1
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Dervinis M, Crunelli V. Spike-and-wave discharges of absence seizures in a sleep waves-constrained corticothalamic model. CNS Neurosci Ther 2024; 30:e14204. [PMID: 37032628 PMCID: PMC10915988 DOI: 10.1111/cns.14204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 03/18/2023] [Accepted: 03/24/2023] [Indexed: 04/11/2023] Open
Abstract
AIMS Recurrent network activity in corticothalamic circuits generates physiological and pathological EEG waves. Many computer models have simulated spike-and-wave discharges (SWDs), the EEG hallmark of absence seizures (ASs). However, these models either provided detailed simulated activity only in a selected territory (i.e., cortical or thalamic) or did not test whether their corticothalamic networks could reproduce the physiological activities that are generated by these circuits. METHODS Using a biophysical large-scale corticothalamic model that reproduces the full extent of EEG sleep waves, including sleep spindles, delta, and slow (<1 Hz) waves, here we investigated how single abnormalities in voltage- or transmitter-gated channels in the neocortex or thalamus led to SWDs. RESULTS We found that a selective increase in the tonic γ-aminobutyric acid type A receptor (GABA-A) inhibition of first-order thalamocortical (TC) neurons or a selective decrease in cortical phasic GABA-A inhibition is sufficient to generate ~4 Hz SWDs (as in humans) that invariably start in neocortical territories. Decreasing the leak conductance of higher-order TC neurons leads to ~7 Hz SWDs (as in rodent models) while maintaining sleep spindles at 7-14 Hz. CONCLUSION By challenging key features of current mechanistic views, this simulated ictal corticothalamic activity provides novel understanding of ASs and makes key testable predictions.
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Affiliation(s)
- Martynas Dervinis
- Neuroscience Division, School of BioscienceCardiff UniversityMuseum AvenueCardiffCF10 3AXUK
- Present address:
School of Physiology, Pharmacology and NeuroscienceBiomedical BuildingBristolBS8 1TDUK
| | - Vincenzo Crunelli
- Neuroscience Division, School of BioscienceCardiff UniversityMuseum AvenueCardiffCF10 3AXUK
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2
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Zhao J, Yu Y, Han F, Wang Q. Regulating epileptiform discharges by heterogeneous interneurons in thalamocortical model. CHAOS (WOODBURY, N.Y.) 2023; 33:083128. [PMID: 37561121 DOI: 10.1063/5.0163243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 07/25/2023] [Indexed: 08/11/2023]
Abstract
Inhibitory interneurons in the cortex are abundant and have diverse roles, classified as parvalbumin (PV), somatostatin (SOM), and vasoactive intestinal polypeptide (VIP) according to chemically defined categories. Currently, their involvement with seizures has been partially uncovered in physiological terms. Here, we propose a corticothalamic model containing heterogeneous interneurons to study the effects of various interneurons on absence seizure dynamics by means of optogenetic stimulation. First, the important role of feedforward inhibition caused by SRN→PV→PN projections on seizures is verified. Then, we demonstrate that light activation targeting either PV or SOM INs can control seizures. Finally, with different inhibition contributions from PV INs and SOM INs, the possible disinhibitory effect of blue light acting on VIP INs is mainly discussed. The results suggest that depending on the inhibition degree of both types, the disinhibition brought about by the VIP INs will trigger seizures, will control seizures, and will not work or cause the PNs to tend toward a high saturation state with high excitability. The circuit mechanism and the related bifurcation characteristics in various cases are emphatically revealed. In the model presented, in addition to Hopf and saddle-node bifurcations, the system may also undergo period-doubling and torus bifurcations under stimulus action, with more complex dynamics. Our work may provide a theoretical basis for understanding and further exploring the role of heterogeneous interneurons, in particular, the VIP INs, a novel target, in absence seizures.
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Affiliation(s)
- Jinyi Zhao
- Department of Dynamics and Control, Beihang University, Beijing 100191, China
| | - Ying Yu
- School of Engineering Medicine, Beihang University, Beijing 100191, China
| | - Fang Han
- College of Information Science and Technology, Donghua University, Shanghai 201620, China
| | - Qingyun Wang
- Department of Dynamics and Control, Beihang University, Beijing 100191, China
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3
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Fontes-Dutra M, Righes Marafiga J, Santos-Terra J, Deckmann I, Brum Schwingel G, Rabelo B, Kazmierzak de Moraes R, Rockenbach M, Vendramin Pasquetti M, Gottfried C, Calcagnotto ME. GABAergic synaptic transmission and cortical oscillation patterns in the primary somatosensory area of a valproic acid rat model of autism spectrum disorder. Eur J Neurosci 2023; 57:527-546. [PMID: 36504470 DOI: 10.1111/ejn.15893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 11/20/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022]
Abstract
Autism spectrum disorder (ASD) is characterized by impaired social communication and interaction associated with repetitive or stereotyped behaviour. Prenatal valproic acid (VPA) exposure in rodents is a commonly used model of ASD. Resveratrol (RSV) has been shown to prevent interneuronal and behavioural impairments in the VPA model. We investigated the effects of prenatal VPA exposure and RSV on the GABAergic synaptic transmission, brain oscillations and on the genic expression of interneuron-associated transcription factor LHX6 in the primary somatosensory area (PSSA). Prenatal VPA exposure decreased the sIPSC and mIPSC frequencies and the sIPSC decay kinetics onto layers 4/5 pyramidal cells of PSSA. About 40% of VPA animals exhibited absence-like spike-wave discharge (SWD) events associated with behaviour arrest and increased power spectrum density of delta, beta and gamma cortical oscillations. VPA animals had reduced LHX6 expression in PSSA, but VPA animals treated with RSV had no changes on synaptic inhibition or LHX6 expression in the PSSA. SWD events associated with behaviour arrest and the abnormal increment of cortical oscillations were also absent in VPA animals treated with RSV. These findings provide new venues to investigate the role of both RSV and VPA in the pathophysiology of ASD and highlight the VPA animal model as an interesting tool to investigate pathways related to the aetiology and possible future therapies to this neuropsychiatric disorder.
