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Shah PT, Valiante TA, Packer AM. Highly local activation of inhibition at the seizure wavefront in vivo. Cell Rep 2024; 43:114189. [PMID: 38703365 DOI: 10.1016/j.celrep.2024.114189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 12/22/2023] [Accepted: 04/17/2024] [Indexed: 05/06/2024] Open
Abstract
The propagation of a seizure wavefront in the cortex divides an intensely firing seizure core from a low-firing seizure penumbra. Seizure propagation is currently thought to generate strong activation of inhibition in the seizure penumbra that leads to its decreased neuronal firing. However, the direct measurement of neuronal excitability during seizures has been difficult to perform in vivo. We used simultaneous optogenetics and calcium imaging (all-optical interrogation) to characterize real-time neuronal excitability in an acute mouse model of seizure propagation. We find that single-neuron excitability is decreased in close proximity to the seizure wavefront but becomes increased distal to the seizure wavefront. This suggests that inhibitory neurons of the seizure wavefront create a proximal circumference of hypoexcitability but do not influence neuronal excitability in the penumbra.
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Affiliation(s)
- Prajay T Shah
- Krembil Brain Institute, University Health Network, Toronto, ON, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Taufik A Valiante
- Krembil Brain Institute, University Health Network, Toronto, ON, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada; Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada; Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Adam M Packer
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, UK.
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2
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Xu P, Swain S, Novorolsky RJ, Garcia E, Huang Z, Snutch TP, Wilson JJ, Robertson GS, Renden RB. The mitochondrial calcium uniporter inhibitor Ru265 increases neuronal excitability and reduces neurotransmission via off-target effects. Br J Pharmacol 2024. [PMID: 38779706 DOI: 10.1111/bph.16425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND AND PURPOSE Excitotoxicity due to mitochondrial calcium (Ca2+) overloading can trigger neuronal cell death in a variety of pathologies. Inhibiting the mitochondrial calcium uniporter (MCU) has been proposed as a therapeutic avenue to prevent calcium overloading. Ru265 (ClRu(NH3)4(μ-N)Ru(NH3)4Cl]Cl3) is a cell-permeable inhibitor of the mitochondrial calcium uniporter (MCU) with nanomolar affinity. Ru265 reduces sensorimotor deficits and neuronal death in models of ischemic stroke. However, the therapeutic use of Ru265 is limited by the induction of seizure-like behaviours. EXPERIMENTAL APPROACH We examined the effect of Ru265 on synaptic and neuronal function in acute brain slices and hippocampal neuron cultures derived from mice, in control and where MCU expression was genetically abrogated. KEY RESULTS Ru265 decreased evoked responses from calyx terminals and induced spontaneous action potential firing of both the terminal and postsynaptic principal cell. Recordings of presynaptic Ca2+ currents suggested that Ru265 blocks the P/Q type channel, confirmed by the inhibition of currents in cells exogenously expressing the P/Q type channel. Measurements of presynaptic K+ currents further revealed that Ru265 blocked a KCNQ current, leading to increased membrane excitability, underlying spontaneous spiking. Ca2+ imaging of hippocampal neurons showed that Ru265 increased synchronized, high-amplitude events, recapitulating seizure-like activity seen in vivo. Importantly, MCU ablation did not suppress Ru265-induced increases in neuronal activity and seizures. CONCLUSIONS AND IMPLICATIONS Our findings provide a mechanistic explanation for the pro-convulsant effects of Ru265 and suggest counter screening assays based on the measurement of P/Q and KCNQ channel currents to identify safe MCU inhibitors.
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Affiliation(s)
- Peng Xu
- Department of Physiology and Cell Biology, University of Nevada, Reno, Reno, Nevada, USA
| | - Sarpras Swain
- Department of Physiology and Cell Biology, University of Nevada, Reno, Reno, Nevada, USA
| | - Robyn J Novorolsky
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Esperanza Garcia
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health University of British Columbia, Vancouver, British Columbia, Canada
| | - Zhouyang Huang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA
| | - Terrance P Snutch
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health University of British Columbia, Vancouver, British Columbia, Canada
| | - Justin J Wilson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA
| | - George S Robertson
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Robert B Renden
- Department of Physiology and Cell Biology, University of Nevada, Reno, Reno, Nevada, USA
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Leitch B. Parvalbumin Interneuron Dysfunction in Neurological Disorders: Focus on Epilepsy and Alzheimer's Disease. Int J Mol Sci 2024; 25:5549. [PMID: 38791587 PMCID: PMC11122153 DOI: 10.3390/ijms25105549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/11/2024] [Accepted: 05/16/2024] [Indexed: 05/26/2024] Open
Abstract
Parvalbumin expressing (PV+) GABAergic interneurons are fast spiking neurons that provide powerful but relatively short-lived inhibition to principal excitatory cells in the brain. They play a vital role in feedforward and feedback synaptic inhibition, preventing run away excitation in neural networks. Hence, their dysfunction can lead to hyperexcitability and increased susceptibility to seizures. PV+ interneurons are also key players in generating gamma oscillations, which are synchronized neural oscillations associated with various cognitive functions. PV+ interneuron are particularly vulnerable to aging and their degeneration has been associated with cognitive decline and memory impairment in dementia and Alzheimer's disease (AD). Overall, dysfunction of PV+ interneurons disrupts the normal excitatory/inhibitory balance within specific neurocircuits in the brain and thus has been linked to a wide range of neurodevelopmental and neuropsychiatric disorders. This review focuses on the role of dysfunctional PV+ inhibitory interneurons in the generation of epileptic seizures and cognitive impairment and their potential as targets in the design of future therapeutic strategies to treat these disorders. Recent research using cutting-edge optogenetic and chemogenetic technologies has demonstrated that they can be selectively manipulated to control seizures and restore the balance of neural activity in the brains of animal models. This suggests that PV+ interneurons could be important targets in developing future treatments for patients with epilepsy and comorbid disorders, such as AD, where seizures and cognitive decline are directly linked to specific PV+ interneuron deficits.
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Affiliation(s)
- Beulah Leitch
- Department of Anatomy, School of Biomedical Sciences, Brain Health Research Centre, University of Otago, Dunedin 9016, New Zealand
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4
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Vaughan AJ, McMeekin LJ, Hine K, Stubbs IW, Codadu NK, Cockell S, Hill JT, Cowell R, Trevelyan AJ, Parrish RR. RNA Sequencing Demonstrates Ex Vivo Neocortical Transcriptomic Changes Induced by Epileptiform Activity in Male and Female Mice. eNeuro 2024; 11:ENEURO.0520-23.2024. [PMID: 38664009 PMCID: PMC11129778 DOI: 10.1523/eneuro.0520-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 04/13/2024] [Accepted: 04/18/2024] [Indexed: 05/26/2024] Open
Abstract
Seizures are generally associated with epilepsy but may also be a symptom of many other neurological conditions. A hallmark of a seizure is the intensity of the local neuronal activation, which can drive large-scale gene transcription changes. Such changes in the transcriptional profile likely alter neuronal function, thereby contributing to the pathological process. Therefore, there is a strong clinical imperative to characterize how gene expression is changed by seizure activity. To this end, we developed a simplified ex vivo technique for studying seizure-induced transcriptional changes. We compared the RNA sequencing profile in mouse neocortical tissue with up to 3 h of epileptiform activity induced by 4-aminopyridine (4AP) relative to control brain slices not exposed to the drug. We identified over 100 genes with significantly altered expression after 4AP treatment, including multiple genes involved in MAPK, TNF, and neuroinflammatory signaling pathways, all of which have been linked to epilepsy previously. Notably, the patterns in male and female brain slices were almost identical. Various immediate early genes were among those showing the largest upregulation. The set of down-regulated genes included ones that might be expected either to increase or to decrease neuronal excitability. In summary, we found the seizure-induced transcriptional profile complex, but the changes aligned well with an analysis of published epilepsy-associated genes. We discuss how simple models may provide new angles for investigating seizure-induced transcriptional changes.
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Affiliation(s)
- Alec J Vaughan
- Department of Cell Biology and Physiology, Brigham Young University, Provo, Utah 84602
| | - Laura J McMeekin
- Department of Neurology, University of Alabama, Birmingham, Birmingham, Alabama 35233
| | - Kutter Hine
- Department of Cell Biology and Physiology, Brigham Young University, Provo, Utah 84602
| | - Isaac W Stubbs
- Department of Cell Biology and Physiology, Brigham Young University, Provo, Utah 84602
| | - Neela K Codadu
- Newcastle University Biosciences Institute, Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Simon Cockell
- School of Biomedical, Nutritional and Sports Science, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Jonathon T Hill
- Department of Cell Biology and Physiology, Brigham Young University, Provo, Utah 84602
| | - Rita Cowell
- Department of Neurology, University of Alabama, Birmingham, Birmingham, Alabama 35233
| | - Andrew J Trevelyan
- Newcastle University Biosciences Institute, Medical School, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - R Ryley Parrish
- Department of Cell Biology and Physiology, Brigham Young University, Provo, Utah 84602
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5
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Ma Z, Xu Y, Baier G, Liu Y, Li B, Zhang L. Dynamical modulation of hypersynchronous seizure onset with transcranial magneto-acoustic stimulation in a hippocampal computational model. CHAOS (WOODBURY, N.Y.) 2024; 34:043107. [PMID: 38558041 DOI: 10.1063/5.0181510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 03/09/2024] [Indexed: 04/04/2024]
Abstract
Hypersynchronous (HYP) seizure onset is one of the frequently observed seizure-onset patterns in temporal lobe epileptic animals and patients, often accompanied by hippocampal sclerosis. However, the exact mechanisms and ion dynamics of the transition to HYP seizures remain unclear. Transcranial magneto-acoustic stimulation (TMAS) has recently been proposed as a novel non-invasive brain therapy method to modulate neurological disorders. Therefore, we propose a biophysical computational hippocampal network model to explore the evolution of HYP seizure caused by changes in crucial physiological parameters and design an effective TMAS strategy to modulate HYP seizure onset. We find that the cooperative effects of abnormal glial uptake strength of potassium and excessive bath potassium concentration could produce multiple discharge patterns and result in transitions from the normal state to the HYP seizure state and ultimately to the depolarization block state. Moreover, we find that the pyramidal neuron and the PV+ interneuron in HYP seizure-onset state exhibit saddle-node-on-invariant-circle/saddle homoclinic (SH) and saddle-node/SH at onset/offset bifurcation pairs, respectively. Furthermore, the response of neuronal activities to TMAS of different ultrasonic waveforms revealed that lower sine wave stimulation can increase the latency of HYP seizures and even completely suppress seizures. More importantly, we propose an ultrasonic parameter area that not only effectively regulates epileptic rhythms but also is within the safety limits of ultrasound neuromodulation therapy. Our results may offer a more comprehensive understanding of the mechanisms of HYP seizure and provide a theoretical basis for the application of TMAS in treating specific types of seizures.
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Affiliation(s)
- Zhiyuan Ma
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing 100124, China
| | - Yuejuan Xu
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing 100124, China
| | - Gerold Baier
- Cell and Developmental Biology, Faculty of Life Sciences, University College London, London WC1E 6BT, United Kingdom
| | - Youjun Liu
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing 100124, China
| | - Bao Li
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing 100124, China
| | - Liyuan Zhang
- Department of Biomedical Engineering, College of Chemistry and Life Science, Beijing University of Technology, Beijing 100124, China
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Miralles RM, Boscia AR, Kittur S, Vundela SR, Wengert ER, Patel MK. Parvalbumin Interneuron Impairment Leads to Synaptic Transmission Deficits and Seizures in SCN8A Epileptic Encephalopathy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.09.579511. [PMID: 38464208 PMCID: PMC10925130 DOI: 10.1101/2024.02.09.579511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
SCN8A epileptic encephalopathy (EE) is a severe epilepsy syndrome resulting from de novo mutations in the voltage-gated sodium channel Na v 1.6, encoded by the gene SCN8A . Na v 1.6 is expressed in both excitatory and inhibitory neurons, yet previous studies have primarily focused on the impact SCN8A mutations have on excitatory neuron function, with limited studies on the importance of inhibitory interneurons to seizure onset and progression. Inhibitory interneurons are critical in balancing network excitability and are known to contribute to the pathophysiology of other epilepsies. Parvalbumin (PV) interneurons are the most prominent inhibitory neuron subtype in the brain, making up about 40% of inhibitory interneurons. Notably, PV interneurons express high levels of Na v 1.6. To assess the role of PV interneurons within SCN8A EE, we used two mouse models harboring patient-derived SCN8A gain-of-function mutations, Scn8a D/+ , where the SCN8A mutation N1768D is expressed globally, and Scn8a W/+ -PV, where the SCN8A mutation R1872W is selectively expressed in PV interneurons. Expression of the R1872W SCN8A mutation selectively in PV interneurons led to the development of spontaneous seizures in Scn8a W/+ -PV mice and seizure-induced death, decreasing survival compared to wild-type. Electrophysiology studies showed that PV interneurons in Scn8a D/+ and Scn8a W/+ -PV mice were susceptible to depolarization block, a state of action potential failure. Scn8a D/+ and Scn8a W/+ -PV interneurons also exhibited increased persistent sodium current, a hallmark of SCN8A gain-of-function mutations that contributes to depolarization block. Evaluation of synaptic connections between PV interneurons and pyramidal cells showed an increase in synaptic transmission failure at high frequencies (80-120Hz) as well as an increase in synaptic latency in Scn8a D/+ and Scn8a W/+ -PV interneurons. These data indicate a distinct impairment of synaptic transmission in SCN8A EE, potentially decreasing overall cortical network inhibition. Together, our novel findings indicate that failure of PV interneuron spiking via depolarization block along with frequency-dependent inhibitory synaptic impairment likely elicits an overall reduction in the inhibitory drive in SCN8A EE, leading to unchecked excitation and ultimately resulting in seizures and seizure-induced death.
