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Wendling F, Koksal-Ersoz E, Al-Harrach M, Yochum M, Merlet I, Ruffini G, Bartolomei F, Benquet P. Multiscale neuro-inspired models for interpretation of EEG signals in patients with epilepsy. Clin Neurophysiol 2024; 161:198-210. [PMID: 38520800 DOI: 10.1016/j.clinph.2024.03.006] [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: 09/15/2023] [Revised: 03/06/2024] [Accepted: 03/11/2024] [Indexed: 03/25/2024]
Abstract
OBJECTIVE The aim is to gain insight into the pathophysiological mechanisms underlying interictal epileptiform discharges observed in electroencephalographic (EEG) and stereo-EEG (SEEG, depth electrodes) recordings performed during pre-surgical evaluation of patients with drug-resistant epilepsy. METHODS We developed novel neuro-inspired computational models of the human cerebral cortex at three different levels of description: i) microscale (detailed neuron models), ii) mesoscale (neuronal mass models) and iii) macroscale (whole brain models). Although conceptually different, micro- and mesoscale models share some similar features, such as the typology of neurons (pyramidal cells and three types of interneurons), their spatial arrangement in cortical layers, and their synaptic connectivity (excitatory and inhibitory). The whole brain model consists of a large-scale network of interconnected neuronal masses, with connectivity based on the human connectome. RESULTS For these three levels of description, the fine-tuning of free parameters and the quantitative comparison with real data allowed us to reproduce interictal epileptiform discharges with a high degree of fidelity and to formulate hypotheses about the cell- and network-related mechanisms underlying the generation of fast ripples and SEEG-recorded epileptic spikes and spike-waves. CONCLUSIONS The proposed models provide valuable insights into the pathophysiological mechanisms underlying the generation of epileptic events. The knowledge gained from these models effectively complements the clinical analysis of SEEG data collected during the evaluation of patients with epilepsy. SIGNIFICANCE These models are likely to play a key role in the mechanistic interpretation of epileptiform activity.
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Affiliation(s)
| | | | | | | | | | | | - Fabrice Bartolomei
- APHM, Timone Hospital, Epileptology and Cerebral Rhythmology Department, Marseille, France; Univ Aix Marseille, INSERM, INS, Inst Neurosci Syst, Marseille, France
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2
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Adeyelu T, Ogundele OM. VTA multifaceted modulation of CA1 local circuits. Neurobiol Learn Mem 2023; 202:107760. [PMID: 37119849 DOI: 10.1016/j.nlm.2023.107760] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 04/18/2023] [Accepted: 04/22/2023] [Indexed: 05/01/2023]
Abstract
Excitatory pyramidal (PYR) cell activation of interneurons (INT) produces network oscillations that underlie cognitive processes in the CA1. Neural projections from the ventral tegmental area (VTA) to the hippocampus contribute to novelty detection by modulating CA1 PYR and INT activity. The role of the VTA in the VTA-hippocampus loop is mostly attributed to the dopamine neurons although the VTA glutamate-releasing terminals are dominant in the hippocampus. Because of the traditional focus on VTA dopamine circuits, how VTA glutamate inputs modulate PYR activation of INT in CA1 neuronal ensembles is poorly understood and has not been distinguished from the VTA dopamine inputs. By combining CA1 extracellular recording with VTA photostimulation in anesthetized mice, we compared the effects of VTA dopamine and glutamate input on CA1 PYR/INT connections. Stimulation of VTA glutamate neurons shortened PYR/INT connection time without altering the synchronization or connectivity strength. Conversely, activation of VTA dopamine inputs delayed CA1 PYR/INT connection time and increased the synchronization in putative pairs. Taken together, we conclude that VTA dopamine and glutamate projections produce tract-specific effects on CA1 PYR/INT connectivity and synchrony. As such, selective activation or co-activation of these systems will likely produce a range of modulatory effects on local CA1 circuits.
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Affiliation(s)
- Tolulope Adeyelu
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine. Baton Rouge, LA70803, Louisiana
| | - Olalekan M Ogundele
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine. Baton Rouge, LA70803, Louisiana.
