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Rubio C, Gatica F, Portila A, Vázquez D, Molina-García J, Piñón E, Rubio-Osornio M. Rats in Epilepsy Research: A Bibliometric Analysis of Citations Between 1969 and 2020 on Experimental Models in Epilepsy. Cureus 2023; 15:e48891. [PMID: 38106753 PMCID: PMC10725118 DOI: 10.7759/cureus.48891] [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] [Accepted: 11/08/2023] [Indexed: 12/19/2023] Open
Abstract
Epilepsy stands as a prominent neurological disorder, affecting a substantial number of individuals who, unfortunately, do not respond to conventional antiepileptic medications. To unravel the intricate mechanisms underlying epileptic seizures and explore potential therapeutic avenues, researchers have turned to animal models. Among these models, rats have emerged as one of the cornerstones of epilepsy research. This bibliometric analysis embarks on the crucial task of delving into the role of rat models in deciphering the mysteries of epileptic seizures and, notably, pinpointing the most prevalent models in use. Our study harnessed Scopus' citation tracking feature to review a range of research papers dating from 1969 to 2020, all dedicated to the exploration of epileptic seizures in rats. The citations that emerged from this rigorous process were subjected to thematic coding, primarily centered around the specific epileptic animal models employed, and subsequently, comprehensive descriptive statistics were computed. In this effort, we found a total of 1,318 publications that explore the world of rat studies, accumulating a substantial citation count of 44,824 references. This analysis illuminated the invaluable role that research employing rat models has played in shaping our current clinical understanding of epileptic seizures. Notably, several models have emerged as predominant forces in this field, including those induced by pilocarpine, pentylenetetrazole (PTZ), kainic acid (KA), electric kindling, and electroshock. This bibliometric exploration serves as a resounding reminder of the pivotal position that rat models occupy in advancing our comprehension of epilepsy. These findings resonate strongly, underscoring the continued importance of directing research and development funding toward this debilitating disorder, with the ultimate aim of maximizing the benefits for the patients grappling with this condition. The potential to revolutionize our approach to epilepsy and enhance the quality of life for those affected remains a beacon of hope, illuminated by the contributions of these tireless researchers and their trusty rat companions.
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Affiliation(s)
- Carmen Rubio
- Neurophysiology, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, MEX
| | - Fernando Gatica
- Neurophysiology, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, MEX
| | - Alonso Portila
- Neurophysiology, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, MEX
| | - David Vázquez
- Neurophysiology, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, MEX
| | - José Molina-García
- Neurophysiology, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, MEX
| | - Ernesto Piñón
- Neurophysiology, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, MEX
| | - Moisés Rubio-Osornio
- Neurochemistry, Instituto Nacional de Neurología y Neurocirugía, Ciudad de México, MEX
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Dai SJ, Shao YY, Zheng Y, Sun JY, Li ZS, Shi JY, Yan MQ, Qiu XY, Xu CL, Cho WS, Nishibori M, Yi S, Park SB, Wang Y, Chen Z. Inflachromene attenuates seizure severity in mouse epilepsy models via inhibiting HMGB1 translocation. Acta Pharmacol Sin 2023; 44:1737-1747. [PMID: 37076634 PMCID: PMC10462729 DOI: 10.1038/s41401-023-01087-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 04/02/2023] [Indexed: 04/21/2023] Open
Abstract
Epilepsy is not well controlled by current anti-seizure drugs (ASDs). High mobility group box 1 (HMGB1) is a DNA-binding protein in the nucleus regulating transcriptional activity and maintaining chromatin structure and DNA repair. In epileptic brains, HMGB1 is released by activated glia and neurons, interacting with various receptors like Toll-like receptor 4 (TLR4) and downstream glutamatergic NMDA receptor, thus enhancing neural excitability. But there is a lack of small-molecule drugs targeting the HMGB1-related pathways. In this study we evaluated the therapeutic potential of inflachromene (ICM), an HMGB-targeting small-molecule inhibitor, in mouse epilepsy models. Pentylenetetrazol-, kainic acid- and kindling-induced epilepsy models were established in mice. The mice were pre-treated with ICM (3, 10 mg/kg, i.p.). We showed that ICM pretreatment significantly reduced the severity of epileptic seizures in all the three epilepsy models. ICM (10 mg/kg) exerted the most apparent anti-seizure effect in kainic acid-induced epileptic status (SE) model. By immunohistochemical analysis of brain sections from kainic acid-induced SE mice, we found that kainic acid greatly enhanced HMGB1 translocation in the hippocampus, which was attenuated by ICM pretreatment in subregion- and cell type-dependent manners. Notably, in CA1 region, the seizure focus, ICM pretreatment mainly inhibited HMGB1 translocation in microglia. Furthermore, the anti-seizure effect of ICM was related to HMGB1 targeting, as pre-injection of anti-HMGB1 monoclonal antibody (5 mg/kg, i.p.) blocked the seizure-suppressing effect of ICM in kainic acid-induced SE model. In addition, ICM pretreatment significantly alleviated pyramidal neuronal loss and granule cell dispersion in kainic acid-induced SE model. These results demonstrate that ICM is an HMGB-targeting small molecule with anti-seizure potential, which may help develop a potential drug for treating epilepsy.
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Affiliation(s)
- Si-Jie Dai
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Yu-Ying Shao
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Yang Zheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Jin-Yi Sun
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Zhi-Sheng Li
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Jia-Ying Shi
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Meng-Qi Yan
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Xiao-Yun Qiu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Ceng-Lin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Wan-Sang Cho
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Masahiro Nishibori
- Department of Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Sihyeong Yi
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seung Bum Park
- CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul, 08826, Republic of Korea
| | - Yi Wang
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China.
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, College of Pharmaceutical Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China.
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
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de Melo AD, Freire VAF, Diogo ÍL, Santos HDL, Barbosa LA, de Carvalho LED. Antioxidant Therapy Reduces Oxidative Stress, Restores Na,K-ATPase Function and Induces Neuroprotection in Rodent Models of Seizure and Epilepsy: A Systematic Review and Meta-Analysis. Antioxidants (Basel) 2023; 12:1397. [PMID: 37507936 PMCID: PMC10376594 DOI: 10.3390/antiox12071397] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/05/2023] [Accepted: 06/08/2023] [Indexed: 07/30/2023] Open
Abstract
Epilepsy is a neurological disorder characterized by epileptic seizures resulting from neuronal hyperexcitability, which may be related to failures in Na,K-ATPase activity and oxidative stress participation. We conducted this study to investigate the impact of antioxidant therapy on oxidative stress, Na,K-ATPase activity, seizure factors, and mortality in rodent seizure/epilepsy models induced by pentylenetetrazol (PTZ), pilocarpine (PILO), and kainic acid (KA). After screening 561 records in the MEDLINE, EMBASE, Web of Science, Science Direct, and Scopus databases, 22 were included in the systematic review following the PRISMA guidelines. The meta-analysis included 14 studies and showed that in epileptic animals there was an increase in the oxidizing agents nitric oxide (NO) and malondialdehyde (MDA), with a reduction in endogenous antioxidants reduced glutathione (GSH) and superoxide dismutase (SO). The Na,K-ATPase activity was reduced in all areas evaluated. Antioxidant therapy reversed all of these parameters altered by seizure or epilepsy induction. In addition, there was a percentage decrease in the number of seizures and mortality, and a meta-analysis showed a longer seizure latency in animals using antioxidant therapy. Thus, this study suggests that the use of antioxidants promotes neuroprotective effects and mitigates the effects of epilepsy. The protocol was registered in the Prospective Register of Systematic Reviews (PROSPERO) CRD42022356960.
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Affiliation(s)
- Anderson Dutra de Melo
- Departamento de Ciências e Linguagens, Instituto Federal de Minas Gerais, Bambui 38900-000, Minas Gerais, Brazil
- Laboratório de Bioquímica Celular, Universidade Federal de São João Del Rei, Divinopolis 35501-296, Minas Gerais, Brazil
| | - Victor Antonio Ferreira Freire
- Laboratório de Bioquímica Celular, Universidade Federal de São João Del Rei, Divinopolis 35501-296, Minas Gerais, Brazil
| | - Ítalo Leonardo Diogo
- Laboratório de Bioquímica Celular, Universidade Federal de São João Del Rei, Divinopolis 35501-296, Minas Gerais, Brazil
| | - Hérica de Lima Santos
- Laboratório de Bioquímica Celular, Universidade Federal de São João Del Rei, Divinopolis 35501-296, Minas Gerais, Brazil
| | - Leandro Augusto Barbosa
- Laboratório de Bioquímica Celular, Universidade Federal de São João Del Rei, Divinopolis 35501-296, Minas Gerais, Brazil
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Jiang G, Wang S, Chen M, Ding X, He W, Wang L, Wang S, Yu J, Wang X. Linsitinib (OSI-906) modulates brain energy metabolism and seizure activity in the lithium-pilocarpine rat model. ACTA EPILEPTOLOGICA 2021. [DOI: 10.1186/s42494-021-00054-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Epileptic seizure is a process of energy accumulation, bursting, and depletion accompanied by the production, spread, and termination of epileptic discharges. The energy required for a seizure is mainly provided through mitochondrial production of ATP. Mitochondrial diseases often lead to epileptic seizures, and energy depletion caused by seizures can lead to mitochondrial dysfunction. The energy metabolism has become a key target for treatment of epileptic diseases.
