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Santana-Coelho D, Pranske ZJ, Nolan SO, Hodges SL, Binder MS, Womble PD, Narvaiz DA, Muhammad I, Lugo JN. Neonatal immune stimulation results in sex-specific changes in ultrasonic vocalizations but does not affect seizure susceptibility in neonatal mice. Int J Dev Neurosci 2024; 84:381-391. [PMID: 38712612 DOI: 10.1002/jdn.10333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 04/15/2024] [Accepted: 04/19/2024] [Indexed: 05/08/2024] Open
Abstract
Neuroinflammation during the neonatal period has been linked to disorders such as autism and epilepsy. In this study, we investigated the early life behavioral consequences of a single injection of lipopolysaccharide (LPS) at postnatal day 10 (PD10) in mice. To assess deficits in communication, we performed the isolation-induced ultrasonic vocalizations (USVs) test at PD12. To determine if early life immune stimulus could alter seizure susceptibility, latency to flurothyl-induced generalized seizures was measured at 4 hours (hrs), 2 days, or 5 days after LPS injections. LPS had a sex-dependent effect on USV number. LPS-treated male mice presented significantly fewer USVs than LPS-treated female mice. However, the number of calls did not significantly differ between control and LPS for either sex. In male mice, we found that downward, short, and composite calls were significantly more prevalent in the LPS treatment group, while upward, chevron, and complex calls were less prevalent than in controls (p < 0.05). Female mice that received LPS presented a significantly higher proportion of short, frequency steps, two-syllable, and composite calls in their repertoire when compared with female control mice (p < 0.05). Seizure latency was not altered by early-life inflammation at any of the time points measured. Our findings suggest that early-life immune stimulation at PD10 disrupts vocal development but does not alter the susceptibility to flurothyl-induced seizures during the neonatal period. Additionally, the effect of inflammation in the disruption of vocalization is sex-dependent.
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Affiliation(s)
| | - Zachary J Pranske
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - Suzanne O Nolan
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | | | - Matthew S Binder
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - Paige D Womble
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - David A Narvaiz
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - Ilyasah Muhammad
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
| | - Joaquin N Lugo
- Department of Psychology and Neuroscience, Baylor University, Waco, Texas, USA
- Institute of Biomedical Studets, Waco, Texas, USA
- Department of Biology, Baylor University, Waco, Texas, USA
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2
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Wu W, Song W, Zhao J, Guo S, Hong M, Zheng J, Hua Y, Cao P, Liu R, Duan JA. Saiga antelope horn suppresses febrile seizures in rats by regulating neurotransmitters and the arachidonic acid pathway. Chin Med 2024; 19:78. [PMID: 38831318 PMCID: PMC11149251 DOI: 10.1186/s13020-024-00949-3] [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: 04/11/2024] [Accepted: 05/21/2024] [Indexed: 06/05/2024] Open
Abstract
BACKGROUND Saiga antelope horn (SAH) is a traditional Chinese medicine for treating febrile seizure (FS) with precise efficacy, but its mechanism of action and functional substances are still unclear. Given the need for further research on SAH, our group conducted studies to elucidate its mechanisms and active substances. METHODS An FS rat pup model was constructed through intraperitoneal injection of LPS and hyperthermia induction. Behavioural indicators of seizures, hippocampal histopathological alterations, serum levels of inflammatory cytokines and hippocampal levels of neurotransmitters were observed and measured to investigate the effects of SAH on FS model rats. Hippocampal metabolomics and network pharmacology analyses were conducted to reveal the differential metabolites, key peptides and pathways involved in the suppression of FS by SAH. RESULTS SAH suppressed FS, decreased the inflammatory response and regulated the Glu-GABA balance. Metabolomic analysis revealed 13 biomarkers of FS, of which SAH improved the levels of 8 differential metabolites. Combined with network pharmacology, a "biomarker-core target-key peptide" network was constructed. The peptides of SAH, such as YGQL and LTGGF, could exert therapeutic effects via the arachidonic acid pathway. Molecular docking and ELISA results indicated that functional peptides of SAH could bind to PTGS2 target, inhibiting the generation of AA and its metabolites in hippocampal samples. CONCLUSION In summary, the functional peptides contained in SAH are the main material basis for the treatment of FS, potentially acting through neurotransmitter regulation and the arachidonic acid pathway.
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Affiliation(s)
- Wenxing Wu
- National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, and Jiangsu Key Laboratory for High Technology Research of Traditional Chinese Medicine Formulae, Nanjing University of Chinese Medicine, No 138 Xianlin Road, Nanjing, 210023, China
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
- Animal-Derived Chinese Medicine and Functional Peptides International Collaboration Joint Laboratory, Nanjing, 210023, China
| | - Wencong Song
- National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, and Jiangsu Key Laboratory for High Technology Research of Traditional Chinese Medicine Formulae, Nanjing University of Chinese Medicine, No 138 Xianlin Road, Nanjing, 210023, China
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Jingjing Zhao
- National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, and Jiangsu Key Laboratory for High Technology Research of Traditional Chinese Medicine Formulae, Nanjing University of Chinese Medicine, No 138 Xianlin Road, Nanjing, 210023, China
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Sheng Guo
- National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, and Jiangsu Key Laboratory for High Technology Research of Traditional Chinese Medicine Formulae, Nanjing University of Chinese Medicine, No 138 Xianlin Road, Nanjing, 210023, China
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Min Hong
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Jie Zheng
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Yongqing Hua
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Peng Cao
- National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, and Jiangsu Key Laboratory for High Technology Research of Traditional Chinese Medicine Formulae, Nanjing University of Chinese Medicine, No 138 Xianlin Road, Nanjing, 210023, China
- Animal-Derived Chinese Medicine and Functional Peptides International Collaboration Joint Laboratory, Nanjing, 210023, China
| | - Rui Liu
- National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, and Jiangsu Key Laboratory for High Technology Research of Traditional Chinese Medicine Formulae, Nanjing University of Chinese Medicine, No 138 Xianlin Road, Nanjing, 210023, China.
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
- Animal-Derived Chinese Medicine and Functional Peptides International Collaboration Joint Laboratory, Nanjing, 210023, China.
| | - Jin-Ao Duan
- National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, and Jiangsu Key Laboratory for High Technology Research of Traditional Chinese Medicine Formulae, Nanjing University of Chinese Medicine, No 138 Xianlin Road, Nanjing, 210023, China.
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, China.
- Animal-Derived Chinese Medicine and Functional Peptides International Collaboration Joint Laboratory, Nanjing, 210023, China.
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3
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Faidi R, Reid AY. Early-life immune activation is a vulnerability factor for adult epileptogenesis in neurofibromatosis type 1 in male mice. Front Neurol 2024; 15:1284574. [PMID: 38685949 PMCID: PMC11056566 DOI: 10.3389/fneur.2024.1284574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 03/28/2024] [Indexed: 05/02/2024] Open
Abstract
Introduction Patients with Neurofibromatosis type 1 (NF1), the most common neurocutaneous disorder, can develop several neurological manifestations that include cognitive impairments and epilepsy over their lifetime. It is unclear why certain patients with NF1 develop these conditions while others do not. Early-life immune activation promotes later-life seizure susceptibility, neurocognitive impairments, and leads to spontaneous seizures in some animal models of neurodevelopmental disorders, but the central nervous system immune profile and the enduring consequences of early-life immune activation on the developmental trajectory of the brain in NF1 have not yet been explored. We tested the hypothesis that early-life immune activation promotes the development of spatial memory impairments and epileptogenesis in a mouse model of NF1. Methods Male wild-type (WT) and Nf1+/- mice received systemic lipopolysaccharide (LPS) or saline at post-natal day 10 and were assessed in adulthood for learning and memory deficits in the Barnes maze and underwent EEG recordings to look for spontaneous epileptiform abnormalities and susceptibility to challenge with pentylenetetrazole (PTZ). Results Whereas early-life immune activation by a single injection of LPS acutely elicited a comparable brain cytokine signature in WT and Nf1+/- mice, it promoted spontaneous seizure activity in adulthood only in the Nf1+/- mice. Early-life immune activation affected susceptibility to PTZ-induced seizures similarly in both WT and Nf1+/-mice. There was no effect on spatial learning and memory regardless of mouse genotype. Discussion Our findings suggest second-hit environmental events such as early-life immune activation may promote epileptogenesis in the Nf1+/- mouse and may be a risk-factor for NF1-associated epilepsy.
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Affiliation(s)
- Rania Faidi
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Aylin Y. Reid
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
- Division of Neurology, University of Toronto, Toronto, ON, Canada
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Kloc ML, Chen Y, Daglian JM, Holmes GL, Baram TZ, Barry JM. Spatial learning impairments and discoordination of entorhinal-hippocampal circuit coding following prolonged febrile seizures. Hippocampus 2023; 33:970-992. [PMID: 37096324 PMCID: PMC10529121 DOI: 10.1002/hipo.23541] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 03/30/2023] [Accepted: 04/08/2023] [Indexed: 04/26/2023]
Abstract
How the development and function of neural circuits governing learning and memory are affected by insults in early life remains poorly understood. The goal of this study was to identify putative changes in cortico-hippocampal signaling mechanisms that could lead to learning and memory deficits in a clinically relevant developmental pathophysiological rodent model, Febrile status epilepticus (FSE). FSE in both pediatric cases and the experimental animal model, is associated with enduring physiological alterations of the hippocampal circuit and cognitive impairment. Here, we deconstruct hippocampal circuit throughput by inducing slow theta oscillations in rats under urethane anesthesia and isolating the dendritic compartments of CA1 and dentate gyrus subfields, their reception of medial and lateral entorhinal cortex inputs, and the efficacy of signal propagation to each somatic cell layer. We identify FSE-induced theta-gamma decoupling at cortical synaptic input pathways and altered signal phase coherence along the CA1 and dentate gyrus somatodendritic axes. Moreover, increased DG synaptic activity levels are predictive of poor cognitive outcomes. We propose that these alterations in cortico-hippocampal coordination interfere with the ability of hippocampal dendrites to receive, decode and propagate neocortical inputs. If this frequency-specific syntax is necessary for cortico-hippocampal coordination and spatial learning and memory, its loss could be a mechanism for FSE cognitive comorbidities.
