1
|
Santos VR, Tilelli CQ, Fernandes A, de Castro OW, Del-Vecchio F, Garcia-Cairasco N. Different types of Status Epilepticus may lead to similar hippocampal epileptogenesis processes. IBRO Neurosci Rep 2023; 15:68-76. [PMID: 37457787 PMCID: PMC10338355 DOI: 10.1016/j.ibneur.2023.06.001] [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: 02/15/2023] [Revised: 06/05/2023] [Accepted: 06/05/2023] [Indexed: 07/18/2023] Open
Abstract
About 1-2% of people worldwide suffer from epilepsy, which is characterized by unpredictable and intermittent seizure occurrence. Despite the fact that the exact origin of temporal lobe epilepsy is frequently unknown, it is frequently linked to an early triggering insult like brain damage, tumors, or Status Epilepticus (SE). We used an experimental approach consisting of electrical stimulation of the amygdaloid complex to induce two behaviorally and structurally distinct SE states: Type I (fully convulsive), with more severe seizure behaviors and more extensive brain damage, and Type II (partial convulsive), with less severe seizure behaviors and brain damage. Our goal was to better understand how the various types of SE impact the hippocampus leading to the development of epilepsy. Despite clear variations between the two behaviors in terms of neurodegeneration, study of neurogenesis revealed a comparable rise in the number of Ki-67 + cells and an increase in Doublecortin (DCX) in both kinds of SE.
Collapse
Affiliation(s)
- Victor R. Santos
- Department of Physiology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
- Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, MG, Brazil
| | - Cristiane Q. Tilelli
- Department of Physiology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
- Campus Centro-Oeste Dona Lindu, Federal University of São João Del Rey, Divinópolis, MG, Brazil
| | - Artur Fernandes
- Department of Physiology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Olagide Wagner de Castro
- Department of Physiology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
- Department of Pharmacology and Physiology, Universidade Federal de Alagoas, Maceió, AL, Brazil
| | - Flávio Del-Vecchio
- Department of Physiology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Norberto Garcia-Cairasco
- Department of Physiology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
| |
Collapse
|
2
|
Negi D, Granak S, Shorter S, O'Leary VB, Rektor I, Ovsepian SV. Molecular Biomarkers of Neuronal Injury in Epilepsy Shared with Neurodegenerative Diseases. Neurotherapeutics 2023; 20:767-778. [PMID: 36884195 PMCID: PMC10275849 DOI: 10.1007/s13311-023-01355-7] [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] [Accepted: 02/08/2023] [Indexed: 03/09/2023] Open
Abstract
In neurodegenerative diseases, changes in neuronal proteins in the cerebrospinal fluid and blood are viewed as potential biomarkers of the primary pathology in the central nervous system (CNS). Recent reports suggest, however, that level of neuronal proteins in fluids also alters in several types of epilepsy in various age groups, including children. With increasing evidence supporting clinical and sub-clinical seizures in Alzheimer's disease, Lewy body dementia, Parkinson's disease, and in other less common neurodegenerative conditions, these findings call into question the specificity of neuronal protein response to neurodegenerative process and urge analysis of the effects of concomitant epilepsy and other comorbidities. In this article, we revisit the evidence for alterations in neuronal proteins in the blood and cerebrospinal fluid associated with epilepsy with and without neurodegenerative diseases. We discuss shared and distinctive characteristics of changes in neuronal markers, review their neurobiological mechanisms, and consider the emerging opportunities and challenges for their future research and diagnostic use.
Collapse
Affiliation(s)
- Deepika Negi
- Faculty of Engineering and Science, University of Greenwich London, Chatham Maritime, Kent, ME4 4TB, UK
| | - Simon Granak
- National Institute of Mental Health, Topolova 748, Klecany, 25067, Czech Republic
| | - Susan Shorter
- Faculty of Engineering and Science, University of Greenwich London, Chatham Maritime, Kent, ME4 4TB, UK
| | - Valerie B O'Leary
- Department of Medical Genetics, Third Faculty of Medicine, Charles University, Ruská 87, Prague, 10000, Czech Republic
| | - Ivan Rektor
- First Department of Neurology, St. Anne's University Hospital and Faculty of Medicine, Masaryk University, Brno, Czech Republic
- Multimodal and Functional Neuroimaging Research Group, CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Saak V Ovsepian
- Faculty of Engineering and Science, University of Greenwich London, Chatham Maritime, Kent, ME4 4TB, UK.
| |
Collapse
|
3
|
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.
Collapse
|
4
|
Suha AJ, Sadr SS, Roghani M, Haftcheshmeh SM, Khamse S, Momtazi-Borojeni AA. Ferulic Acid Attenuates Kainate-induced Neurodegeneration in a Rat Poststatus Epilepticus Model. Curr Mol Pharmacol 2023; 16:178-187. [PMID: 35232370 DOI: 10.2174/1874467215666220225093737] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/30/2021] [Accepted: 12/16/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND AIMS Increasing research evidence indicates that temporal lobe epilepsy (TLE) induced by kainic acid (KA) has high pathological similarities with human TLE. KA induces excitotoxicity (especially in the acute phase of the disease), which leads to neurodegeneration and epileptogenesis through oxidative stress and inflammation. Ferulic acid (FA) is one of the well-known phytochemical compounds that have shown potential antioxidant and anti-inflammatory properties and promise in treating several diseases. The current study set out to investigate the neuroprotective effects of FA in a rat model of TLE. METHODS Thirty-six male Wistar rats were divided into four groups. Pretreatment with FA (100 mg/kg/day p.o.) started one week before the intrahippocampal injection of KA (0.8 μg/μl, 5μl). Seizures were recorded and evaluated according to Racine's scale. Oxidative stress was assessed by measuring its indicators, including malondialdehyde (MDA), nitrite, and catalase. Histopathological evaluations including Nissl staining and immunohistochemical staining of cyclooxygenase-2 (COX-2), and neural nitric oxide synthases (nNOS) were performed for the CA3 region of the hippocampus. RESULTS Pretreatment with FA significantly attenuates the severity of the seizure and prevents neuronal loss in the CA3 region of the hippocampus in rats with KA-induced post-status epilepticus. Also, nitrite concentration and nNOS levels were markedly diminished in FA-pretreated animals compared to non-pretreated epileptic rats. CONCLUSION Our findings indicated that neuroprotective properties of FA, therefore, could be considered a valuable therapeutic supplement in treating TLE.
Collapse
Affiliation(s)
- Ali Jaafari Suha
- Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Electrophysiology Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Shahabeddin Sadr
- Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Electrophysiology Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehrdad Roghani
- Neurophysiology Research Center, Shahed University, Tehran, Iran
| | - Saeed Mohammadian Haftcheshmeh
- Department of Basic Medical Sciences, Neyshabur University of Medical Sciences, Neyshabur, Iran
- Healthy Ageing Research Centre, Neyshabur University of Medical Sciences, Neyshabur, Iran
| | - Safoura Khamse
- Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Electrophysiology Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Amir Abbas Momtazi-Borojeni
- Department of Medical Biotechnology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Iran's National Elites Foundation, Tehran, Iran
| |
Collapse
|
5
|
Kang W, Ju C, Joo J, Lee J, Shon YM, Park SM. Closed-loop direct control of seizure focus in a rodent model of temporal lobe epilepsy via localized electric fields applied sequentially. Nat Commun 2022; 13:7805. [PMID: 36528681 PMCID: PMC9759546 DOI: 10.1038/s41467-022-35540-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
Direct electrical stimulation of the seizure focus can achieve the early termination of epileptic oscillations. However, direct intervention of the hippocampus, the most prevalent seizure focus in temporal lobe epilepsy is thought to be not practicable due to its large size and elongated shape. Here, in a rat model, we report a sequential narrow-field stimulation method for terminating seizures, while focusing stimulus energy at the spatially extensive hippocampal structure. The effects and regional specificity of this method were demonstrated via electrophysiological and biological responses. Our proposed modality demonstrates spatiotemporal preciseness and selectiveness for modulating the pathological target region which may have potential for further investigation as a therapeutic approach.
Collapse
Affiliation(s)
- Wonok Kang
- grid.49100.3c0000 0001 0742 4007School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea
| | - Chanyang Ju
- grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Convergence IT Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea
| | - Jaesoon Joo
- grid.264381.a0000 0001 2181 989XBiomedical Engineering Research Center, Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul, 06351 South Korea
| | - Jiho Lee
- grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Convergence IT Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea
| | - Young-Min Shon
- grid.264381.a0000 0001 2181 989XBiomedical Engineering Research Center, Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul, 06351 South Korea ,grid.264381.a0000 0001 2181 989XDepartment of Neurology, Samsung Medical Center, School of Medicine, Sungkyunkwan University, Seoul, 06351 Republic of Korea
| | - Sung-Min Park
- grid.49100.3c0000 0001 0742 4007School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Medical Device Innovation Center, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Convergence IT Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Electrical Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.49100.3c0000 0001 0742 4007Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673 Republic of Korea ,grid.15444.300000 0004 0470 5454Institute of Convergence Science, Yonsei University, Seoul, 03722 Republic of Korea
| |
Collapse
|
6
|
Dohm-Hansen S, Donoso F, Lucassen PJ, Clarke G, Nolan YM. The gut microbiome and adult hippocampal neurogenesis: A new focal point for epilepsy? Neurobiol Dis 2022; 170:105746. [DOI: 10.1016/j.nbd.2022.105746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 04/13/2022] [Accepted: 04/29/2022] [Indexed: 02/07/2023] Open
|
7
|
de Curtis M, Rossetti AO, Verde DV, van Vliet EA, Ekdahl CT. Brain pathology in focal status epilepticus: evidence from experimental models. Neurosci Biobehav Rev 2021; 131:834-846. [PMID: 34517036 DOI: 10.1016/j.neubiorev.2021.09.011] [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: 04/20/2021] [Revised: 09/02/2021] [Accepted: 09/05/2021] [Indexed: 12/01/2022]
Abstract
Status Epilepticus (SE) is often a neurological emergency characterized by abnormally sustained, longer than habitual seizures. The new ILAE classification reports that SE "…can have long-term consequences including neuronal death, neuronal injury…depending on the type and duration of seizures". While it is accepted that generalized convulsive SE exerts detrimental effects on the brain, it is not clear if other forms of SE, such as focal non-convulsive SE, leads to brain pathology and contributes to long-term deficits in patients. With the available clinical and experimental data, it is hard to discriminate the specific action of the underlying SE etiologies from that exerted by epileptiform activity. This information is highly relevant in the clinic for better treatment stratification, which may include both medical and surgical intervention for seizure control. Here we review experimental studies of focal SE, with an emphasis on focal non-convulsive SE. We present a repertoire of brain pathologies observed in the most commonly used animal models and attempt to establish a link between experimental findings and human condition(s). The extensive literature on focal SE animal models suggest that the current approaches have significant limitations in terms of translatability of the findings to the clinic. We highlight the need for a more stringent description of SE features and brain pathology in experimental studies in animal models, to improve the accuracy in predicting clinical translation.