Method
The effect of OSI-906, an insulin receptor (IR)/ insulin-like growth factor 1 receptor (IGF-1R) inhibitor, on behaviors and electroencephalographic activity in the lithium-pilocarpine rats were tested. 18F-FDG positron emission tomography (PET)/ computed tomography (CT) was performed to detect the relative whole-brain glucose uptake values. Electron microscopy was performed to observe the ultrastructure of neuronal and mitochondrial damage. The changes in blood glucose at different time points before and after the intervention were tested and the effects of OSI-906 on IR/IGF-1R and downstream Akt signaling in the context of seizures were evaluated.
Results
The OSI-906 treatment applied 3 days before the pilocarpine-induced seizures significantly reduced the seizure severity, prolonged the seizure latency and decreased the EEG energy density. MicroPET/CT revealed that 50 mg/kg of OSI-906 inhibited the 18F-FDG glucose uptake after epileptic seizures, suggesting that OSI-906, through inhibiting IR/IGF-1R and the downstream AKT signaling, may regulate the excessive energy consumption of the epileptic brain. The OSI-906 treatment also reduced the mitochondrial damage caused by epileptic seizures.
Conclusion
The IR/IGF-1R inhibitor OSI-906 can significantly reduce the sensitivity and severity of pilocarpine-induced seizures by inhibiting the IR/IGF-1R and the downstream Akt signaling pathway.
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Lourenço DM, Ribeiro-Rodrigues L, Sebastião AM, Diógenes MJ, Xapelli S. Neural Stem Cells and Cannabinoids in the Spotlight as Potential Therapy for Epilepsy. Int J Mol Sci 2020; 21:E7309. [PMID: 33022963 PMCID: PMC7582633 DOI: 10.3390/ijms21197309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 09/28/2020] [Accepted: 09/30/2020] [Indexed: 01/18/2023] Open
Abstract
Epilepsy is one of the most common brain diseases worldwide, having a huge burden in society. The main hallmark of epilepsy is the occurrence of spontaneous recurrent seizures, having a tremendous impact on the lives of the patients and of their relatives. Currently, the therapeutic strategies are mostly based on the use of antiepileptic drugs, and because several types of epilepsies are of unknown origin, a high percentage of patients are resistant to the available pharmacotherapy, continuing to experience seizures overtime. Therefore, the search for new drugs and therapeutic targets is highly important. One key aspect to be targeted is the aberrant adult hippocampal neurogenesis (AHN) derived from Neural Stem Cells (NSCs). Indeed, targeting seizure-induced AHN may reduce recurrent seizures and shed some light on the mechanisms of disease. The endocannabinoid system is a known modulator of AHN, and due to the known endogenous antiepileptic properties, it is an interesting candidate for the generation of new antiepileptic drugs. However, further studies and clinical trials are required to investigate the putative mechanisms by which cannabinoids can be used to treat epilepsy. In this manuscript, we will review how cannabinoid-induced modulation of NSCs may promote neural plasticity and whether these drugs can be used as putative antiepileptic treatment.
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Affiliation(s)
- Diogo M. Lourenço
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (D.M.L.); (L.R.-R.); (A.M.S.); (M.J.D.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Leonor Ribeiro-Rodrigues
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (D.M.L.); (L.R.-R.); (A.M.S.); (M.J.D.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Ana M. Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (D.M.L.); (L.R.-R.); (A.M.S.); (M.J.D.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Maria J. Diógenes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (D.M.L.); (L.R.-R.); (A.M.S.); (M.J.D.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Sara Xapelli
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal; (D.M.L.); (L.R.-R.); (A.M.S.); (M.J.D.)
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
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Li J, Copmans D, Partoens M, Hunyadi B, Luyten W, de Witte P. Zebrafish-Based Screening of Antiseizure Plants Used in Traditional Chinese Medicine: Magnolia officinalis Extract and Its Constituents Magnolol and Honokiol Exhibit Potent Anticonvulsant Activity in a Therapy-Resistant Epilepsy Model. ACS Chem Neurosci 2020; 11:730-742. [PMID: 32083464 DOI: 10.1021/acschemneuro.9b00610] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
With the aim to discover interesting lead compounds that could be further developed into compounds active against pharmacoresistant epilepsies, we first collected 14 medicinal plants used in traditional Chinese medicine (TCM) against epilepsy. Of the six extracts that tested positive in a pentylenetetrazole (PTZ) behavioral zebrafish model, only the ethanol and acetone extracts from Magnolia officinalis (M. officinalis) also showed effective antiseizure activity in the ethylketopentenoate (EKP) zebrafish model. The EKP model is regarded as an interesting discovery platform to find mechanistically novel antiseizure drugs, as it responds poorly to a large number of marketed anti-epileptics. We then demonstrated that magnolol and honokiol, two major constituents of M. officinalis, displayed an effective behavioral and electrophysiological antiseizure activity in both the PTZ and the EKP models. Out of six structural analogues tested, only 4-O-methylhonokiol was active and to a lesser extent tetrahydromagnolol, whereas the other analogues (3,3'-dimethylbiphenyl, 2,2'-biphenol, 2-phenylphenol, and 3,3',5,5'-tetra-tert-butyl-[1,1'-biphenyl]-2,2'-diol) were not consistently active in the aforementioned assays. Finally, magnolol was also active in the 6 Hz psychomotor mouse model, an acute therapy-resistant rodent model, thereby confirming the translation of the findings from zebrafish larvae to mice in the field of epilepsy. We also developed a fast and automated power spectral density (PSD) analysis of local field potential (LFP) recordings. The PSD results are in agreement with the visual analysis of LFP recordings using Clampfit software and manually counting the epileptiform events. Taken together, screening extracts of single plants employed in TCM, using a combination of zebrafish- and mouse-based assays, allowed us to identify allyl biphenol as a chemical scaffold for the future development of compounds with potential activity against therapy-resistant epilepsies.
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Affiliation(s)
- Jing Li
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Daniëlle Copmans
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Michèle Partoens
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Borbála Hunyadi
- STADIUS Center for Dynamical Systems, Signal Processing and Data Analytics, Department of Electrical Engineering (ESAT), KU Leuven, 3001 Leuven, Belgium
| | - Walter Luyten
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Peter de Witte
- Laboratory for Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
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Lazarini-Lopes W, Do Val-da Silva RA, da Silva-Júnior RMP, Leite JP, Garcia-Cairasco N. The anticonvulsant effects of cannabidiol in experimental models of epileptic seizures: From behavior and mechanisms to clinical insights. Neurosci Biobehav Rev 2020; 111:166-182. [PMID: 31954723 DOI: 10.1016/j.neubiorev.2020.01.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/21/2019] [Accepted: 01/14/2020] [Indexed: 02/06/2023]
Abstract
Epilepsy is a neurological disorder characterized by the presence of seizures and neuropsychiatric comorbidities. Despite the number of antiepileptic drugs, one-third of patients did not have their seizures under control, leading to pharmacoresistance epilepsy. Cannabis sativa has been used since ancient times in Medicine for the treatment of many diseases, including convulsive seizures. In this context, Cannabidiol (CBD), a non-psychoactive phytocannabinoid present in Cannabis, has been a promising compound for treating epilepsies due to its anticonvulsant properties in animal models and humans, especially in pharmacoresistant patients. In this review, we summarize evidence of the CBD anticonvulsant activities present in a great diversity of animal models. Special attention was given to behavioral CBD effects and its translation to human epilepsies. CBD anticonvulsant effects are associated with a great variety of mechanisms of action such as endocannabinoid and calcium signaling. CBD has shown effectiveness in the clinical scenario for epilepsies, but its effects on epilepsy-related comorbidities are scarce even in basic research. More detailed and complex behavioral evaluation about CBD effects on seizures and epilepsy-related comorbidities are required.
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Affiliation(s)
- Willian Lazarini-Lopes
- Neuroscience and Behavioral Sciences Department, Ribeirão Preto School of Medicine, University of São Paulo, Brazil; Neurophysiology and Experimental Neuroethology Laboratory, Physiology Department, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, Brazil.
| | - Raquel A Do Val-da Silva
- Neuroscience and Behavioral Sciences Department, Ribeirão Preto School of Medicine, University of São Paulo, Brazil.
| | - Rui M P da Silva-Júnior
- Neurophysiology and Experimental Neuroethology Laboratory, Physiology Department, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, Brazil.
| | - João P Leite
- Neuroscience and Behavioral Sciences Department, Ribeirão Preto School of Medicine, University of São Paulo, Brazil.
| | - Norberto Garcia-Cairasco
- Neuroscience and Behavioral Sciences Department, Ribeirão Preto School of Medicine, University of São Paulo, Brazil; Neurophysiology and Experimental Neuroethology Laboratory, Physiology Department, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, Brazil.