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Affiliation(s)
- Michelle L. Kloc
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
| | - Yuncai Chen
- Departments of Pediatrics, University California-Irvine, Irvine, California, USA
- Departments of Anatomy/Neurobiology, University California-Irvine, Irvine, California, USA
| | - Jennifer M. Daglian
- Departments of Pediatrics, University California-Irvine, Irvine, California, USA
| | - Gregory L. Holmes
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
| | - Tallie Z. Baram
- Departments of Pediatrics, University California-Irvine, Irvine, California, USA
- Departments of Anatomy/Neurobiology, University California-Irvine, Irvine, California, USA
- Departments of Neurology, University California-Irvine, Irvine, California, USA
| | - Jeremy M. Barry
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
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Crocker CE, Sharmeen R, Tran TT, Khan AM, Li W, Alcorn JL. Surfactant protein a attenuates generalized and localized neuroinflammation in neonatal mice. Brain Res 2023; 1807:148308. [PMID: 36871846 PMCID: PMC10065943 DOI: 10.1016/j.brainres.2023.148308] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023]
Abstract
Surfactant protein A (SP-A) has important roles in innate immunity and modulation of pulmonary and extrapulmonary inflammation. Given SP-A has been detected in rat and human brain, we sought to determine if SP-A has a role in modulating inflammation in the neonatal mouse brain. Neonatal wildtype (WT) and SP-A-deficient (SP-A-/-) mice were subjected to three models of brain inflammation: systemic sepsis, intraventricular hemorrhage (IVH) and hypoxic-ischemic encephalopathy (HIE). Following each intervention, RNA was isolated from brain tissue and expression of cytokine and SP-A mRNA was determined by real-time quantitative RT-PCR analysis. In the sepsis model, expression of most cytokine mRNAs was significantly increased in brains of WT and SP-A-/- mice with significantly greater expression of all cytokine mRNA levels in SP-A-/- mice compared to WT. In the IVH model, expression of all cytokine mRNAs was significantly increased in WT and SP-A-/- mice and levels of most cytokine mRNAs were significantly increased in SP-A-/- mice compared to WT. In the HIE model, only TNF-α mRNA levels were significantly increased in WT brain tissue while all pro-inflammtory cytokine mRNAs were significantly increased in SP-A-/- mice, and all pro-inflammatory cytokine mRNA levels were significantly higher in SP-A-/- mice compared to WT. SP-A mRNA was not detectable in brain tissue of adult WT mice nor in WT neonates subjected to these models. These results suggest that SP-A-/- neonatal mice subjected to models of neuroinflammation are more susceptible to both generalized and localized neuroinflammation compared to WT mice, thus supporting the hypothesis that SP-A attenuates inflammation in neonatal mouse brain.
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Affiliation(s)
- Caroline E Crocker
- Division of Neonatology, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Romana Sharmeen
- Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Thu T Tran
- Division of Neonatology, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Amir M Khan
- Division of Neonatology, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Wen Li
- Division of Clinical and Translational Sciences, Department of Internal Medicine, the University of Texas McGovern Medical School at Houston, Houston, TX 77030, USA; Biostatistics/Epidemiology/Research Design Component, Center for Clinical and Translational Sciences, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Joseph L Alcorn
- Division of Neonatology, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA; Pediatric Research Center, Department of Pediatrics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
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Maikoo S, Wilkins A, Qulu L. The effect of oxytocin and an enriched environment on anxiety-like behaviour and corticosterone levels in a prenatally stressed febrile seizure rat model. IBRO Neurosci Rep 2022; 13:47-56. [PMID: 36590100 PMCID: PMC9795298 DOI: 10.1016/j.ibneur.2022.05.001] [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: 05/17/2021] [Revised: 04/30/2022] [Accepted: 05/03/2022] [Indexed: 02/01/2023] Open
Abstract
Background Febrile seizures (FS) are a neurological abnormality which occur following a fever that has resulted from a systemic infection and are characterised by convulsions. These convulsions occur due to abnormally increased signalling of interleukin-1 beta, resulting in increased neuronal hyper-excitability. Furthermore, exposure to prenatal stress has been shown to exacerbate seizure duration, elicit anxiety-like behaviour and corticosterone levels. Oxytocin is a neuropeptide with anxiolytic, social bonding, and stress regulation effects. Therefore, the aim of the study was to assess whether oxytocin can attenuate the anxiety-like behaviour and increased corticosterone in rat offspring exposed to prenatal stress and FS. Method Sprague Dawley rats were mated. On GND14, prenatal stress was induced on pregnant dams for 1 hr/7 days. On PND 14, rat pups were injected with lipopolysaccharide (LPS, 200 μg/kg, i.p.) followed 2.5 h later by an i.p. injection of kainic acid (KA, 1.75 mg/kg). Oxytocin (1 mg/kg) was induced via different routes (intraperitoneal or intranasal) as well an enriched environment between PND 22-26. The enriched environment included larger cages (1560 cm2) with only 4 pups per cage, compared to those groups not receiving enrichment (646 cm2), as well as cardboard rolls and plastic toys. On PND 27-33 the light/dark box and elevated plus maze were used to assess anxiety-like behaviour. On PND 34 all rats were euthanized using a sharp guillotine, trunk blood and hypothalamic tissue were collected for neurochemical analysis (ELISA kit). Results Our findings confirmed that exposure to both prenatal stress and febrile seizures resulted anxiety-like behaviour and significantly higher plasma corticosterone concentrations compared to their counterparts. Environmental enrichment was significantly effective in attenuating the increased basal corticosterone levels and anxiety-like behaviour seen in the prenatally stressed FS rat. Although direct administration of oxytocin showed higher significance in reducing corticosterone plasma levels when compared to the enriched environment. Furthermore, hypothalamic oxytocin levels were not significant in rat exposed to environmental enrichment while oxytocin treatment showed a significant effect when compared to their counterparts. Conclusion Therefore, oxytocin administration during early postnatal development shows great potential in reversing the effects of prenatal stress and its subsequent exacerbation of FS.
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Affiliation(s)
- Shreyal Maikoo
- HIV Pathogenesis Programme, Doris Duke Medical Research Institute, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Andria Wilkins
- University of KwaZulu-Natal, College of Health Sciences, Department of Human Physiology, Durban, South Africa
| | - Lihle Qulu
- Stellenbosch University - Tygerberg Campus: Stellenbosch University Faculty of Medicine and Health Sciences, Capetown, South Africa,Corresponding author.
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Batulin D, Lagzi F, Vezzani A, Jedlicka P, Triesch J. A mathematical model of neuroimmune interactions in epileptogenesis for discovering treatment strategies. iScience 2022; 25:104343. [PMID: 35601918 PMCID: PMC9121278 DOI: 10.1016/j.isci.2022.104343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 12/22/2021] [Accepted: 04/25/2022] [Indexed: 11/16/2022] Open
Abstract
The development of epilepsy (epileptogenesis) involves a complex interplay of neuronal and immune processes. Here, we present a first-of-its-kind mathematical model to better understand the relationships among these processes. Our model describes the interaction between neuroinflammation, blood-brain barrier disruption, neuronal loss, circuit remodeling, and seizures. Formulated as a system of nonlinear differential equations, the model reproduces the available data from three animal models. The model successfully describes characteristic features of epileptogenesis such as its paradoxically long timescales (up to decades) despite short and transient injuries or the existence of qualitatively different outcomes for varying injury intensity. In line with the concept of degeneracy, our simulations reveal multiple routes toward epilepsy with neuronal loss as a sufficient but non-necessary component. Finally, we show that our model allows for in silico predictions of therapeutic strategies, revealing injury-specific therapeutic targets and optimal time windows for intervention. A dynamical systems model describes the development of epilepsy after different injuries Simulation results are in agreement with data from three animal models Model shows degeneracy: multiple distinct but linked mechanisms cause epileptogenesis Framework permits studying the effects of therapeutic interventions in silico
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Affiliation(s)
- Danylo Batulin
- Frankfurt Institute for Advanced Studies, Frankfurt 60438, Germany
- Faculty of Computer Science and Mathematics, Goethe University, Frankfurt 60486, Germany
- CePTER – Center for Personalized Translational Epilepsy Research, Frankfurt, Germany
- Corresponding author
| | - Fereshteh Lagzi
- Frankfurt Institute for Advanced Studies, Frankfurt 60438, Germany
- CePTER – Center for Personalized Translational Epilepsy Research, Frankfurt, Germany
- Center for Computational Neuroscience and Swartz Center for Theoretical Neuroscience, University of Washington, Seattle 98195, USA
- Department of Physiology and Biophysics, University of Washington, Seattle 98195, USA
| | - Annamaria Vezzani
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milano 20156, Italy
| | - Peter Jedlicka
- Frankfurt Institute for Advanced Studies, Frankfurt 60438, Germany
- CePTER – Center for Personalized Translational Epilepsy Research, Frankfurt, Germany
- ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus-Liebig-University, Giessen 35390, Germany
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University, Frankfurt 60528, Germany
- Corresponding author
| | - Jochen Triesch
- Frankfurt Institute for Advanced Studies, Frankfurt 60438, Germany
- Faculty of Computer Science and Mathematics, Goethe University, Frankfurt 60486, Germany
- CePTER – Center for Personalized Translational Epilepsy Research, Frankfurt, Germany
- Faculty of Physics, Goethe University, Frankfurt 60438, Germany
- Corresponding author
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Pittman QJ. Vasopressin and central control of the cardiovascular system: A 40-year retrospective. J Neuroendocrinol 2021; 33:e13011. [PMID: 34235812 DOI: 10.1111/jne.13011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 06/25/2021] [Indexed: 01/24/2023]
Abstract
In the 40 years since vasopressin (AVP) was reported to have a central action with respect to raising blood pressure, the finding has been repeatedly replicated using a variety of complimentary approaches. The role of AVP as a central neurotransmitter involved in control of the cardiovascular system is now textbook material. However, it is evident that brain AVP plays, at best, a minor role in regulation of normal blood pressure. However, it appears to be an important player in a several cardiovascular-associated pathologies, ranging from hypertension to neural changes associated with heart failure. There are many interventions that have been shown to affect neural function, many of which are associated with alterations in behaviour. Possible alterations in neuronal AVP actions relevant to cardiovascular control in the setting of chronic inflammatory disease, early-life stress and inflammation are suggested areas for future research.
