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Gulledge AT. Cholinergic Activation of Corticofugal Circuits in the Adult Mouse Prefrontal Cortex. J Neurosci 2024; 44:e1388232023. [PMID: 38050146 PMCID: PMC10860659 DOI: 10.1523/jneurosci.1388-23.2023] [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: 07/20/2023] [Revised: 10/10/2023] [Accepted: 11/08/2023] [Indexed: 12/06/2023] Open
Abstract
Acetylcholine (ACh) promotes neocortical output to the thalamus and brainstem by preferentially enhancing the postsynaptic excitability of layer 5 pyramidal tract (PT) neurons relative to neighboring intratelencephalic (IT) neurons. Less is known about how ACh regulates the excitatory synaptic drive of IT and PT neurons. To address this question, spontaneous excitatory postsynaptic potentials (sEPSPs) were recorded in dual recordings of IT and PT neurons in slices of prelimbic cortex from adult female and male mice. ACh (20 µM) enhanced sEPSP amplitudes, frequencies, rise-times, and half-widths preferentially in PT neurons. These effects were blocked by the muscarinic receptor antagonist atropine (1 µM). When challenged with pirenzepine (1 µM), an antagonist selective for M1-type muscarinic receptors, ACh instead reduced sEPSP frequencies, suggesting that ACh may generally suppress synaptic transmission in the cortex via non-M1 receptors. Cholinergic enhancement of sEPSPs in PT neurons was not sensitive to antagonism of GABA receptors with gabazine (10 µM) and CGP52432 (2.5 µM) but was blocked by tetrodotoxin (1 µM), suggesting that ACh enhances action-potential-dependent excitatory synaptic transmission in PT neurons. ACh also preferentially promoted the occurrence of synchronous sEPSPs in dual recordings of PT neurons relative to IT-PT and IT-IT parings. Finally, selective chemogenetic silencing of hM4Di-expressing PT, but not commissural IT, neurons blocked cholinergic enhancement of sEPSP amplitudes and frequencies in PT neurons. These data suggest that, in addition to selectively enhancing the postsynaptic excitability of PT neurons, M1 receptor activation promotes corticofugal output by amplifying recurrent excitation within networks of PT neurons.
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Affiliation(s)
- Allan T Gulledge
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth College, Hanover 03755, New Hampshire
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2
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Agopyan-Miu AH, Merricks EM, Smith EH, McKhann GM, Sheth SA, Feldstein NA, Trevelyan AJ, Schevon CA. Cell-type specific and multiscale dynamics of human focal seizures in limbic structures. Brain 2023; 146:5209-5223. [PMID: 37536281 PMCID: PMC10689922 DOI: 10.1093/brain/awad262] [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: 03/05/2023] [Revised: 06/30/2023] [Accepted: 07/19/2023] [Indexed: 08/05/2023] Open
Abstract
The relationship between clinically accessible epileptic biomarkers and neuronal activity underlying the transition to seizure is complex, potentially leading to imprecise delineation of epileptogenic brain areas. In particular, the pattern of interneuronal firing at seizure onset remains under debate, with some studies demonstrating increased firing and others suggesting reductions. Previous study of neocortical sites suggests that seizure recruitment occurs upon failure of inhibition, with intact feedforward inhibition in non-recruited territories. We investigated whether the same principle applies in limbic structures. We analysed simultaneous electrocorticography (ECoG) and neuronal recordings of 34 seizures in a cohort of 19 patients (10 male, 9 female) undergoing surgical evaluation for pharmacoresistant focal epilepsy. A clustering approach with five quantitative metrics computed from ECoG and multiunit data was used to distinguish three types of site-specific activity patterns during seizures, which at times co-existed within seizures. Overall, 156 single units were isolated, subclassified by cell-type and tracked through the seizure using our previously published methods to account for impacts of increased noise and single-unit waveshape changes caused by seizures. One cluster was closely associated with clinically defined seizure onset or spread. Entrainment of high-gamma activity to low-frequency ictal rhythms was the only metric that reliably identified this cluster at the level of individual seizures (P < 0.001). A second cluster demonstrated multi-unit characteristics resembling those in the first cluster, without concomitant high-gamma entrainment, suggesting feedforward effects from the seizure. The last cluster captured regions apparently unaffected by the ongoing seizure. Across all territories, the majority of both excitatory and inhibitory neurons reduced (69.2%) or ceased firing (21.8%). Transient increases in interneuronal firing rates were rare (13.5%) but showed evidence of intact feedforward inhibition, with maximal firing rate increases and waveshape deformations in territories not fully recruited but showing feedforward activity from the seizure, and a shift to burst-firing in seizure-recruited territories (P = 0.014). This study provides evidence for entrained high-gamma activity as an accurate biomarker of ictal recruitment in limbic structures. However, reduced neuronal firing suggested preserved inhibition in mesial temporal structures despite simultaneous indicators of seizure recruitment, in contrast to the inhibitory collapse scenario documented in neocortex. Further study is needed to determine if this activity is ubiquitous to hippocampal seizures or indicates a 'seizure-responsive' state in which the hippocampus is not the primary driver. If the latter, distinguishing such cases may help to refine the surgical treatment of mesial temporal lobe epilepsy.
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Affiliation(s)
- Alexander H Agopyan-Miu
- Department of Neurological Surgery, Columbia University Medical Center, NewYork, NY 10032, USA
| | - Edward M Merricks
- Department of Neurology, Columbia University Medical Center, NewYork, NY 10032, USA
| | - Elliot H Smith
- Department of Neurology, Columbia University Medical Center, NewYork, NY 10032, USA
- Department of Neurosurgery, University of Utah, Salt Lake City, UT 84132, USA
| | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Medical Center, NewYork, NY 10032, USA
| | - Sameer A Sheth
- Department of Neurosurgery, Baylor College of Medicine, Houston TX 77030, USA
| | - Neil A Feldstein
- Department of Neurological Surgery, Columbia University Medical Center, NewYork, NY 10032, USA
| | - Andrew J Trevelyan
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Catherine A Schevon
- Department of Neurology, Columbia University Medical Center, NewYork, NY 10032, USA
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Matovu D, Cavalheiro EA. Differences in Evolution of Epileptic Seizures and Topographical Distribution of Tissue Damage in Selected Limbic Structures Between Male and Female Rats Submitted to the Pilocarpine Model. Front Neurol 2022; 13:802587. [PMID: 35449517 PMCID: PMC9017681 DOI: 10.3389/fneur.2022.802587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 02/24/2022] [Indexed: 11/13/2022] Open
Abstract
Epidemiological evidence shows that clinical features and comorbidities in temporal lobe epilepsy (TLE) may have different manifestations depending on the sex of patients. However, little is known about how sex-related mechanisms can interfere with the processes underlying the epileptic phenomenon. The findings of this study show that male rats with epilepsy in the pilocarpine model have longer-lasting and more severe epileptic seizures, while female rats have a higher frequency of epileptic seizures and a greater number of seizure clusters. Significant sex-linked pathological changes were also observed: epileptic brains of male and female rats showed differences in mass reduction of 41.8% in the amygdala and 18.2% in the olfactory bulb, while loss of neuronal cells was present in the hippocampus (12.3%), amygdala (18.1%), and olfactory bulb (7.5%). Another important sex-related finding was the changes in non-neuronal cells with increments for the hippocampus (36.1%), amygdala (14.7%), and olfactory bulb (37%). Taken together, our study suggests that these neuropathological changes may underlie the differences in the clinical features of epileptic seizures observed in male and female rats.