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Affiliation(s)
- Mellanie Fontes-Dutra
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Joseane Righes Marafiga
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Graduate Program in Biological Science: Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory, Department of Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Júlio Santos-Terra
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Iohanna Deckmann
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Gustavo Brum Schwingel
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Bruna Rabelo
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Rafael Kazmierzak de Moraes
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Marília Rockenbach
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Mayara Vendramin Pasquetti
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Graduate Program in Biological Science: Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory, Department of Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Carmem Gottfried
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Maria Elisa Calcagnotto
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Graduate Program in Biological Science: Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory, Department of Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Graduate Program in Neuroscience, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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4
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Li J, Feng P, Zhao L, Chen J, Du M, Song J, Wu Y. Transition behavior of the seizure dynamics modulated by the astrocyte inositol triphosphate noise. CHAOS (WOODBURY, N.Y.) 2022; 32:113121. [PMID: 36456345 DOI: 10.1063/5.0124123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 10/17/2022] [Indexed: 06/17/2023]
Abstract
Epilepsy is a neurological disorder with recurrent seizures, which convey complex dynamical characteristics including chaos and randomness. Until now, the underlying mechanism has not been fully elucidated, especially the bistable property beneath the epileptic random induction phenomena in certain conditions. Inspired by the recent finding that astrocyte GTPase-activating protein (G-protein)-coupled receptors could be involved in stochastic epileptic seizures, we proposed a neuron-astrocyte network model, incorporating the noise of the astrocytic second messenger, inositol triphosphate (IP3) that is modulated by G-protein-coupled receptor activation. Based on this model, we have statistically analyzed the transitions of epileptic seizures by performing repeatable simulation trials. Our simulation results show that the increase in the IP3 noise intensity induces depolarization-block epileptic seizures together with an increase in neuronal firing frequency, consistent with corresponding experiments. Meanwhile, the bistable states of the seizure dynamics were present under certain noise intensities, during which the neuronal firing pattern switches between regular sparse spiking and epileptic seizure states. This random presence of epileptic seizures is absent when the noise intensity continues to increase, accompanying with an increase in the epileptic depolarization block duration. The simulation results also shed light on the fact that calcium signals in astrocytes play significant roles in the pattern formations of the epileptic seizure. Our results provide a potential pathway for understanding the epileptic randomness in certain conditions.
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Affiliation(s)
- Jiajia Li
- College of Information and Control Engineering, Xi'an University of Architecture and Technology, Shaanxi, Xi'an 710055, China
| | - Peihua Feng
- State Key Laboratory for Strength and Vibration of Mechanical Structures, National Demonstration Center for Experimental Mechanics Education, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Liang Zhao
- College of Information and Control Engineering, Xi'an University of Architecture and Technology, Shaanxi, Xi'an 710055, China
| | - Junying Chen
- College of Information and Control Engineering, Xi'an University of Architecture and Technology, Shaanxi, Xi'an 710055, China
| | - Mengmeng Du
- School of Mathematics and Data Science, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Jian Song
- Department of Neurosurgery, Wuhan General Hospital of PLA, Wuhan 430070, China
| | - Ying Wu
- State Key Laboratory for Strength and Vibration of Mechanical Structures, National Demonstration Center for Experimental Mechanics Education, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China
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5
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Pan Y, Zhang H, Xie Y, Chai Y. Role of coupling distances in a coupled thalamocortical network for regulation of epilepsy. J Theor Biol 2022; 550:111206. [PMID: 35850254 DOI: 10.1016/j.jtbi.2022.111206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 04/24/2022] [Accepted: 06/20/2022] [Indexed: 11/17/2022]
Abstract
The recent theoretical modeling of coupled cortical thalamic network is an important advance toward the spatiotemporal dynamics of the brain. However, the diversity of coupling distances is ignored, and the better choice of deep brain stimulation (DBS) parameters to control epilepsy is still a challenge so far. A modeling object of this paper is to establish a coupled cortical thalamic model with uncertain coupling distances including nine combinations. Based on the pathways formed by pyramidal neuronal population (PY), thalamic reticular nucleus (RE) and thalamic relay nucleus (TC), we simulate the spike-wave discharges (SWD) at 2-4Hz which are the main manifestations of absence episodes. It is demonstrated that combination (1/3, 1/9) between the left and right ventricles is the optimal coupling distance of the proposed model by analyzing the percentage of SWD. A stimulating object of this paper is to find an optimum parameter range of DBS. One of the important results is that the number of SWD is inversely proportional to the amplitude, another one is that the number of SWD shows a U-shaped trend with the change of frequency. The present study has laidtheoryfoundationforthebrainplasticity, which will provide an important theoretical basis and direction for the treatment of absence epilepsy in the future. In brief, hopefully our simulation results will provide some help to patients.