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Affiliation(s)
- Quentin J Pittman
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
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9
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Increased Excitatory Synaptic Transmission Associated with Adult Seizure Vulnerability Induced by Early-Life Inflammation in Mice. J Neurosci 2021; 41:4367-4377. [PMID: 33827934 DOI: 10.1523/jneurosci.2667-20.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 03/24/2021] [Accepted: 03/28/2021] [Indexed: 12/27/2022] Open
Abstract
Early-life inflammatory stress increases seizure susceptibility later in life. However, possible sex- and age-specific differences and the associated mechanisms are largely unknown. C57BL/6 mice were bred in house, and female and male pups were injected with lipopolysaccharide (LPS; 100 μg/kg, i.p.) or vehicle control (saline solution) at postnatal day 14 (P14). Seizure threshold was assessed in response to pentylenetetrazol (1% solution, i.v.) in adolescence (∼P40) and adulthood (∼P60). We found that adult, but not adolescent, mice treated with LPS displayed ∼34% lower seizure threshold compared with controls. Females and males showed similar increased seizure susceptibility, suggesting that altered brain excitability was age dependent, but not sex dependent. Whole-cell recordings revealed no differences in excitatory synaptic activity onto CA1 pyramidal neurons from control or neonatally inflamed adolescent mice of either sex. However, adult mice of both sexes previously exposed to LPS displayed spontaneous EPSC frequency approximately twice that of controls, but amplitude was unchanged. Although these changes were not associated with alterations in dendritic spines or in the NMDA/AMPA receptor ratio, they were linked to an increased glutamate release probability from Schaffer collateral, but not temporoammonic pathway. This glutamate increase was associated with reduced activity of presynaptic GABAB receptors and was independent of the endocannabinoid-mediated suppression of excitation. Our new findings demonstrate that early-life inflammation leads to long-term increased hippocampal excitability in adult female and male mice associated with changes in glutamatergic synaptic transmission. These alterations may contribute to enhanced vulnerability of the brain to subsequent pathologic challenges such as epileptic seizures.SIGNIFICANCE STATEMENT Adult physiology has been shown to be affected by early-life inflammation. Our data reveal that early-life inflammation increases excitatory synaptic transmission onto hippocampal CA1 pyramidal neurons in an age-dependent manner through disrupted presynaptic GABAB receptor activity on Schaffer collaterals. This hyperexcitability was seen only in adult, and not in adolescent, animals of either sex. The data suggest a maturation process, independent of sex, in the priming action of early-life inflammation and highlight the importance of studying mature brains to reveal cellular changes associated with early-life interventions.
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Asisipo M, Gwladys NT, Musa MV. Effect of a novel prolonged febrile seizure model on GABA associated ion channels. Metab Brain Dis 2020; 35:441-449. [PMID: 31691144 DOI: 10.1007/s11011-019-00492-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 09/10/2019] [Indexed: 11/25/2022]
Abstract
Prolonged febrile seizures are usually modelled in animals using hyperthermia as an inducer. In this study, a modified simple febrile seizure model using a combination of lipopolysaccharide (LPS) and kainic acid (KA) was used to develop a prolonged febrile seizure animal model, which we used to assess effects on the expression of the sodium- potassium-chloride cotransporter 1 (NKCC1) and potassium-chloride cotransporter 2 (KCC2) and their possible role in seizure exacerbation. At post-natal day (PND) 14, rat pups were divided into a saline (S), simple febrile seizure (FSA-), prolonged febrile seizure (FSB-), saline A (SA+) and saline B (SB+) groups. SA+ and SB+ groups received different concentrations of KA (1.75 mg/kg, 1.83 μg/kg respectively) but no LPS. Changes in temperature, seizure activity and duration were recorded. Gene and protein expression of NKCC1, KCC2 and KCC2 phosphorylated serine (KCC2 ser) 940 were measured 1 h post seizure termination and on PND 15 using RT- PCR and western blot. There was an initial increase in temperature that was immediately followed by a temperature decrease and an increase in seizure severity and duration in the FSB- group. There was a decrease in KCC2 ser 940 protein expression. NKCC1 protein expression was increased in both FS groups suggesting decreased GABA receptor functionality. Therefore, the novel FSB- model resulted in more severe and sustained seizure activity by altering cotransporter gene and protein expression. This suggests that this model can be used to mimic prolonged febrile seizures and hence can be used to investigate the physiological changes accompanying this condition.
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Affiliation(s)
- Mohamed Asisipo
- Discipline of Human Physiology, School of Laboratory Medicine & Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, 4000, South Africa
| | - Ngoupaye Temkou Gwladys
- Department of Animal Biology, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
- Discipline of Human Physiology, School of Laboratory Medicine & Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, 4000, South Africa.
| | - Mabandla Vuyisile Musa
- Discipline of Human Physiology, School of Laboratory Medicine & Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, 4000, South Africa
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11
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Semple BD, Dill LK, O'Brien TJ. Immune Challenges and Seizures: How Do Early Life Insults Influence Epileptogenesis? Front Pharmacol 2020; 11:2. [PMID: 32116690 PMCID: PMC7010861 DOI: 10.3389/fphar.2020.00002] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 01/03/2020] [Indexed: 12/16/2022] Open
Abstract
The development of epilepsy, a process known as epileptogenesis, often occurs later in life following a prenatal or early postnatal insult such as cerebral ischemia, stroke, brain trauma, or infection. These insults share common pathophysiological pathways involving innate immune activation including neuroinflammation, which is proposed to play a critical role in epileptogenesis. This review provides a comprehensive overview of the latest preclinical evidence demonstrating that early life immune challenges influence neuronal hyperexcitability and predispose an individual to later life epilepsy. Here, we consider the range of brain insults that may promote the onset of chronic recurrent spontaneous seizures at adulthood, spanning intrauterine insults (e.g. maternal immune activation), perinatal injuries (e.g. hypoxic–ischemic injury, perinatal stroke), and insults sustained during early postnatal life—such as fever-induced febrile seizures, traumatic brain injuries, infections, and environmental stressors. Importantly, all of these insults represent, to some extent, an immune challenge, triggering innate immune activation and implicating both central and systemic inflammation as drivers of epileptogenesis. Increasing evidence suggests that pro-inflammatory cytokines such as interleukin-1 and subsequent signaling pathways are important mediators of seizure onset and recurrence, as well as neuronal network plasticity changes in this context. Our current understanding of how early life immune challenges prime microglia and astrocytes will be explored, as well as how developmental age is a critical determinant of seizure susceptibility. Finally, we will consider the paradoxical phenomenon of preconditioning, whereby these same insults may conversely provide neuroprotection. Together, an improved appreciation of the neuroinflammatory mechanisms underlying the long-term epilepsy risk following early life insults may provide insight into opportunities to develop novel immunological anti-epileptogenic therapeutic strategies.
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Affiliation(s)
- Bridgette D Semple
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia.,Department of Neurology, Alfred Health, Melbourne, VIC, Australia
| | - Larissa K Dill
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Neurology, Alfred Health, Melbourne, VIC, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Medicine, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC, Australia.,Department of Neurology, Alfred Health, Melbourne, VIC, Australia
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12
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Dexamethasone Attenuates Hyperexcitability Provoked by Experimental Febrile Status Epilepticus. eNeuro 2019; 6:ENEURO.0430-19.2019. [PMID: 31685676 PMCID: PMC6860985 DOI: 10.1523/eneuro.0430-19.2019] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 10/20/2019] [Indexed: 12/16/2022] Open
Abstract
The role of neuroinflammation in the mechanisms of epilepsy development is important because inflammatory mediators provide tractable targets for intervention. Inflammation is intrinsically involved in the generation of childhood febrile seizures (FSs), and prolonged FS [febrile status epilepticus (FSE)] precedes a large proportion of adult cases of temporal lobe epilepsy (TLE). As TLE is often refractory to therapy and is associated with serious cognitive and emotional problems, we investigated whether its development can be prevented using anti-inflammatory strategies. Using an immature rat model of FSE [experimental FSE (eFSE)], we administered dexamethasone (DEX), a broad anti-inflammatory agent, over 3 d following eFSE. We assessed eFSE-provoked hippocampal network hyperexcitability by quantifying the presence, frequency, and duration of hippocampal spike series, as these precede and herald the development of TLE-like epilepsy. We tested whether eFSE provoked hippocampal microgliosis, astrocytosis, and proinflammatory cytokine production in male and female rats and investigated blood–brain barrier (BBB) breaches as a potential contributor. We then evaluated whether DEX attenuated these eFSE sequelae. Spike series were not observed in control rats given vehicle or DEX, but occurred in 41.6% of eFSE-vehicle rats, associated with BBB leakage and elevated hippocampal cytokines. eFSE did not induce astrocytosis or microgliosis but provoked BBB disruption in 60% of animals. DEX significantly reduced spike series prevalence (to 7.6%) and frequency, and abrogated eFSE-induced cytokine production and BBB leakage (to 20%). These findings suggest that a short, postinsult intervention with a clinically available anti-inflammatory agent potently attenuates epilepsy-predicting hippocampal hyperexcitability, potentially by minimizing BBB disruption and related neuroinflammation.
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13
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Early Life Inflammation Increases CA1 Pyramidal Neuron Excitability in a Sex and Age Dependent Manner through a Chloride Homeostasis Disruption. J Neurosci 2019; 39:7244-7259. [PMID: 31308096 DOI: 10.1523/jneurosci.2973-18.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 05/31/2019] [Accepted: 07/04/2019] [Indexed: 02/07/2023] Open
Abstract
Early life, systemic inflammation causes long-lasting changes in behavior. To unmask possible mechanisms associated with this phenomenon, we asked whether the intrinsic membrane properties in hippocampal neurons were altered as a consequence of early life inflammation. C57BL/6 mice were bred in-house and both male and female pups from multiple litters were injected with lipopolysaccharide (LPS; 100 μg/kg, i.p.) or vehicle at postnatal day (P)14, and kept until adolescence (P35-P45) or adulthood (P60-P70), when brain slices were prepared for whole-cell and perforated-patch recordings from CA1 hippocampal pyramidal neurons. In neurons of adult male mice pretreated with LPS, the number of action potentials elicited by depolarizing current pulses was significantly increased compared with control neurons, concomitant with increased input resistance, and a lower action potential threshold. Although these changes were not associated with changes in relevant sodium channel expression or differences in capacitance or dendritic architecture, they were linked to a mechanism involving intracellular chloride overload, revealed through a depolarized GABA reversal potential and increased expression of the chloride transporter, NKCC1. In contrast, no significant changes were observed in neurons of adult female mice pretreated with LPS, nor in adolescent mice of either sex. These data uncover a potential mechanism involving neonatal inflammation-induced plasticity in chloride homeostasis, which may contribute to early life inflammation-induced behavioral alterations.SIGNIFICANCE STATEMENT Early life inflammation results in long-lasting changes in many aspects of adult physiology. In this paper we reveal that a brief exposure to early life peripheral inflammation with LPS increases excitability in hippocampal neurons in a sex- and age-dependent manner through a chloride homeostasis disruption. As this hyperexcitability was only seen in adult males, and not in adult females or adolescent animals of either sex, it raises the possibility of a hormonal interaction with early life inflammation. Furthermore, as neonatal inflammation is a normal feature of early life in most animals, as well as humans, these findings may be very important for the development of animal models of disease that more appropriately resemble the human condition.