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Affiliation(s)
- Daniel Matovu
- Neuroscience Laboratory, Department of Neurology and Neurosurgery, Escola Paulista de Medicina/UNIFESP, São Paulo, Brazil
| | - Esper A Cavalheiro
- Neuroscience Laboratory, Department of Neurology and Neurosurgery, Escola Paulista de Medicina/UNIFESP, São Paulo, Brazil
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Godoy LD, Prizon T, Rossignoli MT, Leite JP, Liberato JL. Parvalbumin Role in Epilepsy and Psychiatric Comorbidities: From Mechanism to Intervention. Front Integr Neurosci 2022; 16:765324. [PMID: 35250498 PMCID: PMC8891758 DOI: 10.3389/fnint.2022.765324] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 01/24/2022] [Indexed: 12/22/2022] Open
Abstract
Parvalbumin is a calcium-binding protein present in inhibitory interneurons that play an essential role in regulating many physiological processes, such as intracellular signaling and synaptic transmission. Changes in parvalbumin expression are deeply related to epilepsy, which is considered one of the most disabling neuropathologies. Epilepsy is a complex multi-factor group of disorders characterized by periods of hypersynchronous activity and hyperexcitability within brain networks. In this scenario, inhibitory neurotransmission dysfunction in modulating excitatory transmission related to the loss of subsets of parvalbumin-expressing inhibitory interneuron may have a prominent role in disrupted excitability. Some studies also reported that parvalbumin-positive interneurons altered function might contribute to psychiatric comorbidities associated with epilepsy, such as depression, anxiety, and psychosis. Understanding the epileptogenic process and comorbidities associated with epilepsy have significantly advanced through preclinical and clinical investigation. In this review, evidence from parvalbumin altered function in epilepsy and associated psychiatric comorbidities were explored with a translational perspective. Some advances in potential therapeutic interventions are highlighted, from current antiepileptic and neuroprotective drugs to cutting edge modulation of parvalbumin subpopulations using optogenetics, designer receptors exclusively activated by designer drugs (DREADD) techniques, transcranial magnetic stimulation, genome engineering, and cell grafting. Creating new perspectives on mechanisms and therapeutic strategies is valuable for understanding the pathophysiology of epilepsy and its psychiatric comorbidities and improving efficiency in clinical intervention.
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Affiliation(s)
- Lívea Dornela Godoy
- Department of Psychology, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Tamiris Prizon
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Matheus Teixeira Rossignoli
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - João Pereira Leite
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
- João Pereira Leite,
| | - José Luiz Liberato
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
- *Correspondence: José Luiz Liberato,
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Yokoi R, Shigemoto-Kuroda T, Matsuda N, Odawara A, Suzuki I. Electrophysiological responses to seizurogenic compounds dependent on E/I balance in human iPSC-derived cortical neural networks. J Pharmacol Sci 2022; 148:267-278. [DOI: 10.1016/j.jphs.2021.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/18/2021] [Accepted: 12/27/2021] [Indexed: 10/19/2022] Open
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Sayahi Z, Komaki A, Saidi Jam M, Karimi SA, Raoufi S, Mardani P, Naderishahab M, Sarihi A, Mirnajafi-Zadeh J. Effect of ramosetron, a 5-HT 3 receptor antagonist on the severity of seizures and memory impairment in electrical amygdala kindled rats. J Physiol Sci 2022; 72:1. [PMID: 35034601 PMCID: PMC10717980 DOI: 10.1186/s12576-022-00825-5] [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: 03/16/2021] [Accepted: 01/04/2022] [Indexed: 11/10/2022]
Abstract
The entorhinal cortex (EC) plays a pivotal role in epileptogenesis and seizures. EC expresses high density of serotonergic receptors, especially 5-HT3 receptors. Cognitive impairment is common among people with epilepsy. The present study investigated the role of 5-HT3 receptor on the severity of seizures and learning and memory impairment by electrical kindling of amygdala in rats. The amygdala kindling was conducted in a chronic kindling manner in male Wistar rats. In fully kindled animals, ramosetron (as a potent and selective 5-HT3 receptor antagonist) was microinjected unilaterally (ad doses of 1, 10 or 100 µg/0.5 µl) into the EC 5 min before the novel object recognition (NOR) and Y-maze tests or kindling stimulations. Applying ramosetron at the concentration of 100 μg/0.5 µl (but not at 1 and 10 µg/0.5 µl) reduced afterdischarge (AD) duration and increased stage 4 latency in the kindled rats. Moreover, the obtained data from the NOR test showed that treatment by ramosetron (10 and 100 µg/0.5 µl) increased the discrimination index in the fully kindled animals. Microinjection of ramosetron (10 and 100 µg/0.5 µl) in fully kindled animals reversed the kindling induced changes in the percentage of spontaneous alternation in Y-maze task. The findings demonstrated an anticonvulsant role for a selective 5-HT3 receptor antagonist microinjected into the EC, therefore, suggesting an excitatory role for the EC 5-HT3 receptors in the amygdala kindling model of epilepsy. This anticonvulsive effect was accompanied with a restoring effect on cognitive behavior in NOR and Y-maze tests.
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Affiliation(s)
- Zeynab Sayahi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran
- Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Masoud Saidi Jam
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Seyed Asaad Karimi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran
- Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Safoura Raoufi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran
| | - Parastoo Mardani
- Department of Biology, Faculty of Sciences, Payame Noor University, Sanandaj, Iran
| | - Marzieh Naderishahab
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran
| | - Abdolrahman Sarihi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran.
- Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, 1411713116, Tehran, Iran.