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3
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Aussel A, Ranta R, Aron O, Colnat-Coulbois S, Maillard L, Buhry L. Cell to network computational model of the epileptic human hippocampus suggests specific roles of network and channel dysfunctions in the ictal and interictal oscillations. J Comput Neurosci 2022; 50:519-535. [PMID: 35971033 DOI: 10.1007/s10827-022-00829-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 07/03/2022] [Accepted: 07/12/2022] [Indexed: 10/15/2022]
Abstract
The mechanisms underlying the generation of hippocampal epileptic seizures and interictal events and their interactions with the sleep-wake cycle are not yet fully understood. Indeed, medial temporal lobe epilepsy is associated with hippocampal abnormalities both at the neuronal (channelopathies, impaired potassium and chloride dynamics) and network level (neuronal and axonal loss, mossy fiber sprouting), with more frequent seizures during wakefulness compared with slow-wave sleep. In this article, starting from our previous computational modeling work of the hippocampal formation based on realistic topology and synaptic connectivity, we study the role of micro- and mesoscale pathological conditions of the epileptic hippocampus in the generation and maintenance of seizure-like theta and interictal oscillations. We show, through the simulations of hippocampal activity during slow-wave sleep and wakefulness that: (i) both mossy fiber sprouting and sclerosis account for seizure-like theta activity, (ii) but they have antagonist effects (seizure-like activity occurrence increases with sprouting but decreases with sclerosis), (iii) though impaired potassium and chloride dynamics have little influence on the generation of seizure-like activity, they do play a role on the generation of interictal patterns, and (iv) seizure-like activity and fast ripples are more likely to occur during wakefulness and interictal spikes during sleep.
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Affiliation(s)
- Amélie Aussel
- Laboratoire Lorrain de Recherche en Informatique et ses applications (LORIA UMR 7503), University of Lorraine, 54506, Nancy, France. .,Centre de Recherche en Automatique de Nancy, University of Lorraine, CRAN-CNRS UMR 7039, Nancy, France.
| | - Radu Ranta
- Centre de Recherche en Automatique de Nancy, University of Lorraine, CRAN-CNRS UMR 7039, Nancy, France
| | - Olivier Aron
- Centre de Recherche en Automatique de Nancy, University of Lorraine, CRAN-CNRS UMR 7039, Nancy, France.,Department of Neurology, CHU de Nancy, Nancy, France
| | - Sophie Colnat-Coulbois
- Centre de Recherche en Automatique de Nancy, University of Lorraine, CRAN-CNRS UMR 7039, Nancy, France.,Department of Neurology, CHU de Nancy, Nancy, France
| | - Louise Maillard
- Centre de Recherche en Automatique de Nancy, University of Lorraine, CRAN-CNRS UMR 7039, Nancy, France.,Department of Neurology, CHU de Nancy, Nancy, France
| | - Laure Buhry
- Laboratoire Lorrain de Recherche en Informatique et ses applications (LORIA UMR 7503), University of Lorraine, 54506, Nancy, France
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Shrestha A, Sultana R, Lee CC, Ogundele OM. SK Channel Modulates Synaptic Plasticity by Tuning CaMKIIα/β Dynamics. Front Synaptic Neurosci 2019; 11:18. [PMID: 31736736 PMCID: PMC6834780 DOI: 10.3389/fnsyn.2019.00018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 05/20/2019] [Indexed: 11/13/2022] Open
Abstract
N-Methyl-D-Aspartate Receptor 1 (NMDAR)-linked Ca++ current represents a significant percentage of post-synaptic transient that modulates synaptic strength and is pertinent to dendritic spine plasticity. In the hippocampus, Ca++ transient produced by glutamatergic ionotropic neurotransmission facilitates Ca++-Calmodulin-dependent kinase 2 (CaMKII) Thr286 phosphorylation and promote long-term potentiation (LTP) expression. At CA1 post-synaptic densities, Ca++ transients equally activate small conductance (SK2) channel which regulates excitability by suppressing Ca++ movement. Here, we demonstrate that upstream attenuation of GluN1 function in the hippocampus led to a decrease in Thr286 CaMKIIα phosphorylation, and increased SK2 expression. Consistent with the loss of GluN1 function, potentiation of SK channel in wild type hippocampus reduced CaMKIIα expression and abrogate synaptic localization of T286 pCaMKIIα. Our results demonstrate that positive modulation of SK channel at hippocampal synapses likely refine GluN1-linked plasticity by tuning dendritic localization of CaMKIIα.