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14
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Acetylcholine receptor agonist effect on seizure activity and GABAergic mechanisms involved in prolonged febrile seizure development in an animal model. Brain Res Bull 2019; 149:203-207. [DOI: 10.1016/j.brainresbull.2019.04.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 04/17/2019] [Accepted: 04/24/2019] [Indexed: 12/21/2022]
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15
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Lewis ML, Kesler M, Candy SA, Rho JM, Pittman QJ. Comorbid epilepsy in autism spectrum disorder: Implications of postnatal inflammation for brain excitability. Epilepsia 2018; 59:1316-1326. [PMID: 29858515 DOI: 10.1111/epi.14440] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/09/2018] [Indexed: 12/30/2022]
Abstract
OBJECTIVE In different cohorts, 5%-30% of individuals with autism spectrum disorder (ASD) also have epilepsy. The high co-occurrence of these disorders suggests that a common mechanistic link may exist. The underlying pathophysiology of this comorbidity remains unknown. To investigate the mechanism(s) involved in the pathogenesis of ASD and epilepsy, we developed and validated a novel mouse model that concurrently exhibits hallmark features of both disorders. METHODS We utilized inbred BTBR T+ Itpr3tf/J (BTBR) mice that exhibit the core behavioral characteristics of ASD (ie, impaired sociability, altered vocalizations, and restricted interests). BTBR mice received a lipopolysaccharide (LPS) or sterile saline injection at postnatal day (P)7, P14, or P21. Cytokine expression was analyzed for interleukin (IL)-1β, IL-10, IL-6, and tumor necrosis factor α in brain tissue of P7 and adult BTBR mice. Adult BTBR mice were behaviorally analyzed for seizure susceptibility, sociability, communication deficits, and motor stereotypies, and monitored using chronic video-electroencephalography (EEG). RESULTS Adult male and female BTBR mice treated at P7-P14 with LPS were more sensitive to pentylenetetrazol-induced seizures than saline-treated controls. ASD-like behaviors and hippocampal cytokine levels were unchanged between P7 LPS-treated BTBR mice and controls. EEG recordings from the dorsal hippocampus revealed a significant increase in number and frequency of seizures over the 4-week recording period (P60-P88) in BTBR mice postnatally treated with LPS at P7. These results indicate the presence of a comorbid epileptic phenotype in BTBR mice. SIGNIFICANCE These findings suggest that an early postnatal immune challenge can increase brain excitability in adult BTBR mice and reveal an underlying epilepsy phenotype. This novel animal model may enable the elucidation of specific molecular alterations that are associated with the concurrent presentation of ASD and epilepsy, which could facilitate the development of targeted therapies for individuals affected by this comorbidity.
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Affiliation(s)
- Megan Leigh Lewis
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Mitchell Kesler
- Departments of Pediatrics, Clinical Neurosciences, and Physiology and Pharmacology, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Sydney A Candy
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jong M Rho
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Departments of Pediatrics, Clinical Neurosciences, and Physiology and Pharmacology, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Quentin J Pittman
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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16
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Kasahara Y, Ikegaya Y, Koyama R. Neonatal Seizure Models to Study Epileptogenesis. Front Pharmacol 2018; 9:385. [PMID: 29720941 PMCID: PMC5915831 DOI: 10.3389/fphar.2018.00385] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 04/04/2018] [Indexed: 12/11/2022] Open
Abstract
Current therapeutic strategies for epilepsy include anti-epileptic drugs and surgical treatments that are mainly focused on the suppression of existing seizures rather than the occurrence of the first spontaneous seizure. These symptomatic treatments help a certain proportion of patients, but these strategies are not intended to clarify the cellular and molecular mechanisms underlying the primary process of epilepsy development, i.e., epileptogenesis. Epileptogenic changes include reorganization of neural and glial circuits, resulting in the formation of an epileptogenic focus. To achieve the goal of developing “anti-epileptogenic” drugs, we need to clarify the step-by-step mechanisms underlying epileptogenesis for patients whose seizures are not controllable with existing “anti-epileptic” drugs. Epileptogenesis has been studied using animal models of neonatal seizures because such models are useful for studying the latent period before the occurrence of spontaneous seizures and the lowering of the seizure threshold. Further, neonatal seizure models are generally easy to handle and can be applied for in vitro studies because cells in the neonatal brain are suitable for culture. Here, we review two animal models of neonatal seizures for studying epileptogenesis and discuss their features, specifically focusing on hypoxia-ischemia (HI)-induced seizures and febrile seizures (FSs). Studying these models will contribute to identifying the potential therapeutic targets and biomarkers of epileptogenesis.
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Affiliation(s)
- Yuka Kasahara
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Ryuta Koyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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17
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Kasahara Y, Ikegaya Y, Koyama R. [Mouse model of febrile seizures]. Nihon Yakurigaku Zasshi 2017; 150:240-245. [PMID: 29118287 DOI: 10.1254/fpj.150.240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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18
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Koepp MJ, Årstad E, Bankstahl JP, Dedeurwaerdere S, Friedman A, Potschka H, Ravizza T, Theodore WH, Baram TZ. Neuroinflammation imaging markers for epileptogenesis. Epilepsia 2017; 58 Suppl 3:11-19. [PMID: 28675560 DOI: 10.1111/epi.13778] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/06/2017] [Indexed: 12/23/2022]
Abstract
Epilepsy can be a devastating disorder. In addition to debilitating seizures, epilepsy can cause cognitive and emotional problems with reduced quality of life. Therefore, the major aim is to prevent the disorder in the first place: identify, detect, and reverse the processes responsible for its onset, and monitor and treat its progression. Epilepsy often occurs following a latent period of months to years (epileptogenesis) as a consequence of a brain insult, such as head trauma, stroke, or status epilepticus. Although this latent period clearly represents a therapeutic window, we are not able to stratify patients at risk for long-term epilepsy, which is prerequisite for preventative clinical trials. Moreover, because of the length of the latent period, an early biomarker for treatment response would be of high value. Finally, mechanistic biomarkers of epileptogenesis may provide more profound insight in the process of disease development.
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Affiliation(s)
- Matthias J Koepp
- Institute of Neurology, University College London, London, United Kingdom
| | - Eric Årstad
- Department of Chemistry and Institute of Nuclear Medicine, University College London, London, United Kingdom
| | - Jens P Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | | | - Alon Friedman
- Ben-Gurion University of the Negev, Beer-Sheva, Israel.,Dalhousie University, Halifax, Nova Scotia, Canada
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Teresa Ravizza
- Department of Neuroscience, IRCCS-Institute for Pharmacological Research Mario Negri, Milan, Italy
| | | | - Tallie Z Baram
- Departments of Pediatrics, Anatomy/Neurobiology, Neurology, University of California-Irvine, Irvine, California, U.S.A
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19
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Lameth J, Gervais A, Colin C, Lévêque P, Jay TM, Edeline JM, Mallat M. Acute Neuroinflammation Promotes Cell Responses to 1800 MHz GSM Electromagnetic Fields in the Rat Cerebral Cortex. Neurotox Res 2017; 32:444-459. [PMID: 28578480 DOI: 10.1007/s12640-017-9756-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/16/2017] [Accepted: 05/19/2017] [Indexed: 01/08/2023]
Abstract
Mobile phone communications are conveyed by radiofrequency (RF) electromagnetic fields, including pulse-modulated global system for mobile communications (GSM)-1800 MHz, whose effects on the CNS affected by pathological states remain to be specified. Here, we investigated whether a 2-h head-only exposure to GSM-1800 MHz could impact on a neuroinflammatory reaction triggered by lipopolysaccharide (LPS) in 2-week-old or adult rats. We focused on the cerebral cortex in which the specific absorption rate (SAR) of RF averaged 2.9 W/kg. In developing rats, 24 h after GSM exposure, the levels of cortical interleukin-1ß (IL1ß) or NOX2 NADPH oxidase transcripts were reduced by 50 to 60%, in comparison with sham-exposed animals (SAR = 0), as assessed by RT-qPCR. Adult rats exposed to GSM also showed a 50% reduction in the level of IL1ß mRNA, but they differed from developing rats by the lack of NOX2 gene suppression and by displaying a significant growth response of microglial cell processes imaged in anti-Iba1-stained cortical sections. As neuroinflammation is often associated with changes in excitatory neurotransmission, we evaluated changes in expression and phosphorylation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in the adult cerebral cortex by Western blot analyses. We found that GSM exposure decreased phosphorylation at two residues on the GluA1 AMPAR subunit (serine 831 and 845). The GSM-induced changes in gene expressions, microglia, and GluA1 phosphorylation did not persist 72 h after RF exposure and were not observed in the absence of LPS pretreatment. Together, our data provide evidence that GSM-1800 MHz can modulate CNS cell responses triggered by an acute neuroinflammatory state.
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Affiliation(s)
- Julie Lameth
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France
| | - Annie Gervais
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France
| | - Catherine Colin
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France
| | - Philippe Lévêque
- Université de Limoges, CNRS, XLIM, UMR 7252, 123 avenue Albert Thomas, F-87000, Limoges, France
| | - Thérèse M Jay
- Physiopathologie des Maladies Psychiatriques, Centre de Psychiatrie et Neurosciences, UMR_S894 INSERM, Université Paris Descartes, 102-108 rue de la Santé, 75014, Paris, France
| | - Jean-Marc Edeline
- Paris Saclay Institute of Neuroscience, Neuro-PSI, UMR 9197 CNRS, Université Paris-Sud, 91405, Orsay cedex, France
| | - Michel Mallat
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U.1127, CNRS, Institut du Cerveau et de la Moelle épinière (ICM), Hôpital Pitié-Salpêtrière, Bat. ICM, 47 boulevard de l'Hôpital, F-75013, Paris, France.
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20
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Peña-Ortega F. Pharmacological Tools to Activate Microglia and their Possible use to Study Neural Network Patho-physiology. Curr Neuropharmacol 2017; 15:595-619. [PMID: 27697040 PMCID: PMC5543677 DOI: 10.2174/1570159x14666160928151546] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 08/05/2016] [Accepted: 09/26/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Microglia are the resident immunocompetent cells of the CNS and also constitute a unique cell type that contributes to neural network homeostasis and function. Understanding microglia cell-signaling not only will reveal their diverse functions but also will help to identify pharmacological and non-pharmacological tools to modulate the activity of these cells. METHODS We undertook a search of bibliographic databases for peer-reviewed research literature to identify microglial activators and their cell-specificity. We also looked for their effects on neural network function and dysfunction. RESULTS We identified several pharmacological targets to modulate microglial function, which are more or less specific (with the proper control experiments). We also identified pharmacological targets that would require the development of new potent and specific modulators. We identified a wealth of evidence about the participation of microglia in neural network function and their alterations in pathological conditions. CONCLUSION The identification of specific microglia-activating signals provides experimental tools to modulate the activity of this heterogeneous cell type in order to evaluate its impact on other components of the nervous system, and it also helps to identify therapeutic approaches to ease some pathological conditions related to microglial dysfunction.
