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Mercier O, Quilichini PP, Magalon K, Gil F, Ghestem A, Richard F, Boudier T, Cayre M, Durbec P. Transient demyelination causes long-term cognitive impairment, myelin alteration and network synchrony defects. Glia 2024; 72:960-981. [PMID: 38363046 DOI: 10.1002/glia.24513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 01/26/2024] [Accepted: 02/05/2024] [Indexed: 02/17/2024]
Abstract
In the adult brain, activity-dependent myelin plasticity is required for proper learning and memory consolidation. Myelin loss, alteration, or even subtle structural modifications can therefore compromise the network activity, leading to functional impairment. In multiple sclerosis, spontaneous myelin repair process is possible, but it is heterogeneous among patients, sometimes leading to functional recovery, often more visible at the motor level than at the cognitive level. In cuprizone-treated mouse model, massive brain demyelination is followed by spontaneous and robust remyelination. However, reformed myelin, although functional, may not exhibit the same morphological characteristics as developmental myelin, which can have an impact on the activity of neural networks. In this context, we used the cuprizone-treated mouse model to analyze the structural, functional, and cognitive long-term effects of transient demyelination. Our results show that an episode of demyelination induces despite remyelination long-term cognitive impairment, such as deficits in spatial working memory, social memory, cognitive flexibility, and hyperactivity. These deficits were associated with a reduction in myelin content in the medial prefrontal cortex (mPFC) and hippocampus (HPC), as well as structural myelin modifications, suggesting that the remyelination process may be imperfect in these structures. In vivo electrophysiological recordings showed that the demyelination episode altered the synchronization of HPC-mPFC activity, which is crucial for memory processes. Altogether, our data indicate that the myelin repair process following transient demyelination does not allow the complete recovery of the initial myelin properties in cortical structures. These subtle modifications alter network features, leading to prolonged cognitive deficits in mice.
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Affiliation(s)
- Océane Mercier
- UMR7288 after IBDM, Aix Marseille Univ, CNRS, IBDM, Marseille, France
| | - Pascale P Quilichini
- U1106 after INS, Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - Karine Magalon
- UMR7288 after IBDM, Aix Marseille Univ, CNRS, IBDM, Marseille, France
| | - Florian Gil
- UMR7288 after IBDM, Aix Marseille Univ, CNRS, IBDM, Marseille, France
| | - Antoine Ghestem
- U1106 after INS, Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - Fabrice Richard
- UMR7288 after IBDM, Aix Marseille Univ, CNRS, IBDM, Marseille, France
| | - Thomas Boudier
- Aix Marseille Univ, Turing Centre for Living Systems, Marseille, France
| | - Myriam Cayre
- UMR7288 after IBDM, Aix Marseille Univ, CNRS, IBDM, Marseille, France
| | - Pascale Durbec
- UMR7288 after IBDM, Aix Marseille Univ, CNRS, IBDM, Marseille, France
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2
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Clawson W, Waked B, Madec T, Ghestem A, Quilichini PP, Battaglia D, Bernard C. Perturbed Information Processing Complexity in Experimental Epilepsy. J Neurosci 2023; 43:6573-6587. [PMID: 37550052 PMCID: PMC10513075 DOI: 10.1523/jneurosci.0383-23.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 07/07/2023] [Accepted: 07/20/2023] [Indexed: 08/09/2023] Open
Abstract
Comorbidities, such as cognitive deficits, which often accompany epilepsies, constitute a basal state, while seizures are rare and transient events. This suggests that neural dynamics, in particular those supporting cognitive function, are altered in a permanent manner in epilepsy. Here, we test the hypothesis that primitive processes of information processing at the core of cognitive function (i.e., storage and sharing of information) are altered in the hippocampus and the entorhinal cortex in experimental epilepsy in adult, male Wistar rats. We find that information storage and sharing are organized into substates across the stereotypic states of slow and theta oscillations in both epilepsy and control conditions. However, their internal composition and organization through time are disrupted in epilepsy, partially losing brain state selectivity compared with controls, and shifting toward a regimen of disorder. We propose that the alteration of information processing at this algorithmic level of computation, the theoretical intermediate level between structure and function, may be a mechanism behind the emergent and widespread comorbidities associated with epilepsy, and perhaps other disorders.SIGNIFICANCE STATEMENT Comorbidities, such as cognitive deficits, which often accompany epilepsies, constitute a basal state, while seizures are rare and transient events. This suggests that neural dynamics, in particular those supporting cognitive function, are altered in a permanent manner in epilepsy. Here, we show that basic processes of information processing at the core of cognitive function (i.e., storage and sharing of information) are altered in the hippocampus and the entorhinal cortex (two regions involved in memory processes) in experimental epilepsy. Such disruption of information processing at the algorithmic level itself could underlie the general performance impairments in epilepsy.