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Protein Kinase A-Mediated Suppression of the Slow Afterhyperpolarizing KCa3.1 Current in Temporal Lobe Epilepsy. J Neurosci 2019; 39:9914-9926. [PMID: 31672789 DOI: 10.1523/jneurosci.1603-19.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 09/24/2019] [Accepted: 10/07/2019] [Indexed: 01/01/2023] Open
Abstract
Brain insults, such as trauma, stroke, anoxia, and status epilepticus (SE), cause multiple changes in synaptic function and intrinsic properties of surviving neurons that may lead to the development of epilepsy. Experimentally, a single SE episode, induced by the convulsant pilocarpine, initiates the development of an epileptic condition resembling human temporal lobe epilepsy (TLE). Principal hippocampal neurons from such epileptic animals display enhanced spike output in response to excitatory stimuli compared with neurons from nonepileptic animals. This enhanced firing is negatively related to the size of the slow afterhyperpolarization (sAHP), which is reduced in the epileptic neurons. The sAHP is an intrinsic neuronal negative feedback mechanism consisting normally of two partially overlapping components produced by disparate mechanisms. One component is generated by activation of Ca2+-gated K+ (KCa) channels, likely KCa3.1, consequent to spike Ca2+ influx (the KCa-sAHP component). The second component is generated by enhancement of the electrogenic Na+/K+ ATPase (NKA) by spike Na+ influx (NKA-sAHP component). Here we show that the KCa-sAHP component is markedly reduced in male rat epileptic neurons, whereas the NKA-sAHP component is not altered. The KCa-sAHP reduction is due to the downregulation of KCa3.1 channels, mediated by cAMP-dependent protein kinase A (PKA). This sustained effect can be acutely reversed by applying PKA inhibitors, leading also to normalization of the spike output of epileptic neurons. We propose that the novel "acquired channelopathy" described here, namely, PKA-mediated downregulation of KCa3.1 activity, provides an innovative target for developing new treatments for TLE, hopefully overcoming the pharmacoresistance to traditional drugs.SIGNIFICANCE STATEMENT Epilepsy, a common neurological disorder, often develops following a brain insult. Identifying key molecular and cellular mechanisms underlying acquired epilepsy is critical for developing effective antiepileptic therapies. In an experimental model of acquired epilepsy, we show that principal hippocampal neurons become intrinsically hyperexcitable. This alteration is due predominantly to the downregulation of a ubiquitous class of potassium ion channels, KCa3.1, whose main function is to dampen neuronal excitability. KCa3.1 downregulation is mediated by the cAMP-dependent protein kinase A (PKA) signaling pathway. Most importantly, it can be acutely reversed by PKA inhibitors, leading to recovery of KCa3.1 function and normalization of neuronal excitability. The discovery of this novel epileptogenic mechanism hopefully will facilitate the development of more efficient pharmacotherapy for acquired epilepsy.
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Bortel A, Yao ZS, Shmuel A. A rat model of somatosensory-evoked reflex seizures induced by peripheral stimulation. Epilepsy Res 2019; 157:106209. [PMID: 31629247 DOI: 10.1016/j.eplepsyres.2019.106209] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/31/2019] [Accepted: 09/19/2019] [Indexed: 01/14/2023]
Abstract
OBJECTIVE We introduce a novel animal model of somatosensory stimulation-induced reflex seizures which generates focal seizures without causing damage to the brain. METHODS Specifically, we electrically stimulated digits or forepaws of adult rats sedated with dexmedetomidine while imaging cerebral blood volume and recording neurophysiological activity in cortical area S1FL. For the recordings, we either inserted a linear probe into the D3 digit representation or we performed surface electrocorticography (ECoG) recordings. RESULTS Peripheral stimulation of a digit or the forepaw elicited seizures that were followed by a refractory period with decreased neuronal activity, or another seizure or normal response. LFP amplitudes in response to electrical pulses during the seizures (0.28 ± 0.03 mV) were higher than during normal evoked responses (0.25 ± 0.05 mV) and refractory periods (0.2 ± 0.08 mV). Seizures generated during the stimulation period showed prolonged after-discharges that were sustained for 20.9 ± 1.9 s following the cessation of the stimulus. High-frequency oscillations were observed prior to and during the seizures, with amplitudes higher than those associated with normal evoked responses. The seizures were initially focal. Optical imaging of the cerebral blood volume response showed that they propagated from the onset zone to adjacent cortical areas, beyond the S1FL representation of the stimulated digit or forepaw. The spatial extent during seizures was on average 1.74 times larger during the stimulation and 4.1 times following its cessation relative to normal evoked responses. Seizures were recorded not only by probes inserted into cortex but also with ECoG arrays (24.1 ± 5.8 seizures per rat) placed over the dura matter, indicating that the seizures were not induced by damage caused by inserting the probes to the cortex. Stimulation of the forepaw elicited more seizures (18.8 ± 8.5 seizures per rat) than stimulation of a digit (1.7 ± 0.7). Unlike rats sedated with dexmedetomidine, rats anesthetized with urethane showed no seizures, indicating that the seizures may depend on the use of the mild sedative dexmedetomidine. SIGNIFICANCE Our proposed animal model generates seizures induced by electrical sensory stimulation free of artifacts and brain damage. It can be used for studying the mechanisms underlying the generation and propagation of reflex seizures and for evaluating antiepileptic drugs.
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Affiliation(s)
- Aleksandra Bortel
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, H3A 2B4, Canada.
| | - Ze Shan Yao
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Biomedical Engineering, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Amir Shmuel
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Physiology, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Biomedical Engineering, McGill University, Montreal, QC, H3A 2B4, Canada.
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10
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Ren T, Xiao M, Yang M, Zhao J, Zhang Y, Hu M, Cheng Y, Xu H, Zhang C, Yan X, Zuo Z. Reduced Systemic and Brain Exposure with Inhibited Liver Metabolism of Carbamazepine After Its Long-Term Combination Treatment with Piperine for Epilepsy Control in Rats. AAPS JOURNAL 2019; 21:90. [DOI: 10.1208/s12248-019-0357-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 06/24/2019] [Indexed: 01/16/2023]
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11
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Piperine-loaded nanoparticles with enhanced dissolution and oral bioavailability for epilepsy control. Eur J Pharm Sci 2019; 137:104988. [PMID: 31291598 DOI: 10.1016/j.ejps.2019.104988] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 06/28/2019] [Accepted: 07/06/2019] [Indexed: 11/23/2022]
Abstract
Piperine, an alkaloid from black pepper, has demonstrated beneficial effects in central nervous system, especially in epilepsy control. However, its therapeutic application remains limited due to the low aqueous solubility of piperine. Thus, the present study aimed to formulate piperine into a more solubilized form to enhance its oral bioavailability and facilitate its development as a potential anti-epileptic treatment. The nanoprecipitation method was applied to prepare piperine nanoparticles, which were then examined under transmission electron microscopy. A spherical nanosized particle was obtained with small particle size (average particle size 130.20 ± 1.57 nm), narrow size distribution (polydispersity index 0.195 ± 0.002) and efficient entrapment (entrapment efficiency 92.2 ± 2.5%). Compared with the unformulated piperine, nanosized piperine had a much faster dissolution rate with 3 times higher accumulated drug release after 24 h. After oral administration at 3.5 mg/kg in rats, the nanosized piperine formulations could improve its oral bioavailability by 2.7-fold with 16 times higher concentrations in brain at 10 h postdosing. Moreover, the piperine nanoparticles exhibited effective protection against pentylenetetrazol-induced seizures in both zebrafish and mice. In summary, the present study provided a simple formulation strategy for oral administration of piperine to overcome its limitation in water solubility. The developed formulations could effectively enhance oral bioavailability of piperine with promising anti-epileptic effect, which could be applied as a potential therapy in epilepsy control.
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12
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Liu Y, Hou B, Zhang Y, Fan Y, Peng B, Liu W, Han S, Yin J, He X. Anticonvulsant agent DPP4 inhibitor sitagliptin downregulates CXCR3/RAGE pathway on seizure models. Exp Neurol 2018; 307:90-98. [PMID: 29885296 DOI: 10.1016/j.expneurol.2018.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 05/09/2018] [Accepted: 06/05/2018] [Indexed: 12/11/2022]
Abstract
Epilepsy is a common neurological disorder with a complex etiology. Our previous study demonstrated that dipeptidyl peptidase IV (DPP4) may be associated with the pathogenesis of epilepsy. However, whether the DPP4 inhibitor sitagliptin has an anticonvulsant effect and the underlying mechanism remain to be elucidated. In this study, we determined that sitagliptin remarkably attenuated the severity of seizures in a pentylenetetrazole (PTZ)-induced rat model. In addition, sitagliptin decreased epileptiform activity measured by electroencephalography (EEG) recordings and patch-clamp methods. Interestingly, sitagliptin pretreatment downregulated the RAGE-JAK2/STAT3 pathway and decreased the expression of CXCL4 and CXCR3. Moreover, CXCR3 knockdown decreased the expression of RAGE, JAK2 and STAT3 in cultured neurons, which suggests that CXCR3 is upstream of the RAGE-JAK2/STAT3 pathway. Altogether, our present data suggest that sitagliptin has an anticonvulsant effect, which might act via downregulation of the CXCL4/CXCR3 axis, followed by a decrease in RAGE and JAK2/STAT3 expression. Considering these effects, sitagliptin could be considered as a novel potential anticonvulsant drug.
