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West PJ, Thomson K, Billingsley P, Pruess T, Rueda C, Saunders GW, Smith MD, Metcalf CS, Wilcox KS. Spontaneous recurrent seizures in an intra-amygdala kainate microinjection model of temporal lobe epilepsy are differentially sensitive to antiseizure drugs. Exp Neurol 2021; 349:113954. [PMID: 34922908 PMCID: PMC8815304 DOI: 10.1016/j.expneurol.2021.113954] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 10/14/2021] [Accepted: 12/13/2021] [Indexed: 12/15/2022]
Abstract
The discovery and development of novel antiseizure drugs (ASDs) that are effective in controlling pharmacoresistant spontaneous recurrent seizures (SRSs) continues to represent a significant unmet clinical need. The Epilepsy Therapy Screening Program (ETSP) has undertaken efforts to address this need by adopting animal models that represent the salient features of human pharmacoresistant epilepsy and employing these models for preclinical testing of investigational ASDs. One such model that has garnered increased interest in recent years is the mouse variant of the Intra-Amygdala Kainate (IAK) microinjection model of mesial temporal lobe epilepsy (MTLE). In establishing a version of this model, several methodological variables were evaluated for their effect(s) on pertinent quantitative endpoints. Although administration of a benzodiazepine 40 min after kainate (KA) induced status epilepticus (SE) is commonly used to improve survival, data presented here demonstrates similar outcomes (mortality, hippocampal damage, latency periods, and 90-day SRS natural history) between mice given midazolam and those that were not. Using a version of this model that did not interrupt SE with a benzodiazepine, a 90-day natural history study was performed and survival, latency periods, SRS frequencies and durations, and SRS clustering data were quantified. Finally, an important step towards model adoption is to assess the sensitivities or resistances of SRSs to a panel of approved and clinically used ASDs. Accordingly, the following ASDs were evaluated for their effects on SRSs in these mice: phenytoin (20 mg/kg, b.i.d.), carbamazepine (30 mg/kg, t.i.d.), valproate (240 mg/kg, t.i.d.), diazepam (4 mg/kg, b.i.d.), and phenobarbital (25 and 50 mg/kg, b. i.d.). Valproate, diazepam, and phenobarbital significantly attenuated SRS frequency relative to vehicle controls at doses devoid of observable adverse behavioral effects. Only diazepam significantly increased seizure freedom. Neither phenytoin nor carbamazepine significantly altered SRS frequency or freedom under these experimental conditions. These data demonstrate that SRSs in this IAK model of MTLE are pharmacoresistant to two representative sodium channel-inhibiting ASDs (phenytoin and carbamazepine) and partially sensitive to GABA receptor modulating ASDs (diazepam and phenobarbital) or a mixed-mechanism ASD (valproate). Accordingly, this model is being incorporated into the NINDS-funded ETSP testing platform for treatment resistant epilepsy.
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Affiliation(s)
- Peter J West
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA; Interdepartmental Neuroscience Program, University of Utah, Salt Lake City, UT 84108, USA.
| | - Kyle Thomson
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Peggy Billingsley
- Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Timothy Pruess
- Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Carlos Rueda
- Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Gerald W Saunders
- Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Misty D Smith
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA; School of Dentistry, University of Utah, Salt Lake City, UT 84108, USA
| | - Cameron S Metcalf
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA
| | - Karen S Wilcox
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA; Epilepsy Therapy Screening Program (ETSP) Contract Site, University of Utah, Salt Lake City, UT 84112, USA; Interdepartmental Neuroscience Program, University of Utah, Salt Lake City, UT 84108, USA
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Ventoso P, Pazos AJ, Blanco J, Pérez-Parallé ML, Triviño JC, Sánchez JL. Transcriptional Response in the Digestive Gland of the King Scallop ( Pecten maximus) After the Injection of Domoic Acid. Toxins (Basel) 2021; 13:toxins13050339. [PMID: 34067146 PMCID: PMC8150855 DOI: 10.3390/toxins13050339] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 05/05/2021] [Accepted: 05/05/2021] [Indexed: 01/18/2023] Open
Abstract
Some diatom species of the genus Pseudo-nitzschia produce the toxin domoic acid. The depuration rate of domoic acid in Pecten maximus is very low; for this reason, king scallops generally contain high levels of domoic acid in their tissues. A transcriptomic approach was used to identify the genes differentially expressed in the P. maximus digestive gland after the injection of domoic acid. The differential expression analysis found 535 differentially expressed genes (226 up-regulated and 309 down-regulated). Protein–protein interaction networks obtained with the up-regulated genes were enriched in gene ontology terms, such as vesicle-mediated transport, response to stress, signal transduction, immune system process, RNA metabolic process, and autophagy, while networks obtained with the down-regulated genes were enriched in gene ontology terms, such as response to stress, immune system process, ribosome biogenesis, signal transduction, and mRNA processing. Genes that code for cytochrome P450 enzymes, glutathione S-transferase theta-1, glutamine synthase, pyrroline-5-carboxylate reductase 2, and sodium- and chloride-dependent glycine transporter 1 were among the up-regulated genes. Therefore, a stress response at the level of gene expression, that could be caused by the domoic acid injection, was evidenced by the alteration of several biological, cellular, and molecular processes.
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Affiliation(s)
- Pablo Ventoso
- Departamento de Bioquímica y Biología Molecular, Instituto de Acuicultura, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; (P.V.); (M.L.P.-P.); (J.L.S.)
| | - Antonio J. Pazos
- Departamento de Bioquímica y Biología Molecular, Instituto de Acuicultura, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; (P.V.); (M.L.P.-P.); (J.L.S.)
- Correspondence:
| | - Juan Blanco
- Centro de Investigacións Mariñas, Xunta de Galicia, Pedras de Corón s/n Apdo. 13, 36620 Vilanova de Arousa, Spain;
| | - M. Luz Pérez-Parallé
- Departamento de Bioquímica y Biología Molecular, Instituto de Acuicultura, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; (P.V.); (M.L.P.-P.); (J.L.S.)
| | - Juan C. Triviño
- Sistemas Genómicos, Ronda G. Marconi 6, Paterna, 46980 Valencia, Spain;
| | - José L. Sánchez
- Departamento de Bioquímica y Biología Molecular, Instituto de Acuicultura, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; (P.V.); (M.L.P.-P.); (J.L.S.)
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Sha L, Chen T, Deng Y, Du T, Ma K, Zhu W, Shen Y, Xu Q. Hsp90 inhibitor HSP990 in very low dose upregulates EAAT2 and exerts potent antiepileptic activity. Theranostics 2020; 10:8415-8429. [PMID: 32724478 PMCID: PMC7381737 DOI: 10.7150/thno.44721] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 06/11/2020] [Indexed: 12/26/2022] Open
Abstract
Rationale: Dysfunction or reduced levels of EAAT2 have been documented in epilepsy. We previously demonstrated the antiepileptic effects of Hsp90 inhibitor 17AAG in temporal lobe epilepsy by preventing EAAT2 degradation. Because of the potential toxicities of 17AAG, this study aimed to identify an alternative Hsp90 inhibitor with better performance on Hsp90 inhibition, improved blood-brain barrier penetration and minimal toxicity. Methods: We used cell-based screening and animal models of epilepsy, including mouse models of epilepsy and Alzheimer's disease, and a cynomolgus monkey model of epilepsy, to evaluate the antiepileptic effects of new Hsp90 inhibitors. Results: In both primary cultured astrocytes and normal mice, HSP990 enhanced EAAT2 levels at a lower dose than other Hsp90 inhibitors. In epileptic mice, administration of 0.1 mg/kg HSP990 led to upregulation of EAAT2 and inhibition of spontaneous seizures. Additionally, HSP990 inhibited seizures and improved cognitive functions in the APPswe/PS1dE9 transgenic model of Alzheimer's disease. In a cynomolgus monkey model of temporal lobe epilepsy, oral administration of low-dose HSP990 completely suppressed epileptiform discharges for up to 12 months, with no sign of hepatic and renal toxicity. Conclusions: These results support further preclinical studies of HSP990 treatment for temporal lobe epilepsy.
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Affiliation(s)
- Longze Sha
- State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, 100005, China
- Neuroscience center, Chinese Academy of Medical Sciences, Beijing, 100005, China
| | - Ting Chen
- State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, 100005, China
| | - Yu Deng
- State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, 100005, China
| | - Tingfu Du
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, 650118, China
- Neuroscience center, Chinese Academy of Medical Sciences, Beijing, 100005, China
| | - Kaili Ma
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, 650118, China
- Neuroscience center, Chinese Academy of Medical Sciences, Beijing, 100005, China
| | - Wanwan Zhu
- State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, 100005, China
- Neuroscience center, Chinese Academy of Medical Sciences, Beijing, 100005, China
| | - Yan Shen
- State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, 100005, China
| | - Qi Xu
- State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, 100005, China
- Neuroscience center, Chinese Academy of Medical Sciences, Beijing, 100005, China
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Ishikawa A, Mizuno Y, Sakai K, Maki T, Tanaka R, Oda Y, Niimi K, Takahashi E. Kainic acid-induced seizures in the common marmoset. Biochem Biophys Res Commun 2020; 525:595-599. [PMID: 32115153 DOI: 10.1016/j.bbrc.2020.02.121] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 02/20/2020] [Indexed: 11/17/2022]
Abstract
Treatment of epilepsy remains difficult because patients suffer from pharmacoresistant forms of the disease and drug side-effects. Thus, there is an urgent need to identify not only new antiepileptic drug candidates but also novel epileptic animal models. Here, we characterize seizures induced with kainic acid (KA) in the common marmoset (Callithrix jacchus). Adult marmosets received 0.1, 1, or 10 mg/kg of KA subcutaneously. All animals exhibited early convulsive behavior (seizure scores of I and II on the Racine scale). Seizure scores were low at lower KA doses, but the highest dose of KA tested triggered generalized seizures (scores IV and V on the Racine scale). We next performed preliminary evaluation of the efficacy of the antiepileptic drug diazepam. This drug at 1 mg/kg (delivered subcutaneously) prevented 10 mg/kg KA-induced stage V seizures. KA administration to marmosets reliably triggers generalized seizures; therefore, the marmoset is a useful animal model in which to analyze the seizures of a nonhuman primate brain and to develop new treatments for epilepsy.
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Affiliation(s)
| | - Yuri Mizuno
- Sleep Science Laboratories, HAMRI Co. Ltd, Ibaraki, 306-0128, Japan
| | - Keita Sakai
- Sleep Science Laboratories, HAMRI Co. Ltd, Ibaraki, 306-0128, Japan
| | - Takehiro Maki
- Sleep Science Laboratories, HAMRI Co. Ltd, Ibaraki, 306-0128, Japan
| | - Ryo Tanaka
- Sleep Science Laboratories, HAMRI Co. Ltd, Ibaraki, 306-0128, Japan
| | - Yasuhiro Oda
- Sleep Science Laboratories, HAMRI Co. Ltd, Ibaraki, 306-0128, Japan
| | - Kimie Niimi
- Research Resources Division, RIKEN Center for Brain Science, Saitama, 351-0198, Japan.
| | - Eiki Takahashi
- Research Resources Division, RIKEN Center for Brain Science, Saitama, 351-0198, Japan.
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Anagnostou I, Morales T. Fatherhood diminishes the hippocampal damaging action of excitotoxic lesioning in mice. J Neuroendocrinol 2019; 31:e12783. [PMID: 31433881 DOI: 10.1111/jne.12783] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 08/01/2019] [Accepted: 08/16/2019] [Indexed: 11/29/2022]
Abstract
Parental experience imposes neuroplasticity in the hippocampus of females and males. In lactating rat dams, the hippocampus is protected against excitotoxic damage by kainic acid lesioning, although it is still unknown whether paternity can provide such protection to male rodents. To evaluate the protective effects of fatherhood against excitotoxic lesions, we paired male mice with females and co-housed them until the day of parturition (PPD0), when we randomly assigned them to two groups: (i) the pregnancy group (males housed individually overnight and injected i.c.v. with 100 ng per 1 μL of kainic acid or vehicle on PPD1) and (ii) the sire group (males housed with the dam and pups until PPD8, when injected i.c.v. after evaluation of parental behaviour). Individually housed virgin adult male mice formed the control group. Markers of neurodegeneration (NeuN, Fluoro-Jade C) and astrogliosis (glial fibrillary acidic protein) were evaluated in fixed cerebral tissue containing the dorsal CA1, CA3 and CA4 hippocampal subfields. The CA1 subfield did not suffer damage in any of the experimental groups. The sire group exhibited less neurodegeneration and astrogliosis in the CA3 and CA4 subfields compared to their respective controls, independently of the expression of parental behaviour. Western blot analysis was conducted for prolactin (PRL), PRL receptor and related intracellular pathways. Monomeric PRL was lower in the hippocampus of sires in the first week postpartum with a parallel rise of a 48-kDa dimerised isoform compared to virgin controls. The long isoform of PRL receptor did not change, and signal transducer and activator of transcription 5 (STAT5) was not detected in the hippocampus. However, a sustained rise in pAkt, a signalling molecule that participates in cell survival, was observed in the sire group. These results indicate that the hippocampus of sires housed with the dam and pups is less sensitive to neurotoxic injury, which might not be primarily regulated by PRL-STAT5-modulated mechanisms.
