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Chvojka J, Kudláček J, Liska K, Pant A, Jefferys JG, Jiruska P. Dissociation Between the Epileptogenic Lesion and Primary Seizure Onset Zone in the Tetanus Toxin Model of Temporal Lobe Epilepsy. Physiol Res 2024; 73:435-447. [PMID: 39027960 DOI: 10.33549/physiolres.935281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024] Open
Abstract
Despite extensive temporal lobe epilepsy (TLE) research, understanding the specific limbic structures' roles in seizures remains limited. This weakness can be attributed to the complex nature of TLE and the existence of various TLE subsyndromes, including non-lesional TLE. Conventional TLE models like kainate and pilocarpine hinder precise assessment of the role of individual limbic structures in TLE ictogenesis due to widespread limbic damage induced by the initial status epilepticus. In this study, we used a non-lesional TLE model characterized by the absence of initial status and cell damage to determine the spatiotemporal profile of seizure initiation and limbic structure recruitment in TLE. Epilepsy was induced by injecting a minute dose of tetanus toxin into the right dorsal hippocampus in seven animals. Following injection, animals were implanted with bipolar recording electrodes in the amygdala, dorsal hippocampus, ventral hippocampus, piriform, perirhinal, and entorhinal cortices of both hemispheres. The animals were video-EEG monitored for four weeks. In total, 140 seizures (20 seizures per animal) were analyzed. The average duration of each seizure was 53.2+/-3.9 s. Seizure could initiate in any limbic structure. Most seizures initiated in the ipsilateral (41 %) and contralateral (18 %) ventral hippocampi. These two structures displayed a significantly higher probability of seizure initiation than by chance. The involvement of limbic structures in seizure initiation varied between individual animals. Surprisingly, only 7 % of seizures initiated in the injected dorsal hippocampus. The limbic structure recruitment into the seizure activity wasn't random and displayed consistent patterns of early recruitment of hippocampi and entorhinal cortices. Although ventral hippocampus represented the primary seizure onset zone, the study demonstrated the involvement of multiple limbic structures in seizure initiation in a non-lesional TLE model. The study also revealed the dichotomy between the primary epileptogenic lesion and main seizure onset zones and points to the central role of ventral hippocampi in temporal lobe ictogenesis.
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Affiliation(s)
- J Chvojka
- Department of Physiology, Second Faculty of Medicine, Charles University, Prague 5, Czech Republic. or
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Postnikova TY, Diespirov GP, Malkin SL, Chernyshev AS, Vylekzhanina EN, Zaitsev AV. Morphological and Functional Alterations in the CA1 Pyramidal Neurons of the Rat Hippocampus in the Chronic Phase of the Lithium-Pilocarpine Model of Epilepsy. Int J Mol Sci 2024; 25:7568. [PMID: 39062811 PMCID: PMC11276980 DOI: 10.3390/ijms25147568] [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: 06/20/2024] [Revised: 07/03/2024] [Accepted: 07/09/2024] [Indexed: 07/28/2024] Open
Abstract
Epilepsy is known to cause alterations in neural networks. However, many details of these changes remain poorly understood. The objective of this study was to investigate changes in the properties of hippocampal CA1 pyramidal neurons and their synaptic inputs in a rat lithium-pilocarpine model of epilepsy. In the chronic phase of the model, we found a marked loss of pyramidal neurons in the CA1 area. However, the membrane properties of the neurons remained essentially unaltered. The results of the electrophysiological and morphological studies indicate that the direct pathway from the entorhinal cortex to CA1 neurons is reinforced in epileptic animals, whereas the inputs to them from CA3 are either unaltered or even diminished. In particular, the dendritic spine density in the str. lacunosum moleculare, where the direct pathway from the entorhinal cortex terminates, was found to be 2.5 times higher in epileptic rats than in control rats. Furthermore, the summation of responses upon stimulation of the temporoammonic pathway was enhanced by approximately twofold in epileptic rats. This enhancement is believed to be a significant contributing factor to the heightened epileptic activity observed in the entorhinal cortex of epileptic rats using an ex vivo 4-aminopyridine model.
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Affiliation(s)
- Tatyana Y. Postnikova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia; (T.Y.P.); (G.P.D.); (S.L.M.); (E.N.V.)
| | - Georgy P. Diespirov
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia; (T.Y.P.); (G.P.D.); (S.L.M.); (E.N.V.)
| | - Sergey L. Malkin
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia; (T.Y.P.); (G.P.D.); (S.L.M.); (E.N.V.)
| | | | - Elizaveta N. Vylekzhanina
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia; (T.Y.P.); (G.P.D.); (S.L.M.); (E.N.V.)
| | - Aleksey V. Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia; (T.Y.P.); (G.P.D.); (S.L.M.); (E.N.V.)
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Trofimova AM, Amakhin DV, Postnikova TY, Tiselko VS, Alekseev A, Podoliak E, Gordeliy VI, Chizhov AV, Zaitsev AV. Light-Driven Sodium Pump as a Potential Tool for the Control of Seizures in Epilepsy. Mol Neurobiol 2024; 61:4691-4704. [PMID: 38114761 DOI: 10.1007/s12035-023-03865-z] [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: 08/12/2023] [Accepted: 12/06/2023] [Indexed: 12/21/2023]
Abstract
The marine flavobacterium Krokinobactereikastus light-driven sodium pump (KR2) generates an outward sodium ion current under 530 nm light stimulation, representing a promising optogenetic tool for seizure control. However, the specifics of KR2 application to suppress epileptic activity have not yet been addressed. In the present study, we investigated the possibility of KR2 photostimulation to suppress epileptiform activity in mouse brain slices using the 4-aminopyrindine (4-AP) model. We injected the adeno-associated viral vector (AAV-PHP.eB-hSyn-KR2-YFP) containing the KR2 sodium pump gene enhanced with appropriate trafficking tags. KR2 expression was observed in the lateral entorhinal cortex and CA1 hippocampus. Using whole-cell patch clamp in mouse brain slices, we show that KR2, when stimulated with LED light, induces a substantial hyperpolarization of entorhinal neurons. However, continuous photostimulation of KR2 does not interrupt ictal discharges in mouse entorhinal cortex slices induced by a solution containing 4-AP. KR2-induced hyperpolarization strongly activates neuronal HCN channels. Consequently, turning off photostimulation resulted in HCN channel-mediated rebound depolarization accompanied by a transient increase in spontaneous network activity. Using low-frequency pulsed photostimulation, we induced the generation of short HCN channel-mediated discharges that occurred in response to the light stimulus being turned off; these discharges reliably interrupt ictal activity. Thus, low-frequency pulsed photostimulation of KR2 can be considered as a potential tool for controlling epileptic seizures.
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Affiliation(s)
- Alina M Trofimova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia
| | - Dmitry V Amakhin
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia
| | - Tatyana Y Postnikova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia
| | - Vasilii S Tiselko
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia
| | - Alexey Alekseev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Elizaveta Podoliak
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
- Department of Ophthalmology, Universitäts-Augenklinik Bonn, University of Bonn, Bonn, Germany
| | - Valentin I Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Anton V Chizhov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia
- MathNeuro Team, Inria Centre at Université Côte d'Azur, Sophia Antipolis, France
| | - Aleksey V Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russia.
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Dossi E, Zonca L, Pivonkova H, Milior G, Moulard J, Vargova L, Chever O, Holcman D, Rouach N. Astroglial gap junctions strengthen hippocampal network activity by sustaining afterhyperpolarization via KCNQ channels. Cell Rep 2024; 43:114158. [PMID: 38722742 DOI: 10.1016/j.celrep.2024.114158] [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: 12/15/2023] [Revised: 03/01/2024] [Accepted: 04/11/2024] [Indexed: 06/01/2024] Open
Abstract
Throughout the brain, astrocytes form networks mediated by gap junction channels that promote the activity of neuronal ensembles. Although their inputs on neuronal information processing are well established, how molecular gap junction channels shape neuronal network patterns remains unclear. Here, using astroglial connexin-deficient mice, in which astrocytes are disconnected and neuronal bursting patterns are abnormal, we show that astrocyte networks strengthen bursting activity via dynamic regulation of extracellular potassium levels, independently of glutamate homeostasis or metabolic support. Using a facilitation-depression model, we identify neuronal afterhyperpolarization as the key parameter underlying bursting pattern regulation by extracellular potassium in mice with disconnected astrocytes. We confirm this prediction experimentally and reveal that astroglial network control of extracellular potassium sustains neuronal afterhyperpolarization via KCNQ voltage-gated K+ channels. Altogether, these data delineate how astroglial gap junctions mechanistically strengthen neuronal population bursts and point to approaches for controlling aberrant activity in neurological diseases.
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Affiliation(s)
- Elena Dossi
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Labex Memolife, Université PSL, Paris, France
| | - Lou Zonca
- Group of Data Modeling and Computational Biology, Institute of Biology, Ecole Normale Superieure, CNRS, INSERM, Université PSL, Paris, France; ED386, Ecole Doctorale de Sciences Mathématiques Paris Centre, Paris, France
| | - Helena Pivonkova
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Labex Memolife, Université PSL, Paris, France; Department of Cellular Neurophysiology, Institute of Experimental Medicine, Czech Academy of Sciences, Prague, Czech Republic; 2(nd) Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Giampaolo Milior
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Labex Memolife, Université PSL, Paris, France
| | - Julien Moulard
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Labex Memolife, Université PSL, Paris, France
| | - Lydia Vargova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Czech Academy of Sciences, Prague, Czech Republic; 2(nd) Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Oana Chever
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Labex Memolife, Université PSL, Paris, France
| | - David Holcman
- Group of Data Modeling and Computational Biology, Institute of Biology, Ecole Normale Superieure, CNRS, INSERM, Université PSL, Paris, France.
| | - Nathalie Rouach
- Neuroglial Interactions in Cerebral Physiology and Pathologies, Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Labex Memolife, Université PSL, Paris, France.
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Zinchenko VP, Teplov IY, Kosenkov AM, Gaidin SG, Kairat BK, Tuleukhanov ST. Participation of calcium-permeable AMPA receptors in the regulation of epileptiform activity of hippocampal neurons. Front Synaptic Neurosci 2024; 16:1349984. [PMID: 38577639 PMCID: PMC10987725 DOI: 10.3389/fnsyn.2024.1349984] [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: 12/05/2023] [Accepted: 02/20/2024] [Indexed: 04/06/2024] Open
Abstract
Introduction Epileptiform activity is the most striking result of hyperexcitation of a group of neurons that can occur in different brain regions and then spread to other sites. Later it was shown that these rhythms have a cellular correlate in vitro called paroxysmal depolarization shift (PDS). In 13-15 DIV neuron-glial cell culture, inhibition of the GABA(A) receptors induces bursts of action potential in the form of clasters PDS and oscillations of intracellular Ca2+ concentration ([Ca2+]i). We demonstrate that GABAergic neurons expressing calcium-permeable AMPA receptors (CP-AMPARs) as well as Kv7-type potassium channels regulate hippocampal glutamatergic neurons' excitability during epileptiform activity in culture. Methods A combination of whole-cell patch-clamp in current clamp mode and calcium imaging microscopy was used to simultaneously register membrane potential and [Ca2+]i level. To identify GABAergic cell cultures were fixed and stained with antibodies against glutamate decarboxylase GAD 65/67 and neuron-specific enolase (NSE) after vital [Ca2+]i imaging. Results and discussion It was shown that CP-AMPARs are involved in the regulation of the PDS clusters and [Ca2+]i pulses accompanied them. Activation of CP-AMPARs of GABAergic neurons is thought to cause the release of GABA, which activates the GABA(B) receptors of other GABAergic interneurons. It is assumed that activation of these GABA(B) receptors leads to the release of beta-gamma subunits of Gi protein, which activate potassium channels, resulting in hyperpolarization and inhibition of these interneurons. The latter causes disinhibition of glutamatergic neurons, the targets of these interneurons. In turn, the CP-AMPAR antagonist, NASPM, has the opposite effect. Measurement of membrane potential in GABAergic neurons by the patch-clamp method in whole-cell configuration demonstrated that NASPM suppresses hyperpolarization in clusters and individual PDSs. It is believed that Kv7-type potassium channels are involved in the control of hyperpolarization during epileptiform activity. The blocker of Kv7 channels, XE 991, mimicked the effect of the CP-AMPARs antagonist on PDS clusters. Both drugs increased the duration of the PDS cluster. In turn, the Kv7 activator, retigabine, decreased the duration of the PDS cluster and Ca2+ pulse. In addition, retigabine led to deep posthyperpolarization at the end of the PDS cluster. The Kv7 channel is believed to be involved in the formation of PDS, as the channel blocker reduced the rate of hyperpolarization in the PDS almost three times. Thus, GABAergic neurons expressing CP-AMPARs, regulate the membrane potential of innervated glutamatergic neurons by modulating the activity of postsynaptic potassium channels of other GABAergic neurons.
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Affiliation(s)
- Valery Petrovich Zinchenko
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Russia
| | - Ilia Yu. Teplov
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Russia
| | - Artem Mikhailovich Kosenkov
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Russia
| | - Sergei Gennadievich Gaidin
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Russia
| | - Bakytzhan Kairatuly Kairat
- Laboratory of Biophysics, Chronobiology and Biomedicine, Faculty of Biology and Biotechnology, Al-Farabi Kazakh National University, Almaty, Kazakhstan
| | - Sultan Tuleukhanovich Tuleukhanov
- Laboratory of Biophysics, Chronobiology and Biomedicine, Faculty of Biology and Biotechnology, Al-Farabi Kazakh National University, Almaty, Kazakhstan
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Zhao C, Rollo B, Shahid Javaid M, Huang Z, He W, Xu H, Kwan P, Zhang C. An integrated in vitro human iPSCs-derived neuron and in vivo animal approach for preclinical screening of anti-seizure compounds. J Adv Res 2023:S2090-1232(23)00361-2. [PMID: 37995945 DOI: 10.1016/j.jare.2023.11.022] [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: 09/04/2023] [Revised: 11/15/2023] [Accepted: 11/19/2023] [Indexed: 11/25/2023] Open
Abstract
INTRODUCTION One-third of people with epilepsy continue to experience seizures despite treatment with existing anti-seizure medications (ASMs). The failure of modern ASMs to substantially improve epilepsy prognosis has been partly attributed to overreliance on acute rodent models in preclinical drug development as they do not adequately recapitulate the mechanisms of human epilepsy, are labor-intensive and unsuitable for high-throughput screening (HTS). There is an urgent need to find human-relevant HTS models in preclinical drug development to identify novel anti-seizure compounds. OBJECTIVES This paper developed high-throughput preclinical screening models to identify new ASMs. METHODS 14 natural compounds (α-asarone, curcumin, vinpocetine, magnolol, ligustrazine, osthole, tanshinone IIA, piperine, gastrodin, quercetin, berberine, chrysin, schizandrin A and resveratrol) were assessed for their ability to suppress epileptiform activity as measured by multi-electrode arrays (MEA) in neural cultures derived from human induced pluripotent stem cells (iPSCs). In parallel, they were tested for anti-seizure effects in zebrafish and mouse models, which have been widely used in development of modern ASMs. The effects of the compounds in these models were compared. Two approved ASMs were used as positive controls. RESULTS Epileptiform activity could be induced in iPSCs-derived neurons following treatment with 4-aminopyridine (4-AP) and inhibited by standard ASMs, carbamazepine, and phenytoin. Eight of the 14 natural compounds significantly inhibited the epileptiform activity in iPSCs-derived neurons. Among them, piperine, magnolol, α-asarone, and osthole showed significant anti-seizure effects both in zebrafish and mice. Comparative analysis showed that compounds ineffective in the iPSCs-derived neural model also showed no anti-seizure effects in the zebrafish or mouse models. CONCLUSION Our findings support the use of iPSCs-derived human neurons for first-line high-throughput screening to identify compounds with anti-seizure properties and exclude ineffective compounds. Effective compounds may then be selected for animal evaluation before clinical testing. This integrated approach may improve the efficiency of developing novel ASMs.
