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Katsarou AM, Kubova H, Auvin S, Mantegazza M, Barker-Haliski M, Galanopoulou AS, Reid CA, Semple BD. A companion to the preclinical common data elements for rodent models of pediatric acquired epilepsy: A report of the TASK3-WG1B, Pediatric and Genetic Models Working Group of the ILAE/AES Joint Translational Task Force. Epilepsia Open 2022. [PMID: 35950641 DOI: 10.1002/epi4.12641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 02/08/2022] [Indexed: 11/05/2022] Open
Abstract
Epilepsy syndromes during the early years of life may be attributed to an acquired insult, such as hypoxic-ischemic injury, infection, status epilepticus, or brain trauma. These conditions are frequently modeled in experimental rodents to delineate mechanisms of epileptogenesis and investigate novel therapeutic strategies. However, heterogeneity and subsequent lack of reproducibility of such models across laboratories is an ongoing challenge to maintain scientific rigor and knowledge advancement. To address this, as part of the TASK3-WG1B Working Group of the International League Against Epilepsy/American Epilepsy Society Joint Translational Task Force, we have developed a series of case report forms (CRFs) to describe common data elements for pediatric acquired epilepsy models in rodents. The "Rodent Models of Pediatric Acquired Epilepsy" Core CRF was designed to capture cohort-general information; while two Specific CRFs encompass physical induction models and chemical induction models, respectively. This companion manuscript describes the key elements of these models and why they are important to be considered and reported consistently. Together, these CRFs provide investigators with the tools to systematically record critical information regarding their chosen model of acquired epilepsy during early life, for improved standardization and transparency across laboratories. These outcomes will support the ultimate goal of such research; that is, to understand the childhood onset-specific biology of epileptogenesis after acquired insults, and translate this knowledge into therapeutics to improve pediatric patient outcomes and minimize the lifetime burden of epilepsy.
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Affiliation(s)
- Anna-Maria Katsarou
- Laboratory of Developmental Epilepsy, Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Hana Kubova
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Stéphane Auvin
- Service de Neurologie Pédiatrique, Hôpital Robert-Debré, INSERM UMR 1141, APHP, Université de Paris, Paris, France
- Institut Universitaire de France (IUF), Paris, France
| | - Massimo Mantegazza
- Inserm, LabEx ICST, Institute of Molecular and Cellular Pharmacology (IPMC), CNRS UMR7275, Université Côte d'Azur, Valbonne-Sophia Antipolis, France
| | - Melissa Barker-Haliski
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Aristea S Galanopoulou
- Laboratory of Developmental Epilepsy, Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, USA
- Isabelle Rapin Division of Child Neurology, Laboratory of Developmental Epilepsy, Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Christopher A Reid
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Bridgette D Semple
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- Department of Neurology, Alfred Health, Prahran, Victoria, Australia
- Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Parkville, Victoria, Australia
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Dutton SBB, Dutt K, Papale LA, Helmers S, Goldin AL, Escayg A. Early-life febrile seizures worsen adult phenotypes in Scn1a mutants. Exp Neurol 2017; 293:159-171. [PMID: 28373025 DOI: 10.1016/j.expneurol.2017.03.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 02/17/2017] [Accepted: 03/22/2017] [Indexed: 01/27/2023]
Abstract
Mutations in the voltage-gated sodium channel (VGSC) gene SCN1A, encoding the Nav1.1 channel, are responsible for a number of epilepsy disorders including genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome (DS). Patients with SCN1A mutations often experience prolonged early-life febrile seizures (FSs), raising the possibility that these events may influence epileptogenesis and lead to more severe adult phenotypes. To test this hypothesis, we subjected 21-23-day-old mice expressing the human SCN1A GEFS+ mutation R1648H to prolonged hyperthermia, and then examined seizure and behavioral phenotypes during adulthood. We found that early-life FSs resulted in lower latencies to induced seizures, increased severity of spontaneous seizures, hyperactivity, and impairments in social behavior and recognition memory during adulthood. Biophysical analysis of brain slice preparations revealed an increase in epileptiform activity in CA3 pyramidal neurons along with increased action potential firing, providing a mechanistic basis for the observed worsening of adult phenotypes. These findings demonstrate the long-term negative impact of early-life FSs on disease outcomes. This has important implications for the clinical management of this patient population and highlights the need for therapeutic interventions that could ameliorate disease progression.