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Barbero‐Castillo A, Riefolo F, Matera C, Caldas‐Martínez S, Mateos‐Aparicio P, Weinert JF, Garrido‐Charles A, Claro E, Sanchez‐Vives MV, Gorostiza P. Control of Brain State Transitions with a Photoswitchable Muscarinic Agonist. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2005027. [PMID: 34018704 PMCID: PMC8292914 DOI: 10.1002/advs.202005027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/19/2021] [Indexed: 05/03/2023]
Abstract
The ability to control neural activity is essential for research not only in basic neuroscience, as spatiotemporal control of activity is a fundamental experimental tool, but also in clinical neurology for therapeutic brain interventions. Transcranial-magnetic, ultrasound, and alternating/direct current (AC/DC) stimulation are some available means of spatiotemporal controlled neuromodulation. There is also light-mediated control, such as optogenetics, which has revolutionized neuroscience research, yet its clinical translation is hampered by the need for gene manipulation. As a drug-based light-mediated control, the effect of a photoswitchable muscarinic agonist (Phthalimide-Azo-Iper (PAI)) on a brain network is evaluated in this study. First, the conditions to manipulate M2 muscarinic receptors with light in the experimental setup are determined. Next, physiological synchronous emergent cortical activity consisting of slow oscillations-as in slow wave sleep-is transformed into a higher frequency pattern in the cerebral cortex, both in vitro and in vivo, as a consequence of PAI activation with light. These results open the way to study cholinergic neuromodulation and to control spatiotemporal patterns of activity in different brain states, their transitions, and their links to cognition and behavior. The approach can be applied to different organisms and does not require genetic manipulation, which would make it translational to humans.
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Affiliation(s)
| | - Fabio Riefolo
- Institute for Bioengineering of Catalonia (IBEC)The Barcelona Institute for Science and TechnologyBarcelona08028Spain
- Network Biomedical Research Center in BioengineeringBiomaterials, and Nanomedicine (CIBER‐BBN)Madrid28029Spain
| | - Carlo Matera
- Institute for Bioengineering of Catalonia (IBEC)The Barcelona Institute for Science and TechnologyBarcelona08028Spain
- Network Biomedical Research Center in BioengineeringBiomaterials, and Nanomedicine (CIBER‐BBN)Madrid28029Spain
- Department of Pharmaceutical SciencesUniversity of MilanMilan20133Italy
| | - Sara Caldas‐Martínez
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)Barcelona08036Spain
| | - Pedro Mateos‐Aparicio
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)Barcelona08036Spain
| | - Julia F. Weinert
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)Barcelona08036Spain
| | - Aida Garrido‐Charles
- Institute for Bioengineering of Catalonia (IBEC)The Barcelona Institute for Science and TechnologyBarcelona08028Spain
- Network Biomedical Research Center in BioengineeringBiomaterials, and Nanomedicine (CIBER‐BBN)Madrid28029Spain
| | - Enrique Claro
- Institut de Neurociències and Departament de Bioquímica i Biologia MolecularUnitat de Bioquímica de MedicinaUniversitat Autònoma de Barcelona (UAB)Barcelona08193Spain
| | - Maria V. Sanchez‐Vives
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)Barcelona08036Spain
- Catalan Institution for Research and Advanced Studies (ICREA)Barcelona08010Spain
| | - Pau Gorostiza
- Institute for Bioengineering of Catalonia (IBEC)The Barcelona Institute for Science and TechnologyBarcelona08028Spain
- Network Biomedical Research Center in BioengineeringBiomaterials, and Nanomedicine (CIBER‐BBN)Madrid28029Spain
- Catalan Institution for Research and Advanced Studies (ICREA)Barcelona08010Spain
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Wang Y, Tan B, Wang Y, Chen Z. Cholinergic Signaling, Neural Excitability, and Epilepsy. Molecules 2021; 26:molecules26082258. [PMID: 33924731 PMCID: PMC8070422 DOI: 10.3390/molecules26082258] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/09/2021] [Accepted: 04/11/2021] [Indexed: 11/16/2022] Open
Abstract
Epilepsy is a common brain disorder characterized by recurrent epileptic seizures with neuronal hyperexcitability. Apart from the classical imbalance between excitatory glutamatergic transmission and inhibitory γ-aminobutyric acidergic transmission, cumulative evidence suggest that cholinergic signaling is crucially involved in the modulation of neural excitability and epilepsy. In this review, we briefly describe the distribution of cholinergic neurons, muscarinic, and nicotinic receptors in the central nervous system and their relationship with neural excitability. Then, we summarize the findings from experimental and clinical research on the role of cholinergic signaling in epilepsy. Furthermore, we provide some perspectives on future investigation to reveal the precise role of the cholinergic system in epilepsy.
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Affiliation(s)
- Yu Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 310053, China; (Y.W.); (B.T.)
| | - Bei Tan
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 310053, China; (Y.W.); (B.T.)
| | - Yi Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 310053, China; (Y.W.); (B.T.)
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China
- Correspondence: (Y.W.); (Z.C.); Tel.: +86-5718-661-8660 (Z.C.)
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 310053, China; (Y.W.); (B.T.)
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China
- Correspondence: (Y.W.); (Z.C.); Tel.: +86-5718-661-8660 (Z.C.)
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Grosser S, Buck N, Braunewell KH, Gilling KE, Wozny C, Fidzinski P, Behr J. Loss of Long-Term Potentiation at Hippocampal Output Synapses in Experimental Temporal Lobe Epilepsy. Front Mol Neurosci 2020; 13:143. [PMID: 32982687 PMCID: PMC7484482 DOI: 10.3389/fnmol.2020.00143] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/13/2020] [Indexed: 11/24/2022] Open
Abstract
Patients suffering from temporal lobe epilepsy (TLE) show severe problems in hippocampus dependent memory consolidation. Memory consolidation strongly depends on an intact dialog between the hippocampus and neocortical structures. Deficits in hippocampal signal transmission are known to provoke disturbances in memory formation. In the present study, we investigate changes of synaptic plasticity at hippocampal output structures in an experimental animal model of TLE. In pilocarpine-treated rats, we found suppressed long-term potentiation (LTP) in hippocampal and parahippocampal regions such as the subiculum and the entorhinal cortex (EC). Subsequently we focused on the subiculum, serving as the major relay station between the hippocampus proper and downstream structures. In control animals, subicular pyramidal cells express different forms of LTP depending on their intrinsic firing pattern. In line with our extracellular recordings, we could show that LTP could only be induced in a minority of subicular pyramidal neurons. We demonstrate that a well-characterized cAMP-dependent signaling pathway involved in presynaptic forms of LTP is perturbed in pilocarpine-treated animals. Our findings suggest that in TLE, disturbances of synaptic plasticity may influence the information flow between the hippocampus and the neocortex.