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Affiliation(s)
- Yufeng Pan
- School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 201306, China
| | - Hudong Zhang
- School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 201306, China
| | - Yan Xie
- School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 201306, China
| | - Yuan Chai
- School of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 201306, China.
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6
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Almeida CGM, Costa-Higuchi K, Piovesan AR, Moro CF, Venturin GT, Greggio S, Costa-Ferro ZS, Salamoni SD, Peigneur S, Tytgat J, de Lima ME, Silva CND, Vinadé L, Rowan EG, DaCosta JC, Dal Belo CA, Carlini CR. Neurotoxic and convulsant effects induced by jack bean ureases on the mammalian nervous system. Toxicology 2021; 454:152737. [PMID: 33631299 DOI: 10.1016/j.tox.2021.152737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/18/2021] [Accepted: 02/20/2021] [Indexed: 12/14/2022]
Abstract
Ureases are microbial virulence factors either because of the enzymatic release of ammonia or due to many other non-enzymatic effects. Here we studied two neurotoxic urease isoforms, Canatoxin (CNTX) and Jack Bean Urease (JBU), produced by the plant Canavalia ensiformis, whose mechanisms of action remain elusive. The neurotoxins provoke convulsions in rodents (LD50 ∼2 mg/kg) and stimulate exocytosis in cell models, affecting intracellular calcium levels. Here, electrophysiological and brain imaging techniques were applied to elucidate their mode of action. While systemic administration of the toxins causes tonic-clonic seizures in rodents, JBU injected into rat hippocampus induced spike-wave discharges similar to absence-like seizures. JBU reduced the amplitude of compound action potential from mouse sciatic nerve in a tetrodotoxin-insensitive manner. Hippocampal slices from CNTX-injected animals or slices treated in vitro with JBU failed to induce long term potentiation upon tetanic stimulation. Rat cortical synaptosomes treated with JBU released L-glutamate. JBU increased the intracellular calcium levels and spontaneous firing rate in rat hippocampus neurons. MicroPET scans of CNTX-injected rats revealed increased [18]Fluoro-deoxyglucose uptake in epileptogenesis-related areas like hippocampus and thalamus. Curiously, CNTX did not affect voltage-gated sodium, calcium or potassium channels currents, neither did it interfere on cholinergic receptors, suggesting an indirect mode of action that could be related to the ureases' membrane-disturbing properties. Understanding the neurotoxic mode of action of C. ensiformis ureases could help to unveil the so far underappreciated relevance of these toxins in diseases caused by urease-producing microorganisms, in which the human central nervous system is affected.
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Affiliation(s)
- Carlos Gabriel Moreira Almeida
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Medicine and Health Sciences, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Kiyo Costa-Higuchi
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Materials Technology and Engineering, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Angela Regina Piovesan
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Celular and Molecular Biology, Center of Biotechnology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Carlo Frederico Moro
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Medicine and Health Sciences, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Gianina Teribele Venturin
- Preclinical Research Center, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Samuel Greggio
- Preclinical Research Center, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Zaquer Susana Costa-Ferro
- Laboratory of Neuroscience, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Simone Denise Salamoni
- Laboratory of Neuroscience, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Steve Peigneur
- Laboratory of Toxicology & Pharmacology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Jan Tytgat
- Laboratory of Toxicology & Pharmacology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Maria Elena de Lima
- Institute of Teaching and Research, Santa Casa de Belo Horizonte, Belo Horizonte, MG, Brazil
| | | | - Lúcia Vinadé
- Laboratory of Neurobiology and Toxinology (Lanetox), Universidade Federal do Pampa, São Gabriel, RS, Brazil
| | - Edward G Rowan
- Strathclyde Institute for Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Jaderson Costa DaCosta
- Laboratory of Neuroscience, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Cháriston André Dal Belo
- Laboratory of Neurobiology and Toxinology (Lanetox), Universidade Federal do Pampa, São Gabriel, RS, Brazil.
