (EEG) data to distinguish between different activity states in human Absence epilepsy. EEG recordings from 10 patients with Absence epilepsy are sampled, filtered, selected, and dissected from Seizure-free, preSeizure, and Seizure phases. A total of 112 two-second 19-channel EEG epochs from 10 patients were selected from each phase. For each epoch, multiscale permutation entropy of the EEG data was calculated. The feature dimensionality was reduced by linear discriminant analysis to obtain a more discriminative and compact representation. Finally, a relevance feedback technique, that is, direct biased discriminant analysis, was applied to 68 randomly selected queries over nine iterations. This study is a first attempt to apply the statistical analysis of relevance feedback to the distinction of different EEG activity states in Absence epilepsy. The average precision in the top 10 returned results was 97.5%, and the standard deviation suggested that embedding relevance feedback can effectively distinguish different Seizure phases in Absence epilepsy. The experimental results indicate that relevance feedback may be an effective tool for the prediction of different activity states in human Absence epilepsy. The simultaneous analysis of multichannel EEG signals provides a powerful tool for the exploration of abnormal electrical brain activity in patients with epilepsy.
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using permutation entropy to measure the changes in eeg signals during Absence Seizures
Entropy, 2014Co-Authors: Jiaqing Yan, Xianzeng Liu, Gaoxiang OuyangAbstract:In this paper, we propose to use permutation entropy to explore whether the changes in electroencephalogram (EEG) data can effectively distinguish different phases in human Absence epilepsy, i.e., the Seizure-free, the pre-Seizure and Seizure phases. Permutation entropy is applied to analyze the EEG data from these three phases, each containing 100 19-channel EEG epochs of 2 s duration. The experimental results show the mean value of PE gradually decreases from the Seizure-free to the Seizure phase and provides evidence that these three different Seizure phases in Absence epilepsy can be effectively distinguished. Furthermore, our results strengthen the view that most frontal electrodes carry useful information and patterns that can help discriminate among different Absence Seizure phases.
H. Heimer - One of the best experts on this subject based on the ideXlab platform.
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gabaergic neurotransmission in the c57bl 10 sps sps mouse mutant a model of Absence Seizures
Experimental Neurology, 1991Co-Authors: J G Ortiz, Arnaldo E. Negrón, A.p. Thomas, H. Heimer, J. A. Moreira, Mayra L. Cordero, J. Aranda, M. S. BrunoAbstract:Abstract The C57BL 10 , sps sps mouse mutant displays generalized Absence Seizure-like behavior. In these mice, glutamic acid decarboxylase activity is reduced in the cortex and hippocampus. Tritiated flunitrazepam binding (3H-flu) is reduced in these areas, as well as in midbrain, cerebellum, and pons-medulla. Quantitative [3H]-flunitrazepam binding autoradiography confirms these observations. GABA uptake by synaptosomes from sps sps mice is also reduced in all the areas studied. Potassium-stimulated, Ca2+-dependent release of radioactivity from synaptosomes preloaded with [14C]-GABA is reduced in the hippocampus, increased in midbrain and pons-medulla, but remains unaltered in the cortex. These results suggest region-specific alterations in GABAergic neurotransmission that may be responsible for the Absence-like Seizures in C57BL 10 , sps sps mice.
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GABAergic neurotransmission in the C57BL/10 sps/sps mouse mutant: a model of Absence Seizures.
Experimental neurology, 1991Co-Authors: Arnaldo E. Negrón, A.p. Thomas, H. Heimer, J. A. Moreira, Mayra L. Cordero, J. Aranda, M. S. BrunoAbstract:Abstract The C57BL 10 , sps sps mouse mutant displays generalized Absence Seizure-like behavior. In these mice, glutamic acid decarboxylase activity is reduced in the cortex and hippocampus. Tritiated flunitrazepam binding (3H-flu) is reduced in these areas, as well as in midbrain, cerebellum, and pons-medulla. Quantitative [3H]-flunitrazepam binding autoradiography confirms these observations. GABA uptake by synaptosomes from sps sps mice is also reduced in all the areas studied. Potassium-stimulated, Ca2+-dependent release of radioactivity from synaptosomes preloaded with [14C]-GABA is reduced in the hippocampus, increased in midbrain and pons-medulla, but remains unaltered in the cortex. These results suggest region-specific alterations in GABAergic neurotransmission that may be responsible for the Absence-like Seizures in C57BL 10 , sps sps mice.