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Affiliation(s)
- Wesley Clawson
- Aix Marseille Université, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, France
- Allen Discovery Center, Tufts University, Medford, Massachusetts
| | - Benjamin Waked
- Aix Marseille Université, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, France
| | - Tanguy Madec
- Aix Marseille Université, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, France
| | - Antoine Ghestem
- Aix Marseille Université, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, France
| | - Pascale P Quilichini
- Aix Marseille Université, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, France
| | - Demian Battaglia
- Aix Marseille Université, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, France
- University of Strasbourg Institute for Advanced Studies, Strasbourg, France
| | - Christophe Bernard
- Aix Marseille Université, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, France
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3
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Lamtahri R, Hazime M, Gowing EK, Nagaraja RY, Maucotel J, Alasoadura M, Quilichini PP, Lehongre K, Lefranc B, Gach-Janczak K, Marcher AB, Mandrup S, Vaudry D, Clarkson AN, Leprince J, Chuquet J. The Gliopeptide ODN, a Ligand for the Benzodiazepine Site of GABA A Receptors, Boosts Functional Recovery after Stroke. J Neurosci 2021; 41:7148-7159. [PMID: 34210784 PMCID: PMC8372017 DOI: 10.1523/jneurosci.2255-20.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 12/14/2020] [Accepted: 03/25/2021] [Indexed: 11/21/2022] Open
Abstract
Following stroke, the survival of neurons and their ability to reestablish connections is critical to functional recovery. This is strongly influenced by the balance between neuronal excitation and inhibition. In the acute phase of experimental stroke, lethal hyperexcitability can be attenuated by positive allosteric modulation of GABAA receptors (GABAARs). Conversely, in the late phase, negative allosteric modulation of GABAAR can correct the suboptimal excitability and improves both sensory and motor recovery. Here, we hypothesized that octadecaneuropeptide (ODN), an endogenous allosteric modulator of the GABAAR synthesized by astrocytes, influences the outcome of ischemic brain tissue and subsequent functional recovery. We show that ODN boosts the excitability of cortical neurons, which makes it deleterious in the acute phase of stroke. However, if delivered after day 3, ODN is safe and improves motor recovery over the following month in two different paradigms of experimental stroke in mice. Furthermore, we bring evidence that, during the subacute period after stroke, the repairing cortex can be treated with ODN by means of a single hydrogel deposit into the stroke cavity.SIGNIFICANCE STATEMENT Stroke remains a devastating clinical challenge because there is no efficient therapy to either minimize neuronal death with neuroprotective drugs or to enhance spontaneous recovery with neurorepair drugs. Around the brain damage, the peri-infarct cortex can be viewed as a reservoir of plasticity. However, the potential of wiring new circuits in these areas is restrained by a chronic excess of GABAergic inhibition. Here we show that an astrocyte-derived peptide, can be used as a delayed treatment, to safely correct cortical excitability and facilitate sensorimotor recovery after stroke.