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Affiliation(s)
- Ilektra Anagnostou
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Teresa Morales
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
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Nikbakht F, Belali R, Rasoolijazi H, Mohammad Khanizadeh A. 2-Deoxyglucose protects hippocampal neurons against kainate-induced temporal lobe epilepsy by modulating monocyte-derived macrophages (mo-MΦ) and progranulin production in the hippocampus. Neuropeptides 2019; 76:101932. [PMID: 31227312 DOI: 10.1016/j.npep.2019.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 05/03/2019] [Accepted: 05/07/2019] [Indexed: 02/04/2023]
Abstract
Inflammation is an important factor in the pathology of epilepsy with the hallmarks of resident microglia activation and infiltration of circulating monocytes in the damaged area. In the case of recovery and tissue repair, some monocytes change to macrophages (mo-MΦ) to enhance tissue repair. 2-deoxyglucose (2DG) is an analog of glucose capable of protecting the brain, and progranulin is a neurotrophic factor produced mainly by microglia and has an inflammation modulator effect. This study attempted to evaluate if one of the neuroprotective mechanisms of 2-DG is comprised of increasing monocyte-derived macrophages (mo-MΦ) and progranulin production. Status epilepticus (SE) was induced by i.c.v. injection of kainic acid (KA).2DG (125/mg/kg/day) was administered intraperitoneally. Four days later, animals were sacrificed. Their brain sections were then stained with Cresyl violet and Fluoro-Jade B to count the number of necrotic and degenerating neurons in CA3 and Hilus of dentate gyrus of the hippocampus. Lastly, immunohistochemistry was used to detect CD11b + monocyte, macrophage cells, and Progranulin level was evaluated by Western blotting. The histological analysis showed that 2DG can reduce the number of necrotic and degenerating neurons in CA3 and Hilar areas. Following KA administration, a great number of cD11b+ cells with monocyte morphology were observed in the hippocampus. 2DG not only reduced cD11b+ monocyte cells but was able to convert them to cells with the morphology of macrophages (mo-MΦ). 2DG also caused a significant increase in progranulin level in the hippocampus. Because macrophages and microglia are the most important sources of progranulin, it appears that 2DG caused the derivation of monocytes to macrophages and these cells produced progranulin with a subsequent anti-inflammation effect. In summary, it was concluded that 2DG is neuroprotective and probably one of its neuroprotective mechanisms is by modulating monocyte-derived macrophages by progranulin production.
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Affiliation(s)
- Farnaz Nikbakht
- Cellular and Molecular Research Center and Department of Physiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Rafie Belali
- Cellular and Molecular Research Center and Department of Physiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Homa Rasoolijazi
- Department of Anatomy, Iran University of Medical Sciences, Tehran, Iran
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Tse K, Hammond D, Simpson D, Beynon RJ, Beamer E, Tymianski M, Salter MW, Sills GJ, Thippeswamy T. The impact of postsynaptic density 95 blocking peptide (Tat-NR2B9c) and an iNOS inhibitor (1400W) on proteomic profile of the hippocampus in C57BL/6J mouse model of kainate-induced epileptogenesis. J Neurosci Res 2019; 97:1378-1392. [PMID: 31090233 DOI: 10.1002/jnr.24441] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 12/22/2022]
Abstract
Antiepileptogenic agents that prevent the development of epilepsy following a brain insult remain the holy grail of epilepsy therapeutics. We have employed a label-free proteomic approach that allows quantification of large numbers of brain-expressed proteins in a single analysis in the mouse (male C57BL/6J) kainate (KA) model of epileptogenesis. In addition, we have incorporated two putative antiepileptogenic drugs, postsynaptic density protein-95 blocking peptide (PSD95BP or Tat-NR2B9c) and a highly selective inducible nitric oxide synthase inhibitor, 1400W, to give an insight into how such agents might ameliorate epileptogenesis. The test drugs were administered after the induction of status epilepticus (SE) and the animals were euthanized at 7 days, their hippocampi removed, and subjected to LC-MS/MS analysis. A total of 2,579 proteins were identified; their normalized abundance was compared between treatment groups using ANOVA, with correction for multiple testing by false discovery rate. Significantly altered proteins were subjected to gene ontology and KEGG pathway enrichment analyses. KA-induced SE was most robustly associated with an alteration in the abundance of proteins involved in neuroinflammation, including heat shock protein beta-1 (HSP27), glial fibrillary acidic protein, and CD44 antigen. Treatment with PSD95BP or 1400W moderated the abundance of several of these proteins plus that of secretogranin and Src substrate cortactin. Pathway analysis identified the glutamatergic synapse as a key target for both drugs. Our observations require validation in a larger-scale investigation, with candidate proteins explored in more detail. Nevertheless, this study has identified several mechanisms by which epilepsy might develop and several targets for novel drug development. OPEN PRACTICES: This article has been awarded Open Data. All materials and data are publicly accessible as supporting information. Learn more about the Open Practices badges from the Center for Open Science: https://osf.io/tvyxz/wiki.
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Affiliation(s)
- Karen Tse
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Dean Hammond
- Department of Molecular and Cellular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Deborah Simpson
- Centre for Proteome Research, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Robert J Beynon
- Centre for Proteome Research, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Edward Beamer
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Michael Tymianski
- Department of Physiology and Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Michael W Salter
- Department of Physiology and Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Graeme J Sills
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Thimmasettappa Thippeswamy
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
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Chiu KM, Lin TY, Lee MY, Lu CW, Wang MJ, Wang SJ. Ropivacaine Protects against Memory Impairment and Hippocampal Damage in a Rat Neurodegeneration Model. Pharmacology 2018; 102:307-315. [PMID: 30257255 DOI: 10.1159/000493145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 08/21/2018] [Indexed: 04/13/2024]
Abstract
BACKGROUND Ropivacaine, a long-acting amide local anesthetic agent, has been demonstrated to inhibit glutamatergic transmission. Glutamate neurotoxicity plays a pivotal role in the pathogenesis of brain disorders. The purpose of this study is to investigate the neuroprotective effect of ropivacaine against brain damage induced by kainic acid (KA), an analogue of glutamate. METHODS Rats were injected with ropivacaine (0.4 or 2 mg/kg, intraperitoneal) 30 min before KA treatment (15 mg/kg, intraperitoneal). KA-induced memory impairment was evaluated using the Morris water maze test. Extracellular hippocampal glutamate levels were assessed using high-performance liquid chromatography. Neuronal death was verified using Fluoro-Jade B and neutral red staining, and apoptosis was determined through terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Western blotting was conducted to assay the levels of activated (cleaved) caspase-3 and the phosphorylation of different mitogen-activated protein kinases (MAPKs). -Results: Ropivacaine pretreatment effectively prevented KA-induced memory impairment. KA-induced elevations of -glutamate release in rat hippocampi were inhibited by pretreatment with ropivacaine. Histopathological and TUNEL staining analyzes showed that ropivacaine inhibited KA-induced neuronal death and apoptosis in the hippocampal CA3 region. KA-induced caspase-3 activation and MAPKs phosphorylation in the hippocampus were also reduced by ropivacaine pretreatment. CONCLUSIONS This study -demonstrates that ropivacaine executes a protective action against KA-induced neuronal damage and apoptosis in vivo. Protective effects may be caused by glutamate level reduction, caspase-3 activation suppression, and MAPKs phosphorylation reduction. Our findings indicate that ropivacaine can benefit prevention or treatment of glutamate excitotoxicity-related neurodegenerative diseases.
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Affiliation(s)
- Kuan-Ming Chiu
- Division of Cardiovascular Surgery, Cardiovascular Center, Far-Eastern Memorial Hospital, New Taipei City, Taiwan
- Department of Nursing, Oriental Institute of Technology, New Taipei City, Taiwan
- Department of Photonics Engineering, Yuan Ze University, New Taipei City, Taiwan
| | - Tzu-Yu Lin
- Department of Anesthesiology, Far-Eastern Memorial Hospital, New Taipei City, Taiwan
- Department of Mechanical Engineering, Yuan Ze University, New Taipei City, Taiwan
| | - Ming-Yi Lee
- Division of Cardiovascular Surgery, Cardiovascular Center, Far-Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Cheng-Wei Lu
- Department of Anesthesiology, Far-Eastern Memorial Hospital, New Taipei City, Taiwan
- Department of Mechanical Engineering, Yuan Ze University, New Taipei City, Taiwan
| | - Ming-Jiuh Wang
- Department of Anesthesiology, National Taiwan University Hospital, New Taipei City, Taiwan
| | - Su-Jane Wang
- Graduate Institute of Basic Medicine, New Taipei City, Taiwan,
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan,
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Yamamoto K, Mifflin S. Inhibition of glial glutamate transporter GLT1 in the nucleus of the solitary tract attenuates baroreflex control of sympathetic nerve activity and heart rate. Physiol Rep 2018; 6:e13877. [PMID: 30230240 PMCID: PMC6144441 DOI: 10.14814/phy2.13877] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/22/2018] [Accepted: 08/31/2018] [Indexed: 02/02/2023] Open
Abstract
The astrocytic glutamate transporter (GLT1) plays an important role in the maintenance of extracellular glutamate concentration below neurotoxic levels in brain. However, the functional role of GLT1 within the nucleus of the solitary tract (NTS) in the regulation of cardiovascular function remains unclear. We examined the effect of inhibiting GLT1 in the subpostremal NTS on mean arterial pressure (MAP), renal sympathetic nerve activity (RSNA) and heart rate (HR) in anesthetized, artificially ventilated rats. It was found that dihydrokainate (DHK; inhibitor of GLT1, 5 mmol/L, 100 nL) injections into the NTS (n = 6) decreased MAP (50 ± 10 mmHg, mean ± SD), RSNA (89 ± 14%) and HR (37 ± 6 bpm). Pretreatment with kynurenate (KYN; glutamate receptor antagonist, 5 mmol/L, 30 μL) topically applied to the dorsal surface of the brainstem (n = 4) attenuated the responses to NTS injections of DHK (P < 0.01). The effect of DHK on arterial baroreflex function was examined using i.v. infusions of phenylephrine and nitroprusside. DHK reduced baroreflex response range (maximum-minimum) of RSNA by 91 ± 2% and HR by 83 ± 5% (n = 6, P < 0.001). These results indicate that inhibition of GLT1 within the NTS decreases MAP, RSNA, and HR by the activation of ionotropic glutamate receptors. As a result, baroreflex control of RSNA and HR was dramatically attenuated. The astrocytic glutamate transporter in the NTS plays an important role in the maintenance and regulation of cardiovascular function.
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Affiliation(s)
- Kenta Yamamoto
- Department of Physiology and AnatomyUniversity of North Texas Health Science CentreFort WorthTexas
- Faculty of Pharmaceutical SciencesTeikyo Heisei UniversityTokyoJapan
| | - Steve Mifflin
- Department of Physiology and AnatomyUniversity of North Texas Health Science CentreFort WorthTexas
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Demars F, Clark K, Wyeth MS, Abrams E, Buckmaster PS. A single subconvulsant dose of domoic acid at mid-gestation does not cause temporal lobe epilepsy in mice. Neurotoxicology 2018; 66:128-137. [PMID: 29625197 PMCID: PMC5940543 DOI: 10.1016/j.neuro.2018.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/28/2018] [Accepted: 04/02/2018] [Indexed: 11/19/2022]
Abstract
Harmful blooms of domoic acid (DA)-producing algae are a problem in oceans worldwide. DA is a potent glutamate receptor agonist that can cause status epilepticus and in survivors, temporal lobe epilepsy. In mice, one-time low-dose in utero exposure to DA was reported to cause hippocampal damage and epileptiform activity, leading to the hypothesis that unrecognized exposure to DA from contaminated seafood in pregnant women can damage the fetal hippocampus and initiate temporal lobe epileptogenesis. However, development of epilepsy (i.e., spontaneous recurrent seizures) has not been tested. In the present study, long-term seizure monitoring and histology was used to test for temporal lobe epilepsy following prenatal exposure to DA. In Experiment One, the previous study's in utero DA treatment protocol was replicated, including use of the CD-1 mouse strain. Afterward, mice were video-monitored for convulsive seizures from 2 to 6 months old. None of the CD-1 mice treated in utero with vehicle or DA was observed to experience spontaneous convulsive seizures. After seizure monitoring, mice were evaluated for pathological evidence of temporal lobe epilepsy. None of the mice treated in utero with DA displayed the hilar neuron loss that occurs in patients with temporal lobe epilepsy and in the mouse pilocarpine model of temporal lobe epilepsy. In Experiment Two, a higher dose of DA was administered to pregnant FVB mice. FVB mice were tested as a potentially more sensitive strain, because they have a lower seizure threshold, and some females spontaneously develop epilepsy. Female offspring were monitored with continuous video and telemetric bilateral hippocampal local field potential recording at 1-11 months old. A similar proportion of vehicle- and DA-treated female FVB mice spontaneously developed epilepsy, beginning in the fourth month of life. Average seizure frequency and duration were similar in both groups. Seizure frequency was lower than that of positive-control pilocarpine-treated mice, but seizure duration was similar. None of the mice treated in utero with vehicle or DA displayed hilar neuron loss or intense mossy fiber sprouting, a form of aberrant synaptic reorganization that develops in patients with temporal lobe epilepsy and in pilocarpine-treated mice. FVB mice that developed epilepsy (vehicle- and DA-treated) displayed mild mossy fiber sprouting. Results of this study suggest that a single subconvulsive dose of DA at mid-gestation does not cause temporal lobe epilepsy in mice.
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Affiliation(s)
- Fanny Demars
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; VetAgro Sup, School of Veterinary Medicine, Lyon, France; Paris Descartes University, Paris, France
| | - Kristen Clark
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; College of Veterinary Medicine, Oklahoma State University, Stillwater, OK, United States
| | - Megan S Wyeth
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States
| | - Emily Abrams
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States
| | - Paul S Buckmaster
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA, United States.
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11
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Wang L, Liu Y, Lu R, Dong G, Chen X, Yun W, Zhou X. The role of S-nitrosylation of kainate-type of ionotropic glutamate receptor 2 in epilepsy induced by kainic acid. J Neurochem 2018; 144:255-270. [PMID: 29193067 DOI: 10.1111/jnc.14266] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 11/29/2022]
Abstract
Epilepsy is a chronic brain disease affecting millions of individuals. Kainate receptors, especially kainate-type of ionotropic glutamate receptor 2 (GluK2), play an important role in epileptogenesis. Recent data showed that GluK2 could undergo post-translational modifications in terms of S-nitrosylation (SNO), and affect the signaling pathway of cell death in cerebral ischemia-reperfusion. However, it is unclear whether S-nitrosylation of GluK2 (SNO-GluK2) contributes to cell death induced by epilepsy. Here, we report that kainic acid-induced SNO-GluK2 is mediated by GluK2 itself, regulated by neuronal nitric oxide synthase (nNOS) and the level of cytoplasmic calcium in vivo and in vitro hippocampus neurons. The whole-cell patch clamp recordings showed the influence of SNO-GluK2 on ion channel characterization of GluK2-Kainate receptors. Moreover, immunohistochemistry staining results showed that inhibition of SNO-GluK2 by blocking nNOS or GluK2 or by reducing the level of cytoplasmic calcium-protected hippocampal neurons from kainic acid-induced injury. Finally, immunoprecipitation and western blotting data revealed the involvement of assembly of a GluK2-PSD95-nNOS signaling complex in epilepsy. Taken together, our results showed that the SNO-GluK2 plays an important role in neuronal injury of epileptic rats by forming GluK2-PSD95-nNOS signaling module in a cytoplasmic calcium-dependent way, suggesting a potential therapeutic target site for epilepsy.