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Affiliation(s)
- Sabine Grosser
- Institute of Integrative Neuroanatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Nadine Buck
- Department of Anesthesiology and Intensive Care Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Karl-Heinz Braunewell
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
| | - Kate E Gilling
- Department of Psychiatry and Psychotherapy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Christian Wozny
- Strathclyde Institute of Pharmacy and Biomedical Sciences, Faculty of Science, University of Strathclyde, Glasgow, United Kingdom
| | - Pawel Fidzinski
- Department of Neurology with Experimental Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Joachim Behr
- Department of Psychiatry and Psychotherapy, Brandenburg Medical School, Neuruppin, Germany.,Department of Psychiatry and Psychotherapy, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Silkis IG. Role of Acetylcholine and GABAergic Inhibitory Transmission in Seizure Pattern Generation in Neural Networks Integrating the Neocortex, Hippocampus, Basal Ganglia, and Thalamus. NEUROCHEM J+ 2020. [DOI: 10.1134/s1819712420020129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Wang Y, Wang Y, Xu C, Wang S, Tan N, Chen C, Chen L, Wu X, Fei F, Cheng H, Lin W, Qi Y, Chen B, Liang J, Zhao J, Xu Z, Guo Y, Zhang S, Li X, Zhou Y, Duan S, Chen Z. Direct Septum-Hippocampus Cholinergic Circuit Attenuates Seizure Through Driving Somatostatin Inhibition. Biol Psychiatry 2020; 87:843-856. [PMID: 31987494 DOI: 10.1016/j.biopsych.2019.11.014] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/24/2019] [Accepted: 11/12/2019] [Indexed: 11/27/2022]
Abstract
BACKGROUND Previous studies indicated the involvement of cholinergic neurons in seizure; however, the specific role of the medial septum (MS)-hippocampus cholinergic circuit in temporal lobe epilepsy (TLE) has not yet been completely elucidated. METHODS In the current study, we used magnetic resonance imaging and diffusion tensor imaging to characterize the pathological change of the MS-hippocampus circuit in 42 patients with TLE compared with 22 healthy volunteers. Using optogenetics and chemogenetics, combined with in vivo or in vitro electrophysiology and retrograde rabies virus tracing, we revealed a direct MS-hippocampus cholinergic circuit that potently attenuates seizure through driving somatostatin inhibition in animal TLE models. RESULTS We found that patients with TLE with hippocampal sclerosis showed a decrease of neuronal fiber connectivity of the MS-hippocampus compared with healthy people. In the mouse TLE model, MS cholinergic neurons ceased firing during hippocampal seizures. Optogenetic and chemogenetic activation of MS cholinergic neurons (but not glutamatergic or GABAergic [gamma-aminobutyric acidergic] neurons) significantly attenuated hippocampal seizures, while specific inhibition promoted hippocampal seizures. Electrophysiology combined with modified rabies virus tracing studies showed that direct (but not indirect) MS-hippocampal cholinergic projections mediated the antiseizure effect by preferentially targeting hippocampal GABAergic neurons. Furthermore, chemogenetic inhibition of hippocampal somatostatin-positive (rather than parvalbumin-positive) subtype of GABAergic neurons reversed the antiseizure effect of the MS-hippocampus cholinergic circuit, which was mimicked by activating somatostatin-positive neurons. CONCLUSIONS These findings underscore the notable antiseizure role of the direct cholinergic MS-hippocampus circuit in TLE through driving the downstream somatostatin effector. This may provide a better understanding of the changes of the seizure circuit and the precise spatiotemporal control of epilepsy.
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Affiliation(s)
- Ying Wang
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yi Wang
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China; Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China.
| | - Cenglin Xu
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China; Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shuang Wang
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Na Tan
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Cong Chen
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Liying Chen
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Xiaohua Wu
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Fan Fei
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Heming Cheng
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Wenkai Lin
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yingbei Qi
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Bin Chen
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Jiao Liang
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Junli Zhao
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Zhenghao Xu
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yi Guo
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shihong Zhang
- Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaoming Li
- Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yudong Zhou
- Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shumin Duan
- Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Zhong Chen
- Institute of Pharmacology and Toxicology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China; Institute of Neuroscience, Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
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Abstract
Paradoxical Effects of Optogenetic Stimulation in Mesial Temporal Lobe Epilepsy Levesque M, Chen LY, Etter G, et al. Ann Neurol. 2019;86(5):714-728. doi:10.1002/ana.25572. Objective: To establish the effects induced by long-term, unilateral stimulation of parvalbumin (PV)-positive interneurons on seizures, interictal spikes, and high-frequency oscillations (80-500 Hz) occurring after pilocarpine-induced status epilepticus (SE)—a proven model of mesial temporal lobe epilepsy (MTLE)—in transgenic mice expressing or not expressing ChR2. Methods: Both PV-ChR2 (n = 6) and PV-Cre (n = 6) mice were treated with pilocarpine to induce SE. Three hours after SE onset, unilateral optogenetic stimulation (450 nm, 25 mW, 20 ms pulses delivered at 8 Hz for 30 seconds every 2 minutes) of CA3 PV-positive interneurons was implemented for 14 continuous days in both groups. Results: Rates of seizures (P < .01), interictal spikes (P < .001), and interictal spikes with fast ripples (250-500 Hz; P < .001) were lower in PV-ChR2 than in PV-Cre mice. Ripples (80-200 Hz) occurring outside of interictal spikes had higher rates in the PV-ChR2 group (P < .01), whereas isolated fast ripples had lower rates (P < .01). However, seizure probability was higher during optogenetic stimulation in PV-ChR2 compared to PV-Cre animals (P < .05). Interpretation: Our findings show that the unilateral activation of CA3 PV-positive interneurons exerts anti-ictogenic effects associated with decreased rates of interictal spikes and fast ripples in this MTLE model. However, PV-positive interneuron stimulation can paradoxically trigger seizures in epileptic animals, supporting the notion that γ-aminobutyric acid type A signaling can also initiate ictogenesis.
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Voltage-Dependent Calcium Channels, Calcium Binding Proteins, and Their Interaction in the Pathological Process of Epilepsy. Int J Mol Sci 2018; 19:ijms19092735. [PMID: 30213136 PMCID: PMC6164075 DOI: 10.3390/ijms19092735] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/06/2018] [Accepted: 09/07/2018] [Indexed: 01/08/2023] Open
Abstract
As an important second messenger, the calcium ion (Ca2+) plays a vital role in normal brain function and in the pathophysiological process of different neurodegenerative diseases including Alzheimer’s disease (AD), Parkinson’s disease (PD), and epilepsy. Ca2+ takes part in the regulation of neuronal excitability, and the imbalance of intracellular Ca2+ is a trigger factor for the occurrence of epilepsy. Several anti-epileptic drugs target voltage-dependent calcium channels (VDCCs). Intracellular Ca2+ levels are mainly controlled by VDCCs located in the plasma membrane, the calcium-binding proteins (CBPs) inside the cytoplasm, calcium channels located on the intracellular calcium store (particular the endoplasmic reticulum/sarcoplasmic reticulum), and the Ca2+-pumps located in the plasma membrane and intracellular calcium store. So far, while many studies have established the relationship between calcium control factors and epilepsy, the mechanism of various Ca2+ regulatory factors in epileptogenesis is still unknown. In this paper, we reviewed the function, distribution, and alteration of VDCCs and CBPs in the central nervous system in the pathological process of epilepsy. The interaction of VDCCs with CBPs in the pathological process of epilepsy was also summarized. We hope this review can provide some clues for better understanding the mechanism of epileptogenesis, and for the development of new anti-epileptic drugs targeting on VDCCs and CBPs.