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Affiliation(s)
- Stacey B B Dutton
- Department of Human Genetics, Emory University, Atlanta, GA 30022, USA; Department of Biology, Agnes Scott College, Atlanta, GA 30030, USA
| | - Karoni Dutt
- Departments of Microbiology & Molecular Genetics and Anatomy & Neurobiology, University of California, Irvine, CA 92697, USA
| | - Ligia A Papale
- Department of Human Genetics, Emory University, Atlanta, GA 30022, USA
| | - Sandra Helmers
- Department of Neurology, Emory University, Atlanta, GA 30022, USA
| | - Alan L Goldin
- Departments of Microbiology & Molecular Genetics and Anatomy & Neurobiology, University of California, Irvine, CA 92697, USA
| | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, GA 30022, USA.
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Tao K, Ichikawa J, Matsuki N, Ikegaya Y, Koyama R. Experimental febrile seizures induce age-dependent structural plasticity and improve memory in mice. Neuroscience 2016; 318:34-44. [DOI: 10.1016/j.neuroscience.2016.01.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 01/06/2016] [Accepted: 01/06/2016] [Indexed: 01/06/2023]
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Huang WX, Yu F, Sanchez RM, Liu YQ, Min JW, Hu JJ, Bsoul NB, Han S, Yin J, Liu WH, He XH, Peng BW. TRPV1 promotes repetitive febrile seizures by pro-inflammatory cytokines in immature brain. Brain Behav Immun 2015; 48:68-77. [PMID: 25801060 DOI: 10.1016/j.bbi.2015.01.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 01/22/2015] [Accepted: 01/26/2015] [Indexed: 10/23/2022] Open
Abstract
Febrile seizure (FS) is the most common seizure disorder in children, and children with FS are regarded as a high risk for the eventual development of epilepsy. Brain inflammation may be implicated in the mechanism of FS. Transient receptor potential vanilloid 1 (TRPV1) is believed to act as a monitor and regulator of body temperature. The role of inflammation in synaptic plasticity mediation indicates that TRPV1 is relevant to several nervous system diseases, such as epilepsy. Here, we report a critical role for TRPV1 in a febrile seizure mouse model and reveal increased levels of pro-inflammatory factors in the immature brain. Animals were subjected to hyperthermia for 30 min, which generates seizures lasting approximately 20 min, and then were used for experiments. To invoke frequently repetitive febrile seizures, mice are exposed to hyperthermia for three times daily at an interval of 4h between every time induced seizure, and a total of 4 days to induce. Behavioral testing for febrile seizures revealed that a TRPV1 knock-out mouse model demonstrated a prolonged onset latency and a shortened duration and seizure grade of febrile seizure when compared with wild type (WT) mice. The expression levels of both TRPV1 mRNA and protein increased after a hyperthermia-induced febrile seizure in WT mice. Notably, TRPV1 activation resulted in a significant elevation in the expression of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and HMGB1) in the hippocampus and cortex. These data indicate that the reduction of TRPV1 expression parallels a decreased susceptibility to febrile seizures. Thus, preventative strategies might be developed for use during febrile seizures.
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Affiliation(s)
- Wen-Xian Huang
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Fang Yu
- Department of Pathology, Zhongnan Hospital, Wuhan University, Wuhan 430071, China
| | - Russell M Sanchez
- Dept of Surgery, College of Medicine, Texas A&M Health Science Center, Neuroscience Institute, Scott & White Hospital, & Central Texas Veterans Health Care System, Temple, TX, United States
| | - Yu-Qiang Liu
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Jia-Wei Min
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Jiang-Jian Hu
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Najeeb Bassam Bsoul
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Song Han
- Department of Pathophysiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Jun Yin
- Department of Pathophysiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Wan-Hong Liu
- Department of Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China
| | - Xiao-Hua He
- Department of Pathophysiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China.
| | - Bi-Wen Peng
- Department of Physiology, Hubei Provincial Key Laboratory of Developmentally Originated Disorder, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China.