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Affiliation(s)
- Linxiao Wang
- Laboratory of Neurological Diseases, The affiliated Changzhou No.2 People's Hospital with Nanjing Medical University, Changzhou, Jiangsu Province, China
| | - Yanyan Liu
- Department of Neurology, The affiliated Changzhou No.2 People's Hospital with Nanjing Medical University, Changzhou, Jiangsu Province, China
| | - Rulan Lu
- Laboratory of Neurological Diseases, The affiliated Changzhou No.2 People's Hospital with Nanjing Medical University, Changzhou, Jiangsu Province, China
| | - Guoying Dong
- Laboratory of Neurological Diseases, The affiliated Changzhou No.2 People's Hospital with Nanjing Medical University, Changzhou, Jiangsu Province, China
| | - Xia Chen
- Laboratory of Neurological Diseases, The affiliated Changzhou No.2 People's Hospital with Nanjing Medical University, Changzhou, Jiangsu Province, China
| | - Wenwei Yun
- Department of Neurology, The affiliated Changzhou No.2 People's Hospital with Nanjing Medical University, Changzhou, Jiangsu Province, China
| | - Xianju Zhou
- Laboratory of Neurological Diseases, The affiliated Changzhou No.2 People's Hospital with Nanjing Medical University, Changzhou, Jiangsu Province, China
- Department of Neurology, The affiliated Changzhou No.2 People's Hospital with Nanjing Medical University, Changzhou, Jiangsu Province, China
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12
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Yang H, Zhao N, Lv L, Yan X, Hu S, Xu T. Functional research and molecular mechanism of Kainic acid-induced denitrosylation of thioredoxin-1 in rat hippocampus. Neurochem Int 2017; 108:448-456. [PMID: 28603024 DOI: 10.1016/j.neuint.2017.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 05/31/2017] [Accepted: 06/07/2017] [Indexed: 10/19/2022]
Abstract
Thioredoxin-1 (Trx1) has long been recognized as a redox regulator, and is implicated in the inhibition of cell apoptosis. Trx1 is essential for the maintenance of the S-nitrosylation of molecules in cells. The S-nitrosylation of Trx1 is essential for the physiological function such as preservation of the redox regulatory activity. The mechanisms underlying Trx1 denitrosylation induced by kainate acid (KA) injection still remain uncharacterized. Our results showed that the S-nitrosylation levels of Trx1 were decreased subsequent to KA injection and that the glutamate receptor 6 (GluR6) antagonist NS102 could inhibit the denitrosylation of Trx1. Moreover, the denitrosylation of Trx1 following KA treatment could be suppressed by the Fas ligand (FasL) antisense oligodeoxynucleotides (AS-ODNs), the Trx reductase (TrxR) inhibitor dinitrochlorobenzene (DNCB), or the Nitric oxide (NO) donors sodium nitroprusside (SNP) and S-nitrosoglutathione (GSNO). Subsequently, these mechanisms were morphologically validated by cresyl violet staining, in situ TUNEL staining to detect the survival of CA1 and CA3/DG pyramidal neurons. NS102, FasL AS-ODNs, GSNO and SNP could provide neuroprotection of the pyramidal neurons of CA1 and CA3/dentate gyrus (DG) regions by attenuating Trx1 denitrosylation. Our results also showed that the denitrosylation of Trx1 induced by KA injection can active the caspase-3 which results in apoptosis.
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Affiliation(s)
- Hongning Yang
- Institute of Emergency Rescue Medicine, Xuzhou Medical University, Xuzhou 221002, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou 221004, China
| | - Ningjun Zhao
- Institute of Emergency Rescue Medicine, Xuzhou Medical University, Xuzhou 221002, China; Emergency Center of the Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China
| | - Lanxin Lv
- Institute of Emergency Rescue Medicine, Xuzhou Medical University, Xuzhou 221002, China
| | - Xianliang Yan
- Institute of Emergency Rescue Medicine, Xuzhou Medical University, Xuzhou 221002, China; Emergency Center of the Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
| | - Shuqun Hu
- Institute of Emergency Rescue Medicine, Xuzhou Medical University, Xuzhou 221002, China.
| | - Tie Xu
- Institute of Emergency Rescue Medicine, Xuzhou Medical University, Xuzhou 221002, China; Emergency Center of the Affiliated Hospital of Xuzhou Medical University, Xuzhou 221002, China.
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13
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Vu HT, Akatsu H, Hashizume Y, Setou M, Ikegami K. Increase in α-tubulin modifications in the neuronal processes of hippocampal neurons in both kainic acid-induced epileptic seizure and Alzheimer's disease. Sci Rep 2017; 7:40205. [PMID: 28067280 PMCID: PMC5220350 DOI: 10.1038/srep40205] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 12/05/2016] [Indexed: 12/31/2022] Open
Abstract
Neurodegeneration includes acute changes and slow-developing alterations, both of which partly involve common cellular machinery. During neurodegeneration, neuronal processes are impaired along with dysregulated post-translational modifications (PTMs) of cytoskeletal proteins. In neuronal processes, tubulin undergoes unique PTMs including a branched form of modification called glutamylation and loss of the C-terminal tyrosine residue and the penultimate glutamic acid residue forming Δ2-tubulin. Here, we investigated the state of two PTMs, glutamylation and Δ2 form, in both acute and slow-developing neurodegenerations, using a newly generated monoclonal antibody, DTE41, which had 2-fold higher affinity to glutamylated Δ2-tubulin, than to unmodified Δ2-tubulin. DTE41 recognised glutamylated Δ2-tubulin preferentially in immunostaining than in enzyme-linked immunosorbent assay and immunoblotting. In normal mouse brain, DTE41 stained molecular layer of the cerebellum as well as synapse-rich regions in pyramidal neurons of the cerebral cortex. In kainic acid-induced epileptic seizure, DTE41-labelled signals were increased in the hippocampal CA3 region, especially in the stratum lucidum. In the hippocampi of post-mortem patients with Alzheimer's disease, intensities of DTE41 staining were increased in mossy fibres in the CA3 region as well as in apical dendrites of the pyramidal neurons. Our findings indicate that glutamylation on Δ2-tubulin is increased in both acute and slow-developing neurodegeneration.
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Affiliation(s)
- Hang Thi Vu
- Department of Cellular and Molecular Anatomy, and International Mass Imaging Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Hiroyasu Akatsu
- Choju Medical Institute, Fukushimura Hospital, Toyohashi, Japan
- Department of Medicine for Aging in Place and Community-Based Medical Education, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | | | - Mitsutoshi Setou
- Department of Cellular and Molecular Anatomy, and International Mass Imaging Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
- Department of Systems Molecular Anatomy, Preeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
- Department of Anatomy, The University of Hong Kong, Hong Kong, China
- Division of Neural Systematics, National Institute for Physiological Sciences, Okazaki, Japan
- Riken Center for Molecular Imaging Science, Kobe, Japan
| | - Koji Ikegami
- Department of Cellular and Molecular Anatomy, and International Mass Imaging Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
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Almeida Silva LF, Engel T, Reschke CR, Conroy RM, Langa E, Henshall DC. Distinct behavioral and epileptic phenotype differences in 129/P mice compared to C57BL/6 mice subject to intraamygdala kainic acid-induced status epilepticus. Epilepsy Behav 2016; 64:186-194. [PMID: 27744244 DOI: 10.1016/j.yebeh.2016.09.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/12/2016] [Accepted: 09/16/2016] [Indexed: 12/31/2022]
Abstract
Animal models of status epilepticus are important tools to understand the pathogenesis of epileptic brain injury and evaluate potential seizure-suppressive, neuroprotective, and antiepileptogenic treatments. Focal elicitation of status epilepticus by intraamygdala kainic acid in mice produces unilateral hippocampal damage and the emergence of spontaneous recurrent seizures after a short latent period. The model has been characterized in C57BL/6, BALB/c, and SJL mice where strain-specific differences were found in the extent of hippocampal damage. 129/P mice are a common background strain for genetic models and may display unique characteristics in this model. We therefore compared responses to intraamygdala kainic acid between 129/P and C57BL/6 mice. Racine scale-scored convulsive behavior during status epilepticus was substantially lower in 129/P mice compared with that in C57BL/6 mice. Analysis of surface-recorded electroencephalogram (EEG) showed differences between strains in several frequency bands; EEG total power was greater during ictal episodes while duration of seizures was slightly shorter in 129/P mice. Histological analysis revealed similar hippocampal injury between strains, with neuronal death mainly confined to the ipsilateral CA3 subfield. Expression of genes associated with gliosis and neuroinflammatory responses was also similar between strains after seizures. Video-EEG telemetry recordings showed that 129/P mice first display spontaneous seizures within a few days of status epilepticus similar to C57BL/6 mice. However, high mortality in 129/P mice prevented a quantitative comparison of the epileptic seizure phenotypes between strains. This study defined behavioral, EEG, and histopathologic features of this mouse strain in a model increasingly useful for the study of the genetic contribution to acquired epilepsy. Intraamygdala kainic acid in 129/P mice could serve as a model of nonconvulsive status epilepticus, but long-term assessments will require model adjustment to mitigate the severity of the emergent epileptic phenotype.
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Affiliation(s)
- Luiz Fernando Almeida Silva
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin, 2, Ireland
| | - Tobias Engel
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin, 2, Ireland
| | - Cristina R Reschke
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin, 2, Ireland
| | - Ronan M Conroy
- Division of Population Health Sciences, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin, 2, Ireland
| | - Elena Langa
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin, 2, Ireland
| | - David C Henshall
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin, 2, Ireland.
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15
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Heischmann S, Quinn K, Cruickshank-Quinn C, Liang LP, Reisdorph R, Reisdorph N, Patel M. Exploratory Metabolomics Profiling in the Kainic Acid Rat Model Reveals Depletion of 25-Hydroxyvitamin D3 during Epileptogenesis. Sci Rep 2016; 6:31424. [PMID: 27526857 PMCID: PMC4985632 DOI: 10.1038/srep31424] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 07/20/2016] [Indexed: 12/02/2022] Open
Abstract
Currently, no reliable markers are available to evaluate the epileptogenic potential of a brain injury. The electroencephalogram is the standard method of diagnosis of epilepsy; however, it is not used to predict the risk of developing epilepsy. Biomarkers that indicate an individual's risk to develop epilepsy, especially those measurable in the periphery are urgently needed. Temporal lobe epilepsy (TLE), the most common form of acquired epilepsy, is characterized by spontaneous recurrent seizures following brain injury and a seizure-free "latent" period. Elucidation of mechanisms at play during epilepsy development (epileptogenesis) in animal models of TLE could enable the identification of predictive biomarkers. Our pilot study using liquid chromatography-mass spectrometry metabolomics analysis revealed changes (p-value ≤ 0.05, ≥1.5-fold change) in lipid, purine, and sterol metabolism in rat plasma and hippocampus during epileptogenesis and chronic epilepsy in the kainic acid model of TLE. Notably, disease development was associated with dysregulation of vitamin D3 metabolism at all stages and plasma 25-hydroxyvitamin D3 depletion in the acute and latent phase of injury-induced epileptogenesis. These data suggest that plasma VD3 metabolites reflect the severity of an epileptogenic insult and that a panel of plasma VD3 metabolites may be able to serve as a marker of epileptogenesis.
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Affiliation(s)
- Svenja Heischmann
- Department of Pharmaceutical Sciences, University of Colorado, School of Pharmacy, 12850 East Montview Boulevard, Aurora, CO 80045, USA
- Department of Immunology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206, USA
| | - Kevin Quinn
- Department of Immunology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206, USA
| | | | - Li-Ping Liang
- Department of Pharmaceutical Sciences, University of Colorado, School of Pharmacy, 12850 East Montview Boulevard, Aurora, CO 80045, USA
| | - Rick Reisdorph
- Department of Immunology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206, USA
| | - Nichole Reisdorph
- Department of Immunology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206, USA
| | - Manisha Patel
- Department of Pharmaceutical Sciences, University of Colorado, School of Pharmacy, 12850 East Montview Boulevard, Aurora, CO 80045, USA
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Twele F, Töllner K, Brandt C, Löscher W. Significant effects of sex, strain, and anesthesia in the intrahippocampal kainate mouse model of mesial temporal lobe epilepsy. Epilepsy Behav 2016; 55:47-56. [PMID: 26736063 DOI: 10.1016/j.yebeh.2015.11.027] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 11/24/2015] [Accepted: 11/24/2015] [Indexed: 01/12/2023]
Abstract
The intrahippocampal kainate mouse model of mesial temporal lobe epilepsy is increasingly being used for studies on epileptogenesis and antiepileptogenesis. Almost all previous studies used male mice for this purpose, and no study is available in this or other models of acquired epilepsy that directly compared epileptogenesis in female and male rodents. Epidemiological studies suggest that gender may affect susceptibility to epilepsy and its prognosis; therefore, one goal of this study was to investigate whether sex has an influence on latent period and epileptogenesis in the intrahippocampal kainate model in mice. Another aspect that was examined in the present study was whether mouse strain differences in epileptogenesis exist. Finally, we examined the effects of different types of anesthesia (chloral hydrate, isoflurane) on kainate-induced status epilepticus (SE) and epileptogenesis. Continuous (24/7) video-EEG monitoring was used during SE and the 2 weeks following SE as well as 4-6 weeks after SE. In male NMRI mice with chloral hydrate anesthesia during kainate injection, SE was followed by a seizure-free latent period of 10-14 days if hippocampal paroxysmal discharges (HPDs) recorded from the kainate focus were considered the onset of epilepsy. Anesthesia with isoflurane led to a more rapid onset and higher severity of SE, and not all male NMRI mice exhibited a seizure-free latent period. Female NMRI mice differed from male animals in the lack of any clear latent period, independently of anesthesia type. Furthermore, HPDs were only rarely observed. These problems were not resolved by decreasing the dose of kainate or using other strains (C57BL/6, FVB/N) of female mice. The present data are the first to demonstrate marked sex-related differences in the latent period following brain injury in a rodent model of acquired epilepsy. Furthermore, our data demonstrate that the choice of anesthestic agent during kainate administration affects SE severity and as a consequence, the latent period, which may explain some of the differences reported for this model in the literature.