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Affiliation(s)
- Chunfang Zhao
- Department of Pathology and Institute of Molecular Pathology, The First Affiliated Hospital of Nanchang University, School of Pharmacy, Nanchang University, Nanchang, Jiangxi 330006, China
| | - Ben Rollo
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne 3004, Australia
| | - Muhammad Shahid Javaid
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne 3004, Australia
| | - Ziyu Huang
- Department of Pathology and Institute of Molecular Pathology, The First Affiliated Hospital of Nanchang University, School of Pharmacy, Nanchang University, Nanchang, Jiangxi 330006, China
| | - Wen He
- Department of Pathology and Institute of Molecular Pathology, The First Affiliated Hospital of Nanchang University, School of Pharmacy, Nanchang University, Nanchang, Jiangxi 330006, China
| | - Hong Xu
- Institute of Life Science, Nanchang University, Nanchang 330031, China
| | - Patrick Kwan
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne 3004, Australia; Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, China; Departments of Neurology and Medicine, University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia.
| | - Chunbo Zhang
- Department of Pathology and Institute of Molecular Pathology, The First Affiliated Hospital of Nanchang University, School of Pharmacy, Nanchang University, Nanchang, Jiangxi 330006, China.
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Hannan S, Thomas J, Jaber K, El Kosseifi C, Ho A, Abdallah C, Avigdor T, Gotman J, Frauscher B. The Differing Effects of Sleep on Ictal and Interictal Network Dynamics in Drug-Resistant Epilepsy. Ann Neurol 2023. [PMID: 37712215 DOI: 10.1002/ana.26796] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 07/14/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023]
Abstract
OBJECTIVE Sleep has important influences on focal interictal epileptiform discharges (IEDs), and the rates and spatial extent of IEDs are increased in non-rapid eye movement (NREM) sleep. In contrast, the influence of sleep on seizures is less clear, and its effects on seizure topography are poorly documented. We evaluated the influences of NREM sleep on ictal spatiotemporal dynamics and contrasted these with interictal network dynamics. METHODS We included patients with drug-resistant focal epilepsy who underwent continuous intracranial electroencephalography (iEEG) with depth electrodes. Patients were selected if they had 1 to 3 seizures from each vigilance state, wakefulness and NREM sleep, within a 48-hour window, and under the same antiseizure medication. A 10-minute epoch of the interictal iEEG was selected per state, and IEDs were detected automatically. A total of 25 patients (13 women; aged 32.5 ± 7.1 years) were included. RESULTS The seizure onset pattern, duration, spatiotemporal propagation, and latency of ictal high-frequency activity did not differ significantly between wakefulness and NREM sleep (all p > 0.05). In contrast, IED rates and spatial distribution were increased in NREM compared with wakefulness (p < 0.001, Cliff's d = 0.48 and 0.49). The spatial overlap between vigilance states was higher for seizures (57.1 ± 40.1%) than IEDs (41.7 ± 46.2%; p = 0.001, Cliff's d = 0.51). INTERPRETATION In contrast to its effects on IEDs, NREM sleep does not affect ictal spatiotemporal dynamics. This suggests that once the brain surpasses the seizure threshold, it will follow the underlying epileptic network irrespective of the vigilance state. These findings offer valuable insights into neural network dynamics in epilepsy and have important clinical implications for localizing seizure foci. ANN NEUROL 2023.
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Affiliation(s)
- Sana Hannan
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, McGill University, Montréal, Quebec, Canada
- Department of Biomedical and Life Sciences, Lancaster University, Lancaster, United Kingdom
| | - John Thomas
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, McGill University, Montréal, Quebec, Canada
| | - Kassem Jaber
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, McGill University, Montréal, Quebec, Canada
| | - Charbel El Kosseifi
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, McGill University, Montréal, Quebec, Canada
| | - Alyssa Ho
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, McGill University, Montréal, Quebec, Canada
| | - Chifaou Abdallah
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, McGill University, Montréal, Quebec, Canada
| | - Tamir Avigdor
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, McGill University, Montréal, Quebec, Canada
| | - Jean Gotman
- Montreal Neurological Institute and Hospital, McGill University, Montréal, Quebec, Canada
| | - Birgit Frauscher
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, McGill University, Montréal, Quebec, Canada
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
- Analytical Neurophysiology Lab, Duke University Medical Center, Durham, North Carolina, USA
- Department of Biomedical Engineering, Duke Pratt School of Engineering, Durham, North Carolina, USA
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Postnikova TY, Griflyuk AV, Zhigulin AS, Soboleva EB, Barygin OI, Amakhin DV, Zaitsev AV. Febrile Seizures Cause a Rapid Depletion of Calcium-Permeable AMPA Receptors at the Synapses of Principal Neurons in the Entorhinal Cortex and Hippocampus of the Rat. Int J Mol Sci 2023; 24:12621. [PMID: 37628802 PMCID: PMC10454714 DOI: 10.3390/ijms241612621] [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: 07/09/2023] [Revised: 08/01/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Febrile seizures (FSs) are a relatively common early-life condition that can cause CNS developmental disorders, but the specific mechanisms of action of FS are poorly understood. In this work, we used hyperthermia-induced FS in 10-day-old rats. We demonstrated that the efficiency of glutamatergic synaptic transmission decreased rapidly after FS by recording local field potentials. This effect was transient, and after two days there were no differences between control and post-FS groups. During early ontogeny, the proportion of calcium-permeable (CP)-AMPA receptors in the synapses of the principal cortical and hippocampal neurons is high. Therefore, rapid internalization of CP-AMPA receptors may be one of the mechanisms underlying this phenomenon. Using the whole-cell patch-clamp method and the selective CP-AMPA receptor blocker IEM-1460, we tested whether the proportion of CP-AMPA receptors changed. We have demonstrated that FS rapidly reduces synaptic CP-AMPA receptors in both the hippocampus and the entorhinal cortex. This process was accompanied by a sharp decrease in the calcium permeability of the membrane of principal neurons, which we revealed in experiments with kainate-induced cobalt uptake. Our experiments show that FSs cause rapid changes in the function of the glutamatergic system, which may have compensatory effects that prevent excessive excitotoxicity and neuronal death.
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Affiliation(s)
| | | | | | | | | | | | - Aleksey V. Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, 44, Toreza Prospekt, Saint Petersburg 194223, Russia; (T.Y.P.); (A.V.G.); (A.S.Z.); (E.B.S.); (O.I.B.); (D.V.A.)
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Topczewska A, Giacalone E, Pratt WS, Migliore M, Dolphin AC, Shah MM. T-type Ca 2+ and persistent Na + currents synergistically elevate ventral, not dorsal, entorhinal cortical stellate cell excitability. Cell Rep 2023; 42:112699. [PMID: 37368752 PMCID: PMC10687207 DOI: 10.1016/j.celrep.2023.112699] [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: 03/24/2022] [Revised: 03/08/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Dorsal and ventral medial entorhinal cortex (mEC) regions have distinct neural network firing patterns to differentially support functions such as spatial memory. Accordingly, mEC layer II dorsal stellate neurons are less excitable than ventral neurons. This is partly because the densities of inhibitory conductances are higher in dorsal than ventral neurons. Here, we report that T-type Ca2+ currents increase 3-fold along the dorsal-ventral axis in mEC layer II stellate neurons, with twice as much CaV3.2 mRNA in ventral mEC compared with dorsal mEC. Long depolarizing stimuli trigger T-type Ca2+ currents, which interact with persistent Na+ currents to elevate the membrane voltage and spike firing in ventral, not dorsal, neurons. T-type Ca2+ currents themselves prolong excitatory postsynaptic potentials (EPSPs) to enhance their summation and spike coupling in ventral neurons only. These findings indicate that T-type Ca2+ currents critically influence the dorsal-ventral mEC stellate neuron excitability gradient and, thereby, mEC dorsal-ventral circuit activity.
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Affiliation(s)
| | | | - Wendy S Pratt
- Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Michele Migliore
- Institute of Biophysics, National Research Council, 90146 Palermo, Italy
| | - Annette C Dolphin
- Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Mala M Shah
- Pharmacology, School of Pharmacy, University College London, London WC1N 4AX, UK.
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Benny F, Kumar S, Binu A, Parambi DGT, Alsahli TG, Al-Sehemi AG, Chandran N, Manisha DS, Sreekumar S, Bhatt A, Madhu K, Mathew B. Targeting GABA receptors with chalcone derivative compounds, what is the evidence? Expert Opin Ther Targets 2023; 27:1257-1269. [PMID: 38112471 DOI: 10.1080/14728222.2023.2293752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 12/08/2023] [Indexed: 12/21/2023]
Abstract
INTRODUCTION In medicinal chemistry, privileged structures have been frequently exploited as a successful template for drug discovery. Common simple scaffolds like chalcone are present in a wide range of naturally occurring chemicals. Chalcone exhibits extensive biological activity and has drawn attention in this context due to its function in the GABA receptor. Epilepsy and GABA receptors are related. It is a chronic neurological condition that affects globally. AREAS COVERED Numerous neurological disorders, including anxiety and epilepsy, have been related to GABA, the brain's most prevalent inhibitory neurotransmitter. We go through the role of GABA receptors in anxiety and epilepsy in this review. The structure-activity relationship of chalcone and its derivatives on the GABA receptor is covered in our final section. EXPERT OPINION GABA is a potential therapeutic target for issues associated with the nervous system. We talk about the potential effects of chalcone as a treatment for epilepsy and anxiety on the GABA receptor. Therefore, thorough research is necessary in this regard; the value of in silico tools in developing and enhancing GABA agonists is significant.
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Affiliation(s)
- Feba Benny
- Department of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi, India
| | - Sunil Kumar
- Department of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi, India
| | - Aiswarya Binu
- Department of Pharmacology, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi, India
| | - Della Grace Thomas Parambi
- College of Pharmacy, Department of Pharmaceutical Chemistry, Jouf university, Sakaka, Al Jouf, Saudi Arabia
| | - Tariq G Alsahli
- College of Pharmacy, Department of Pharmacology, Jouf university, Sakaka, Al Jouf, Saudi Arabia
| | - Abdullah G Al-Sehemi
- Research Center for Advanced Materials Science (RCAMS), King Khalid University, Abha, Saudi Arabia
- Department of Chemistry, College of Science, King Khalid University, Abha, Saudi Arabia
| | - Namitha Chandran
- Department of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi, India
| | - Deepthi S Manisha
- Department of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi, India
| | - Sarath Sreekumar
- Department of Pharmacology, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi, India
| | - Akanksha Bhatt
- School of Pharmacy, Graphic Era Hill University, Dehradun, Uttarakhand, India
| | - Krishnadas Madhu
- Department of Pharmacology, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi, India
| | - Bijo Mathew
- Department of Pharmaceutical Chemistry, Amrita School of Pharmacy, Amrita Vishwa Vidyapeetham, AIMS Health Sciences Campus, Kochi, India
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11
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Cota VR, Cançado SAV, Moraes MFD. On temporal scale-free non-periodic stimulation and its mechanisms as an infinite improbability drive of the brain's functional connectogram. Front Neuroinform 2023; 17:1173597. [PMID: 37293579 PMCID: PMC10244597 DOI: 10.3389/fninf.2023.1173597] [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: 02/24/2023] [Accepted: 05/02/2023] [Indexed: 06/10/2023] Open
Abstract
Rationalized development of electrical stimulation (ES) therapy is of paramount importance. Not only it will foster new techniques and technologies with increased levels of safety, efficacy, and efficiency, but it will also facilitate the translation from basic research to clinical practice. For such endeavor, design of new technologies must dialogue with state-of-the-art neuroscientific knowledge. By its turn, neuroscience is transitioning-a movement started a couple of decades earlier-into adopting a new conceptual framework for brain architecture, in which time and thus temporal patterns plays a central role in the neuronal representation of sampled data from the world. This article discusses how neuroscience has evolved to understand the importance of brain rhythms in the overall functional architecture of the nervous system and, consequently, that neuromodulation research should embrace this new conceptual framework. Based on such support, we revisit the literature on standard (fixed-frequency pulsatile stimuli) and mostly non-standard patterns of ES to put forward our own rationale on how temporally complex stimulation schemes may impact neuromodulation strategies. We then proceed to present a low frequency, on average (thus low energy), scale-free temporally randomized ES pattern for the treatment of experimental epilepsy, devised by our group and termed NPS (Non-periodic Stimulation). The approach has been shown to have robust anticonvulsant effects in different animal models of acute and chronic seizures (displaying dysfunctional hyperexcitable tissue), while also preserving neural function. In our understanding, accumulated mechanistic evidence suggests such a beneficial mechanism of action may be due to the natural-like characteristic of a scale-free temporal pattern that may robustly compete with aberrant epileptiform activity for the recruitment of neural circuits. Delivering temporally patterned or random stimuli within specific phases of the underlying oscillations (i.e., those involved in the communication within and across brain regions) could both potentiate and disrupt the formation of neuronal assemblies with random probability. The usage of infinite improbability drive here is obviously a reference to the "The Hitchhiker's Guide to the Galaxy" comedy science fiction classic, written by Douglas Adams. The parallel is that dynamically driving brain functional connectogram, through neuromodulation, in a manner that would not favor any specific neuronal assembly and/or circuit, could re-stabilize a system that is transitioning to fall under the control of a single attractor. We conclude by discussing future avenues of investigation and their potentially disruptive impact on neurotechnology, with a particular interest in NPS implications in neural plasticity, motor rehabilitation, and its potential for clinical translation.