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Affiliation(s)
| | | | | | - Olalekan M. Ogundele
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA, United States
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5
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Buchin A, Kerr CC, Huberfeld G, Miles R, Gutkin B. Adaptation and Inhibition Control Pathological Synchronization in a Model of Focal Epileptic Seizure. eNeuro 2018; 5:ENEURO.0019-18.2018. [PMID: 30302390 PMCID: PMC6173584 DOI: 10.1523/eneuro.0019-18.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 06/07/2018] [Accepted: 06/07/2018] [Indexed: 01/12/2023] Open
Abstract
Pharmacoresistant epilepsy is a common neurological disorder in which increased neuronal intrinsic excitability and synaptic excitation lead to pathologically synchronous behavior in the brain. In the majority of experimental and theoretical epilepsy models, epilepsy is associated with reduced inhibition in the pathological neural circuits, yet effects of intrinsic excitability are usually not explicitly analyzed. Here we present a novel neural mass model that includes intrinsic excitability in the form of spike-frequency adaptation in the excitatory population. We validated our model using local field potential (LFP) data recorded from human hippocampal/subicular slices. We found that synaptic conductances and slow adaptation in the excitatory population both play essential roles for generating seizures and pre-ictal oscillations. Using bifurcation analysis, we found that transitions towards seizure and back to the resting state take place via Andronov-Hopf bifurcations. These simulations therefore suggest that single neuron adaptation as well as synaptic inhibition are responsible for orchestrating seizure dynamics and transition towards the epileptic state.
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Affiliation(s)
- Anatoly Buchin
- University of Washington, Department of Physiology and Biophysics (United States, Seattle), 1959 NE Pacific St, 98195
| | - Cliff C. Kerr
- University of Sydney, School of Physics (Australia, Sydney), Physics Rd, NSW 2006
| | - Gilles Huberfeld
- Sorbonne Université-UPMC, Pitié-Salpêtrière Hô, Neurophysiology Department (France, Paris), 47-83 Boulevard de l’Hôpital, 75013
- Institut national de la santé et de la recherche médicale Unit 1129 “Infantile Epilepsies and Brain Plasticity”, Paris Descartes University, Sorbonne Paris Cité University group, (France, Paris), 149 rue de Sévres 75015
| | - Richard Miles
- Brain and Spine Institute, Cortex and Epilepsie Group (France, Paris), 47 Boulevard Hôpital, 75013
| | - Boris Gutkin
- Paris Sciences & Lettres Research University, Laboratoire des Neurosciences Cognitives, Group for Neural Theory (France, Paris), 29, rue d'Ulm, 75005 France
- National Research University Higher School of Economics, Center for Cognition and Decision Making (Russia, Moscow), 20 Myasnitskaya, 109316
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Zhang L, Fan D, Wang Q. Synchronous high-frequency oscillations in inhibitory-dominant network motifs consisting of three dentate gyrus-CA3 systems. CHAOS (WOODBURY, N.Y.) 2018; 28:063101. [PMID: 29960405 DOI: 10.1063/1.5017012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Studies on the structural-functional connectomes of the human brain have demonstrated the existence of synchronous firings in a specific brain network motif. In particular, synchronization of high-frequency oscillations (HFOs) has been observed in the experimental data sets of temporal lobe epilepsy (TLE). In addition, both clinical and experimental evidences have accumulated to demonstrate the effect of electrical stimulation on TLE, which, however, remains largely unexplored. In this work, we first employ our previously proposed dentate gyrus (DG)-CA3 network model to investigate the influence of an external electrical stimulus on the HFO transitions. The results indicate that the reinforcing stimulus can induce the HFO transitions of the DG-CA3 system from the gamma band to the fast ripples band. Along with that, the consistent oscillations of neurons within DG-CA3 can also be enhanced with the increasing of stimulus. Then, we expand into a simple motif of three coupled DG-CA3 systems in both the feedforward inhibition and feedback inhibition connections, to investigate the synchronous evolutions of HFOs by regulating both the stimulation strength and inhibitory function. It is shown that the comprehensive effects, which lead to band transition, are independent of the motif configurations. The enhanced external electrical stimulus weakens the synchronism and correlation of connected motifs. In contrast, we demonstrate that the increased inhibitory coupling could facilitate correlation to some extent. Overall, our work highlights the possible origin of synchronous HFOs of hippocampal motifs governed by external inputs and inhibitory connection, which might contribute to a better understanding of the interplay between synchronization dynamics and epileptic structure in the human brain.