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Affiliation(s)
- Rhita Lamtahri
- Normandie Université, UNIROUEN, Institut National de la Santé et de la Recherche Médicale U1239, Neuronal and Neuroendocrine Differentiation and Communication, Rouen, France
| | - Mahmoud Hazime
- Normandie Université, UNIROUEN, Institut National de la Santé et de la Recherche Médicale U1239, Neuronal and Neuroendocrine Differentiation and Communication, Rouen, France
| | - Emma K Gowing
- Department of Anatomy, Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, 76000, 9054, New Zealand
| | - Raghavendra Y Nagaraja
- Department of Anatomy, Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, 76000, 9054, New Zealand
| | - Julie Maucotel
- Normandie Université, UNIROUEN, Animal Facility, Rouen, 76000, France
| | - Michael Alasoadura
- Normandie Université, UNIROUEN, Institut National de la Santé et de la Recherche Médicale U1239, Neuronal and Neuroendocrine Differentiation and Communication, Rouen, France
| | | | - Katia Lehongre
- Inserm U 1127, Centre National de la Recherche Scientifique Unite Mixte de Recherche 7225, Sorbonne Universités, UPMC Univ Paris 06 Unite Mixte de Recherche S 1127, Institut du Cerveau et de la Moelle épinière, ICM, Paris, F-75013, France
| | - Benjamin Lefranc
- Normandie Université, UNIROUEN, Institut National de la Santé et de la Recherche Médicale U1239, Neuronal and Neuroendocrine Differentiation and Communication, Rouen, France
- Institute for Research and Innovation in Biomedicine, Normandie Université, PRIMACEN, Rouen, 76000, France
| | - Katarzyna Gach-Janczak
- Normandie Université, UNIROUEN, Institut National de la Santé et de la Recherche Médicale U1239, Neuronal and Neuroendocrine Differentiation and Communication, Rouen, France
- Department of Biomolecular Chemistry, Medicinal University of Łódź, Łódź, 90-137, Poland
| | - Ann-Britt Marcher
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, 5230, Denmark
| | - Susanne Mandrup
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, 5230, Denmark
| | - David Vaudry
- Normandie Université, UNIROUEN, Institut National de la Santé et de la Recherche Médicale U1239, Neuronal and Neuroendocrine Differentiation and Communication, Rouen, France
- Institute for Research and Innovation in Biomedicine, Normandie Université, PRIMACEN, Rouen, 76000, France
| | - Andrew N Clarkson
- Department of Anatomy, Brain Health Research Centre and Brain Research New Zealand, University of Otago, Dunedin, 76000, 9054, New Zealand
| | - Jérôme Leprince
- Normandie Université, UNIROUEN, Institut National de la Santé et de la Recherche Médicale U1239, Neuronal and Neuroendocrine Differentiation and Communication, Rouen, France
- Institute for Research and Innovation in Biomedicine, Normandie Université, PRIMACEN, Rouen, 76000, France
| | - Julien Chuquet
- Normandie Université, UNIROUEN, Institut National de la Santé et de la Recherche Médicale U1239, Neuronal and Neuroendocrine Differentiation and Communication, Rouen, France
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Ferraris M, Cassel JC, Pereira de Vasconcelos A, Stephan A, Quilichini PP. The nucleus reuniens, a thalamic relay for cortico-hippocampal interaction in recent and remote memory consolidation. Neurosci Biobehav Rev 2021; 125:339-354. [PMID: 33631314 DOI: 10.1016/j.neubiorev.2021.02.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 02/15/2021] [Accepted: 02/16/2021] [Indexed: 12/12/2022]
Abstract
The consolidation of declarative memories is believed to occur mostly during sleep and involves a dialogue between two brain regions, the hippocampus and the medial prefrontal cortex. The information encoded during experience by neuronal assemblies is replayed during sleep leading to the progressive strengthening and integration of the memory trace in the prefrontal cortex. The gradual transfer of information from the hippocampus to the medial prefrontal cortex for long-term storage requires the synchronization of cortico-hippocampal networks by different oscillations, like ripples, spindles, and slow oscillations. Recent studies suggest the involvement of a third partner, the nucleus reuniens, in memory consolidation. Its bidirectional connections with the hippocampus and medial prefrontal cortex place the reuniens in a key position to relay information between the two structures. Indeed, many topical works reveal the original role that the nucleus reuniens occupies in different recent and remote memories consolidation. This review aimed to examine these contributions, as well as its functional embedment in this complex memory network, and provide some insights on the possible mechanisms.