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Affiliation(s)
- Vinícius Rosa Cota
- Rehab Technologies - INAIL Lab, Istituto Italiano di Tecnologia, Genoa, Italy
- Laboratory of Neuroengineering and Neuroscience, Department of Electrical Engineering, Federal University of São João del-Rei, São João del Rei, Brazil
| | - Sérgio Augusto Vieira Cançado
- Núcleo Avançado de Tratamento das Epilepsias (NATE), Felício Rocho Hospital, Fundação Felice Rosso, Belo Horizonte, Brazil
| | - Márcio Flávio Dutra Moraes
- Department of Physiology and Biophysics, Núcleo de Neurociências, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Boyko M, Gruenbaum BF, Frank D, Natanel D, Negev S, Azab AN, Barsky G, Knyazer B, Kofman O, Zlotnik A. The Integrity of the Blood-Brain Barrier as a Critical Factor for Regulating Glutamate Levels in Traumatic Brain Injury. Int J Mol Sci 2023; 24:ijms24065897. [PMID: 36982969 PMCID: PMC10056818 DOI: 10.3390/ijms24065897] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/16/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
A healthy blood-brain barrier (BBB) shields the brain from high concentrations of blood glutamate, which can cause neurotoxicity and neurodegeneration. It is believed that traumatic brain injury (TBI) causes long-term BBB disruption, subsequently increasing brain glutamate in the blood, in addition to increased glutamate resulting from the neuronal injury. Here, we investigate the relationship between blood and brain glutamate levels in the context of BBB permeability. Rats exposed to BBB disruption through an osmotic model or TBI and treated with intravenous glutamate or saline were compared to control rats with an intact BBB treated with intravenous glutamate or saline. After BBB disruption and glutamate administration, the concentrations of glutamate in the cerebrospinal fluid and blood and brain tissue were analyzed. The results showed a strong correlation between the brain and blood glutamate concentrations in the groups with BBB disruption. We conclude that a healthy BBB protects the brain from high levels of blood glutamate, and the permeability of the BBB is a vital component in regulating levels of glutamate in the brain. These findings bring a new approach to treating the consequences of TBI and other diseases where long-term disruption of the BBB is the central mechanism of their development.
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Affiliation(s)
- Matthew Boyko
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel
| | - Benjamin F Gruenbaum
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Dmitry Frank
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel
| | - Dmitry Natanel
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel
| | - Shahar Negev
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel
| | - Abed N Azab
- Department of Nursing, Recanati School for Community Health Professions, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel
| | - Guy Barsky
- Department of Surgery B, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel
| | - Boris Knyazer
- Department of Ophthalmology, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel
| | - Ora Kofman
- Department of Psychology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel
| | - Alexander Zlotnik
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel
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13
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Riva M, Moriceau S, Morabito A, Dossi E, Sanchez-Bellot C, Azzam P, Navas-Olive A, Gal B, Dori F, Cid E, Ledonne F, David S, Trovero F, Bartolomucci M, Coppola E, Rebola N, Depaulis A, Rouach N, de la Prida LM, Oury F, Pierani A. Aberrant survival of hippocampal Cajal-Retzius cells leads to memory deficits, gamma rhythmopathies and susceptibility to seizures in adult mice. Nat Commun 2023; 14:1531. [PMID: 36934089 PMCID: PMC10024761 DOI: 10.1038/s41467-023-37249-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 03/08/2023] [Indexed: 03/20/2023] Open
Abstract
Cajal-Retzius cells (CRs) are transient neurons, disappearing almost completely in the postnatal neocortex by programmed cell death (PCD), with a percentage surviving up to adulthood in the hippocampus. Here, we evaluate CR's role in the establishment of adult neuronal and cognitive function using a mouse model preventing Bax-dependent PCD. CRs abnormal survival resulted in impairment of hippocampus-dependent memory, associated in vivo with attenuated theta oscillations and enhanced gamma activity in the dorsal CA1. At the cellular level, we observed transient changes in the number of NPY+ cells and altered CA1 pyramidal cell spine density. At the synaptic level, these changes translated into enhanced inhibitory currents in hippocampal pyramidal cells. Finally, adult mutants displayed an increased susceptibility to lethal tonic-clonic seizures in a kainate model of epilepsy. Our data reveal that aberrant survival of a small proportion of postnatal hippocampal CRs results in cognitive deficits and epilepsy-prone phenotypes in adulthood.
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Affiliation(s)
- Martina Riva
- Université Paris Cité, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, 75015, Paris, France
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, 75014, Paris, France
| | - Stéphanie Moriceau
- Platform for Neurobehavioral and metabolism, Structure Fédérative de Recherche Necker, 26 INSERM US24/CNRS UAR, 3633, Paris, France
| | - Annunziato Morabito
- Sorbonne Université, Institut Du Cerveau-Paris Brain Institute-ICM, Inserm U1127, CNRS UMR 7225, 47 Boulevard de l'Hopital, 75013, Paris, France
| | - Elena Dossi
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Labex Memolife, Université PSL, Paris, France
| | | | - Patrick Azzam
- Université Paris Cité, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, 75015, Paris, France
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, 75014, Paris, France
| | | | - Beatriz Gal
- Instituto Cajal, CSIC, Madrid, Spain
- Universidad Camilo José Cela, Madrid, Spain
| | - Francesco Dori
- Université Paris Cité, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, 75015, Paris, France
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, 75014, Paris, France
| | - Elena Cid
- Instituto Cajal, CSIC, Madrid, Spain
| | - Fanny Ledonne
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, 75014, Paris, France
| | - Sabrina David
- Key-Obs SAS, 13 avenue Buffon, 45100, Orléans, France
| | | | - Magali Bartolomucci
- Université Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, 38000, Grenoble, France
| | - Eva Coppola
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, 75014, Paris, France
| | - Nelson Rebola
- Sorbonne Université, Institut Du Cerveau-Paris Brain Institute-ICM, Inserm U1127, CNRS UMR 7225, 47 Boulevard de l'Hopital, 75013, Paris, France
| | - Antoine Depaulis
- Université Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, 38000, Grenoble, France
| | - Nathalie Rouach
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Labex Memolife, Université PSL, Paris, France
| | | | - Franck Oury
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades-INEM, 75015, Paris, France
| | - Alessandra Pierani
- Université Paris Cité, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, 75015, Paris, France.
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, 75014, Paris, France.
- GHU Paris Psychiatrie et Neurosciences, Hôpital Sainte Anne, 75014, Paris, France.
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14
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Limbic and olfactory cortical circuits in focal seizures. Neurobiol Dis 2023; 178:106007. [PMID: 36682502 DOI: 10.1016/j.nbd.2023.106007] [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: 12/29/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/22/2023] Open
Abstract
Epilepsies affecting the limbic regions are common and generate seizures often resistant to pharmacological treatment. Clinical evidence demonstrates that diverse regions of the mesial portion of the temporal lobe participate in limbic seizures; these include the hippocampus, the entorhinal, perirhinal and parahippocampal regions and the piriform cortex. The network mechanisms involved in the generation of olfactory-limbic epileptiform patterns will be here examined, with particular emphasis on acute interictal and ictal epileptiform discharges obtained by treatment with pro-convulsive drugs and by high-frequency stimulations on in vitro preparations, such as brain slices and the isolated guinea pig brain. The interactions within olfactory-limbic circuits can be summarized as follows: independent, region-specific seizure-like events (SLE) are generated in the olfactory and in the limbic cortex; SLEs generated in the hippocampal-parahippocampal regions tend to remain within these areas; the perirhinal region controls the neocortical propagation and the generalization of limbic seizures; interictal spiking in the olfactory regions prevents the invasion by SLEs generated in limbic regions. The potential relevance of these observations for human focal epilepsy is discussed.
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15
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Wickham J, Ledri M, Andersson M, Kokaia M. Cell-specific switch for epileptiform activity: critical role of interneurons in the mouse subicular network. Cereb Cortex 2023; 33:6171-6183. [PMID: 36611229 PMCID: PMC10183737 DOI: 10.1093/cercor/bhac493] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 01/09/2023] Open
Abstract
During epileptic seizures, neuronal network activity is hyper synchronized whereby GABAergic parvalbumin-interneurons may have a key role. Previous studies have mostly utilized 4-aminopyridine to induce epileptiform discharges in brain slices from healthy animals. However, it is not clear if the seizure-triggering ability of parvalbumin-interneurons also holds true without the use of external convulsive agents. Here, we investigate whether synchronized activation of parvalbumin-interneurons or principal cells can elicit epileptiform discharges in subiculum slices of epileptic mice. We found that selective synchronized activation of parvalbumin-interneurons or principal cells with optogenetics do not result in light-induced epileptiform discharges (LIEDs) neither in epileptic nor in normal brain slices. Adding 4-aminopyridine to slices, activation of parvalbumin-interneurons still failed to trigger LIEDs. In contrast, such activation of principal neurons readily generated LIEDs with features resembling afterdischarges. When GABAA receptor blocker was added to the perfusion medium, the LIEDs were abolished. These results demonstrate that in subiculum, selective synchronized activation of principal excitatory neurons can trigger epileptiform discharges by recruiting a large pool of downstream interneurons. This study also suggests region-specific role of principal neurons and interneurons in ictogenesis, opening towards differential targeting of specific brain areas for future treatment strategies tailored for individual patients with epilepsy.
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Affiliation(s)
- J Wickham
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
| | - M Ledri
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
| | - M Andersson
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
| | - M Kokaia
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
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The Anti-Seizure Effect of Liraglutide on Ptz-Induced Convulsions Through its Anti-Oxidant and Anti-Inflammatory Properties. Neurochem Res 2023; 48:188-195. [PMID: 36040609 DOI: 10.1007/s11064-022-03736-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 01/11/2023]
Abstract
Epilepsy is a prevalent and frequently devastating neurological disorder defined by recurring spontaneous seizures caused by aberrant electrical activity in the brain. Over ten million people worldwide suffer from drug-resistant epilepsy. This severe condition requires novel treatment approaches. Both oxidative and nitrosative stress are thought to have a role in the etiology of epilepsy. Liraglutide is a glucagon-like peptide-1 (GLP-1) analogue that is used to treat type-2 diabetes mellitus. According to recent studies, Liraglutide also shows neuroprotective properties, improving memory retention and total hippocampus pyramidal neuronal population in mice. The purpose of this investigation was to determine the anti-seizure and anti-oxidative effects of liraglutide in a pentylenetetrazole (PTZ)-induced rat model of epilepsy. 48 rats were randomly assigned to two groups: those who had electroencephalography (EEG) recordings and those who underwent behavioral assessment. Rats received either intraperitoneal (IP) liraglutide at two different dosages (3-6 mg/kg) or a placebo, followed by pentylenetetrazole (IP). To determine if liraglutide has anti-seizure characteristics, we examined seizure activity in rats using EEG, the Racine convulsion scale (RCS), the time of first myoclonic jerk (FMJ), and MDA, SOD, TNF-α, IL-1β and GAD-67 levels. The mean EEG spike wave percentage score was reduced from 75.8% (placebo) to 59.4% (lower-dose) and 41.5% (higher-dose). FMJ had increased from a mean of 70.6 s (placebo) to 181.2 s (lower-dose) and 205.2 s (higher-dose). RCS was reduced from a mean of 5.5 (placebo) to 2.7 (lower-dose) and 2.4 (higher-dose). Liraglutide (3 and 6 mg/kg i.p.) successfully decreased the spike percentages and RCS associated with PTZ induced epilepsy, as well as considerably decreased MDA, TNF-α, IL-1β and elevated SOD, GAD-67 levels in rat brain. Liraglutide significantly decreased seizure activity at both dosages when compared to control, most likely due to its anti-oxidant and anti-inflammatory properties. The potential clinical role of liraglutide as an anti-seizure medication should be further explored.
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17
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Zahir M, Rashidian A, Hoseini M, Akbarian R, Chamanara M. Pharmacological evidence for the possible involvement of the NMDA receptor pathway in the anticonvulsant effect of tramadol in mice. AIMS Neurosci 2022; 9:444-453. [PMID: 36660072 PMCID: PMC9826747 DOI: 10.3934/neuroscience.2022024] [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: 08/18/2022] [Revised: 10/28/2022] [Accepted: 11/05/2022] [Indexed: 11/13/2022] Open
Abstract
Background Previous studies have shown controversial results regarding the pro- or anticonvulsant effects of tramadol. Additionally, the underlying mechanism of seizure induction or alleviation by tramadol has not been fully understood. In the current study, the effects of tramadol on pentylenetetrazole (PTZ)-induced seizure and the possible involvement of the N-methyl-D-aspartate (NMDA) pathway were assessed in mice. Methods Male Naval Medical Research Institute (NMRI) mice were treated with intravenous infusion of PTZ in order to induce clonic seizures and determine seizure threshold. Tramadol was injected intraperitoneally (0.1-150 mg/kg) 30 minutes prior to elicitation of seizures. The possible effects of intraperitoneal injections of NMDA receptor antagonists, ketamine (0.5 mg/kg) and MK-801 (0.5 mg/kg) on the anticonvulsant property of tramadol were investigated subsequently. Results Tramadol (1-100 mg/kg) increased PTZ-induced seizure threshold in a dose-dependent, time-independent manner, with optimal anticonvulsant effect at a dose of 100 mg/kg. Acute administration of either ketamine (0.5 mg/kg) or MK-801 (0.5 mg/kg) potentiated the anticonvulsant effect of a subeffective dose of tramadol (0.3 mg/kg). Conclusion These results suggest a possible role of the NMDA pathway in the anticonvulsant effect of tramadol.
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Affiliation(s)
- Mazyar Zahir
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Amir Rashidian
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran,Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohsen Hoseini
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran,Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Reyhaneh Akbarian
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohsen Chamanara
- Department of Pharmacology, School of Medicine, Aja University of Medical Sciences, P.O. Box 1411718541, Tehran, Iran,* Correspondence:
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Khodadadi M, Zare M, Rezaei M, Bakhtiarzadeh F, Barkley V, Shojaei A, Raoufy MR, Mirnajafi-Zadeh J. Effect of low frequency stimulation of olfactory bulb on seizure severity, learning, and memory in kindled rats. Epilepsy Res 2022; 188:107055. [DOI: 10.1016/j.eplepsyres.2022.107055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/04/2022] [Accepted: 11/18/2022] [Indexed: 11/21/2022]
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Soboleva EB, Amakhin DV, Sinyak DS, Zaitsev AV. Modulation of seizure-like events by the small conductance and ATP-sensitive potassium ion channels. Biochem Biophys Res Commun 2022; 623:74-80. [PMID: 35878426 DOI: 10.1016/j.bbrc.2022.07.057] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/14/2022] [Accepted: 07/14/2022] [Indexed: 11/27/2022]
Abstract
Potassium ion channels are extensively involved in the regulation of epileptic seizures. The small conductance calcium-sensitive potassium channels (SK channels) and ATP-sensitive potassium (KATP) channels are activated by calcium ion entry and decrease ATP levels, respectively. These channels can underlie the post-burst afterhyperpolarization and be upregulated during seizures, providing negative feedback during epileptic activity. Using the whole-cell patch-clamp method in rat brain slices, we investigated the effect of SK- and KATP-affecting drugs on seizure-like events (SLEs) in the 4-aminopyridine model of epileptic seizures in vitro. We demonstrate that SK and KATP channels contribute to sustaining the high-frequency firing of the principal neurons in the deep layers of the entorhinal cortex during injections of depolarizing current and epileptiform discharges. Neither the pharmacological blockade nor the activation of these channels was able to prevent the epileptiform activity in brain slices. However, the blockade of KATP channels increases the SLE duration, suggesting that these channels may contribute to the termination of SLEs. Thus, KATP channels can be considered a promising target for pharmacological interventions for the treatment of epilepsy.