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Tikhonova TB, Miyamae T, Gulchina Y, Lewis DA, Gonzalez-Burgos G. Cell Type- and Layer-Specific Muscarinic Potentiation of Excitatory Synaptic Drive onto Parvalbumin Neurons in Mouse Prefrontal Cortex. eNeuro 2018; 5:ENEURO.0208-18.2018. [PMID: 30713994 PMCID: PMC6354785 DOI: 10.1523/eneuro.0208-18.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 10/16/2018] [Accepted: 10/22/2018] [Indexed: 01/19/2023] Open
Abstract
Cholinergic neuromodulation is thought to shape network activity in the PFC, and thus PFC-dependent cognitive functions. ACh may modulate the activity of parvalbumin-positive (PV+) neurons, which critically regulate cortical network function. However, the mechanisms of cholinergic regulation of PV+ neuron activity, and particularly of the basket cell (BC) versus chandelier cell (ChC) subtypes, are unclear. Using patch clamp recordings in acute slices, we examined the effects of the ACh receptor (AChR) agonist carbachol on the excitatory synaptic drive onto BCs or ChCs in layers 2 to 6 of mouse PFC. Carbachol increased the frequency and amplitude of spontaneous EPSCs (sEPSCs) recorded from PV+ BCs in layers 3-6, but not in BCs from layer 2. Moreover, carbachol did not change the sEPSCs in ChCs, which were located exclusively in layer 2. The potentiation of sEPSCs in layers 3-6 BCs was prevented by the Na+ channel blocker tetrodotoxin and was abolished by the M1-selective muscarinic AChR antagonist pirenzepine. Thus, carbachol potentiates the activity-dependent excitatory drive onto PV+ neurons via M1-muscarinic AChR activation in a cell type- and layer-specific manner. In current clamp recordings with synaptic transmission blocked, carbachol directly evoked firing in deep layer pyramidal neurons (PNs). In contrast, carbachol elicited deep layer BC firing indirectly, via glutamate-mediated synaptic drive. Our data suggest that ACh powerfully regulates PFC microcircuit function by facilitating the firing of PNs that synaptically recruit deep layer PV+ BC activity, possibly shaping the patterns of network activity that contribute to cognitive function.
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Affiliation(s)
- Tatiana B Tikhonova
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Takeaki Miyamae
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Yelena Gulchina
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - David A Lewis
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Guillermo Gonzalez-Burgos
- Translational Neuroscience Program, Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
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15
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Bradley SJ, Tobin AB, Prihandoko R. The use of chemogenetic approaches to study the physiological roles of muscarinic acetylcholine receptors in the central nervous system. Neuropharmacology 2018; 136:421-426. [PMID: 29191752 DOI: 10.1016/j.neuropharm.2017.11.043] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 10/12/2017] [Accepted: 11/26/2017] [Indexed: 12/19/2022]
Abstract
Chemical genetic has played an important role in linking specific G protein-coupled receptor (GPCR) signalling to cellular processes involved in central nervous system (CNS) functions. Key to this approach has been the modification of receptor properties such that receptors no longer respond to endogenous ligands but rather can be activated selectively by synthetic ligands. Such modified receptors have been called Receptors Activated Solely by Synthetic Ligands (RASSLs) or Designer Receptors Exclusively Activated by Designer Drugs (DREADDs). Unlike knock-out animal models which allow detection of phenotypic changes caused by loss of receptor functions, RASSL and DREADD receptors offer the possibility of rescuing "knock-out" phenotypic deficits by administration of the synthetic ligands. Here we describe the use of these modified receptors in defining the physiological role of GPCRs and validation of receptors as drug targets. This article is part of the Special Issue entitled 'Neuropharmacology on Muscarinic Receptors'.
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Affiliation(s)
- Sophie J Bradley
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Andrew B Tobin
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Rudi Prihandoko
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
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Christenson Wick Z, Krook-Magnuson E. Specificity, Versatility, and Continual Development: The Power of Optogenetics for Epilepsy Research. Front Cell Neurosci 2018; 12:151. [PMID: 29962936 PMCID: PMC6010559 DOI: 10.3389/fncel.2018.00151] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 05/15/2018] [Indexed: 12/19/2022] Open
Abstract
Optogenetics is a powerful and rapidly expanding set of techniques that use genetically encoded light sensitive proteins such as opsins. Through the selective expression of these exogenous light-sensitive proteins, researchers gain the ability to modulate neuronal activity, intracellular signaling pathways, or gene expression with spatial, directional, temporal, and cell-type specificity. Optogenetics provides a versatile toolbox and has significantly advanced a variety of neuroscience fields. In this review, using recent epilepsy research as a focal point, we highlight how the specificity, versatility, and continual development of new optogenetic related tools advances our understanding of neuronal circuits and neurological disorders. We additionally provide a brief overview of some currently available optogenetic tools including for the selective expression of opsins.
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Affiliation(s)
- Zoé Christenson Wick
- Graduate Program in Neuroscience and Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
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Pelkey KA, Chittajallu R, Craig MT, Tricoire L, Wester JC, McBain CJ. Hippocampal GABAergic Inhibitory Interneurons. Physiol Rev 2017; 97:1619-1747. [PMID: 28954853 DOI: 10.1152/physrev.00007.2017] [Citation(s) in RCA: 495] [Impact Index Per Article: 70.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/16/2017] [Accepted: 05/26/2017] [Indexed: 12/11/2022] Open
Abstract
In the hippocampus GABAergic local circuit inhibitory interneurons represent only ~10-15% of the total neuronal population; however, their remarkable anatomical and physiological diversity allows them to regulate virtually all aspects of cellular and circuit function. Here we provide an overview of the current state of the field of interneuron research, focusing largely on the hippocampus. We discuss recent advances related to the various cell types, including their development and maturation, expression of subtype-specific voltage- and ligand-gated channels, and their roles in network oscillations. We also discuss recent technological advances and approaches that have permitted high-resolution, subtype-specific examination of their roles in numerous neural circuit disorders and the emerging therapeutic strategies to ameliorate such pathophysiological conditions. The ultimate goal of this review is not only to provide a touchstone for the current state of the field, but to help pave the way for future research by highlighting where gaps in our knowledge exist and how a complete appreciation of their roles will aid in future therapeutic strategies.