| | - Celia Regina Carlini
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Medicine and Health Sciences, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Scholl of Medicine, Pontificía Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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7
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Yan L, Zhang H, Sun Z, Shen Z. Control analysis of electrical stimulation for epilepsy waveforms in a thalamocortical network. J Theor Biol 2020; 504:110391. [PMID: 32640272 DOI: 10.1016/j.jtbi.2020.110391] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 06/20/2020] [Accepted: 06/24/2020] [Indexed: 11/28/2022]
Abstract
Physiological experiments and computational models both show that the thalamic reticular nucleus (RE) participates in inducing various firing patterns of cortex. Absence seizure, featured by 2-4 Hz spike-wave discharges (SWD) oscillation, is a high incidence of disease in children. Lots of electrophysiological experiments have verified the correlation between absence seizures and RE, however, the dynamical mechanisms are not well understood. Based on previous Taylor model, we firstly study the effects of external input and self-inhibition of RE on epilepsy transition. We show that increasing external input and self-inhibition of RE can lead the system from epileptic state to normal state, and vice versa. Next, we explore two stimulus strategies added in RE and various transition behaviors can be induced, such as high saturated state to clonic. Meanwhile, as the intensity of stimulation increasing, they can not only suppress the SWD, but also produce tonic-clonic oscillation. Finally, the control of DBS on single neuron cluster and two neuron clusters are compared and we find stimulating RE and TC simultaneously is a superior mode to stimulate anyone of RE or TC. It is hoped that the results we obtained will have an enlightenment on clinical treatment.
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Affiliation(s)
- Luyao Yan
- School of Mathematics and Statistics, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Honghui Zhang
- School of Mathematics and Statistics, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
| | - Zhongkui Sun
- School of Mathematics and Statistics, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China.
| | - Zhuan Shen
- School of Mathematics and Statistics, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China
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Abstract
The progressive myoclonic epilepsies (PMEs) represent a rare but devastating group of syndromes characterized by epileptic myoclonus, typically action-induced seizures, neurological regression, medically refractory epilepsy, and a variety of other signs and symptoms depending on the specific syndrome. Most of the PMEs begin in children who are developing as expected, with the onset of the disorder heralded by myoclonic and other seizure types. The conditions are considerably heterogenous, but medical intractability to epilepsy, particularly myoclonic seizures, is a core feature. With the increasing use of molecular genetic techniques, mutations and their abnormal protein products are being delineated, providing a basis for disease-based therapy. However, genetic and enzyme replacement or substrate removal are in the nascent stage, and the primary therapy is through antiepileptic drugs. Epilepsy in children with progressive myoclonic seizures is notoriously difficult to treat. The disorder is rare, so few double-blinded, placebo-controlled trials have been conducted in PME, and drugs are chosen based on small open-label trials or extrapolation of data from drug trials of other syndromes with myoclonic seizures. This review discusses the major PME syndromes and their neurogenetic basis, pathophysiological underpinning, electroencephalographic features, and currently available treatments.
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Affiliation(s)
- Gregory L Holmes
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont College of Medicine, Stafford Hall, 118C, Burlington, VT, 05405, USA.
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9
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Li X, Yang X, Sun Z. Alpha rhythm slowing in a modified thalamo-cortico-thalamic model related with Alzheimer's disease. PLoS One 2020; 15:e0229950. [PMID: 32163454 PMCID: PMC7067465 DOI: 10.1371/journal.pone.0229950] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 02/18/2020] [Indexed: 12/21/2022] Open
Abstract
A decrease in alpha band power is defined as a hallmark of electroencephalogram (EEG) in Alzheimer’s disease (AD). This study devotes to understanding the neuronal correlates of alpha rhythm slowing associated with AD from the view of neurocomputation. Firstly, a modified computational model of thalamo-cortico-thalamic (TCT) circuitry is constructed by incorporating two important biologically plausible ingredients. One is the disinhibition property between different inhibitory interneurons in the cortical module. The other is the full relay function of thalamic relay nucleus (TCR) to the cortical module. Then, by decreasing synaptic connectivity parameters to mimic the neuropathological condition of synapse loss in AD, the correlation between neuronal synaptic behavior and abnormal alpha rhythm is simulated by means of power spectral analysis. The results indicate that these decreases of synaptic activity, i.e., not only the excitatory synaptic connections from TCR to fast inhibitory interneurons Cfte and from excitatory interneurons to pyramidal neurons Cpxe but also the inhibitory synaptic connections from fast inhibitory interneurons to slow inhibitory interneurons Clfi and from inhibitory interneurons to TCR Ctii, can significantly diminish the peak power density over the alpha band of the thalamic output, which implies that there is a slowing of alpha band. Furthermore, the underlying mechanism behind the alpha rhythmic changes is analyzed using nonlinear dynamical technique. The results reveal that decreases of Cfte, Cpxe, Clfi and Ctii can make the thalamic module transfer from a limit cycle mode to a point attractor mode, which may lead to the alpha rhythm slowing in the modified TCT model. We expect this work can be helpful in identifying early biomarkers of AD’s EEG and understanding potential pathogenesis of AD.