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Affiliation(s)
- Maëva Ferraris
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - Jean-Christophe Cassel
- Laboratoire De Neurosciences Cognitives Et Adaptatives, Université De Strasbourg, F-67000, Strasbourg, France; LNCA, UMR 7364 - CNRS, F-67000, Strasbourg, France
| | - Anne Pereira de Vasconcelos
- Laboratoire De Neurosciences Cognitives Et Adaptatives, Université De Strasbourg, F-67000, Strasbourg, France; LNCA, UMR 7364 - CNRS, F-67000, Strasbourg, France
| | - Aline Stephan
- Laboratoire De Neurosciences Cognitives Et Adaptatives, Université De Strasbourg, F-67000, Strasbourg, France; LNCA, UMR 7364 - CNRS, F-67000, Strasbourg, France
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5
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Vicente AF, Slézia A, Ghestem A, Bernard C, Quilichini PP. In Vivo Characterization of Neurophysiological Diversity in the Lateral Supramammillary Nucleus during Hippocampal Sharp-wave Ripples of Adult Rats. Neuroscience 2020; 435:95-111. [PMID: 32222556 DOI: 10.1016/j.neuroscience.2020.03.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 02/13/2020] [Accepted: 03/22/2020] [Indexed: 01/12/2023]
Abstract
The extent of the networks that control the genesis and modulation of hippocampal sharp-wave ripples (SPW-Rs), which are involved in memory consolidation, remains incompletely understood. Here, we performed a detailed in vivo analysis of single cell firing in the lateral supramammillary nucleus (lSuM) during theta and slow oscillations, including SPW-Rs, in anesthetized rats. We classified neurons as SPW-R-active and SPW-R-unchanged according to whether or not they increased their firing during SPW-Rs. We show that lSuM SPW-R-active neurons increase their firing prior to SPW-Rs peak power and prior to hippocampal excitatory cell activation. Moreover, lSuM SPW-R-active neurons show increased firing activity during theta and slow oscillations as compared to unchanged neurons. These results suggest that a sub-population of lSuM neurons can interact with the hippocampus during SPW-Rs, raising the possibility that the lSuM may modulate memory consolidation.
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Affiliation(s)
- Ana F Vicente
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France.
| | - Andrea Slézia
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - Antoine Ghestem
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
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6
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Clawson W, Vicente AF, Ferraris M, Bernard C, Battaglia D, Quilichini PP. Computing hubs in the hippocampus and cortex. Sci Adv 2019; 5:eaax4843. [PMID: 31249875 PMCID: PMC6594769 DOI: 10.1126/sciadv.aax4843] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 05/17/2019] [Indexed: 06/09/2023]
Abstract
Neural computation occurs within large neuron networks in the dynamic context of varying brain states. Whether functions are performed by specific subsets of neurons and whether they occur in specific dynamical regimes remain poorly understood. Using high-density recordings in the hippocampus, medial entorhinal, and medial prefrontal cortex of the rat, we identify computing substates where specific computing hub neurons perform well-defined storage and sharing operations in a brain state-dependent manner. We retrieve distinct computing substates within each global brain state, such as REM and nonREM sleep. Half of recorded neurons act as computing hubs in at least one substate, suggesting that functional roles are not hardwired but reassigned at the second time scale. We identify sequences of substates whose temporal organization is dynamic and stands between order and disorder. We propose that global brain states constrain the language of neuronal computations by regulating the syntactic complexity of substate sequences.