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Affiliation(s)
- Friederike Twele
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Kathrin Töllner
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Claudia Brandt
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
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Pallo SP, DiMaio J, Cook A, Nilsson B, Johnson GVW. Mechanisms of tau and Aβ-induced excitotoxicity. Brain Res 2015; 1634:119-131. [PMID: 26731336 DOI: 10.1016/j.brainres.2015.12.048] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 12/09/2015] [Accepted: 12/17/2015] [Indexed: 11/18/2022]
Abstract
Excitotoxicity was originally postulated to be a late stage side effect of Alzheimer׳s disease (AD)-related neurodegeneration, however more recent studies indicate that it may occur early in AD and contribute to the neurodegenerative process. Tau and amyloid beta (Aβ), the main components of neurofibrillary tangles (NFTs) and amyloid plaques, have been implicated in cooperatively and independently facilitating excitotoxicity. Our study investigated the roles of tau and Aβ in AD-related excitotoxicity. In vivo studies showed that tau knockout (tau(-/-)) mice were significantly protected from seizures and hippocampal superoxide production induced with the glutamate analog, kainic acid (KA). We hypothesized that tau accomplished this by facilitating KA-induced Ca(2+) influx into neurons, however lentiviral tau knockdown failed to ameliorate KA-induced Ca(2+) influx into primary rat cortical neurons. We further investigated if tau cooperated with Aβ to facilitate KA-induced Ca(2+) influx. While Aβ biphasically modulated the KA-induced Cacyt(2+) responses, tau knockdown continued to have no effect. Therefore, tau facilitates KA-induced seizures and superoxide production in a manner that does not involve facilitation of Ca(2+) influx through KA receptors (KAR). On the other hand, acute pretreatment with Aβ (10 min) enhanced KA-induced Ca(2+) influx, while chronic Aβ (24 h) significantly reduced it, regardless of tau knockdown. Given previously published connections between Aβ, group 1 metabotropic glutamate receptors (mGluRs), and KAR regulation, we hypothesized that Aβ modulates KAR via a G-protein coupled receptor pathway mediated by group 1 mGluRs. We found that Aβ did not activate group 1 mGluRs and inhibition of these receptors did not reverse Aβ modulation of KA-induced Ca(2+) influx. Therefore, Aβ biphasically regulates KAR via a mechanism that does not involve group 1mGluR activation.
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Affiliation(s)
- Susanne P Pallo
- Department of Anesthesiology, University of Rochester Medical Center, Rochester, NY, USA.
| | - John DiMaio
- Department of Chemistry, University of Rochester, Rochester, NY, USA.
| | - Alexis Cook
- Department of Anesthesiology, University of Rochester Medical Center, Rochester, NY, USA.
| | - Bradley Nilsson
- Department of Chemistry, University of Rochester, Rochester, NY, USA.
| | - Gail V W Johnson
- Department of Anesthesiology, University of Rochester Medical Center, Rochester, NY, USA.
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Juárez-Rebollar D, Manjarrez J, Nava-Ruíz C, Zaga-Clavellina V, Flores-Espinosa P, Heras-Romero Y, Díaz-Ruíz A, Méndez-Armenta M. Metallothionein expression in the rat brain following KA and PTZ treatment. Environ Toxicol Pharmacol 2015; 40:530-534. [PMID: 26318565 DOI: 10.1016/j.etap.2015.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 07/28/2015] [Accepted: 08/06/2015] [Indexed: 06/04/2023]
Abstract
Epilepsy is a neurological disorder that has been associated with oxidative stress therefore epilepsy models have been develop such as kainic acid and pentylenetetrazol are usually used to understanding of the molecular mechanisms of this disease. We examined the metallothionein expression in rat brains of treated with kainic acid and pentylenetetrazol. Increase in metallothionein and nitrotirosyne immunoreactivity of both seizures epilepsy models was observed. Moreover, we show a significant increase on levels of MT expression. These results suggest that the increase of metallothionein expression is related with kainic acid and pentylenetetrazol treatments as response to damage mediated by oxidative stress.
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Affiliation(s)
- Daniel Juárez-Rebollar
- Lab. Neuropatología Experimental, Instituto Nacional de Neurología y Neurocirugía, Manuel Velasco Suárez, Mexico
| | - Joaquín Manjarrez
- Lab. Formación Reticular, Instituto Nacional de Neurología y Neurocirugía, Manuel Velasco Suárez, Mexico
| | - Concepción Nava-Ruíz
- Lab. Neuropatología Experimental, Instituto Nacional de Neurología y Neurocirugía, Manuel Velasco Suárez, Mexico
| | - Verónica Zaga-Clavellina
- Lab. Biología Celular, Instituto Nacional de Perinatología, Isidro Espinosa de los Reyes, Mexico
| | - Pilar Flores-Espinosa
- Lab. Biología Celular, Instituto Nacional de Perinatología, Isidro Espinosa de los Reyes, Mexico
| | - Yesica Heras-Romero
- Depto. Etología, Fauna Silvesre y Animales de Laboratorio, Facultad de Medicina Veterinaria y Zootecnia, U.N.A.M, Mexico
| | - Araceli Díaz-Ruíz
- Depto. Neuroquímica, Instituto Nacional de Neurología y Neurocirugía, Manuel Velasco Suárez, Mexico
| | - Marisela Méndez-Armenta
- Lab. Neuropatología Experimental, Instituto Nacional de Neurología y Neurocirugía, Manuel Velasco Suárez, Mexico.
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19
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Guggenhuber S, Alpar A, Chen R, Schmitz N, Wickert M, Mattheus T, Harasta AE, Purrio M, Kaiser N, Elphick MR, Monory K, Kilb W, Luhmann HJ, Harkany T, Lutz B, Klugmann M. Cannabinoid receptor-interacting protein Crip1a modulates CB1 receptor signaling in mouse hippocampus. Brain Struct Funct 2015; 221:2061-74. [PMID: 25772509 DOI: 10.1007/s00429-015-1027-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 03/06/2015] [Indexed: 12/13/2022]
Abstract
The cannabinoid type 1 receptor (Cnr1, CB1R) mediates a plethora of physiological functions in the central nervous system as a presynaptic modulator of neurotransmitter release. The recently identified cannabinoid receptor-interacting protein 1a (Cnrip1a, CRIP1a) binds to the C-terminal domain of CB1R, a region known to be important for receptor desensitization and internalization. Evidence that CRIP1a and CB1R interact in vivo has been reported, but the neuroanatomical distribution of CRIP1a is unknown. Moreover, while alterations of hippocampal CRIP1a levels following limbic seizures indicate a role in controlling excessive neuronal activity, the physiological function of CRIP1a in vivo has not been investigated. In this study, we analyzed the spatial distribution of CRIP1a in the hippocampus and examined CRIP1a as a potential modulator of CB1R signaling. We found that Cnrip1a mRNA is co-expressed with Cnr1 mRNA in pyramidal neurons and interneurons of the hippocampal formation. CRIP1a protein profiles were largely segregated from CB1R profiles in mossy cell terminals but not in hippocampal CA1 region. CB1R activation induced relocalization to close proximity with CRIP1a. Adeno-associated virus-mediated overexpression of CRIP1a specifically in the hippocampus revealed that CRIP1a modulates CB1R activity by enhancing cannabinoid-induced G protein activation. CRIP1a overexpression extended the depression of excitatory currents by cannabinoids in pyramidal neurons of the hippocampus and diminished the severity of chemically induced acute epileptiform seizures. Collectively, our data indicate that CRIP1a enhances hippocampal CB1R signaling in vivo.
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Affiliation(s)
- Stephan Guggenhuber
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany
| | - Alan Alpar
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles väg 1:A1, 17177, Stockholm, Sweden
- Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences, Budapest, Hungary
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Rongqing Chen
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany
| | - Nina Schmitz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany
| | - Melanie Wickert
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany
| | - Tobias Mattheus
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany
| | - Anne E Harasta
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany
- Department of Physiology and Translational Neuroscience Facility, School of Medical Sciences, UNSW, High Street, Randwick, Sydney, NSW, 2052, Australia
| | - Martin Purrio
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany
| | - Nadine Kaiser
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany
| | - Maurice R Elphick
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Krisztina Monory
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany
| | - Tibor Harkany
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles väg 1:A1, 17177, Stockholm, Sweden
- Department of Molecular Neuroscience, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090, Vienna, Austria
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany.
| | - Matthias Klugmann
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University, 55128, Mainz, Germany.
- Department of Physiology and Translational Neuroscience Facility, School of Medical Sciences, UNSW, High Street, Randwick, Sydney, NSW, 2052, Australia.
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20
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Hiolski EM, Kendrick PS, Frame ER, Myers MS, Bammler TK, Beyer RP, Farin FM, Wilkerson HW, Smith DR, Marcinek DJ, Lefebvre KA. Chronic low-level domoic acid exposure alters gene transcription and impairs mitochondrial function in the CNS. Aquat Toxicol 2014; 155:151-9. [PMID: 25033243 PMCID: PMC4139102 DOI: 10.1016/j.aquatox.2014.06.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/09/2014] [Accepted: 06/13/2014] [Indexed: 05/10/2023]
Abstract
Domoic acid is an algal-derived seafood toxin that functions as a glutamate agonist and exerts excitotoxicity via overstimulation of glutamate receptors (AMPA, NMDA) in the central nervous system (CNS). At high (symptomatic) doses, domoic acid is well-known to cause seizures, brain lesions and memory loss; however, a significant knowledge gap exists regarding the health impacts of repeated low-level (asymptomatic) exposure. Here, we investigated the impacts of low-level repetitive domoic acid exposure on gene transcription and mitochondrial function in the vertebrate CNS using a zebrafish model in order to: (1) identify transcriptional biomarkers of exposure; and (2) examine potential pathophysiology that may occur in the absence of overt excitotoxic symptoms. We found that transcription of genes related to neurological function and development were significantly altered, and that asymptomatic exposure impaired mitochondrial function. Interestingly, the transcriptome response was highly variable across the exposure duration (36 weeks), with little to no overlap of specific genes across the six exposure time points (2, 6, 12, 18, 24, and 36 weeks). Moreover, there were no apparent similarities at any time point with the gene transcriptome profile exhibited by the glud1 mouse model of chronic moderate excess glutamate release. These results suggest that although the fundamental mechanisms of toxicity may be similar, gene transcriptome responses to domoic acid exposure do not extrapolate well between different exposure durations. However, the observed impairment of mitochondrial function based on respiration rates and mitochondrial protein content suggests that repetitive low-level exposure does have fundamental cellular level impacts that could contribute to chronic health consequences.
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Affiliation(s)
- Emma M Hiolski
- University of California, Santa Cruz, CA 95064, United States.
| | | | - Elizabeth R Frame
- NOAA Northwest Fisheries Science Center, Seattle, WA 98112, United States.
| | - Mark S Myers
- University of Washington, Seattle, WA 98112, United States.
| | - Theo K Bammler
- University of Washington, Seattle, WA 98112, United States.
| | | | | | | | - Donald R Smith
- University of California, Santa Cruz, CA 95064, United States.
| | | | - Kathi A Lefebvre
- NOAA Northwest Fisheries Science Center, Seattle, WA 98112, United States.
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21
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Cortés Castell E, Veciana Galindo C, Torro Montell L, Sirvent Segura E, Rizo Baeza MM, Gil Guillén V. [Effect on zebrafish neurodevelopment and neuroprotection of a polyphenolic extract olive seeds]. NUTR HOSP 2014; 30:338-342. [PMID: 25208788 DOI: 10.3305/nh.2014.30.2.7604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Abstract
OBJECTIVE To determine the effect of a polyphenolic extract from olive pit on the development of the nervous system as well as its effect on pain induced by the neurotoxin kainic acid, taking the zebrafish as the animal model. MATERIAL AND METHODS We analyse the effect of the extract at the maximum tolerated dose (100 mg/ml of polyphenols) on the cholinergic activity in zebrafish larvae (72 hours post-fertilization). Only fecundated eggs with no abnormalities are used. 6 eggs/bowl are incubated in a 24 bowls microplate in 2 ml of water with DMSO (0.1%) at 26 ± 1º C: a) neurodevelopment: water (control) and 100 mg/ml of extract, as an essay; b) neuroprotection: water and kainic acid (100 μM) (control) and 100 mg/ml of extract (essay). All incubations are in triplicate. After 72 h, incubations are examined and checked for any abnormalities. Larvae are homogenized and acetyl cholinesterase activity and protein concentration in supernatants is quantified. RESULTS The quantity of protein and the morphologic appreciation is similar in all the essays, showing a standard development. Acetyl cholinesterase in fish larvae, with the polyphenolic extract is 162.2% (SD 44.2) compared to controls (100% of activity) (p < 0.01). Fish larvae treated with kainic acid and polyphenolic acid show 140.1% (SD 22.0) of activity, compared to those only incubated with the neurotoxin (100%) (p < 0.05). CONCLUSION Polyphenols extracted from olive pit produce an increase in the cholinergic activity during the larvae neurodevelopment in the zebrafish as well as protection against the neurotoxin kainic acid.
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Affiliation(s)
- Ernesto Cortés Castell
- Departamento de Farmacología, Pediatría y Q. Orgánica. Universidad Miguel Hernández. Campus de San Juan. Alicante. España..
| | | | | | | | - M M Rizo Baeza
- Departamento de Enfermería y Nutrición. Universidad de Alicante..
| | - V Gil Guillén
- Departamento de Medicina Clínica. Universidad Miguel Hernández. España..
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22
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Jeong HK, Ji KM, Min KJ, Choi I, Choi DJ, Jou I, Joe EH. Astrogliosis is a possible player in preventing delayed neuronal death. Mol Cells 2014; 37:345-55. [PMID: 24802057 PMCID: PMC4012084 DOI: 10.14348/molcells.2014.0046] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 03/27/2014] [Accepted: 03/28/2014] [Indexed: 12/11/2022] Open
Abstract
Mitigating secondary delayed neuronal injury has been a therapeutic strategy for minimizing neurological symptoms after several types of brain injury. Interestingly, secondary neuronal loss appeared to be closely related to functional loss and/or death of astrocytes. In the brain damage induced by agonists of two glutamate receptors, N-ethyl-D-aspartic acid (NMDA) and kainic acid (KA), NMDA induced neuronal death within 3 h, but did not increase further thereafter. However, in the KA-injected brain, neuronal death was not obviously detectable even at injection sites at 3 h, but extensively increased to encompass the entire hemisphere at 7 days. Brain inflammation, a possible cause of secondary neuronal damage, showed little differences between the two models. Importantly, however, astrocyte behavior was completely different. In the NMDA-injected cortex, the loss of glial fibrillary acidic protein-expressing (GFAP+) astrocytes was confined to the injection site until 7 days after the injection, and astrocytes around the damage sites showed extensive gliosis and appeared to isolate the damage sites. In contrast, in the KA-injected brain, GFAP+ astrocytes, like neurons, slowly, but progressively, disappeared across the entire hemisphere. Other markers of astrocytes, including S100β, glutamate transporter EAAT2, the potassium channel Kir4.1 and glutamine synthase, showed patterns similar to that of GFAP in both NMDA- and KA-injected cortexes. More importantly, astrocyte disappearance and/or functional loss preceded neuronal death in the KA-injected brain. Taken together, these results suggest that loss of astrocyte support to neurons may be a critical cause of delayed neuronal death in the injured brain.