Collapse
Affiliation(s)
- Marco de Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto NeurologicoCarlo Besta, Milano, Italy.
| | - Andrea O Rossetti
- Department of Clinical Neuroscience, University Hospital (CHUV) and University of Lausanne, Lausanne, Switzerland
| | - Diogo Vila Verde
- Epilepsy Unit, Fondazione IRCCS Istituto NeurologicoCarlo Besta, Milano, Italy
| | - Erwin A van Vliet
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, P.O. Box 94246, 1090 GE, Amsterdam, the Netherlands; Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam, the Netherlands
| | - Christine T Ekdahl
- Division of Clinical Neurophysiology, Lund University, Sweden; Lund Epilepsy Center, Dept Clinical Sciences, Lund University, Sweden
| |
Collapse
|
8
|
Butler-Ryan R, Wood IC. The functions of repressor element 1-silencing transcription factor in models of epileptogenesis and post-ischemia. Metab Brain Dis 2021; 36:1135-1150. [PMID: 33813634 PMCID: PMC8272694 DOI: 10.1007/s11011-021-00719-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/17/2021] [Indexed: 12/14/2022]
Abstract
Epilepsy is a debilitating neurological disorder characterised by recurrent seizures for which 30% of patients are refractory to current treatments. The genetic and molecular aetiologies behind epilepsy are under investigation with the goal of developing new epilepsy medications. The transcriptional repressor REST (Repressor Element 1-Silencing Transcription factor) is a focus of interest as it is consistently upregulated in epilepsy patients and following brain insult in animal models of epilepsy and ischemia. This review analyses data from different epilepsy models and discusses the contribution of REST to epileptogenesis. We propose that in healthy brains REST acts in a protective manner to homeostatically downregulate increases in excitability, to protect against seizure through downregulation of BDNF (Brain-Derived Neurotrophic Factor) and its receptor, TrkB (Tropomyosin receptor kinase B). However, in epilepsy patients and post-seizure, REST may increase to a larger degree, which allows downregulation of the glutamate receptor subunit GluR2. This leads to AMPA glutamate receptors lacking GluR2 subunits, which have increased permeability to Ca2+, causing excitotoxicity, cell death and seizure. This concept highlights therapeutic potential of REST modulation through gene therapy in epilepsy patients.
Collapse
Affiliation(s)
- Ruth Butler-Ryan
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, LS2 9JT UK
| | - Ian C. Wood
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, LS2 9JT UK
| |
Collapse
|
9
|
Bertoglio D, Amhaoul H, Goossens J, Ali I, Jonckers E, Bijnens T, Siano M, Wyffels L, Verhaeghe J, Van der Linden A, Staelens S, Dedeurwaerdere S. TSPO PET upregulation predicts epileptic phenotype at disease onset independently from chronic TSPO expression in a rat model of temporal lobe epilepsy. Neuroimage Clin 2021; 31:102701. [PMID: 34090124 PMCID: PMC8182303 DOI: 10.1016/j.nicl.2021.102701] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/10/2021] [Accepted: 05/14/2021] [Indexed: 12/12/2022]
Abstract
Neuroinflammation is a key component of epileptogenesis, the process leading to acquired epilepsy. In recent years, with the development of non-invasive in vivo positron emission tomography (PET) imaging of translocator protein 18 kDa (TSPO), a marker of neuroinflammation, it has become possible to perform longitudinal studies to characterize neuroinflammation at different disease stages in animal models of epileptogenesis. This study aimed to utilize the prognostic capability of TSPO PET imaging at disease onset (2 weeks post-SE) to categorize epileptic rats with distinct seizure burden based on TSPO levels at disease onset and investigate their association to TSPO expression at the chronic epilepsy stage. Controls (n = 14) and kainic acid-induced status epilepticus (KASE) rats (n = 41) were scanned non-invasively with [18F]PBR111 PET imaging measuring TSPO expression. Animals were monitored using video-electroencephalography (vEEG) up to chronic disease (12 weeks post-SE), at which TSPO levels ([3H]PK11195) as well as other post-mortem abnormalities (namely synaptic density ([3H]UCB-J), neuronal loss (NeuN), and neurodegeneration (FjC)) were investigated. By applying multivariate analysis, TSPO PET imaging at disease onset identified three KASE groups with significantly different spontaneous recurrent seizures (SRS) burden (defined as rare SRS, sporadic SRS, and frequent SRS) (p = 0.003). Interestingly, TSPO levels were significantly different when comparing the three KASE groups (p < 0.0001), with the frequent SRS group characterized only by a limited focal TSPO increase at disease onset. On the contrary, TSPO measured during chronic epilepsy was found to be the highest in the frequent SRS group and correlated with seizure burden (r = 0.826, p < 0.0001). Importantly, early and chronic TSPO levels did not correlate (r = -0.05). Finally, significant pathological changes in neuronal loss, synaptic density, and neurodegeneration were found not only when compared to control animals (p < 0.01), but also between the three KASE rat categories in the hippocampus (p < 0.05). Early and chronic TSPO upregulation following epileptogenic insult appear to be driven by two superimposed dynamic processes. The former is associated with epileptogenesis as measured at disease onset, while the latter is related to seizure frequency as quantified during chronic epilepsy.
Collapse
Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium; Department of Translational Neurosciences, University of Antwerp, Belgium.
| | - Halima Amhaoul
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | - Joery Goossens
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | - Idrish Ali
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | | | - Tom Bijnens
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | - Matteo Siano
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | - Leonie Wyffels
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium; Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium
| | | | - Steven Staelens
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | | |
Collapse
|
10
|
Suleymanova EM. Behavioral comorbidities of epilepsy and neuroinflammation: Evidence from experimental and clinical studies. Epilepsy Behav 2021; 117:107869. [PMID: 33684786 DOI: 10.1016/j.yebeh.2021.107869] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/14/2021] [Accepted: 02/14/2021] [Indexed: 12/24/2022]
Abstract
Currently, a significant amount of data is accumulated showing that neuroinflammation is one of the key processes in the development of brain pathology in trauma, neurodegenerative diseases, and epilepsy. Various brain insults, such as prolonged seizure activity, trigger the activation of microglia and astrocytes in the brain. These cells, in turn, begin to synthesize pro-inflammatory cytokines. The inflammatory response to the insult causes a cascade of processes leading to a wide range of pathological effects, including changes in neuronal excitability, long-term plastic changes, astrocyte dysfunction, impaired blood-brain barrier (BBB) permeability, and neurodegeneration. These effects may ultimately contribute to the development of chronic spontaneous seizures. On the other hand, neuroinflammation contributes to the pathogenesis of a number of neuropsychiatric disorders. Therefore, neuroinflammation can be a link between epilepsy and its comorbidities, such as mood and anxiety disorders and memory impairment. The mechanisms behind these behavioral and cognitive impairments remain not fully understood. In this paper, clinical evidence of an important role of neuroinflammation in epilepsy and potentially comorbid neurological disorders is reviewed, as well as possible mechanisms of its involvement in the pathogenesis of these conditions obtained from experimental data.
Collapse
Affiliation(s)
- Elena M Suleymanova
- Institute of Higher Nervous Activity and Neurophysiology of RAS, 117485 Butlerova 5A, Moscow, Russia.
| |
Collapse
|
11
|
Mathern GW, Bertram EH. Recurrent limbic seizures do not cause hippocampal neuronal loss: A prolonged laboratory study. Neurobiol Dis 2020; 148:105183. [PMID: 33207277 PMCID: PMC7855788 DOI: 10.1016/j.nbd.2020.105183] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 11/02/2022] Open
Abstract
PURPOSE It remains controversial whether neuronal damage and synaptic reorganization found in some forms of epilepsy are the result of an initial injury and potentially contributory to the epileptic condition or are the cumulative affect of repeated seizures. A number of reports of human and animal pathology suggest that at least some neuronal loss precedes the onset of seizures, but there is debate over whether there is further damage over time from intermittent seizures. In support of this latter hypothesis are MRI studies in people that show reduced hippocampal volumes and cortical thickness with longer durations of the disease. In this study we addressed the question of neuronal loss from intermittent seizures using kindled rats (no initial injury) and rats with limbic epilepsy (initial injury). METHODS Supragranular mossy fiber sprouting, hippocampal neuronal densities, and subfield area measurements were determined in rats with chronic limbic epilepsy (CLE) that developed following an episode of limbic status epilepticus (n = 25), in kindled rats (n = 15), and in age matched controls (n = 20). To determine whether age or seizure frequency played a role in the changes, CLE and kindled rats were further classified by seizure frequency (low/high) and the duration of the seizure disorder (young/old). RESULTS Overall there was no evidence for progressive neuronal loss from recurrent seizures. Compared with control and kindled rats, CLE animals showed increased mossy fiber sprouting, decreased neuronal numbers in multiple regions and regional atrophy. In CLE, but not kindled rats: 1) Higher seizure frequency was associated with greater mossy fiber sprouting and granule cell dispersion; and 2) greater age with seizures was associated with decreased hilar densities, and increased hilar areas. There was no evidence for progressive neuronal loss, even with more than 1000 seizures. CONCLUSION These findings suggest that the neuronal loss associated with limbic epilepsy precedes the onset of the seizures and is not a consequence of recurrent seizures. However, intermittent seizures do cause other structural changes in the brain, the functional consequences of which are unclear.