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Affiliation(s)
- Yunli Liu
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Baohua Hou
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Yusong Zhang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China; Department of Pathology, Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yuanteng Fan
- Department of Neurology, Zhongnan Hospital, Wuhan University, Wuhan, China
| | - Biwen Peng
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Wanhong Liu
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Song Han
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Jun Yin
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.
| | - Xiaohua He
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.
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13
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Lippert T, Gelineau L, Napoli E, Borlongan CV. Harnessing neural stem cells for treating psychiatric symptoms associated with fetal alcohol spectrum disorder and epilepsy. Prog Neuropsychopharmacol Biol Psychiatry 2018; 80:10-22. [PMID: 28365374 DOI: 10.1016/j.pnpbp.2017.03.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 03/09/2017] [Indexed: 12/20/2022]
Abstract
Brain insults with progressive neurodegeneration are inherent in pathological symptoms that represent many psychiatric illnesses. Neural network disruptions characterized by impaired neurogenesis have been recognized to precede, accompany, and possibly even exacerbate the evolution and progression of symptoms of psychiatric disorders. Here, we focus on the neurodegeneration and the resulting psychiatric symptoms observed in fetal alcohol spectrum disorder and epilepsy, in an effort to show that these two diseases are candidate targets for stem cell therapy. In particular, we provide preclinical evidence in the transplantation of neural stem cells (NSCs) in both conditions, highlighting the potential of this cell-based treatment for correcting the psychiatric symptoms that plague these two disorders. Additionally, we discuss the challenges of NSC transplantation and offer insights into the mechanisms that may mediate the therapeutic benefits and can be exploited to overcome the hurdles of translating this therapy from the laboratory to the clinic. Our ultimate goal is to advance stem cell therapy for the treatment of psychiatric disorders.
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Affiliation(s)
- Trenton Lippert
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery and Brain Repair, University of South Florida College of Medicine, 12901 Bruce B. Downs Blvd. MDC 78, Tampa, FL 33612, USA
| | - Lindsey Gelineau
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery and Brain Repair, University of South Florida College of Medicine, 12901 Bruce B. Downs Blvd. MDC 78, Tampa, FL 33612, USA
| | - Eleonora Napoli
- Department of Molecular Biosciences, 3011 VM3B 1089 Veterinary Medicine Drive, University of California Davis, Davis, CA 95616, USA..
| | - Cesar V Borlongan
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery and Brain Repair, University of South Florida College of Medicine, 12901 Bruce B. Downs Blvd. MDC 78, Tampa, FL 33612, USA.
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14
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Lopes MA, Lee KE, Goltsev AV. Neuronal network model of interictal and recurrent ictal activity. Phys Rev E 2017; 96:062412. [PMID: 29347379 DOI: 10.1103/physreve.96.062412] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Indexed: 02/04/2023]
Abstract
We propose a neuronal network model which undergoes a saddle node on an invariant circle bifurcation as the mechanism of the transition from the interictal to the ictal (seizure) state. In the vicinity of this transition, the model captures important dynamical features of both interictal and ictal states. We study the nature of interictal spikes and early warnings of the transition predicted by this model. We further demonstrate that recurrent seizures emerge due to the interaction between two networks.
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Affiliation(s)
- M A Lopes
- Living Systems Institute, University of Exeter, Exeter EX4 4QD, United Kingdom.,Wellcome Trust Centre for Biomedical Modelling and Analysis, University of Exeter, Exeter EX4 4QD, United Kingdom.,EPSRC Centre for Predictive Modelling in Healthcare, University of Exeter, Exeter EX4 4QD, United Kingdom.,Department of Physics and I3N, University of Aveiro, 3810-193 Aveiro, Portugal
| | - K-E Lee
- Department of Physics and I3N, University of Aveiro, 3810-193 Aveiro, Portugal.,Department of Anesthesiology and Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
| | - A V Goltsev
- Department of Physics and I3N, University of Aveiro, 3810-193 Aveiro, Portugal.,A.F. Ioffe Physico-Technical Institue, 194021 St. Petersburg, Russia
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15
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Adongo DW, Mante PK, Kukuia KKE, Biney RP, Boakye-Gyasi E, Benneh CK, Ameyaw EO, Woode E. Anticonvulsant activity of Pseudospondias microcarpa (A. Rich) Engl. hydroethanolic leaf extract in mice: The role of excitatory/inhibitory neurotransmission and nitric oxide pathway. JOURNAL OF ETHNOPHARMACOLOGY 2017; 206:78-91. [PMID: 28528187 DOI: 10.1016/j.jep.2017.05.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 05/09/2017] [Accepted: 05/10/2017] [Indexed: 06/07/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Pseudospondias microcarpa (A. Rich) Engl. is a plant used for managing various diseases including central nervous system disorders. AIM OF THE STUDY This study explored the anticonvulsant activity of P. microcarpa hydroethanolic leaf extract (PME) as well as possible mechanism(s) of action in animal models. METHODS Effects of PME was assessed in electroconvulsive (the maximal electroshock and 6-Hz seizures) and chemoconvulsive (pentylenetetrazole-, picrotoxin-, isoniazid-, 4-aminopyridine-, and strychnine-induced seizures) models of epilepsy. In addition, effect of the extract on the nitric oxide pathway and GABAA receptor complex was evaluated. RESULTS The extract (30, 100 and 300mgkg-1, p.o.) significantly delayed the onset as well as decreased the duration and frequency of pentylenetetrazole-, picrotoxin- and strychnine-induced seizures. In addition, PME pre-treatment significantly improved survival in the 4-aminopyridine- and isoniazid-induced seizure tests. Furthermore, the extract protected against 6-Hz psychomotor seizures but had no effect in the maximal electroshock test. The anticonvulsant effect of PME (100mgkg-1, p.o.) was also reversed by pre-treatment with flumazenil, L-arginine or sildenafil. However, L-NAME or methylene blue (MB) augmented its effect. CONCLUSION Results show that PME has anticonvulsant activity and may probably be affecting GABAergic, glycinergic, NMDA, K+ channels and nitric oxide-cGMP pathways to exert its effect.
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Affiliation(s)
- Donatus W Adongo
- Department of Pharmacology, School of Medicine, University of Health and Allied Sciences, Ho, Ghana.
| | - Priscilla K Mante
- Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
| | - Kennedy K E Kukuia
- Department of Pharmacology and Toxicology, University of Ghana School of Pharmacy, University of Ghana, Accra, Ghana.
| | - Robert P Biney
- Department of Pharmacology, School of Medical Sciences, University of Cape Coast, Cape Coast, Ghana.
| | - Eric Boakye-Gyasi
- Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
| | - Charles K Benneh
- Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
| | - Elvis O Ameyaw
- Department of Biomedical and Forensic Sciences, School of Biological Science, University of Cape Coast, Cape Coast, Ghana.
| | - Eric Woode
- Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
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Chwiej J, Patulska A, Skoczen A, Matusiak K, Janeczko K, Ciarach M, Simon R, Setkowicz Z. Various ketogenic diets can differently support brain resistance against experimentally evoked seizures and seizure-induced elemental anomalies of hippocampal formation. J Trace Elem Med Biol 2017; 42:50-58. [PMID: 28595792 DOI: 10.1016/j.jtemb.2017.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 03/13/2017] [Accepted: 04/04/2017] [Indexed: 01/09/2023]
Abstract
In this paper the influence of two different ketogenic diets (KDs) on the seizure-evoked elemental anomalies of hippocampal formation was examined. To achieve this purpose normal and pilocarpine treated rats previously fed with one of the two high fat and carbohydrate restricted diets were compared with animals on standard laboratory diet. The ketogenic ratios of the examined KDs were equal to 5:1 (KD1) and 9:1 (KD2). KD1 and standard diet fed animals presented similar patterns of seizure-evoked elemental changes in hippocampal formation. Also the analysis of behavioral data recorded after pilocarpine injection did not show any significant differences in intensity and duration of seizures between KD1 and standard diet fed animals. Higher ketogenic ratio KD2 introduced in the normal hippocampal formation prolonged changes in the accumulation of P, K, Zn and Ca. Despite this, both the intensity and duration of seizures were significantly reduced in rats fed with KD2 which suggests that its saving action on the nerve tissue may protect brain from seizure propagation. Also seizure-evoked elemental anomalies in KD2 animals were different than those observed for rats both on KD1 and standard diets. The comparison of seizure experiencing and normal rats on KD2, did not show any statistically significant differences in elemental composition of CA1 and H hippocampal areas whilst in CA3 area only Zn level changed as a result of seizures. DG was the area mostly affected by seizures in KD2 fed rats but areal densities of all examined elements increased in this hippocampal region.