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Affiliation(s)
- XiaoYuan Li
- College of Mathematics and Information Science, Shaanxi Normal University, Xi’an, PR China
| | - XiaoLi Yang
- College of Mathematics and Information Science, Shaanxi Normal University, Xi’an, PR China
- * E-mail:
| | - ZhongKui Sun
- Department of Applied Mathematics, Northwestern Polytechnical University, Xi’an, PR China
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10
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Arkun Y. Detection of biological switches using the method of Gröebner bases. BMC Bioinformatics 2019; 20:615. [PMID: 31779580 PMCID: PMC6883700 DOI: 10.1186/s12859-019-3155-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 10/14/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bistability and ability to switch between two stable states is the hallmark of cellular responses. Cellular signaling pathways often contain bistable switches that regulate the transmission of the extracellular information to the nucleus where important biological functions are executed. RESULTS In this work we show how the method of Gröebner bases can be used to detect bistability and output switchability. The method of Gröebner bases can be seen as a multivariate, non-linear generalization of the Gaussian elimination for linear systems which conveniently seperates the variables and drastically simplifies the simultaneous solution of polynomial equations. A necessary condition for fixed-point state bistability is for the Gröbner basis to have three distinct solutions for the state. A sufficient condition is provided by the eigenvalues of the local Jacobians. We also introduce the concept of output switchability which is defined as the ability of an output of a bistable system to switch between two different stable steady-state values. It is shown that bistability does not necessarily guarantee switchability of every state variable of the system. We further show that, for a bistable system, the necessary conditions for output switchability can be derived using the Gröebner basis. The theoretical results are incorporated into an analysis procedure and applied to several systems including the AKT (Protein kinase B), RAS (Rat Sarcoma) and MAPK (Mitogen-activated protein kinase) signal transduction pathways. Results demonstrate that the Gröebner bases can be conveniently used to analyze biological switches by simultaneously detecting bistability and output switchability. CONCLUSION The Gröebner bases provides a novel methodology to analyze bistability. Results clarify the distinction between bistability and output switchability which is lacking in the literature. We have shown that theoretically, it is possible to have an output subspace of an n-dimensional bistable system where certain variables cannot switch. It is possible to construct such systems as we have done with two reaction networks.
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Affiliation(s)
- Yaman Arkun
- Department of Chemical and Biological Engineering, Koc University, Rumeli Feneri Yolu, 34450, Sariyer, Istanbul, Turkey.
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11
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Ge Y, Cao Y, Yi G, Han C, Qin Y, Wang J, Che Y. Robust closed-loop control of spike-and-wave discharges in a thalamocortical computational model of absence epilepsy. Sci Rep 2019; 9:9093. [PMID: 31235838 PMCID: PMC6591255 DOI: 10.1038/s41598-019-45639-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 06/07/2019] [Indexed: 01/24/2023] Open
Abstract
In this paper, we investigate the abatement of spike-and-wave discharges in a thalamocortical model using a closed-loop brain stimulation method. We first explore the complex states and various transitions in the thalamocortical computational model of absence epilepsy by using bifurcation analysis. We demonstrate that the Hopf and double cycle bifurcations are the key dynamical mechanisms of the experimental observed bidirectional communications during absence seizures through top-down cortical excitation and thalamic feedforward inhibition. Then, we formulate the abatement of epileptic seizures to a closed-loop tracking control problem. Finally, we propose a neural network based sliding mode feedback control system to drive the dynamics of pathological cortical area to track the desired normal background activities. The control system is robust to uncertainties and disturbances, and its stability is guaranteed by Lyapunov stability theorem. Our results suggest that the seizure abatement can be modeled as a tracking control problem and solved by a robust closed-loop control method, which provides a promising brain stimulation strategy.
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Affiliation(s)
- Yafang Ge
- School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, P. R. China
| | - Yuzhen Cao
- School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, 300072, P. R. China
| | - Guosheng Yi
- School of Electrical and Information Engineering, Tianjin University, Tianjin, 300072, P. R. China
| | - Chunxiao Han
- Tianjin Key Laboratory of Information Sensing & Intelligent Control, School of Automation and Electrical Engineering, Tianjin University of Technology and Education, Tianjin, 300222, P. R. China.
| | - Yingmei Qin
- Tianjin Key Laboratory of Information Sensing & Intelligent Control, School of Automation and Electrical Engineering, Tianjin University of Technology and Education, Tianjin, 300222, P. R. China
| | - Jiang Wang
- School of Electrical and Information Engineering, Tianjin University, Tianjin, 300072, P. R. China.
| | - Yanqiu Che
- Department of Neurosurgery, Penn State College of Medicine, Hershey, PA, 17033, USA. .,Center for Neural Engineering, Penn State, University Park, PA, 16802, USA.
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12
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Outgrowing seizures in Childhood Absence Epilepsy: time delays and bistability. J Comput Neurosci 2019; 46:197-209. [PMID: 30737596 DOI: 10.1007/s10827-019-00711-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 12/14/2018] [Accepted: 01/29/2019] [Indexed: 10/27/2022]
Abstract
We formulate a conductance-based model for a 3-neuron motif associated with Childhood Absence Epilepsy (CAE). The motif consists of neurons from the thalamic relay (TC) and reticular nuclei (RT) and the cortex (CT). We focus on a genetic defect common to the mouse homolog of CAE which is associated with loss of GABAA receptors on the TC neuron, and the fact that myelination of axons as children age can increase the conduction velocity between neurons. We show the combination of low GABAA mediated inhibition of TC neurons and the long corticothalamic loop delay gives rise to a variety of complex dynamics in the motif, including bistability. This bistability disappears as the corticothalamic conduction delay shortens even though GABAA activity remains impaired. Thus the combination of deficient GABAA activity and changing axonal myelination in the corticothalamic loop may be sufficient to account for the clinical course of CAE.