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Patterson KP, Baram TZ, Shinnar S. Origins of temporal lobe epilepsy: febrile seizures and febrile status epilepticus. Neurotherapeutics 2014; 11:242-50. [PMID: 24604424 PMCID: PMC3996115 DOI: 10.1007/s13311-014-0263-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Temporal lobe epilepsy (TLE) and hippocampal sclerosis (HS) commonly arise following early-life long seizures, and especially febrile status epilepticus (FSE). However, there are major gaps in our knowledge regarding the causal relationships of FSE, TLE, HS and cognitive disturbances that hamper diagnosis, biomarker development and prevention. The critical questions include: What is the true probability of developing TLE after FSE? Are there predictive markers for those at risk? A fundamental question is whether FSE is simply a marker of individuals who are destined to develop TLE, or if FSE contributes to the risk of developing TLE. If FSE does contribute to epileptogenesis, then does this happen only in the setting of a predisposed brain? These questions are addressed within this review, using information gleaned over the past two decades from clinical studies as well as animal models.
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Affiliation(s)
- Katelin P. Patterson
- />Department of Anatomy and Neurobiology, University of California-Irvine, Irvine, CA USA
| | - Tallie Z. Baram
- />Department of Anatomy and Neurobiology, University of California-Irvine, Irvine, CA USA
- />Department of Pediatrics, University of California-Irvine, Irvine, CA USA
- />Department of Neurology, University of California-Irvine Medical Center, Irvine, CA USA
| | - Shlomo Shinnar
- />Department of Neurology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY USA
- />Department of Pediatrics, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY USA
- />Department of Epidemiology and Population Health, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY USA
- />Comprehensive Epilepsy Management Center, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY USA
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Kong WL, Min JW, Liu YL, Li JX, He XH, Peng BW. Role of TRPV1 in susceptibility to PTZ-induced seizure following repeated hyperthermia challenges in neonatal mice. Epilepsy Behav 2014; 31:276-80. [PMID: 24269027 DOI: 10.1016/j.yebeh.2013.10.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 10/13/2013] [Accepted: 10/14/2013] [Indexed: 11/27/2022]
Abstract
This study was designed to investigate the role of experimental febrile seizures in the induction of generalized clonic seizures and the involvement of heat-sensitive channel TRPV1. Pentylenetetrazol-induced clonic seizure was used as the seizure model, and Trpv1 gene knock-out and wild-type C57/BL6 mice were used as experimental subjects. Electroencephalograph and seizure behavior were recorded for the evaluation of the severity of seizures. Increased frequency of the experimental febrile seizures facilitated PTZ-induced generalized clonic seizures. Trpv1 gene deficiency decreased the properties of generalized clonic seizure. The intensity of experimental febrile seizures reduced the threshold to generalized clonic seizure, and Trpv1 gene deficiency decreased the susceptibility to PTZ-induced seizures following early-life hyperthermia challenges in mice.
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Affiliation(s)
- Wei-Lin Kong
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China.
| | - Jia-Wei Min
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China.
| | - Yuan-Lin Liu
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China.
| | - Jun-Xu Li
- Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA.
| | - Xiao-Hua He
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China.
| | - Bi-Wen Peng
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China.
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Rajab E, Abdeen Z, Hassan Z, Alsaffar Y, Mandeel M, Al Shawaaf F, Al-Ansari S, Kamal A. Cognitive performance and convulsion risk after experimentally-induced febrile-seizures in rat. Int J Dev Neurosci 2014; 34:19-23. [PMID: 24433986 DOI: 10.1016/j.ijdevneu.2014.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 01/04/2014] [Accepted: 01/04/2014] [Indexed: 02/05/2023] Open
Abstract
Many reports indicated that small percentage of children with febrile seizures develop epilepsy and cognitive disorders later in adulthood. In addition, the neuronal network of the hippocampus was reported to be deranged in adult animals after being exposed to hyperthermia-induced seizures in their neonatal life. The aims of this study were to investigate (1) latency and probability of seizures, (2) spatial learning and memory, in adult rats after neonatal hyperthermia-induced febrile seizures (FS). Prolonged FS were elicited in 10-day old, male Sprague Dawleys (n=11/group) by exposure to heated air (48-52 °C) for 30 min; control rats were exposed to 30 °C air. After 1.5 months the animal's cognitive performance was assessed by 5 day trial in the Morris water maze. In another experiment the latency and probability of seizures were measured in response to pentylenetetrazole (PTZ) injections (increased doses ranged from 7 to 140 mg/kg; i.p.). In water maze, both groups showed improvements in escape latency and distance swam to reach the platform; effects were significantly greater in control versus hyperthermia-treated animals on days 3 and 4. Latency and probability of PTZ-induced seizures were shorter and higher respectively, in hyperthermia-treated animals compared to controls. We concluded that FS in neonatal rats leads to enhanced susceptibility for seizures, as well as cognitive deficits in adults.