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Affiliation(s)
- Hey-Kyeong Jeong
- Department of Pharmacology, Ajou University School of Medicine, Suwon 442-721,
Korea
- Department of Biomedical Sciences Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 442-721,
Korea
- Brain Disease Research Center, Ajou University School of Medicine, Suwon 442-721,
Korea
| | - Kyung-Min Ji
- Department of Pharmacology, Ajou University School of Medicine, Suwon 442-721,
Korea
- Department of Biomedical Sciences Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 442-721,
Korea
- Brain Disease Research Center, Ajou University School of Medicine, Suwon 442-721,
Korea
| | - Kyoung-Jin Min
- Department of Pharmacology, Ajou University School of Medicine, Suwon 442-721,
Korea
- Department of Biomedical Sciences Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 442-721,
Korea
- Brain Disease Research Center, Ajou University School of Medicine, Suwon 442-721,
Korea
| | - Insup Choi
- Department of Pharmacology, Ajou University School of Medicine, Suwon 442-721,
Korea
- Department of Biomedical Sciences Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 442-721,
Korea
- Department of Brain Science, Ajou University School of Medicine, Suwon 442-721,
Korea
| | - Dong-Joo Choi
- Department of Pharmacology, Ajou University School of Medicine, Suwon 442-721,
Korea
- Department of Biomedical Sciences Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 442-721,
Korea
- Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 442-721,
Korea
- Department of Brain Science, Ajou University School of Medicine, Suwon 442-721,
Korea
| | - Ilo Jou
- Department of Pharmacology, Ajou University School of Medicine, Suwon 442-721,
Korea
- Department of Biomedical Sciences Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 442-721,
Korea
- Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 442-721,
Korea
| | - Eun-Hye Joe
- Department of Pharmacology, Ajou University School of Medicine, Suwon 442-721,
Korea
- Department of Biomedical Sciences Neuroscience Graduate Program, Ajou University School of Medicine, Suwon 442-721,
Korea
- Brain Disease Research Center, Ajou University School of Medicine, Suwon 442-721,
Korea
- Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 442-721,
Korea
- Department of Brain Science, Ajou University School of Medicine, Suwon 442-721,
Korea
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23
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Gordon RY, Shubina LV, Kapralova MV, Pershina EB, Khutzian SS, Arhipov VI. [Peculiarities of neurodegeneration in hippocampus fields after kainic acid action in rats]. Tsitologiia 2014; 56:919-25. [PMID: 25929133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Comparison between results of different ways of application of excitotoxin (kainic acid, KA), intrahippocampal (0.2 μg/μl) and intraventricular (0.6 μg/μl), was carried out in the course of investigations of the prolonged action of KA on the morphological state of various fields in dorsal hippocampus. Light microscopy with Cresyl Violet staining and fluorescent microscopy with staining by fluoro-jade B were used in our researches. The results revealed that KA, being injected intrahippocampally at a dose, which does not result in animal epileptization, caused obvious degenerative phenomena in hippocampus. Two weeks after KA injection the layers of pyramid cells in the fields CA3 and CA4 were absent, and in four weeks, degenerative changes and cell lysis were spread on the CA1 field as well. Four weeks after KA intraventricular administration in rats with epileptic status the damages of various levels were observed in hippocampus, from partial injuries of pyramid neurons in the fields CA3 and CA4 up to full loss of layers of pyramids in the fields CA1, CA3 and CA4. In both ways of KA injection, in the CA2 field the layer of cells mainly remained undamaged what indicates a special role of this field. After a single-time KA administration the both ways of injection led to the long-term damages of a neural tissue, possibly, of a general character, but differing in rates of neuron reactions in different fields to the damaging factor. An explanation of the prolonged action of KA excitotoxicity might be in the activation of GluR6-containing kainate receptors in pyramid neurons in CA3 field which brings to chronic character in single-time KA action and promotes the destruction of the remaining neurons by necrotic way while at the initial stage of KA influence the neurons perish by apoptotic way.
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24
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Chen N, Liu C, Yan N, Hu W, Zhang JG, Ge Y, Meng FG. A macaque model of mesial temporal lobe epilepsy induced by unilateral intrahippocampal injection of kainic Acid. PLoS One 2013; 8:e72336. [PMID: 23991095 PMCID: PMC3753347 DOI: 10.1371/journal.pone.0072336] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 07/08/2013] [Indexed: 11/18/2022] Open
Abstract
Objective In order to better investigate the cause/effect relationships of human mesial temporal lobe epilepsy (mTLE), we hereby describe a new non-human primate model of mTLE. Methods Ten macaques were studied and divided into 2 groups: saline control group (n = 4) and kainic acid (KA) injection group (n = 6). All macaques were implanted bilaterally with subdural electrodes over temporal cortex and depth electrodes in CA3 hippocampal region. KA was stereotaxically injected into the right hippocampus of macaques. All animals were monitored by video and electrocorticography (ECoG) to assess status epilepticus (SE) and subsequent spontaneous recurrent seizures (SRS). Additionally, in order to evaluate brain injury produced by SE or SRS, we used both neuroimaging, including magnetic resonance image (MRI) & magnetic resonance spectroscopy (MRS), and histological pathology, including Nissl stainning and glial fibrillary acid protein (GFAP) immunostaining. Results The typical seizures were observed in the KA-injected animal model. Hippocampal sclerosis could be found by MRI & MRS. Hematoxylin and eosin (H&E) staining and GFAP immunostaining showed neuronal loss, proliferation of glial cells, formation of glial scars, and hippocampal atrophy. Electron microscopic analysis of hippocampal tissues revealed neuronal pyknosis, partial ribosome depolymerization, an abnormal reduction in rough endoplasmic reticulum size, expansion of Golgi vesicles and swollen star-shaped cells. Furthermore, we reported that KA was able to induce SE followed by SRS after a variable period of time. Similar to human mTLE, brain damage is confined to the hippocampus. Accordingly, hippocampal volume is in positive correlations with the neuronal cells count in the CA3, especially the ratio of neuron/glial cell. Conclusions The results suggest that a model of mTLE can be developed in macaques by intra-hippocampal injection of KA. Brain damage is confined to the hippocampus which is similar to the human mTLE. The hippocampal volume correlates with the extension of the hippocampal damage.
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Affiliation(s)
- Ning Chen
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Chong Liu
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Na Yan
- School of Public Health and Family Medicine, Capital Medical University, Beijing, China
| | - Wei Hu
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Jian-guo Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yan Ge
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Fan-gang Meng
- Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
- * E-mail:
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25
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Mitra NK, Goh TEW, Bala Krishnan T, Nadarajah VD, Vasavaraj AK, Soga T. Effect of intra-cisternal application of kainic acid on the spinal cord and locomotor activity in rats. Int J Clin Exp Pathol 2013; 6:1505-1515. [PMID: 23923068 PMCID: PMC3726965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Accepted: 06/27/2013] [Indexed: 06/02/2023]
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease of idiopathic etiology. Glutamate excitotoxicity is one of the proposed hypotheses causing progressive death of motor neurons. We aimed to develop an experimental animal model of this disease to enhance the knowledge of pathophysiological mechanism of ALS. Male Wistar rats were infused with Kainic acid (KA) intra-cisternally for 5 days at the dosage of 50 fmol/day and 150 fmol/day. Locomotor activity, sensory function and histological changes in cervical and lumbar sections of spinal cord were evaluated. Glial Fibrillary Acidic Protein (GFAP) and Neurofilament Protein (NFP) were used as immunohistochemical marker for reactive astrogliosis and neuronal damage respectively. Specific Superoxide Dismutase (SOD) activity of spinal cord was estimated. The locomotor activity in the parameter of observed mean action time remained reduced on 14(th) day after administration of KA. Spinal motor neurons under Nissl stain showed pyknosis of nucleus and vacuolation of neuropil. GFAP expression increased significantly in the lumbar section of the spinal cord with high dose of KA treatment (p<0.05). NFP was expressed in axonal fibres around the neurons in KA-treated rats. A significant increase in specific SOD activity in both cervical and lumbar sections of the spinal cord was found with low dose of KA treatment (p<0.05). This study concludes that spinal cord damage with some features similar to ALS can be produced by low dose intra-cisternal administration of KA.
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Affiliation(s)
- Nilesh K Mitra
- School of Medicine, Taylor's University, Subang Jaya, Selangor, Malaysia.
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26
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Lowry ER, Kruyer A, Norris EH, Cederroth CR, Strickland S. The GluK4 kainate receptor subunit regulates memory, mood, and excitotoxic neurodegeneration. Neuroscience 2013; 235:215-25. [PMID: 23357115 DOI: 10.1016/j.neuroscience.2013.01.029] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 01/09/2013] [Accepted: 01/10/2013] [Indexed: 01/28/2023]
Abstract
Though the GluK4 kainate receptor subunit shows limited homology and a restricted expression pattern relative to other kainate receptor subunits, its ablation results in distinct behavioral and molecular phenotypes. GluK4 knockout mice demonstrated impairments in memory acquisition and recall in a Morris water maze test, suggesting a previously unreported role for kainate receptors in spatial memory. GluK4 knockout mice also showed marked hyperactivity and impaired pre-pulse inhibition, thereby mirroring two of the hallmark endophenotypes of patients with schizophrenia and bipolar disorder. Furthermore, we found that GluK4 is a key mediator of excitotoxic neurodegeneration: GluK4 knockout mice showed robust neuroprotection in the CA3 region of the hippocampus following intrahippocampal injection of kainate and widespread neuroprotection throughout the hippocampus following hypoxia-ischemia. Biochemical analysis of kainate- or sham-treated wild-type and GluK4 knockout hippocampal tissue suggests that GluK4 may act through the JNK pathway to regulate the molecular cascades that lead to excitotoxicity. Together, our findings suggest that GluK4 may be relevant to the understanding and treatment of human neuropsychiatric and neurodegenerative disorders.
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MESH Headings
- Affect/physiology
- Animals
- Blotting, Western
- Brain Ischemia/physiopathology
- Brain Ischemia/psychology
- CA3 Region, Hippocampal/physiology
- Cell Death/drug effects
- Evoked Potentials, Auditory, Brain Stem/drug effects
- Excitatory Amino Acid Agonists/administration & dosage
- Excitatory Amino Acid Agonists/toxicity
- Hippocampus
- Hypoxia, Brain/physiopathology
- Hypoxia, Brain/psychology
- JNK Mitogen-Activated Protein Kinases/genetics
- Kainic Acid/administration & dosage
- Kainic Acid/toxicity
- Maze Learning/drug effects
- Maze Learning/physiology
- Memory/physiology
- Mice
- Mice, Knockout
- Microinjections
- Motor Activity/drug effects
- Neurodegenerative Diseases/chemically induced
- Neurodegenerative Diseases/genetics
- Neurons/drug effects
- Receptors, Kainic Acid/genetics
- Receptors, Kainic Acid/physiology
- Reflex, Startle/drug effects
- Stereotaxic Techniques
- Stroke/genetics
- Stroke/pathology
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Affiliation(s)
- E R Lowry
- Laboratory of Neurobiology & Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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27
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Baron AW, Rushton SP, Rens N, Morris CM, Blain PG, Judge SJ. Sex differences in effects of low level domoic acid exposure. Neurotoxicology 2013; 34:1-8. [PMID: 23099319 DOI: 10.1016/j.neuro.2012.10.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 10/04/2012] [Accepted: 10/15/2012] [Indexed: 11/18/2022]
Abstract
Consumption of seafood containing the phytoplankton-derived toxin domoic acid (DOM) causes neurotoxicity in humans and in animals. It has been reported that DOM-induced symptoms may be more severe in men than women, but to date the effect of sex on DOM-induced effects in adults is not known. We investigated sex differences in DOM-induced effects in adult rats. Since low level exposure is of greatest relevance to human health (due to DOM regulatory limit), we examined the effects of low level exposure. Adult male and female Sprague Dawley rats were administered a single intraperitoneal injection of DOM (0, 1.0, 1.8 mg/kg). Behaviour was monitored for 3h and immunohistochemistry in the dorsal hippocampus and olfactory bulb was also examined. DOM increased locomotor and grooming activity, compared to vehicle group. DOM exposure also significantly increased stereotypic behaviours and decreased phosphorylated cAMP response element-binding protein immunoreactivity (pCREB-IR). There was no effect of sex on the magnitude of the behavioural responses, but the onset of DOM-induced locomotor activity and ear scratches was quicker in females than in males. Mixed effect modelling revealed the predicted peak in locomotor activity in response to DOM was also quicker in females than in males. Severe toxicity was evident in 2/7 male rats and 0/8 female rats dosed with 1.8 mg/kg DOM. These data suggest that males exposed to low level DOM may be more susceptible to severe neurotoxicity, whereas females are affected more quickly. Understanding sex differences in DOM-induced neurotoxicity may contribute to future protective strategies and treatments.
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Affiliation(s)
- Andrew W Baron
- Medical Toxicology Centre, Newcastle University, Newcastle upon Tyne NE2 4AA, UK.