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Affiliation(s)
- Elena B Soboleva
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, 44, Toreza Prospekt, Saint Petersburg, 194223, Russia
| | - Dmitry V Amakhin
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, 44, Toreza Prospekt, Saint Petersburg, 194223, Russia
| | - Denis S Sinyak
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, 44, Toreza Prospekt, Saint Petersburg, 194223, Russia
| | - Aleksey V Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, 44, Toreza Prospekt, Saint Petersburg, 194223, Russia.
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Réboli LA, Maciel RM, de Oliveira JC, Moraes MFD, Tilelli CQ, Cota VR. Persistence of neural function in animals submitted to seizure-suppressing scale-free nonperiodic electrical stimulation applied to the amygdala. Behav Brain Res 2022; 426:113843. [PMID: 35304185 DOI: 10.1016/j.bbr.2022.113843] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 02/11/2022] [Accepted: 03/11/2022] [Indexed: 11/02/2022]
Abstract
Based on the rationale that neural hypersynchronization underlies epileptic phenomena, nonperiodic stimulation (NPS) was designed and successfully tested as an electrical stimulus with robust anticonvulsant action. Considering the scale-free temporal structure of NPS mimics natural-like activity, here we hypothesized its application to the amygdala would induce minor to none impairment of neural function in treated animals. Wistar rats underwent gold-standard behavioral tests such as open field (OF), elevated plus-maze (EPM), novel object recognition, and social interaction test in order to evaluate the functions of base-level anxiety, motor function, episodic memory, and sociability. We also performed daily (8 days, 6 h per day) electrophysiological recordings (local field potential/LFP and electromyography) to assess global forebrain dynamics and the sleep-wake cycle architecture and integrity. All animals displayed an increased proportion of time exploring new objects, spent more time in the closed arms of the EPM and in the periphery of the OF arena, with similar numbers of crossing between quadrants and no significant changes of social behaviors. In the sleep-wake cycle electrophysiology experiments, we found no differences regarding duration and proportion of sleep stages and the number of transitions between stages. Finally, the power spectrum of LFP recordings and neurodynamics were also unaltered. We concluded that NPS did not impair neural functions evaluated and thus, it may be safe for clinical studies. Additionally, results corroborate the notion that NPS may exert an on-demand only desynchronization effect by efficiently competing with epileptiform activity for the physiological and healthy recruitment of neural circuitry. Considering the very dynamical nature of circuit activation and functional activity underlying neural function in general (including cognition, processing of emotion, memory acquisition, and sensorimotor integration) and its corruption leading to disorder, such mechanism of action may have important implications in the investigation of neuropsychological phenomena and also in the development of rehabilitation neurotechnology.
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Affiliation(s)
- Larissa Altoé Réboli
- Laboratory of Neuroengineering and Neuroscience (LINNce), Department of Electrical Engineering, Federal University of São João Del-Rei. Pça. Frei Orlando, 170 - Centro, São João Del-Rei, MG 36302-357, Brazil
| | - Renato Marciano Maciel
- Laboratory of Neuroengineering and Neuroscience (LINNce), Department of Electrical Engineering, Federal University of São João Del-Rei. Pça. Frei Orlando, 170 - Centro, São João Del-Rei, MG 36302-357, Brazil; Centre de Recherche en Neurosciences de Lyon (CRNL), UMR 5292 CNRS/U1028 INSERM and Université de Lyon, Lyon I, Neurocampus-Michel Jouvet, 95 Boulevard Pinel, 69500 Bron, France
| | - Jasiara Carla de Oliveira
- Laboratory of Neuroengineering and Neuroscience (LINNce), Department of Electrical Engineering, Federal University of São João Del-Rei. Pça. Frei Orlando, 170 - Centro, São João Del-Rei, MG 36302-357, Brazil; UNIPTAN - Centro Universitário Presidente Tancredo de Almeida Neves, Av. Leite de Castro, 1101 - Fábricas, São João Del Rei, MG 36301-182, Brazil
| | - Márcio Flávio Dutra Moraes
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627 - Campus Pampulha, Belo Horizonte, MG 31270-901, Brazil
| | - Cristiane Queixa Tilelli
- Laboratory of Physiology, Campus Centro-Oeste Dona Lindu, Universidade Federal de São João del-Rei, Av. Sebastião Gonçalves Coelho, 400 - Belvedere, Divinópolis, MG, 35.501-296, Brazil
| | - Vinícius Rosa Cota
- Laboratory of Neuroengineering and Neuroscience (LINNce), Department of Electrical Engineering, Federal University of São João Del-Rei. Pça. Frei Orlando, 170 - Centro, São João Del-Rei, MG 36302-357, Brazil.
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21
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Caron D, Canal-Alonso Á, Panuccio G. Mimicking CA3 Temporal Dynamics Controls Limbic Ictogenesis. BIOLOGY 2022; 11:371. [PMID: 35336745 PMCID: PMC8944954 DOI: 10.3390/biology11030371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 06/14/2023]
Abstract
Mesial temporal lobe epilepsy (MTLE) is the most common partial complex epilepsy in adults and the most unresponsive to medications. Electrical deep brain stimulation (DBS) of the hippocampus has proved effective in controlling seizures in epileptic rodents and in drug-refractory MTLE patients. However, current DBS paradigms implement arbitrary fixed-frequency or patterned stimuli, disregarding the temporal profile of brain electrical activity. The latter, herein included hippocampal spontaneous firing, has been shown to follow lognormal temporal dynamics. Here, we present a novel paradigm to devise DBS protocols based on stimulation patterns fashioned as a surrogate brain signal. We focus on the interictal activity originating in the hippocampal subfield CA3, which has been shown to be anti-ictogenic. Using 4-aminopyridine-treated hippocampus-cortex slices coupled to microelectrode array, we pursue three specific aims: (1) address whether lognormal temporal dynamics can describe the CA3-driven interictal pattern, (2) explore the possibility of restoring the non-seizing state by mimicking the temporal dynamics of this anti-ictogenic pattern with electrical stimulation, and (3) compare the performance of the CA3-surrogate against periodic stimulation. We show that the CA3-driven interictal activity follows lognormal temporal dynamics. Further, electrical stimulation fashioned as a surrogate interictal pattern exhibits similar efficacy but uses less pulses than periodic stimulation. Our results support the possibility of mimicking the temporal dynamics of relevant brain signals as a straightforward DBS strategy to ameliorate drug-refractory epilepsy. Further, they herald a paradigm shift in neuromodulation, wherein a compromised brain signal can be recreated by the appropriate stimuli distribution to bypass trial-and-error studies and attain physiologically meaningful DBS operating modes.
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Affiliation(s)
- Davide Caron
- Enhanced Regenerative Medicine, Istituto Italiano di Tecnologia, 16163 Genova, Italy;
| | - Ángel Canal-Alonso
- BISITE Research Group, University of Salamanca, 37008 Salamanca, Spain;
- Institute for Biomedical Research of Salamanca, University of Salamanca, 37008 Salamanca, Spain
| | - Gabriella Panuccio
- Enhanced Regenerative Medicine, Istituto Italiano di Tecnologia, 16163 Genova, Italy;
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22
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Domínguez-Sala E, Andreu-Cervera A, Martín-Climent P, Murcia-Ramón R, Martínez S, Geijo-Barrientos E. Properties of the epileptiform activity in the cingulate cortex of a mouse model of LIS1 dysfunction. Brain Struct Funct 2022; 227:1599-1614. [PMID: 35103859 PMCID: PMC9098610 DOI: 10.1007/s00429-022-02458-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 01/09/2022] [Indexed: 11/02/2022]
Abstract
Dysfunction of the LIS1 gene causes lissencephaly, a drastic neurological disorder characterized by a deep disruption of the cortical structure. We aim to uncover alterations of the cortical neuronal networks related with the propagation of epileptiform activity in the Lis1/sLis1 mouse, a model lacking the LisH domain in heterozygosis. We did extracellular field-potential and intracellular recordings in brain slices of the anterior cingulate cortex (ACC) or the retrosplenial cortex (RSC) to study epileptiform activity evoked in the presence of bicuculline (10 µM), a blocker of GABAA receptors. The sensitivity to bicuculline of the generation of epileptiform discharges was similar in wild type (WT) and Lis1/sLis1 cortex (EC50 1.99 and 2.24 µM, respectively). In the Lis1/sLis1 cortex, we observed a decreased frequency of the oscillatory post-discharges of the epileptiform events; also, the propagation of epileptiform events along layer 2/3 was slower in the Lis1/sLis1 cortex (WT 47.69 ± 2.16 mm/s, n = 25; Lis1/sLis1 37.34 ± 2.43 mm/s, n = 15; p = 0.004). The intrinsic electrophysiological properties of layer 2/3 pyramidal neurons were similar in WT and Lis1/sLis1 cortex, but the frequency of the spontaneous EPSCs was lower and their peak amplitude higher in Lis1/sLis1 pyramidal neurons. Finally, the propagation of epileptiform activity was differently affected by AMPA receptor blockers: CNQX had a larger effect in both ACC and RSC while GYKI53655 had a larger effect only in the ACC in the WT and Lis1/sLis1 cortex. All these changes indicate that the dysfunction of the LIS1 gene causes abnormalities in the properties of epileptiform discharges and in their propagation along the layer 2/3 in the anterior cingulate cortex and in the restrosplenial cortex.
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Affiliation(s)
- E Domínguez-Sala
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Campus de San Juan, C/Ramón y Cajal sn, San Juan de Alicante, 03550, Alicante, Spain.
| | - A Andreu-Cervera
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Campus de San Juan, C/Ramón y Cajal sn, San Juan de Alicante, 03550, Alicante, Spain
| | - P Martín-Climent
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Campus de San Juan, C/Ramón y Cajal sn, San Juan de Alicante, 03550, Alicante, Spain
| | - R Murcia-Ramón
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Campus de San Juan, C/Ramón y Cajal sn, San Juan de Alicante, 03550, Alicante, Spain
| | - S Martínez
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Campus de San Juan, C/Ramón y Cajal sn, San Juan de Alicante, 03550, Alicante, Spain.,Centro de Investigación Biomédica en Red en Salud Mental (CIBERSAM, Spain), Madrid, Spain
| | - Emilio Geijo-Barrientos
- Instituto de Neurociencias, Universidad Miguel Hernández-CSIC, Campus de San Juan, C/Ramón y Cajal sn, San Juan de Alicante, 03550, Alicante, Spain.
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23
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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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24
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Perisomatic Inhibition and Its Relation to Epilepsy and to Synchrony Generation in the Human Neocortex. Int J Mol Sci 2021; 23:ijms23010202. [PMID: 35008628 PMCID: PMC8745731 DOI: 10.3390/ijms23010202] [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: 11/17/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 11/21/2022] Open
Abstract
Inhibitory neurons innervating the perisomatic region of cortical excitatory principal cells are known to control the emergence of several physiological and pathological synchronous events, including epileptic interictal spikes. In humans, little is known about their role in synchrony generation, although their changes in epilepsy have been thoroughly investigated. This paper demonstraits how parvalbumin (PV)- and type 1 cannabinoid receptor (CB1R)-positive perisomatic interneurons innervate pyramidal cell bodies, and their role in synchronous population events spontaneously emerging in the human epileptic and non-epileptic neocortex, in vitro. Quantitative electron microscopy showed that the overall, PV+ and CB1R+ somatic inhibitory inputs remained unchanged in focal cortical epilepsy. On the contrary, the size of PV-stained synapses increased, and their number decreased in epileptic samples, in synchrony generating regions. Pharmacology demonstrated—in conjunction with the electron microscopy—that although both perisomatic cell types participate, PV+ cells have stronger influence on the generation of population activity in epileptic samples. The somatic inhibitory input of neocortical pyramidal cells remained almost intact in epilepsy, but the larger and consequently more efficient somatic synapses might account for a higher synchrony in this neuron population. This, together with epileptic hyperexcitability, might make a cortical region predisposed to generate or participate in hypersynchronous events.
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25
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Ghasemi Z, Naderi N, Shojaei A, Raoufy MR, Ahmadirad N, Barkley V, Mirnajafi-Zadeh J. Group I metabotropic glutamate receptors contribute to the antiepileptic effect of electrical stimulation in hippocampal CA1 pyramidal neurons. Epilepsy Res 2021; 178:106821. [PMID: 34839145 DOI: 10.1016/j.eplepsyres.2021.106821] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 11/04/2021] [Accepted: 11/16/2021] [Indexed: 11/17/2022]
Abstract
Low-frequency deep brain stimulation (LFS) inhibits neuronal hyperexcitability during epilepsy. Accordingly, the use of LFS as a treatment method for patients with drug-resistant epilepsy has been proposed. However, the LFS antiepileptic mechanisms are not fully understood. Here, the role of metabotropic glutamate receptors group I (mGluR I) in LFS inhibitory action on epileptiform activity (EA) was investigated. EA was induced by increasing the K+ concentration in artificial cerebrospinal fluid (ACSF) up to 12 mM in hippocampal slices of male Wistar rats. LFS (1 Hz, 900 pulses) was delivered to the bundles of Schaffer collaterals at the beginning of EA. The excitability of CA1 pyramidal neurons was assayed by intracellular whole-cell recording. Applying LFS reduced the firing frequency during EA and substantially moved the membrane potential toward repolarization after a high-K+ ACSF washout. In addition, LFS attenuated the EA-generated neuronal hyperexcitability. A blockade of both mGluR 1 and mGluR 5 prevented the inhibitory action of LFS on EA-generated neuronal hyperexcitability. Activation of mGluR I mimicked the LFS effects and had similar inhibitory action on excitability of CA1 pyramidal neurons following EA. However, mGluR I agonist's antiepileptic action was not as strong as LFS. The observed LFS effects were significantly attenuated in the presence of a PKC inhibitor. Altogether, the LFS' inhibitory action on neuronal hyperexcitability following EA relies, in part, on the activity of mGluR I and a PKC-related signaling pathway.