Collapse
Affiliation(s)
- Gary W Mathern
- Division of Neurosurgery, The Mental Retardation Research Center, United States of America; Division of Neurosurgery, The Brain Research Institute, United States of America; University of California, Los Angeles, Los Angeles, California, United States of America
| | - Edward H Bertram
- Department of Neurology, University of Virginia, Charlottesville, Virginia, United States of America.
| |
Collapse
|
12
|
Insights into Potential Targets for Therapeutic Intervention in Epilepsy. Int J Mol Sci 2020; 21:ijms21228573. [PMID: 33202963 PMCID: PMC7697405 DOI: 10.3390/ijms21228573] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/04/2020] [Accepted: 11/11/2020] [Indexed: 02/06/2023] Open
Abstract
Epilepsy is a chronic brain disease that affects approximately 65 million people worldwide. However, despite the continuous development of antiepileptic drugs, over 30% patients with epilepsy progress to drug-resistant epilepsy. For this reason, it is a high priority objective in preclinical research to find novel therapeutic targets and to develop effective drugs that prevent or reverse the molecular mechanisms underlying epilepsy progression. Among these potential therapeutic targets, we highlight currently available information involving signaling pathways (Wnt/β-catenin, Mammalian Target of Rapamycin (mTOR) signaling and zinc signaling), enzymes (carbonic anhydrase), proteins (erythropoietin, copine 6 and complement system), channels (Transient Receptor Potential Vanilloid Type 1 (TRPV1) channel) and receptors (galanin and melatonin receptors). All of them have demonstrated a certain degree of efficacy not only in controlling seizures but also in displaying neuroprotective activity and in modifying the progression of epilepsy. Although some research with these specific targets has been done in relation with epilepsy, they have not been fully explored as potential therapeutic targets that could help address the unsolved issue of drug-resistant epilepsy and develop new antiseizure therapies for the treatment of epilepsy.
Collapse
|
13
|
Wu X, Zhou Y, Huang Z, Cai M, Shu Y, Zeng C, Feng L, Xiao B, Zhan Q. The study of microtubule dynamics and stability at the postsynaptic density in a rat pilocarpine model of temporal lobe epilepsy. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:863. [PMID: 32793707 DOI: 10.21037/atm-19-4636] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background The recurrence and drug resistance of temporal lobe epilepsy (TLE) has been ceaselessly challenging scientists and epilepsy experts. There has been an accumulation of evidence linking the dysregulation of postsynaptic proteins etiology and the pathology of epilepsy. For example, NMDA receptors, AMPA receptors, and metabotropic glutamate receptors (mGluRs). Furthermore, our earlier proteomic analysis proved there to be differential expressions of cytoskeletons like microtubules among rat groups. These differential expressions were shown in TLE-spontaneous recurrent seizures (TLE-SRS), TLE without SRS (TLE-NSRS) and control groups. Therefore, we aimed to understand how the microtubule system of the hippocampal postsynaptic density (PSD) regulates the development of TLE. Methods In this study, a pilocarpine-induced Sprague-Dawley rat TLE model were used, and Western blot, Nissl staining, and the immunoelectron microscopic method were utilized to determine the dynamic change of microtubules (α- and β-tubulin) in PSD and the extent of hippocampal neuron loss respectively in acute SE, and latent and chronic (spontaneous seizures) periods. Animal models were then stereotactically treated using colchicine, a microtubule depolymerizer, and paclitaxel, a microtubule polymerization agent, after each animal's acute SE period so as to further explore the function of PSD microtubules. Results Our study revealed 3 principal findings. One, both α- and β-tubulin were decreased from the 3rd to the 30th day (lowest at the 7th day) in the seizure group compared with the controls. Two, both α- and β-tubulin were found to be more downregulated in the TLE-SRS and the TLE-NSRS group than in the control group (especially in the TLE-SRS group). The same trend was also noticed for hippocampal neuron loss. Three, the paclitaxel lowered the chronic SRS rate and increased the expression of PSD β-tubulin in the hippocampus. Conclusions Altogether, these results indicate that the microtubule system of PSD may play an essential role in the development and recurrence of epilepsy, and it may be used as a new target for the prevention and treatment of this refractory disease.
Collapse
Affiliation(s)
- Xiaomei Wu
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Ying Zhou
- Department of Neurology, The First Hospital of Changsha, Changsha, China
| | - Zhiling Huang
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Mingfei Cai
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Yi Shu
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Chang Zeng
- Health Management Center, Xiangya Hospital, Central South University, Changsha, China
| | - Li Feng
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Qiong Zhan
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| |
Collapse
|
14
|
Lucassen PJ, Fitzsimons CP, Salta E, Maletic-Savatic M. Adult neurogenesis, human after all (again): Classic, optimized, and future approaches. Behav Brain Res 2020; 381:112458. [DOI: 10.1016/j.bbr.2019.112458] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 11/29/2019] [Accepted: 12/28/2019] [Indexed: 02/08/2023]
|
15
|
Swissa E, Serlin Y, Vazana U, Prager O, Friedman A. Blood-brain barrier dysfunction in status epileptics: Mechanisms and role in epileptogenesis. Epilepsy Behav 2019; 101:106285. [PMID: 31711869 DOI: 10.1016/j.yebeh.2019.04.038] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 04/19/2019] [Indexed: 12/12/2022]
Abstract
The blood-brain barrier (BBB), a unique anatomical and physiological interface between the central nervous system (CNS) and the peripheral circulation, is essential for the function of neural circuits. Interactions between the BBB, cerebral blood vessels, neurons, astrocytes, microglia, and pericytes form a dynamic functional unit known as the neurovascular unit (NVU). The NVU-BBB crosstalk plays a key role in the regulation of blood flow, response to injury, neuronal firing, and synaptic plasticity. Blood-brain barrier dysfunction (BBBD), a hallmark of brain injury, is a prominent finding in status epilepticus. Blood-brain barrier dysfunction is observed within the first hour of status epilepticus, and in epileptogenic brain regions, may last for months. Blood-brain barrier dysfunction was shown to have a role in astroglial dysfunction, neuroinflammation, increasing neural excitability, reduction of seizure threshold, excitatory synaptogenesis, impaired plasticity, and epileptogenesis. A key signaling pathway associated with BBBD-induced neurovascular dysfunction is the transforming growth factor beta (TGF-β) proinflammatory pathway, activated by the extravasation of serum albumin into the brain when BBB functions are compromised. Specific small molecules blocking TGF-β, and the nonspecific, Food and Drug Administration (FDA) approved blocker and angiotensin antagonist losartan, were shown to reduce BBBD and block epileptogenesis. With these encouraging preclinical data, we have developed imaging approach to quantitatively assess BBBD as a diagnostic, predictive, and pharmacodynamic biomarker after brain injury. Clinical trials in the foreseen future are expected to test the feasibility of BBB-targeted diagnostic coupled therapy in status epileptics and seizure disorders. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".
Collapse
Affiliation(s)
- Evyatar Swissa
- Departments of Physiology and Cell Biology, Brain and Cognitive Sciences, The Inter-Faculty Brain Science School, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva Israel
| | - Yonatan Serlin
- Neurology Residency Training Program, McGill University, Montreal, QC, Canada
| | - Udi Vazana
- Departments of Physiology and Cell Biology, Brain and Cognitive Sciences, The Inter-Faculty Brain Science School, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva Israel
| | - Ofer Prager
- Departments of Physiology and Cell Biology, Brain and Cognitive Sciences, The Inter-Faculty Brain Science School, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva Israel
| | - Alon Friedman
- Departments of Physiology and Cell Biology, Brain and Cognitive Sciences, The Inter-Faculty Brain Science School, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva Israel; Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada.
| |
Collapse
|
16
|
Chmielewska N, Maciejak P, Turzyńska D, Sobolewska A, Wisłowska-Stanek A, Kołosowska K, Płaźnik A, Szyndler J. The role of UCH-L1, MMP-9, and GFAP as peripheral markers of different susceptibility to seizure development in a preclinical model of epilepsy. J Neuroimmunol 2019; 332:57-63. [PMID: 30952062 DOI: 10.1016/j.jneuroim.2019.03.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 03/06/2019] [Accepted: 03/28/2019] [Indexed: 01/03/2023]
Abstract
In our study, we assessed the potency of the brain-derived proteins ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), matrix metalloproteinase 9 (MMP-9), glial fibrillary acidic protein (GFAP) and the immune activation indicators interleukin 1β (IL-1β) and interleukin 6 (IL-6) as peripheral biomarkers of different susceptibilities to kindling in a preclinical model. We observed increased plasma UCH-L1 levels in kindled vs. control animals. Furthermore, MMP-9 and IL-1β concentrations were the lowest in rats resistant to kindling. In summary, UCH-L1 is an indicator of neuronal loss and BBB disruption after seizure. MMP-9 and IL-1β may indicate resistance to kindling. UCH-L1, MMP-9 and IL-1β may have utility as peripheral biomarkers with translational potency in the clinic.
Collapse
Affiliation(s)
- Natalia Chmielewska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, Sobieskiego Street 9, 02-957 Warsaw, Poland.
| | - Piotr Maciejak
- Department of Neurochemistry, Institute of Psychiatry and Neurology, Sobieskiego Street 9, 02-957 Warsaw, Poland; Department of Experimental and Clinical Pharmacology, Centre for Preclinical Research and Technology CePT, Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland
| | - Danuta Turzyńska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, Sobieskiego Street 9, 02-957 Warsaw, Poland
| | - Alicja Sobolewska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, Sobieskiego Street 9, 02-957 Warsaw, Poland
| | - Aleksandra Wisłowska-Stanek
- Department of Experimental and Clinical Pharmacology, Centre for Preclinical Research and Technology CePT, Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland
| | - Karolina Kołosowska
- Department of Neurochemistry, Institute of Psychiatry and Neurology, Sobieskiego Street 9, 02-957 Warsaw, Poland
| | - Adam Płaźnik
- Department of Neurochemistry, Institute of Psychiatry and Neurology, Sobieskiego Street 9, 02-957 Warsaw, Poland; Department of Experimental and Clinical Pharmacology, Centre for Preclinical Research and Technology CePT, Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland
| | - Janusz Szyndler
- Department of Experimental and Clinical Pharmacology, Centre for Preclinical Research and Technology CePT, Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland
| |
Collapse
|
17
|
Noè F, Cattalini A, Vila Verde D, Alessi C, Colciaghi F, Figini M, Zucca I, de Curtis M. Epileptiform activity contralateral to unilateral hippocampal sclerosis does not cause the expression of brain damage markers. Epilepsia 2019; 60:1184-1199. [PMID: 31111475 DOI: 10.1111/epi.15611] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/24/2019] [Accepted: 04/24/2019] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Patients with epilepsy often ask if recurrent seizures harm their brain and aggravate their epileptic condition. This crucial question has not been specifically addressed by dedicated experiments. We analyze here if intense bilateral seizure activity induced by local injection of kainic acid (KA) in the right hippocampus produces brain damage in the left hippocampus. METHODS Adult guinea pigs were bilaterally implanted with hippocampal electrodes for continuous video-electroencephalography (EEG) monitoring. Unilateral injection of 1 μg KA in the dorsal CA1 area induced nonconvulsive status epilepticus (ncSE) characterized by bilateral hippocampal seizure discharges. This treatment resulted in selective unilateral sclerosis of the KA-injected hippocampus. Three days after KA injection, the animals were killed, and the brains were submitted to ex vivo magnetic resonance imaging (MRI) and were processed for immunohistochemical analysis. RESULTS During ncSE, epileptiform activity was recorded for 27.6 ± 19.1 hours in both the KA-injected and contralateral hippocampi. Enhanced T1-weighted MR signal due to gadolinium deposition, mean diffusivity reduction, neuronal loss, gliosis, and blood-brain barrier permeability changes was observed exclusively in the KA-injected hippocampus. Despite the presence of a clear unilateral hippocampal sclerosis at the site of KA injection, no structural alterations were detected by MR and immunostaining analysis performed in the hippocampus contralateral to KA injection 3 days and 2 months after ncSE induction. Fluoro-Jade and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining at the same time points confirmed the absence of degenerating cells in the hippocampi contralateral to KA injection. SIGNIFICANCE We demonstrate that intense epileptiform activity during ncSE does not cause obvious brain damage in the hippocampus contralateral to unilateral hippocampal KA injection. These findings argue against the hypothesis that epileptiform activity per se contributes to focal brain injury in previously undamaged cortical regions.