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7
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Meneghetti N, Vannini E, Mazzoni A. Rodents' visual gamma as a biomarker of pathological neural conditions. J Physiol 2024; 602:1017-1048. [PMID: 38372352 DOI: 10.1113/jp283858] [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: 12/13/2022] [Accepted: 01/23/2024] [Indexed: 02/20/2024] Open
Abstract
Neural gamma oscillations (indicatively 30-100 Hz) are ubiquitous: they are associated with a broad range of functions in multiple cortical areas and across many animal species. Experimental and computational works established gamma rhythms as a global emergent property of neuronal networks generated by the balanced and coordinated interaction of excitation and inhibition. Coherently, gamma activity is strongly influenced by the alterations of synaptic dynamics which are often associated with pathological neural dysfunctions. We argue therefore that these oscillations are an optimal biomarker for probing the mechanism of cortical dysfunctions. Gamma oscillations are also highly sensitive to external stimuli in sensory cortices, especially the primary visual cortex (V1), where the stimulus dependence of gamma oscillations has been thoroughly investigated. Gamma manipulation by visual stimuli tuning is particularly easy in rodents, which have become a standard animal model for investigating the effects of network alterations on gamma oscillations. Overall, gamma in the rodents' visual cortex offers an accessible probe on dysfunctional information processing in pathological conditions. Beyond vision-related dysfunctions, alterations of gamma oscillations in rodents were indeed also reported in neural deficits such as migraine, epilepsy and neurodegenerative or neuropsychiatric conditions such as Alzheimer's, schizophrenia and autism spectrum disorders. Altogether, the connections between visual cortical gamma activity and physio-pathological conditions in rodent models underscore the potential of gamma oscillations as markers of neuronal (dys)functioning.
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Affiliation(s)
- Nicolò Meneghetti
- The Biorobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
- Department of Excellence for Robotics and AI, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Eleonora Vannini
- Neuroscience Institute, National Research Council (CNR), Pisa, Italy
| | - Alberto Mazzoni
- The Biorobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
- Department of Excellence for Robotics and AI, Scuola Superiore Sant'Anna, Pisa, Italy
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8
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Shimoda Y, Leite M, Graham RT, Marvin JS, Hasseman J, Kolb I, Looger LL, Magloire V, Kullmann DM. Extracellular glutamate and GABA transients at the transition from interictal spiking to seizures. Brain 2024; 147:1011-1024. [PMID: 37787057 PMCID: PMC10907087 DOI: 10.1093/brain/awad336] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 08/29/2023] [Accepted: 09/16/2023] [Indexed: 10/04/2023] Open
Abstract
Focal epilepsy is associated with intermittent brief population discharges (interictal spikes), which resemble sentinel spikes that often occur at the onset of seizures. Why interictal spikes self-terminate whilst seizures persist and propagate is incompletely understood. We used fluorescent glutamate and GABA sensors in an awake rodent model of neocortical seizures to resolve the spatiotemporal evolution of both neurotransmitters in the extracellular space. Interictal spikes were accompanied by brief glutamate transients which were maximal at the initiation site and rapidly propagated centrifugally. GABA transients lasted longer than glutamate transients and were maximal ∼1.5 mm from the focus where they propagated centripetally. Prior to seizure initiation GABA transients were attenuated, whilst glutamate transients increased, consistent with a progressive failure of local inhibitory restraint. As seizures increased in frequency, there was a gradual increase in the spatial extent of spike-associated glutamate transients associated with interictal spikes. Neurotransmitter imaging thus reveals a progressive collapse of an annulus of feed-forward GABA release, allowing seizures to escape from local inhibitory restraint.
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Affiliation(s)
- Yoshiteru Shimoda
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Marco Leite
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Robert T Graham
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Jonathan S Marvin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Jeremy Hasseman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Ilya Kolb
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Loren L Looger
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Vincent Magloire
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Dimitri M Kullmann
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
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Yu H, Shao M, Luo X, Pang C, So KF, Yu J, Zhang L. Treadmill exercise improves hippocampal neural plasticity and relieves cognitive deficits in a mouse model of epilepsy. Neural Regen Res 2024; 19:657-662. [PMID: 37721298 PMCID: PMC10581559 DOI: 10.4103/1673-5374.377771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 04/18/2023] [Accepted: 05/25/2023] [Indexed: 09/19/2023] Open
Abstract
Epilepsy frequently leads to cognitive dysfunction and approaches to treatment remain limited. Although regular exercise effectively improves learning and memory functions across multiple neurological diseases, its application in patients with epilepsy remains controversial. Here, we adopted a 14-day treadmill-exercise paradigm in a pilocarpine injection-induced mouse model of epilepsy. Cognitive assays confirmed the improvement of object and spatial memory after endurance training, and electrophysiological studies revealed the maintenance of hippocampal plasticity as a result of physical exercise. Investigations of the mechanisms underlying this effect revealed that exercise protected parvalbumin interneurons, probably via the suppression of neuroinflammation and improved integrity of blood-brain barrier. In summary, this work identified a previously unknown mechanism through which exercise improves cognitive rehabilitation in epilepsy.
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Affiliation(s)
- Hang Yu
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
| | - Mingting Shao
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
| | - Xi Luo
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
| | - Chaoqin Pang
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
| | - Kwok-Fai So
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
- State Key Laboratory of Brain and Cognitive Science, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
- Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, Shandong Province, China
| | - Jiandong Yu
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
- Department of Neurosurgery, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Shandong Province, China
| | - Li Zhang
- Key Laboratory of CNS Regeneration (Ministry of Education), Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, Guangdong Province, China
- Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, Shandong Province, China
- School of Psychology, Shanghai University of Sport, Shanghai, China
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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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11
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Wenzel M, Huberfeld G, Grayden DB, de Curtis M, Trevelyan AJ. A debate on the neuronal origin of focal seizures. Epilepsia 2023; 64 Suppl 3:S37-S48. [PMID: 37183507 DOI: 10.1111/epi.17650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/26/2023] [Accepted: 05/12/2023] [Indexed: 05/16/2023]
Abstract
A critical question regarding how focal seizures start is whether we can identify particular cell classes that drive the pathological process. This was the topic for debate at the recent International Conference for Technology and Analysis of Seizures (ICTALS) meeting (July 2022, Bern, CH) that we summarize here. The debate has been fueled in recent times by the introduction of powerful new ways to manipulate subpopulations of cells in relative isolation, mostly using optogenetics. The motivation for resolving the debate is to identify novel targets for therapeutic interventions through a deeper understanding of the etiology of seizures.
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Affiliation(s)
- Michael Wenzel
- Department of Epileptology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Gilles Huberfeld
- Neurology Department, Hopital Fondation Adolphe de Rothschild, Paris, France
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France
| | - David B Grayden
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Medicine, St Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
- Graeme Clark Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | - Marco de Curtis
- Epilepsy Unit, Fondazione I.R.C.C.S., Istituto Neurologico Carlo Besta, Milan, Italy
| | - Andrew J Trevelyan
- Newcastle University Biosciences Institute, Medical School, Framlington Place, Newcastle upon Tyne, UK
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12
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Lemaire L, Desroches M, Krupa M, Mantegazza M. Idealized multiple-timescale model of cortical spreading depolarization initiation and pre-epileptic hyperexcitability caused by Na V1.1/SCN1A mutations. J Math Biol 2023; 86:92. [PMID: 37171678 DOI: 10.1007/s00285-023-01917-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 01/30/2023] [Accepted: 03/28/2023] [Indexed: 05/13/2023]
Abstract
NaV1.1 (SCN1A) is a voltage-gated sodium channel mainly expressed in GABAergic neurons. Loss of function mutations of NaV1.1 lead to epileptic disorders, while gain of function mutations cause a migraine in which cortical spreading depolarizations (CSDs) are involved. It is still debated how these opposite effects initiate two different manifestations of neuronal hyperactivity: epileptic seizures and CSD. To investigate this question, we previously built a conductance-based model of two neurons (GABAergic and pyramidal), with dynamic ion concentrations (Lemaire et al. in PLoS Comput Biol 17(7):e1009239, 2021. https://doi.org/10.1371/journal.pcbi.1009239 ). When implementing either NaV1.1 migraine or epileptogenic mutations, ion concentration modifications acted as slow processes driving the system to the corresponding pathological firing regime. However, the large dimensionality of the model complicated the exploitation of its implicit multi-timescale structure. Here, we substantially simplify our biophysical model to a minimal version more suitable for bifurcation analysis. The explicit timescale separation allows us to apply slow-fast theory, where slow variables are treated as parameters in the fast singular limit. In this setting, we reproduce both pathological transitions as dynamic bifurcations in the full system. In the epilepsy condition, we shift the spike-terminating bifurcation to lower inputs for the GABAergic neuron, to model an increased susceptibility to depolarization block. The resulting failure of synaptic inhibition triggers hyperactivity of the pyramidal neuron. In the migraine scenario, spiking-induced release of potassium leads to the abrupt increase of the extracellular potassium concentration. This causes a dynamic spike-terminating bifurcation of both neurons, which we interpret as CSD initiation.
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Affiliation(s)
- Louisiane Lemaire
- Inria at Université Côte d'Azur, MathNeuro Project-Team, Valbonne-Sophia Antipolis, France.
- Institute for Theoretical Biology, Humboldt-University of Berlin, Berlin, Germany.
- Bernstein Center for Computational Neuroscience, Berlin, Germany.
| | - Mathieu Desroches
- Inria at Université Côte d'Azur, MathNeuro Project-Team, Valbonne-Sophia Antipolis, France
| | - Martin Krupa
- Inria at Université Côte d'Azur, MathNeuro Project-Team, Valbonne-Sophia Antipolis, France
- Laboratoire Jean-Alexandre Dieudonné, Université Côte d'Azur, Nice, France
| | - Massimo Mantegazza
- Institute of Molecular and Cellular Pharmacology (IPMC), Université Côte d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- INSERM, Valbonne-Sophia Antipolis, France
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13
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Koessler L, Louviot S, Dmochowski J, Vignal JP, Jonas J, Colnat-Coulbois S, Tyvaert L, Maillard L. Transcranial direct current stimulation reduces intracerebrally-recorded epileptic seizures and behavioral disturbances. Brain Stimul 2023; 16:667-669. [PMID: 37015316 DOI: 10.1016/j.brs.2023.03.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 03/31/2023] [Indexed: 04/06/2023] Open
Affiliation(s)
| | - Samuel Louviot
- Université de Lorraine, CNRS, CRAN, UMR, 7039, Nancy, France
| | - Jacek Dmochowski
- Department of Biomedical Engineering, City College of New York, New York City, United States
| | - Jean-Pierre Vignal
- Université de Lorraine, CNRS, CRAN, UMR, 7039, Nancy, France; Centre Hospitalier Universitaire de Nancy, Service de Neurologie, Nancy, 54000, France
| | - Jacques Jonas
- Université de Lorraine, CNRS, CRAN, UMR, 7039, Nancy, France; Centre Hospitalier Universitaire de Nancy, Service de Neurologie, Nancy, 54000, France
| | - Sophie Colnat-Coulbois
- Université de Lorraine, CNRS, CRAN, UMR 7039, Nancy, France; Centre Hospitalier Universitaire de Nancy, Service de Neurochirurgie, Nancy, 54000, France
| | - Louise Tyvaert
- Université de Lorraine, CNRS, CRAN, UMR, 7039, Nancy, France; Centre Hospitalier Universitaire de Nancy, Service de Neurologie, Nancy, 54000, France
| | - Louis Maillard
- Université de Lorraine, CNRS, CRAN, UMR, 7039, Nancy, France; Centre Hospitalier Universitaire de Nancy, Service de Neurologie, Nancy, 54000, France
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14
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Vasilopoulos N, Kaplanian A, Vinos M, Katsaiti Y, Christodoulou O, Denaxa M, Skaliora I. The role of selective SATB1 deletion in somatostatin expressing interneurons on endogenous network activity and the transition to epilepsy. J Neurosci Res 2023; 101:424-447. [PMID: 36541427 DOI: 10.1002/jnr.25156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 10/24/2022] [Accepted: 12/03/2022] [Indexed: 12/24/2022]
Abstract
Somatostatin (SST) expressing interneurons are the second most abundant group of inhibitory neurons in the neocortex. They mainly target the apical dendrites of excitatory pyramidal cells and are implicated in feedforward and feedback inhibition. In the present study, we employ a conditional knockout mouse, in which the transcription factor Satb1 is selectively deleted in SST-expressing interneurons resulting to the reduction of their number across the somatosensory barrel field. Our goal was to investigate the effect of the reduced number of Satb1 mutant SST-interneurons on (i) the endogenous cortical network activity (spontaneously recurring Up/Down states), and (ii) the transition to epileptiform activity. By conducting LFP recordings in acute brain slices from young male and female mice, we demonstrate that mutant animals exhibit significant changes in network excitability, reflected in increased Up state occurrence, decreased Up state duration and higher levels of extracellular spiking activity. Epileptiform activity was induced through two distinct and widely used in vitro protocols: the low magnesium and the 4-Aminopyridine (4-AP) model. In the former, slices from mutant animals manifested shorter latency for the expression of stable seizure-like events. In contrast, when epilepsy was induced by 4-AP, no significant differences were reported. We conclude that normal SST-interneuron function has a significant role both in the regulation of the endogenous network activity, and in the transition to seizure-like discharges in a context-dependent manner.