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Affiliation(s)
- Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, UNAM-Campus Juriquilla, México
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21
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Doenni VM, Gray JM, Song CM, Patel S, Hill MN, Pittman QJ. Deficient adolescent social behavior following early-life inflammation is ameliorated by augmentation of anandamide signaling. Brain Behav Immun 2016; 58:237-247. [PMID: 27453335 PMCID: PMC5461973 DOI: 10.1016/j.bbi.2016.07.152] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 07/15/2016] [Accepted: 07/20/2016] [Indexed: 11/18/2022] Open
Abstract
Early-life inflammation has been shown to exert profound effects on brain development and behavior, including altered emotional behavior, stress responsivity and neurochemical/neuropeptide receptor expression and function. The current study extends this research by examining the impact of inflammation, triggered with the bacterial compound lipopolysaccharide (LPS) on postnatal day (P) 14, on social behavior during adolescence. We investigated the role that the endocannabinoid (eCB) system plays in sociability after early-life LPS. To test this, multiple cohorts of Sprague Dawley rats were injected with LPS on P14. In adolescence, rats were subjected to behavioral testing in a reciprocal social interaction paradigm as well as the open field. We quantified eCB levels in the amygdala of P14 and adolescent animals (anandamide and 2-arachidonoylglycerol) as well as adolescent amygdaloid cannabinoid receptor 1 (CB1) binding site density and the hydrolytic activity of the enzyme fatty acid amide hydrolase (FAAH), which metabolizes the eCB anandamide. Additionally, we examined the impact of FAAH inhibition on alterations in social behavior. Our results indicate that P14 LPS decreases adolescent social behavior (play and social non-play) in males and females at P40. This behavioral alteration is accompanied by decreased CB1 binding, increased anandamide levels and increased FAAH activity. Oral administration of the FAAH inhibitor PF-04457845 (1mg/kg) prior to the social interaction task normalizes LPS-induced alterations in social behavior, while not affecting social behavior in the control group. Infusion of 10ng PF-04457845 into the basolateral amygdala normalized social behavior in LPS injected females. These data suggest that alterations in eCB signaling following postnatal inflammation contribute to impairments in social behavior during adolescence and that inhibition of FAAH could be a novel target for disorders involving social deficits such as social anxiety disorders or autism.
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Affiliation(s)
- V M Doenni
- Hotchkiss Brain Institute, Cumming School of Medicine, Mathison Center for Mental Health, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada; Department of Neuroscience, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada.
| | - J M Gray
- Hotchkiss Brain Institute, Cumming School of Medicine, Mathison Center for Mental Health, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
| | - C M Song
- Hotchkiss Brain Institute, Cumming School of Medicine, Mathison Center for Mental Health, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
| | - S Patel
- Department of Psychiatry, Vanderbilt School of Medicine, Vanderbilt Brain Institute, Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, 1211 Medical Center Dr, Nashville, TN 37232, United States
| | - M N Hill
- Hotchkiss Brain Institute, Cumming School of Medicine, Mathison Center for Mental Health, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
| | - Q J Pittman
- Hotchkiss Brain Institute, Cumming School of Medicine, Mathison Center for Mental Health, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
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22
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McDonald FB, Chandrasekharan K, Wilson RJA, Hasan SU. Interactive effects of maternal cigarette smoke, heat stress, hypoxia, and lipopolysaccharide on neonatal cardiorespiratory and cytokine responses. Am J Physiol Regul Integr Comp Physiol 2016; 311:R1113-R1124. [PMID: 27733384 DOI: 10.1152/ajpregu.00062.2016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 10/03/2016] [Accepted: 10/06/2016] [Indexed: 11/22/2022]
Abstract
Maternal cigarette smoke (CS) exposure exhibits a strong epidemiological association with Sudden Infant Death Syndrome, but other environmental stressors, including infection, hyperthermia, and hypoxia, have also been postulated as important risk factors. This study examines whether maternal CS exposure causes maladaptations within homeostatic control networks by influencing the response to lipopolysaccharide, heat stress, and/or hypoxia in neonatal rats. Pregnant dams were exposed to CS or parallel sham treatments daily for the length of gestation. Offspring were studied at postnatal days 6-8 at ambient temperatures (Ta) of 33°C or 38°C. Within each group, rats were allocated to control, saline, or LPS (200 µg/kg) treatments. Cardiorespiratory patterns were examined using head-out plethysmography and ECG surface electrodes during normoxia and hypoxia (10% O2). Serum cytokine concentrations were quantified from samples taken at the end of each experiment. Our results suggest maternal CS exposure does not alter minute ventilation (V̇e) or heart rate (HR) response to infection or high temperature, but independently increases apnea frequency. CS also primes the inflammatory system to elicit a stronger cytokine response to bacterial insult. High Ta independently depresses V̇e but augments the hypoxia-induced increase in V̇e Moreover, higher Ta increases HR during normoxia and hypoxia, and in the presence of an immune challenge, increases HR during normoxia, and reduces the increase normally associated with hypoxia. Thus, while most environmental risk factors increase the burden on the cardiorespiratory system in early life, hyperthermia and infection blunt the normal HR response to hypoxia, and gestational CS independently destabilizes breathing by increasing apneas.
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Affiliation(s)
- Fiona B McDonald
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Faculty of Medicine, University of Calgary, Alberta, Canada; and
| | - Kumaran Chandrasekharan
- Section of Neonatal-Perinatal Medicine, Department of Pediatrics, Faculty of Medicine, Health Sciences Centre, University of Calgary, Alberta, Canada
| | - Richard J A Wilson
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Faculty of Medicine, University of Calgary, Alberta, Canada; and
| | - Shabih U Hasan
- Section of Neonatal-Perinatal Medicine, Department of Pediatrics, Faculty of Medicine, Health Sciences Centre, University of Calgary, Alberta, Canada
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23
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McDonald FB, Chandrasekharan K, Wilson RJA, Hasan SU. Cardiorespiratory control and cytokine profile in response to heat stress, hypoxia, and lipopolysaccharide (LPS) exposure during early neonatal period. Physiol Rep 2016; 4:4/2/e12688. [PMID: 26811056 PMCID: PMC4760388 DOI: 10.14814/phy2.12688] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Sudden infant death syndrome (SIDS) is one of the most common causes of postneonatal infant mortality in the developed world. An insufficient cardiorespiratory response to multiple environmental stressors (such as prone sleeping positioning, overwrapping, and infection), during a critical period of development in a vulnerable infant, may result in SIDS. However, the effect of multiple risk factors on cardiorespiratory responses has rarely been tested experimentally. Therefore, this study aimed to quantify the independent and possible interactive effects of infection, hyperthermia, and hypoxia on cardiorespiratory control in rats during the neonatal period. We hypothesized that lipopolysaccharide (LPS) administration will negatively impact cardiorespiratory responses to increased ambient temperature and hypoxia in neonatal rats. Sprague-Dawley neonatal rat pups were studied at postnatal day 6-8. Rats were examined at an ambient temperature of 33°C or 38°C. Within each group, rats were allocated to control, saline, or LPS (200 μg/kg) treatments. Cardiorespiratory and thermal responses were recorded and analyzed before, during, and after a hypoxic exposure (10% O2). Serum samples were taken at the end of each experiment to measure cytokine concentrations. LPS significantly increased cytokine concentrations (such as TNFα, IL-1β, MCP-1, and IL-10) compared to control. Our results do not support a three-way interaction between experimental factors on cardiorespiratory control. However, independently, heat stress decreased minute ventilation during normoxia and increased the hypoxic ventilatory response. Furthermore, LPS decreased hypoxia-induced tachycardia. Herein, we provide an extensive serum cytokine profile under various experimental conditions and new evidence that neonatal cardiorespiratory responses are adversely affected by dual interactions of environmental stress factors.
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Affiliation(s)
- Fiona B McDonald
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute & Alberta Children's Hospital Research Institute, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Kumaran Chandrasekharan
- Fetal and Neonatal Physiology, Department of Pediatrics, Faculty of Medicine B271, Health Sciences Center, University of Calgary, Calgary, Alberta, Canada
| | - Richard J A Wilson
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute & Alberta Children's Hospital Research Institute, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Shabih U Hasan
- Fetal and Neonatal Physiology, Department of Pediatrics, Faculty of Medicine B271, Health Sciences Center, University of Calgary, Calgary, Alberta, Canada
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Feng B, Chen Z. Generation of Febrile Seizures and Subsequent Epileptogenesis. Neurosci Bull 2016; 32:481-92. [PMID: 27562688 DOI: 10.1007/s12264-016-0054-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/13/2016] [Indexed: 11/24/2022] Open
Abstract
Febrile seizures (FSs) occur commonly in children aged from 6 months to 5 years. Complex (repetitive or prolonged) FSs, but not simple FSs, can lead to permanent brain modification. Human infants and immature rodents that have experienced complex FSs have a high risk of subsequent temporal lobe epilepsy. However, the causes of FSs and the mechanisms underlying the subsequent epileptogenesis remain unknown. Here, we mainly focus on two major questions concerning FSs: how fever triggers seizures, and how epileptogenesis occurs after FSs. The risk factors responsible for the occurrence of FSs and the epileptogenesis after prolonged FSs are thoroughly summarized and discussed. An understanding of these factors can provide potential therapeutic targets for the prevention of FSs and also yield biomarkers for identifying patients at risk of epileptogenesis following FSs.
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Affiliation(s)
- Bo Feng
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Zhong Chen
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, Hangzhou, 310058, China.
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25
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Rapid, Coordinate Inflammatory Responses after Experimental Febrile Status Epilepticus: Implications for Epileptogenesis. eNeuro 2015; 2:eN-NWR-0034-15. [PMID: 26730400 PMCID: PMC4699830 DOI: 10.1523/eneuro.0034-15.2015] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 09/25/2015] [Accepted: 09/28/2015] [Indexed: 11/29/2022] Open
Abstract
Epilepsy is a common neurological disorder with many causes. For temporal lobe epilepsy, antecedent insults are typically found. These risk factors include trauma or history of long fever-associated seizures (febrile status epilepticus) in childhood. Whereas the mechanisms by which such insults promote temporal lobe epilepsy are unknown, an extensive body of work has implicated inflammation and inflammatory mediators in both human and animal models of the disorder. However, direct evidence for an epileptogenic role for inflammation is lacking. Here we capitalized on a model where only a subgroup of insult-experiencing rodents develops epilepsy. We reasoned that if inflammation was important for generating epilepsy, then early inflammation should be more prominent in individuals destined to become epileptic compared with those that will not become epileptic. In addition, the molecular and temporal profile of inflammatory mediators would provide insights into which inflammatory pathways might be involved in the disease process. We examined inflammatory profiles in hippocampus and amygdala of individual rats and correlated them with a concurrent noninvasive, amygdalar magnetic resonance imaging epilepsy-predictive marker. We found significant individual variability in the expression of several important inflammatory mediators, but not in others. Of interest, a higher expression of a subset of hippocampal and amygdalar inflammatory markers within the first few hours following an insult correlated with the epilepsy-predictive signal. These findings suggest that some components of the inflammatory gene network might contribute to the process by which insults promote the development of temporal lobe epilepsy.