Collapse
Affiliation(s)
- Francesco Noè
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | | | - Diogo Vila Verde
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Camilla Alessi
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Francesca Colciaghi
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Matteo Figini
- Scientific Direction, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Ileana Zucca
- Scientific Direction, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Marco de Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| |
Collapse
|
18
|
Faghir-Ghanesefat H, Keshavarz-Bahaghighat H, Rajai N, Mokhtari T, Bahramnejad E, Kazemi Roodsari S, Dehpour AR. The Possible Role of Nitric Oxide Pathway in Pentylenetetrazole Preconditioning Against Seizure in Mice. J Mol Neurosci 2019; 67:477-483. [PMID: 30627955 DOI: 10.1007/s12031-018-1256-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 12/28/2018] [Indexed: 11/24/2022]
Abstract
Preconditioning is defined as an induction of adaptive response in organs against lethal stimulation provoked by subsequent mild sublethal stress. Several chemical agents have been demonstrated to cause brain tolerance through preconditioning. The aim of the present study is to test the hypothesis that preconditioning with pentylenetetrazole (PTZ) may have protective effect against seizure induced by i.v. infusion of PTZ. Mice were preconditioned by low-dose administration of PTZ (25 mg/kg) for 5 consecutive days, and the threshold of seizure elicited by i.v. infusion of PTZ was measured. To investigate the possible role of nitric oxide, NOS inhibitor enzymes, including L-NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) (10 mg/kg), aminoguanidine (AG) (50 mg/kg), 7-nitroindazole (7-NI) (15 mg/kg), and L-arginine (L-arg) (60 mg/kg), were administered concomitantly with PTZ in both acute and chronic phases. Determination of seizure threshold revealed significant enhancement after preconditioning with low dose of PTZ. While the protective effect of PTZ preconditioning was enhanced after the administration of L-arg, it was reversed following administration of L-NAME and 7NI, suggesting the involvement of nitric oxide pathway as an underlying mechanism of PTZ-induced preconditioning. Preconditioning with PTZ led to brain tolerance and adaptive response in animal model of PTZ-induced seizure. This effect is in part due to the involvement of nitric oxide pathway.
Collapse
Affiliation(s)
- Hedyeh Faghir-Ghanesefat
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.,Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Hedieh Keshavarz-Bahaghighat
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.,Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Nazanin Rajai
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.,Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Tahmineh Mokhtari
- Nervous System Stem Cells Research Center, Semnan University of Medical Sciences, Semnan, Iran.,Department of Anatomy, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Erfan Bahramnejad
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.,Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Soheil Kazemi Roodsari
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.,Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Dehpour
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran. .,Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
19
|
Mamalyga ML, Mamalyga LM. [The effect of status epilepticus on autonomic regulation of the heart and its functional capabilities in different postictal periods]. Zh Nevrol Psikhiatr Im S S Korsakova 2019; 119:48-54. [PMID: 32207731 DOI: 10.17116/jnevro201911911248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
AIM To study the postictal changes in the autonomic regulation of the heart rhythm and its functional capabilities in different periods after epistatus and to assess the risk of life-threatening arrhythmias. MATERIAL AND METHODS The study was conducted on Wistar rats after epileptic status (ES). Telemonitoring of EEG and ECG was performed in the online mode using the system of the company 'ADInstruments'. Functional stress test with dobutamine was used. RESULTS ES leads to a long-lasting disturbance of autonomic regulation (AR) of the heart and reduces its functional capabilities. The heart's AR balance is shifted towards sympathetic tonus 5 days after ES. This increases the predictors of life-threatening arrhythmias. The decrease in SWD activity increases the activity of parasympathetic tonus 10 days after ES. However, this is due to the tension of regulation mechanisms and the risk of life-threatening arrhythmias. CONCLUSION The high degree of seizure activity of the brain in the ES predetermines prolonged postictal disorders of the AR heart, which reduce its functional capabilities and increase the risk of life-threatening arrhythmias.
Collapse
Affiliation(s)
- M L Mamalyga
- Bakulev National Medical Research Center of Cardiovascular Surgery, Moscow, Russia
| | - L M Mamalyga
- Institute of biology and chemistry of Moscow Pedagogical State University, Moscow, Russia
| |
Collapse
|
20
|
|
21
|
Bertoglio D, Amhaoul H, Van Eetveldt A, Houbrechts R, Van De Vijver S, Ali I, Dedeurwaerdere S. Kainic Acid-Induced Post-Status Epilepticus Models of Temporal Lobe Epilepsy with Diverging Seizure Phenotype and Neuropathology. Front Neurol 2017; 8:588. [PMID: 29163349 PMCID: PMC5681498 DOI: 10.3389/fneur.2017.00588] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 10/20/2017] [Indexed: 12/28/2022] Open
Abstract
The aim of epilepsy models is to investigate disease ontogenesis and therapeutic interventions in a consistent and prospective manner. The kainic acid-induced status epilepticus (KASE) rat model is a widely used, well-validated model for temporal lobe epilepsy (TLE). As we noted significant variability within the model between labs potentially related to the rat strain used, we aimed to describe two variants of this model with diverging seizure phenotype and neuropathology. In addition, we evaluated two different protocols to induce status epilepticus (SE). Wistar Han (Charles River, France) and Sprague-Dawley (Harlan, The Netherlands) rats were subjected to KASE using the Hellier kainic acid (KA) and a modified injection scheme. Duration of SE and latent phase were characterized by video-electroencephalography (vEEG) in a subgroup of animals, while animals were sacrificed 1 week (subacute phase) and 12 weeks (chronic phase) post-SE. In the 12 weeks post-SE groups, seizures were monitored with vEEG. Neuronal loss (neuronal nuclei), microglial activation (OX-42 and translocator protein), and neurodegeneration (Fluorojade C) were assessed. First, the Hellier protocol caused very high mortality in WH/CR rats compared to SD/H animals. The modified protocol resulted in a similar SE severity for WH/CR and SD/H rats, but effectively improved survival rates. The latent phase was significantly shorter (p < 0.0001) in SD/H (median 8.3 days) animals compared to WH/CR (median 15.4 days). During the chronic phase, SD/H rats had more seizures/day compared to WH/CR animals (p < 0.01). However, neuronal degeneration and cell loss were overall more extensive in WH/CR than in SD/H rats; microglia activation was similar between the two strains 1 week post-SE, but higher in WH/CR rats 12 weeks post-SE. These neuropathological differences may be more related to the distinct neurotoxic effects of KA in the two rat strains than being the outcome of seizure burden itself. The divergences in disease progression and seizure outcome, in addition to the histopathological dissimilarities, further substantiate the existence of strain differences for the KASE rat model of TLE.
Collapse
Affiliation(s)
- Daniele Bertoglio
- Department of Translational Neurosciences, University of Antwerp, Antwerp, Belgium
| | - Halima Amhaoul
- Department of Translational Neurosciences, University of Antwerp, Antwerp, Belgium
| | - Annemie Van Eetveldt
- Department of Translational Neurosciences, University of Antwerp, Antwerp, Belgium
| | - Ruben Houbrechts
- Department of Translational Neurosciences, University of Antwerp, Antwerp, Belgium
| | | | - Idrish Ali
- Department of Translational Neurosciences, University of Antwerp, Antwerp, Belgium
| | | |
Collapse
|
22
|
Serotonin depletion increases seizure susceptibility and worsens neuropathological outcomes in kainate model of epilepsy. Brain Res Bull 2017; 134:109-120. [PMID: 28716398 DOI: 10.1016/j.brainresbull.2017.07.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 07/07/2017] [Accepted: 07/10/2017] [Indexed: 11/22/2022]
Abstract
Serotonin is implicated in the regulation of seizures, but whether or not it can potentiate the effects of epileptogenic factors is not fully established. Using the kainic acid model of epilepsy in rats, we tested the effects of serotonin depletion on (1) susceptibility to acute seizures, (2) development of spontaneous recurrent seizures and (3) behavioral and neuroanatomical sequelae of kainic acid treatment. Serotonin was depleted by pretreating rats with p-chlorophenylalanine. In different groups, kainic acid was injected at 3 different doses: 6.5mg/kg, 9.0mg/kg or 12.5mg/kg. A single dose of 6.5mg/kg of kainic acid reliably induced status epilepticus in p-chlorophenylalanine-pretreated rats, but not in saline-pretreated rats. The neuroexcitatory effects of kainic acid in the p-chlorophenylalanine-pretreated rats, but not in saline-pretreated rats, were associated with the presence of tonic-clonic convulsions and high lethality. Compared to controls, a greater portion of serotonin-depleted rats showed spontaneous recurrent seizures after kainic acid injections. Loss of hippocampal neurons and spatial memory deficits associated with kainic acid treatment were exacerbated by prior depletion of serotonin. The present findings are of particular importance because they suggest that low serotonin activity may represent one of the major risk factors for epilepsy and, thus, offer potentially relevant targets for prevention of epileptogenesis.