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Affiliation(s)
- Nikos Vasilopoulos
- Centre for Basic Research, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece
| | - Ani Kaplanian
- Centre for Basic Research, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece
| | - Michael Vinos
- Centre for Basic Research, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece.,Department of History and Philosophy of Science, National and Kapodistrian University of Athens (NKUA), Athens, Greece
| | - Yolanda Katsaiti
- Biomedical Sciences Research Center "Alexander Fleming", Vari, Greece.,Department of Biology, National and Kapodistrian University of Athens (NKUA), Athens, Greece
| | - Ourania Christodoulou
- Biomedical Sciences Research Center "Alexander Fleming", Vari, Greece.,Department of Biology, University of Crete, Heraklion, Greece
| | - Myrto Denaxa
- Biomedical Sciences Research Center "Alexander Fleming", Vari, Greece
| | - Irini Skaliora
- Centre for Basic Research, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece.,Department of History and Philosophy of Science, National and Kapodistrian University of Athens (NKUA), Athens, Greece
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15
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Hameed MQ, Hodgson N, Lee HHC, Pascual-Leone A, MacMullin PC, Jannati A, Dhamne SC, Hensch TK, Rotenberg A. N-acetylcysteine treatment mitigates loss of cortical parvalbumin-positive interneuron and perineuronal net integrity resulting from persistent oxidative stress in a rat TBI model. Cereb Cortex 2023; 33:4070-4084. [PMID: 36130098 PMCID: PMC10068300 DOI: 10.1093/cercor/bhac327] [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: 05/26/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 11/12/2022] Open
Abstract
Traumatic brain injury (TBI) increases cerebral reactive oxygen species production, which leads to continuing secondary neuronal injury after the initial insult. Cortical parvalbumin-positive interneurons (PVIs; neurons responsible for maintaining cortical inhibitory tone) are particularly vulnerable to oxidative stress and are thus disproportionately affected by TBI. Systemic N-acetylcysteine (NAC) treatment may restore cerebral glutathione equilibrium, thus preventing post-traumatic cortical PVI loss. We therefore tested whether weeks-long post-traumatic NAC treatment mitigates cortical oxidative stress, and whether such treatment preserves PVI counts and related markers of PVI integrity and prevents pathologic electroencephalographic (EEG) changes, 3 and 6 weeks after fluid percussion injury in rats. We find that moderate TBI results in persistent oxidative stress for at least 6 weeks after injury and leads to the loss of PVIs and the perineuronal net (PNN) that surrounds them as well as of per-cell parvalbumin expression. Prolonged post-TBI NAC treatment normalizes the cortical redox state, mitigates PVI and PNN loss, and - in surviving PVIs - increases per-cell parvalbumin expression. NAC treatment also preserves normal spectral EEG measures after TBI. We cautiously conclude that weeks-long NAC treatment after TBI may be a practical and well-tolerated treatment strategy to preserve cortical inhibitory tone post-TBI.
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Affiliation(s)
- Mustafa Q Hameed
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Department of Neurosurgery, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Nathaniel Hodgson
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Henry H C Lee
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Andres Pascual-Leone
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Paul C MacMullin
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Ali Jannati
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Sameer C Dhamne
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Takao K Hensch
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Department of Molecular & Cellular Biology, Center for Brain Science, Harvard University, 52 Oxford Street, Cambridge, MA 02138, United States
| | - Alexander Rotenberg
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, 300 Longwood Avenue, Boston, MA 02115, United States
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16
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Scalmani P, Paterra R, Mantegazza M, Avoli M, de Curtis M. Involvement of GABAergic Interneuron Subtypes in 4-Aminopyridine-Induced Seizure-Like Events in Mouse Entorhinal Cortex in Vitro. J Neurosci 2023; 43:1987-2001. [PMID: 36810229 PMCID: PMC10027059 DOI: 10.1523/jneurosci.1190-22.2023] [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: 06/17/2022] [Revised: 12/30/2022] [Accepted: 01/05/2023] [Indexed: 02/23/2023] Open
Abstract
Single-unit recordings performed in temporal lobe epilepsy patients and in models of temporal lobe seizures have shown that interneurons are active at focal seizure onset. We performed simultaneous patch-clamp and field potential recordings in entorhinal cortex slices of GAD65 and GAD67 C57BL/6J male mice that express green fluorescent protein in GABAergic neurons to analyze the activity of specific interneuron (IN) subpopulations during acute seizure-like events (SLEs) induced by 4-aminopyridine (4-AP; 100 μm). IN subtypes were identified as parvalbuminergic (INPV, n = 17), cholecystokinergic (INCCK), n = 13], and somatostatinergic (INSOM, n = 15), according to neurophysiological features and single-cell digital PCR. INPV and INCCK discharged at the start of 4-AP-induced SLEs characterized by either low-voltage fast or hyper-synchronous onset pattern. In both SLE onset types, INSOM fired earliest before SLEs, followed by INPV and INCCK discharges. Pyramidal neurons became active with variable delays after SLE onset. Depolarizing block was observed in ∼50% of cells in each INs subgroup, and it was longer in IN (∼4 s) than in pyramidal neurons (<1 s). As SLE evolved, all IN subtypes generated action potential bursts synchronous with the field potential events leading to SLE termination. High-frequency firing throughout the SLE occurred in one-third of INPV and INSOM We conclude that entorhinal cortex INs are very active at the onset and during the progression of SLEs induced by 4-AP. These results support earlier in vivo and in vivo evidence and suggest that INs have a preferential role in focal seizure initiation and development.SIGNIFICANCE STATEMENT Focal seizures are believed to result from enhanced excitation. Nevertheless, we and others demonstrated that cortical GABAergic networks may initiate focal seizures. Here, we analyzed for the first time the role of different IN subtypes in seizures generated by 4-aminopyridine in the mouse entorhinal cortex slices. We found that in this in vitro focal seizure model, all IN types contribute to seizure initiation and that INs precede firing of principal cells. This evidence is in agreement with the active role of GABAergic networks in seizure generation.
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Affiliation(s)
| | - Rosina Paterra
- Neuro-Oncology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano 20133, Italy
| | - Massimo Mantegazza
- Université Côte d'Azur, 06560 Valbonne-Sophia Antipolis, France
- Institute of Molecular and Cellular Pharmacology, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7275, Laboratoire d'Excellence/Canaux Ioniques d'Intérêt Thérapeutique, 06650 Valbonne-Sophia Antipolis, France
- Institut National de la Santé et de la Recherche Médicale, 06650 Valbonne-Sophia Antipolis, France
| | - Massimo Avoli
- Montreal Neurological Institute-Hospital, McGill University, Montreal, Quebec H3A 2B4, Canada
- Departments of Neurology and Neurosurgery and Physiology, McGill University, Montreal, Quebec H3A 2B4, Canada
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17
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Alamoudi OA, Ilyas A, Pati S, Iasemidis L. Interictal localization of the epileptogenic zone: Utilizing the observed resonance behavior in the spectral band of surrounding inhibition. Front Neurosci 2022; 16:993678. [PMID: 36578827 PMCID: PMC9791262 DOI: 10.3389/fnins.2022.993678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 11/16/2022] [Indexed: 12/14/2022] Open
Abstract
Introduction The gold standard for identification of the epileptogenic zone (EZ) continues to be the visual inspection of electrographic changes around seizures' onset by experienced electroencephalography (EEG) readers. Development of an epileptogenic focus localization tool that can delineate the EZ from analysis of interictal (seizure-free) periods is still an open question of great significance for improved diagnosis (e.g., presurgical evaluation) and treatment of epilepsy (e.g., surgical outcome). Methods We developed an EZ interictal localization algorithm (EZILA) based on novel analysis of intracranial EEG (iEEG) using a univariate periodogram-type power measure, a straight-forward ranking approach, a robust dimensional reduction method and a clustering technique. Ten patients with temporal and extra temporal lobe epilepsies, and matching the inclusion criteria of having iEEG recordings at the epilepsy monitoring unit (EMU) and being Engel Class I ≥12 months post-surgery, were recruited in this study. Results In a nested k-fold cross validation statistical framework, EZILA assigned the highest score to iEEG channels within the EZ in all patients (10/10) during the first hour of the iEEG recordings and up to their first typical clinical seizure in the EMU (i.e., early interictal period). To further validate EZILA's performance, data from two new (Engel Class I) patients were analyzed in a double-blinded fashion; the EZILA successfully localized iEEG channels within the EZ from interictal iEEG in both patients. Discussion Out of the sampled brain regions, iEEG channels in the EZ were most frequently and maximally active in seizure-free (interictal) periods across patients in specific narrow gamma frequency band (∼60-80 Hz), which we have termed focal frequency band (FFB). These findings are consistent with the hypothesis that the EZ may interictally be regulated (controlled) by surrounding inhibitory neurons with resonance characteristics within this narrow gamma band.
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Affiliation(s)
- Omar A. Alamoudi
- Biomedical Engineering Program, Faculty of Engineering, King Abdulaziz University, Jeddah, Saudi Arabia,Neurology Department, Texas Institute for Restorative Neurotechnologies (TIRN), University of Texas Medical School, Houston, TX, United States,*Correspondence: Omar A. Alamoudi,
| | - Adeel Ilyas
- Neurology Department, Texas Institute for Restorative Neurotechnologies (TIRN), University of Texas Medical School, Houston, TX, United States,Department of Neurological Surgery, University of Alabama at Birmingham, Birmingham, AL, United States,Vivian L. Smith Department of Neurosurgery, McGovern Medical School at University of Texas (UT) Health Houston, Houston, TX, United States
| | - Sandipan Pati
- Neurology Department, Texas Institute for Restorative Neurotechnologies (TIRN), University of Texas Medical School, Houston, TX, United States
| | - Leon Iasemidis
- Biomedical Engineering Department, Arizona State University, Tempe, AZ, United States,Department of Translational Neuroscience, Barrow Neurological Institute, Phoenix, AZ, United States
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18
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Liaci C, Camera M, Zamboni V, Sarò G, Ammoni A, Parmigiani E, Ponzoni L, Hidisoglu E, Chiantia G, Marcantoni A, Giustetto M, Tomagra G, Carabelli V, Torelli F, Sala M, Yanagawa Y, Obata K, Hirsch E, Merlo GR. Loss of ARHGAP15 affects the directional control of migrating interneurons in the embryonic cortex and increases susceptibility to epilepsy. Front Cell Dev Biol 2022; 10:875468. [PMID: 36568982 PMCID: PMC9774038 DOI: 10.3389/fcell.2022.875468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 11/07/2022] [Indexed: 12/13/2022] Open
Abstract
GTPases of the Rho family are components of signaling pathways linking extracellular signals to the control of cytoskeleton dynamics. Among these, RAC1 plays key roles during brain development, ranging from neuronal migration to neuritogenesis, synaptogenesis, and plasticity. RAC1 activity is positively and negatively controlled by guanine nucleotide exchange factors (GEFs), guanosine nucleotide dissociation inhibitors (GDIs), and GTPase-activating proteins (GAPs), but the specific role of each regulator in vivo is poorly known. ARHGAP15 is a RAC1-specific GAP expressed during development in a fraction of migrating cortical interneurons (CINs) and in the majority of adult CINs. During development, loss of ARHGAP15 causes altered directionality of the leading process of tangentially migrating CINs, along with altered morphology in vitro. Likewise, time-lapse imaging of embryonic CINs revealed a poorly coordinated directional control during radial migration, possibly due to a hyper-exploratory behavior. In the adult cortex, the observed defects lead to subtle alteration in the distribution of CALB2-, SST-, and VIP-positive interneurons. Adult Arhgap15-knock-out mice also show reduced CINs intrinsic excitability, spontaneous subclinical seizures, and increased susceptibility to the pro-epileptic drug pilocarpine. These results indicate that ARHGAP15 imposes a fine negative regulation on RAC1 that is required for morphological maturation and directional control during CIN migration, with consequences on their laminar distribution and inhibitory function.
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Affiliation(s)
- Carla Liaci
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | - Mattia Camera
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | - Valentina Zamboni
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | - Gabriella Sarò
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | - Alessandra Ammoni
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | | | - Luisa Ponzoni
- Neuroscience Institute, Consiglio Nazionale Ricerche, Milan, Italy
| | - Enis Hidisoglu
- Department of Drug Science, NIS Center, University of Turin, Turin, Italy
| | - Giuseppe Chiantia
- Department of Neuroscience and National Institute of Neuroscience, University of Turin, Turin, Italy
| | - Andrea Marcantoni
- Department of Drug Science, NIS Center, University of Turin, Turin, Italy
| | - Maurizio Giustetto
- Department of Neuroscience and National Institute of Neuroscience, University of Turin, Turin, Italy
| | - Giulia Tomagra
- Department of Drug Science, NIS Center, University of Turin, Turin, Italy
| | | | - Federico Torelli
- Institute for Physiology I, Medical Faculty, Albert-Ludwigs-University Freiburg, Freiburg, Germany,Faculty of Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Mariaelvina Sala
- Neuroscience Institute, Consiglio Nazionale Ricerche, Milan, Italy
| | - Yuchio Yanagawa
- Department of Genetic Behavioral Neuroscience, Gunma University, Maebashi, Japan
| | | | - Emilio Hirsch
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy
| | - Giorgio R. Merlo
- Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin, Italy,*Correspondence: Giorgio R. Merlo,
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19
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Gill BJA, Khan FA, Goldberg AR, Merricks EM, Wu X, Sosunov AA, Sudhakar TD, Dovas A, Lado W, Michalak AJ, Teoh JJ, Liou JY, Frankel WN, McKhann GM, Canoll P, Schevon CA. Single unit analysis and wide-field imaging reveal alterations in excitatory and inhibitory neurons in glioma. Brain 2022; 145:3666-3680. [PMID: 35552612 PMCID: PMC10202150 DOI: 10.1093/brain/awac168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 02/05/2022] [Accepted: 04/27/2022] [Indexed: 11/14/2022] Open
Abstract
While several studies have attributed the development of tumour-associated seizures to an excitatory-inhibitory imbalance, we have yet to resolve the spatiotemporal interplay between different types of neuron in glioma-infiltrated cortex. Herein, we combined methods for single unit analysis of microelectrode array recordings with wide-field optical mapping of Thy1-GCaMP pyramidal cells in an ex vivo acute slice model of diffusely infiltrating glioma. This enabled simultaneous tracking of individual neurons from both excitatory and inhibitory populations throughout seizure-like events. Moreover, our approach allowed for observation of how the crosstalk between these neurons varied spatially, as we recorded across an extended region of glioma-infiltrated cortex. In tumour-bearing slices, we observed marked alterations in single units classified as putative fast-spiking interneurons, including reduced firing, activity concentrated within excitatory bursts and deficits in local inhibition. These results were correlated with increases in overall excitability. Mechanistic perturbation of this system with the mTOR inhibitor AZD8055 revealed increased firing of putative fast-spiking interneurons and restoration of local inhibition, with concomitant decreases in overall excitability. Altogether, our findings suggest that diffusely infiltrating glioma affect the interplay between excitatory and inhibitory neuronal populations in a reversible manner, highlighting a prominent role for functional mechanisms linked to mTOR activation.