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Affiliation(s)
- Liyuan Zhang
- Department of Dynamics and Control, Beihang University, Beijing 100191, China
| | - Denggui Fan
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Qingyun Wang
- Department of Dynamics and Control, Beihang University, Beijing 100191, China
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Chizhov AV, Amakhin DV, Zaizev AV, Magazanik LG. AMPAR-mediated Interictal Discharges in Neurons of Entorhinal Cortex: Experiment and Model. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2018; 479:47-50. [PMID: 29790025 DOI: 10.1134/s0012496618020011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Indexed: 06/08/2023]
Abstract
The mechanisms of interictal discharges (IID) were studied under the conditions of the 4-aminopyridine model of spontaneous epileptiform activity in surviving rat brain slice preparations. Addition of the agents blocking GABA and NMDA receptors failed to inhibit IID generation in the entorhinal cortex. A mathematical model of IID has been developed on the basis of the excitatory neuron interaction mediated by the AMPA receptor. Short-term synaptic depression and slow afterspike-hyperpolarization are the key factors required to terminate a single IID. The IID shape-determining factors have been identified. The experimental and model IID features correspond to each other.
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Affiliation(s)
- A V Chizhov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.
- Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg, Russia.
| | - D V Amakhin
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - A V Zaizev
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - L G Magazanik
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
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Sultana R, Ghandi T, M. Davila A, Lee CC, Ogundele OM. Upregulated SK2 Expression and Impaired CaMKII Phosphorylation Are Shared Synaptic Defects Between 16p11.2del and 129S: Δdisc1 Mutant Mice. ASN Neuro 2018; 10:1759091418817641. [PMID: 33592687 PMCID: PMC6295693 DOI: 10.1177/1759091418817641] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 11/07/2018] [Accepted: 11/09/2018] [Indexed: 12/29/2022] Open
Abstract
Ion channel gating and kinase regulation of N-methyl-D-aspartate receptor 1 activity are fundamental mechanisms that govern synaptic plasticity. In this study, we showed that two mutant models (16p11.2del and Δdisc1 ) that recapitulate aspects of human cognitive disorders shared a similar defect in N-methyl-D-aspartate receptor 1-dependent synaptic function. Our results demonstrate that the expression of small-conductance potassium channels (SK2 or KCa2.2) was significantly upregulated in the hippocampus and prefrontal cortex of 16p11.2del and 129S:Δdisc1 mutant mice. Likewise, both mutant strains exhibited an impairment of T286 phosphorylation of calcium-calmodulin-dependent kinase II (CaMKII) in the hippocampus and prefrontal cortex. In vivo neural recordings revealed that increased SK2 expression and impaired T286 phosphorylation of CaMKII coincide with a prolonged interspike interval in the hippocampal cornu ammonis-1 (CA1) field for both 16p11.2del and 129S:Δdisc1 mutant mice. These findings suggest that alteration of small conductance channels and T286 phosphorylation of CaMKII are likely shared factors underlying behavioral changes in these two genetic mouse models.