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28
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Abstract
Acute Seizure (AS) activity in young adult age conspicuously modifies hippocampal neurogenesis. This is epitomized by both increased addition of new neurons to the granule cell layer (GCL) by neural stem/progenitor cells (NSCs) in the dentate subgranular zone (SGZ), and greatly enhanced numbers of newly born neurons located abnormally in the dentate hilus (DH). Interestingly, AS activity in old age does not induce such changes in hippocampal neurogenesis. However, the effect of AS activity on neurogenesis in the middle-aged hippocampus is yet to be elucidated. We examined hippocampal neurogenesis in middle-aged F344 rats after a continuous AS activity for >4 hrs, induced through graded intraperitoneal injections of the kainic acid. We labeled newly born cells via daily intraperitoneal injections of the 5'-bromodeoxyuridine (BrdU) for 12 days, commencing from the day of induction of AS activity. AS activity enhanced the addition of newly born BrdU+ cells by 5.6 fold and newly born neurons (expressing both BrdU and doublecortin [DCX]) by 2.2 fold to the SGZ-GCL. Measurement of the total number of DCX+ newly born neurons also revealed a similar trend. Furthermore, AS activity increased DCX+ newly born neurons located ectopically in the DH (2.7 fold increase and 17% of total newly born neurons). This rate of ectopic migration is however considerably less than what was observed earlier for the young adult hippocampus after similar AS activity. Thus, the plasticity of hippocampal neurogenesis to AS activity in middle age is closer to its response observed in the young adult age. However, the extent of abnormal migration of newly born neurons into the DH is less than that of the young adult hippocampus after similar AS activity. These results also point out a highly divergent response of neurogenesis to AS activity between middle age and old age.
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Affiliation(s)
- Ashok K Shetty
- Research Service, Veterans Affairs Medical Centers of Durham, North Carolina, and Temple, Texas, United States of America.
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Śmiałowska M, Gołembiowska K, Kajta M, Zięba B, Dziubina A, Domin H. Selective mGluR1 antagonist EMQMCM inhibits the kainate-induced excitotoxicity in primary neuronal cultures and in the rat hippocampus. Neurotox Res 2012; 21:379-92. [PMID: 22144346 PMCID: PMC3296950 DOI: 10.1007/s12640-011-9293-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 11/07/2011] [Accepted: 11/23/2011] [Indexed: 10/25/2022]
Abstract
Abundant evidence suggests that indirect inhibitory modulation of glutamatergic transmission, via metabotropic glutamatergic receptors (mGluR), may induce neuroprotection. The present study was designed to determine whether the selective antagonist of mGluR1 (3-ethyl-2-methyl-quinolin-6-yl)-(4-methoxy-cyclohexyl)-methanone methanesulfonate (EMQMCM), showed neuroprotection against the kainate (KA)-induced excitotoxicity in vitro and in vivo. In in vitro studies on mouse primary cortical and hippocampal neuronal cultures, incubation with KA (150 μM) induced strong degeneration [measured as lactate dehydrogenase (LDH) efflux] and apoptosis (measured as caspase-3 activity). EMQMCM (0.1-100 μM) added 30 min to 6 h after KA, significantly attenuated the KA-induced LDH release and prevented the increase in caspase-3 activity in the cultures. Those effects were dose- and time-dependent. In in vivo studies KA (2.5 nmol/1 μl) was unilaterally injected into the rat dorsal CA1 hippocampal region. Degeneration was calculated by counting surviving neurons in the CA pyramidal layer using stereological methods. It was found that EMQMCM (5-10 nmol/1 μl) injected into the dorsal hippocampus 30 min, 1 h, or 3 h (the higher dose only) after KA significantly prevented the KA-induced neuronal degeneration. In vivo microdialysis studies in rat hippocampus showed that EMQMCM (100 μM) significantly increased γ-aminobutyric acid (GABA) and decreased glutamate release. When perfused simultaneously with KA, EMQMCM substantially increased GABA release and prevented the KA-induced glutamate release. The obtained results indicate that the mGluR1 antagonist, EMQMCM, may exert neuroprotection against excitotoxicity after delayed treatment (30 min to 6 h). The role of enhanced GABAergic transmission in the neuroprotection is postulated.
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Affiliation(s)
- Maria Śmiałowska
- Department of Neurobiology, Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland.
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Sarkar S, Schmued L. In vivo administration of fluorescent dextrans for the specific and sensitive localization of brain vascular pericytes and their characterization in normal and neurotoxin exposed brains. Neurotoxicology 2012; 33:436-43. [PMID: 22525936 DOI: 10.1016/j.neuro.2012.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 03/12/2012] [Accepted: 04/08/2012] [Indexed: 11/19/2022]
Abstract
We have aimed to develop novel histochemical markers for the labeling of brain pericytes and characterize their morphology in the normal and the excitotoxin-exposed brain, as this class of cells has received little attention until recently. Pericyte labeling was accomplished by the intracerebroventricular injection of certain fluorescent dextran conjugates, such as Fluoro-Gold-dextran, FR-dextran, FITC-dextran and Fluoro-Turquoise (FT)-dextran. 1-7 days after the tracer injection, extensive labeling of vascular pericytes was seen throughout the entire brain. These cells were found distal to the endothelial cells and exhibited large dye containing vacuoles. The morphology of the pericytes was somewhat variable, exhibiting round or amoeboid shapes within larger intracellular vesicles, while those wrapping around capillaries exhibited a more elongated appearance with finger-like projections. The use of FG-dextran resulted in bluish yellow fluorescently labeled pericytes, while FR-dextran resulted in red fluorescent labeled pericytes, FITC-dextran exhibited green fluorescent pericytes and FT-dextran showed fluorescent blue pericytes in the brain. We have used these tracers to study possible changes in morphology and pericyte number following kainic acid insult, observing that the number of pericytes in the injured or lesioned areas of the brain is dramatically reduced compared to the non-injured areas. These novel fluorochromes should be of use for studies involving the detection and localization of pericytes in both normal and pathological brain tissues.
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Affiliation(s)
- Sumit Sarkar
- Division of Neurotoxicology, National Center for Toxicological Research/FDA, Jefferson, AR 72079, USA
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Imai H, Kimura A, Akiyama K, Ota C, Okimoto K, Fujiwara H. Development of a fast method for quantitative measurement of hyperpolarized 129Xe dynamics in mouse brain. NMR Biomed 2012; 25:210-217. [PMID: 21755553 DOI: 10.1002/nbm.1733] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Revised: 03/23/2011] [Accepted: 03/24/2011] [Indexed: 05/31/2023]
Abstract
A fast method has been established for the precise measurement and quantification of the dynamics of hyperpolarized (HP) xenon-129 ((129)Xe) in the mouse brain. The key technique is based on repeatedly applying radio frequency (RF) pulses and measuring the decrease of HP (129)Xe magnetization after the brain Xe concentration has reached a steady state due to continuous HP (129)Xe ventilation. The signal decrease of the (129)Xe nuclear magnetic resonance (NMR) signal was well described by a simple theoretical model. The technique made it possible to rapidly evaluate the rate constant α, which is composed of cerebral blood flow (CBF), the partition coefficient of Xe between the tissue and blood (λ(i)), and the longitudinal relaxation time (T(1i)) of HP (129)Xe in the brain tissue, without any effect of depolarization by RF pulses and the dynamics in the lung. The technique enabled the precise determination of α as 0.103 ± 0.018 s(-1) (± SD, n = 5) on healthy mice. To investigate the potential of this method for detecting physiological changes in the brain of a kainic acid (KA) -induced mouse model of epilepsy, an attempt was made to follow the time course of α after KA injection. It was found that the α value changes characteristically with time, reflecting the change in the physiological state of the brain induced by KA injection. By measuring CBF using (1)H MRI and (129)Xe dynamics simultaneously and comparing these results, it was suggested that the reduction of T(1i), in addition to the increase of CBF due to KA-induced epilepsy, are possible causes of the change in (129)Xe dynamics. Thus, the present method would be useful to detect a pathophysiological state in the brain and provide a novel tool for future brain study.
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Affiliation(s)
- Hirohiko Imai
- Department of Medical Physics and Engineering, Area of Medical Technology and Science, Division of Health Sciences, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita, Osaka, 565-0871, Japan
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Kirschman LT, Borysiewicz E, Fil D, Konat GW. Peripheral immune challenge with dsRNA enhances kainic acid-induced status epilepticus. Metab Brain Dis 2011; 26:91-3. [PMID: 21305346 DOI: 10.1007/s11011-011-9236-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 01/21/2011] [Indexed: 10/18/2022]
Abstract
Clinical evidence implicates peripheral inflammatory diseases as comorbid factors in epilepsy. The present study was designed to determine the effect of the acute phase of antiviral response on seizure susceptibility. Young adult mice were intraperitoneally injected with 12 mg/kg of a viral mimic, polyinosinic:polycytidylic acid (PIC). After 48 h, seizures were induced by subcutaneous injection of kainic acid (KA). PIC-pretreatment profoundly enhances vulnerability to excitotoxic insult as evidenced by increased seizure intensity and extended duration of status epilepticus. These results support the notion that peripheral viral infections may alter brain function resulting in enhanced predilection to seizures.
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Affiliation(s)
- Lindsay T Kirschman
- Department of Neurobiology and Anatomy, West Virginia University School of Medicine, 4052 HSCN, P.O. Box 9128, Morgantown, WV 26506-9128, USA
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Schauwecker PE. Galanin receptor 1 deletion exacerbates hippocampal neuronal loss after systemic kainate administration in mice. PLoS One 2010; 5:e15657. [PMID: 21179451 PMCID: PMC3001489 DOI: 10.1371/journal.pone.0015657] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Accepted: 11/19/2010] [Indexed: 11/30/2022] Open
Abstract
Background Galanin is a neuropeptide with a wide distribution in the central and peripheral nervous systems and whose physiological effects are mediated through three G protein-coupled receptor subtypes, GalR1, GalR2, and GalR3. Several lines of evidence indicate that galanin, as well as activation of the GalR1 receptor, is a potent and effective modulator of neuronal excitability in the hippocampus. Methodology/Principal Findings In order to test more formally the potential influence of GalR1 on seizure-induced excitotoxic cell death, we conducted functional complementation tests in which transgenic mice that exhibit decreased expression of the GalR1 candidate mRNA underwent kainate-induced status epilepticus to determine if the quantitative trait of susceptibility to seizure-induced cell death is determined by the activity of GalR1. In the present study, we report that reduction of GalR1 mRNA via null mutation or injection of the GalR1 antagonist, galantide, prior to kainate-induced status epilepticus induces hippocampal damage in a mouse strain known to be highly resistant to kainate-induced neuronal injury. Wild-type and GalR1 knockout mice were subjected to systemic kainate administration. Seven days later, Nissl and NeuN immune- staining demonstrated that hippocampal cell death was significantly increased in GalR1 knockout strains and in animals injected with the GalR1 antagonist. Compared to GalR1-expressing mice, GalR1-deficient mice had significantly larger hippocampal lesions after status epilepticus. Conclusions/Significance Our results suggest that a reduction of GalR1 expression in the C57BL/6J mouse strain renders them susceptible to excitotoxic injury following systemic kainate administration. From these results, GalR1 protein emerges as a new molecular target that may have a potential therapeutic value in modulating seizure-induced cell death.
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Affiliation(s)
- P Elyse Schauwecker
- Department of Cell and Neurobiology, University of Southern California Keck School of Medicine, Los Angeles, California, United States of America.
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Bakke MJ, Hustoft HK, Horsberg TE. Subclinical effects of saxitoxin and domoic acid on aggressive behaviour and monoaminergic turnover in rainbow trout (Oncorhynchus mykiss). Aquat Toxicol 2010; 99:1-9. [PMID: 20409597 DOI: 10.1016/j.aquatox.2010.03.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 03/03/2010] [Accepted: 03/23/2010] [Indexed: 05/29/2023]
Abstract
The algal produced neurotoxins saxitoxin and domoic acid may have serious effects on marine life and can be responsible for the intoxication of for instance sea mammals, sea birds and fish. Given that farmed fish cannot escape algal blooms, they may be more susceptible to intoxication than wild stocks. In the present study, subclinical effects of saxitoxin and domoic on aggressive behaviour and monoaminergic systems in the brain of the rainbow trout (Oncorhynchus mykiss) were investigated. The resident-intruder test was used to measure aggression where only the resident fish were subjected to the toxins and analysed for monoamines and their metabolites. The resident-intruder test was carried out on two consecutive days. On day one basal aggression was measured in the four groups. On day two three of the groups were injected with subclinical doses of one of the following: saxitoxin (1.752 microg/kg bw), domoic (0.75 mg/kg bw) or 0.9% saline solution. This was performed 30 min prior to the aggression test. Handling stress and injection affected aggressive behaviour, cortisol and the serotonergic system in telencephalic brain regions. Cortisol levels were elevated in all of the injected groups when compared to the control group. An increase in serotonergic turnover was evident when all injected groups were pooled and compared to the control group. All together this suggests that the handling stress in connection with the injection was similar in all of the three injected groups. In contrast to both the undisturbed control group and the toxin-injected groups, the saline-injected group displayed a reduction in aggressive behaviour which was evident in increased attack latency. Furthermore the domoic injected group displayed more aggressive attacks towards their conspecifics than the saline-injected group. Consequently the two toxins appear to mask the stress induced alteration in aggressive behaviour. Monoamine levels and monoaminergic turnover could not be demonstrated to be directly affected by the two toxins at the given doses in the investigated brain regions (dorsal and ventral parts of telencephalon, optic tectum, locus coeruleus, raphe nucleus, molecular and granular layer of cerebellum). This could indicate that the toxins mediate aggressive behaviour either through other systems than the monoaminergic systems, such as neuroactive amino acids, or that the mediation occurs in other brain regions.
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Affiliation(s)
- Marit Jørgensen Bakke
- Department of Pharmacology and Toxicology, Norwegian School of Veterinary Science, N-0033 Oslo, Norway.
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Fritsch B, Stott JJ, Donofrio JJ, Rogawski MA. Treatment of early and late kainic acid-induced status epilepticus with the noncompetitive AMPA receptor antagonist GYKI 52466. Epilepsia 2010; 51:108-17. [PMID: 19682025 PMCID: PMC4535693 DOI: 10.1111/j.1528-1167.2009.02205.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE Benzodiazepines such as diazepam may fail to effectively treat status epilepticus because benzodiazepine-sensitive GABA(A) receptors are progressively internalized with continued seizure activity. Ionotropic glutamate receptors, including AMPA receptors, are externalized, so that AMPA receptor antagonists, which are broad-spectrum anticonvulsants, could be more effective treatments for status epilepticus. We assessed the ability of the noncompetitive AMPA receptor antagonist GYKI 52466 to protect against kainic acid-induced status epilepticus in mice. METHODS Groups of animals treated with kainic acid received GYKI 52466 (50 mg/kg followed in 15 min by 50 mg/kg) or diazepam (25 mg/kg followed in 20 min by 12.5 mg/kg) beginning at 5 min of continuous seizure activity or 25 min later. The duration of seizure activity was determined by EEG recording from epidural cortical electrodes. RESULTS Both GYKI 52466 and diazepam rapidly terminated electrographic and behavioral seizures when administered early. However, diazepam-treated animals exhibited more seizure recurrences. With late administration, GYKI 52466 also rapidly terminated seizures and they seldom recurred, whereas diazepam was slow to produce seizure control and recurrences were common. Although both treatments caused sedation, GYKI 52466-treated animals retained neurological responsiveness whereas diazepam-treated animals did not. GYKI 52466 did not affect blood pressure whereas diazepam caused a sustained drop in mean arterial pressure. DISCUSSION Noncompetitive AMPA receptor antagonists represent a promising approach for early treatment of status epilepticus; they may also be effective at later times when there is refractoriness to benzodiazepines.