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7
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Pas J, Rutz AL, Quilichini PP, Slézia A, Ghestem A, Kaszas A, Donahue MJ, Curto VF, O’Connor RP, Bernard C, Williamson A, Malliaras GG. A bilayered PVA/PLGA-bioresorbable shuttle to improve the implantation of flexible neural probes. J Neural Eng 2018; 15:065001. [DOI: 10.1088/1741-2552/aadc1d] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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8
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Pas J, Pitsalidis C, Koutsouras DA, Quilichini PP, Santoro F, Cui B, Gallais L, O'Connor RP, Malliaras GG, Owens RM. Neurospheres on Patterned PEDOT:PSS Microelectrode Arrays Enhance Electrophysiology Recordings. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/adbi.201700164] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Jolien Pas
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
| | - Charalampos Pitsalidis
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
| | - Dimitrios A. Koutsouras
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
| | | | - Francesca Santoro
- Department of Chemistry; Stanford University; Stanford CA 94305 USA
- Center for Advanced Biomaterials for HealthCare; Italian Institute of Technology (IIT); Naples 80125 Italy
| | - Bianxiao Cui
- Department of Chemistry; Stanford University; Stanford CA 94305 USA
| | - Laurent Gallais
- Aix Marseille Univ; CNRS, Centrale Marseille; Institut Fresnel; 13397 Marseille Cedex 20 France
| | - Rodney P. O'Connor
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
| | - George G. Malliaras
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
- Electrical Engineering Division; University of Cambridge; Cambridge CB3 0AS UK
| | - Róisín M. Owens
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE; Gardanne 13541 France
- Department of Chemical Engineering and Biotechnology; University of Cambridge; Cambridge CB3 0FA UK
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9
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Uguz I, Ganji M, Hama A, Tanaka A, Inal S, Youssef A, Owens RM, Quilichini PP, Ghestem A, Bernard C, Dayeh SA, Malliaras GG. Autoclave Sterilization of PEDOT:PSS Electrophysiology Devices. Adv Healthc Mater 2016; 5:3094-3098. [PMID: 27885829 DOI: 10.1002/adhm.201600870] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Indexed: 11/06/2022]
Abstract
Autoclaving, the most widely available sterilization method, is applied to poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) electrophysiology devices. The process does not harm morphology or electrical properties, while it effectively kills E. coli intentionally cultured on the devices. This finding paves the way to widespread introduction of PEDOT:PSS electrophysiology devices to the clinic.
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Affiliation(s)
- Ilke Uguz
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE, MOC; 13541 Gardanne France
| | - Mehran Ganji
- Department of Electrical and Computer Engineering; Jacobs School of Engineering; University of California, San Diego; 9500 Gilman Drive La Jolla CA 92093-0407 USA
| | - Adel Hama
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE, MOC; 13541 Gardanne France
| | - Atsunori Tanaka
- Department of Electrical and Computer Engineering; Jacobs School of Engineering; University of California, San Diego; 9500 Gilman Drive La Jolla CA 92093-0407 USA
| | - Sahika Inal
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE, MOC; 13541 Gardanne France
| | - Ahmed Youssef
- Department of Electrical and Computer Engineering; Jacobs School of Engineering; University of California, San Diego; 9500 Gilman Drive La Jolla CA 92093-0407 USA
| | - Roisin M. Owens
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE, MOC; 13541 Gardanne France
| | - Pascale P. Quilichini
- Inserm U1106; Institut de Neurosciences des Systèmes; Aix Marseille University; 13005 Marseille France
| | - Antoine Ghestem
- Inserm U1106; Institut de Neurosciences des Systèmes; Aix Marseille University; 13005 Marseille France
| | - Christophe Bernard
- Inserm U1106; Institut de Neurosciences des Systèmes; Aix Marseille University; 13005 Marseille France
| | - Shadi A. Dayeh
- Department of Electrical and Computer Engineering; Jacobs School of Engineering; University of California, San Diego; 9500 Gilman Drive La Jolla CA 92093-0407 USA
| | - George G. Malliaras
- Department of Bioelectronics; Ecole Nationale Supérieure des Mines; CMP-EMSE, MOC; 13541 Gardanne France
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10
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Saillet S, Quilichini PP, Ghestem A, Giusiano B, Ivanov AI, Hitziger S, Vanzetta I, Bernard C, Bénar CG. Interneurons contribute to the hemodynamic/metabolic response to epileptiform discharges. J Neurophysiol 2015; 115:1157-69. [PMID: 26745250 DOI: 10.1152/jn.00994.2014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 12/21/2015] [Indexed: 01/28/2023] Open
Abstract
Interpretation of hemodynamic responses in epilepsy is hampered by an incomplete understanding of the underlying neurovascular coupling, especially the contributions of excitation and inhibition. We made simultaneous multimodal recordings of local field potentials (LFPs), firing of individual neurons, blood flow, and oxygen level in the somatosensory cortex of anesthetized rats. Epileptiform discharges induced by bicuculline injections were used to trigger large local events. LFP and blood flow were robustly coupled, as were LFP and tissue oxygen. In a parametric linear model, LFP and the baseline activities of cerebral blood flow and tissue partial oxygen tension contributed significantly to blood flow and oxygen responses. In an analysis of recordings from 402 neurons, blood flow/tissue oxygen correlated with the discharge of putative interneurons but not of principal cells. Our results show that interneuron activity is important in the vascular and metabolic responses during epileptiform discharges.