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Affiliation(s)
- Brian J A Gill
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Farhan A Khan
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Alexander R Goldberg
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Edward M Merricks
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Xiaoping Wu
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Alexander A Sosunov
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Tejaswi D Sudhakar
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Athanassios Dovas
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Wudu Lado
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Andrew J Michalak
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jia Jie Teoh
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Jyun-you Liou
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Wayne N Frankel
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY 10032, USA
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Peter Canoll
- Department of Pathology and Cell Biology, Irving Cancer Research Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Catherine A Schevon
- Department of Neurology, Columbia University Irving Medical Center, New York, NY 10032, USA
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20
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Thouta S, Waldbrook MG, Lin S, Mahadevan A, Mezeyova J, Soriano M, Versi P, Goodchild SJ, Parrish RR. Pharmacological determination of the fractional block of Nav channels required to impair neuronal excitability and ex vivo seizures. Front Cell Neurosci 2022; 16:964691. [PMID: 36246527 PMCID: PMC9557217 DOI: 10.3389/fncel.2022.964691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/31/2022] [Indexed: 11/13/2022] Open
Abstract
Voltage-gated sodium channels (Nav) are essential for the initiation and propagation of action potentials in neurons. Of the nine human channel subtypes, Nav1.1, Nav1.2 and Nav1.6 are prominently expressed in the adult central nervous system (CNS). All three of these sodium channel subtypes are sensitive to block by the neurotoxin tetrodotoxin (TTX), with TTX being almost equipotent on all three subtypes. In the present study we have used TTX to determine the fractional block of Nav channels required to impair action potential firing in pyramidal neurons and reduce network seizure-like activity. Using automated patch-clamp electrophysiology, we first determined the IC50s of TTX on mouse Nav1.1, Nav1.2 and Nav1.6 channels expressed in HEK cells, demonstrating this to be consistent with previously published data on human orthologs. We then compared this data to the potency of block of Nav current measured in pyramidal neurons from neocortical brain slices. Interestingly, we found that it requires nearly 10-fold greater concentration of TTX over the IC50 to induce significant block of action potentials using a current-step protocol. In contrast, concentrations near the IC50 resulted in a significant reduction in AP firing and increase in rheobase using a ramp protocol. Surprisingly, a 20% reduction in action potential generation observed with 3 nM TTX resulted in significant block of seizure-like activity in the 0 Mg2+ model of epilepsy. Additionally, we found that approximately 50% block in pyramidal cell intrinsic excitability is sufficient to completely block all seizure-like events. Furthermore, we also show that the anticonvulsant drug phenytoin blocked seizure-like events in a manner similar to TTX. These data serve as a critical starting point in understanding how fractional block of Nav channels affect intrinsic neuronal excitability and seizure-like activity. It further suggests that seizures can be controlled without significantly compromising intrinsic neuronal activity and determines the required fold over IC50 for novel and clinically relevant Nav channel blockers to produce efficacy and limit side effects.
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Affiliation(s)
- Samrat Thouta
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
| | - Matthew G. Waldbrook
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
| | - Sophia Lin
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
| | - Arjun Mahadevan
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
| | - Janette Mezeyova
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
| | - Maegan Soriano
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
| | - Pareesa Versi
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
| | - Samuel J. Goodchild
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
| | - R. Ryley Parrish
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
- Department of Cell Biology and Physiology, Brigham Young University, Provo, UT, United States
- *Correspondence: R. Ryley Parrish,
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Mahadevan A, Codadu NK, Parrish RR. Xenon LFP Analysis Platform Is a Novel Graphical User Interface for Analysis of Local Field Potential From Large-Scale MEA Recordings. Front Neurosci 2022; 16:904931. [PMID: 35844228 PMCID: PMC9285004 DOI: 10.3389/fnins.2022.904931] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 06/08/2022] [Indexed: 11/24/2022] Open
Abstract
High-density multi-electrode array (HD-MEA) has enabled neuronal measurements at high spatial resolution to record local field potentials (LFP), extracellular action potentials, and network-wide extracellular recording on an extended spatial scale. While we have advanced recording systems with over 4,000 electrodes capable of recording data at over 20 kHz, it still presents computational challenges to handle, process, extract, and view information from these large recordings. We have created a computational method, and an open-source toolkit built in Python, rendered on a web browser using Plotly’s Dash for extracting and viewing the data and creating interactive visualization. In addition to extracting and viewing entire or small chunks of data sampled at lower or higher frequencies, respectively, it provides a framework to collect user inputs, analyze channel groups, generate raster plots, view quick summary measures for LFP activity, detect and isolate noise channels, and generate plots and visualization in both time and frequency domain. Incorporated into our Graphical User Interface (GUI), we also created a novel seizure detection method, which can be used to detect the onset of seizures in all or a selected group of channels and provide the following measures of seizures: distance, duration, and propagation across the region of interest. We demonstrate the utility of this toolkit, using datasets collected from an HD-MEA device comprising of 4,096 recording electrodes. For the current analysis, we demonstrate the toolkit and methods with a low sampling frequency dataset (300 Hz) and a group of approximately 400 channels. Using this toolkit, we present novel data demonstrating increased seizure propagation speed from brain slices of Scn1aHet mice compared to littermate controls. While there have been advances in HD-MEA recording systems with high spatial and temporal resolution, limited tools are available for researchers to view and process these big datasets. We now provide a user-friendly toolkit to analyze LFP activity obtained from large-scale MEA recordings with translatable applications to EEG recordings and demonstrate the utility of this new graphic user interface with novel biological findings.
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Affiliation(s)
- Arjun Mahadevan
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
| | - Neela K. Codadu
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, United Kingdom
| | - R. Ryley Parrish
- Department of Cellular and Molecular Biology, Xenon Pharmaceuticals Inc., Burnaby, BC, Canada
- *Correspondence: R. Ryley Parrish,
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Lignani G. Unblock the Block! Preventing Inhibitory Failure to Maintain Inhibitory Restraint. Epilepsy Curr 2022; 22:244-245. [PMID: 36187146 PMCID: PMC9483764 DOI: 10.1177/15357597221098808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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23
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Meneghini S, Modena D, Colombo G, Coatti A, Milani N, Madaschi L, Amadeo A, Becchetti A. The β2V287L nicotinic subunit linked to sleep-related epilepsy differently affects fast-spiking and regular spiking somatostatin-expressing neurons in murine prefrontal cortex. Prog Neurobiol 2022; 214:102279. [DOI: 10.1016/j.pneurobio.2022.102279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 04/02/2022] [Accepted: 04/28/2022] [Indexed: 12/01/2022]
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24
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Lado WE, Xu X, Hablitz JJ. Modulation of Epileptiform Activity by Three Subgroups of GABAergic Interneurons in Mouse Somatosensory Cortex. Epilepsy Res 2022; 183:106937. [DOI: 10.1016/j.eplepsyres.2022.106937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 04/05/2022] [Accepted: 04/24/2022] [Indexed: 11/29/2022]
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Kim JE, Kang TC. Blockade of TASK-1 Channel Improves the Efficacy of Levetiracetam in Chronically Epileptic Rats. Biomedicines 2022; 10:biomedicines10040787. [PMID: 35453538 PMCID: PMC9030960 DOI: 10.3390/biomedicines10040787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/21/2022] [Accepted: 03/26/2022] [Indexed: 11/29/2022] Open
Abstract
Tandem of P domains in a weak inwardly rectifying K+ channel (TWIK)-related acid sensitive K+-1 channel (TASK-1) is an outwardly rectifying K+ channel that acts in response to extracellular pH. TASK-1 is upregulated in the astrocytes (particularly in the CA1 region) of the hippocampi of patients with temporal lobe epilepsy and chronically epilepsy rats. Since levetiracetam (LEV) is an effective inhibitor for carbonic anhydrase, which has a pivotal role in buffering of extracellular pH, it is likely that the anti-epileptic action of LEV may be relevant to TASK-1 inhibition, which remains to be elusive. In the present study, we found that LEV diminished the upregulated TASK-1 expression in the CA1 astrocytes of responders (whose seizure activities were responsive to LEV), but not non-responders (whose seizure activities were not controlled by LEV) in chronically epileptic rats. ML365 (a selective TASK-1 inhibitor) only reduced seizure duration in LEV non-responders, concomitant with astroglial TASK-1 downregulation. Furthermore, ML365 co-treatment with LEV decreased the duration, frequency and severity of spontaneous seizures in non-responders to LEV. To the best of our knowledge, our findings suggest, for the first time, that the up-regulation of TASK-1 expression in CA1 astrocytes may be involved in refractory seizures in response to LEV. This may be a potential target to improve responsiveness to LEV.
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Affiliation(s)
| | - Tae-Cheon Kang
- Correspondence: ; Tel.: +82-33-248-2524; Fax: +82-33-248-2525
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26
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Drexel M, Rahimi S, Sperk G. Silencing of hippocampal somatostatin interneurons induces recurrent spontaneous limbic seizures in mice. Neuroscience 2022; 487:155-165. [DOI: 10.1016/j.neuroscience.2022.02.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/11/2022] [Accepted: 02/08/2022] [Indexed: 12/22/2022]
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Chizhov AV, Amakhin DV, Smirnova EY, Zaitsev AV. Ictal wavefront propagation in slices and simulations with conductance-based refractory density model. PLoS Comput Biol 2022; 18:e1009782. [PMID: 35041661 PMCID: PMC8797236 DOI: 10.1371/journal.pcbi.1009782] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 01/28/2022] [Accepted: 12/21/2021] [Indexed: 12/04/2022] Open
Abstract
The mechanisms determining ictal discharge (ID) propagation are still not clear. In the present study, we aimed to examine these mechanisms in animal and mathematical models of epileptiform activity. Using double-patch and extracellular potassium ion concentration recordings in rat hippocampal-cortical slices, we observed that IDs moved at a speed of about 1 mm/s or less. The mechanisms of such slow propagation have been studied with a mathematical, conductance-based refractory density (CBRD) model that describes the GABA- and glutamatergic neuronal populations’ interactions and ion dynamics in brain tissue. The modeling study reveals two main factors triggerring IDs: (i) increased interneuronal activity leading to chloride ion accumulation and a consequent depolarizing GABAergic effect and (ii) the elevation of extracellular potassium ion concentration. The local synaptic transmission followed by local potassium ion extrusion and GABA receptor-mediated chloride ion accumulation underlies the ID wavefront’s propagation. In contrast, potassium ion diffusion in the extracellular space is slower and does not affect ID’s speed. The short discharges, constituting the ID, propagate much faster than the ID front. The accumulation of sodium ions inside neurons due to their hyperactivity and glutamatergic currents boosts the Na+/K+ pump, which terminates the ID. Knowledge of the mechanism of ID generation and propagation contributes to the development of new treatments against epilepsy. During an epileptic seizure, neuronal excitation spreads across the brain tissue and is accompanied by significant changes in ionic concentrations. Ictal discharge front spreads at low speeds, less than 1 mm/s. Mechanisms underlying this phenomenon are not yet well understood. We study these mechanisms using electrophysiological recordings in brain slices and computer simulations. Our detailed biophysical model describing neuronal populations’ interaction, spatial propagation, and ionic dynamics reproduces the generation and propagation of spontaneously repeating ictal discharges. The simulations are consistent with our recordings of the electrical activity and the extracellular potassium ion concentration. We distinguished between the two alternative mechanisms of the ictal wavefront propagation: (i) the diffusion of potassium ions released from excited neurons, which depolarizes distant neurons and thus supports excitation, and (ii) the axonal spread of excitation followed by the local extracellular potassium ion accumulation that supports the excitation. Our simulations provide evidence in favor of the latter mechanism. Our experiment-based modeling contributes to a mathematical description of brain tissue functioning and potentially contributes to developing new treatments against epilepsy.