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Affiliation(s)
- Brita Fritsch
- Epilepsy Research Section, National Institute for Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A
- Department of Neurology, University of Freiburg, Freiburg, Germany
| | - Jeffrey J. Stott
- Epilepsy Research Section, National Institute for Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A
| | - Joy Joelle Donofrio
- Epilepsy Research Section, National Institute for Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A
| | - Michael A. Rogawski
- Epilepsy Research Section, National Institute for Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, California, U.S.A
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Abstract
Posttranslational modification by small ubiquitin-like modifier (SUMO) proteins is emerging as an important regulatory mechanism for neuronal function and dysfunction. Although multiple potential presynaptic SUMOylation substrate proteins have been proposed from sequence analysis the functional consequences of presynaptic SUMOylation have not been determined. Here we show that SUMOylation of presynaptic proteins modulates neurotransmitter release. Increasing protein SUMOylation by entrapping recombinant SUMO-1 in synaptosomes decreased glutamate release evoked by KCl whereas decreasing SUMOylation with the SUMO-specific protease SENP-1 enhanced KCl-evoked release. In contrast, SUMO increased and SENP-1 decreased synaptosomal glutamate release evoked by kainate stimulation. Consistent with these results, SENP-1 increased Ca(2+) influx into synaptosomes evoked by KCl whereas it decreased kainate-induced Ca(2+) influx. These results demonstrate that, in addition to postsynaptic effects, protein SUMOylation acts to modulate neurotransmitter release and thereby regulate synaptic function.
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Affiliation(s)
- Marco Feligioni
- Department of Anatomy, MRC Centre for Synaptic Plasticity, School of Medical Sciences, University of Bristol, Bristol, UK.
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Li P, Tjen-A-Looi SC, Guo ZL, Fu LW, Longhurst JC. Long-loop pathways in cardiovascular electroacupuncture responses. J Appl Physiol (1985) 2009; 106:620-30. [PMID: 19074569 PMCID: PMC2644252 DOI: 10.1152/japplphysiol.91277.2008] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Accepted: 12/09/2008] [Indexed: 11/22/2022] Open
Abstract
We have shown that electroacupuncture (EA) at P 5-6 (overlying median nerves) activates arcuate (ARC) neurons, which excite the ventrolateral periaqueductal gray (vlPAG) and inhibit cardiovascular sympathoexcitatory neurons in the rostral ventrolateral medulla (rVLM). To investigate whether the ARC inhibits rVLM activity directly or indirectly, we stimulated the splanchnic nerve to activate rVLM neurons. Micropipettes were inserted in the rVLM, vlPAG, and ARC for neural recording or injection. Microinjection of kainic acid (KA; 1 mM, 50 nl) in the ARC blocked EA inhibition of the splanchnic nerve stimulation-induced reflex increases in rVLM neuronal activity. Microinjection of d,l-homocysteic acid (4 nM, 50 nl) in the ARC, like EA, inhibited reflex increases in the rVLM neuronal discharge. The vlPAG neurons receive convergent input from the ARC, splanchnic nerve, P 5-6, and other acupoints. Microinjection of KA bilaterally into the rostral vlPAG partially reversed rVLM neuronal responses and cardiovascular inhibition during d,l-homocysteic acid stimulation of the ARC. On the other hand, injection of KA into the caudal vlPAG completely reversed these responses. We also observed that ARC neurons could be antidromically activated by stimulating the rVLM, and that ARC perikarya was labeled with retrograde tracer that had been microinjected into the rVLM. These neurons frequently contained beta-endorphin and c-Fos, activated by EA stimulation. Therefore, the vlPAG, particularly, the caudal vlPAG, is required for ARC inhibition of rVLM neuronal activation and subsequent EA-related cardiovascular activation. Direct projections from the ARC to the rVLM, which serve as an important source of beta-endorphin, appear also to exist.
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Affiliation(s)
- Peng Li
- Department of Medicine, University of California, Irvine, CA, USA.
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Kipiani E. OLM interneurons are transiently recruited into field gamma oscillations evoked by brief kainate pressure ejections onto area CA1 in mice hippocampal slices. Georgian Med News 2009:63-68. [PMID: 19276474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Oscillations (30-100 Hz) are correlated with the cognitive functions of the brain. In the hippocampus interactions between perisomatic and trilaminar interneurons with pyramidal cells are thought to underlie generation of field gamma oscillations. In area CA3 OLM interneurons receive synaptic input in gamma range but generate action potential (AP) output in theta band and are involved in theta oscillations synchronized along the longitudinal axis of the hippocampus. In slice preparations of CA3 area the spike timing of OLM cells could be modulated by carbachole induced gamma oscillations, although their firing rates are limited to theta frequency. Normally, OLM interneurons are somatostatin positive cells. In this study we tested whether parvalbumin (PV) containing OLM interneurons in area CA1 limit AP output during kainate pressure ejection also to theta frequency. We used focal short applications of kainate in area CA1 to induce filed gamma oscillations with an average frequency of about 44.7+/-4.4 Hz. The duration of field gamma was on average 8.9+/-3.5 s. During such oscillations CA1 PV positive OLM interneurons of mice hippocampus received excitatory synaptic input at gamma frequency. Moreover, their AP output was in gamma range as well. Thus, we show that beside the somatostatin containing OLM interneurons, which generate theta rhythm there are PV containing OLM cells, which could synchronize the distal dendrites of CA1 pyramidal cells to the field gamma oscillations.
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Affiliation(s)
- E Kipiani
- Johannes Müller-Center for Physiology, Institute for Neurophysiology, Charité - Universitätsmedizin Berlin, Germany
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Kramer MA, Roopun AK, Carracedo LM, Traub RD, Whittington MA, Kopell NJ. Rhythm generation through period concatenation in rat somatosensory cortex. PLoS Comput Biol 2008; 4:e1000169. [PMID: 18773075 PMCID: PMC2518953 DOI: 10.1371/journal.pcbi.1000169] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Accepted: 07/29/2008] [Indexed: 11/18/2022] Open
Abstract
Rhythmic voltage oscillations resulting from the summed activity of neuronal populations occur in many nervous systems. Contemporary observations suggest that coexistent oscillations interact and, in time, may switch in dominance. We recently reported an example of these interactions recorded from in vitro preparations of rat somatosensory cortex. We found that following an initial interval of coexistent gamma ( approximately 25 ms period) and beta2 ( approximately 40 ms period) rhythms in the superficial and deep cortical layers, respectively, a transition to a synchronous beta1 ( approximately 65 ms period) rhythm in all cortical layers occurred. We proposed that the switch to beta1 activity resulted from the novel mechanism of period concatenation of the faster rhythms: gamma period (25 ms)+beta2 period (40 ms) = beta1 period (65 ms). In this article, we investigate in greater detail the fundamental mechanisms of the beta1 rhythm. To do so we describe additional in vitro experiments that constrain a biologically realistic, yet simplified, computational model of the activity. We use the model to suggest that the dynamic building blocks (or motifs) of the gamma and beta2 rhythms combine to produce a beta1 oscillation that exhibits cross-frequency interactions. Through the combined approach of in vitro experiments and mathematical modeling we isolate the specific components that promote or destroy each rhythm. We propose that mechanisms vital to establishing the beta1 oscillation include strengthened connections between a population of deep layer intrinsically bursting cells and a transition from antidromic to orthodromic spike generation in these cells. We conclude that neural activity in the superficial and deep cortical layers may temporally combine to generate a slower oscillation.
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Affiliation(s)
- Mark A Kramer
- Department of Mathematics and Statistics, Boston University, Boston, Massachusetts, United States of America.
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Abstract
The protective effect of topiramate (TPM) on seizure-induced neuronal injury is well known; however, its molecular basis has yet to be elucidated. We investigated the effect and signaling mediators of TPM on seizure-induced hippocampal cell death in kainic acid (KA)-treated ICR mice. KA-induced hippocampal cell death was identified by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. Immunoreactivity (IR) of p-Erk, p-Jnk, p-P38, and caspase-3, and caspase-3 activity were observed in the hippocampal region 3 h after KA (0.1 microg/5 microL, i.c.v.) administration, and/or TPM (100 mg/kg, i.p.) pretreatment. TPM attenuated seizure-induced neuronal cell death and reduced KA-induced p-Erk IR in the CA3 region of the hippocampus, but did not affect p-Jnk and p-P38. In addition, TPM reduced caspase-3 IR and activation by KA. KA-induced seizures were also suppressed by TPM pretreatment. TPM inhibits seizures, and decreases Erk phosphorylation and caspase-3 activation by KA, thereby contributing to protection from neuronal injury.
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Affiliation(s)
- Hae Jeong Park
- Department of Pharmacology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
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Bakke MJ, Horsberg TE. Effects of algal-produced neurotoxins on metabolic activity in telencephalon, optic tectum and cerebellum of Atlantic salmon (Salmo salar). Aquat Toxicol 2007; 85:96-103. [PMID: 17870190 DOI: 10.1016/j.aquatox.2007.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 08/07/2007] [Accepted: 08/08/2007] [Indexed: 05/17/2023]
Abstract
Neurotoxins from algal blooms have been reported to cause mortality in a variety of species, including sea birds, sea mammals and fish. Farmed fish cannot escape harmful algal blooms and their potential toxins, thus they are more vulnerable for exposure than wild stocks. Sublethal doses of the toxins are likely to affect fish behaviour and may impair cognitive abilities. In the present study, changes in the metabolic activity in different parts of the Atlantic salmon (Salmo salar) brain involved in central integration and cognition were investigated after exposure to sublethal doses of three algal-produced neurotoxins; saxitoxin (STX), brevetoxin (BTX) and domoic acid (DA). Fish were randomly selected to four groups for i.p. injection of saline (control) or one of the neurotoxins STX (10 microg STX/kg bw), BTX (68 microg BTX/kg bw) or DA (6 mg DA/kg bw). In addition, 14C-2-deoxyglucose was i.m. injected to measure brain metabolic activity by autoradiography. The three regions investigated were telencephalon (Tel), optic tectum (OT) and cerebellum (Ce). There were no differences in the metabolic activity after STX and BTX exposure compared to the control in these regions. However, a clear increase was observed after DA exposure. When the subregions with the highest metabolic rate were pseudocoloured in the three brain regions, the three toxins caused distinct differences in the respective patterns of metabolic activation. Fish exposed to STX displayed similar patterns as the control fish, whereas fish exposed to BTX and DA showed highest metabolic activity in subregions different from the control group. All three neurotoxins affected subregions that are believed to be involved in cognitive abilities in fish.
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Affiliation(s)
- Marit Jørgensen Bakke
- Department of Pharmacology and Toxicology, Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033 Oslo, Norway
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Tiedeken JA, Ramsdell JS. Embryonic exposure to domoic Acid increases the susceptibility of zebrafish larvae to the chemical convulsant pentylenetetrazole. Environ Health Perspect 2007; 115:1547-52. [PMID: 18007982 PMCID: PMC2072828 DOI: 10.1289/ehp.10344] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Accepted: 08/02/2007] [Indexed: 05/20/2023]
Abstract
BACKGROUND Domoic acid (DA) is a neurotoxin produced by diatoms of the genus Pseudo-nitzschia that targets the limbic system to induce tonic-clonic seizures and memory impairment. In utero DA exposure of mice leads to a reduction in seizure threshold to subsequent DA exposures in mid-postnatal life, and similar studies have shown neurotoxic effects in rats that were delayed until adolescence. OBJECTIVE We used in ovo microinjection of zebrafish (Danio rerio) to characterize the effect of embryonic exposure of DA on seizure-inducing agents later in life as an alternative species model to screen environmental contaminants that might induce a fetal-originating adult disease. METHODS Embryos were microinjected within hours of fertilization to DA concentrations ranging from 0.12 to 1.26 ng/mg egg weight. Seven days later, the larval animals were characterized for sensitivity to the chemical convulsant pentylenetetrazole (PTZ), an agent that is well-defined in laboratory rodents and, more recently, in zebrafish. RESULTS In ovo DA exposure, most significantly at 0.4 ng/mg, reduces the latency time until first PTZ seizure in larval fish and increases the severity of seizures as determined by seizure stage and movement parameters. The interaction between in ovo DA exposure and PTZ caused seizure behaviors to individually asymptomatic doses of PTZ (1.0 and 1.25 mM) and DA (0.13 and 0.22 ng/mg). CONCLUSION These studies demonstrate that in ovo exposure to DA reduces the threshold to chemically induced seizures in larval fish and increases the severity of seizure behavior in a manner that is consistent with in utero studies of laboratory rodents.
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Affiliation(s)
| | - John S. Ramsdell
- Address correspondence to J.S. Ramsdell, Center for Coastal Environmental Health and Biomolecular Research, 219 Fort Johnson Rd., Charleston, SC 29412 USA. Telephone: (843) 762-8910. Fax: (843) 762-8700. E-mail:
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Arkhipov VI, Sirota TV, Lebedev DS. [Effect of intrahippocampal kainic acid on the behavior of rats and functional state of mitochondria in brain structures]. Izv Akad Nauk Ser Biol 2007:570-576. [PMID: 18038624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Cognitive processes and functional state of mitochondria in brain structures of Wistar rats were studied after intrahippocampal injection of kainic acid, an agonist of glutamate receptors. A single administration of 0.25 microg kainic acid into the dorsal part of the left and right hippocampi affected task retrieval and decreased inhibition of unrewarded responses. The injection of 0.75 microg kainic acid induced recurrent seizures and completely disorganized animal behavior. The functional state of mitochondria, as an important marker of excitotoxicity, was studied after intrahippocampal injections of kainic acid in the same doses. Kainic acid at 0.25 microg proved to activate the oxidative phosphorylation in hippocampal mitochondria. A higher (epileptogenic) dose of kainic acid inhibited mitochondrial respiration in the frontal cortex, but had an insignificant effect on mitochondrial respiration in the hippocampus. The disturbed interaction between the hippocampal system and frontal cortex after kainic acid administration can be the main factor of the revealed cognitive dysfunctions.