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Affiliation(s)
- Ebrahim Rajab
- College of Medical & Health Sciences, Ahlia University, P.O. Box 10878, Manama, Bahrain
| | - Zahra Abdeen
- Physiology Department, College of Medicine and Medical Sciences, Arabian Gulf University, P.O. Box 22979, Manama, Bahrain
| | - Zuhair Hassan
- Physiology Department, College of Medicine and Medical Sciences, Arabian Gulf University, P.O. Box 22979, Manama, Bahrain
| | - Yousif Alsaffar
- Physiology Department, College of Medicine and Medical Sciences, Arabian Gulf University, P.O. Box 22979, Manama, Bahrain
| | - Mohammad Mandeel
- Physiology Department, College of Medicine and Medical Sciences, Arabian Gulf University, P.O. Box 22979, Manama, Bahrain
| | - Fatima Al Shawaaf
- Physiology Department, College of Medicine and Medical Sciences, Arabian Gulf University, P.O. Box 22979, Manama, Bahrain
| | - Sali Al-Ansari
- University Medical Centre of Groningen (UMCG), Groningen University, The Netherlands
| | - Amer Kamal
- Physiology Department, College of Medicine and Medical Sciences, Arabian Gulf University, P.O. Box 22979, Manama, Bahrain.
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Gholipoor P, Saboory E, Roshan-Milani S, Fereidoni J. Effect of hyperthermia on histamine blood level and convulsive behavior in infant rats. Epilepsy Behav 2013; 29:269-74. [PMID: 24051280 DOI: 10.1016/j.yebeh.2013.07.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2013] [Revised: 06/26/2013] [Accepted: 07/30/2013] [Indexed: 10/26/2022]
Abstract
Febrile seizures (FS), which have been extensively studied using animal models, are the most common type of convulsive events in children, but the cellular mechanisms causing FS are still unclear. Histamine has been suggested to participate in seizure control. This study investigated the effect of hyperthermia (HT) on histamine blood level (HBL) and convulsive behavior in prepubertal rats. Forty Wistar rat pups were assigned to 5 groups (n=8), namely, control, HT, cromolyn, chlorpheniramine, and ranitidine. Two groups of adult rats were also used as control and HT adults. The control rats were placed in a hyperthermic chamber, and a room temperature current of air was blown on them. In all other groups, the rats were placed in the chamber for 30 min, and a current of warm air was applied to them. In the pretreatment groups, the rats received an injection of 68-mg/kg cromolyn sodium, 4-mg/kg chlorpheniramine, or 80-mg/kg ranitidine intraperitoneally 30 min prior to HT. Body temperature and convulsive behaviors were recorded. Then, the rats were anesthetized with ether, and their blood sample was obtained through direct heart puncture. Hyperthermia initiated convulsive behaviors in infant rats but not in the adult ones. Pretreatment with chlorpheniramine significantly potentiated convulsive behaviors (p=0.017). Hyperthermia led to a significant decrease in the HBL of both infant (p<0.001) and adult (p=0.003) rats. Pretreatments led to more decrease in the HBL of infant rats (p<0.001). It was concluded that HT could lead to a decrease in HBL, which in turn increases the seizure susceptibility of animals. Histamine may have a pivotal role in hyperthermia-induced seizures.