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Affiliation(s)
- Anton V. Chizhov
- Laboratory of Molecular Mechanisms of Neural Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, Saint Petersburg, Russia
- Computational Physics Laboratory, Ioffe Institute, Saint Petersburg, Russia
- * E-mail:
| | - Dmitry V. Amakhin
- Laboratory of Molecular Mechanisms of Neural Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, Saint Petersburg, Russia
| | - Elena Yu. Smirnova
- Laboratory of Molecular Mechanisms of Neural Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, Saint Petersburg, Russia
- Computational Physics Laboratory, Ioffe Institute, Saint Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Saint Petersburg, Russia
| | - Aleksey V. Zaitsev
- Laboratory of Molecular Mechanisms of Neural Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, Saint Petersburg, Russia
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Disrupting Epileptiform Activity by Preventing Parvalbumin Interneuron Depolarization Block. J Neurosci 2021; 41:9452-9465. [PMID: 34611025 DOI: 10.1523/jneurosci.1002-20.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 09/21/2021] [Accepted: 09/26/2021] [Indexed: 11/21/2022] Open
Abstract
Inhibitory synaptic mechanisms oppose epileptic network activity in the brain. The breakdown in this inhibitory restraint and propagation of seizure activity has been linked to the overwhelming of feedforward inhibition, which is provided in large part by parvalbumin-expressing (PV) interneurons in the cortex. The underlying cellular processes therefore represent potential targets for understanding and preventing the propagation of seizure activity. Here we use an optogenetic strategy to test the hypothesis that depolarization block in PV interneurons is a significant factor during the loss of inhibitory restraint. Depolarization block results from the inactivation of voltage-gated sodium channels and leads to impaired action potential firing. We used focal NMDA stimulation to elicit reproducible epileptiform discharges in hippocampal organotypic brain slices from male and female mice and combined this with targeted recordings from defined neuronal populations. Simultaneous patch-clamp recordings from PV interneurons and pyramidal neurons revealed epileptiform activity that was associated with an overwhelming of inhibitory synaptic mechanisms and the emergence of a partial, and then complete, depolarization block in PV interneurons. To counteract this depolarization block, we developed protocols for eliciting pulsed membrane hyperpolarization via the inhibitory opsin, archaerhodopsin. This optical approach was effective in counteracting cumulative inactivation of voltage-gated channels, maintaining PV interneuron action potential firing properties during the inhibitory restraint period, and reducing the probability of initiating epileptiform activity. These experiments support the idea that depolarization block is a point of weakness in feedforward inhibitory synaptic mechanisms and represents a target for preventing the initiation and spread of seizure activity.SIGNIFICANCE STATEMENT GABAA receptor-mediated synaptic transmission opposes seizure activity by establishing an inhibitory restraint against spreading excitation. Parvalbumin-expressing (PV) interneurons contribute significantly to this inhibitory restraint, but it has been suggested that these cells are overwhelmed as they enter a state of "depolarization block." Here we test the importance of this process by devising an optogenetic strategy to selectively relieve depolarization block in PV interneurons. By inducing brief membrane hyperpolarization, we show that it is possible to reduce depolarization block in PV interneurons, maintain their action potential firing in the face of strong excitation, and disrupt epileptiform activity in an in vitro model. This represents a proof of principle that targeting rate-limiting processes can strengthen the inhibitory restraint of epileptiform activity.
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Somatostatin-Positive Interneurons Contribute to Seizures in SCN8A Epileptic Encephalopathy. J Neurosci 2021; 41:9257-9273. [PMID: 34544834 DOI: 10.1523/jneurosci.0718-21.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
SCN8A epileptic encephalopathy is a devastating epilepsy syndrome caused by mutant SCN8A, which encodes the voltage-gated sodium channel NaV1.6. To date, it is unclear if and how inhibitory interneurons, which express NaV1.6, influence disease pathology. Using both sexes of a transgenic mouse model of SCN8A epileptic encephalopathy, we found that selective expression of the R1872W SCN8A mutation in somatostatin (SST) interneurons was sufficient to convey susceptibility to audiogenic seizures. Patch-clamp electrophysiology experiments revealed that SST interneurons from mutant mice were hyperexcitable but hypersensitive to action potential failure via depolarization block under normal and seizure-like conditions. Remarkably, GqDREADD-mediated activation of WT SST interneurons resulted in prolonged electrographic seizures and was accompanied by SST hyperexcitability and depolarization block. Aberrantly large persistent sodium currents, a hallmark of SCN8A mutations, were observed and were found to contribute directly to aberrant SST physiology in computational modeling and pharmacological experiments. These novel findings demonstrate a critical and previously unidentified contribution of SST interneurons to seizure generation not only in SCN8A epileptic encephalopathy, but epilepsy in general.SIGNIFICANCE STATEMENT SCN8A epileptic encephalopathy is a devastating neurological disorder that results from de novo mutations in the sodium channel isoform Nav1.6. Inhibitory neurons express NaV1.6, yet their contribution to seizure generation in SCN8A epileptic encephalopathy has not been determined. We show that mice expressing a human-derived SCN8A variant (R1872W) selectively in somatostatin (SST) interneurons have audiogenic seizures. Physiological recordings from SST interneurons show that SCN8A mutations lead to an elevated persistent sodium current which drives initial hyperexcitability, followed by premature action potential failure because of depolarization block. Furthermore, chemogenetic activation of WT SST interneurons leads to audiogenic seizure activity. These findings provide new insight into the importance of SST inhibitory interneurons in seizure initiation, not only in SCN8A epileptic encephalopathy, but for epilepsy broadly.
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Lemaire L, Desroches M, Krupa M, Pizzamiglio L, Scalmani P, Mantegazza M. Modeling NaV1.1/SCN1A sodium channel mutations in a microcircuit with realistic ion concentration dynamics suggests differential GABAergic mechanisms leading to hyperexcitability in epilepsy and hemiplegic migraine. PLoS Comput Biol 2021; 17:e1009239. [PMID: 34314446 PMCID: PMC8345895 DOI: 10.1371/journal.pcbi.1009239] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 08/06/2021] [Accepted: 07/02/2021] [Indexed: 11/19/2022] Open
Abstract
Loss of function mutations of SCN1A, the gene coding for the voltage-gated sodium channel NaV1.1, cause different types of epilepsy, whereas gain of function mutations cause sporadic and familial hemiplegic migraine type 3 (FHM-3). However, it is not clear yet how these opposite effects can induce paroxysmal pathological activities involving neuronal networks’ hyperexcitability that are specific of epilepsy (seizures) or migraine (cortical spreading depolarization, CSD). To better understand differential mechanisms leading to the initiation of these pathological activities, we used a two-neuron conductance-based model of interconnected GABAergic and pyramidal glutamatergic neurons, in which we incorporated ionic concentration dynamics in both neurons. We modeled FHM-3 mutations by increasing the persistent sodium current in the interneuron and epileptogenic mutations by decreasing the sodium conductance in the interneuron. Therefore, we studied both FHM-3 and epileptogenic mutations within the same framework, modifying only two parameters. In our model, the key effect of gain of function FHM-3 mutations is ion fluxes modification at each action potential (in particular the larger activation of voltage-gated potassium channels induced by the NaV1.1 gain of function), and the resulting CSD-triggering extracellular potassium accumulation, which is not caused only by modifications of firing frequency. Loss of function epileptogenic mutations, on the other hand, increase GABAergic neurons’ susceptibility to depolarization block, without major modifications of firing frequency before it. Our modeling results connect qualitatively to experimental data: potassium accumulation in the case of FHM-3 mutations and facilitated depolarization block of the GABAergic neuron in the case of epileptogenic mutations. Both these effects can lead to pyramidal neuron hyperexcitability, inducing in the migraine condition depolarization block of both the GABAergic and the pyramidal neuron. Overall, our findings suggest different mechanisms of network hyperexcitability for migraine and epileptogenic NaV1.1 mutations, implying that the modifications of firing frequency may not be the only relevant pathological mechanism. The voltage-gated sodium channel NaV1.1 is a major target of human mutations implicated in different pathologies. In particular, mutations identified in certain types of epilepsy cause loss of function of the channel, whereas mutations identified in certain types of migraine (in which spreading depolarizations of the cortical circuits of the brain are involved) cause instead gain of function. Here, we study dysfunctions induced by these differential effects in a two-neuron (GABAergic and pyramidal) conductance-based model with dynamic ion concentrations. We obtain results that can be related to experimental findings in both situations. Namely, extracellular potassium accumulation induced by the activity of the GABAergic neuron in the case of CSD, and higher propensity of the GABAergic neuron to depolarization block in the epileptogenic scenario, without significant modifications of its firing frequency prior to it. Both scenarios can induce hyperexcitability of the pyramidal neuron, leading in the migraine condition to depolarization block of both the GABAergic and the pyramidal neuron. Our results are successfully confronted to experimental data and suggest that modification of firing frequency is not the only key mechanism in these pathologies of neuronal excitability.
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Affiliation(s)
- Louisiane Lemaire
- Inria Sophia Antipolis Méditerranée Research Centre, MathNeuro Team, Valbonne-Sophia Antipolis, France
- Université Côte d’Azur, Nice, France
- * E-mail: (LL); (MM)
| | - Mathieu Desroches
- Inria Sophia Antipolis Méditerranée Research Centre, MathNeuro Team, Valbonne-Sophia Antipolis, France
- Université Côte d’Azur, Nice, France
| | - Martin Krupa
- Inria Sophia Antipolis Méditerranée Research Centre, MathNeuro Team, Valbonne-Sophia Antipolis, France
- Université Côte d’Azur, Laboratoire Jean-Alexandre Dieudonné, Nice, France
| | - Lara Pizzamiglio
- Université Côte d’Azur, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- CNRS UMR7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Paolo Scalmani
- U.O. VII Clinical and Experimental Epileptology, Foundation IRCCS Neurological Institute Carlo Besta, Milan, Italy
| | - Massimo Mantegazza
- Université Côte d’Azur, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- CNRS UMR7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
- * E-mail: (LL); (MM)
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Losi G, Gomez-Gonzalo M, Zonta M, Chiavegato A, Carmignoto G. Cellular and molecular mechanisms of new onset seizure generation. Aging Clin Exp Res 2021; 33:1713-1716. [PMID: 31732960 DOI: 10.1007/s40520-019-01396-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/19/2019] [Indexed: 12/19/2022]
Abstract
New onset epilepsy and seizures are common neurological disorders in aged people, second only to stroke and dementia. They are frequently related to other pathological conditions including stroke, trauma, tumors and neurological diseases whereas in about one-third of cases the origin is unknown. Besides the origin, the cellular and molecular events that suddenly trigger seizures are poorly defined. Using an acute model of seizure generation that better resembles new onset seizures, we studied GABAergic interneurons and astrocytes during seizure generation. We found that seizures are preceded by a GABAergic rhythmic hyperactivity that synchronizes pyramidal neurons by inducing a rebound spiking that favors seizures' onset. Furthermore, the intense activity in GABAergic interneurons evokes Ca2+ elevations in astrocytes that, by releasing glutamate, further excite neuronal network. Elucidating the cellular and molecular events that generate seizures may reveal new targets for treatment of new onset seizures and epilepsy.
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Affiliation(s)
- Gabriele Losi
- Neuroscience Institute, National Research Council (CNR), Viale Giuseppe Colombo 3, Padua, Italy.
- Department of Biomedical Science, University of Padua, via Ugo Bassi 58/B, Padua, Italy.
| | - Marta Gomez-Gonzalo
- Neuroscience Institute, National Research Council (CNR), Viale Giuseppe Colombo 3, Padua, Italy
- Department of Biomedical Science, University of Padua, via Ugo Bassi 58/B, Padua, Italy
| | - Micaela Zonta
- Neuroscience Institute, National Research Council (CNR), Viale Giuseppe Colombo 3, Padua, Italy
- Department of Biomedical Science, University of Padua, via Ugo Bassi 58/B, Padua, Italy
| | - Angela Chiavegato
- Department of Biomedical Science, University of Padua, via Ugo Bassi 58/B, Padua, Italy
| | - Giorgio Carmignoto
- Neuroscience Institute, National Research Council (CNR), Viale Giuseppe Colombo 3, Padua, Italy.
- Department of Biomedical Science, University of Padua, via Ugo Bassi 58/B, Padua, Italy.
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Khateb M, Bosak N, Herskovitz M. The Effect of Anti-seizure Medications on the Propagation of Epileptic Activity: A Review. Front Neurol 2021; 12:674182. [PMID: 34122318 PMCID: PMC8191738 DOI: 10.3389/fneur.2021.674182] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/09/2021] [Indexed: 11/13/2022] Open
Abstract
The propagation of epileptiform events is a highly interesting phenomenon from the pathophysiological point of view, as it involves several mechanisms of recruitment of neural networks. Extensive in vivo and in vitro research has been performed, suggesting that multiple networks as well as cellular candidate mechanisms govern this process, including the co-existence of wave propagation, coupled oscillator dynamics, and more. The clinical importance of seizure propagation stems mainly from the fact that the epileptic manifestations cannot be attributed solely to the activity in the seizure focus itself, but rather to the propagation of epileptic activity to other brain structures. Propagation, especially when causing secondary generalizations, poses a risk to patients due to recurrent falls, traumatic injuries, and poor neurological outcome. Anti-seizure medications (ASMs) affect propagation in diverse ways and with different potencies. Importantly, for drug-resistant patients, targeting seizure propagation may improve the quality of life even without a major reduction in simple focal events. Motivated by the extensive impact of this phenomenon, we sought to review the literature regarding the propagation of epileptic activity and specifically the effect of commonly used ASMs on it. Based on this body of knowledge, we propose a novel classification of ASMs into three main categories: major, minor, and intermediate efficacy in reducing the propagation of epileptiform activity.