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Affiliation(s)
- Zahra Ghasemi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Nima Naderi
- Department of Pharmacology and Toxicology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Amir Shojaei
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mohammad Reza Raoufy
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Nooshin Ahmadirad
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Victoria Barkley
- Krembil Research Institute, University Health Network, Toronto, Canada
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran.
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26
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Lu YL, Scharfman HE. New Insights and Methods for Recording and Imaging Spontaneous Spreading Depolarizations and Seizure-Like Events in Mouse Hippocampal Slices. Front Cell Neurosci 2021; 15:761423. [PMID: 34899190 PMCID: PMC8663723 DOI: 10.3389/fncel.2021.761423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 10/04/2021] [Indexed: 11/30/2022] Open
Abstract
Spreading depolarization (SD) is a sudden, large, and synchronous depolarization of principal cells which also involves interneurons and astrocytes. It is followed by depression of neuronal activity, and it slowly propagates across brain regions like cortex or hippocampus. SD is considered to be mechanistically relevant to migraine, epilepsy, and traumatic brain injury (TBI), but there are many questions about its basic neurophysiology and spread. Research into SD in hippocampus using slices is often used to gain insight and SD is usually triggered by a focal stimulus with or without an altered extracellular buffer. Here, we optimize an in vitro experimental model allowing us to record SD without focal stimulation, which we call spontaneous. This method uses only an altered extracellular buffer containing 0 mM Mg2+ and 5 mM K+ and makes it possible for simultaneous patch and extracellular recording in a submerged chamber plus intrinsic optical imaging in slices of either sex. We also add methods for quantification and show the quantified optical signal is much more complex than imaging alone would suggest. In brief, acute hippocampal slices were prepared with a chamber holding a submerged slice but with flow of artificial cerebrospinal fluid (aCSF) above and below, which we call interface-like. As soon as slices were placed in the chamber, aCSF with 0 Mg2+/5 K+ was used. Most mouse slices developed SD and did so in the first hour of 0 Mg2+/5 K+ aCSF exposure. In addition, prolonged bursts we call seizure-like events (SLEs) occurred, and the interactions between SD and SLEs suggest potentially important relationships. Differences between rats and mice in different chambers are described. Regarding optical imaging, SD originated in CA3 and the pattern of spread to CA1 and the dentate gyrus was similar in some ways to prior studies but also showed interesting differences. In summary, the methods are easy to use, provide new opportunities to study SD, new insights, and are inexpensive. They support previous suggestions that SD is diverse, and also suggest that participation by the dentate gyrus merits greater attention.
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Affiliation(s)
- Yi-Ling Lu
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
| | - Helen E. Scharfman
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
- Department of Child and Adolescent Psychiatry, New York University Langone Health, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Langone Health, New York, NY, United States
- Department of Psychiatry, New York University Langone Health, New York, NY, United States
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27
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Amakhin DV, Soboleva EB, Chizhov AV, Zaitsev AV. Insertion of Calcium-Permeable AMPA Receptors during Epileptiform Activity In Vitro Modulates Excitability of Principal Neurons in the Rat Entorhinal Cortex. Int J Mol Sci 2021; 22:12174. [PMID: 34830051 PMCID: PMC8621524 DOI: 10.3390/ijms222212174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/05/2021] [Accepted: 11/07/2021] [Indexed: 12/19/2022] Open
Abstract
Epileptic activity leads to rapid insertion of calcium-permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (CP-AMPARs) into the synapses of cortical and hippocampal glutamatergic neurons, which generally do not express them. The physiological significance of this process is not yet fully understood; however, it is usually assumed to be a pathological process that augments epileptic activity. Using whole-cell patch-clamp recordings in rat entorhinal cortex slices, we demonstrate that the timing of epileptiform discharges, induced by 4-aminopyridine and gabazine, is determined by the shunting effect of Ca2+-dependent slow conductance, mediated predominantly by K+-channels. The blockade of CP-AMPARs by IEM-1460 eliminates this extra conductance and consequently increases the rate of discharge generation. The blockade of NMDARs reduced the additional conductance to a lesser extent than the blockade of CP-AMPARs, indicating that CP-AMPARs are a more significant source of intracellular Ca2+. The study's main findings were implemented in a mathematical model, which reproduces the shunting effect of activity-dependent conductance on the generation of discharges. The obtained results suggest that the expression of CP-AMPARs in principal neurons reduces the discharge generation rate and may be considered as a protective mechanism.
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Affiliation(s)
- Dmitry V. Amakhin
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Toreza Prospekt 44, 194223 Saint Petersburg, Russia; (D.V.A.); (E.B.S.); (A.V.C.)
| | - Elena B. Soboleva
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Toreza Prospekt 44, 194223 Saint Petersburg, Russia; (D.V.A.); (E.B.S.); (A.V.C.)
| | - Anton V. Chizhov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Toreza Prospekt 44, 194223 Saint Petersburg, Russia; (D.V.A.); (E.B.S.); (A.V.C.)
- Ioffe Institute, Russian Academy of Sciences, Polytekhnicheskaya 26, 194021 Saint Petersburg, Russia
| | - Aleksey V. Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Toreza Prospekt 44, 194223 Saint Petersburg, Russia; (D.V.A.); (E.B.S.); (A.V.C.)
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28
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Panteliadis C. Historical Sources on Epilepsy Surgery: From Antiquity Through the End 20th Century. Open Neurol J 2021. [DOI: 10.2174/1874205x02115010052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The history of epilepsy is an associate of humanity, and the reports date back to antiquity. Almost all ancient cultures, including the Babylonians, Egyptians, Greeks, Indians in pre-Buddhist period, Iranians, Chinese, and Byzantine epoch, bear witness to epilepsy. Therefore, the earliest beginnings of surgical treatment and epilepsy surgery can be traced back to antiquity. Trepanation as an attempt to treat the disease has often been found in prehistorical tombs (Neolithicum). In antiquity, fasting, a healthy diet, regulation of excretions, medical gymnastics and a decent lifestyle were used as treatment for epilepsy as a non-surgical solution. In the Middle Ages, the basis for treatment fell into three main categories: Conventional (diet and botanical remedies), magical (phases of the moon, trephining of the skull) and religious beliefs (fasting, prayer, exorcisms, and social marginalization).
The first neurosurgical operations on epileptic patients with focal semiology were performed during the early 19th century, and began with Godlee, Sommer, Macewen and later Horsley. From that time on, discoveries on epilepsy surgery progressed at a faster pace that started in a historical journey from ancient times until the end of the 20th century.
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29
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Chindo BA, Howes MJR, Abuhamdah S, Yakubu MI, Ayuba GI, Battison A, Chazot PL. New Insights Into the Anticonvulsant Effects of Essential Oil From Melissa officinalis L. (Lemon Balm). Front Pharmacol 2021; 12:760674. [PMID: 34721045 PMCID: PMC8551917 DOI: 10.3389/fphar.2021.760674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 09/27/2021] [Indexed: 11/25/2022] Open
Abstract
Melissa officinalis L. is used in traditional European and Iranian folk medicines to treat a plethora of neurological diseases including epilepsy. We utilized the in vitro and in vivo models of epilepsy to probe the anticonvulsant potentials of essential oil from M. officinalis (MO) to gain insight into the scientific basis for its applications in traditional medicine for the management of convulsive disorders. MO was evaluated for effects on maximal electroshock (MES) and pentylenetetrazole (PTZ) -induced seizures in mice, on 4–aminopyridine (4-AP)-brain slice model of epilepsy and sustained repetitive firing of current clamped neurons; and its ameliorative effects were examined on seizure severity, anxiety, depression, cognitive dysfunction, oxidative stress and neuronal cell loss in PTZ-kindled rats. MO reversibly blocked spontaneous ictal-like discharges in the 4-AP-brain slice model of epilepsy and secondary spikes from sustained repetitive firing, suggesting anticonvulsant effects and voltage-gated sodium channel blockade. MO protected mice from PTZ– and MES–induced seizures and mortality, and ameliorated seizure severity, fear-avoidance, depressive-like behavior, cognitive deficits, oxidative stress and neuronal cell loss in PTZ–kindled rats. The findings warrant further study for the potential use of MO and/or its constituent(s) as adjunctive therapy for epileptic patients.
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Affiliation(s)
- Ben A Chindo
- Department of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, Kaduna State University, Kaduna, Nigeria
| | | | - Sawsan Abuhamdah
- Department of Biosciences, Durham University, Durham, United Kingdom.,College of Pharmacy, Al Ain University, Abu Dhabi, United Arab Emirates.,Department of Biopharmaceutics and Clinical Pharmacy, Faculty of Pharmacy, University of Jordan, Amman, Jordan
| | - Musa I Yakubu
- Department of Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, Kaduna State University, Kaduna, Nigeria
| | - Godwin I Ayuba
- Department of Anatomic Pathology and Forensic Medicine, College of Medicine, Kaduna State University, Kaduna, Nigeria
| | | | - Paul L Chazot
- Department of Biosciences, Durham University, Durham, United Kingdom
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30
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Ghinda DC, Salimpour Y, Crone NE, Kang J, Anderson WS. Dynamical Analysis of Seizure in Epileptic Brain: a Dynamic Phase-Amplitude Coupling Estimation Approach. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021; 2021:5970-5973. [PMID: 34892478 DOI: 10.1109/embc46164.2021.9629778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cross-frequency coupling in general and phase-amplitude coupling (PAC) as a particular form of it, provides an opportunity to investigate the complex interactions between neural oscillations in the human brain and neurological disorders such as epilepsy. Using PAC detection methods on temporal sliding windows, we developed a map of dynamic PAC evolution to investigate the spatiotemporal changes occurring during ictal transitions in a patient with intractable mesial temporal lobe epilepsy. The map is built by computing the modulation index between the amplitude of high frequency oscillations and the phase of lower frequency rhythms from the intracranial stereoelectroencephalography recordings during seizure. Our preliminary results show early abnormal PAC changes occurring in the preictal state prior to the occurrence of clinical or visible electrographic seizure onset, and suggest that dynamic PAC measures may serve as a potential clinical technique for analyzing seizure dynamics.Clinical Relevance-Application of a dynamic temporal PAC map as a new tool may provide novel insights into the neurophysiology of epileptic seizure activity and its spatio-temporal dynamics.
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Akyuz E, Koklu B, Uner A, Angelopoulou E, Paudel YN. Envisioning the role of inwardly rectifying potassium (Kir) channel in epilepsy. J Neurosci Res 2021; 100:413-443. [PMID: 34713909 DOI: 10.1002/jnr.24985] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 09/23/2021] [Accepted: 10/01/2021] [Indexed: 01/29/2023]
Abstract
Epilepsy is a devastating neurological disorder characterized by recurrent seizures attributed to the disruption of the dynamic excitatory and inhibitory balance in the brain. Epilepsy has emerged as a global health concern affecting about 70 million people worldwide. Despite recent advances in pre-clinical and clinical research, its etiopathogenesis remains obscure, and there are still no treatment strategies modifying disease progression. Although the precise molecular mechanisms underlying epileptogenesis have not been clarified yet, the role of ion channels as regulators of cellular excitability has increasingly gained attention. In this regard, emerging evidence highlights the potential implication of inwardly rectifying potassium (Kir) channels in epileptogenesis. Kir channels consist of seven different subfamilies (Kir1-Kir7), and they are highly expressed in both neuronal and glial cells in the central nervous system. These channels control the cell volume and excitability. In this review, we discuss preclinical and clinical evidence on the role of the several subfamilies of Kir channels in epileptogenesis, aiming to shed more light on the pathogenesis of this disorder and pave the way for future novel therapeutic approaches.
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Affiliation(s)
- Enes Akyuz
- Faculty of International Medicine, Department of Biophysics, University of Health Sciences, Istanbul, Turkey
| | - Betul Koklu
- Faculty of Medicine, Namık Kemal University, Tekirdağ, Turkey
| | - Arda Uner
- Faculty of Medicine, Yozgat Bozok University, Yozgat, Turkey
| | - Efthalia Angelopoulou
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Yam Nath Paudel
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Malaysia
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Zhang M, Li B, Liu Y, Tang R, Lang Y, Huang Q, He J. Different Modes of Low-Frequency Focused Ultrasound-Mediated Attenuation of Epilepsy Based on the Topological Theory. MICROMACHINES 2021; 12:mi12081001. [PMID: 34442623 PMCID: PMC8399944 DOI: 10.3390/mi12081001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 08/19/2021] [Accepted: 08/19/2021] [Indexed: 01/17/2023]
Abstract
Epilepsy is common brain dysfunction, where abnormal synchronized activities can be observed across multiple brain regions. Low-frequency focused pulsed ultrasound has been proven to modulate the epileptic brain network. In this study, we used two modes of low-intensity focused ultrasound (pulsed-wave and continuous-wave) to sonicate the brains of KA-induced epileptic rats, analyzed the EEG functional brain connections to explore their respective effect on the epileptic brain network, and discuss the mechanism of ultrasound neuromodulation. By comparing the brain network characteristics before and after sonication, we found that two modes of ultrasound both significantly affected the functional brain network, especially in the low-frequency band below 12 Hz. After two modes of sonication, the power spectral density of the EEG signals and the connection strength of the brain network were significantly reduced, but there was no significant difference between the two modes. Our results indicated that the ultrasound neuromodulation could effectively regulate the epileptic brain connections. The ultrasound-mediated attenuation of epilepsy was independent of modes of ultrasound.
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Affiliation(s)
- Minjian Zhang
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China; (M.Z.); (B.L.); (Y.L.); (Q.H.)
| | - Bo Li
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China; (M.Z.); (B.L.); (Y.L.); (Q.H.)
| | - Yafei Liu
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China; (M.Z.); (B.L.); (Y.L.); (Q.H.)
| | - Rongyu Tang
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (R.T.); (Y.L.)
| | - Yiran Lang
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (R.T.); (Y.L.)
| | - Qiang Huang
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China; (M.Z.); (B.L.); (Y.L.); (Q.H.)
| | - Jiping He
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China; (M.Z.); (B.L.); (Y.L.); (Q.H.)