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Affiliation(s)
- Kenneth A Pelkey
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Ramesh Chittajallu
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Michael T Craig
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Ludovic Tricoire
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Jason C Wester
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
| | - Chris J McBain
- Porter Neuroscience Center, Eunice Kennedy-Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Hatherly Laboratories, University of Exeter, Exeter, United Kingdom; and Sorbonne Universités, UPMC University of Paris, INSERM, CNRS, Neurosciences Paris Seine-Institut de Biologie Paris Seine, Paris, France
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Kim CM, Nykamp DQ. The influence of depolarization block on seizure-like activity in networks of excitatory and inhibitory neurons. J Comput Neurosci 2017; 43:65-79. [PMID: 28528529 DOI: 10.1007/s10827-017-0647-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 03/11/2017] [Accepted: 04/26/2017] [Indexed: 11/29/2022]
Abstract
The inhibitory restraint necessary to suppress aberrant activity can fail when inhibitory neurons cease to generate action potentials as they enter depolarization block. We investigate possible bifurcation structures that arise at the onset of seizure-like activity resulting from depolarization block in inhibitory neurons. Networks of conductance-based excitatory and inhibitory neurons are simulated to characterize different types of transitions to the seizure state, and a mean field model is developed to verify the generality of the observed phenomena of excitatory-inhibitory dynamics. Specifically, the inhibitory population's activation function in the Wilson-Cowan model is modified to be non-monotonic to reflect that inhibitory neurons enter depolarization block given strong input. We find that a physiological state and a seizure state can coexist, where the seizure state is characterized by high excitatory and low inhibitory firing rate. Bifurcation analysis of the mean field model reveals that a transition to the seizure state may occur via a saddle-node bifurcation or a homoclinic bifurcation. We explain the hysteresis observed in network simulations using these two bifurcation types. We also demonstrate that extracellular potassium concentration affects the depolarization block threshold; the consequent changes in bifurcation structure enable the network to produce the tonic to clonic phase transition observed in biological epileptic networks.
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Affiliation(s)
- Christopher M Kim
- School of Mathematics, University of Minnesota, Minneapolis, MN, USA. .,Laboratory of Biological Modeling, NIDDK, National Institute of Health, Bethesda, MD, USA.
| | - Duane Q Nykamp
- School of Mathematics, University of Minnesota, Minneapolis, MN, USA
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Synapsin II Regulation of GABAergic Synaptic Transmission Is Dependent on Interneuron Subtype. J Neurosci 2017; 37:1757-1771. [PMID: 28087765 DOI: 10.1523/jneurosci.0844-16.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 12/22/2016] [Accepted: 12/31/2016] [Indexed: 11/21/2022] Open
Abstract
Synapsins are epilepsy susceptibility genes that encode phosphoproteins reversibly associated with synaptic vesicles. Synapsin II (SynII) gene deletion produces a deficit in inhibitory synaptic transmission, and this defect is thought to cause epileptic activity. We systematically investigated how SynII affects synchronous and asynchronous release components of inhibitory transmission in the CA1 region of the mouse hippocampus. We found that the asynchronous GABAergic release component is diminished in SynII-deleted (SynII(-)) slices. To investigate this defect at different interneuron subtypes, we selectively blocked either N-type or P/Q-type Ca2+ channels. SynII deletion suppressed the asynchronous release component at synapses dependent on N-type Ca2+ channels but not at synapses dependent on P/Q-type Ca2+ channels. We then performed paired double-patch recordings from inhibitory basket interneurons connected to pyramidal neurons and used cluster analysis to classify interneurons according to their spiking and synaptic parameters. We identified two cell subtypes, presumably parvalbumin (PV) and cholecystokinin (CCK) expressing basket interneurons. To validate our interneuron classification, we took advantage of transgenic animals with fluorescently labeled PV interneurons and confirmed that their spiking and synaptic parameters matched the parameters of presumed PV cells identified by the cluster analysis. The analysis of the release time course at the two interneuron subtypes demonstrated that the asynchronous release component was selectively reduced at SynII(-) CCK interneurons. In contrast, the transmission was desynchronized at SynII(-) PV interneurons. Together, our results demonstrate that SynII regulates the time course of GABAergic release, and that this SynII function is dependent on the interneuron subtype.SIGNIFICANCE STATEMENT Deletion of the neuronal protein synapsin II (SynII) leads to the development of epilepsy, probably due to impairments in inhibitory synaptic transmission. We systematically investigated SynII function at different subtypes of inhibitory neurons in the hippocampus. We discovered that SynII affects the time course of GABA release, and that this effect is interneuron subtype specific. Within one of the subtypes, SynII deficiency synchronizes the release and suppresses the asynchronous release component, while at the other subtype SynII deficiency suppresses the synchronous release component. These results reveal a new SynII function in the regulation of the time course of GABA release and demonstrate that this function is dependent on the interneuron subtype.
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Altered Oscillatory Dynamics of CA1 Parvalbumin Basket Cells during Theta-Gamma Rhythmopathies of Temporal Lobe Epilepsy. eNeuro 2016; 3:eN-NWR-0284-16. [PMID: 27896315 PMCID: PMC5114702 DOI: 10.1523/eneuro.0284-16.2016] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 10/25/2016] [Accepted: 10/25/2016] [Indexed: 12/23/2022] Open
Abstract
Recent reports in human demonstrate a role of theta–gamma coupling in memory for spatial episodes and a lack of coupling in people experiencing temporal lobe epilepsy, but the mechanisms are unknown. Using multisite silicon probe recordings of epileptic rats engaged in episodic-like object recognition tasks, we sought to evaluate the role of theta–gamma coupling in the absence of epileptiform activities. Our data reveal a specific association between theta–gamma (30–60 Hz) coupling at the proximal stratum radiatum of CA1 and spatial memory deficits. We targeted the microcircuit mechanisms with a novel approach to identify putative interneuronal types in tetrode recordings (parvalbumin basket cells in particular) and validated classification criteria in the epileptic context with neurochemical identification of intracellularly recorded cells. In epileptic rats, putative parvalbumin basket cells fired poorly modulated at the falling theta phase, consistent with weaker inputs from Schaffer collaterals and attenuated gamma oscillations, as evaluated by theta-phase decomposition of current–source density signals. We propose that theta–gamma interneuronal rhythmopathies of the temporal lobe are intimately related to episodic memory dysfunction in this condition.
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Assaf F, Schiller Y. The antiepileptic and ictogenic effects of optogenetic neurostimulation of PV-expressing interneurons. J Neurophysiol 2016; 116:1694-1704. [PMID: 27486107 DOI: 10.1152/jn.00744.2015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 07/13/2016] [Indexed: 11/22/2022] Open
Abstract
Parvalbumin (PV)-expressing interneurons exert powerful inhibitory effects on the normal cortical network; thus optogenetic activation of PV interneurons may also possess antiepileptic properties. To investigate this possibility we expressed channelrhodopsin 2 in PV interneurons by locally injecting the Cre-dependent viral vector AAV2/1-EF1a-DIO-ChETA-EYFP into the S1 barrel cortex of PV-Cre mice. Approximately 3-4 wk later recurrent electrographic seizures were evoked by local application of the chemoconvulsant 4-aminopyridine (4-AP); the ECoG and unit activity were monitored with extracellular silicone electrodes; and PV interneurons were activated optogenetically during the ictal and interictal phases. Five- to ten-second optogenetic activation of PV interneurons applied during electrographic seizures (ictal phase) terminated 33.7% of electrographic seizures compared with only 6% during sham stimulation, and the average electrographic seizure duration shortened by 38.7 ± 34.2% compared with sham stimulation. In contrast, interictal optogenetic activation of PV interneurons showed powerful and robust ictogenic effects. Approximately 60% of interictal optogenetic stimuli resulted in electrographic seizure initiation. Single-unit recordings revealed that presumptive PV-expressing interneurons markedly increased their firing during optogenetic stimulation, while many presumptive excitatory pyramidal neurons showed a biphasic response, with initial suppression of firing during the optogenetic pulse followed by a synchronized rebound increase in firing at the end of the laser pulse. Our findings indicated that ictal activation of PV-expressing interneurons possesses antiepileptic properties probably due to suppression of firing in pyramidal neurons during the laser pulse. However, in addition interictal activation of PV-expressing interneurons possesses powerful ictogenic properties, probably due to synchronized postinhibition rebound firing of pyramidal neurons.