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Affiliation(s)
- Mohamed Khateb
- Department of Neurology, Rambam Health Care Campus, Haifa, Israel
| | - Noam Bosak
- Department of Neurology, Rambam Health Care Campus, Haifa, Israel
| | - Moshe Herskovitz
- Department of Neurology, Rambam Health Care Campus, Haifa, Israel.,The Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel
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33
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Lim HK, You N, Bae S, Kang BM, Shon YM, Kim SG, Suh M. Differential contribution of excitatory and inhibitory neurons in shaping neurovascular coupling in different epileptic neural states. J Cereb Blood Flow Metab 2021; 41:1145-1161. [PMID: 32669018 PMCID: PMC8054729 DOI: 10.1177/0271678x20934071] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Understanding the neurovascular coupling (NVC) underlying hemodynamic changes in epilepsy is crucial to properly interpreting functional brain imaging signals associated with epileptic events. However, how excitatory and inhibitory neurons affect vascular responses in different epileptic states remains unknown. We conducted real-time in vivo measurements of cerebral blood flow (CBF), vessel diameter, and excitatory and inhibitory neuronal calcium signals during recurrent focal seizures. During preictal states, decreases in CBF and arteriole diameter were closely related to decreased γ-band local field potential (LFP) power, which was linked to relatively elevated excitatory and reduced inhibitory neuronal activity levels. Notably, this preictal condition was followed by a strengthened ictal event. In particular, the preictal inhibitory activity level was positively correlated with coherent oscillating activity specific to inhibitory neurons. In contrast, ictal states were characterized by elevated synchrony in excitatory neurons. Given these findings, we suggest that excitatory and inhibitory neurons differentially contribute to shaping the ictal and preictal neural states, respectively. Moreover, the preictal vascular activity, alongside with the γ-band, may reflect the relative levels of excitatory and inhibitory neuronal activity, and upcoming ictal activity. Our findings provide useful insights into how perfusion signals of different epileptic states are related in terms of NVC.
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Affiliation(s)
- Hyun-Kyoung Lim
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biological Sciences, Sungkyunkwan University, Suwon, South Korea
| | - Nayeon You
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Sungjun Bae
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Bok-Man Kang
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Young-Min Shon
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Seong-Gi Kim
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Minah Suh
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea.,Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University, Suwon, South Korea.,Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Suwon, South Korea
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34
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Ryu B, Nagappan S, Santos-Valencia F, Lee P, Rodriguez E, Lackie M, Takatoh J, Franks KM. Chronic loss of inhibition in piriform cortex following brief, daily optogenetic stimulation. Cell Rep 2021; 35:109001. [PMID: 33882304 PMCID: PMC8102022 DOI: 10.1016/j.celrep.2021.109001] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 12/10/2020] [Accepted: 03/24/2021] [Indexed: 12/02/2022] Open
Abstract
It is well established that seizures beget seizures, yet the cellular processes that underlie progressive epileptogenesis remain unclear. Here, we use optogenetics to briefly activate targeted populations of mouse piriform cortex (PCx) principal neurons in vivo. After just 3 or 4 days of stimulation, previously subconvulsive stimuli trigger massive, generalized seizures. Highly recurrent allocortices are especially prone to “optokindling.” Optokindling upsets the balance of recurrent excitation and feedback inhibition. To understand how this balance is disrupted, we then selectively reactivate the same neurons in vitro. Surprisingly, we find no evidence of heterosynaptic potentiation; instead, we observe a marked, pathway-specific decrease in feedback inhibition. We find no loss of inhibitory interneurons; rather, decreased GABA synthesis in feedback inhibitory neurons appears to underlie weakened inhibition. Optokindling will allow precise identification of the molecular processes by which brain activity patterns can progressively and pathologically disrupt the balance of cortical excitation and inhibition. Ryu et al. use optogenetics to briefly activate principal neurons in mouse piriform cortex. After 4 days, previously innocuous stimuli evoke massive, generalized seizures. “Optokindling” does not strengthen recurrent excitation; instead, it weakens feedback inhibition by decreasing synaptic cleft GABA concentrations and slowing vesicle refilling, consistent with decreased GABA synthesis.
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Affiliation(s)
- Brendan Ryu
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
| | | | | | - Psyche Lee
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
| | - Erica Rodriguez
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
| | - Meredith Lackie
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
| | - Jun Takatoh
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
| | - Kevin M Franks
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA.
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35
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Identification and quantification of neuronal ensembles in optical imaging experiments. J Neurosci Methods 2020; 351:109046. [PMID: 33359231 DOI: 10.1016/j.jneumeth.2020.109046] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/12/2020] [Accepted: 12/15/2020] [Indexed: 12/30/2022]
Abstract
Recent technical advances in molecular biology and optical imaging have made it possible to record from up to thousands of densely packed neurons in superficial and deep brain regions in vivo, with cellular subtype specificity and high spatiotemporal fidelity. Such optical neurotechnologies are enabling increasingly fine-scaled studies of neuronal circuits and reliably co-active groups of neurons, so-called ensembles. Neuronal ensembles are thought to constitute the basic functional building blocks of brain systems, potentially exhibiting collective computational properties. While the technical framework of in vivo optical imaging and quantification of neuronal activity follows certain widely held standards, analytical methods for study of neuronal co-activity and ensembles lack consensus and are highly varied across the field. Here we provide a comprehensive step-by-step overview of theoretical, experimental, and analytical considerations for the identification and quantification of neuronal ensemble dynamics in high-resolution in vivo optical imaging studies.
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Neuronal Firing and Waveform Alterations through Ictal Recruitment in Humans. J Neurosci 2020; 41:766-779. [PMID: 33229500 DOI: 10.1523/jneurosci.0417-20.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 10/29/2020] [Accepted: 11/11/2020] [Indexed: 01/04/2023] Open
Abstract
Analyzing neuronal activity during human seizures is pivotal to understanding mechanisms of seizure onset and propagation. These analyses, however, invariably using extracellular recordings, are greatly hindered by various phenomena that are well established in animal studies: changes in local ionic concentration, changes in ionic conductance, and intense, hypersynchronous firing. The first two alter the action potential waveform, whereas the third increases the "noise"; all three factors confound attempts to detect and classify single neurons. To address these analytical difficulties, we developed a novel template-matching-based spike sorting method, which enabled identification of 1239 single neurons in 27 patients (13 female) with intractable focal epilepsy, that were tracked throughout multiple seizures. These new analyses showed continued neuronal firing with widespread intense activation and stereotyped action potential alterations in tissue that was invaded by the seizure: neurons displayed increased waveform duration (p < 0.001) and reduced amplitude (p < 0.001), consistent with prior animal studies. By contrast, neurons in "penumbral" regions (those receiving intense local synaptic drive from the seizure but without neuronal evidence of local seizure invasion) showed stable waveforms. All neurons returned to their preictal waveforms after seizure termination. We conclude that the distinction between "core" territories invaded by the seizure versus "penumbral" territories is evident at the level of single neurons. Furthermore, the increased waveform duration and decreased waveform amplitude are neuron-intrinsic hallmarks of seizure invasion that impede traditional spike sorting and could be used as defining characteristics of local recruitment.SIGNIFICANCE STATEMENT Animal studies consistently show marked changes in action potential waveform during epileptic discharges, but acquiring similar evidence in humans has proven difficult. Assessing neuronal involvement in ictal events is pivotal to understanding seizure dynamics and in defining clinical localization of epileptic pathology. Using a novel method to track neuronal firing, we analyzed microelectrode array recordings of spontaneously occurring human seizures, and here report two dichotomous activity patterns. In cortex that is recruited to the seizure, neuronal firing rates increase and waveforms become longer in duration and shorter in amplitude as the neurons are recruited to the seizure, while penumbral tissue shows stable action potentials, in keeping with the "dual territory" model of seizure dynamics.
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Serrano-Reyes M, García-Vilchis B, Reyes-Chapero R, Cáceres-Chávez VA, Tapia D, Galarraga E, Bargas J. Spontaneous Activity of Neuronal Ensembles in Mouse Motor Cortex: Changes after GABAergic Blockade. Neuroscience 2020; 446:304-322. [PMID: 32860933 DOI: 10.1016/j.neuroscience.2020.08.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/02/2020] [Accepted: 08/18/2020] [Indexed: 01/12/2023]
Abstract
The mouse motor cortex exhibits spontaneous activity in the form of temporal sequences of neuronal ensembles in vitro without the need of tissue stimulation. These neuronal ensembles are defined as groups of neurons with a strong correlation between its firing patterns, generating what appears to be a predetermined neural conduction mode that needs study. Each ensemble is commonly accompanied by one or more parvalbumin expressing neurons (PV+) or fast spiking interneurons. Many of these interneurons have functional connections between them, helping to form a circuit configuration similar to a small-world network. However, rich club metrics show that most connected neurons are neurons not expressing parvalbumin, mainly pyramidal neurons (PV-) suggesting feed-forward propagation through pyramidal cells. Ensembles with PV+ neurons are connected to these hubs. When ligand-gated fast GABAergic transmission is blocked, temporal sequences of ensembles collapse into a unique synchronous and recurrent ensemble, showing the need of inhibition for coding cortical spontaneous activity. This new ensemble has a duration and electrophysiological characteristics of brief recurrent interictal epileptiform discharges (IEDs) composed by the coactivity of both PV- and PV+ neurons, demonstrating that GABA transmission impedes its occurrence. Synchronous ensembles are clearly divided into two clusters one of them lasting longer and mainly composed by PV+ neurons. Because an ictal-like event was not recorded after several minutes of IEDs recording, it is inferred that an external stimulus and/or fast GABA transmission are necessary for its appearance, making this preparation ideal to study both the neuronal machinery to encode cortical spontaneous activity and its transformation into brief non-ictal epileptiform discharges.
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Affiliation(s)
- Miguel Serrano-Reyes
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City 04510, Mexico
| | - Brisa García-Vilchis
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City 04510, Mexico
| | - Rosa Reyes-Chapero
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City 04510, Mexico
| | | | - Dagoberto Tapia
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City 04510, Mexico
| | - Elvira Galarraga
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City 04510, Mexico
| | - José Bargas
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City 04510, Mexico.
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38
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Tsai CM, Chang SF, Chang H. Transcranial photobiomodulation attenuates pentylenetetrazole-induced status epilepticus in peripubertal rats. JOURNAL OF BIOPHOTONICS 2020; 13:e202000095. [PMID: 32362066 DOI: 10.1002/jbio.202000095] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 04/25/2020] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
Convulsive status epilepticus is the most common neurological emergency in children. Transcranial photobiomodulation (tPBM) reverses elevated rodent neurotransmitters after status epilepticus (SE) yet whether tPBM can attenuate seizure behaviors remains unknown. Here, we applied near-infrared laser at wavelength 808 nm transcranially to peripubertal Sprague-Dawley rats prior to pentylenetetrazole (PTZ) injection. Hematoxylin-eosin, immunofluorescence (IF) staining with anti-parvalbumin (PV) and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay after IF staining was performed. Behaviorally, tPBM attenuated the mean seizure score and reduced the incidence of SE and mortality. Histochemically, tPBM reduced dark neurons in the cortex, hippocampus, thalamus and hypothalamus, lessened the apoptotic ratio of parvalbumin-positive interneurons (PV-INs) and alleviated the aberrant extent of PV-positive unstained somata of PCs in the hippocampus. Conclusively, tPBM attenuated PTZ-induced seizures, SE and mortality in peripubertal rats and reduced PTZ-induced neuronal injury, apoptosis of PV-INs and preserved PV positive perisomatic inhibitory network in the hippocampus.
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Affiliation(s)
- Chung-Min Tsai
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Shwu-Fen Chang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Hsi Chang
- Department of Pediatrics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Department of Pediatrics, Taipei Medical University Hospital, Taipei, Taiwan
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39
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Novorolsky RJ, Nichols M, Kim JS, Pavlov EV, J Woods J, Wilson JJ, Robertson GS. The cell-permeable mitochondrial calcium uniporter inhibitor Ru265 preserves cortical neuron respiration after lethal oxygen glucose deprivation and reduces hypoxic/ischemic brain injury. J Cereb Blood Flow Metab 2020; 40:1172-1181. [PMID: 32126877 PMCID: PMC7238378 DOI: 10.1177/0271678x20908523] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 12/18/2019] [Accepted: 01/31/2020] [Indexed: 01/20/2023]
Abstract
The mitochondrial calcium (Ca2+) uniporter (MCU) mediates high-capacity mitochondrial Ca2+ uptake implicated in ischemic/reperfusion cell death. We have recently shown that inducible MCU ablation in Thy1-expressing neurons renders mice resistant to sensorimotor deficits and forebrain neuron loss in a model of hypoxic/ischemic (HI) brain injury. These findings encouraged us to compare the neuroprotective effects of Ru360 and the recently identified cell permeable MCU inhibitor Ru265. Unlike Ru360, Ru265 (2-10 µM) reached intracellular concentrations in cultured cortical neurons that preserved cell viability, blocked the protease activity of Ca2+-dependent calpains and maintained mitochondrial respiration and glycolysis after a lethal period of oxygen-glucose deprivation (OGD). Intraperitoneal (i.p.) injection of adult male C57Bl/6 mice with Ru265 (3 mg/kg) also suppressed HI-induced sensorimotor deficits and brain injury. However, higher doses of Ru265 (10 and 30 mg/kg, i.p.) produced dose-dependent increases in the frequency and duration of seizure-like behaviours. Ru265 is proposed to promote convulsions by reducing Ca2+ buffering and energy production in highly energetic interneurons that suppress brain seizure activity. These findings support the therapeutic potential of MCU inhibition in the treatment of ischemic stroke but also indicate that such clinical translation will require drug delivery strategies which mitigate the pro-convulsant effects of Ru265.