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Affiliation(s)
- Peyman Gholipoor
- Department of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
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A prolonged experimental febrile seizure results in motor map reorganization in adulthood. Neurobiol Dis 2011; 45:692-700. [PMID: 22044736 DOI: 10.1016/j.nbd.2011.10.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 09/22/2011] [Accepted: 10/16/2011] [Indexed: 01/24/2023] Open
Abstract
INTRODUCTION Clinical studies have suggested that children experiencing a febrile seizure (FS) before the age of 1year have persistent deficits, but it is unknown whether these seizures lead to permanent cortical reorganization and alterations in function. A FS on the background of increased genetic seizure susceptibility may also lead to negative long-term consequences. Alterations in neocortical motor map expression provide a measure of neocortical reorganization and have been reported in both adults with frontal lobe epilepsy and following seizure induction in experimental models. The objectives of the present study were to determine whether (1) an infantile FS leads to changes to motor map expression in adulthood; (2) long-term cortical reorganization is a function of the age at FS or genetic seizure susceptibility; and (3) different levels of GABA(A) or glutamate receptor subunits or cation-chloride-co-transporters (CCCs) at the time of FS correlate with alterations to motor map expression. MATERIALS AND METHODS FSs were induced in postnatal day 10 (P10) or P14 Long-Evans (LE) rats or in P14 seizure-prone FAST rats by the administration of the bacterial endotoxin lipopolysaccharide (LPS) and a subconvulsant dose of kainic acid. Ten weeks later intracortical microstimulation was performed to generate motor maps of forelimb movement representations. Sensorimotor neocortex samples were also dissected from naïve P10 FAST and P10 and P14 LE pups for western blotting with antibodies against various GABA(A), NMDA, and AMPA receptor subunits and for CCCs. RESULTS Adult FAST rats had larger motor maps with lower stimulation thresholds after a FS at P14, while adult LE rats had significantly lower map stimulation thresholds but similar sized maps after a FS at P10 compared to controls. There were no differences in neocortical motor map size or stimulation thresholds in adult LE rats after a FS at P14. Both P10 LE and P14 FAST rats had significantly lower levels of the GABA(A) receptor α1 subunit, higher levels of the α2 subunit, and a higher NKCC1/KCC2 ratio in the sensorimotor cortex compared with the P14 LE rat. In addition, the P14 FAST rats had lower levels of the GluR2 and NR2A receptor subunits in the sensorimotor cortex compared with the P14 LE rats. CONCLUSIONS A single infantile FS can have long-term effects on neocortical reorganization in younger individuals and those with underlying seizure susceptibility. These changes may be related to an increased level of excitability in the neocortex of younger or genetically seizure-prone rats, as suggested by immaturity of their GABAergic and CCC systems. Given the high incidence of FSs in children, it will be important to gain a better understanding of how age and genetic seizure predisposition may contribute to the long-term sequelae of these events.
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McClelland S, Dubé CM, Yang J, Baram TZ. Epileptogenesis after prolonged febrile seizures: mechanisms, biomarkers and therapeutic opportunities. Neurosci Lett 2011; 497:155-62. [PMID: 21356275 DOI: 10.1016/j.neulet.2011.02.032] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 02/15/2011] [Indexed: 01/08/2023]
Abstract
Epidemiological and recent prospective analyses of long febrile seizures (FS) and febrile status epilepticus (FSE) support the idea that in some children, such seizures can provoke temporal lobe epilepsy (TLE). Because of the high prevalence of these seizures, if epilepsy was to arise as their direct consequence, this would constitute a significant clinical problem. Here we discuss these issues, and describe the use of animal models of prolonged FS and of FSE to address the following questions: Are long FS epileptogenic? What governs this epileptogenesis? What are the mechanisms? Are there any predictive biomarkers of the epileptogenic process, and can these be utilized, together with information about the mechanisms of epileptogenesis, for eventual prevention of the TLE that results from long FS and FSE.