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Affiliation(s)
- J Chwiej
- AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakow, Poland.
| | - A Patulska
- AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakow, Poland
| | - A Skoczen
- AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakow, Poland
| | - K Matusiak
- AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakow, Poland
| | - K Janeczko
- Jagiellonian University, Institute of Zoology, Krakow, Poland
| | - M Ciarach
- Jagiellonian University, Institute of Zoology, Krakow, Poland
| | - R Simon
- Institut fur Synchrotronstrahlung, Research Centre Karlsruhe, Karlsruhe, Germany
| | - Z Setkowicz
- Jagiellonian University, Institute of Zoology, Krakow, Poland
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17
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Tamir I, Daninos M, Yaari Y. Plasticity of intrinsic firing response gain in principal hippocampal neurons following pilocarpine-induced status epilepticus. Neuroscience 2017. [PMID: 28624573 DOI: 10.1016/j.neuroscience.2017.06.013] [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] [Indexed: 01/24/2023]
Abstract
OBJECTIVE In experimental models of temporal lobe epilepsy (TLE), brain neurons manifest multiple changes in intrinsic excitability that contribute to neuronal network hyperexcitability. We have investigated whether the intrinsic firing response gain, quantified by the slope of the function relating the number of evoked spikes (Ns) to input excitatory current intensity (I), is modified in principal rat hippocampal neurons in the pilocarpine-status epilepticus (SE) model of TLE. METHODS Intracellular recordings were made in CA3 and CA1 pyramidal cells (PCs) and dentate granule cells (GCs) in acute hippocampal slices obtained 7-36days after pilocarpine-SE. Firing response gains were determined empirically from Ns/I relationships and compared to other measured neuronal properties. RESULTS The firing response gain in all three types of principal neurons, particularly in CA3 PCs, was markedly multiplied following pilocarpine-SE. Analyses of persistent changes in active and passive properties of CA3 PCs suggested that this increase is multifactorial in origin, the major factors being a reduction in amplitude of the slow afterhyperpolarization and an increase in the fraction of bursting neurons. SIGNIFICANCE Here we show that pilocarpine-SE causes multiplication of the firing response gain in the three principal neurons in the hippocampal trisynaptic pathway. This alteration undoubtedly would contribute to hippocampal hyperexcitability in SE-induced TLE.
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Affiliation(s)
- Idit Tamir
- Department of Medical Neurobiology, IMRIC, Hebrew University-Hadassah School of Medicine, Jerusalem 91120, Israel.
| | - Moshe Daninos
- Department of Medical Neurobiology, IMRIC, Hebrew University-Hadassah School of Medicine, Jerusalem 91120, Israel
| | - Yoel Yaari
- Department of Medical Neurobiology, IMRIC, Hebrew University-Hadassah School of Medicine, Jerusalem 91120, Israel
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18
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Control of in vivo ictogenesis via endogenous synaptic pathways. Sci Rep 2017; 7:1311. [PMID: 28465556 PMCID: PMC5431002 DOI: 10.1038/s41598-017-01450-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 03/29/2017] [Indexed: 01/13/2023] Open
Abstract
The random nature of seizures poses difficult challenges for epilepsy research. There is great need for a reliable method to control the pathway to seizure onset, which would allow investigation of the mechanisms of ictogenesis and optimization of treatments. Our hypothesis is that increased random afferent synaptic activity (i.e. synaptic noise) within the epileptic focus is one endogenous method of ictogenesis. Building upon previous theoretical and in vitro work showing that synaptic noise can induce seizures, we developed a novel in vivo model of ictogenesis. By increasing the excitability of afferent connections to the hippocampus, we control the risk of temporal lobe seizures during a specific time period. The afferent synaptic activity in the hippocampus was modulated by focal microinjections of potassium chloride into the nucleus reuniens, during which the risk of seizure occurrence increased substantially. The induced seizures were qualitatively and quantitatively indistinguishable from spontaneous ones. This model thus allows direct control of the temporal lobe seizure threshold via endogenous pathways, providing a novel tool in which to investigate the mechanisms and biomarkers of ictogenesis, test for seizure threshold, and rapidly tune antiseizure treatments.
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Rao G, Mashkouri S, Aum D, Marcet P, Borlongan CV. Contemplating stem cell therapy for epilepsy-induced neuropsychiatric symptoms. Neuropsychiatr Dis Treat 2017; 13:585-596. [PMID: 28260906 PMCID: PMC5328607 DOI: 10.2147/ndt.s114786] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Epilepsy is a debilitating disease that impacts millions of people worldwide. While unprovoked seizures characterize its cardinal symptom, an important aspect of epilepsy that remains to be addressed is the neuropsychiatric component. It has been documented for millennia in paintings and literature that those with epilepsy can suffer from bouts of aggression, depression, and other psychiatric ailments. Current treatments for epilepsy include the use of antiepileptic drugs and surgical resection. Antiepileptic drugs reduce the overall firing of the brain to mitigate the rate of seizure occurrence. Surgery aims to remove a portion of the brain that is suspected to be the source of aberrant firing that leads to seizures. Both options treat the seizure-generating neurological aspect of epilepsy, but fail to directly address the neuropsychiatric components. A promising new treatment for epilepsy is the use of stem cells to treat both the biological and psychiatric components. Stem cell therapy has been shown efficacious in treating experimental models of neurological disorders, including Parkinson's disease, and neuropsychiatric diseases, such as depression. Additional research is necessary to see if stem cells can treat both neurological and neuropsychiatric aspects of epilepsy. Currently, there is no animal model that recapitulates all the clinical hallmarks of epilepsy. This could be due to difficulty in characterizing the neuropsychiatric component of the disease. In advancing stem cell therapy for treating epilepsy, experimental testing of the safety and efficacy of allogeneic and autologous transplantation will require the optimization of cell dosage, delivery, and timing of transplantation in a clinically relevant model of epilepsy with both neurological and neuropsychiatric symptoms of the disease as the primary outcome measures.
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Affiliation(s)
- Gautam Rao
- Department of Neurosurgery and Brain Repair, Center of Excellence for Aging and Brain Repair, University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | - Sherwin Mashkouri
- Department of Neurosurgery and Brain Repair, Center of Excellence for Aging and Brain Repair, University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | - David Aum
- Department of Neurosurgery and Brain Repair, Center of Excellence for Aging and Brain Repair, University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | - Paul Marcet
- Department of Neurosurgery and Brain Repair, Center of Excellence for Aging and Brain Repair, University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | - Cesar V Borlongan
- Department of Neurosurgery and Brain Repair, Center of Excellence for Aging and Brain Repair, University of South Florida Morsani College of Medicine, Tampa, FL, USA
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Demchenko IT, Zhilyaev SY, Moskvin AN, Krivchenko AI, Piantadosi CA, Allen BW. Antiepileptic drugs prevent seizures in hyperbaric oxygen: A novel model of epileptiform activity. Brain Res 2017; 1657:347-354. [DOI: 10.1016/j.brainres.2016.12.032] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 12/29/2016] [Accepted: 12/31/2016] [Indexed: 11/25/2022]
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21
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Khoshkhoo S, Vogt D, Sohal VS. Dynamic, Cell-Type-Specific Roles for GABAergic Interneurons in a Mouse Model of Optogenetically Inducible Seizures. Neuron 2016; 93:291-298. [PMID: 28041880 DOI: 10.1016/j.neuron.2016.11.043] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 08/05/2016] [Accepted: 11/16/2016] [Indexed: 01/19/2023]
Abstract
GABAergic interneurons play critical roles in seizures, but it remains unknown whether these vary across interneuron subtypes or evolve during a seizure. This uncertainty stems from the unpredictable timing of seizures in most models, which limits neuronal imaging or manipulations around the seizure onset. Here, we describe a mouse model for optogenetic seizure induction. Combining this with calcium imaging, we find that seizure onset rapidly recruits parvalbumin (PV), somatostatin (SOM), and vasoactive intestinal peptitde (VIP)-expressing interneurons, whereas excitatory neurons are recruited several seconds later. Optogenetically inhibiting VIP interneurons consistently increased seizure threshold and reduced seizure duration. Inhibiting PV+ and SOM+ interneurons had mixed effects on seizure initiation but consistently reduced seizure duration. Thus, while their roles may evolve during seizures, PV+ and SOM+ interneurons ultimately help maintain ongoing seizures. These results show how an optogenetically induced seizure model can be leveraged to pinpoint a new target for seizure control: VIP interneurons. VIDEO ABSTRACT.
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Affiliation(s)
- Sattar Khoshkhoo
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Weil Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Sloan Swartz Center for Theoretical Neurobiology, University of California, San Francisco, San Francisco, CA 94143-0444, USA
| | - Daniel Vogt
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Weil Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94143-0444, USA
| | - Vikaas S Sohal
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Weil Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94143-0444, USA; Sloan Swartz Center for Theoretical Neurobiology, University of California, San Francisco, San Francisco, CA 94143-0444, USA.
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The use of cannabis as an antiepileptic treatment in Mexico: A review, bioethical analysis, discussion and position of the Hospital General de México Epilepsy Clinic. REVISTA MÉDICA DEL HOSPITAL GENERAL DE MÉXICO 2016. [DOI: 10.1016/j.hgmx.2016.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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23
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Vanleer AC, Blanco JA, Wagenaar JB, Viventi J, Contreras D, Litt B. Millimeter-scale epileptiform spike propagation patterns and their relationship to seizures. J Neural Eng 2016; 13:026015. [PMID: 26859260 DOI: 10.1088/1741-2560/13/2/026015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Current mapping of epileptic networks in patients prior to epilepsy surgery utilizes electrode arrays with sparse spatial sampling (∼1.0 cm inter-electrode spacing). Recent research demonstrates that sub-millimeter, cortical-column-scale domains have a role in seizure generation that may be clinically significant. We use high-resolution, active, flexible surface electrode arrays with 500 μm inter-electrode spacing to explore epileptiform local field potential (LFP) spike propagation patterns in two dimensions recorded from subdural micro-electrocorticographic signals in vivo in cat. In this study, we aimed to develop methods to quantitatively characterize the spatiotemporal dynamics of epileptiform activity at high-resolution. APPROACH We topically administered a GABA-antagonist, picrotoxin, to induce acute neocortical epileptiform activity leading up to discrete electrographic seizures. We extracted features from LFP spikes to characterize spatiotemporal patterns in these events. We then tested the hypothesis that two-dimensional spike patterns during seizures were different from those between seizures. MAIN RESULTS We showed that spatially correlated events can be used to distinguish ictal versus interictal spikes. SIGNIFICANCE We conclude that sub-millimeter-scale spatiotemporal spike patterns reveal network dynamics that are invisible to standard clinical recordings and contain information related to seizure-state.