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13
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Sinha N, Wang Y, Dauwels J, Kaiser M, Thesen T, Forsyth R, Taylor PN. Computer modelling of connectivity change suggests epileptogenesis mechanisms in idiopathic generalised epilepsy. NEUROIMAGE-CLINICAL 2019; 21:101655. [PMID: 30685702 PMCID: PMC6356007 DOI: 10.1016/j.nicl.2019.101655] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 12/21/2018] [Accepted: 01/03/2019] [Indexed: 12/14/2022]
Abstract
Patients with idiopathic generalised epilepsy (IGE) typically have normal conventional magnetic resonance imaging (MRI), hence diagnosis based on MRI is challenging. Anatomical abnormalities underlying brain dysfunctions in IGE are unclear and their relation to the pathomechanisms of epileptogenesis is poorly understood. In this study, we applied connectometry, an advanced quantitative neuroimaging technique for investigating localised changes in white-matter tissues in vivo. Analysing white matter structures of 32 subjects we incorporated our in vivo findings in a computational model of seizure dynamics to suggest a plausible mechanism of epileptogenesis. Patients with IGE have significant bilateral alterations in major white-matter fascicles. In the cingulum, fornix, and superior longitudinal fasciculus, tract integrity is compromised, whereas in specific parts of tracts between thalamus and the precentral gyrus, tract integrity is enhanced in patients. Combining these alterations in a logistic regression model, we computed the decision boundary that discriminated patients and controls. The computational model, informed with the findings on the tract abnormalities, specifically highlighted the importance of enhanced cortico-reticular connections along with impaired cortico-cortical connections in inducing pathological seizure-like dynamics. We emphasise taking directionality of brain connectivity into consideration towards understanding the pathological mechanisms; this is possible by combining neuroimaging and computational modelling. Our imaging evidence of structural alterations suggest the loss of cortico-cortical and enhancement of cortico-thalamic fibre integrity in IGE. We further suggest that impaired connectivity from cortical regions to the thalamic reticular nucleus offers a therapeutic target for selectively modifying the brain circuit for reversing the mechanisms leading to epileptogenesis. Significant focal alterations along major white-matter fascicles in IGE patients are characterised. Increased white matter integrity found in thalamo-cortical connections. Decreased white matter integrity found in cortico-cortical connections. Disease mechanism is investigated by combining the neuroimaging findings with a dynamical model of seizure activity. Model implicates cortical projections to the thalamic reticular nucleus in IGE.
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Affiliation(s)
- Nishant Sinha
- Institute of Neuroscience, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; Interdisciplinary Computing and Complex BioSystems Group, School of Computing, Newcastle University, Newcastle upon Tyne, UK.
| | - Yujiang Wang
- Institute of Neuroscience, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; Interdisciplinary Computing and Complex BioSystems Group, School of Computing, Newcastle University, Newcastle upon Tyne, UK; Institute of Neurology, University College London, UK
| | - Justin Dauwels
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore
| | - Marcus Kaiser
- Institute of Neuroscience, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; Interdisciplinary Computing and Complex BioSystems Group, School of Computing, Newcastle University, Newcastle upon Tyne, UK
| | - Thomas Thesen
- Department of Neurology, School of Medicine, New York University, NY, USA; Department of Physiology and Neuroscience, St. Georges University, Grenada, West Indies
| | - Rob Forsyth
- Institute of Neuroscience, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Peter Neal Taylor
- Institute of Neuroscience, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK; Interdisciplinary Computing and Complex BioSystems Group, School of Computing, Newcastle University, Newcastle upon Tyne, UK; Institute of Neurology, University College London, UK.
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14
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Zhang L, Fan D, Wang Q, Baier G. Effects of brain-derived neurotrophic factor and noise on transitions in temporal lobe epilepsy in a hippocampal network. CHAOS (WOODBURY, N.Y.) 2018; 28:106322. [PMID: 30384669 DOI: 10.1063/1.5036690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 09/19/2018] [Indexed: 06/08/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) has recently been implicated in the modulation of receptor activation leading to dynamic state transitions in temporal lobe epilepsy (TLE). In addition, the crucial role of neuronal noise in these transitions has been studied in electrophysiological experiments. However, the precise role of these factors during seizure generation in TLE is not known. Building on a previously proposed model of an epileptogenic hippocampal network, we included the actions of BDNF-regulated receptors and intrinsic noise. We found that the effects of both BDNF and noise can increase the activation of N-methyl-D-aspartate receptors leading to excessive C a 2 + flux, which induces abnormal fast spiking and bursting. Our results indicate that the combined effects have a strong influence on the seizure-generating network, resulting in higher firing frequency and amplitude. As correlations between firing increase, the synchronization of the entire network increases, a marker of the ictogenic transitions from normal to seizures-like dynamics. Our work on the effects of BDNF dynamics in a noisy environment might lead to an improved model-based understanding of the pathological mechanisms in TLE.