- Correspondence: ; Tel.: +86-010-68917396
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Nonperiodic stimulation for the treatment of refractory epilepsy: Applications, mechanisms, and novel insights. Epilepsy Behav 2021; 121:106609. [PMID: 31704250 DOI: 10.1016/j.yebeh.2019.106609] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 10/14/2019] [Accepted: 10/14/2019] [Indexed: 11/21/2022]
Abstract
Electrical stimulation of the central nervous system is a promising alternative for the treatment of pharmacoresistant epilepsy. Successful clinical and experimental stimulation is most usually carried out as continuous trains of current or voltage pulses fired at rates of 100 Hz or above, since lower frequencies yield controversial results. On the other hand, stimulation frequency should be as low as possible, in order to maximize implant safety and battery efficiency. Moreover, the development of stimulation approaches has been largely empirical in general, while they should be engineered with the neurobiology of epilepsy in mind if a more robust, efficient, efficacious, and safe application is intended. In an attempt to reconcile evidence of therapeutic effect with the understanding of the underpinnings of epilepsy, our group has developed a nonstandard form of low-frequency stimulation with randomized interpulse intervals termed nonperiodic stimulation (NPS). The rationale was that an irregular temporal pattern would impair neural hypersynchronization, which is a hallmark of epilepsy. In this review, we start by briefly revisiting the literature on the molecular, cellular, and network level mechanisms of epileptic phenomena in order to highlight this often-overlooked emergent property of cardinal importance in the pathophysiology of the disease. We then review our own studies on the efficacy of NPS against acute and chronic experimental seizures and also on the anatomical and physiological mechanism of the method, paying special attention to the hypothesis that the lack of temporal regularity induces desynchronization. We also put forward a novel insight regarding the temporal structure of NPS that may better encompass the set of findings published by the group: the fact that intervals between stimulation pulses have a distribution that follows a power law and thus may induce natural-like activity that would compete with epileptiform discharge for the recruitment of networks. We end our discussion by mentioning ongoing research and future projects of our lab.
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Kalkan ÖF, Şahin Z, Öztürk H, Keser H, Aydın-Abidin S, Abidin İ. Phoenixin-14 reduces the frequency of interictal-like events in mice brain slices. Exp Brain Res 2021; 239:2841-2849. [PMID: 34283252 DOI: 10.1007/s00221-021-06179-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 07/13/2021] [Indexed: 01/17/2023]
Abstract
Phoenixin-14 (PNX-14) has a wide bioactivity in the central nervous system. Its role in the hypothalamus has been investigated, and it has been reported that it is involved in the regulation of excitability in hypothalamic neurons. However, its role in the regulation of excitability in entorhinal cortex and the hippocampus is unknown. In this study, we investigated whether i. PNX-14 induces any synchronous discharges or epileptiform activity and ii. PNX-14 has any effect on already initiated epileptiform discharges. We used 350 µm thick acute horizontal hippocampal-entorhinal cortex slices obtained from 30- to 35-day-old mice. Extracellular field potential recordings were evaluated in the entorhinal cortex and hippocampus CA1 region. Bath application of PNX-14 did not initiate any epileptiform activity or abnormal discharges. 4-Aminopyridine was applied to induce epileptiform activity in the slices. We found that 200 nM PNX-14 reduced the frequency of interictal-like events in both the entorhinal cortex and hippocampus CA1 region which was induced by 4-aminopyridine. Furthermore, PNX-14 led to a similar suppression in the total power of local field potentials of 1-120 Hz. The frequency or the duration of the ictal events was not affected. These results exhibited for the first time that PNX-14 has a modulatory effect on synchronized neuronal discharges which should be considered in future therapeutic approaches.
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Affiliation(s)
- Ömer Faruk Kalkan
- Department of Physiology, Faculty of Medicine, Karadeniz Technical University, 61080, Trabzon, Turkey.
| | - Zafer Şahin
- Department of Physiology, Faculty of Medicine, Karadeniz Technical University, 61080, Trabzon, Turkey
| | - Hilal Öztürk
- Department of Physiology, Faculty of Medicine, Karadeniz Technical University, 61080, Trabzon, Turkey
| | - Hatice Keser
- Department of Physiology, Faculty of Medicine, Karadeniz Technical University, 61080, Trabzon, Turkey
| | - Selcen Aydın-Abidin
- Department of Physiology, Faculty of Medicine, Karadeniz Technical University, 61080, Trabzon, Turkey
| | - İsmail Abidin
- Department of Physiology, Faculty of Medicine, Karadeniz Technical University, 61080, Trabzon, Turkey
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Erdogan A, Erdogan MA, Atasoy O, Erbas O. Effects of the Calcium Channel Blocker Otilonium Bromide on Seizure Activity in Rats With Pentylenetetrazole-Induced Convulsions. Neurochem Res 2021; 46:1717-1724. [PMID: 33811624 DOI: 10.1007/s11064-021-03310-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 03/16/2021] [Accepted: 03/20/2021] [Indexed: 10/21/2022]
Abstract
Millions of people suffer from drug-resistant epilepsy. New therapeutic approaches for removing this life-affecting disease are required. The activation of T-type calcium channels (TTCC) is one of the epileptogenesis mechanisms that cause epilepsy. So, we researched the effects of Otilonium bromide (OB), an antisposmolytic drug that inhibits TTCC, on seizure activity in rats with pentylenetetrazol (PTZ) induced convulsion. Randomly, 48 rats were divided into two groups; for electroencephalography (EEG) recordings and for behavioral assesment. Rats were treated with either intraperitoneal (IP) OB at two separate doses (25 mg/kg and 50 mg/kg) or placebo, and then pentylenetetrazole (IP), a potent seizure-inducing chemical administered to them. In our model we have measured rat seizure activity with EEG, the convulsion scala of Racine (RCS), the time of first myoclonic jerk (FMJ) and MDA levels to assess if OB has antiepileptic properties. The mean EEG spike wave percentage score reduced from 79.5% (placebo) to 59.2% (lower-dose) and 35.2% (higher-dose). FMJ had increased from a mean of 67.2 s (placebo), to 105.2 (lower-dose), 150.6 (higher-dose). RCS reduced from a mean of 5.12 (placebo) to 4.4 (lower-dose), 3.8 (higher-dose). MDA leves reduced from 84.5 nmol/gr to 51.09 nmol/gr (lower-dose), 33.2 nmol/gr (higher-dose). Compared to placebo, OB reduced significantly seizure activity at both doses, probably through blocking T-type calcium channels. All these results were statistically significant with < 0.0001 p-values. Otilonium bromide reduced seizure activity in rats with PTZ-induced convulsion. Therefore, the clinical role of OB and other TTCC inhibitors as potential anti-seizure drugs should be further investigated.
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Affiliation(s)
- Arife Erdogan
- Department of Emergency Medicine, Izmir Cigli Regional Training Hospital, Izmir, Turkey.
| | - Mumin Alper Erdogan
- Department of Physiology, Faculty of Medicine, Izmir Katip Celebi University, Izmir, Turkey
| | - Ozum Atasoy
- Department of Radiation Oncology, Istanbul Kartal Dr. Lutfı Kırdar Educatıon and Research Hospıtal, Istanbul, Turkey
| | - Oytun Erbas
- Faculty of Medicine, Department of Physiology, Demiroğlu Bilim University, Istanbul, Turkey
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Núñez-Ochoa MA, Chiprés-Tinajero GA, González-Domínguez NP, Medina-Ceja L. Causal relationship of CA3 back-projection to the dentate gyrus and its role in CA1 fast ripple generation. BMC Neurosci 2021; 22:37. [PMID: 34001031 PMCID: PMC8130286 DOI: 10.1186/s12868-021-00641-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 05/07/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Pathophysiological evidence from temporal lobe epilepsy models highlights the hippocampus as the most affected structure due to its high degree of neuroplasticity and control of the dynamics of limbic structures, which are necessary to encode information, conferring to it an intrinsic epileptogenicity. A loss in this control results in observable oscillatory perturbations called fast ripples, in epileptic rats those events are found in CA1, CA3, and the dentate gyrus (DG), which are the principal regions of the trisynaptic circuit of the hippocampus. The present work used Granger causality to address which relationships among these three regions of the trisynaptic circuit are needed to cause fast ripples in CA1 in an in vivo model. For these purposes, male Wistar rats (210-300 g) were injected with a single dose of pilocarpine hydrochloride (2.4 mg/2 µl) into the right lateral ventricle and video-monitored 24 h/day to detect spontaneous and recurrent seizures. Once detected, rats were implanted with microelectrodes in these regions (fixed-recording tungsten wire electrodes, 60-μm outer diameter) ipsilateral to the pilocarpine injection. A total of 336 fast ripples were recorded and probabilistically characterized, from those fast ripples we made a subset of all the fast ripple events associated with sharp-waves in CA1 region (n = 40) to analyze them with Granger Causality. RESULTS Our results support existing evidence in vitro in which fast ripple events in CA1 are initiated by CA3 multiunit activity and describe a general synchronization in the theta band across the three regions analyzed DG, CA3, and CA1, just before the fast ripple event in CA1 have begun. CONCLUSION This in vivo study highlights the causal participation of the CA3 back-projection to the DG, a connection commonly overlooked in the trisynaptic circuit, as a facilitator of a closed-loop among these regions that prolongs the excitatory activity of CA3. We speculate that the loss of inhibitory drive of DG and the mechanisms of ripple-related memory consolidation in which also the CA3 back-projection to DG has a fundamental role might be underlying processes of the fast ripples generation in CA1.
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Affiliation(s)
- Miguel A Núñez-Ochoa
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico
- Biomedical Sciences, CUCS, University of Guadalajara, Sierra Mojada 950, Colonia Independencia, CP 44340, Guadalajara, Jalisco, Mexico
| | - Gustavo A Chiprés-Tinajero
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico
- Biomedical Sciences, CUCS, University of Guadalajara, Sierra Mojada 950, Colonia Independencia, CP 44340, Guadalajara, Jalisco, Mexico
| | - Nadia P González-Domínguez
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico
| | - Laura Medina-Ceja
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Camino Ing. R. Padilla Sánchez 2100, Las Agujas, Nextipac, CP 45110, Zapopan, Jalisco, Mexico.
- Biomedical Sciences, CUCS, University of Guadalajara, Sierra Mojada 950, Colonia Independencia, CP 44340, Guadalajara, Jalisco, Mexico.
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Park HJ, Kim HN, Kim CY, Seo MD, Baek SH. Synergistic Protection by Isoquercitrin and Quercetin against Glutamate-Induced Oxidative Cell Death in HT22 Cells via Activating Nrf2 and HO-1 Signaling Pathway: Neuroprotective Principles and Mechanisms of Dendropanax morbifera Leaves. Antioxidants (Basel) 2021; 10:antiox10040554. [PMID: 33918248 PMCID: PMC8066007 DOI: 10.3390/antiox10040554] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/28/2021] [Accepted: 03/31/2021] [Indexed: 01/18/2023] Open
Abstract
Dendropanax morbifera leaves (DML) have long been used as traditional medicine to treat diverse symptoms in Korea. Ethyl acetate-soluble extracts of DML (DMLE) rescued HT22 mouse hippocampal neuronal cells from glutamate (Glu)-induced oxidative cell death; however, the protective compounds and mechanisms remain unknown. Here, we aimed to identify the neuroprotective ingredients and mechanisms of DMLE in the Glu-HT22 cell model. Five antioxidant compounds were isolated from DMLE and characterized as chlorogenic acid, hyperoside, isoquercitrin, quercetin, and rutin by spectroscopic methods. Isoquercitrin and quercetin significantly inhibited Glu-induced oxidative cell death by restoring intracellular reactive oxygen species (ROS) levels and mitochondrial superoxide generation, Ca2+ dysregulation, mitochondrial dysfunction, and nuclear translocation of apoptosis-inducing factor. These two compounds significantly increased the expression levels of nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in the presence or absence of Glu treatment. Combinatorial treatment of the five compounds based on the equivalent concentrations in DMLE showed that significant protection was found only in the cells cotreated with isoquercitrin and quercetin, both of whom showed prominent synergism, as assessed by drug–drug interaction analysis. These findings suggest that isoquercitrin and quercetin are the active principles representing the protective effects of DMLE, and these effects were mediated by the Nrf2/HO-1 pathway.
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Affiliation(s)
- Hye-Jin Park
- College of Pharmacy and Research Institute of Pharmaceutical Science and Technology (RIPST), Ajou University, Suwon 16499, Korea; (H.-J.P.); (H.-N.K.)
| | - Ha-Neul Kim
- College of Pharmacy and Research Institute of Pharmaceutical Science and Technology (RIPST), Ajou University, Suwon 16499, Korea; (H.-J.P.); (H.-N.K.)
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
| | - Chul Young Kim
- College of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan-si 15588, Korea;
| | - Min-Duk Seo
- College of Pharmacy and Research Institute of Pharmaceutical Science and Technology (RIPST), Ajou University, Suwon 16499, Korea; (H.-J.P.); (H.-N.K.)
- Department of Molecular Science and Technology, Ajou University, Suwon 16499, Korea
- Correspondence: (M.-D.S.); (S.-H.B.)
| | - Seung-Hoon Baek
- College of Pharmacy and Research Institute of Pharmaceutical Science and Technology (RIPST), Ajou University, Suwon 16499, Korea; (H.-J.P.); (H.-N.K.)
- Correspondence: (M.-D.S.); (S.-H.B.)
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Schlabitz S, Monni L, Ragot A, Dipper-Wawra M, Onken J, Holtkamp M, Fidzinski P. Spatiotemporal Correlation of Epileptiform Activity and Gene Expression in vitro. Front Mol Neurosci 2021; 14:643763. [PMID: 33859552 PMCID: PMC8042243 DOI: 10.3389/fnmol.2021.643763] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/03/2021] [Indexed: 11/14/2022] Open
Abstract
Epileptiform activity alters gene expression in the central nervous system, a phenomenon that has been studied extensively in animal models. Here, we asked whether also in vitro models of seizures are in principle suitable to investigate changes in gene expression due to epileptiform activity and tested this hypothesis mainly in rodent and additionally in some human brain slices. We focused on three genes relevant for seizures and epilepsy: FOS proto-oncogene (c-Fos), inducible cAMP early repressor (Icer) and mammalian target of rapamycin (mTor). Seizure-like events (SLEs) were induced by 4-aminopyridine (4-AP) in rat entorhinal-hippocampal slices and by 4-AP/8 mM potassium in human temporal lobe slices obtained from surgical treatment of epilepsy. SLEs were monitored simultaneously by extracellular field potentials and intrinsic optical signals (IOS) for 1–4 h, mRNA expression was quantified by real time PCR. In rat slices, both duration of SLE exposure and SLE onset region were associated with increased expression of c-Fos and Icer while no such association was shown for mTor expression. Similar to rat slices, c-FOS induction in human tissue was increased in slices with epileptiform activity. Our results indicate that irrespective of limitations imposed by ex vivo conditions, in vitro models represent a suitable tool to investigate gene expression. Our finding is of relevance for the investigation of human tissue that can only be performed ex vivo. Specifically, it presents an important prerequisite for future studies on transcriptome-wide and cell-specific changes in human tissue with the goal to reveal novel candidates involved in the pathophysiology of epilepsy and possibly other CNS pathologies.