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Affiliation(s)
- Ann C Vanleer
- Department of Electrical and Computer Engineering, United States Naval Academy, Annapolis, MD, USA
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24
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Abstract
Cannabis has been used for centuries to treat seizures. Recent anecdotal reports, accumulating animal model data, and mechanistic insights have raised interest in cannabis-based antiepileptic therapies. In this study, we review current understanding of the endocannabinoid system, characterize the pro- and anticonvulsive effects of cannabinoids [e.g., Δ9-tetrahydrocannabinol and cannabidiol (CBD)], and highlight scientific evidence from pre-clinical and clinical trials of cannabinoids in epilepsy. These studies suggest that CBD avoids the psychoactive effects of the endocannabinoid system to provide a well-tolerated, promising therapeutic for the treatment of seizures, while whole-plant cannabis can both contribute to and reduce seizures. Finally, we discuss results from a new multicenter, open-label study using CBD in a population with treatment-resistant epilepsy. In all, we seek to evaluate our current understanding of cannabinoids in epilepsy and guide future basic science and clinical studies.
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Affiliation(s)
- Evan C Rosenberg
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY, 10016, USA
| | - Richard W Tsien
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY, 10016, USA
| | - Benjamin J Whalley
- School of Pharmacy, The University of Reading, Whiteknights, Reading, RG6 6AP, UK
| | - Orrin Devinsky
- Department of Neurology, Comprehensive Epilepsy Center, New York University School of Medicine, New York, NY, 10016, UK.
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25
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Immediate Epileptogenesis after Kainate-Induced Status Epilepticus in C57BL/6J Mice: Evidence from Long Term Continuous Video-EEG Telemetry. PLoS One 2015; 10:e0131705. [PMID: 26161754 PMCID: PMC4498886 DOI: 10.1371/journal.pone.0131705] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 06/04/2015] [Indexed: 11/19/2022] Open
Abstract
The C57BL/6J mouse as a model of seizure/epilepsy is challenging due to high mortality and huge variability in response to kainate. We have recently demonstrated that repeated administration of a low dose of kainate by intraperitoneal route can induce severe status epilepticus (SE) with 94% survival rate. In the present study, based on continuous video-EEG recording for 4-18 weeks from epidurally implanted electrodes on the cortex, we demonstrate that this method also induces immediate epileptogenesis (<1-5 days post-SE). This finding was based on identification of two types of spontaneous recurrent seizures; behavioral convulsive seizures (CS) and electrographic nonconvulsive seizures (NCS). The identification of the spontaneous CS, stage 3-5 types, was based on the behaviors (video) that were associated with the EEG characteristics (stage 3-5 epileptiform spikes), the power spectrum, and the activity counts. The electrographic NCS identification was based on the stage 1-2 epileptiform spike clusters on the EEG and their associated power spectrum. Severe SE induced immediate epileptogenesis in all the mice. The maximum numbers of spontaneous CS were observed during the first 4-6 weeks of the SE and they decreased thereafter. Mild SE also induced immediate epileptogenesis in some mice but the CS were less frequent. In both the severe and the mild SE groups, the spontaneous electrographic NCS persisted throughout the 18 weeks observation period, and therefore this could serve as a chronic model for complex seizures. However, unlike rat kainate models, the C57BL/6J mouse kainate model is a unique regressive CS model of epilepsy. Further studies are required to understand the mechanism of recovery from spontaneous CS in this model, which could reveal novel therapeutic targets for epilepsy.
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26
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Grone BP, Baraban SC. Animal models in epilepsy research: legacies and new directions. Nat Neurosci 2015; 18:339-43. [PMID: 25710835 DOI: 10.1038/nn.3934] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/21/2014] [Indexed: 12/16/2022]
Abstract
Human epilepsies encompass a wide variety of clinical, behavioral and electrical manifestations. Correspondingly, studies of this disease in nonhuman animals have brought forward an equally wide array of animal models; that is, species and acute or chronic seizure induction protocols. Epilepsy research has a long history of comparative anatomical and physiological studies on a range of mostly mammalian species. Nonetheless, a relatively limited number of rodent models have emerged as the primary choices for most investigations. In many cases, these animal models are selected on the basis of convenience or tradition, although technical or experimental rationale does, and should, factor into these decisions. More complex mammalian brains and genetic model organisms including zebrafish have been studied less, but offer substantial advantages that are becoming widely recognized.
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Affiliation(s)
- Brian P Grone
- Department of Neurological Surgery, University of California, San Francisco, California, USA
| | - Scott C Baraban
- Department of Neurological Surgery, University of California, San Francisco, California, USA
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27
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Cao Q, Wang W, Gu J, Jiang G, Wang K, Xu Z, Li J, Chen G, Wang X. Elevated Expression of Acid-Sensing Ion Channel 3 Inhibits Epilepsy via Activation of Interneurons. Mol Neurobiol 2014; 53:485-498. [PMID: 25476599 DOI: 10.1007/s12035-014-9014-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 11/18/2014] [Indexed: 12/21/2022]
Abstract
Recent studies have indicated that acid-sensing ion channels may play a significant role in the termination of epilepsy. In particular, acid-sensing ion channel 3 (ASIC3) is expressed in the central nervous system and is most sensitive to extracellular pH. However, whether ASIC3 plays a role in epilepsy is unknown. In this study, qRT-PCR, Western blot, immunohistochemistry, double immunofluorescence labeling, and slice recordings were used. We first detected elevated ASIC3 expression patterns in the brains of temporal lobe epilepsy patients and epileptic rats. ASIC3 was expressed in neurons and glia in both humans and in an experimental model of epilepsy, and ASIC3 was colocalized with inhibitory GABAergic interneurons. By blocking ASIC3 with its antagonist APETx2, we observed that injected APETx2 shortened the latency to seizure and increased the incidence of generalized tonic clonic seizure compared to the control group in models of both pilocarpine- and pentylenetetrazole (PTZ)-induced seizures. Additionally, blocking ASIC3 significantly decreased the frequency of action potential (AP) firing in interneurons. Moreover, APETx2 significantly reduced the amplitudes and frequencies of miniature inhibitory postsynaptic currents (mIPSCs) while showed no differences with the APETx2 + bicuculline group and the bicuculline group. These findings suggest that elevated levels of ASIC3 may serve as an anti-epileptic mechanism via postsynaptic mechanisms in interneurons. It could represent a novel therapeutic strategy for epilepsy treatment.
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Affiliation(s)
- Qingqing Cao
- Department of Neurology, The First Affiliated Hospital, Chongqing Medical University, 1Youyi Rd, Chongqing, 400016, China.,Department of Neurology, The People's Hospital of Bishan District, 82 Xinsheng Road, Chongqing, 402760, China
| | - Wei Wang
- Department of Neurology, The First Affiliated Hospital, Chongqing Medical University, 1Youyi Rd, Chongqing, 400016, China
| | - Juan Gu
- Department of Neurology, The First Affiliated Hospital, Chongqing Medical University, 1Youyi Rd, Chongqing, 400016, China
| | - Guohui Jiang
- Department of Neurology, Affiliated Hospital of North Sichuan Medical College, 63 Wenhua Road, Nanchong, 637000, China
| | - Kewei Wang
- Department of Pharmacology, Peking University, 5 Summer Palace road, Beijing, 100871, China
| | - Zucai Xu
- Department of Neurology, The First Affiliated Hospital, Chongqing Medical University, 1Youyi Rd, Chongqing, 400016, China
| | - Jie Li
- Department of Neurology, The First Affiliated Hospital, Chongqing Medical University, 1Youyi Rd, Chongqing, 400016, China
| | - Guojun Chen
- Department of Neurology, The First Affiliated Hospital, Chongqing Medical University, 1Youyi Rd, Chongqing, 400016, China.
| | - Xuefeng Wang
- Department of Neurology, The First Affiliated Hospital, Chongqing Medical University, 1Youyi Rd, Chongqing, 400016, China. .,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, China.