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Affiliation(s)
- Liyuan Zhang
- Department of Dynamics and Control, Beihang University, 100191 Beijing, China
| | - Denggui Fan
- School of Mathematics and Physics, University of Science and Technology Beijing, 100083 Beijing, China
| | - Qingyun Wang
- Department of Dynamics and Control, Beihang University, 100191 Beijing, China
| | - Gerold Baier
- Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
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15
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Sohanian Haghighi H, Markazi AHD. A new description of epileptic seizures based on dynamic analysis of a thalamocortical model. Sci Rep 2017; 7:13615. [PMID: 29051507 PMCID: PMC5648785 DOI: 10.1038/s41598-017-13126-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 09/13/2017] [Indexed: 12/11/2022] Open
Abstract
Increasing evidence suggests that the brain dynamics can be interpreted from the viewpoint of nonlinear dynamical systems. The aim of this paper is to investigate the behavior of a thalamocortical model from this perspective. The model includes both cortical and sensory inputs that can affect the dynamic nature of the model. Driving response of the model subjected to various harmonic stimulations is considered to identify the effects of stimulus parameters on the cortical output. Detailed numerical studies including phase portraits, Poincare maps and bifurcation diagrams reveal a wide range of complex dynamics including period doubling and chaos in the output. Transition between different states can occur as the stimulation parameters are changed. In addition, the amplitude jump phenomena and hysteresis are shown to be possible as a result of the bending in the frequency response curve. These results suggest that the jump phenomenon due to the brain nonlinear resonance can be responsible for the transitions between ictal and interictal states.
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Affiliation(s)
- H Sohanian Haghighi
- School of Mechanical Engineering, Iran University of Science and Technology, Tehran, 16844, Iran.
| | - A H D Markazi
- School of Mechanical Engineering, Iran University of Science and Technology, Tehran, 16844, Iran
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16
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Fan D, Duan L, Wang Q, Luan G. Combined Effects of Feedforward Inhibition and Excitation in Thalamocortical Circuit on the Transitions of Epileptic Seizures. Front Comput Neurosci 2017; 11:59. [PMID: 28736520 PMCID: PMC5500624 DOI: 10.3389/fncom.2017.00059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 06/22/2017] [Indexed: 11/21/2022] Open
Abstract
The mechanisms underlying electrophysiologically observed two-way transitions between absence and tonic-clonic epileptic seizures in cerebral cortex remain unknown. The interplay within thalamocortical network is believed to give rise to these epileptic multiple modes of activity and transitions between them. In particular, it is thought that in some areas of cortex there exists feedforward inhibition from specific relay nucleus of thalamus (TC) to inhibitory neuronal population (IN) which has even more stronger functions on cortical activities than the known feedforward excitation from TC to excitatory neuronal population (EX). Inspired by this, we proposed a modified computational model by introducing feedforward inhibitory connectivity within thalamocortical circuit, to systematically investigate the combined effects of feedforward inhibition and excitation on transitions of epileptic seizures. We first found that the feedforward excitation can induce the transition from tonic oscillation to spike and wave discharges (SWD) in cortex, i.e., the epileptic tonic-absence seizures, with the fixed weak feedforward inhibition. Thereinto, the phase of absence seizures corresponding to strong feedforward excitation can be further transformed into the clonic oscillations with the increasing of feedforward inhibition, representing the epileptic absence-clonic seizures. We also observed the other fascinating dynamical states, such as periodic 2/3/4-spike and wave discharges, reversed SWD and clonic oscillations, as well as saturated firings. More importantly, we can identify the stable parameter regions representing the tonic-clonic oscillations and SWD discharges of epileptic seizures on the 2-D plane composed of feedforward inhibition and excitation, where the physiologically plausible transition pathways between tonic-clonic and absence seizures can be figured out. These results indicate the functional role of feedforward pathways in controlling epileptic seizures and the modified thalamocortical model may provide a guide for future efforts to mechanistically link feedforward pathways in the pathogenesis of epileptic seizures.