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26
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Cassim S, Qulu L, Mabandla MV. Prenatal stress and early life febrile convulsions compromise hippocampal genes MeCP2/REST function in mid-adolescent life of Sprague-Dawley rats. Neurobiol Learn Mem 2015; 125:195-201. [DOI: 10.1016/j.nlm.2015.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/06/2015] [Accepted: 09/01/2015] [Indexed: 02/08/2023]
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Exposure to prenatal stress has deleterious effects on hippocampal function in a febrile seizure rat model. Brain Res 2015; 1624:506-514. [DOI: 10.1016/j.brainres.2015.07.040] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 06/29/2015] [Accepted: 07/23/2015] [Indexed: 12/21/2022]
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28
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Qulu L, Daniels WMU, Russell V, Mabandla MV. Searsia chirindensis reverses the potentiating effect of prenatal stress on the development of febrile seizures and decreased plasma interleukin-1β levels. Neurosci Res 2015; 103:54-8. [PMID: 26320878 DOI: 10.1016/j.neures.2015.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/18/2015] [Accepted: 08/21/2015] [Indexed: 12/16/2022]
Abstract
It is estimated that more than 80% of patients with epilepsy live in developing countries with 50-60% of them being children. This high prevalence is perpetuated by low socio-economic challenges, poor health care facilities and lack of drug affordability. Searsia chirindensis formerly known as rhus chirindensis and commonly known as 'Red Current' is a popular traditional medicinal plant, which has been used to treat a number of illnesses such as heart complaints and neurological disorders. The aim of this study is to investigate the effects of S. chirindensis on the development of febrile seizure in a prenatally stressed rat. Febrile seizures were induced by administering lipopolysaccharide to 14-day-old rat pups followed by kainic acid. A subset of the rats was treated with Searsia after induction of febrile seizures. Interleukin-1β (IL-1β) levels were measured in plasma. Lipid peroxidation was determined in liver tissue. Our data shows that treatment with Searsia reduced interleukin-1β levels in plasma of the febrile seizure rats and prevented lipid oxidation in the liver. Prenatal stress is dampened by the beneficial effects of Searsia on seizure development in rat pups. These results highlight the potentiating effects of Searsia in the reversal of febrile seizures and prenatal stress effects.
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Affiliation(s)
- Lihle Qulu
- Department of Human Physiology, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Willie M U Daniels
- Department of Human Physiology, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Vivienne Russell
- Department of Human Physiology, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Musa V Mabandla
- Department of Human Physiology, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa.
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29
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Suchomelova L, Lopez-Meraz ML, Niquet J, Kubova H, Wasterlain CG. Hyperthermia aggravates status epilepticus-induced epileptogenesis and neuronal loss in immature rats. Neuroscience 2015; 305:209-24. [PMID: 26259902 DOI: 10.1016/j.neuroscience.2015.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 07/20/2015] [Accepted: 08/03/2015] [Indexed: 01/16/2023]
Abstract
This study tightly controlled seizure duration and severity during status epilepticus (SE) in postnatal day 10 (P10) rats, in order to isolate hyperthermia as the main variable and to study its consequences. Body temperature was maintained at 39 ± 1 °C in hyperthermic SE rats (HT+SE) or at 35 ± 1 °C in normothermic SE animals (NT+SE) during 30 min of SE, which was induced by lithium-pilocarpine (3 mEq/kg, 60 mg/kg) and terminated by diazepam and cooling to NT. All video/EEG measures of SE severity were similar between HT+SE and NT+SE pups. At 24h, neuronal injury was present in the amygdala in the HT+SE group only, and was far more severe in the hippocampus in HT+SE than NT+SE pups. Separate groups of animals were monitored four months later for spontaneous recurrent seizures (SRS). Only HT+SE animals developed convulsive SRS. Both HT+SE and NT+SE animals developed electrographic SRS (83% vs. 55%), but SRS frequency and severity were higher in hyperthermic animals (12.5 ± 3.5 vs. 4.2 ± 2.0 SRS/day). The density of hilar neurons was lower, thickness of the amygdala and perirhinal cortex was reduced, and lateral ventricles were enlarged in HT+SE over NT+SE littermates and HT/NT controls. In this model, hyperthermia greatly increased the epileptogenicity of SE and its neuropathological sequelae.
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Affiliation(s)
- L Suchomelova
- Veterans Administration Greater Los Angeles Healthcare System, Epilepsy Research (151), 11 301 Wilshire Boulevard, Building 114, Room 139, Los Angeles, CA 90073, USA.
| | - M L Lopez-Meraz
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Veracruz 91190, Mexico
| | - J Niquet
- Veterans Administration Greater Los Angeles Healthcare System, Epilepsy Research (151), 11 301 Wilshire Boulevard, Building 114, Room 139, Los Angeles, CA 90073, USA
| | - H Kubova
- Department of Developmental Epileptology, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 14220, Czech Republic
| | - C G Wasterlain
- Department of Neurology, David Geffen School of Medicine at UCLA, VA Medical Center (127), 11 301 Wilshire Boulevard, Los Angeles, CA 90073, USA
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Eun BL, Abraham J, Mlsna L, Kim MJ, Koh S. Lipopolysaccharide potentiates hyperthermia-induced seizures. Brain Behav 2015; 5:e00348. [PMID: 26357586 PMCID: PMC4559014 DOI: 10.1002/brb3.348] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 03/25/2015] [Accepted: 04/05/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Prolonged febrile seizures (FS) have both acute and long-lasting effects on the developing brain. Because FS are often associated with peripheral infection, we aimed to develop a preclinical model of FS that simulates fever and immune activation in order to facilitate the implementation of targeted therapy after prolonged FS in young children. METHODS The innate immune activator lipopolysaccharide (LPS) was administered to postnatal day 14 rat (200 μg/kg) and mouse (100 μg/kg) pups 2-2.5 h prior to hyperthermic seizures (HT) induced by hair dryer or heat lamp. To determine whether simulation of infection enhances neuronal excitability, latency to seizure onset, threshold temperature and total number of seizures were quantified. Behavioral seizures were correlated with electroencephalographic changes in rat pups. Seizure-induced proinflammatory cytokine production was assessed in blood samples at various time points after HT. Seizure-induced microglia activation in the hippocampus was quantified using Cx3cr1(GFP/+) mice. RESULTS Lipopolysaccharide priming increased susceptibility of rats and mice to hyperthemic seizures and enhanced seizure-induced proinflammatory cytokine production and microglial activation. CONCLUSIONS Peripheral inflammation appears to work synergistically with hyperthermia to potentiate seizures and to exacerbate seizure-induced immune responses. By simulating fever, a regulated increase in body temperature from an immune challenge, we developed a more clinically relevant animal model of prolonged FS.
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Affiliation(s)
- Baik-Lin Eun
- Department of Pediatrics, Korea University College of Medicine Seoul, Korea
| | - Jayne Abraham
- Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital of Chicago Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, Illinois
| | - Lauren Mlsna
- Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital of Chicago Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, Illinois
| | - Min Jung Kim
- Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital of Chicago Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, Illinois
| | - Sookyong Koh
- Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital of Chicago Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, Illinois
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31
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Zare-Shahabadi A, Ashrafi MR, Shahrokhi A, Soltani S, Zoghi S, Soleimani F, Vameghi R, Badv RS, Rezaei N. Single nucleotide polymorphisms of TNF-Α gene in febrile seizures. J Neurol Sci 2015; 356:153-6. [PMID: 26119396 DOI: 10.1016/j.jns.2015.06.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 06/20/2015] [Accepted: 06/22/2015] [Indexed: 11/17/2022]
Abstract
Febrile seizures (FS) is the most common seizure disorder during childhood. This study was performed in 78 patients with FS and 137 control subjects to assess polymorphisms of the TNF-α gene at positions -308 and -238, using the polymerase chain reaction and the sequence specific primers method. The highest positive allelic association that made the patients susceptible to FS was seen for TNF-α -238/G (p<0.0001). The GG genotype at TNF-α -238 was significantly higher in the patients with FS, compared to the controls (p=0.0001). Also, GA genotype at the same position was significantly lower in patients than in controls (P=0.0001). The GG haplotype had a significant positive association at TNF-α (308, 238) while GA haplotype showed a negative association (P<0.001). Our data support the idea that TNF-α single-nucleotide polymorphisms play a role in the pathogenesis of FS.
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Affiliation(s)
- Ameneh Zare-Shahabadi
- Molecular Immunology Research Center and Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Mahmoud Reza Ashrafi
- Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Amin Shahrokhi
- Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran; Pediatric Neurorehabilitation Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Samaneh Soltani
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Samaneh Zoghi
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Farin Soleimani
- Pediatric Neurorehabilitation Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Roshanak Vameghi
- Pediatric Neurorehabilitation Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Reza Shervin Badv
- Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Nima Rezaei
- Molecular Immunology Research Center and Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran; Universal Scientific Education and Research Network (USERN), Tehran, Iran.
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32
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Korgan AC, Vonkeman J, Esser MJ, Perrot TS. An enhanced home cage modulates hypothalamic CRH-ir Labeling in juvenile rats, with and without sub-threshold febrile convulsions. Dev Psychobiol 2015; 57:374-81. [DOI: 10.1002/dev.21300] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 02/07/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Austin C. Korgan
- Department of Psychology and Neuroscience; Dalhousie University; Halifax Nova Scotia Canada
| | - Janeske Vonkeman
- Department of Psychology and Neuroscience; Dalhousie University; Halifax Nova Scotia Canada
| | - Michael J. Esser
- Department of Psychology and Neuroscience; Dalhousie University; Halifax Nova Scotia Canada
- Departments of Pediatrics and Pharmacology; IWK Health Care Center; Halifax Nova Scotia Canada
| | - Tara S. Perrot
- Department of Psychology and Neuroscience; Dalhousie University; Halifax Nova Scotia Canada
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33
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Dupuis N, Auvin S. Inflammation and epilepsy in the developing brain: clinical and experimental evidence. CNS Neurosci Ther 2014; 21:141-51. [PMID: 25604829 DOI: 10.1111/cns.12371] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 11/25/2014] [Accepted: 11/28/2014] [Indexed: 12/12/2022] Open
Abstract
There is an increasing evidence to support a role of inflammatory processes in epilepsy. However, most clinical and experimental studies have been conducted in adult patients or using adult rodents. The pediatric epilepsies constitute a varied group of diseases that are most frequently age specific. In this review, we will focus on the possible role of inflammation in pediatric epilepsy syndromes. We will first describe the clinical data available and provide an overview of our current understanding of the role of inflammation in these clinical situations. We will then review experimental data regarding the role of inflammation in epilepsy in the developing brain. To summarize, inflammation contributes to seizure precipitation, and reciprocally, prolonged seizures induce inflammation. There is also a relationship between inflammation and cell injury following status epilepticus, which differs according to the developmental stage. Finally, inflammation seems to contribute to epileptogenesis even in the developing brain. Based on the available data, we highlight the need for further studies dissecting the exact role of inflammation in epilepsy during development.