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Affiliation(s)
- Razia Sultana
- Department of Comparative Biomedical Sciences, Louisiana State
University School of Veterinary Medicine, Baton Rouge, LA, USA
| | - Tanya Ghandi
- Department of Comparative Biomedical Sciences, Louisiana State
University School of Veterinary Medicine, Baton Rouge, LA, USA
| | - Alexandra M. Davila
- Department of Comparative Biomedical Sciences, Louisiana State
University School of Veterinary Medicine, Baton Rouge, LA, USA
| | - Charles C. Lee
- Department of Comparative Biomedical Sciences, Louisiana State
University School of Veterinary Medicine, Baton Rouge, LA, USA
| | - Olalekan M. Ogundele
- Department of Comparative Biomedical Sciences, Louisiana State
University School of Veterinary Medicine, Baton Rouge, LA, USA
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Computational model of interictal discharges triggered by interneurons. PLoS One 2017; 12:e0185752. [PMID: 28977038 PMCID: PMC5627938 DOI: 10.1371/journal.pone.0185752] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 09/19/2017] [Indexed: 11/19/2022] Open
Abstract
Interictal discharges (IIDs) are abnormal waveforms registered in the periods before or between seizures. IIDs that are initiated by GABAergic interneurons have not been mathematically modeled yet. In the present study, a mathematical model that describes the mechanisms of these discharges is proposed. The model is based on the experimental recordings of IIDs in pyramidal neurons of the rat entorhinal cortex and estimations of synaptic conductances during IIDs. IIDs were induced in cortico-hippocampal slices by applying an extracellular solution with 4-aminopyridine, high potassium, and low magnesium concentrations. Two different types of IIDs initiated by interneurons were observed. The first type of IID (IID1) was pure GABAergic. The second type of IID (IID2) was induced by GABAergic excitation and maintained by recurrent interactions of both GABA- and glutamatergic neuronal populations. The model employed the conductance-based refractory density (CBRD) approach, which accurately approximates the firing rate of a population of similar Hodgkin-Huxley-like neurons. The model of coupled excitatory and inhibitory populations includes AMPA, NMDA, and GABA-receptor-mediated synapses and gap junctions. These neurons receive both arbitrary deterministic input and individual colored Gaussian noise. Both types of IIDs were successfully reproduced in the model by setting two different depolarized levels for GABA-mediated current reversal potential. It was revealed that short-term synaptic depression is a crucial factor in ceasing each of the discharges, and it also determines their durations and frequencies.
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10
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Zhang L, Fan D, Wang Q. Transition Dynamics of a Dentate Gyrus-CA3 Neuronal Network during Temporal Lobe Epilepsy. Front Comput Neurosci 2017; 11:61. [PMID: 28744210 PMCID: PMC5504536 DOI: 10.3389/fncom.2017.00061] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 06/26/2017] [Indexed: 01/21/2023] Open
Abstract
In temporal lobe epilepsy (TLE), the variation of chemical receptor expression underlies the basis of neural network activity shifts, resulting in neuronal hyperexcitability and epileptiform discharges. However, dynamical mechanisms involved in the transitions of TLE are not fully understood, because of the neuronal diversity and the indeterminacy of network connection. Hence, based on Hodgkin–Huxley (HH) type neurons and Pinsky–Rinzel (PR) type neurons coupling with glutamatergic and GABAergic synaptic connections respectively, we propose a computational framework which contains dentate gyrus (DG) region and CA3 region. By regulating the concentration range of N-methyl-D-aspartate-type glutamate receptor (NMDAR), we demonstrate the pyramidal neuron can generate transitions from interictal to seizure discharges. This suggests that enhanced endogenous activity of NMDAR contributes to excitability in pyramidal neuron. Moreover, we conclude that excitatory discharges in CA3 region vary considerably on account of the excitatory currents produced by the excitatory pyramidal neuron. Interestingly, by changing the backprojection connection, we find that glutamatergic type backprojection can promote the dominant frequency of firings and further motivate excitatory counterpropagation from CA3 region to DG region. However, GABAergic type backprojection can reduce firing rate and block morbid counterpropagation, which may be factored into the terminations of TLE. In addition, neuronal diversity dominated network shows weak correlation with different backprojections. Our modeling and simulation studies provide new insights into the mechanisms of seizures generation and connectionism in local hippocampus, along with the synaptic mechanisms of this disease.