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Affiliation(s)
- Robyn J Novorolsky
- Department of Pharmacology, Faculty of Medicine,
Dalhousie University, Life Sciences Research Institute, Halifax,
Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie
University, Life Sciences Research Institute, Halifax, Canada
| | - Matthew Nichols
- Department of Pharmacology, Faculty of Medicine,
Dalhousie University, Life Sciences Research Institute, Halifax,
Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie
University, Life Sciences Research Institute, Halifax, Canada
| | - Jong S Kim
- Department of Community Health and Epidemiology,
Faculty of Medicine, Centre for Clinical Research, Dalhousie
University, Halifax, Nova Scotia, Canada
- Department of Microbiology, Faculty of Medicine,
Centre for Clinical Research, Dalhousie University, Nova Scotia,
Canada
| | - Evgeny V Pavlov
- Department of Basic Sciences, College of Dentistry,
New York University, NY, USA
| | - Joshua J Woods
- Department of Chemistry and Chemical Biology, Cornell
University, Baker Laboratory, Ithaca, NY, USA
| | - Justin J Wilson
- Department of Chemistry and Chemical Biology, Cornell
University, Baker Laboratory, Ithaca, NY, USA
| | - George S Robertson
- Department of Pharmacology, Faculty of Medicine,
Dalhousie University, Life Sciences Research Institute, Halifax,
Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie
University, Life Sciences Research Institute, Halifax, Canada
- Department of Psychiatry, Faculty of Medicine,
Dalhousie University, Life Sciences Research Institute, Halifax,
Canada
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40
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Burman RJ, Selfe JS, Lee JH, van den Berg M, Calin A, Codadu NK, Wright R, Newey SE, Parrish RR, Katz AA, Wilmshurst JM, Akerman CJ, Trevelyan AJ, Raimondo JV. Excitatory GABAergic signalling is associated with benzodiazepine resistance in status epilepticus. Brain 2020; 142:3482-3501. [PMID: 31553050 DOI: 10.1093/brain/awz283] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 06/10/2019] [Accepted: 07/11/2019] [Indexed: 01/17/2023] Open
Abstract
Status epilepticus is defined as a state of unrelenting seizure activity. Generalized convulsive status epilepticus is associated with a rapidly rising mortality rate, and thus constitutes a medical emergency. Benzodiazepines, which act as positive modulators of chloride (Cl-) permeable GABAA receptors, are indicated as first-line treatment, but this is ineffective in many cases. We found that 48% of children presenting with status epilepticus were unresponsive to benzodiazepine treatment, and critically, that the duration of status epilepticus at the time of treatment is an important predictor of non-responsiveness. We therefore investigated the cellular mechanisms that underlie acquired benzodiazepine resistance, using rodent organotypic and acute brain slices. Removing Mg2+ ions leads to an evolving pattern of epileptiform activity, and eventually to a persistent state of repetitive discharges that strongly resembles clinical EEG recordings of status epilepticus. We found that diazepam loses its antiseizure efficacy and conversely exacerbates epileptiform activity during this stage of status epilepticus-like activity. Interestingly, a low concentration of the barbiturate phenobarbital had a similar exacerbating effect on status epilepticus-like activity, while a high concentration of phenobarbital was effective at reducing or preventing epileptiform discharges. We then show that the persistent status epilepticus-like activity is associated with a reduction in GABAA receptor conductance and Cl- extrusion capability. We explored the effect on intraneuronal Cl- using both gramicidin, perforated-patch clamp recordings and Cl- imaging. This showed that during status epilepticus-like activity, reduced Cl- extrusion capacity was further exacerbated by activity-dependent Cl- loading, resulting in a persistently high intraneuronal Cl-. Consistent with these results, we found that optogenetic stimulation of GABAergic interneurons in the status epilepticus-like state, actually enhanced epileptiform activity in a GABAAR dependent manner. Together our findings describe a novel potential mechanism underlying benzodiazepine-resistant status epilepticus, with relevance to how this life-threatening condition should be managed in the clinic.
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Affiliation(s)
- Richard J Burman
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa.,Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa.,Department of Pharmacology, University of Oxford, Oxford, UK
| | - Joshua S Selfe
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - John Hamin Lee
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Maurits van den Berg
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Alexandru Calin
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Neela K Codadu
- Institute of Neuroscience, Medical School, Framlington Place, Newcastle upon Tyne, NE24HH, UK
| | - Rebecca Wright
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Sarah E Newey
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - R Ryley Parrish
- Institute of Neuroscience, Medical School, Framlington Place, Newcastle upon Tyne, NE24HH, UK
| | - Arieh A Katz
- Division of Medical Biochemistry, Department of Integrated Biomedical Sciences and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Jo M Wilmshurst
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Colin J Akerman
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Andrew J Trevelyan
- Institute of Neuroscience, Medical School, Framlington Place, Newcastle upon Tyne, NE24HH, UK
| | - Joseph V Raimondo
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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41
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Chizhov AV, Sanin AE. A simple model of epileptic seizure propagation: Potassium diffusion versus axo-dendritic spread. PLoS One 2020; 15:e0230787. [PMID: 32275724 PMCID: PMC7147746 DOI: 10.1371/journal.pone.0230787] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 03/08/2020] [Indexed: 12/29/2022] Open
Abstract
The mechanisms of epileptic discharge generation and spread are not yet fully known. A recently proposed simple biophysical model of interictal and ictal discharges, Epileptor-2, reproduces well the main features of neuronal excitation and ionic dynamics during discharge generation. In order to distinguish between two hypothesized mechanisms of discharge propagation, we extend the model to the case of two-dimensional propagation along the cortical neural tissue. The first mechanism is based on extracellular potassium diffusion, and the second is the propagation of spikes and postsynaptic signals along axons and dendrites. Our simulations show that potassium diffusion is too slow to reproduce an experimentally observed speed of ictal wavefront propagation (tenths of mm/s). By contrast, the synaptic mechanism predicts well the speed and synchronization of the pre-ictal bursts before the ictal front and the afterdischarges in the ictal core. Though this fact diminishes the role of diffusion and electrodiffusion, the model nevertheless highlights the role of potassium extrusion during neuronal excitation, which provides a positive feedback that changes at the ictal wavefront the balance of excitation versus inhibition in favor of excitation. This finding may help to find a target for a treatment to prevent seizure propagation.
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Affiliation(s)
- Anton V. Chizhov
- Computational Physics Laboratory, Ioffe Institute, Saint Petersburg, Russia
- Laboratory of Molecular Mechanisms of Neural Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, Saint Petersburg, Russia
- * E-mail:
| | - Aleksei E. Sanin
- Laboratory of Molecular Mechanisms of Neural Interactions, Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, Saint Petersburg, Russia
- Blue Brain Project, École polytechnique fédérale de Lausanne (EPFL), Campus Biotech, Geneva, Switzerland
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42
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Klein P, Friedman A, Hameed MQ, Kaminski RM, Bar-Klein G, Klitgaard H, Koepp M, Jozwiak S, Prince DA, Rotenberg A, Twyman R, Vezzani A, Wong M, Löscher W. Repurposed molecules for antiepileptogenesis: Missing an opportunity to prevent epilepsy? Epilepsia 2020; 61:359-386. [PMID: 32196665 PMCID: PMC8317585 DOI: 10.1111/epi.16450] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/26/2020] [Accepted: 01/27/2020] [Indexed: 12/11/2022]
Abstract
Prevention of epilepsy is a great unmet need. Acute central nervous system (CNS) insults such as traumatic brain injury (TBI), cerebrovascular accidents (CVA), and CNS infections account for 15%-20% of all epilepsy. Following TBI and CVA, there is a latency of days to years before epilepsy develops. This allows treatment to prevent or modify postinjury epilepsy. No such treatment exists. In animal models of acquired epilepsy, a number of medications in clinical use for diverse indications have been shown to have antiepileptogenic or disease-modifying effects, including medications with excellent side effect profiles. These include atorvastatin, ceftriaxone, losartan, isoflurane, N-acetylcysteine, and the antiseizure medications levetiracetam, brivaracetam, topiramate, gabapentin, pregabalin, vigabatrin, and eslicarbazepine acetate. In addition, there are preclinical antiepileptogenic data for anakinra, rapamycin, fingolimod, and erythropoietin, although these medications have potential for more serious side effects. However, except for vigabatrin, there have been almost no translation studies to prevent or modify epilepsy using these potentially "repurposable" medications. We may be missing an opportunity to develop preventive treatment for epilepsy by not evaluating these medications clinically. One reason for the lack of translation studies is that the preclinical data for most of these medications are disparate in terms of types of injury, models within different injury type, dosing, injury-treatment initiation latencies, treatment duration, and epilepsy outcome evaluation mode and duration. This makes it difficult to compare the relative strength of antiepileptogenic evidence across the molecules, and difficult to determine which drug(s) would be the best to evaluate clinically. Furthermore, most preclinical antiepileptogenic studies lack information needed for translation, such as dose-blood level relationship, brain target engagement, and dose-response, and many use treatment parameters that cannot be applied clinically, for example, treatment initiation before or at the time of injury and dosing higher than tolerated human equivalent dosing. Here, we review animal and human antiepileptogenic evidence for these medications. We highlight the gaps in our knowledge for each molecule that need to be filled in order to consider clinical translation, and we suggest a platform of preclinical antiepileptogenesis evaluation of potentially repurposable molecules or their combinations going forward.
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Affiliation(s)
- Pavel Klein
- Mid-Atlantic Epilepsy and Sleep Center, Bethesda, Maryland
| | - Alon Friedman
- Departments of Physiology and Cell Biology, and Brain and Cognitive Science, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Departments of Medical Neuroscience and Brain Repair Center, Dalhousie University, Halifax, Canada
| | - Mustafa Q. Hameed
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Rafal M. Kaminski
- Neurosymptomatic Domains Section, Roche Pharma Research & Early Development, Roche Innovation Center, Basel, Switzerland
| | - Guy Bar-Klein
- McKusick-Nathans Institute of Genetic Medicine, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Henrik Klitgaard
- Neurosciences Therapeutic Area, UCB Pharma, Braine-l’Alleud, Belgium
| | - Mathias Koepp
- Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, London, UK
| | - Sergiusz Jozwiak
- Department of Pediatric Neurology, Warsaw Medical University, Warsaw, Poland
| | - David A. Prince
- Neurology and the Neurological Sciences, Stanford University School of Medicine, Stanford, California
| | - Alexander Rotenberg
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Scientific Institute for Research and Health Care, Milan, Italy
| | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
- Center for Systems Neuroscience, Hannover, Germany
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Hameed MQ, Hsieh TH, Morales-Quezada L, Lee HHC, Damar U, MacMullin PC, Hensch TK, Rotenberg A. Ceftriaxone Treatment Preserves Cortical Inhibitory Interneuron Function via Transient Salvage of GLT-1 in a Rat Traumatic Brain Injury Model. Cereb Cortex 2019; 29:4506-4518. [PMID: 30590449 PMCID: PMC7150617 DOI: 10.1093/cercor/bhy328] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/26/2018] [Accepted: 11/28/2018] [Indexed: 12/16/2022] Open
Abstract
Traumatic brain injury (TBI) results in a decrease in glutamate transporter-1 (GLT-1) expression, the major mechanism for glutamate removal from synapses. Coupled with an increase in glutamate release from dead and dying neurons, this causes an increase in extracellular glutamate. The ensuing glutamate excitotoxicity disproportionately damages vulnerable GABAergic parvalbumin-positive inhibitory interneurons, resulting in a progressively worsening cortical excitatory:inhibitory imbalance due to a loss of GABAergic inhibitory tone, as evidenced by chronic post-traumatic symptoms such as epilepsy, and supported by neuropathologic findings. This loss of intracortical inhibition can be measured and followed noninvasively using long-interval paired-pulse transcranial magnetic stimulation with mechanomyography (LI-ppTMS-MMG). Ceftriaxone, a β-lactam antibiotic, is a potent stimulator of the expression of rodent GLT-1 and would presumably decrease excitotoxic damage to GABAergic interneurons. It may thus be a viable antiepileptogenic intervention. Using a rat fluid percussion injury TBI model, we utilized LI-ppTMS-MMG, quantitative PCR, and immunohistochemistry to test whether ceftriaxone treatment preserves intracortical inhibition and cortical parvalbumin-positive inhibitory interneuron function after TBI in rat motor cortex. We show that neocortical GLT-1 gene and protein expression are significantly reduced 1 week after TBI, and this transient loss is mitigated by ceftriaxone. Importantly, whereas intracortical inhibition declines progressively after TBI, 1 week of post-TBI ceftriaxone treatment attenuates the loss of inhibition compared to saline-treated controls. This finding is accompanied by significantly higher parvalbumin gene and protein expression in ceftriaxone-treated injured rats. Our results highlight prospects for ceftriaxone as an intervention after TBI to prevent cortical inhibitory interneuron dysfunction, partly by preserving GLT-1 expression.
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Affiliation(s)
- Mustafa Q Hameed
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurosurgery, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Tsung-Hsun Hsieh
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Physical Therapy & Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
| | - Leon Morales-Quezada
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Henry H C Lee
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Ugur Damar
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Paul C MacMullin
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Takao K Hensch
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Molecular & Cellular Biology, Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Alexander Rotenberg
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Neuromodulation Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
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Abstract
Ca2+ binding proteins (CBP) are of key importance for calcium to play its role as a pivotal second messenger. CBP bind Ca2+ in specific domains, contributing to the regulation of its concentration at the cytosol and intracellular stores. They also participate in numerous cellular functions by acting as Ca2+ transporters across cell membranes or as Ca2+-modulated sensors, i.e. decoding Ca2+ signals. Since CBP are integral to normal physiological processes, possible roles for them in a variety of diseases has attracted growing interest in recent years. In addition, research on CBP has been reinforced with advances in the structural characterization of new CBP family members. In this chapter we have updated a previous review on CBP, covering in more depth potential participation in physiopathological processes and candidacy for pharmacological targets in many diseases. We review intracellular CBP that contain the structural EF-hand domain: parvalbumin, calmodulin, S100 proteins, calcineurin and neuronal Ca2+ sensor proteins (NCS). We also address intracellular CBP lacking the EF-hand domain: annexins, CBP within intracellular Ca2+ stores (paying special attention to calreticulin and calsequestrin), proteins that contain a C2 domain (such as protein kinase C (PKC) or synaptotagmin) and other proteins of interest, such as regucalcin or proprotein convertase subtisilin kexins (PCSK). Finally, we summarise the latest findings on extracellular CBP, classified according to their Ca2+ binding structures: (i) EF-hand domains; (ii) EGF-like domains; (iii) ɣ-carboxyl glutamic acid (GLA)-rich domains; (iv) cadherin domains; (v) Ca2+-dependent (C)-type lectin-like domains; (vi) Ca2+-binding pockets of family C G-protein-coupled receptors.