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Affiliation(s)
- Nina Dupuis
- INSERM U1141, Paris, France; APHP, Hôpital Robert Debré, Service de Neurologie Pédiatrique, DHU Protect, Paris, France; Univ Paris Diderot, Sorbonne Paris Cité, Paris, France
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34
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Gómez CD, Buijs RM, Sitges M. The anti-seizure drugs vinpocetine and carbamazepine, but not valproic acid, reduce inflammatory IL-1β and TNF-α expression in rat hippocampus. J Neurochem 2014; 130:770-9. [PMID: 24903676 DOI: 10.1111/jnc.12784] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 05/26/2014] [Accepted: 05/30/2014] [Indexed: 12/25/2022]
Abstract
In the present study, the effects of the two classical anti-epileptic drugs, carbamazepine and valproic acid, and the non-classical anti-seizure drug vinpocetine were investigated on the expression of the pro-inflammatory cytokines IL-1β and TNF-α in the hippocampus of rats by PCR or western blot after the administration of one or seven doses. Next, the effects of the anti-seizure drugs were investigated on the rise in cytokine expression induced by lipopolysaccharides (LPS) inoculation in vivo. To validate our methods, the changes induced by the pro-convulsive agents 4-aminopyridine, pentylenetetrazole and pilocarpine were also tested. Finally, the effect of the anti-seizure drugs on seizures and on the concomitant rise in pro-inflammatory cytokine expression induced by 4-aminopyridine was explored. Results show that vinpocetine and carbamazepine reduced the expression of IL-1β and TNF-α from basal conditions, and the increase in both pro-inflammatory cytokines induced by LPS. In contrast, valproic acid failed to reduce both the expression of the cytokines from basal conditions and the rise in IL-1β and TNF-α expression induced by LPS. Tonic-clonic seizures induced either by 4-aminopyridine, pentylenetetrazole or pilocarpine increased the expression of IL-1β and TNF-α markedly. 4-aminopyridine-induced changes were reduced by all the tested anti-seizure drugs, although valproic acid was less effective. We conclude that the anti-seizure drugs, vinpocetine and carbamazepine, whose mechanisms of action involve a decrease in ion channels permeability, also reduce cerebral inflammation. The mechanism of action of anti-seizure drugs like vinpocetine and carbamazepine involves a decrease in Na(+) channels permeability. We here propose that this mechanism of action also involves a decrease in cerebral inflammation.
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Affiliation(s)
- Carlos D Gómez
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, DF, México
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35
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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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36
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Korgan AC, Green AD, Perrot TS, Esser MJ. Limbic system activation is affected by prenatal predator exposure and postnatal environmental enrichment and further moderated by dam and sex. Behav Brain Res 2013; 259:106-18. [PMID: 24185030 DOI: 10.1016/j.bbr.2013.10.037] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/18/2013] [Accepted: 10/24/2013] [Indexed: 02/07/2023]
Abstract
Epilepsy is a relatively common and chronic neurological condition, affecting 1-2% of the population. However, understanding of the underlying pathophysiology remains incomplete. To identify potential factors in the early environment that may increase the risk for experiencing seizures, maternal stress and environmental enrichment (EE) were utilized. Pregnant Long-Evans rats were exposed to an ethologically relevant predator stress (PS) and maternal glucocorticoid (GC) response was assessed across the exposure period. At birth, litters were divided into standard care (SC) and EE groups until postnatal day 14 (PD14) when a model of febrile convulsions was used to determine seizure susceptibility of the various groups. Pup brains were then processed for immunohistochemical detection of FosB from several structures in the limbic system as a measure of neuronal activation. Maternal PS-induced GC levels were elevated early in the exposure period, and pup birth weights, in both sexes, were lower in litters from dams exposed to PS. Seizure scores at PD14 were highly individualized and litter dependent, suggesting a dam-dependent and variable effect of controlled pre- and postnatal environmental factors. Further, analysis of FosB-immunoreactive (-ir) patterns revealed an activity dependent distribution, reflecting individual seizure susceptibility. EE had a varying effect on FosB-ir that was dependent on region. In the hippocampus FosB-ir levels were greater in the EE groups while extra-hippocampal regions showed lower levels of FosB-ir. Our results support the concept that pre- and postnatal environmental influences affect fetal programming and neurodevelopment of processes that could underlie seizure susceptibility, but that the magnitude of these effects appears to be dam- or litter-dependent.
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Affiliation(s)
- Austin C Korgan
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Amanda D Green
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Tara S Perrot
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada.
| | - Michael J Esser
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada; Departments of Pediatrics and Pharmacology, IWK Health Care Centre, Halifax, NS, Canada
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37
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Vezzani A, Friedman A, Dingledine RJ. The role of inflammation in epileptogenesis. Neuropharmacology 2013; 69:16-24. [PMID: 22521336 PMCID: PMC3447120 DOI: 10.1016/j.neuropharm.2012.04.004] [Citation(s) in RCA: 354] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 03/19/2012] [Accepted: 04/02/2012] [Indexed: 12/20/2022]
Abstract
One compelling challenge in the therapy of epilepsy is to develop anti-epileptogenic drugs with an impact on the disease progression. The search for novel targets has focused recently on brain inflammation since this phenomenon appears to be an integral part of the diseased hyperexcitable brain tissue from which spontaneous and recurrent seizures originate. Although the contribution of specific proinflammatory pathways to the mechanism of ictogenesis in epileptic tissue has been demonstrated in experimental models, the role of these pathways in epileptogenesis is still under evaluation. We review the evidence conceptually supporting the involvement of brain inflammation and the associated blood-brain barrier damage in epileptogenesis, and describe the available pharmacological evidence where post-injury intervention with anti-inflammatory drugs has been attempted. Our review will focus on three main inflammatory pathways, namely the IL-1 receptor/Toll-like receptor signaling, COX-2 and the TGF-β signaling. The mechanisms underlying neuronal-glia network dysfunctions induced by brain inflammation are also discussed, highlighting novel neuromodulatory effects of classical inflammatory mediators such as cytokines and prostaglandins. The increase in knowledge about a role of inflammation in disease progression, may prompt the use of specific anti-inflammatory drugs for developing disease-modifying treatments. This article is part of the Special Issue entitled 'New Targets and Approaches to the Treatment of Epilepsy'.
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Affiliation(s)
- Annamaria Vezzani
- Laboratory Experimental Neurology, Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Via G. La Masa 19, 20156 Milano, Italy.
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Reid AY, Riazi K, Campbell Teskey G, Pittman QJ. Increased excitability and molecular changes in adult rats after a febrile seizure. Epilepsia 2013; 54:e45-8. [DOI: 10.1111/epi.12061] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2012] [Indexed: 12/31/2022]
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Chen YH, Kuo TT, Chu MT, Ma HI, Chiang YH, Huang EYK. Postnatal systemic inflammation exacerbates impairment of hippocampal synaptic plasticity in an animal seizure model. Neuroimmunomodulation 2013; 20:223-32. [PMID: 23736043 DOI: 10.1159/000348440] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 01/25/2013] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE To investigate the effects of systemic inflammation in the critical postnatal stages on neurophysiological actions of immune processes and neural plasticity in adult rats after kainic acid (KA)-induced seizures. METHODS To determine changes in hippocampal synaptic plasticity after postnatal central nervous system inflammatory responses and seizure attacks, we performed intraperitoneal injections of lipopolysaccharide (LPS) in postnatal Sprague Dawley rats on day 14 (P14) to induce central nervous system inflammation. We then used a KA tail vein injection on P35 to induce seizure attacks. We compared the variability in synaptic plasticity in the hippocampal Schaffer collateral-CA1 region of seizure animals with or without LPS-induced inflammation preconditioning. RESULTS P14 injection of LPS increased susceptibility to seizures, while treatment with KA on P35 induced seizures. Long-term potentiation (LTP) of the Schaffer collateral-CA1 region was impaired in seizure animals, and this effect was more pronounced in the P14 LPS injection group. Fluoro-Jade staining revealed an increase in degenerated hippocampal CA1 pyramidal cells in the P14 LPS injection group. Cytokine expression in the hippocampus in the pre-, peri- and postictus periods was greater in P14 LPS rats than in saline-treated rats. CONCLUSIONS Intraperitoneal LPS injection on P14 induces higher cytokine secretion after KA-induced seizures, enhancing neuronal excitability, shortening seizure onset time and exacerbating neuronal degeneration and impairment of LTP formation in the hippocampal Schaffer collateral-CA1 region. Central nervous system inflammation during critical stages of childhood development could disrupt the balance needed for neurophysiological actions of immune processes, producing direct, pernicious effects on memory, neural plasticity and neurogenesis into adulthood.
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Affiliation(s)
- Yuan-Hao Chen
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC
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Qulu L, Daniels WMU, Mabandla MV. Exposure to prenatal stress enhances the development of seizures in young rats. Metab Brain Dis 2012; 27:399-404. [PMID: 22527993 DOI: 10.1007/s11011-012-9300-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 03/22/2012] [Indexed: 11/29/2022]
Abstract
A febrile seizure is a neurological disorder that occurs following an infection that results in a rapid rise in body temperature. It commonly affects 3-5% of children between the ages of 3 months and 5 years. Interleukin-1 beta IL-1β a pro-inflammatory cytokine has been suggested to play a role in the manifestation of febrile seizures. There is evidence suggesting that neurological disorders can be exacerbated in an offspring that was exposed to stress prenatally. The aim of our study was therefore to investigate whether febrile seizures are exacerbated in the offspring of rats that were prenatally stressed. The offspring of pregnant Sprague-Dawley dams were used in the study. Prenatal stress consisted of exposing the pregnant dams to 45 min of restraint, 3 times per day with 3 h intervals in-between, for 7 days starting on gestational day 14 (GND14). On postnatal day (PND) 14, the pups were injected with lipopolysaccharide (LPS, 200 μg/kg, i.p.) followed 2.5 h later by an i.p. injection of kainic acid (KA, 1.75 mg/kg). All the animals were decapitated on PND 21. Trunk blood was collected to detect plasma interleukin-1beta (IL-1β) levels in the various groups. Our data showed that i.p. injections of LPS followed by KA led to the development of seizure activity that was associated with increased plasma IL-1β levels. Prior exposure to prenatal stress resulted in the development of advanced stages of seizure development, leading to an exaggerated seizure response. Prenatal stress alone also led to elevated plasma IL-1β levels, while previously stressed animals receiving LPS and KA yielded the highest plasma levels of IL-1β levels. Our data therefore shows that IL-1β levels may play an important role in the development of febrile seizures.