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28
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Zhang Z, Liao W, Bernhardt B, Wang Z, Sun K, Yang F, Liu Y, Lu G. Brain iron redistribution in mesial temporal lobe epilepsy: a susceptibility-weighted magnetic resonance imaging study. BMC Neurosci 2014; 15:117. [PMID: 25413842 PMCID: PMC4243317 DOI: 10.1186/s12868-014-0117-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 10/07/2014] [Indexed: 11/15/2022] Open
Abstract
Background The roles of iron in epilepsy and its pathophysiological significance are poorly understood, especially whether iron levels are abnormal in subcortcal structures. This study aims to demonstrate whole-brain iron alterations and its clinical relevancies in mesial temporal lobe epilepsy (mTLE) in vivo, using susceptibility-weighted magnetic resonance imaging (SWI). Methods We studied 62 patients with mTLE and 62 healthy controls. Brain iron concentration was quantified using SWI phase values. Voxel-wise analysis was carried out to compare iron levels between mTLE and controls, and to assess the relationship between altered iron concentration and clinical parameters in mTLE. Results Patients with mTLE showed decreases of iron levels in the subcortical structures such as substantia nigra, red nucleus, and basal ganglia. Conversely, iron levels were decreased in the cortex. Subcortical iron levels were negatively correlated to those in the cortex. Moreover, cortical and basal ganglia iron levels were related to clinical variables including epilepsy duration, age at seizures onset, and histories of precipitating factors. Conclusions Our SWI findings suggest a redistribution of iron between subcortical and cortical structures in mTLE. The degree of redistribution is affected by both progression of epilepsy and precipitating factors. Investigation on brain iron redistribution offers new insights into the pathogenesis of mTLE, and may be a potential biomarker for monitoring the clinical progression of epilepsy. Electronic supplementary material The online version of this article (doi:10.1186/s12868-014-0117-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhiqiang Zhang
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, 305# Eastern Zhongshan Rd, Nanjing, 210002, China.
| | - Wei Liao
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, 305# Eastern Zhongshan Rd, Nanjing, 210002, China. .,Center for Cognition and Brain Disorders, Affiliated Hospital of Hangzhou Normal University, Hangzhou, 310015, China.
| | - Boris Bernhardt
- Department of Social Neuroscience, Max Planck Institute for Human Cognitive and Brain Science, Leipzig, Germany.
| | - Zhengge Wang
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, 305# Eastern Zhongshan Rd, Nanjing, 210002, China.
| | - Kangjian Sun
- Department of Neurosurgery, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China.
| | - Fang Yang
- Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China.
| | - Yijun Liu
- Department of Psychiatry and Neuroscience, University of Florida, Gainesville, Fl, USA.
| | - Guangming Lu
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, 305# Eastern Zhongshan Rd, Nanjing, 210002, China.
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29
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Fu Q, Sun Z, Zhang J, Gao N, Qi F, Che F, Ma G. Diazoxide preconditioning antagonizes cytotoxicity induced by epileptic seizures. Neural Regen Res 2014; 8:1000-6. [PMID: 25206393 PMCID: PMC4145886 DOI: 10.3969/j.issn.1673-5374.2013.11.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 02/05/2013] [Indexed: 01/15/2023] Open
Abstract
Diazoxide, an activator of mitochondrial ATP-sensitive potassium channels, can protect neurons and astrocytes against oxidative stress and apoptosis. In this study, we established a cellular model of epilepsy by culturing hippocampal neurons in magnesium-free medium, and used this to investigate effects of diazoxide preconditioning on the expression of inwardly rectifying potassium channel (Kir) subunits of the ATP-sensitive potassium. We found that neuronal viability was significantly reduced in the epileptic cells, whereas it was enhanced by diazoxide preconditioning. Double immunofluorescence and western blot showed a significant increase in the expression of Kir6.1 and Kir6.2 in epileptic cells, especially at 72 hours after seizures. Diazoxide pretreatment completely reversed this effect at 24 hours after seizures. In addition, Kir6.1 expression was significantly upregulated compared with Kir6.2 in hippocampal neurons after seizures. These findings indicate that diazoxide pretreatment may counteract epileptiform discharge-induced cytotoxicity by suppressing the expression of Kir subunits.
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Affiliation(s)
- Qingxi Fu
- Department of Neurology, Linyi People's Hospital, Linyi 276003, Shandong Province, China
| | - Zhiqing Sun
- Department of Neurology, Linyi People's Hospital, Linyi 276003, Shandong Province, China
| | - Jinling Zhang
- Department of Neurology, Linyi People's Hospital, Linyi 276003, Shandong Province, China
| | - Naiyong Gao
- Department of Neurology, Linyi People's Hospital, Linyi 276003, Shandong Province, China
| | - Faying Qi
- Department of Neurology, Linyi People's Hospital, Linyi 276003, Shandong Province, China
| | - Fengyuan Che
- Department of Neurology, Linyi People's Hospital, Linyi 276003, Shandong Province, China
| | - Guozhao Ma
- Department of Neurology, Shandong Provincial Hospital, Shandong University, Jinan 250021, Shandong Province, China
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30
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Anti-epileptic effect of Ganoderma lucidum polysaccharides by inhibition of intracellular calcium accumulation and stimulation of expression of CaMKII α in epileptic hippocampal neurons. PLoS One 2014; 9:e102161. [PMID: 25010576 PMCID: PMC4092074 DOI: 10.1371/journal.pone.0102161] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 06/15/2014] [Indexed: 11/19/2022] Open
Abstract
Purpose To investigate the mechanism of the anti-epileptic effect of Ganoderma lucidum polysaccharides (GLP), the changes of intracellular calcium and CaMK II α expression in a model of epileptic neurons were investigated. Method Primary hippocampal neurons were divided into: 1) Control group, neurons were cultured with Neurobasal medium, for 3 hours; 2) Model group I: neurons were incubated with Mg2+ free medium for 3 hours; 3) Model group II: neurons were incubated with Mg2+ free medium for 3 hours then cultured with the normal medium for a further 3 hours; 4) GLP group I: neurons were incubated with Mg2+ free medium containing GLP (0.375 mg/ml) for 3 hours; 5) GLP group II: neurons were incubated with Mg2+ free medium for 3 hours then cultured with a normal culture medium containing GLP for a further 3 hours. The CaMK II α protein expression was assessed by Western-blot. Ca2+ turnover in neurons was assessed using Fluo-3/AM which was added into the replacement medium and Ca2+ turnover was observed under a laser scanning confocal microscope. Results The CaMK II α expression in the model groups was less than in the control groups, however, in the GLP groups, it was higher than that observed in the model group. Ca2+ fluorescence intensity in GLP group I was significantly lower than that in model group I after 30 seconds, while in GLP group II, it was reduced significantly compared to model group II after 5 minutes. Conclusion GLP may inhibit calcium overload and promote CaMK II α expression to protect epileptic neurons.
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31
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Jirsa VK, Stacey WC, Quilichini PP, Ivanov AI, Bernard C. On the nature of seizure dynamics. ACTA ACUST UNITED AC 2014; 137:2210-30. [PMID: 24919973 DOI: 10.1093/brain/awu133] [Citation(s) in RCA: 395] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Seizures can occur spontaneously and in a recurrent manner, which defines epilepsy; or they can be induced in a normal brain under a variety of conditions in most neuronal networks and species from flies to humans. Such universality raises the possibility that invariant properties exist that characterize seizures under different physiological and pathological conditions. Here, we analysed seizure dynamics mathematically and established a taxonomy of seizures based on first principles. For the predominant seizure class we developed a generic model called Epileptor. As an experimental model system, we used ictal-like discharges induced in vitro in mouse hippocampi. We show that only five state variables linked by integral-differential equations are sufficient to describe the onset, time course and offset of ictal-like discharges as well as their recurrence. Two state variables are responsible for generating rapid discharges (fast time scale), two for spike and wave events (intermediate time scale) and one for the control of time course, including the alternation between 'normal' and ictal periods (slow time scale). We propose that normal and ictal activities coexist: a separatrix acts as a barrier (or seizure threshold) between these states. Seizure onset is reached upon the collision of normal brain trajectories with the separatrix. We show theoretically and experimentally how a system can be pushed toward seizure under a wide variety of conditions. Within our experimental model, the onset and offset of ictal-like discharges are well-defined mathematical events: a saddle-node and homoclinic bifurcation, respectively. These bifurcations necessitate a baseline shift at onset and a logarithmic scaling of interspike intervals at offset. These predictions were not only confirmed in our in vitro experiments, but also for focal seizures recorded in different syndromes, brain regions and species (humans and zebrafish). Finally, we identified several possible biophysical parameters contributing to the five state variables in our model system. We show that these parameters apply to specific experimental conditions and propose that there exists a wide array of possible biophysical mechanisms for seizure genesis, while preserving central invariant properties. Epileptor and the seizure taxonomy will guide future modeling and translational research by identifying universal rules governing the initiation and termination of seizures and predicting the conditions necessary for those transitions.