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Affiliation(s)
- Sophie Schlabitz
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany
| | - Laura Monni
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany
| | - Alienor Ragot
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany
| | - Matthias Dipper-Wawra
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany
| | - Julia Onken
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurosurgery, Berlin, Germany
| | - Martin Holtkamp
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany.,Epilepsy-Center Berlin-Brandenburg, Institute for Diagnostics of Epilepsy, Berlin, Germany
| | - Pawel Fidzinski
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Neurology with Experimental Neurology, Clinical and Experimental Epileptology, Berlin, Germany.,Epilepsy-Center Berlin-Brandenburg, Institute for Diagnostics of Epilepsy, Berlin, Germany.,Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, NeuroCure Cluster of Excellence, Neuroscience Research Center, Berlin, Germany
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Modulation in time of the interictal spiking pattern related to epileptic seizures. Clin Neurophysiol 2021; 132:1083-1088. [PMID: 33770591 DOI: 10.1016/j.clinph.2021.01.026] [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: 08/29/2020] [Revised: 12/07/2020] [Accepted: 01/07/2021] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To test the hypothesis that significant changes in the occurrence of interictal epileptiform electroencephalography (EEG) discharges (EDs) are associated with seizures: while some EDs are pro-convulsive, increasing at seizure-occurrence, others are protective, showing decrease related to seizures. METHODS We analyzed 102 consecutive, long-term video-EEG monitoring sessions, from 98 patients. Using a semi-automated spike-detection method, we quantified the occurrence of EDs, grouped according to their location and morphology (clusters) and we constructed graphical representation of data, showing changes in time of the spiking patterns (spike-histograms). We compared the spike-histograms with the time-points of the seizures (pre-, peri- and postictal changes). RESULTS Totally 179 ED-clusters were identified. Modulation of the spiking pattern, associated with seizures, was observed in 66 clusters (37%), from 47 patients (48%). Most of these changes (40 clusters; 61%) were related to increase in the spiking-pattern. CONCLUSIONS Changes in spiking-pattern were associated with more than one third of the EDs. Both increasing and decreasing patterns were observed. SIGNIFICANCE EDs are more often pro-convulsive, with increasing spiking patterns associated with seizures. However, in more than one third of the ED clusters modulated by seizures, the spiking pattern decreased, raising the possibility of an anticonvulsive function of these discharges.
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Janković SM, Dješević M, Janković SV. Experimental GABA A Receptor Agonists and Allosteric Modulators for the Treatment of Focal Epilepsy. J Exp Pharmacol 2021; 13:235-244. [PMID: 33727865 PMCID: PMC7954424 DOI: 10.2147/jep.s242964] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/23/2021] [Indexed: 12/16/2022] Open
Abstract
GABA A receptors are ubiquitous in the central nervous system and there is a huge diversity of receptor subtypes in almost all regions of the brain. However, the expression of GABA A receptor subtypes is altered in both the gray and white matter of patients with focal epilepsy. Although there is a number of anticonvulsants with marketing authorization for the treatment of focal epilepsy which act through GABA A receptors, potentiating the inhibitory effects of GABA, it is necessary to develop more potent and more specific GABAergic anticonvulsants that are effective in drug-resistant patients with focal epilepsy. There are three orthosteric and at least seven allosteric agonist binding sites at the GABA A receptor. In experimental and clinical studies, full agonists of GABA A receptors showed a tendency to cause desensitization of the receptors, tolerance, and physical dependence; therefore, partial orthosteric agonists and positive allosteric modulators of GABA A receptors were further developed. Preclinical studies demonstrated the anticonvulsant efficacy of positive allosteric modulators with selective action on GABA A receptors with α2/α3 subunits, but only a handful of them were further tested in clinical trials. The best results were obtained for clobazam (already marketed), ganaxolone (in phase III trials), CVL-865 (in phase II trials), and padsevonil (in phase III trials). Several compounds with more selective action on GABA A receptors, perhaps only in certain brain regions, have the potential to become effective drugs against specific subtypes of focal-onset epilepsy. However, their development needs time, and in the near future we can expect only one or two new GABA A agonists to obtain marketing authorization for focal epilepsy, an advance that would be of use for just a fraction of patients with drug-resistant epilepsy.
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Affiliation(s)
| | - Miralem Dješević
- Cardiology Department, Private Policlinic Center Eurofarm, Sarajevo, Bosnia and Hercegovina
| | - Snežana V Janković
- Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
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Núñez-Ochoa MA, Chiprés-Tinajero GA, Medina-Ceja L. Evaluation of the hippocampal immunoreactivity of the serotonin 5-HT1A, 5-HT2 and 5-HT7 receptors in a pilocarpine temporal lobe epilepsy rat model with fast ripples. Neuroreport 2021; 32:306-311. [PMID: 33470771 DOI: 10.1097/wnr.0000000000001594] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Fast ripples (FRs) are found in the hippocampus of epileptic brains, and this fast electrical activity has been described as a biomarker of the epileptogenic process itself. Results from our laboratory, such as the observation of decreased seizure rates and FR incidence at a specific citalopram dose, have suggested that serotonin (5-HT) may play a key role in the FR generation process. Therefore, to gather more details about the state of the serotoninergic system in the hippocampus under an epileptogenic process, we studied the immunoreactivity of three 5-HT receptors (5-HT1A, 5-HT2 and 5-HT7) as well as the extracellular levels of 5-HT in the hippocampal tissue of epileptic rats with FR. Wistar rats (210-300 g) were injected with a single dose of pilocarpine hydrochloride (2.4 mg/2 µl) in the right lateral ventricle and video-monitored 24 h/d to detect spontaneous and recurrent seizures; microelectrodes were implanted in the dentate gyrus (DG) and CA3 and CA1 regions of these rats ipsilateral to the pilocarpine injection site 1 day after the first spontaneous seizure was observed, and only rats who suffered FR events were used in this work. Thirty-three days after the first spontaneous seizure, an immunostaining procedure and high performance liquid chromatography were performed to measure the 5-HT levels. A general depletion of the 5-HT and 5-HIIA levels in hippocampal tissue from epileptic animals compared with those in controls was observed; in addition, a general decrease in immunoreactivity for the three receptors was found, especially in the DG, which may support the establishment of an excitatory/inhibitory imbalance in the trisynaptic circuit that underlies the FR generation process.
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MESH Headings
- Animals
- CA1 Region, Hippocampal/drug effects
- CA1 Region, Hippocampal/metabolism
- CA3 Region, Hippocampal/drug effects
- CA3 Region, Hippocampal/metabolism
- Dentate Gyrus/drug effects
- Dentate Gyrus/metabolism
- Disease Models, Animal
- Epilepsy, Temporal Lobe/chemically induced
- Epilepsy, Temporal Lobe/metabolism
- Hippocampus/drug effects
- Hippocampus/metabolism
- Hydroxyindoleacetic Acid/metabolism
- Immunohistochemistry
- Muscarinic Agonists/toxicity
- Pilocarpine/toxicity
- Rats
- Receptor, Serotonin, 5-HT1A/drug effects
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptors, Serotonin/drug effects
- Receptors, Serotonin/metabolism
- Receptors, Serotonin, 5-HT2/drug effects
- Receptors, Serotonin, 5-HT2/metabolism
- Serotonin/metabolism
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Affiliation(s)
- Miguel A Núñez-Ochoa
- Laboratory of Neurophysiology, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Jalisco, México
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Lazzarotto G, Klippel Zanona Q, Cagliari Zenki K, Calcagnotto ME. Effect of Memantine on Pentylenetetrazol-induced Seizures and EEG Profile in Animal Model of Cortical Malformation. Neuroscience 2021; 457:114-124. [PMID: 33465407 DOI: 10.1016/j.neuroscience.2020.12.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/27/2020] [Accepted: 12/31/2020] [Indexed: 11/28/2022]
Abstract
Developmental cortical malformations (DCM) are one of the main causes of refractory epilepsy. Many are the mechanisms underlying the hyperexcitability in DCM, including the important contribution of N-methyl-D-aspartate receptors (NMDAR). NMDAR blockers are shown to abolish seizures and epileptiform activity. Memantine, a NMDAR antagonist used to treat Alzheimeŕs disease, has been recently investigated as a possible treatment for other neurological disorders. However, the effects on preventing or diminishing seizures are controversial. Here we aimed to evaluate the effects of memantine on pentylenetetrazole (PTZ)-induced seizures in the freeze-lesion (FL) model. Bilateral cortical microgyria were induced (FL) or not (Sham) in male Wistar neonate rats. At P30, subdural electrodes were implanted and 7 days later, video-EEG was recorded in animals receiving either memantine (FL-M or Sham-M) or saline (FL-S or Sham-S), followed by PTZ. Seizures were evaluated by video-EEG during one hour and scored according to Racine scale. The video-EEG analyses revealed that the number of seizures and the total duration of stage IV-V seizures developed during the 1 h-period increased after memantine application in all groups. The EEG power spectral density (PSD) analysis showed an increased PSD of pre-ictal delta in Sham-M animals and increased PSD of slow, middle and fast gamma oscillations after memantine injection that persists during the pre-ictal period in all groups. Our findings suggested that memantine was unable to control the PTZ-induced seizures and that the associated enhancement of PSD of gamma oscillations may contribute to the increased probability of seizure development in these animals.
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Affiliation(s)
- Gabriela Lazzarotto
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory (NNNESP Lab.), Department of Biochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Querusche Klippel Zanona
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory (NNNESP Lab.), Department of Biochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Kamila Cagliari Zenki
- Graduate Program in Biological Sciences: Biochemistry, Department of Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Maria Elisa Calcagnotto
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory (NNNESP Lab.), Department of Biochemistry, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; Graduate Program in Neuroscience, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Biological Sciences: Biochemistry, Department of Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Anticonvulsant effect of pterostilbene and its influence on the anxiety- and depression-like behavior in the pentetrazol-kindled mice: behavioral, biochemical, and molecular studies. Psychopharmacology (Berl) 2021; 238:3167-3181. [PMID: 34333674 PMCID: PMC8605980 DOI: 10.1007/s00213-021-05933-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/08/2021] [Indexed: 01/03/2023]
Abstract
RATIONALE Pterostilbene is the 3,5-dimethoxy derivative of resveratrol with numerous beneficial effects including neuroprotective properties. Experimental studies revealed its anticonvulsant action in the acute seizure tests. OBJECTIVES The purpose of the present study was to evaluate the effect of pterostilbene in the pentetrazol (PTZ)-induced kindling model of epilepsy in mice as well as to assess some possible mechanisms of its anticonvulsant action in this model. METHODS Mice were repeatedly treated with pterostilbene (50-200 mg/kg) and its effect on the development of seizure activity in the PTZ kindling was estimated. Influence of pterostilbene on the locomotor activity and anxiety- and depression-like behavior in the PTZ-kindled mice was also assessed. To understand the possible mechanisms of anticonvulsant activity of pterostilbene, γ-aminobutyric acid (GABA) and glutamate concentrations in the prefrontal cortex and hippocampus of the PTZ-kindled mice were measured using LC-MS/MS method. Moreover, mRNA expression of BDNF, TNF-α, IL-1β, IL-6, GABRA1A, and GRIN2B was determined by RT-qPCR technique. RESULTS We found that pterostilbene at a dose of 200 mg/kg considerably reduced seizure activity but did not influence the locomotor activity and depression- and anxiety-like behavior in the PTZ-kindled mice. In the prefrontal cortex and hippocampus, pterostilbene reversed the kindling-induced decrease of GABA concentration. Neither in the prefrontal cortex nor hippocampus pterostilbene affected mRNA expression of IL-1β, IL-6, GABRA1A, and GRIN2B augmented by PTZ kindling. Pterostilbene at a dose of 100 mg/kg significantly decreased BDNF and TNF-α mRNA expression in the hippocampus of the PTZ-kindled mice. CONCLUSIONS Although further studies are necessary to understand the mechanism of anticonvulsant properties of pterostilbene, our findings suggest that it might be considered a candidate for a new antiseizure drug.
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Hao J, Cui Y, Niu B, Yu L, Lin Y, Xia Y, Yao D, Guo D. Roles of Very Fast Ripple (500-1000[Formula: see text]Hz) in the Hippocampal Network During Status Epilepticus. Int J Neural Syst 2020; 31:2150002. [PMID: 33357153 DOI: 10.1142/s0129065721500027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Very fast ripples (VFRs, 500-1000[Formula: see text]Hz) are considered more specific than high-frequency oscillations (80-500[Formula: see text]Hz) as biomarkers of epileptogenic zones. Although VFRs are frequent abnormal phenomena in epileptic seizures, their functional roles remain unclear. Here, we detected the VFRs in the hippocampal network and tracked their roles during status epilepticus (SE) in rats with pilocarpine-induced temporal lobe epilepsy (TLE). All regions in the hippocampal network exhibited VFRs in the baseline, preictal, ictal and postictal states, with the ictal state containing the most VFRs. Moreover, strong phase-locking couplings existed between VFRs and slow oscillations (1-12[Formula: see text]Hz) in the ictal and postictal states for all regions. Further investigation indicated that during VFRs, the build-up of slow oscillations in the ictal state began from the temporal lobe and then spread through the whole hippocampal network via two different pathways, which might be associated with the underlying propagation of epileptiform discharges in the hippocampal network. Overall, we provide a functional description of the emergence of VFRs in the hippocampal network during SE, and we also establish that VFRs may be the physiological representation of the pathological alterations in hippocampal network activity during SE in TLE.