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Affiliation(s)
- Sandrine Saillet
- INSERM, UMR 1106, Marseille, France; Aix-Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France
| | - Pascale P Quilichini
- INSERM, UMR 1106, Marseille, France; Aix-Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France
| | - Antoine Ghestem
- INSERM, UMR 1106, Marseille, France; Aix-Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France
| | - Bernard Giusiano
- INSERM, UMR 1106, Marseille, France; Aix-Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France; APHM, Timone Hospital, Division of Public Health, Marseille, France
| | - Anton I Ivanov
- INSERM, UMR 1106, Marseille, France; Aix-Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France
| | | | - Ivo Vanzetta
- Aix-Marseille Université, CNRS, INT UMR 7289, Marseille, France
| | - Christophe Bernard
- INSERM, UMR 1106, Marseille, France; Aix-Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France
| | - Christian-G Bénar
- INSERM, UMR 1106, Marseille, France; Aix-Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France;
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11
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Wang HE, Bénar CG, Quilichini PP, Friston KJ, Jirsa VK, Bernard C. A systematic framework for functional connectivity measures. Front Neurosci 2014; 8:405. [PMID: 25538556 PMCID: PMC4260483 DOI: 10.3389/fnins.2014.00405] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 11/21/2014] [Indexed: 12/22/2022] Open
Abstract
Various methods have been proposed to characterize the functional connectivity between nodes in a network measured with different modalities (electrophysiology, functional magnetic resonance imaging etc.). Since different measures of functional connectivity yield different results for the same dataset, it is important to assess when and how they can be used. In this work, we provide a systematic framework for evaluating the performance of a large range of functional connectivity measures-based upon a comprehensive portfolio of models generating measurable responses. Specifically, we benchmarked 42 methods using 10,000 simulated datasets from 5 different types of generative models with different connectivity structures. Since all functional connectivity methods require the setting of some parameters (window size and number, model order etc.), we first optimized these parameters using performance criteria based upon (threshold free) ROC analysis. We then evaluated the performance of the methods on data simulated with different types of models. Finally, we assessed the performance of the methods against different levels of signal-to-noise ratios and network configurations. A MATLAB toolbox is provided to perform such analyses using other methods and simulated datasets.