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Tomczyk T, Haberek G, Zuchora B, Jarosławska-Zych A, Kowalczyk MS, Wielosz M, Urbańska EM. Enhanced glutamatergic transmission reduces the anticonvulsant potential of lamotrigine but not of felbamate against tonic-clonic seizures. Pharmacol Rep 2007; 59:462-6. [PMID: 17901576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2007] [Revised: 08/21/2007] [Indexed: 05/17/2023]
Abstract
The efficacy of lamotrigine and felbamate against maximal electroshock (MES)-induced seizures was assessed under conditions mimicking the pharmacoresistance associated with an increased excitatory neurotransmission. N-methyl-D-aspartate (NMDA), but not kainate applied at subconvulsive dose, reduced the activity of lamotrigine against MES-induced seizures increasing its ED50 value from 4.3 (3.2-5.6) to 6.1 (5.2-7.2) mg/kg (p < 0.001). This effect was reversed by co-application of an NMDAreceptor antagonist D-(E)-2-amino-4-methyl-5-phosphono-3-pentenoic acid (CGP 40116) at 0.1 mg/kg [4.5 (3.7-5.6) vs. 6.1 (5.2-7.2) mg/kg; p < 0.001]. The anticonvulsive action of felbamate was altered by neither NMDAnor kainate. In conclusion, the data presented here indicate that felbamate, but not lamotrigine, effectively prevents generalized tonic-clonic seizures, also when NMDA-mediated neurotransmission is enhanced. The impaired antiepileptic potential of lamotrigine might be restored in such scenario by the co-administration of a very low dose of NMDA receptor antagonist.
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Affiliation(s)
- Tomasz Tomczyk
- Department of Pharmacology and Clinical Pharmacology, Skubiszewski Medical University of Lublin, Jaczewskiego 8, PL 20-090 Lublin, Poland
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Broberg M, Pope KJ, Nilsson M, Wallace A, Wilson J, Willoughby JO. Preseizure increased gamma electroencephalographic activity has no effect on extracellular potassium or calcium. J Neurosci Res 2007; 85:906-18. [PMID: 17243172 DOI: 10.1002/jnr.21162] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Extracellular ion concentrations change during seizures in seizure models. [K(+)](o) increases and [Ca(2+)](o) decreases, resulting from population discharges, enhanced neuronal excitability, though not obviously before seizure onset. In acute pharmacological epilepsy models, there are striking increases in preictal high-frequency (gamma) electroencephalographic (EEG) activity. It is not known whether enhanced gamma EEG results in ionic changes, because gamma and ions have not been measured simultaneously. In this study, unanesthetized, paralyzed rats were given intravenous injections of kainic acid or picrotoxin to induce EEG discharges. Changes in EEG, [K(+)](o), and [Ca(2+)](o) in cortex and hippocampus were recorded. Kainic acid caused small [K(+)](o) fluctuations, without a temporal relationship of these with increased gamma EEG or with onset of discharges. Gamma EEG increases after picrotoxin also failed to affect [K(+)](o) and [Ca(2+)](o). Picrotoxin-induced electrical discharges led to [K(+)](o) rises of >9 mM and [Ca(2+)](o) falls of 0.1-0.2 mM. Kainic acid-induced discharges generated only moderate (2-3 mM) rises in [K(+)](o) and no changes in [Ca(2+)](o). In both models, there were large potassium rises (15-80 mM) and calcium falls (>0.5 mM), suggesting spreading depressions. Small [K(+)](o) fluctuations after kainic acid are consistent with disruption in potassium homeostasis, possibly because of depolarization of astrocytes. To reveal possible latent [K(+)](o) or [Ca(2+)](o) changes, we injected fluorocitrate intracortically to impair astrocytic function, before administering picrotoxin. Even fluorocitrate did not cause gamma-related ion changes but did cause low-magnitude, transient, potassium increases and slower potassium homeostasis during discharges, minor changes consistent with involvement of both astrocytes and neurons in [K(+)](o) regulation. (c) 2007 Wiley-Liss, Inc.
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Affiliation(s)
- Marita Broberg
- Center for Neuroscience and Department of Medicine, Flinders University, Adelaide, South Australia, Australia
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Shim EJ, Seo YJ, Kwon MS, Ham YO, Choi OS, Lee JY, Choi SM, Suh HW. The intracerebroventricular kainic acid-induced damage affects animal nociceptive behavior. Brain Res Bull 2007; 73:203-9. [PMID: 17562385 DOI: 10.1016/j.brainresbull.2007.02.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 12/25/2006] [Accepted: 02/13/2007] [Indexed: 01/05/2023]
Abstract
In the present study, we examined nociceptive behaviors on various pain models after the pretreatment of kainic acid intracerebroventricularly. We found that intracerebroventricular administration of kainic acid shows significant neuronal damage on the hippocampal CA3 region in the brain slices stained with cresyl violet. Compared to the control group, intracerebroventricular pretreatment of kainic acid significantly attenuated nocifensive behaviors induced by intraplantar formalin (only in the 2nd phase), intrathecal glutamate, TNF-alpha or IL-1beta. However, nocifensive behaviors induced by intraperitoneal acetic acid (writhing test), intrathecal substance P or IFN-gamma were not affected by the pretreatment of kainic acid. These results suggest that (1) KA-induced alterations of nocifensive behaviors are related to the neuronal death of the hippocampal formation, especially CA3 pyramidal neurons and (2) nocifensive behaviors induced by formalin, acetic acid, SP, glutamate, and pro-inflammatory cytokines were modulated in a different manner.
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Affiliation(s)
- Eon-Jeong Shim
- Department of Pharmacology, Institute of Natural Medicine, College of Medicine, Hallym University, 1 Okchun-Dong, ChunCheon, Gangwon-Do 200-702, South Korea
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Lefebvre KA, Noren DP, Schultz IR, Bogard SM, Wilson J, Eberhart BTL. Uptake, tissue distribution and excretion of domoic acid after oral exposure in coho salmon (Oncorhynchus kisutch). Aquat Toxicol 2007; 81:266-74. [PMID: 17250904 DOI: 10.1016/j.aquatox.2006.12.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 12/18/2006] [Accepted: 12/18/2006] [Indexed: 05/13/2023]
Abstract
Domoic acid (DA) is a potent neurotoxin naturally produced by some pennate diatom species of the genus Pseudo-nitzschia. It is well known that during harmful algal blooms fish can accumulate DA in the gastrointestinal (GI) tract and act as vectors of the toxin to higher trophic level piscivores, often with severe neurotoxic consequences to the predators. Although neurotoxicity and mass mortality have been observed in vertebrates (i.e. marine mammals and sea birds) feeding on contaminated fish, to date there has been no evidence of neurobehavioral toxicity in the fish vectors themselves. It has been hypothesized that fish may not absorb DA from the digestive tract, thus making them insensitive to dietary consumption of DA. To test this hypothesis, we performed oral gavage exposures followed by a time series of tissue dissections to characterize uptake, depuration, and tissue distribution of DA in fish. Intracoelomic (IC) injection exposures (which bypass the GI tract) were also performed to determine if coho neurons are neurologically susceptible to DA. Excitotoxic symptoms were observed in fish via IC injection at similar toxin levels that have been reported to induce excitotoxic symptoms in intraperitoneal (IP) exposures with mammalian models such as mice, suggesting that fish neurons have a similar sensitivity to DA as other vertebrates. Surprisingly, after oral gavage with ecologically relevant doses of DA, the toxin was detected in plasma collected from the dorsal aorta via a permanent intraarterial catheter within 15 min, yet excitotoxic symptoms were not observed. Additionally, DA was detected in liver, heart, spleen, kidney, muscle, brain and bile. These data indicate that although DA is absorbed from the gut, fish do not exhibit neuroexcitatory effects at maximum ecologically relevant oral doses of DA. Tissue distribution and DA uptake and depuration patterns suggest that a majority of the absorbed toxin is excreted via the kidneys and bile, thereby preventing toxic levels of DA from reaching sensitive nervous tissue. Additionally, greater than 20% of total IC administered DA doses were sequestered in bile within 1h of injection in five symptomatic fish, providing evidence for biliary sequestration of the toxin from blood. Here, we comprehensively describe the uptake, depuration, and tissue distribution patterns of DA and propose that renal and biliary processes may serve as primary routes of toxin clearance in fish.
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Affiliation(s)
- Kathi A Lefebvre
- NOAA Fisheries, Northwest Fisheries Science Center, Environmental Conservation Division, Marine Biotoxins Program, 2725 Montlake Blvd. East, Seattle, WA 98112, USA.
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Borges K, Shaw R, Dingledine R. Gene expression changes after seizure preconditioning in the three major hippocampal cell layers. Neurobiol Dis 2007; 26:66-77. [PMID: 17239605 PMCID: PMC2295285 DOI: 10.1016/j.nbd.2006.12.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 10/31/2006] [Accepted: 12/05/2006] [Indexed: 12/23/2022] Open
Abstract
Rodents experience hippocampal damage after status epilepticus (SE) mainly in pyramidal cells while sparing the dentate granule cell layer (DGCL). Hippocampal damage was prevented in rats that had been preconditioned by brief seizures on 2 consecutive days before SE. To identify neuroprotective genes and biochemical pathways changed after preconditioning we compared the effect of preconditioning on gene expression in the CA1 and CA3 pyramidal and DGCLs, harvested by laser capture microscopy. In the DGCL the expression of 632 genes was altered, compared to only 151 and 58 genes in CA1 and CA3 pyramidal cell layers. Most of the differentially expressed genes regulate tissue structure and intra- and extracellular signaling, including neurotransmission. A selective upregulation of energy metabolism transcripts occurred in CA1 pyramidal cells relative to the DGCL. These results reveal a broad transcriptional response of the DGCL to preconditioning, and suggest several mechanisms underlying the neuroprotective effect of preconditioning seizures.
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Affiliation(s)
- Karin Borges
- Department of Pharmacology, School of Medicine, 1510 Clifton Rd, Emory University, Atlanta, GA 30322, USA.
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Riljak V, Milotová M, Jandová K, Pokorný J, Langmeier M. Morphological changes in the hippocampus following nicotine and kainic acid administration. Physiol Res 2007; 56:641-649. [PMID: 17223731 DOI: 10.33549/physiolres.931048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Using histochemical analysis (NADPH-diaphorase, Fluoro-Jade B dye and bis-benzimide 33,342 Hoechst) we studied the influence of intraperitoneal administration of nicotine (NIC), kainic acid (KA) and combination of both these substances on hippocampal neurons and their changes. In experiments, 35-day-old male rats of the Wistar strain were used. Animals were pretreated with 1 mg/kg of nicotine 30 min prior to the kainic acid application (10 mg/kg). After two days, the animals were transcardially perfused with 4 % paraformaldehyde under deep thiopental anesthesia. Cryostat sections were stained to identify NADPH-diaphorase positive neurons that were then quantified in the CA1 and CA3 areas of the hippocampus, in the dorsal and ventral blades of the dentate gyrus and in the hilus of the dentate gyrus. Fluoro-Jade B positive cells were examined in the same areas in order to elucidate a possible neurodegeneration. In animals exposed only to nicotine the number of NADPH-diaphorase positive neurons in the CA3 area of the hippocampus and in the hilus of the dentate gyrus was higher than in controls. In contrast, KA administration lowered the number of NADPH-diaphorase positive cells in all studied hippocampal areas and in both blades of the dentate gyrus. Massive cell degeneration was observed in CA1 and CA3 areas of the hippocampus and in the hilus of the dentate gyrus after kainic acid administration. Animals exposed to kainic acid and pretreated with nicotine exhibited degeneration to a lesser extent and the number of NADPH-diaphorase positive cells was higher compared to rats, which were exposed to kainic acid only.
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Affiliation(s)
- V Riljak
- Institute of Physiology, First Faculty of Medicine, Charles University, Prague, Czech Republic.
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Bishnoi M, Patil CS, Kumar A, Kulkarni SK. Co-Administration of Acetyl-11-Keto-β-Boswellic Acid, a Specific 5-Lipoxygenase Inhibitor, Potentiates the Protective Effect of COX-2 Inhibitors in Kainic Acid-Induced Neurotoxicity in Mice. Pharmacology 2006; 79:34-41. [PMID: 17139192 DOI: 10.1159/000097627] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2006] [Accepted: 09/20/2006] [Indexed: 11/19/2022]
Abstract
Cyclooxygenase (COX) and lipoxygenase (LOX) are responsible for the metabolism of arachidonic acid into inflammatory metabolites, prostaglandins and leukotrienes, respectively. The upregulation of these enzymes in the central nervous system has been demonstrated to be responsible for the increased neuronal vulnerability to degeneration. Kainic acid, a glutamate receptor agonist and responsible for neuronal excitotoxicity and oxidative damage via different mechanisms, is capable of stimulating mRNA of both COX-2 and 5-LOX in the brain. The present study was designed to study the effects of COX inhibitors (indomethacin, nimesulide, rofecoxib) and a 5-LOX inhibitor (acetyl-11-keto-beta-boswellic acid; AKBA) and the combination of these inhibitors (dual inhibition) on kainic acid induced excitotoxicity and oxidative and nitrosative damage in mice. The results from the present study indicated that AKBA, indomethacin, and nimesulide per se did not produce any change in the behavioural parameters after kainic acid administration; however, rofecoxib per seproduced a significant increase in the latency of clonic (seizure-like) movement and a decrease in mortality rate as compared with kainic acid treated animals. In combination studies AKBA, rofecoxib, and nimesulide produced a more pronounced effect than either of these drugs alone. Further, the effect of AKBA combined with rofecoxib was significantly more marked when compared with AKBA combined with nimesulide. Besides this, identical results were found for the effect of these agents and their combination against oxidative damage induced by kainic acid. These findings indicate the potential role of COX-2 inhibitors and also their combination with the 5-LOX inhibitor in kainic acid induced excitotoxicity and oxidative damage by virtue of their antioxidant effect and suggest the need for the development of dual inhibitors for the treatment of neuronal excitotoxicity.
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Affiliation(s)
- Mahendra Bishnoi
- Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
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