Collapse
|
23
|
Broekaart DWM, van Scheppingen J, Geijtenbeek KW, Zuidberg MRJ, Anink JJ, Baayen JC, Mühlebner A, Aronica E, Gorter JA, van Vliet EA. Increased expression of (immuno)proteasome subunits during epileptogenesis is attenuated by inhibition of the mammalian target of rapamycin pathway. Epilepsia 2017. [DOI: 10.1111/epi.13823] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Diede W. M. Broekaart
- Department of (Neuro)Pathology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
| | - Jackelien van Scheppingen
- Department of (Neuro)Pathology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
| | - Karlijne W. Geijtenbeek
- Department of (Neuro)Pathology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
| | - Mark R. J. Zuidberg
- Department of (Neuro)Pathology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
| | - Jasper J. Anink
- Department of (Neuro)Pathology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
| | - Johannes C. Baayen
- Department of Neurosurgery; VU University Medical Center; Vrije Universiteit; Amsterdam The Netherlands
| | - Angelika Mühlebner
- Department of (Neuro)Pathology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
- Swammerdam Institute for Life Sciences; Center for Neuroscience; University of Amsterdam; Amsterdam The Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN); Heemstede The Netherlands
| | - Jan A. Gorter
- Swammerdam Institute for Life Sciences; Center for Neuroscience; University of Amsterdam; Amsterdam The Netherlands
| | - Erwin A. van Vliet
- Department of (Neuro)Pathology; Academic Medical Center; University of Amsterdam; Amsterdam The Netherlands
| |
Collapse
|
24
|
Wu T, Ido K, Osada Y, Kotani S, Tamaoka A, Hanada T. The neuroprotective effect of perampanel in lithium-pilocarpine rat seizure model. Epilepsy Res 2017. [PMID: 28624183 DOI: 10.1016/j.eplepsyres.2017.06.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE Status epilepticus (SE) causes irreversible neurodegeneration if not terminated quickly. Perampanel (PER), a potent AMPA receptor antagonist, has previously been shown to terminate seizures in the lithium-pilocarpine SE model. In the present study, we assessed whether PER would also prevent neuronal damage in this model. METHODS SE was induced in rats using lithium chloride and pilocarpine. Initiation of SE was defined as continuous seizures that exhibited as rearing accompanied by bilateral forelimb clonus (Racine score 4). Either PER (0.6, 2, or 6mg/kg) or diazepam (DZP, 10mg/kg) was administered intravenously 30min after SE initiation. Histopathological samples from treated and seizure-naive rats were taken one week after treatment and then stained with an anti-neuronal nuclei (NeuN) antibody. The sections were analyzed by using a pixel-counting algorithm to quantify the amount of staining in the CA1 subregion of the hippocampus, piriform cortex (Pir), and mediodorsal thalamic nucleus (MD). RESULTS DZP administration did not suppress seizures or the degeneration of neurons in the examined areas. Seizures were terminated in 100% of rats treated with 6mg/kg PER (n=8) and in 47% (7/15) of rats treated with 2mg/kg PER, and neurons in the analyzed areas of these animals were preserved to the level seen in naive rats. In the eight animals in which 2mg/kg PER did not terminate the seizures, neuronal loss was partially attenuated in CA1 and Pir, and neurons were fully preserved in MD. Treatment with 0.6mg/kg PER did not terminate the seizures or significantly preserve neurons. The anti-seizure effect of PER correlated well with the degree of neuroprotection in each analyzed area. CONCLUSIONS PER exhibited a strong neuroprotective effect in a drug-refractory SE model, and this effect was correlated with its attenuation of seizure.
Collapse
Affiliation(s)
- Ting Wu
- Neurology, Tsukuba Research Department, Discovery, Medicine Creation, Neurology Business Group, Eisai Co., Ltd., Japan; Clinical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan.
| | - Katsutoshi Ido
- Neurology, Tsukuba Research Department, Discovery, Medicine Creation, Neurology Business Group, Eisai Co., Ltd., Japan
| | - Yoshihide Osada
- Neurology, Tsukuba Research Department, Discovery, Medicine Creation, Neurology Business Group, Eisai Co., Ltd., Japan
| | - Sadaharu Kotani
- Neurology, Tsukuba Research Department, Discovery, Medicine Creation, Neurology Business Group, Eisai Co., Ltd., Japan
| | - Akira Tamaoka
- Institute of Clinical Medicine, Department of Neurology, University of Tsukuba, Japan
| | - Takahisa Hanada
- Neurology, Tsukuba Research Department, Discovery, Medicine Creation, Neurology Business Group, Eisai Co., Ltd., Japan
| |
Collapse
|
25
|
Khalil A, Kovac S, Morris G, Walker MC. Carvacrol after status epilepticus (SE) prevents recurrent SE, early seizures, cell death, and cognitive decline. Epilepsia 2017; 58:263-273. [DOI: 10.1111/epi.13645] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/15/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Aytakin Khalil
- UCL Institute of Neurology; University College London; London United Kingdom
| | - Stjepana Kovac
- UCL Institute of Neurology; University College London; London United Kingdom
- Department of Neurology; University of Münster; Münster Germany
| | - Gareth Morris
- UCL Institute of Neurology; University College London; London United Kingdom
| | - Matthew C. Walker
- UCL Institute of Neurology; University College London; London United Kingdom
| |
Collapse
|
26
|
Abstract
Development of spontaneous seizures is the hallmark of human epilepsy. There is a critical need for new epilepsy models in order to elucidate mechanisms responsible for leading to the development of spontaneous seizures and for testing new anti-epileptic compounds. Moreover, rodent models of epilepsy have clearly demonstrated that there are two independent seizure systems in the brain: 1) the forebrain seizure network required for the expression of clonic seizures mediated by forebrain neurocircuitry, and 2) the brainstem seizure network necessary for the expression of brainstem or tonic seizures mediated by brainstem neurocircuitry. In seizure naïve animals, these two systems are separate, but developing models that can explore the intersection of the forebrain and brainstem seizure systems or for elucidating mechanisms responsible for bringing these two seizure systems together may aid in our understanding of: 1) how seizures can become more complex overtime, and 2) sudden unexpected death in epilepsy (SUDEP) since propagation of seizure discharge from the forebrain seizure system to the brainstem seizure system may have an important role in SUDEP because many cardiorespiratory systems are localized in the brainstem. The repeated flurothyl seizure model of epileptogenesis, as described here, may aid in providing insight into these important epilepsy issues in addition to understanding how spontaneous seizures develop.
Collapse
Affiliation(s)
- Russell J Ferland
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA.,Department of Neurology, Albany Medical College, Albany, NY 12208, USA
| |
Collapse
|
27
|
Schipper S, Aalbers MW, Rijkers K, Lagiere M, Bogaarts JG, Blokland A, Klinkenberg S, Hoogland G, Vles JSH. Accelerated cognitive decline in a rodent model for temporal lobe epilepsy. Epilepsy Behav 2016; 65:33-41. [PMID: 27865173 DOI: 10.1016/j.yebeh.2016.08.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/20/2016] [Accepted: 08/25/2016] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Cognitive impairment is frequently observed in patients with temporal lobe epilepsy. It is hypothesized that cumulative seizure exposure causes accelerated cognitive decline in patients with epilepsy. We investigated the influence of seizure frequency on cognitive decline in a rodent model for temporal lobe epilepsy. METHODS Neurobehavioral assessment was performed before and after surgery, after the induction of self-sustaining limbic status epilepticus (SSLSE), and in the chronic phase in which rats experienced recurrent seizures. Furthermore, we assessed potential confounders of memory performance. RESULTS Rats showed a deficit in spatial working memory after the induction of the SSLSE, which endured in the chronic phase. A progressive decline in recognition memory developed in SSLSE rats. Confounding factors were absent. Seizure frequency and also the severity of the status epilepticus were not correlated with the severity of cognitive deficits. SIGNIFICANCE The effect of the seizure frequency on cognitive comorbidity in epilepsy has long been debated, possibly because of confounders such as antiepileptic medication and the heterogeneity of epileptic etiologies. In an animal model of temporal lobe epilepsy, we showed that a decrease in spatial working memory does not relate to the seizure frequency. This suggests for other mechanisms are responsible for memory decline and potentially a common pathophysiology of cognitive deterioration and the occurrence and development of epileptic seizures. Identifying this common denominator will allow development of more targeted interventions treating cognitive decline in patients with epilepsy. The treatment of interictal symptoms will increase the quality of life of many patients with epilepsy.
Collapse
Affiliation(s)
- Sandra Schipper
- Department of Clinical Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands; Faculty of Health Medicine & Life Sciences, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands.
| | - Marlien W Aalbers
- Faculty of Health Medicine & Life Sciences, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands; University of Groningen, University Medical Center Groningen, Department of Neurosurgery, The Netherlands
| | - Kim Rijkers
- Faculty of Health Medicine & Life Sciences, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Neurosurgery, Zuyderland Medical Center, Heerlen, The Netherlands
| | - Melanie Lagiere
- Faculty of Health Medicine & Life Sciences, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Jan G Bogaarts
- Department of Clinical Neurophysiology, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Arjan Blokland
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Sylvia Klinkenberg
- Department of Clinical Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands; Faculty of Health Medicine & Life Sciences, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Govert Hoogland
- Faculty of Health Medicine & Life Sciences, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands; Department of Neurosurgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Johan S H Vles
- Department of Clinical Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands; Faculty of Health Medicine & Life Sciences, School of Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands
| |
Collapse
|
28
|
Sharma AK, Reams RY, Jordan WH, Miller MA, Thacker HL, Snyder PW. Mesial Temporal Lobe Epilepsy: Pathogenesis, Induced Rodent Models and Lesions. Toxicol Pathol 2016; 35:984-99. [PMID: 18098044 DOI: 10.1080/01926230701748305] [Citation(s) in RCA: 195] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Mesial temporal lobe epilepsy (MTLE), the most common epilepsy in adults, is generally intractable and is suspected to be the result of recurrent excitation or inhibition circuitry. Recurrent excitation and the development of seizures have been associated with aberrant mossy fiber sprouting in the hippocampus. Of the animal models developed to investigate the pathogenesis of MTLE, post-status epilepticus models have received the greatest acceptance because they are characterized by a latency period, the development of spontaneous motor seizures, and a spectrum of lesions like those of MTLE. Among post-status epilepticus models, induction of systemic kainic acid or pilocarpine-induced epilepsy is less labor-intensive than electrical-stimulation models and these models mirror the clinicopathologic features of MTLE more closely than do kindling, tetanus toxin, hyperthermia, post-traumatic, and perinatal hypoxia/ischemia models. Unfortunately, spontaneous motor seizures do not develop in kindling or adult hyperthermia models and are not a consistent finding in tetanus toxin-induced or perinatal hypoxia/ischemia models. This review presents the mechanistic hypotheses for seizure induction, means of model induction, and associated pathology, especially as compared to MTLE patients. Animal models are valuable tools not only to study the pathogenesis of MTLE, but also to evaluate potential antiepileptogenic drugs.