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Affiliation(s)
- Shawn McClelland
- Department of Anatomy/Neurobiology, University of California, Irvine, CA 92697-4475, USA
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Rijkers K, Mescheriakova J, Majoie M, Lemmens E, van Wijk X, Philippens M, Van Kranen-Mastenbroek V, Schijns O, Vles J, Hoogland G. Polymorphisms in CACNA1E and Camk2d are associated with seizure susceptibility of Sprague-Dawley rats. Epilepsy Res 2010; 91:28-34. [PMID: 20638246 DOI: 10.1016/j.eplepsyres.2010.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 04/29/2010] [Accepted: 06/10/2010] [Indexed: 10/19/2022]
Abstract
Seizures are associated with high intracellular calcium levels. However, conditions characterized by high intracellular calcium levels, such as stroke or traumatic brain injury, do not always evoke epilepsy. We hypothesized that polymorphisms in calcium-related genes CACNA1E and Camk2d contribute to the individual variability in seizure susceptibility. The distribution of one single nucleotide polymorphism (SNP) in the CACNA1E and one in the Camk2d gene was determined in Sprague-Dawley rats that were subjected to amygdala kindling or hyperthermia-induced seizures. The pre-kindling afterdischarge threshold was significantly lower in rats with the CACNA1E GG genotype (45.2+/-6.7microA) than in the GT genotyped animals (79.3+/-53.7microA). Among hyperthermia treated rats, the Camk2d G allele was more frequent among rats that did not display behavioral seizures during hyperthermia (67%) than in animals that did show behavioral seizures during hyperthermia (52%, chi(2)(1)=3.847, p=0.05). SNPs in CACNA1E and Camk2d genes are associated with the individual variability in seizure susceptibility in two experimental seizure models.
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Affiliation(s)
- Kim Rijkers
- Department of Neurosurgery, University Medical Center Maastricht, Maastricht, The Netherlands.
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Notenboom RGE, Ramakers GMJ, Kamal A, Spruijt BM, de Graan PNE. Long-lasting modulation of synaptic plasticity in rat hippocampus after early-life complex febrile seizures. Eur J Neurosci 2010; 32:749-58. [PMID: 20646062 DOI: 10.1111/j.1460-9568.2010.07321.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A small fraction of children with febrile seizures appears to develop cognitive impairments. Recent studies in a rat model of hyperthermia-induced febrile seizures indicate that prolonged febrile seizures early in life have long-lasting effects on the hippocampus and induce cognitive deficits. However, data on network plasticity and the nature of cognitive deficits are conflicting. We examined three specific measures of hippocampal plasticity in adult rats with a prior history of experimental febrile seizures: (i) activity-dependent synaptic plasticity (long-term potentiation and depression) by electrophysiological recordings of Schaffer collateral/commissural-evoked field excitatory synaptic potentials in CA1 of acute hippocampal slices; (ii) Morris water maze spatial learning and memory; and (iii) hippocampal mossy fiber plasticity by Timm histochemistry and quantification of terminal sprouting in CA3 and the dentate gyrus. We found enhanced hippocampal CA1 long-term potentiation and reduced long-term depression but normal spatial learning and memory in adult rats that were subjected to experimental febrile seizures on postnatal day 10. Furthermore, rats with experimental febrile seizures showed modest but significant sprouting of mossy fiber collaterals into the inner molecular layer of the dentate gyrus in adulthood. We conclude that enhanced CA1 long-term potentiation and mild mossy fiber sprouting occur after experimental febrile seizures, without affecting spatial learning and memory in the Morris water maze. These long-term functional and structural alterations in hippocampal plasticity are likely to play a role in the enhanced seizure susceptibility in this model of prolonged human febrile seizures but do not correlate with overt cognitive deficits.
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Affiliation(s)
- Robbert G E Notenboom
- Rudolf Magnus Institute of Neuroscience, Department of Neuroscience & Pharmacology, University Medical Center Utrecht, Utrecht, The Netherlands.
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Abstract
Febrile seizures (FSs) are seizures that occur during fever, usually at the time of a cold or flu, and represent the most common cause of seizures in the pediatric population. Up to 5% of children between the ages of six months and five years-of-age will experience a FS. Clinically these seizures are categorized as benign events with little impact on the growth and development of the child. However, studies have linked the occurrence of FSs to an increased risk of developing adult epileptic disorders. There are many unanswered questions about FSs, such as the mechanism of their generation, the long-term effects of these seizures, and their role in epileptogenesis. Answers are beginning to emerge based on results from animal studies. This review summarizes the current literature on animal models of FSs, mechanisms underlying the seizures, and functional, structural, and molecular changes that may result from them.
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