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Affiliation(s)
- Viktor K Jirsa
- 1 Aix Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France2 Inserm, UMR_S 1106, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - William C Stacey
- 3 Department of Neurology, Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Pascale P Quilichini
- 1 Aix Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France2 Inserm, UMR_S 1106, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Anton I Ivanov
- 1 Aix Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France2 Inserm, UMR_S 1106, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Christophe Bernard
- 1 Aix Marseille Université, Institut de Neurosciences des Systèmes, Marseille, France2 Inserm, UMR_S 1106, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
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Advantages of repeated low dose against single high dose of kainate in C57BL/6J mouse model of status epilepticus: behavioral and electroencephalographic studies. PLoS One 2014; 9:e96622. [PMID: 24802808 PMCID: PMC4011859 DOI: 10.1371/journal.pone.0096622] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 04/09/2014] [Indexed: 11/19/2022] Open
Abstract
A refined kainate (KA) C57BL/6J mouse model of status epilepticus (SE) using a repeated low dose (RLD) of KA (5 mg/kg, intraperitoneal; at 30 min intervals) was compared with the established single high dose (SHD) of KA (20 mg/kg, intraperitoneal) model. In the RLD group, increased duration of convulsive motor seizures (CMS, Racine scale stage ≥3) with a significant reduction in mortality from 21% to 6% and decreased variability in seizure severity between animals/batches were observed when compared to the SHD group. There was a significant increase in the percentage of animals that reached stage-5 seizures (65% versus 96%) in the RLD group. Integrated real-time video-EEG analysis of both groups, using NeuroScore software, revealed stage-specific spikes and power spectral density characteristics. When the seizures progressed from non-convulsive seizures (NCS, stage 1-2) to CMS (stage 3-5), the delta power decreased which was followed by an increase in gamma and beta power. A transient increase in alpha and sigma power marked the transition from NCS to CMS with characteristic 'high frequency trigger' spikes on the EEG, which had no behavioral expression. During SE the spike rate was higher in the RLD group than in the SHD group. Overall these results confirm that RLD of KA is a more robust and consistent mouse model of SE than the SHD of KA mouse model.
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33
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Harward SC, McNamara JO. Aligning animal models with clinical epilepsy: where to begin? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 813:243-51. [PMID: 25012381 DOI: 10.1007/978-94-017-8914-1_19] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Treatment of the epilepsies have benefitted immensely from study of animal models, most notably in the development of diverse anti-seizure medications in current clinical use. However, available drugs provide only symptomatic relief from seizures and are often ineffective. As a result, a critical need remains for developing improved symptomatic or disease-modifying therapies - or ideally, preventive therapies. Animal models will undoubtedly play a central role in such efforts. To ensure success moving forward, a critical question arises, namely "How does one make laboratory models relevant to our clinical understanding and treatment?" Our answer to this question: It all begins with a detailed understanding of the clinical phenotype one seeks to model. To make our case, we point to two examples - Fragile X syndrome and status epilepticus-induced mesial temporal lobe epilepsy - and examine how development of animal models for these distinct syndromes is based upon observations by astute clinicians and systematic study of the disorder. We conclude that the continuous and effective interaction of skilled clinicians and bench scientists is critical to the optimal design and study of animal models to facilitate insight into the nature of human disorders and enhance likelihood of improved therapies.
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Affiliation(s)
- Stephen C Harward
- Department of Neurobiology, Duke University Medical Center, Durham, NC, 27710, USA,
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34
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Hubbard JA, Hsu MS, Fiacco TA, Binder DK. Glial cell changes in epilepsy: Overview of the clinical problem and therapeutic opportunities. Neurochem Int 2013; 63:638-51. [DOI: 10.1016/j.neuint.2013.01.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 01/14/2013] [Accepted: 01/18/2013] [Indexed: 12/20/2022]
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Lévesque M, Avoli M. The kainic acid model of temporal lobe epilepsy. Neurosci Biobehav Rev 2013; 37:2887-99. [PMID: 24184743 DOI: 10.1016/j.neubiorev.2013.10.011] [Citation(s) in RCA: 384] [Impact Index Per Article: 34.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 10/16/2013] [Accepted: 10/22/2013] [Indexed: 01/01/2023]
Abstract
The kainic acid model of temporal lobe epilepsy has greatly contributed to the understanding of the molecular, cellular and pharmacological mechanisms underlying epileptogenesis and ictogenesis. This model presents with neuropathological and electroencephalographic features that are seen in patients with temporal lobe epilepsy. It is also characterized by a latent period that follows the initial precipitating injury (i.e., status epilepticus) until the appearance of recurrent seizures, as observed in the human condition. Finally, the kainic acid model can be reproduced in a variety of species using either systemic, intrahippocampal or intra-amygdaloid administrations. In this review, we describe the various methodological procedures and evaluate their differences with respect to the behavioral, electroencephalographic and neuropathological correlates. In addition, we compare the kainic acid model with other animal models of temporal lobe epilepsy such as the pilocarpine and the kindling model. We conclude that the kainic acid model is a reliable tool for understanding temporal lobe epilepsy, provided that the differences existing between methodological procedures are taken into account.
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Affiliation(s)
- Maxime Lévesque
- Montreal Neurological Institute and Departments of Neurology & Neurosurgery, and of Physiology, McGill University, Montréal, QC, Canada H3A 2B4
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36
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Tsytsarev V, Rao B, Maslov KI, Li L, Wang LV. Photoacoustic and optical coherence tomography of epilepsy with high temporal and spatial resolution and dual optical contrasts. J Neurosci Methods 2013; 216:142-5. [PMID: 23603664 DOI: 10.1016/j.jneumeth.2013.04.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/01/2013] [Accepted: 04/04/2013] [Indexed: 01/26/2023]
Abstract
Epilepsy mapping with high spatial and temporal resolution has great significance for both fundamental research on epileptic neurons and the clinical management of epilepsy. In this communication, we demonstrate for the first time in vivo epilepsy mapping with high spatial and temporal resolution and dual optical contrasts in an animal model. Through the variations of a depthresolved optical coherence tomography signal with optical scattering contrast, we observed that epileptic neuron activities modulated the optical refractive index of epileptic neurons and their surrounding tissue. Simultaneously, through neurovasculature coupling mechanisms and optical absorption contrast, we used photoacoustic signals to document the hemodynamic changes of the microvasculature surrounding the epileptic neurons. The epilepsy mapping results were confirmed by a simultaneously recorded electroencephalogram signal during epileptic seizure. Our new epilepsy mapping tool, with high temporal and spatial resolution and dual optical contrasts, may find many applications, such as drug development and epilepsy surgery.
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Affiliation(s)
- Vassiliy Tsytsarev
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
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Optogenetically induced seizure and the longitudinal hippocampal network dynamics. PLoS One 2013; 8:e60928. [PMID: 23593349 PMCID: PMC3622611 DOI: 10.1371/journal.pone.0060928] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Accepted: 03/04/2013] [Indexed: 11/19/2022] Open
Abstract
Epileptic seizure is a paroxysmal and self-limited phenomenon characterized by abnormal hypersynchrony of a large population of neurons. However, our current understanding of seizure dynamics is still limited. Here we propose a novel in vivo model of seizure-like afterdischarges using optogenetics, and report on investigation of directional network dynamics during seizure along the septo-temporal (ST) axis of hippocampus. Repetitive pulse photostimulation was applied to the rodent hippocampus, in which channelrhodopsin-2 (ChR2) was expressed, under simultaneous recording of local field potentials (LFPs). Seizure-like afterdischarges were successfully induced after the stimulation in both W-TChR2V4 transgenic (ChR2V-TG) rats and in wild type rats transfected with adeno-associated virus (AAV) vectors carrying ChR2. Pulse frequency at 10 and 20 Hz, and a 0.05 duty ratio were optimal for afterdischarge induction. Immunohistochemical c-Fos staining after a single induced afterdischarge confirmed neuronal activation of the entire hippocampus. LFPs were recorded during seizure-like afterdischarges with a multi-contact array electrode inserted along the ST axis of hippocampus. Granger causality analysis of the LFPs showed a bidirectional but asymmetric increase in signal flow along the ST direction. State space presentation of the causality and coherence revealed three discrete states of the seizure-like afterdischarge phenomenon: 1) resting state; 2) afterdischarge initiation with moderate coherence and dominant septal-to-temporal causality; and 3) afterdischarge termination with increased coherence and dominant temporal-to-septal causality. A novel in vivo model of seizure-like afterdischarge was developed using optogenetics, which was advantageous in its reproducibility and artifact-free electrophysiological observations. Our results provide additional evidence for the potential role of hippocampal septo-temporal interactions in seizure dynamics in vivo. Bidirectional networks work hierarchically along the ST hippocampus in the genesis and termination of epileptic seizures.
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Mourão CBF, Heghinian MD, Barbosa EA, Marí F, Bloch C, Restano-Cassulini R, Possani LD, Schwartz EF. Characterization of a Novel Peptide Toxin from Acanthoscurria paulensis Spider Venom: A Distinct Cysteine Assignment to the HWTX-II Family. Biochemistry 2013; 52:2440-52. [DOI: 10.1021/bi4000035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Caroline B. F. Mourão
- Laboratório de Toxinologia,
Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, DF
70910-900, Brazil
| | - Mari D. Heghinian
- Department
of Chemistry and
Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Eder A. Barbosa
- EMBRAPA Recursos Genéticos e Biotecnologia, Brasília, DF,
Brazil
| | - Frank Marí
- Department
of Chemistry and
Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Carlos Bloch
- EMBRAPA Recursos Genéticos e Biotecnologia, Brasília, DF,
Brazil
| | - Rita Restano-Cassulini
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca, 62210
Morelos, Mexico
| | - Lourival D. Possani
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca, 62210
Morelos, Mexico
| | - Elisabeth F. Schwartz
- Laboratório de Toxinologia,
Departamento de Ciências Fisiológicas, Universidade de Brasília, Brasília, DF
70910-900, Brazil
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