Collapse
Affiliation(s)
- Alok K. Sharma
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
- Department of Pathology, Covance Laboratories Inc., Madison, WI, 53704, USA
| | - Rachel Y. Reams
- Department of Pathology, Lilly Research Laboratories, Division of Eli Lilly and Co., Greenfield, IN, 46140, USA
| | - William H. Jordan
- Department of Pathology, Lilly Research Laboratories, Division of Eli Lilly and Co., Greenfield, IN, 46140, USA
| | - Margaret A. Miller
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
| | - H. Leon Thacker
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
| | - Paul W. Snyder
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
| |
Collapse
|
29
|
Relationship between seizure frequency and number of neuronal and non-neuronal cells in the hippocampus throughout the life of rats with epilepsy. Brain Res 2016; 1634:179-186. [PMID: 26764534 DOI: 10.1016/j.brainres.2015.12.055] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 12/11/2015] [Accepted: 12/26/2015] [Indexed: 11/22/2022]
Abstract
The relationship between seizure frequency and cell death has been a subject of controversy. To tackle this issue, we determined the frequency of seizures and the total number of hippocampal cells throughout the life of rats with epilepsy using the pilocarpine model. Seizure frequency varied in animals with epilepsy according to which period of life they were in, with a progressive increase in the number of seizures until 180 days (sixth months) of epileptic life followed by a decrease (330 days-eleventh month) and subsequently stabilization of seizures. Cell counts by means of isotropic fractionation showed a reduction in the number of hippocampal neuronal cells following 30, 90, 180 and 360 days of spontaneous recurrent seizures (SRS) in rats compared to their controls (about 25%-30% of neuronal cell reduction). In addition, animals with 360 days of SRS showed a reduction in the number of neuronal cells when compared with animals with 90 and 180 days of seizures. The total number of hippocampal non-neuronal cells was reduced in rats with epilepsy after 30 days of SRS, but no significant alteration was observed on the 90th, 180th and 360th days. The total number of neuronal cells was negatively correlated with seizure frequency, indicating an association between occurrence of epileptic seizures throughout life and neuronal loss. In sum, our results add novel data to the literature concerning the time-course of SRS and hippocampal cell number throughout epileptic life.
Collapse
|
30
|
Continuous neurodegeneration and death pathway activation in neurons and glia in an experimental model of severe chronic epilepsy. Neurobiol Dis 2015; 83:54-66. [PMID: 26264964 DOI: 10.1016/j.nbd.2015.08.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 07/21/2015] [Accepted: 08/05/2015] [Indexed: 12/17/2022] Open
Abstract
Whether seizures might determine the activation of cell death pathways and what could be the relevance of seizure-induced cell death in epilepsy are still highly debated issues. We recently developed an experimental model of acquired focal cortical dysplasia (the MAM-pilocarpine or MP rat) in which the occurrence of status epilepticus--SE--and subsequent seizures induced progressive cellular/molecular abnormalities and neocortical/hippocampal atrophy. Here, we exploited the same model to verify when, where, and how cell death occurred in neurons and glia during epilepsy course. We analyzed Fluoro Jade (FJ) staining and the activation of c-Jun- and caspase-3-dependent pathways during epilepsy, from few hours post-SE up to six months of spontaneous recurrent seizures. FJ staining revealed that cell injury in MP rats was not temporally restricted to SE, but extended throughout the different epileptic stages. The region-specific pattern of FJ staining changed during epilepsy, and FJ(+) neurons became more prominent in the dorsal and ventral hippocampal CA at chronic epilepsy stages. Phospho-c-Jun- and caspase-3-dependent pathways were selectively activated respectively in neurons and glia, at early but even more conspicuously at late chronic stages. Phospho-c-Jun activation was associated with increased cytochrome-c staining, particularly at chronic stages, and the staining pattern of cytochrome-c was suggestive of its release from the mitochondria. Taken together, these data support the content that at least in the MP rat model the recurrence of seizures can also sustain cell death mechanisms, thus continuously contributing to the pathologic process triggered by the occurrence of SE.
Collapse
|
31
|
Gorter JA, van Vliet EA, Lopes da Silva FH. Which insights have we gained from the kindling and post-status epilepticus models? J Neurosci Methods 2015; 260:96-108. [PMID: 25842270 DOI: 10.1016/j.jneumeth.2015.03.025] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 11/24/2022]
Abstract
Experimental animal epilepsy research got a big boost since the discovery that daily mild and short (seconds) tetanic stimulations in selected brain regions led to seizures with increasing duration and severity. This model that was developed by Goddard (1967) became known as the kindling model for epileptogenesis and has become a widely used model for temporal lobe epilepsy with complex partial seizures. During the late ninety-eighties the number of publications related to electrical kindling reached its maximum. However, since the kindling procedure is rather labor intensive and animals only develop spontaneous seizures (epilepsy) after hundreds of stimulations, research has shifted toward models in which the animals exhibit spontaneous seizures after a relatively short latent period. This led to post-status epilepticus (SE) models in which animals experience SE after injection of pharmacological compounds (e.g. kainate or pilocarpine) or via electrical stimulation of (limbic) brain regions. These post-SE models are the most widely used models in epilepsy research today. However, not all aspects of mesial temporal lobe epilepsy (MTLE) are reproduced and the widespread brain damage is often a caricature of the situation in the patient. Therefore, there is a need for models that can better replicate the disease. Kindling, although already a classic model, can still offer valid clues in this context. In this paper, we review different aspects of the kindling model with emphasis on experiments in the rat. Next, we review characteristic properties of the post-SE models and compare the neuropathological, electrophysiological and molecular differences between kindling and post-SE epilepsy models. Finally, we shortly discuss the advantages and disadvantages of these models.
Collapse
Affiliation(s)
- Jan A Gorter
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands.
| | - Erwin A van Vliet
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Fernando H Lopes da Silva
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands; Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal
| |
Collapse
|
32
|
Gorter JA, Iyer A, White I, Colzi A, van Vliet EA, Sisodiya S, Aronica E. Hippocampal subregion-specific microRNA expression during epileptogenesis in experimental temporal lobe epilepsy. Neurobiol Dis 2014; 62:508-20. [DOI: 10.1016/j.nbd.2013.10.026] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 10/11/2013] [Accepted: 10/24/2013] [Indexed: 11/25/2022] Open
|
33
|
Kantorovich S, Astary GW, King MA, Mareci TH, Sarntinoranont M, Carney PR. Influence of neuropathology on convection-enhanced delivery in the rat hippocampus. PLoS One 2013; 8:e80606. [PMID: 24260433 PMCID: PMC3832660 DOI: 10.1371/journal.pone.0080606] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 10/03/2013] [Indexed: 01/08/2023] Open
Abstract
Local drug delivery techniques, such as convention-enhanced delivery (CED), are promising novel strategies for delivering therapeutic agents otherwise limited by systemic toxicity and blood-brain-barrier restrictions. CED uses positive pressure to deliver infusate homogeneously into interstitial space, but its distribution is dependent upon appropriate tissue targeting and underlying neuroarchitecture. To investigate effects of local tissue pathology and associated edema on infusate distribution, CED was applied to the hippocampi of rats that underwent electrically-induced, self-sustaining status epilepticus (SE), a prolonged seizure. Infusion occurred 24 hours post-SE, using a macromolecular tracer, the magnetic resonance (MR) contrast agent gadolinium chelated with diethylene triamine penta-acetic acid and covalently attached to albumin (Gd-albumin). High-resolution T1- and T2-relaxation-weighted MR images were acquired at 11.1 Tesla in vivo prior to infusion to generate baseline contrast enhancement images and visualize morphological changes, respectively. T1-weighted imaging was repeated post-infusion to visualize final contrast-agent distribution profiles. Histological analysis was performed following imaging to characterize injury. Infusions of Gd-albumin into injured hippocampi resulted in larger distribution volumes that correlated with increased injury severity, as measured by hyperintense regions seen in T2-weighted images and corresponding histological assessments of neuronal degeneration, myelin degradation, astrocytosis, and microglial activation. Edematous regions included the CA3 hippocampal subfield, ventral subiculum, piriform and entorhinal cortex, amygdalar nuclei, middle and laterodorsal/lateroposterior thalamic nuclei. This study demonstrates MR-visualized injury processes are reflective of cellular alterations that influence local distribution volume, and provides a quantitative basis for the planning of local therapeutic delivery strategies in pathological brain regions.