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Affiliation(s)
- Denggui Fan
- School of Mathematics and Physics, University of Science and Technology BeijingBeijing, China
- Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, University of Science and Technology BeijingBeijing, China
- Beijing Key Laboratory of Knowledge Engineering for Materials Science, University of Science and Technology BeijingBeijing, China
| | - Lixia Duan
- School of Science, North China University of TechnologyBeijing, China
| | - Qian Wang
- Beijing Key Laboratory of Epilepsy, Epilepsy Center, Department of Functional Neurosurgery, Sanbo Brain Hospital, Capital Medical UniversityBeijing, China
| | - Guoming Luan
- Beijing Key Laboratory of Epilepsy, Epilepsy Center, Department of Functional Neurosurgery, Sanbo Brain Hospital, Capital Medical UniversityBeijing, China
- Beijing Institute for Brain DisordersBeijing, China
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17
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Fan D, Liao F, Wang Q. The pacemaker role of thalamic reticular nucleus in controlling spike-wave discharges and spindles. CHAOS (WOODBURY, N.Y.) 2017; 27:073103. [PMID: 28764392 DOI: 10.1063/1.4991869] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Absence epilepsy, characterized by 2-4 Hz spike-wave discharges (SWDs), can be caused by pathological interactions within the thalamocortical system. Cortical spindling oscillations are also demonstrated to involve the oscillatory thalamocortical rhythms generated by the synaptic circuitry of the thalamus and cortex. This implies that SWDs and spindling oscillations can share the common thalamocortical mechanism. Additionally, the thalamic reticular nucleus (RE) is hypothesized to regulate the onsets and propagations of both the epileptic SWDs and sleep spindles. Based on the proposed single-compartment thalamocortical neural field model, we firstly investigate the stimulation effect of RE on the initiations, terminations, and transitions of SWDs. It is shown that the activations and deactivations of RE triggered by single-pulse stimuli can drive the cortical subsystem to behave as the experimentally observed onsets and self-abatements of SWDs, as well as the transitions from 2-spike and wave discharges (2-SWDs) to SWDs. In particular, with increasing inhibition from RE to the specific relay nucleus (TC), rich transition behaviors in cortex can be obtained through the upstream projection path, RE→TC→Cortex. Although some of the complex dynamical patterns can be expected from the earlier single compartment thalamocortical model, the effect of brain network topology on the emergence of SWDs and spindles, as well as the transitions between them, has not been fully investigated. We thereby develop a spatially extended 3-compartment coupled network model with open-/closed-end connective configurations, to investigate the spatiotemporal effect of RE on the SWDs and spindles. Results show that the degrees of activations of RE1 can induce the rich spatiotemporal evolution properties including the propagations from SWDs to spindles within different compartments and the transitions between them, through the RE1→TC1→Cortex1 and Cortex1→Cortex2→Cortex3 projecting paths, respectively. Overall, those results imply that RE possesses the pacemaker function in controlling SWDs and spindling oscillations, which computationally provide causal support for the involvement of RE in absence seizures and sleep spindles.
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Affiliation(s)
- Denggui Fan
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Fucheng Liao
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Qingyun Wang
- Department of Dynamics and Control, Beihang University, Beijing 100191, People's Republic of China
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18
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Ahn S, Jo S, Jun SB, Lee HW, Lee S. Prediction of the Seizure Suppression Effect by Electrical Stimulation via a Computational Modeling Approach. Front Comput Neurosci 2017; 11:39. [PMID: 28611617 PMCID: PMC5447012 DOI: 10.3389/fncom.2017.00039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 05/08/2017] [Indexed: 11/13/2022] Open
Abstract
In this paper, we identified factors that can affect seizure suppression via electrical stimulation by an integrative study based on experimental and computational approach. Preferentially, we analyzed the characteristics of seizure-like events (SLEs) using our previous in vitro experimental data. The results were analyzed in two groups classified according to the size of the effective region, in which the SLE was able to be completely suppressed by local stimulation. However, no significant differences were found between these two groups in terms of signal features or propagation characteristics (i.e., propagation delays, frequency spectrum, and phase synchrony). Thus, we further investigated important factors using a computational model that was capable of evaluating specific influences on effective region size. In the proposed model, signal transmission between neurons was based on two different mechanisms: synaptic transmission and the electrical field effect. We were able to induce SLEs having similar characteristics with differentially weighted adjustments for the two transmission methods in various noise environments. Although the SLEs had similar characteristics, their suppression effects differed. First of all, the suppression effect occurred only locally where directly received the stimulation effect in the high noise environment, but it occurred in the entire network in the low noise environment. Interestingly, in the same noise environment, the suppression effect was different depending on SLE propagation mechanism; only a local suppression effect was observed when the influence of the electrical field transmission was very weak, whereas a global effect was observed with a stronger electrical field effect. These results indicate that neuronal activities synchronized by a strong electrical field effect respond more sensitively to partial changes in the entire network. In addition, the proposed model was able to predict that stimulation of a seizure focus region is more effective for suppression. In conclusion, we confirmed the possibility of a computational model as a simulation tool to analyze the efficacy of deep brain stimulation (DBS) and investigated the key factors that determine the size of an effective region in seizure suppression via electrical stimulation.
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Affiliation(s)
- Sora Ahn
- Department of Electronic and Electrical Engineering, Ewha Womans UniversitySeoul, South Korea
| | - Sumin Jo
- Department of Electronic and Electrical Engineering, Ewha Womans UniversitySeoul, South Korea
| | - Sang Beom Jun
- Department of Electronic and Electrical Engineering, Ewha Womans UniversitySeoul, South Korea
| | - Hyang Woon Lee
- Department of Neurology, Ewha Womans University School of Medicine and Ewha Medical Research InstituteSeoul, South Korea
| | - Seungjun Lee
- Department of Electronic and Electrical Engineering, Ewha Womans UniversitySeoul, South Korea
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