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Affiliation(s)
- Fadi Assaf
- The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel; and
| | - Yitzhak Schiller
- The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel; and Department of Neurology, Rambam Medical Center, Haifa, Israel
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Jiang X, Lachance M, Rossignol E. Involvement of cortical fast-spiking parvalbumin-positive basket cells in epilepsy. PROGRESS IN BRAIN RESEARCH 2016; 226:81-126. [PMID: 27323940 DOI: 10.1016/bs.pbr.2016.04.012] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
GABAergic interneurons of the parvalbumin-positive fast-spiking basket cells subtype (PV INs) are important regulators of cortical network excitability and of gamma oscillations, involved in signal processing and cognition. Impaired development or function of PV INs has been associated with epilepsy in various animal models of epilepsy, as well as in some genetic forms of epilepsy in humans. In this review, we provide an overview of some of the experimental data linking PV INs dysfunction with epilepsy, focusing on disorders of the specification, migration, maturation, synaptic function, or connectivity of PV INs. Furthermore, we reflect on the potential therapeutic use of cell-type specific stimulation of PV INs within active networks and on the transplantation of PV INs precursors in the treatment of epilepsy and its comorbidities.
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Affiliation(s)
- X Jiang
- Université de Montréal, Montréal, QC, Canada; CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - M Lachance
- CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - E Rossignol
- Université de Montréal, Montréal, QC, Canada; CHU Ste-Justine Research Center, Montréal, QC, Canada.
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Wang X, Song X, Wu L, Nadler JV, Zhan RZ. Persistent Hyperactivity of Hippocampal Dentate Interneurons After a Silent Period in the Rat Pilocarpine Model of Epilepsy. Front Cell Neurosci 2016; 10:94. [PMID: 27092056 PMCID: PMC4824773 DOI: 10.3389/fncel.2016.00094] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 03/24/2016] [Indexed: 12/15/2022] Open
Abstract
Profile of GABAergic interneuron activity after pilocarpine-induced status epilepticus (SE) was examined in the rat hippocampal dentate gyrus by analyzing immediate early gene expression and recording spontaneous firing at near resting membrane potential (REM). SE for exact 2 h or more than 2 h was induced in the male Sprague-Dawley rats by an intraperitoneal injection of pilocarpine. Expression of immediate early genes (IEGs) was examined at 1 h, 1 week, 2 weeks or more than 10 weeks after SE. For animals to be examined at 1 h after SE, SE lasted for exact 2 h was terminated by an intraperitoneal injection of diazepam. Spontaneous firing at near the REM was recorded in interneurons located along the border between the granule cell layer and the hilus more than 10 weeks after SE. Results showed that both c-fos and activity-regulated cytoskeleton associated protein (Arc) in hilar GABAergic interneurons were up-regulated after SE in a biphasic manner; they were increased at 1 h and more than 2 weeks, but not at 1 week after SE. Ten weeks after SE, nearly 60% of hilar GABAergic cells expressed c-fos. With the exception of calretinin (CR)-positive cells, percentages of hilar neuronal nitric oxide synthase (nNOS)-, neuropeptide Y (NPY)-, parvalbumin (PV)-, and somatostatin (SOM)-positive cells with c-fos expression are significantly higher than those of controls more than 10 weeks after SE. Without the REM to be more depolarizing and changed threshold potential level in SE-induced rats, cell-attached recording revealed that nearly 90% of hilar interneurons fired spontaneously at near the REM while only 22% of the same cell population did so in the controls. In conclusion, pilocarpine-induced SE eventually leads to a state in which surviving dentate GABAergic interneurons become hyperactive with a subtype-dependent manner; this implies that a fragile balance between excitation and inhibition exists in the dentate gyrus and in addition, the activity-dependent up-regulation of IEGs may underlie plastic changes seen in some types of GABAergic cells in the pilocarpine model of epilepsy.
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Affiliation(s)
- Xiaochen Wang
- Department of Physiology, Shandong University School of Medicine Jinan, China
| | - Xinyu Song
- Department of Respiratory Medicine, Affiliated Hospital of Binzhou Medical University Binzhou, Shandong, China
| | - Lin Wu
- Department of Physiology, Shandong University School of Medicine Jinan, China
| | - J Victor Nadler
- Department of Pharmacology and Cancer Biology, Duke University Medical Center Durham, NC, USA
| | - Ren-Zhi Zhan
- Department of Physiology, Shandong University School of Medicine Jinan, China
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Brain State Is a Major Factor in Preseizure Hippocampal Network Activity and Influences Success of Seizure Intervention. J Neurosci 2016; 35:15635-48. [PMID: 26609157 DOI: 10.1523/jneurosci.5112-14.2015] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
UNLABELLED Neural dynamics preceding seizures are of interest because they may shed light on mechanisms of seizure generation and could be predictive. In healthy animals, hippocampal network activity is shaped by behavioral brain state and, in epilepsy, seizures selectively emerge during specific brain states. To determine the degree to which changes in network dynamics before seizure are pathological or reflect ongoing fluctuations in brain state, dorsal hippocampal neurons were recorded during spontaneous seizures in a rat model of temporal lobe epilepsy. Seizures emerged from all brain states, but with a greater likelihood after REM sleep, potentially due to an observed increase in baseline excitability during periods of REM compared with other brains states also characterized by sustained theta oscillations. When comparing the firing patterns of the same neurons across brain states associated with and without seizures, activity dynamics before seizures followed patterns typical of the ongoing brain state, or brain state transitions, and did not differ until the onset of the electrographic seizure. Next, we tested whether disparate activity patterns during distinct brain states would influence the effectiveness of optogenetic curtailment of hippocampal seizures in a mouse model of temporal lobe epilepsy. Optogenetic curtailment was significantly more effective for seizures preceded by non-theta states compared with seizures that emerged from theta states. Our results indicate that consideration of behavioral brain state preceding a seizure is important for the appropriate interpretation of network dynamics leading up to a seizure and for designing effective seizure intervention. SIGNIFICANCE STATEMENT Hippocampal single-unit activity is strongly shaped by behavioral brain state, yet this relationship has been largely ignored when studying activity dynamics before spontaneous seizures in medial temporal lobe epilepsy. In light of the increased attention on using single-unit activity for the prediction of seizure onset and closed-loop seizure intervention, we show a need for monitoring brain state to interpret correctly whether changes in neural activity before seizure onset is pathological or normal. Moreover, we also find that the brain state preceding a seizure determines the success of therapeutic interventions to curtail seizure duration. Together, these findings suggest that seizure prediction and intervention will be more successful if tailored for the specific brain states from which seizures emerge.