Collapse
Affiliation(s)
- Svetlana Kantorovich
- Department of Neuroscience, University of Florida, Gainesville, Florida, United States of America
- Wilder Center of Excellence for Epilepsy Research, University of Florida, Gainesville, Florida, United States of America
- Department of Pediatrics, Division of Pediatric Neurology, University of Florida, Gainesville, Florida, United States of America
| | - Garrett W. Astary
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, United States of America
| | - Michael A. King
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida, United States of America
- Malcom Randall Veterans Affairs Medical Center, Gainesville, University of Florida, Gainesville, Florida, United States of America
| | - Thomas H. Mareci
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida, United States of America
| | - Malisa Sarntinoranont
- Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida, United States of America
| | - Paul R. Carney
- Department of Neuroscience, University of Florida, Gainesville, Florida, United States of America
- Wilder Center of Excellence for Epilepsy Research, University of Florida, Gainesville, Florida, United States of America
- Department of Pediatrics, Division of Pediatric Neurology, University of Florida, Gainesville, Florida, United States of America
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, United States of America
| |
Collapse
|
34
|
Sakurai M, Morita T, Takeuchi T, Shimada A. Relationship of angiogenesis and microglial activation to seizure-induced neuronal death in the cerebral cortex of Shetland Sheepdogs with familial epilepsy. Am J Vet Res 2013; 74:763-70. [PMID: 23627390 DOI: 10.2460/ajvr.74.5.763] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether angiogenesis and microglial activation were related to seizure-induced neuronal death in the cerebral cortex of Shetland Sheepdogs with familial epilepsy. ANIMALS Cadavers of 10 Shetland Sheepdogs from the same family (6 dogs with seizures and 4 dogs without seizures) and 4 age-matched unrelated Shetland Sheepdogs. PROCEDURES Samples of brain tissues were collected after euthanasia and then fixed in neutral phosphate-buffered 10% formalin and routinely embedded in paraffin. The fixed samples were sectioned for H&E staining and immunohistochemical analysis. RESULTS Evidence of seizure-induced neuronal death was detected exclusively in samples of cerebral cortical tissue from the dogs with familial epilepsy in which seizures had been observed. The seizure-induced neuronal death was restricted to tissues from the cingulate cortex and sulci surrounding the cerebral cortex. In almost the same locations as where seizure-induced neuronal death was identified, microvessels appeared longer and more tortuous and the number of microvessels was greater than in the dogs without seizures and control dogs. Occasionally, the microvessels were surrounded by oval to flat cells, which had positive immunohistochemical results for von Willebrand factor. Immunohistochemical results for neurons and glial cells (astrocytes and microglia) were positive for vascular endothelial growth factor, and microglia positive for ionized calcium-binding adapter molecule 1 were activated (ie, had swollen cell bodies and long processes) in almost all the same locations as where seizure-induced neuronal death was detected. Double-label immunofluorescence techniques revealed that the activated microglia had positive results for tumor necrosis factor-α, interleukin-6, and vascular endothelial growth factor receptor 1. These findings were not observed in the cerebrum of dogs without seizures, whether the dogs were from the same family as those with epilepsy or were unrelated to them. CONCLUSIONS AND CLINICAL RELEVANCE Signs of angiogenesis and microglial activation corresponded with seizure-induced neuronal death in the cerebral cortex of Shetland Sheepdogs with familial epilepsy. Microglial activation induced by vascular endothelial growth factor and associated proinflammatory cytokine production may accelerate seizure-induced neuronal death in dogs with epilepsy.
Collapse
Affiliation(s)
- Masashi Sakurai
- Department of Veterinary Pathology, Faculty of Agriculture, Tottori University, Tottori, Tottori 680-8553, Japan
| | | | | | | |
Collapse
|
35
|
Bielefeld P, van Vliet EA, Gorter JA, Lucassen PJ, Fitzsimons CP. Different subsets of newborn granule cells: a possible role in epileptogenesis? Eur J Neurosci 2013; 39:1-11. [DOI: 10.1111/ejn.12387] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Revised: 09/03/2013] [Accepted: 09/10/2013] [Indexed: 12/27/2022]
Affiliation(s)
- Pascal Bielefeld
- Center for Neuroscience; Swammerdam Institute for Life Sciences; University of Amsterdam; Science Park 904 1098 XH Amsterdam The Netherlands
| | - Erwin A. van Vliet
- Center for Neuroscience; Swammerdam Institute for Life Sciences; University of Amsterdam; Science Park 904 1098 XH Amsterdam The Netherlands
- Epilepsy Institute in The Netherlands Foundation (Stichting Epilepsie Instellingen Nederland SEIN); Heemstede The Netherlands
| | - Jan A. Gorter
- Center for Neuroscience; Swammerdam Institute for Life Sciences; University of Amsterdam; Science Park 904 1098 XH Amsterdam The Netherlands
| | - Paul J. Lucassen
- Center for Neuroscience; Swammerdam Institute for Life Sciences; University of Amsterdam; Science Park 904 1098 XH Amsterdam The Netherlands
| | - Carlos P. Fitzsimons
- Center for Neuroscience; Swammerdam Institute for Life Sciences; University of Amsterdam; Science Park 904 1098 XH Amsterdam The Netherlands
| |
Collapse
|
36
|
Saxena T, Karumbaiah L, Gaupp EA, Patkar R, Patil K, Betancur M, Stanley GB, Bellamkonda RV. The impact of chronic blood–brain barrier breach on intracortical electrode function. Biomaterials 2013; 34:4703-13. [DOI: 10.1016/j.biomaterials.2013.03.007] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 03/03/2013] [Indexed: 02/01/2023]
|
37
|
Stanley DA, Talathi SS, Parekh MB, Cordiner DJ, Zhou J, Mareci TH, Ditto WL, Carney PR. Phase shift in the 24-hour rhythm of hippocampal EEG spiking activity in a rat model of temporal lobe epilepsy. J Neurophysiol 2013; 110:1070-86. [PMID: 23678009 DOI: 10.1152/jn.00911.2012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
For over a century epileptic seizures have been known to cluster at specific times of the day. Recent studies have suggested that the circadian regulatory system may become permanently altered in epilepsy, but little is known about how this affects neural activity and the daily pattern of seizures. To investigate, we tracked long-term changes in the rate of spontaneous hippocampal EEG spikes (SPKs) in a rat model of temporal lobe epilepsy. In healthy animals, SPKs oscillated with near 24-h period; however, after injury by status epilepticus, a persistent phase shift of ∼12 h emerged in animals that later went on to develop chronic spontaneous seizures. Additional measurements showed that global 24-h rhythms, including core body temperature and theta state transitions, did not phase shift. Instead, we hypothesized that locally impaired circadian input to the hippocampus might be responsible for the SPK phase shift. This was investigated with a biophysical computer model in which we showed that subtle changes in the relative strengths of circadian input could produce a phase shift in hippocampal neural activity. MRI provided evidence that the medial septum, a putative circadian relay center for the hippocampus, exhibits signs of damage and therefore could contribute to local circadian impairment. Our results suggest that balanced circadian input is critical to maintaining natural circadian phase in the hippocampus and that damage to circadian relay centers, such as the medial septum, may disrupt this balance. We conclude by discussing how abnormal circadian regulation may contribute to the daily rhythms of epileptic seizures and related cognitive dysfunction.
Collapse
Affiliation(s)
- David A Stanley
- Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Dedeurwaerdere S, Fang K, Chow M, Shen YT, Noordman I, van Raay L, Faggian N, Porritt M, Egan G, O'Brien T. Manganese-enhanced MRI reflects seizure outcome in a model for mesial temporal lobe epilepsy. Neuroimage 2013; 68:30-8. [DOI: 10.1016/j.neuroimage.2012.11.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 11/23/2012] [Indexed: 10/27/2022] Open
|
39
|
Mazzuferi M, Kumar G, Rospo C, Kaminski RM. Rapid epileptogenesis in the mouse pilocarpine model: Video-EEG, pharmacokinetic and histopathological characterization. Exp Neurol 2012; 238:156-67. [DOI: 10.1016/j.expneurol.2012.08.022] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 07/31/2012] [Accepted: 08/21/2012] [Indexed: 01/08/2023]
|
40
|
Chang L, Zhang X, Liu W, Song Y, Gao X, Ling W, Wu Y. Immunoreactivity of Ki-67/β-tubulin and immunocolocalization with active caspase-3 in rat dentate gyrus during postnatal development. J Chem Neuroanat 2012; 46:10-8. [PMID: 22959929 DOI: 10.1016/j.jchemneu.2012.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2012] [Revised: 08/25/2012] [Accepted: 08/25/2012] [Indexed: 11/30/2022]
Abstract
This study was based on our previous report that the expression of active caspase-3 kept at a high level in dentate gyrus during postnatal development, which is not related to an apoptotic event. We addressed the hypothesis that the active caspase-3 expression may be related to a nonapoptotic role in the regulation of the cell cycle and differentiation or other physiological functions. To confirm this hypothesis, through a temporal investigation from postnatal day (P) 0, 4, 7, 10, 14, 21, 28, to 56, based on immunofluorescent method, we dual labeled active caspase-3 with Ki-67 or β-tubulin in the dentate gyrus. Our results showed a minority of active caspase-3 positive cells were colabeled with the proliferation marker Ki-67 in stratum moleculare (MOL), granular cell layer (GCL), subgranular zone (SGZ) and polymorphic stratum (POLY) from P0 to P14, and the colabeled cells decreased gradually with age. From P21 to P56, the colocalization of the two proteins was mainly focused on SGZ. There was a positive correlation between the positive cells of active caspase-3 with that of Ki-67. In addition, an extensive colocalization between active caspase-3 and β-tubulin was observed at all the age groups. There was a strong positive correlation between the intensity of active caspase-3 in GCL with that of β-tubulin in MOL, GCL and POLY of dentate gyrus and the stratum lucidum of CA3. Our data raised the possibility of a nonapoptotic role of active caspase-3 in dentate gyrus, which may be partly associated with cellular proliferation and differentiation, and also may be related to neurite outgrowth, axonal transport, or dendrite elongation of granular cells during postnatal development.
Collapse
Affiliation(s)
- Lirong Chang
- Department of Anatomy, Capital Medical University, Beijing, China
| | | | | | | | | | | | | |
Collapse
|
41
|
Li LY, Li JL, Zhang HM, Yang WM, Wang K, Fang Y, Wang Y. TGFβ1 treatment reduces hippocampal damage, spontaneous recurrent seizures, and learning memory deficits in pilocarpine-treated rats. J Mol Neurosci 2012; 50:109-23. [PMID: 22936246 DOI: 10.1007/s12031-012-9879-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Accepted: 08/15/2012] [Indexed: 11/28/2022]
Abstract
Studies have demonstrated the neuroprotective activity of transforming growth factor beta-1 (TGFβ1), protecting neurons against different kinds of insults. However, the role of exogenous TGFβ1 in the neuronal damage following status epilepticus (SE) and the related spontaneous recurrent seizures (SRS) is unknown. The present study aimed to determine the effect of intranasal TGFβ1 administration on SRS and cognitive function following lithium-pilocarpine-induced SE and associated hippocampal damage. We found that intranasal TGFβ1 significantly attenuated the hippocampal insults marked by hematoxylin and eosin, terminal deoxynucleotidyl transferase dUTP nick end labeling, and Fluoro-Jade B staining by 24, 48, and 72 h after SE was induced. The expression of the apoptosis-suppressing protein, Bcl-2, was elevated, whereas the expression of the apoptosis-promoting proteins, Bax and Caspase-3, was suppressed in TGFβ1-treated rats compared to rats without TGFβ1 treatment by 24, 48, and 72 h following induction of SE. The seizure number, severity, and duration of SRS over a 1-month period of monitoring starting 15 days after SE induction as well as the cognitive deficits detected 45 days after SE induction were significantly reduced in TGFβ1-treated rats compared to those without TGFβ1 treatment. Our results indicate that intranasal delivery of TGFβ1 immediately after SE induction not only protected against SRS but also improved cognitive function. The anti-epileptogenic properties of TGFβ1 may be related to its effect of neuroprotection or to its effect of apoptosis pathway changes.