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Affiliation(s)
- Jianmin Hao
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for NeuroInformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic, Science and Technology of China, Chengdu Sichuan 611731, P. R. China
| | - Yan Cui
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for NeuroInformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic, Science and Technology of China, Chengdu Sichuan 611731, P. R. China
| | - Bochao Niu
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for NeuroInformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic, Science and Technology of China, Chengdu Sichuan 611731, P. R. China
| | - Liang Yu
- Department of Neurology, Sichuan Academy of Medical, Sciences and Sichuan Provincial People's Hospital, Chengdu Sichuan, P. R. China
| | - Yuhang Lin
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for NeuroInformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic, Science and Technology of China, Chengdu Sichuan 611731, P. R. China
| | - Yang Xia
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for NeuroInformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic, Science and Technology of China, Chengdu Sichuan 611731, P. R. China
| | - Dezhong Yao
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for NeuroInformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic, Science and Technology of China, Chengdu Sichuan 611731, P. R. China.,School of Electrical Engineering, Zhengzhou University, Zhengzhou, Henan 450001, P. R. China
| | - Daqing Guo
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for NeuroInformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic, Science and Technology of China, Chengdu Sichuan 611731, P. R. China
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Lévesque M, Biagini G, Avoli M. Neurosteroids and Focal Epileptic Disorders. Int J Mol Sci 2020; 21:ijms21249391. [PMID: 33321734 PMCID: PMC7763947 DOI: 10.3390/ijms21249391] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/27/2020] [Accepted: 12/08/2020] [Indexed: 11/18/2022] Open
Abstract
Neurosteroids are a family of compounds that are synthesized in principal excitatory neurons and glial cells, and derive from the transformation of cholesterol into pregnenolone. The most studied neurosteroids—allopregnanolone and allotetrahydrodeoxycorticosterone (THDOC)—are known to modulate GABAA receptor-mediated transmission, thus playing a role in controlling neuronal network excitability. Given the role of GABAA signaling in epileptic disorders, neurosteroids have profound effects on seizure generation and play a role in the development of chronic epileptic conditions (i.e., epileptogenesis). We review here studies showing the effects induced by neurosteroids on epileptiform synchronization in in vitro brain slices, on epileptic activity in in vivo models, i.e., in animals that were made epileptic with chemoconvulsant treatment, and in epileptic patients. These studies reveal that neurosteroids can modulate ictogenesis and the occurrence of pathological network activity such as interictal spikes and high-frequency oscillations (80–500 Hz). Moreover, they can delay the onset of spontaneous seizures in animal models of mesial temporal lobe epilepsy. Overall, this evidence suggests that neurosteroids represent a new target for the treatment of focal epileptic disorders.
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Affiliation(s)
- Maxime Lévesque
- Montreal Neurological Institute-Hospital & Department of Neurology and Neurosurgery, 3801 University Street, Montreal, QC H3A 2B4, Canada;
- Correspondence: ; Tel.: +1-514-398-8909
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Università 4, 41121 Modena, Italy;
| | - Massimo Avoli
- Montreal Neurological Institute-Hospital & Department of Neurology and Neurosurgery, 3801 University Street, Montreal, QC H3A 2B4, Canada;
- Department of Physiology, McGill University, Montreal, QC H3A 2B4, Canada
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Akeret K, Stumpo V, Staartjes VE, Vasella F, Velz J, Marinoni F, Dufour JP, Imbach LL, Regli L, Serra C, Krayenbühl N. Topographic brain tumor anatomy drives seizure risk and enables machine learning based prediction. Neuroimage Clin 2020; 28:102506. [PMID: 33395995 PMCID: PMC7711280 DOI: 10.1016/j.nicl.2020.102506] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/05/2020] [Accepted: 11/10/2020] [Indexed: 12/17/2022]
Abstract
OBJECTIVE The aim of this study was to identify relevant risk factors for epileptic seizures upon initial diagnosis of a brain tumor and to develop and validate a machine learning based prediction to allow for a tailored risk-based antiepileptic therapy. METHODS Clinical, electrophysiological and high-resolution imaging data was obtained from a consecutive cohort of 1051 patients with newly diagnosed brain tumors. Factor-associated seizure risk difference allowed to determine the relevance of specific topographic, demographic and histopathologic variables available at the time of diagnosis for seizure risk. The data was divided in a 70/30 ratio into a training and test set. Different machine learning based predictive models were evaluated before a generalized additive model (GAM) was selected considering its traceability while maintaining high performance. Based on a clinical stratification of the risk factors, three different GAM were trained and internally validated. RESULTS A total of 923 patients had full data and were included. Specific topographic anatomical patterns that drive seizure risk could be identified. The involvement of allopallial, mesopallial or primary motor/somatosensory neopallial structures by brain tumors results in a significant and clinically relevant increase in seizure risk. While topographic input was most relevant for the GAM, the best prediction was achieved by a combination of topographic, demographic and histopathologic information (Validation: AUC: 0.79, Accuracy: 0.72, Sensitivity: 0.81, Specificity: 0.66). CONCLUSIONS This study identifies specific phylogenetic anatomical patterns as epileptic drivers. A GAM allowed the prediction of seizure risk using topographic, demographic and histopathologic data achieving fair performance while maintaining transparency.
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Affiliation(s)
- Kevin Akeret
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Vittorio Stumpo
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland; Institute of Neurosurgery, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Victor E Staartjes
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland; Amsterdam UMC, Vrije Universiteit Amsterdam, Neurosurgery, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - Flavio Vasella
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Julia Velz
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Federica Marinoni
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Jean-Philippe Dufour
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Lukas L Imbach
- Division of Epileptology, Department of Neurology, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Luca Regli
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Carlo Serra
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Niklaus Krayenbühl
- Department of Neurosurgery, Clinical Neuroscience Center, University Hospital Zurich, University of Zurich, Zurich, Switzerland; Division of Pediatric Neurosurgery, University Children's Hospital, Zurich, Switzerland
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47
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Medeiros DDC, Cota VR, Oliveira ACP, Moreira FA, Moraes MFD. The Endocannabinoid System Activation as a Neural Network Desynchronizing Mediator for Seizure Suppression. Front Behav Neurosci 2020; 14:603245. [PMID: 33281577 PMCID: PMC7691588 DOI: 10.3389/fnbeh.2020.603245] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 10/20/2020] [Indexed: 01/08/2023] Open
Abstract
The understanding that hyper-excitability and hyper-synchronism in epilepsy are indissociably bound by a cause-consequence relation has only recently been challenged. Thus, therapeutic strategies for seizure suppression have often aimed at inhibiting excitatory circuits and/or activating inhibitory ones. However, new approaches that aim to desynchronize networks or compromise abnormal coupling between adjacent neural circuitry have been proven effective, even at the cost of enhancing local neuronal activation. Although most of these novel perspectives targeting circuitry desynchronization and network coupling have been implemented by non-pharmacological devices, we argue that there may be endogenous neurochemical systems that act primarily in the desynchronization component of network behavior rather than dampening excitability of individual neurons. This review explores the endocannabinoid system as one such possible pharmacological landmark for mimicking a form of "on-demand" desynchronization analogous to those proposed by deep brain stimulation in the treatment of epilepsy. This essay discusses the evidence supporting the role of the endocannabinoid system in modulating the synchronization and/or coupling of distinct local neural circuitry; which presents obvious implications on the physiological setting of proper sensory-motor integration. Accordingly, the process of ictogenesis involves pathological circuit coupling that could be avoided, or at least have its spread throughout the containment of other areas, if such endogenous mechanisms of control could be activated or potentiated by pharmacological intervention. In addition, we will discuss evidence that supports not only a weaker role played on neuronal excitability but the potential of the endocannabinoid system strengthening its modulatory effect, only when circuitry coupling surpasses a level of activation.
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Affiliation(s)
- Daniel de Castro Medeiros
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Vinícius Rosa Cota
- Laboratório Interdisciplinar de Neuroengenharia e Neurociências, Departamento de Engenharia Elétrica, Universidade Federal de São João Del-Rei, São João Del-Rei, Brazil
| | - Antonio Carlos P Oliveira
- Departamento de Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Fabricio A Moreira
- Departamento de Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Márcio Flávio Dutra Moraes
- Núcleo de Neurociências, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Centro de Tecnologia e Pesquisa em Magneto Ressonância, Programa de Pós-Graduação em Engenharia Elétrica, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Pons-Bennaceur A, Tsintsadze V, Bui TT, Tsintsadze T, Minlebaev M, Milh M, Scavarda D, Giniatullin R, Giniatullina R, Shityakov S, Wright M, Miller AD, Lozovaya N, Burnashev N. Diadenosine-Polyphosphate Analogue AppCH2ppA Suppresses Seizures by Enhancing Adenosine Signaling in the Cortex. Cereb Cortex 2020; 29:3778-3795. [PMID: 30295710 DOI: 10.1093/cercor/bhy257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 08/15/2018] [Accepted: 09/14/2018] [Indexed: 01/16/2023] Open
Abstract
Epilepsy is a multifactorial disorder associated with neuronal hyperexcitability that affects more than 1% of the human population. It has long been known that adenosine can reduce seizure generation in animal models of epilepsies. However, in addition to various side effects, the instability of adenosine has precluded its use as an anticonvulsant treatment. Here we report that a stable analogue of diadenosine-tetraphosphate: AppCH2ppA effectively suppresses spontaneous epileptiform activity in vitro and in vivo in a Tuberous Sclerosis Complex (TSC) mouse model (Tsc1+/-), and in postsurgery cortical samples from TSC human patients. These effects are mediated by enhanced adenosine signaling in the cortex post local neuronal adenosine release. The released adenosine induces A1 receptor-dependent activation of potassium channels thereby reducing neuronal excitability, temporal summation, and hypersynchronicity. AppCH2ppA does not cause any disturbances of the main vital autonomous functions of Tsc1+/- mice in vivo. Therefore, we propose this compound to be a potent new candidate for adenosine-related treatment strategies to suppress intractable epilepsies.
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Affiliation(s)
- Alexandre Pons-Bennaceur
- INSERM UMR1249, Mediterranean Institute of Neurobiology (INMED), Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Vera Tsintsadze
- INSERM UMR1249, Mediterranean Institute of Neurobiology (INMED), Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France.,Knight Cardiovascular Institute, Oregon Health and Science University, OR, USA
| | - Thi-Thien Bui
- B&A Therapeutics, Ben-Ari Institute of Neuroarcheology, Batiment Beret-Delaage, Zone Luminy Biotech Entreprises, Marseille, Cedex 09, France
| | - Timur Tsintsadze
- INSERM UMR1249, Mediterranean Institute of Neurobiology (INMED), Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Marat Minlebaev
- INSERM UMR1249, Mediterranean Institute of Neurobiology (INMED), Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France.,Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia
| | - Mathieu Milh
- APHM, Department of Pediatric Neurosurgery and Neurology, CHU Timone, Marseille Cedex 5, France
| | - Didier Scavarda
- APHM, Department of Pediatric Neurosurgery and Neurology, CHU Timone, Marseille Cedex 5, France
| | - Rashid Giniatullin
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia.,A.I. Virtanen Institute for Molecular Sciences, Department of Neurobiology, University of Eastern Finland, Kuopio, Finland
| | - Raisa Giniatullina
- A.I. Virtanen Institute for Molecular Sciences, Department of Neurobiology, University of Eastern Finland, Kuopio, Finland
| | - Sergey Shityakov
- Department of Anaesthesia and Critical Care, University of Würzburg, Josef-Schneider-Street 2, Würzburg, Germany
| | - Michael Wright
- School of Cancer and Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, Waterloo Campus, 150 Stamford Street, London, UK
| | - Andrew D Miller
- School of Cancer and Pharmaceutical Sciences, King's College London, Franklin-Wilkins Building, Waterloo Campus, 150 Stamford Street, London, UK.,Veterinary Research Institute, Hudcova 296/70, Brno, Czech Republic.,KP Therapeutics Ltd, 86 Deansgate, Manchester, UK
| | - Natalia Lozovaya
- B&A Therapeutics, Ben-Ari Institute of Neuroarcheology, Batiment Beret-Delaage, Zone Luminy Biotech Entreprises, Marseille, Cedex 09, France
| | - Nail Burnashev
- INSERM UMR1249, Mediterranean Institute of Neurobiology (INMED), Aix-Marseille University, Parc Scientifique de Luminy, Marseille, France
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D-serine mitigates cell loss associated with temporal lobe epilepsy. Nat Commun 2020; 11:4966. [PMID: 33009404 PMCID: PMC7532172 DOI: 10.1038/s41467-020-18757-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 09/09/2020] [Indexed: 11/23/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is the most common type of drug-resistant epilepsy in adults, with an unknown etiology. A hallmark of TLE is the characteristic loss of layer 3 neurons in the medial entorhinal area (MEA) that underlies seizure development. One approach to intervention is preventing loss of these neurons through better understanding of underlying pathophysiological mechanisms. Here, we show that both neurons and glia together give rise to the pathology that is mitigated by the amino acid D-serine whose levels are potentially diminished under epileptic conditions. Focal administration of D-serine to the MEA attenuates neuronal loss in this region thereby preventing epileptogenesis in an animal model of TLE. Additionally, treatment with D-serine reduces astrocyte counts in the MEA, alters their reactive status, and attenuates proliferation and/or infiltration of microglia to the region thereby curtailing the deleterious consequences of neuroinflammation. Given the paucity of compounds that reduce hyperexcitability and neuron loss, have anti-inflammatory properties, and are well tolerated by the brain, D-serine, an endogenous amino acid, offers new hope as a therapeutic agent for refractory TLE. Temporal lobe epilepsy (TLE) can be unresponsive to treatment. Here, the authors show that treatment with D-Serine mitigates TLE and acts on neurons and glia, attenuating neuronal loss and reducing astro- and microgliosis in rodents.
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Zheng Y, Zhang K, Dong L, Tian C. Study on the mechanism of high-frequency stimulation inhibiting low-Mg 2+-induced epileptiform discharges in juvenile rat hippocampal slices. Brain Res Bull 2020; 165:1-13. [PMID: 32961285 DOI: 10.1016/j.brainresbull.2020.09.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/02/2020] [Accepted: 09/09/2020] [Indexed: 11/29/2022]
Abstract
Study on the mechanism of high-frequency stimulation inhibiting low-Mg2+-induced epileptiform discharges in juvenile rat hippocampal slices High-frequency stimulation (HFS) has been demonstrated to be an effective treatment for inhibiting epilepsy in some clinical and laboratory studies. However, the mechanisms underlying the therapeutic effects of HFS are not yet fully understood. In our present study, epileptiform discharges (EDs) in acutely isolated hippocampal slices of male Sprague-Dawley (SD) juvenile rats induced by low-Mg2+ artificial cerebrospinal fluid (ACSF), and electrical stimulation (square wave, 900 pulses, 50 % duty-cycle, 130 Hz) was performed on the CA3 using concentric bipolar electrodes. EDs of neurons in hippocampal were recorded by multi-electrode arrays (MEA). After stable EDs events had been recorded for at least 20 min, HFS was added, followed by 10 μmol/L gamma-aminobutyric acid type A (GABAA) receptors blocker bicuculline (BIC). The results show that the HFS can increase the discharges frequency of inter-ictal discharges (IIDs) and decrease the duration of ictal discharges (IDs). However, the HFS had no effect on the slices with 10 μmol/L BIC. These results indicated that the GABAA receptors are activated when HFS inhibited EDs, thereby achieving the inhibition of low-Mg2+-induced EDs in slices.
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Affiliation(s)
- Yu Zheng
- School of Life Sciences, Tiangong University, Tianjin, 300387, China.
| | - Kanghui Zhang
- School of Life Sciences, Tiangong University, Tianjin, 300387, China
| | - Lei Dong
- State Key Laboratory of Precision Measurement Technology and Instruments, Tianjin University, Tianjin, 300072, China
| | - Chunxiao Tian
- School of Life Sciences, Tiangong University, Tianjin, 300387, China
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