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Nakajima K, Hirai S, Morio T, Okado H. Benzodiazepines induce sequelae in immature mice with inflammation-induced status epilepticus. Epilepsy Behav 2015; 52:180-6. [PMID: 26439655 DOI: 10.1016/j.yebeh.2015.08.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/09/2015] [Accepted: 08/10/2015] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Since benzodiazepines (BZPs) became clinically available for the treatment of status epilepticus (SE) in children, the incidence of neurological sequelae has increased. However, the cause-effect relationship is poorly understood. In this paper, we examined the effect of BZPs on an inflammation-induced SE (iSE) animal model. METHOD Inflammation was induced by injecting poly(I:C) (pIC 10 mg/kg, postnatal day 12-14), seizure was induced by injecting pilocarpine hydrochloride (PILO 200 mg/kg, postnatal day 15) into C57BL/6J mice, and the pIC+PILO mice were used as the iSE model (miSE). The GABA-A receptor agonist midazolam (MDL 0.5 mg/kg) was used to inhibit seizures. Sequelae were evaluated by performing behavior and immunohistochemical analyses in the chronic phase. RESULT The exploratory activity of mice in the miSE plus MDL group increased significantly, indicating that hyperactivity was newly induced by MDL in miSE mice. The contextual fear memory of the miSE mice was also significantly increased and that of miSE treated with MDL returned to the normal level. The parvalbumin-positive GABA neurons were decreased in number by pIC+PILO which was rescued by MDL. Apoptosis marker ssDNA-positive cells were increased by pIC+PILO which could not be rescued by MDL. Therefore, we propose that BZP-dependent therapy for SE needs to be rethought from the perspective of using other treatment approaches.
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Affiliation(s)
- Keisuke Nakajima
- Department of Brain Development and Neural Regeneration, Neural Development Project, Tokyo Metropolitan Institute of Medical Science, Japan; Department of Pediatrics and Developmental Biology, Tokyo Medical and Dental University, Japan
| | - Shinobu Hirai
- Department of Brain Development and Neural Regeneration, Neural Development Project, Tokyo Metropolitan Institute of Medical Science, Japan
| | - Tomohiro Morio
- Department of Pediatrics and Developmental Biology, Tokyo Medical and Dental University, Japan
| | - Haruo Okado
- Department of Brain Development and Neural Regeneration, Neural Development Project, Tokyo Metropolitan Institute of Medical Science, Japan.
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Meijer HGE, Eissa TL, Kiewiet B, Neuman JF, Schevon CA, Emerson RG, Goodman RR, McKhann GM, Marcuccilli CJ, Tryba AK, Cowan JD, van Gils SA, van Drongelen W. Modeling focal epileptic activity in the Wilson-cowan model with depolarization block. JOURNAL OF MATHEMATICAL NEUROSCIENCE 2015; 5:7. [PMID: 25852982 PMCID: PMC4385301 DOI: 10.1186/s13408-015-0019-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 02/19/2015] [Indexed: 06/04/2023]
Abstract
UNLABELLED Measurements of neuronal signals during human seizure activity and evoked epileptic activity in experimental models suggest that, in these pathological states, the individual nerve cells experience an activity driven depolarization block, i.e. they saturate. We examined the effect of such a saturation in the Wilson-Cowan formalism by adapting the nonlinear activation function; we substituted the commonly applied sigmoid for a Gaussian function. We discuss experimental recordings during a seizure that support this substitution. Next we perform a bifurcation analysis on the Wilson-Cowan model with a Gaussian activation function. The main effect is an additional stable equilibrium with high excitatory and low inhibitory activity. Analysis of coupled local networks then shows that such high activity can stay localized or spread. Specifically, in a spatial continuum we show a wavefront with inhibition leading followed by excitatory activity. We relate our model simulations to observations of spreading activity during seizures. ELECTRONIC SUPPLEMENTARY MATERIAL The online version of this article (doi:10.1186/s13408-015-0019-4) contains supplementary material 1.
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Affiliation(s)
- Hil G. E. Meijer
- />Department of Applied Mathematics, MIRA Institute for Biomedical Engineering and Technical Medicine, University of Twente, Postbus 217, Enschede, 7500AE The Netherlands
| | - Tahra L. Eissa
- />Department of Pediatrics, University of Chicago, KCBD 900 East 57th Street, Chicago, IL 60637 USA
| | - Bert Kiewiet
- />Department of Applied Mathematics, MIRA Institute for Biomedical Engineering and Technical Medicine, University of Twente, Postbus 217, Enschede, 7500AE The Netherlands
| | - Jeremy F. Neuman
- />Department of Physics, University of Chicago, 5720 South Ellis Avenue, Chicago, IL 60637 USA
| | - Catherine A. Schevon
- />Department of Neurology, Columbia University, 710 West 168th Street, New York, NY 10032 USA
| | - Ronald G. Emerson
- />Department of Neurology, Columbia University, 710 West 168th Street, New York, NY 10032 USA
- />Department of Neurological Surgery, Columbia University, 710 West 168th Street, New York, NY 10032 USA
| | - Robert R. Goodman
- />Department of Neurological Surgery, Columbia University, 710 West 168th Street, New York, NY 10032 USA
| | - Guy M. McKhann
- />Department of Neurological Surgery, Columbia University, 710 West 168th Street, New York, NY 10032 USA
| | - Charles J. Marcuccilli
- />Department of Pediatrics, University of Chicago, KCBD 900 East 57th Street, Chicago, IL 60637 USA
| | - Andrew K. Tryba
- />Department of Pediatrics, University of Chicago, KCBD 900 East 57th Street, Chicago, IL 60637 USA
| | - Jack D. Cowan
- />Department of Mathematics, University of Chicago, 5734 South University Avenue, Chicago, IL 60637 USA
| | - Stephan A. van Gils
- />Department of Applied Mathematics, MIRA Institute for Biomedical Engineering and Technical Medicine, University of Twente, Postbus 217, Enschede, 7500AE The Netherlands
| | - Wim van Drongelen
- />Department of Pediatrics, University of Chicago, KCBD 900 East 57th Street, Chicago, IL 60637 USA
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