Collapse
Affiliation(s)
- Liang-Yong Li
- Epilepsy and Headache Group, Department of Neurology, the First Hospital of Anhui Medical University, Jixi Road 218, Hefei 230022, China
| | | | | | | | | | | | | |
Collapse
|
42
|
Kilany A, Raouf ERA, Gaber AA, Aloush TK, Aref HA, Anwar M, Henshall DC, Abdulghani MO. Elevated serum Bcl-2 in children with temporal lobe epilepsy. Seizure 2012; 21:250-3. [DOI: 10.1016/j.seizure.2012.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 01/11/2012] [Accepted: 01/14/2012] [Indexed: 11/15/2022] Open
|
43
|
Lee EM, Park GY, Im KC, Kim ST, Woo CW, Chung JH, Kim KS, Kim JS, Shon YM, Kim YI, Kang JK. Changes in glucose metabolism and metabolites during the epileptogenic process in the lithium-pilocarpine model of epilepsy. Epilepsia 2012; 53:860-9. [PMID: 22429025 DOI: 10.1111/j.1528-1167.2012.03432.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE The metabolic and biochemical changes that occur during epileptogenesis remain to be determined. (18) F-Fluorodeoxyglucose positron emission tomography (FDG-PET) and proton magnetic resonance spectroscopy ((1) H MRS) are noninvasive techniques that provide indirect information on ongoing pathologic changes. We, therefore, utilized these methods to assess changes in glucose metabolism and metabolites in the rat lithium-pilocarpine model of epilepsy as markers of epileptogenesis from baseline to chronic spontaneous recurrent seizures (SRS). METHODS PET and MRS were performed at baseline, and during the acute, subacute, silent, and chronic periods after lithium-pilocarpine induced status epilepticus (SE). Sequential changes in glucose metabolism on (18) F-FDG PET using SPM2 and the ratios of percent injected dose per gram (%ID)/g of regions of interest (ROIs) in the bilateral amygdala, hippocampus, basal ganglia with the thalamus, cortex, and hypothalamus normalized to the pons were determined. Voxels of interest (VOIs) on (1) H MRS were obtained at the right hippocampus and the basal ganglia. NAA/Cr levels and Cho/Cr at various time points were compared to baseline values. KEY FINDINGS Of 81 male Sprague-Dawley rats, 30 progressed to SRS. (18) F-FDG PET showed widespread global hypometabolism during the acute period, returning to baseline level during the subacute period. Glucose metabolism, however, declined in part of the hippocampus during the silent period, with the hypometabolic area progressively expanding to the entire limbic area during the chronic period. (1) H MRS showed that the NAA/Cr levels in the hippocampus and basal ganglia were reduced during the acute period and were not restored subsequently from the subacute to the chronic period without any significant change in the Cho/Cr ratio throughout the entire experiment. SIGNIFICANCE Serial metabolic and biochemical changes in the lithium-pilocarpine model of epilepsy indirectly represent the process of human epileptogenesis. Following initial irreversible neural damage by SE, global glucose metabolism transiently recovered during the subacute period without neuronal recovery. Progressive glucose hypometabolism in the limbic area during the silent and chronic periods may reflect the important role of the hippocampus in the formation of ongoing epileptic network during epileptogenesis.
Collapse
Affiliation(s)
- Eun Mi Lee
- Department of Neurology, Ulsan University Hospital, Ulsan, Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Upreti C, Otero R, Partida C, Skinner F, Thakker R, Pacheco LF, Zhou ZY, Maglakelidze G, Velíšková J, Velíšek L, Romanovicz D, Jones T, Stanton PK, Garrido-Sanabria ER. Altered neurotransmitter release, vesicle recycling and presynaptic structure in the pilocarpine model of temporal lobe epilepsy. ACTA ACUST UNITED AC 2012; 135:869-85. [PMID: 22344585 DOI: 10.1093/brain/awr341] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In searching for persistent seizure-induced alterations in brain function that might be causally related to epilepsy, presynaptic transmitter release has relatively been neglected. To measure directly the long-term effects of pilocarpine-induced status epilepticus on vesicular release and recycling in hippocampal mossy fibre presynaptic boutons, we used (i) two-photon imaging of FM1-43 vesicular release in rat hippocampal slices; and (ii) transgenic mice expressing the genetically encoded pH-sensitive fluorescent reporter synaptopHluorin preferentially at glutamatergic synapses. In this study we found that, 1-2 months after pilocarpine-induced status epilepticus, there were significant increases in mossy fibre bouton size, faster rates of action potential-driven vesicular release and endocytosis. We also analysed the ultrastructure of rat mossy fibre boutons using transmission electron microscopy. Pilocarpine-induced status epilepticus led to a significant increase in the number of release sites, active zone length, postsynaptic density area and number of vesicles in the readily releasable and recycling pools, all correlated with increased release probability. Our data show that presynaptic release machinery is persistently altered in structure and function by status epilepticus, which could contribute to the development of the chronic epileptic state and may represent a potential new target for antiepileptic therapies.
Collapse
Affiliation(s)
- Chirag Upreti
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY 10595, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
O'Dell CM, Das A, Wallace G, Ray SK, Banik NL. Understanding the basic mechanisms underlying seizures in mesial temporal lobe epilepsy and possible therapeutic targets: a review. J Neurosci Res 2012; 90:913-24. [PMID: 22315182 DOI: 10.1002/jnr.22829] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 10/05/2011] [Accepted: 10/09/2011] [Indexed: 12/13/2022]
Abstract
Despite years of research, epilepsy remains a poorly understood disorder. In the past several years, work has been conducted on a variety of projects with the goal of better understanding the pathogenesis and progression of mesial temporal lobe epilepsy (MTLE), in particular, and how to exploit those properties to generate innovative therapies for treatment of refractory epilepsies. This review seeks to give an overview of common morphological and biochemical changes associated with epilepsy and proposed treatments to address those changes. Furthering the understanding of ictogenesis and epileptogenesis remains an important goal for scientists seeking to find more effective treatments for MTLE.
Collapse
Affiliation(s)
- Casey M O'Dell
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | | | | | | | | |
Collapse
|
46
|
|
47
|
Cardoso A, Lukoyanova EA, Madeira MD, Lukoyanov NV. Seizure-induced structural and functional changes in the rat hippocampal formation: Comparison between brief seizures and status epilepticus. Behav Brain Res 2011; 225:538-46. [DOI: 10.1016/j.bbr.2011.07.057] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 07/28/2011] [Accepted: 07/30/2011] [Indexed: 12/28/2022]
|
48
|
Sloviter RS. Progress on the issue of excitotoxic injury modification vs. real neuroprotection; implications for post-traumatic epilepsy. Neuropharmacology 2011; 61:1048-50. [PMID: 21839755 DOI: 10.1016/j.neuropharm.2011.07.038] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 07/27/2011] [Indexed: 11/17/2022]
Affiliation(s)
- Robert S Sloviter
- Department of Pharmacology, University of Arizona College of Medicine, Tucson, AZ 85724-5050, USA.
| |
Collapse
|
49
|
Complement protein 6 deficiency in PVG/c rats does not lead to neuroprotection against seizure induced cell death. Neuroscience 2011; 188:109-16. [DOI: 10.1016/j.neuroscience.2011.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Revised: 04/28/2011] [Accepted: 05/01/2011] [Indexed: 02/05/2023]
|
50
|
Weissberg I, Reichert A, Heinemann U, Friedman A. Blood-brain barrier dysfunction in epileptogenesis of the temporal lobe. EPILEPSY RESEARCH AND TREATMENT 2011; 2011:143908. [PMID: 22937228 PMCID: PMC3420538 DOI: 10.1155/2011/143908] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 03/14/2011] [Indexed: 01/16/2023]
Abstract
Epilepsy of the temporal lobe (TLE) is the most common form of focal epilepsy, and in adults, it most frequently develops after injury. However, the mechanisms by which a normal functioning brain turns into an epileptic one still remain obscure. Recent studies point to vascular involvement and particularly blood-brain barrier (BBB) dysfunction in the development of epilepsy. The BBB is a specialized structure which functions to control the neuronal extracellular milieu. BBB dysfunction is found in many diseases of the central nervous system, including stroke, traumatic injuries, tumors and infections. Interestingly, all these insults may initiate an epileptogenic process which eventually leads to spontaneous, recurrent seizures. This epileptogenic time frame usually lasts weeks, months, or even years in man, and days to weeks in rodents and may serve as a "window of opportunity" for the prevention of epilepsy. However, no prevention strategy exists, stressing the importance of research into the mechanisms of epileptogenesis. Here, we will underscore recent experiments suggesting that BBB dysfunction directly induces epileptogenesis. We will provide new evidence to support the hypothesis that BBB breakdown and specifically exposure of temporal lobe structures to the most common serum protein, albumin, is sufficient to induce epileptogenesis.
Collapse
Affiliation(s)
- Itai Weissberg
- Departments of Physiology and Neurobiology, Ben-Gurion University of the Negev, Beersheva 84105, Israel
| | - Aljoscha Reichert
- Neurocure Research Center, Institute of Neurophysiology, Charité Universitätsmedizin, Berlin 10117, Germany
| | - Uwe Heinemann
- Neurocure Research Center, Institute of Neurophysiology, Charité Universitätsmedizin, Berlin 10117, Germany
| | - Alon Friedman
- Departments of Physiology and Neurobiology, Ben-Gurion University of the Negev, Beersheva 84105, Israel
- Neurocure Research Center, Institute of Neurophysiology, Charité Universitätsmedizin, Berlin 10117, Germany
- Biomedical Engineering, Ben-Gurion University of the Negev, Beersheva 84105, Israel
| |
Collapse
|