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Affiliation(s)
- Liyuan Zhang
- Department of Dynamics and Control, Beihang UniversityBeijing, China
| | - Denggui Fan
- Department of Information and Computing Science, School of Mathematics and Physics, University of Science and Technology BeijingBeijing, China
| | - Qingyun Wang
- Department of Dynamics and Control, Beihang UniversityBeijing, China
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Computational models of epileptiform activity. J Neurosci Methods 2016; 260:233-51. [DOI: 10.1016/j.jneumeth.2015.03.027] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 12/24/2022]
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Rao AR, Cecchi GA, Kaplan E. Editorial: Towards an integrated approach to measurement, analysis and modeling of cortical networks. Front Neural Circuits 2015; 9:61. [PMID: 26539082 PMCID: PMC4611055 DOI: 10.3389/fncir.2015.00061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/28/2015] [Indexed: 11/13/2022] Open
Affiliation(s)
- A Ravishankar Rao
- Gildart Haase School of Computer Sciences and Engineering, Fairleigh Dickinson University Teaneck, NJ, USA
| | | | - Ehud Kaplan
- Icahn School of Medicine at Mount Sinai New York, NY, USA
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Vega-Zelaya L, Pastor J, Tormo I, de Sola RG, Ortega GJ. Assessing the equivalence between etomidate and seizure network dynamics in temporal lobe epilepsy. Clin Neurophysiol 2015; 127:169-178. [PMID: 26070516 DOI: 10.1016/j.clinph.2015.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 04/09/2015] [Accepted: 05/06/2015] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Etomidate mimics some typical epileptic neurophysiological features, such as the appearance of spikes and high frequency oscillations, when it is administrated to epileptic patients. However, little is known about its influence on the underlying cortical network. An assessment of comparable cortical dynamics between seizures and etomidate would allow for a more detailed study of the network parameters underlying the ictal stage by using etomidate as a proxy. The objective of the present work is to show that temporal lobe seizures produce network changes comparable to the ones elicited by etomidate administration. METHODS Scalp and foramen ovale electrodes (FOE) recordings from nine temporal lobe epilepsy patients were analyzed under the complex network perspective. The clustering coefficients, average path lengths, density of links, modularity and spectral entropy were calculated during the pre-ictal and ictal stages and post-etomidate administration. Etomidate administration produced no seizure in any of the analyzed cases. RESULTS The density of lines (six of nine patients) and spectral entropy (eight of nine patients) displayed similar behavior to the preictal-ictal transition when etomidate effects altered the epileptic network (FOE+scalp). When considering only the mesial sub-network, changes induced by etomidate perfusion replicated the same type of imbalance observed during the ictal stage in the nine patient's sample and in eight out of nine regarding the preictal stage. Both statistical significance at a level of 1% and size effects, evaluated by using the standardized mean differences, show similar network changes during the preictal-ictal and preictal-etomidate transitions. CONCLUSIONS Etomidate perfusion in patients with temporal lobe epilepsy induces network changes comparable to the changes resulting from seizures. SIGNIFICANCE The finding reported here could improve the study of network dynamics during the ictal phase, not only with electrophysiological methods, but also in other cases, such as functional magnetic resonance imaging.
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Affiliation(s)
- Lorena Vega-Zelaya
- Clinical Neurophysiology, Hospital Universitario de la Princesa, Madrid, Spain; Instituto de Investigación Sanitaria Hospital Universitario de la Princesa, Madrid, Spain
| | - Jesús Pastor
- Clinical Neurophysiology, Hospital Universitario de la Princesa, Madrid, Spain; Instituto de Investigación Sanitaria Hospital Universitario de la Princesa, Madrid, Spain
| | - Isabel Tormo
- Clinical Neurophysiology, Hospital Universitario de la Princesa, Madrid, Spain
| | - Rafael G de Sola
- Neurosurgery, Hospital Universitario de la Princesa, Madrid, Spain; Instituto de Investigación Sanitaria Hospital Universitario de la Princesa, Madrid, Spain
| | - Guillermo J Ortega
- Neurosurgery, Hospital Universitario de la Princesa, Madrid, Spain; Instituto de Investigación Sanitaria Hospital Universitario de la Princesa, Madrid, Spain.
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