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Affiliation(s)
- Huifang E Wang
- Institut de Neurosciences des Systèmes, Aix Marseille Université Marseille, France ; Institut national de la santé et de la recherche médicale, UMR_S 1106 Marseille, France
| | - Christian G Bénar
- Institut de Neurosciences des Systèmes, Aix Marseille Université Marseille, France ; Institut national de la santé et de la recherche médicale, UMR_S 1106 Marseille, France
| | - Pascale P Quilichini
- Institut de Neurosciences des Systèmes, Aix Marseille Université Marseille, France ; Institut national de la santé et de la recherche médicale, UMR_S 1106 Marseille, France
| | - Karl J Friston
- The Wellcome Trust Centre for Neuroimaging, University College London London, UK
| | - Viktor K Jirsa
- Institut de Neurosciences des Systèmes, Aix Marseille Université Marseille, France ; Institut national de la santé et de la recherche médicale, UMR_S 1106 Marseille, France
| | - Christophe Bernard
- Institut de Neurosciences des Systèmes, Aix Marseille Université Marseille, France ; Institut national de la santé et de la recherche médicale, UMR_S 1106 Marseille, France
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12
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Abstract
Seizures can occur spontaneously and in a recurrent manner, which defines epilepsy; or they can be induced in a normal brain under a variety of conditions in most neuronal networks and species from flies to humans. Such universality raises the possibility that invariant properties exist that characterize seizures under different physiological and pathological conditions. Here, we analysed seizure dynamics mathematically and established a taxonomy of seizures based on first principles. For the predominant seizure class we developed a generic model called Epileptor. As an experimental model system, we used ictal-like discharges induced in vitro in mouse hippocampi. We show that only five state variables linked by integral-differential equations are sufficient to describe the onset, time course and offset of ictal-like discharges as well as their recurrence. Two state variables are responsible for generating rapid discharges (fast time scale), two for spike and wave events (intermediate time scale) and one for the control of time course, including the alternation between 'normal' and ictal periods (slow time scale). We propose that normal and ictal activities coexist: a separatrix acts as a barrier (or seizure threshold) between these states. Seizure onset is reached upon the collision of normal brain trajectories with the separatrix. We show theoretically and experimentally how a system can be pushed toward seizure under a wide variety of conditions. Within our experimental model, the onset and offset of ictal-like discharges are well-defined mathematical events: a saddle-node and homoclinic bifurcation, respectively. These bifurcations necessitate a baseline shift at onset and a logarithmic scaling of interspike intervals at offset. These predictions were not only confirmed in our in vitro experiments, but also for focal seizures recorded in different syndromes, brain regions and species (humans and zebrafish). Finally, we identified several possible biophysical parameters contributing to the five state variables in our model system. We show that these parameters apply to specific experimental conditions and propose that there exists a wide array of possible biophysical mechanisms for seizure genesis, while preserving central invariant properties. Epileptor and the seizure taxonomy will guide future modeling and translational research by identifying universal rules governing the initiation and termination of seizures and predicting the conditions necessary for those transitions.
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Affiliation(s)
- Viktor K Jirsa
- 1 Aix Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France2 Inserm, UMR_S 1106, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - William C Stacey
- 3 Department of Neurology, Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Pascale P Quilichini
- 1 Aix Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France2 Inserm, UMR_S 1106, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Anton I Ivanov
- 1 Aix Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France2 Inserm, UMR_S 1106, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Christophe Bernard
- 1 Aix Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France2 Inserm, UMR_S 1106, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
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13
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Abstract
Neuronal firing pattern, which includes both the frequency and the timing of action potentials, is a key component of information processing in the brain. Although the relationship between neuronal output (the firing pattern) and function (during a task/behavior) is not fully understood, there is now considerable evidence that a given neuron can show very different firing patterns according to brain state. Thus, such neurons assembled into neuronal networks generate different rhythms (e.g., theta, gamma and sharp wave ripples), which sign specific brain states (e.g., learning, sleep). This implies that a given neuronal network, defined by its hard-wired physical connectivity, can support different brain state-dependent activities through the modulation of its functional connectivity. Here, we review data demonstrating that not only the firing pattern, but also the functional connections between neurons, can change dynamically. We then explore the possible mechanisms of such versatility, focusing on the intrinsic properties of neurons and the properties of the synapses they establish, and how they can be modified by neuromodulators, i.e., the different ways that neurons can use to switch from one mode of communication to the other.
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Affiliation(s)
- Pascale P Quilichini
- Aix Marseille Université, INS Marseille, France ; Inserm, UMR_S 1106 Marseille, France
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14
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Quilichini PP, Le Van Quyen M, Ivanov A, Turner DA, Carabalona A, Gozlan H, Esclapez M, Bernard C. Hub GABA neurons mediate gamma-frequency oscillations at ictal-like event onset in the immature hippocampus. Neuron 2012; 74:57-64. [PMID: 22500630 DOI: 10.1016/j.neuron.2012.01.026] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2012] [Indexed: 10/28/2022]
Abstract
Gamma-frequency oscillations (GFOs, >40 Hz) are a general network signature at seizure onset at all stages of development, with possible deleterious consequences in the immature brain. At early developmental stages, the simultaneous occurrence of GFOs in different brain regions suggests the existence of a long-ranging synchronizing mechanism at seizure onset. Here, we show that hippocamposeptal (HS) neurons, which are GABA long-range projection neurons, are mandatory to drive the firing of hippocampal interneurons in a high-frequency regime at the onset of epileptiform discharges in the intact, immature septohippocampal formation. The synchronized firing of interneurons in turn produces GFOs, which are abolished after the elimination of a small number of HS neurons. Because they provide the necessary fast conduit for pacing large neuronal populations and display intra- and extrahippocampal long-range projections, HS neurons appear to belong to the class of hub cells that play a crucial role in the synchronization of developing networks.