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MESH Headings
- Animals
- Animals, Newborn
- Disease Models, Animal
- Female
- Male
- Pregnancy
- Prenatal Exposure Delayed Effects/metabolism
- Prenatal Exposure Delayed Effects/physiopathology
- Rats
- Rats, Sprague-Dawley
- Restraint, Physical
- Seizures, Febrile/chemically induced
- Seizures, Febrile/complications
- Seizures, Febrile/physiopathology
- Stress, Psychological/blood
- Stress, Psychological/complications
- Stress, Psychological/physiopathology
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Affiliation(s)
- Lihle Qulu
- Department of Human Physiology, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa
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Abstract
Although long granted the status of immune privilege, the central nervous system is not completely isolated from the immune system. Increasing evidence suggests that this system contributes to seizures and epilepsy and that the molecular mediators of inflammation and immunity may serve as appropriate targets in the quest to develop novel antiepileptic drugs that are more efficacious and potentially disease modifying.
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Atypical febrile seizures, mesial temporal lobe epilepsy, and dual pathology. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:342928. [PMID: 22957226 PMCID: PMC3420631 DOI: 10.1155/2012/342928] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2011] [Revised: 02/02/2012] [Accepted: 02/07/2012] [Indexed: 12/02/2022]
Abstract
Febrile seizures occurring in the neonatal period, especially when prolonged, are thought to be involved in the later development of mesial temporal lobe epilepsy (mTLE) in children. The presence of an often undetected, underlying cortical malformation has also been reported to be implicated in the epileptogenesis process following febrile seizures. This paper highlights some of the various animal models of febrile seizures and of cortical malformation and portrays a two-hit model that efficiently mimics these two insults and leads to spontaneous recurrent seizures in adult rats. Potential mechanisms are further proposed to explain how these two insults may each, or together, contribute to network hyperexcitability and epileptogenesis. Finally the clinical relevance of the two-hit model is briefly discussed in light of a therapeutic and preventive approach to mTLE.
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Akarsu ES, Mamuk S. Seizure susceptibility and electroencephalogram power spectra alterations at various phases of the lipopolysaccharide-induced hypothermic response in biotelemetered rats. Epilepsy Res 2012; 100:20-6. [PMID: 22269424 DOI: 10.1016/j.eplepsyres.2012.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 12/12/2011] [Accepted: 01/01/2012] [Indexed: 01/10/2023]
Abstract
The neuronal excitability has been evaluated at various phases of lipopolysaccharide (LPS; E. coli O111:B4, 250 μg/kg, ip)-induced hypothermia including the initial phase, the plateau (including the nadir) and the end of the response in biotelemetered adult Wistar rats. The latency of pentylenetetrazole-induced seizures (60 mg/kg, ip) was lower at the initial phase, but a clear anticonvulsive activity was observed at the end of the hypothermic response. Seizure parameters did not change at the nadir. There was no electroencephalogram (EEG) spike-wave activity generation at either phase of the LPS-induced hypothermia. Meanwhile, the power of the 12-32 Hz beta band of the EEG spectra increased at the initial phase. This increment persisted at the plateau where there was also a decrease in the 1-4 Hz delta power. The data indicate that spike-wave activity is not facilitated during LPS-induced hypothermia but, proconvulsant and anticonvulsant activities occur sequentially depending on the phase of the response. The EEG power spectra also change. These effects may not be attributed merely to the reduction of body temperature. Thus, it is possible that pathophysiological mechanisms involved in the development of hypothermia may also be responsible for neuronal excitability changes in rats.
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Affiliation(s)
- Eyup S Akarsu
- Faculty of Medicine, Department of Medical Pharmacology, Morphology Building, Sihhiye, 06 100 Ankara, Turkey.
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Khoshdel A, Kheiri S, Habibian R, Nozari A, Baradaran A. Lack of association between TNF-α gene polymorphisms at position -308 A, -850T and risk of simple febrile convulsion in pediatric patients. Adv Biomed Res 2012; 1:85. [PMID: 23946933 PMCID: PMC3724328 DOI: 10.4103/2277-9175.105167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Accepted: 03/15/2012] [Indexed: 11/17/2022] Open
Abstract
Background: Febrile convulsions (FCs), occurring between 6 months and 6 years of age is the most common seizure disorder during childhood. The febrile response is thought to be mediated by the release of pyrogenic cytokines, such as tumor necrosis factor and interleukin-1 (IL-1). There is a significant relationship between genetic components for susceptibility of FCs and different report mutation. We investigated association between two polymorphisms in the tumor necrosis factor (TNF)-α promoter region (G-308A, C-850T) and FCs in the southwest area of Iran. Materials and Methods: In this matched case–control study, 100 patients with febrile convulsion as case group and 130 healthy children as control group were enrolled in the study. Peripheral blood samples were collected and DNA was extracted by standard phenol–chloroform method. The genotype and allele frequencies of TNF- α polymorphisms in case and control groups were determined by using PCR-RFLP (polymerase chain reaction restriction fragment length polymorphism) method. Statistical analysis was done using Chi-square test. Results: The average age of case and control groups were 3.4 ± 1.4 and 3.4 ± 1.2 years, respectively. There was no significant difference between age and sex in both the groups (P > 0.05). A family history of febrile convulsion was detected in 44% of patients. Moreover, the simple febrile convulsion was detected in 85% of the case group. Conclusion: RFLP analysis of TNF- α promoter region polymorphisms, considering P = 0.146 and P = 0.084 for G-308A and C-850T, respectively, showed no correlation between TNF- α polymorphisms and predisposition to simple febrile, based on the kind of convulsion (atypical and simple febrile convulsion). We found a significant relation between genotype distribution of G-308A and atypical febrile convulsion in case group (P = 0.04). A significant correlation between genotype distribution of G-308A and atypical febrile convulsion in the case group was found, but there was no correlation between TNF- α polymorphisms at positions of -308A, and 850T and predisposition to simple febrile convulsion. Further studies are needed to understand clinical usefulness of this correlation.
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Affiliation(s)
- Abolfazl Khoshdel
- Department of pediatric, Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran
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Galic MA, Riazi K, Pittman QJ. Cytokines and brain excitability. Front Neuroendocrinol 2012; 33:116-25. [PMID: 22214786 PMCID: PMC3547977 DOI: 10.1016/j.yfrne.2011.12.002] [Citation(s) in RCA: 301] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 12/07/2011] [Accepted: 12/15/2011] [Indexed: 01/21/2023]
Abstract
Cytokines are molecules secreted by peripheral immune cells, microglia, astrocytes and neurons in the central nervous system. Peripheral or central inflammation is characterized by an upregulation of cytokines and their receptors in the brain. Emerging evidence indicates that pro-inflammatory cytokines modulate brain excitability. Findings from both the clinical literature and from in vivo and in vitro laboratory studies suggest that cytokines can increase seizure susceptibility and may be involved in epileptogenesis. Cellular mechanisms that underlie these effects include upregulation of excitatory glutamatergic transmission and downregulation of inhibitory GABAergic transmission.
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Affiliation(s)
- Michael A Galic
- Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, Department of Physiology and Pharmacology, Faculty of Medicine, University of Calgary, Health Sciences Centre, 3330 Hospital Dr. NW, Calgary, Alberta, Canada T2N 4N1
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Interleukin 1 beta −511 C/T gene polymorphism and susceptibility to febrile seizures: a meta-analysis. Mol Biol Rep 2011; 39:5401-7. [DOI: 10.1007/s11033-011-1340-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2011] [Accepted: 12/03/2011] [Indexed: 10/14/2022]
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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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Vezzani A, Aronica E, Mazarati A, Pittman QJ. Epilepsy and brain inflammation. Exp Neurol 2011; 244:11-21. [PMID: 21985866 DOI: 10.1016/j.expneurol.2011.09.033] [Citation(s) in RCA: 404] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2011] [Revised: 09/15/2011] [Accepted: 09/26/2011] [Indexed: 02/06/2023]
Abstract
During the last decade, experimental research has demonstrated a prominent role of glial cells, activated in brain by various injuries, in the mechanisms of seizure precipitation and recurrence. In particular, alterations in the phenotype and function of activated astrocytes and microglial cells have been described in experimental and human epileptic tissue, including modifications in potassium and water channels, alterations of glutamine/glutamate cycle, changes in glutamate receptor expression and transporters, release of neuromodulatory molecules (e.g. gliotransmitters, neurotrophic factors), and induction of molecules involved in inflammatory processes (e.g. cytokines, chemokines, prostaglandins, complement factors, cell adhesion molecules) (Seifert et al., 2006; Vezzani et al., 2011; Wetherington et al., 2008). In particular, brain injury or proconvulsant events can activate microglia and astrocytes to release a number of proinflammatory mediators, thus initiating a cascade of inflammatory processes in brain tissue. Proinflammatory molecules can alter neuronal excitability and affect the physiological functions of glia by paracrine or autocrine actions, thus perturbing the glioneuronal communications. In experimental models, these changes contribute to decreasing the threshold to seizures and may compromise neuronal survival (Riazi et al., 2010; Vezzani et al., 2008). In this context, understanding which are the soluble mediators and the molecular mechanisms crucially involved in glio-neuronal interactions is instrumental to shed light on how brain inflammation may contribute to neuronal hyperexcitability in epilepsy. This review will report the clinical observations in drug-resistant human epilepsies and the experimental findings in adult and immature rodents linking brain inflammation to the epileptic process in a causal and reciprocal manner. By confronting the clinical evidence with the experimental findings, we will discuss the role of specific soluble inflammatory mediators in the etiopathogenesis of seizures, reporting evidence for both their acute and long term effects on seizure threshold. The possible contribution of these mediators to co-morbidities often described in epilepsy patients will be also discussed. Finally, we will report on the anti-inflammatory treatments with anticonvulsant actions in experimental models highlighting possible therapeutic options for treating drug-resistant seizures and for prevention of epileptogenesis.
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Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Via G. La Masa 19, 20156 Milano, Italy.
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Friedman A, Dingledine R. Molecular cascades that mediate the influence of inflammation on epilepsy. Epilepsia 2011; 52 Suppl 3:33-9. [PMID: 21542844 DOI: 10.1111/j.1528-1167.2011.03034.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Experimental evidence strongly indicates a significant role for inflammatory and immune mediators in initiation of seizures and epileptogenesis. Here we will summarize data supporting the involvement of IL-1β, TNF-α and toll-like receptor 4 in seizure generation and the process of epileptogenesis. The physiological homeostasis and control over brain immune response depends on the integrity of the blood-brain barrier, transforming growth factor (TGF)-β signaling and leukocyte migration. To what extent targeting the immune system is successful in preventing epileptogenesis, and which signaling pathway should be beleaguered is still under intensive research.
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Affiliation(s)
- Alon Friedman
- Department of Physiology and Neurobiology, Faculty of Health Sciences, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
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Ichikawa J, Matsuki N, Koyama R. [Influences of febrile seizures on developing neuronal circuits: cellular and molecular approaches using animal models]. Nihon Yakurigaku Zasshi 2010; 136:219-24. [PMID: 20948158 DOI: 10.1254/fpj.136.219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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