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Wenzel M, Hamm JP, Peterka DS, Yuste R. Acute Focal Seizures Start As Local Synchronizations of Neuronal Ensembles. J Neurosci 2019; 39:8562-8575. [PMID: 31427393 PMCID: PMC6807279 DOI: 10.1523/jneurosci.3176-18.2019] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 07/27/2019] [Accepted: 08/09/2019] [Indexed: 11/21/2022] Open
Abstract
Understanding seizure formation and spread remains a critical goal of epilepsy research. We used fast in vivo two-photon calcium imaging in male mouse neocortex to reconstruct, with single-cell resolution, the dynamics of acute (4-aminopyridine) focal cortical seizures as they originate within a spatially confined seizure initiation site (intrafocal region), and subsequently propagate into neighboring cortical areas (extrafocal region). We find that seizures originate as local neuronal ensembles within the initiation site. This abnormal hyperactivity engages increasingly larger areas in a saltatory fashion until it breaks into neighboring cortex, where it proceeds smoothly and is then detected electrophysiologically (LFP). Interestingly, PV inhibitory interneurons have spatially heterogeneous activity in intrafocal and extrafocal territories, ruling out a simple role of inhibition in seizure formation and spread. We propose a two-step model for the progression of focal seizures, where neuronal ensembles activate first, generating a microseizure, followed by widespread neural activation in a traveling wave through neighboring cortex during macroseizures.SIGNIFICANCE STATEMENT We have used calcium imaging in mouse sensory cortex in vivo to reconstruct the onset of focal seizures elicited by local injection of the chemoconvulsant 4-aminopyridine. We demonstrate at cellular resolution that acute focal seizures originate as increasingly synchronized local neuronal ensembles. Because of its spatial confinement, this process may at first be undetectable even by nearby LFP electrodes. Further, we establish spatial footprints of local neural subtype activity that correspond to consecutive steps of seizure microprogression. Such footprints could facilitate determining the recording location (e.g., inside/outside an epileptogenic focus) in high-resolution studies, even in the absence of a priori knowledge about where exactly a seizure started.
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Affiliation(s)
- Michael Wenzel
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, New York 10027
| | - Jordan P Hamm
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, New York 10027
| | - Darcy S Peterka
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, New York 10027
| | - Rafael Yuste
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, New York 10027
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Panthi S, Leitch B. The impact of silencing feed-forward parvalbumin-expressing inhibitory interneurons in the cortico-thalamocortical network on seizure generation and behaviour. Neurobiol Dis 2019; 132:104610. [PMID: 31494287 DOI: 10.1016/j.nbd.2019.104610] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 08/10/2019] [Accepted: 09/04/2019] [Indexed: 12/14/2022] Open
Abstract
Feed-forward inhibition (FFI) is an essential mechanism within the brain, to regulate neuronal firing and prevent runaway excitation. In the cortico-thalamocortical (CTC) network, fast spiking parvalbumin-expressing (PV+) inhibitory interneurons regulate the firing of pyramidal cells in the cortex and relay neurons in the thalamus. PV+ interneuron dysfunction has been implicated in several neurological disorders, including epilepsy. Previously, we demonstrated that loss of excitatory AMPA-receptors, specifically at synapses on PV+ interneurons in CTC feedforward microcircuits, occurs in the stargazer mouse model of absence epilepsy. These mice present with absence seizures characterized by spike and wave discharges (SWDs) on electroencephalogram (EEG) and concomitant behavioural arrest, similar to childhood absence epilepsy. The aim of the current study was to investigate the impact of loss of FFI within the CTC on absence seizure generation and behaviour using new Designer Receptor Exclusively Activated by Designer Drug (DREADD) technology. We crossed PV-Cre mice with Cre-dependent hM4Di DREADD strains of mice, which allowed Cre-recombinase-mediated restricted expression of inhibitory Gi-DREADDs in PV+ interneurons. We then tested the impact of global and focal (within the CTC network) silencing of PV+ interneurons. CNO mediated silencing of all PV+ interneurons by intraperitoneal injection caused the impairment of motor control, decreased locomotion and increased anxiety in a dose-dependent manner. Such silencing generated pathological oscillations similar to absence-like seizures. Focal silencing of PV+ interneurons within cortical or thalamic feedforward microcircuits, induced SWD-like oscillations and associated behavioural arrest. Epileptiform activity on EEG appeared significantly sooner after focal injection compared to peripheral injection of CNO. However, the mean duration of each oscillatory burst and spike frequency was similar, irrespective of mode of CNO delivery. No significant changes were observed in vehicle-treated or non-DREADD wild-type control animals. These data suggest that dysfunctional feed-forward inhibition in CTC microcircuits may be an important target for future therapy strategies for some patients with absence seizures. Additionally, silencing of PV+ interneurons in other brain regions may contribute to anxiety related neurological and psychiatric disorders.
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Affiliation(s)
- Sandesh Panthi
- Department of Anatomy, School of Biomedical Sciences, and Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Beulah Leitch
- Department of Anatomy, School of Biomedical Sciences, and Brain Health Research Centre, University of Otago, Dunedin, New Zealand.
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Tryba AK, Merricks EM, Lee S, Pham T, Cho S, Nordli DR, Eissa TL, Goodman RR, McKhann GM, Emerson RG, Schevon CA, van Drongelen W. Role of paroxysmal depolarization in focal seizure activity. J Neurophysiol 2019; 122:1861-1873. [PMID: 31461373 DOI: 10.1152/jn.00392.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We analyze the role of inhibition in sustaining focal epileptic seizure activity. We review ongoing seizure activity at the mesoscopic scale that can be observed with microelectrode arrays as well as at the macroscale of standard clinical EEG. We provide clinical, experimental, and modeling data to support the hypothesis that paroxysmal depolarization (PD) is a critical component of the ictal machinery. We present dual-patch recordings in cortical cultures showing reduced synaptic transmission associated with presynaptic occurrence of PD, and we find that the PD threshold is cell size related. We further find evidence that optically evoked PD activity in parvalbumin neurons can promote propagation of neuronal excitation in neocortical networks in vitro. Spike sorting results from microelectrode array measurements around ictal wave propagation in human focal seizures demonstrate a strong increase in putative inhibitory firing with an approaching excitatory wave, followed by a sudden reduction of firing at passage. At the macroscopic level, we summarize evidence that this excitatory ictal wave activity is strongly correlated with oscillatory activity across a centimeter-sized cortical network. We summarize Wilson-Cowan-type modeling showing how inhibitory function is crucial for this behavior. Our findings motivated us to develop a network motif of neurons in silico, governed by a reduced version of the Hodgkin-Huxley formalism, to show how feedforward, feedback, PD, and local failure of inhibition contribute to observed dynamics across network scales. The presented multidisciplinary evidence suggests that the PD not only is a cellular marker or epiphenomenon but actively contributes to seizure activity.NEW & NOTEWORTHY We present mechanisms of ongoing focal seizures across meso- and macroscales of microelectrode array and standard clinical recordings, respectively. We find modeling, experimental, and clinical evidence for a dual role of inhibition across these scales: local failure of inhibition allows propagation of a mesoscopic ictal wave, whereas inhibition elsewhere remains intact and sustains macroscopic oscillatory activity. We present evidence for paroxysmal depolarization as a mechanism behind this dual role of inhibition in shaping ictal activity.
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Affiliation(s)
- Andrew K Tryba
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
| | - Edward M Merricks
- Department of Neurology, Columbia University Medical Center, New York, New York
| | - Somin Lee
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
| | - Tuan Pham
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
| | - SungJun Cho
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
| | - Douglas R Nordli
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
| | - Tahra L Eissa
- Department of Applied Mathematics, University of Colorado Boulder, Boulder, Colorado
| | - Robert R Goodman
- Department of Neurosurgery, Northwell Health/Lenox Hill Hospital, New York, New York
| | - Guy M McKhann
- Department of Neurological Surgery, Columbia University Medical Center, New York, New York
| | | | - Catherine A Schevon
- Department of Neurology, Columbia University Medical Center, New York, New York
| | - Wim van Drongelen
- Section of Neurology, Department of Pediatrics, The University of Chicago, Chicago, Illinois
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48
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Liou JY, Ma H, Wenzel M, Zhao M, Baird-Daniel E, Smith EH, Daniel A, Emerson R, Yuste R, Schwartz TH, Schevon CA. Role of inhibitory control in modulating focal seizure spread. Brain 2019; 141:2083-2097. [PMID: 29757347 DOI: 10.1093/brain/awy116] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Accepted: 03/04/2018] [Indexed: 11/12/2022] Open
Abstract
Focal seizure propagation is classically thought to be spatially contiguous. However, distribution of seizures through a large-scale epileptic network has been theorized. Here, we used a multielectrode array, wide field calcium imaging, and two-photon calcium imaging to study focal seizure propagation pathways in an acute rodent neocortical 4-aminopyridine model. Although ictal neuronal bursts did not propagate beyond a 2-3-mm region, they were associated with hemisphere-wide field potential fluctuations and parvalbumin-positive interneuron activity outside the seizure focus. While bicuculline surface application enhanced contiguous seizure propagation, focal bicuculline microinjection at sites distant to the 4-aminopyridine focus resulted in epileptic network formation with maximal activity at the two foci. Our study suggests that both classical and epileptic network propagation can arise from localized inhibition defects, and that the network appearance can arise in the context of normal brain structure without requirement for pathological connectivity changes between sites.
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Affiliation(s)
- Jyun-You Liou
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, USA
| | - Hongtao Ma
- Department of Neurological Surgery, Feil Family Brain and Mind Research Institute, Sackler Brain and Spine Institute, Weill Cornell Medical College, New York, NY, USA
| | - Michael Wenzel
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, NY, USA; Department of Neuroscience, Columbia University, New York, NY, USA
| | - Mingrui Zhao
- Department of Neurological Surgery, Feil Family Brain and Mind Research Institute, Sackler Brain and Spine Institute, Weill Cornell Medical College, New York, NY, USA
| | - Eliza Baird-Daniel
- Department of Neurological Surgery, Feil Family Brain and Mind Research Institute, Sackler Brain and Spine Institute, Weill Cornell Medical College, New York, NY, USA
| | - Elliot H Smith
- Department of Neurological Surgery, Columbia University Medical Center, New York, NY, USA
| | - Andy Daniel
- Department of Neurological Surgery, Feil Family Brain and Mind Research Institute, Sackler Brain and Spine Institute, Weill Cornell Medical College, New York, NY, USA
| | - Ronald Emerson
- Hospital for Special Surgery, Weill Cornell Medical College, 535 East 70th Street, New York, NY, USA
| | - Rafael Yuste
- Neurotechnology Center, Department of Biological Sciences, Columbia University, New York, NY, USA; Department of Neuroscience, Columbia University, New York, NY, USA
| | - Theodore H Schwartz
- Department of Neurological Surgery, Feil Family Brain and Mind Research Institute, Sackler Brain and Spine Institute, Weill Cornell Medical College, New York, NY, USA
| | - Catherine A Schevon
- Department of Neurology, Columbia University Medical Center, New York, New York, USA
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49
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Chen G, Zhang Y, Li X, Zhao X, Ye Q, Lin Y, Tao HW, Rasch MJ, Zhang X. Distinct Inhibitory Circuits Orchestrate Cortical beta and gamma Band Oscillations. Neuron 2019; 96:1403-1418.e6. [PMID: 29268099 DOI: 10.1016/j.neuron.2017.11.033] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 09/25/2017] [Accepted: 11/20/2017] [Indexed: 12/29/2022]
Abstract
Distinct subtypes of inhibitory interneuron are known to shape diverse rhythmic activities in the cortex, but how they interact to orchestrate specific band activity remains largely unknown. By recording optogenetically tagged interneurons of specific subtypes in the primary visual cortex of behaving mice, we show that spiking of somatostatin (SOM)- and parvalbumin (PV)-expressing interneurons preferentially correlates with cortical beta and gamma band oscillations, respectively. Suppression of SOM cell spiking reduces the spontaneous low-frequency band (<30-Hz) oscillations and selectively reduces visually induced enhancement of beta oscillation. In comparison, suppressing PV cell activity elevates the synchronization of spontaneous activity across a broad frequency range and further precludes visually induced changes in beta and gamma oscillations. Rhythmic activation of SOM and PV cells in the local circuit entrains resonant activity in the narrow 5- to 30-Hz band and the wide 20- to 80-Hz band, respectively. Together, these findings reveal differential and cooperative roles of SOM and PV inhibitory neurons in orchestrating specific cortical oscillations.
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Affiliation(s)
- Guang Chen
- State Key Laboratory of Cognitive Neuroscience & Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; Institute of Neuroscience, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yuan Zhang
- State Key Laboratory of Cognitive Neuroscience & Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Xiang Li
- State Key Laboratory of Cognitive Neuroscience & Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Xiaochen Zhao
- State Key Laboratory of Cognitive Neuroscience & Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Qian Ye
- State Key Laboratory of Cognitive Neuroscience & Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Yingxi Lin
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Huizhong W Tao
- Zilkha Neurogenetic Institute, Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | - Malte J Rasch
- State Key Laboratory of Cognitive Neuroscience & Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China.
| | - Xiaohui Zhang
- State Key Laboratory of Cognitive Neuroscience & Learning, IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China.
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50
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de Curtis M, Librizzi L, Uva L, Gnatkovsky V. GABAA receptor-mediated networks during focal seizure onset and progression in vitro. Neurobiol Dis 2019; 125:190-197. [DOI: 10.1016/j.nbd.2019.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 01/08/2019] [Accepted: 02/07/2019] [Indexed: 02/02/2023] Open
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