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Affiliation(s)
- Pascale P Quilichini
- Institut de Neurosciences des Systèmes, INSERM UMR1106, Faculté de Médecine La Timone, 27 Boulevard Jean Moulin, 13005 Marseille, France
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15
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Abstract
PURPOSE Stiripentol (STP) is currently an efficient drug for add-on therapy in infantile epilepsies because it improves the efficacy of antiepileptic drugs (AEDs) through its potent inhibition of liver cytochromes P450. In addition, STP directly reduces seizures in several animal models of epilepsy, suggesting that it might also have anticonvulsive effects of its own. However, its underlying mechanisms of action are unknown. METHODS We examined the interactions of STP with gamma-aminobutyric acid (GABA) transmission by using patch-clamp methods in CA3 pyramidal neurons in the neonatal rat. RESULTS STP markedly increased miniature inhibitory postsynaptic current (mIPSC) decay-time constant in a concentration-dependent manner. The prolongation of mIPSC duration does not result from an interaction with GABA transporters because it persisted in the presence of GAT-1 inhibitors (SKF-89976A and NO-711). An interaction with benzodiazepine or neurosteroid binding sites also was excluded because STP-mediated increase of decay time was still observed when these sites were initially saturated (by clobazam, zolpidem, or pregnanolone) or blocked (by flumazenil or dehydroepiandrosterone sulfate), respectively. In contrast, saturating barbiturate sites with pentobarbital clearly occluded this effect of STP, suggesting that STP and barbiturates interact at the same locus. This was directly confirmed by using outside-out patches, because STP increased the duration and not the frequency of opening of GABAA channels. CONCLUSIONS At clinically relevant concentrations, STP enhances central GABA transmission through a barbiturate-like effect, suggesting that STP should possess an antiepileptic effect by itself.
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16
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Abstract
We have determined the properties of seizures induced in vitro during the first postnatal days using intact rat cortico-hippocampal formations (CHFs) and extracellular recordings. Two main patterns of activity were generated by nominally Mg2+-free ACSF in hippocampal and cortical regions: ictal-like events (ILEs) and late recurrent interictal discharges (LRDs). They were elicited at distinct developmental periods and displayed different pharmacological properties. ILEs were first observed in P1 CHFs 52 +/- 7 min after application of low-Mg2+ ACSF (frequency 1.5 +/- 0.3 h-1, duration 86 +/- 3 s). There is a progressive age-dependent maturation of ILEs characterized by a decrease in their onset and an increase in their frequency and duration. ILEs were abolished by d-APV and Mg2+ ions. From P7, ILEs were followed by LRDs that appeared 89 +/- 8 min after application of low-Mg2+ ACSF (frequency approximately 1 Hz, duration 0.66 s, amplitude 0.31 +/- 0.03 mV). LRDs were no longer sensitive to d-APV or Mg2+ ions and persisted for at least 24 h in low-Mg2+ or in normal ACSF. ILEs and LRDs were synchronized in limbic and cortical regions with 10-40 ms latency between the onsets of seizures. Using a double chamber that enables independent superfusion of two interconnected CHFs, we report that ILEs and LRDs generated in one CHF propagated readily to the other one that was being kept in ACSF. Therefore, at a critical period of brain development, recurrent seizures induce a permanent form of hyperactivity in intact brain structures and this preparation provides a unique opportunity to study the consequences of seizures at early developmental stages.
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Affiliation(s)
- P P Quilichini
- INMED-INSERM Unité 29, 163, route de Luminy, BP 13, 13273 Marseille cedex 9, France
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