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Identification of a Novel Idiopathic Epilepsy Risk Locus and a Variant in the CCDC85A Gene in the Dutch Partridge Dog. Animals (Basel) 2023; 13:ani13050810. [PMID: 36899667 PMCID: PMC10000155 DOI: 10.3390/ani13050810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/15/2023] [Accepted: 02/20/2023] [Indexed: 03/12/2023] Open
Abstract
(1) Idiopathic epilepsy (IE) is thought to have a genetic cause in several dog breeds. However, only two causal variants have been identified to date, and few risk loci are known. No genetic studies have been conducted on IE in the Dutch partridge dog (DPD), and little has been reported on the epileptic phenotype in this breed. (2) Owner-filled questionnaires and diagnostic investigations were used to characterize IE in the DPD. A genome-wide association study (GWAS) involving 16 cases and 43 controls was performed, followed by sequencing of the coding sequence and splice site regions of a candidate gene within the associated region. Subsequent whole-exome sequencing (WES) of one family (including one IE-affected dog, both parents, and an IE-free sibling) was performed. (3) IE in the DPD has a broad range in terms of age at onset, frequency, and duration of epileptic seizures. Most dogs showed focal epileptic seizures evolving into generalized seizures. A new risk locus on chromosome 12 (BICF2G630119560; praw = 4.4 × 10-7; padj = 0.043) was identified through GWAS. Sequencing of the GRIK2 candidate gene revealed no variants of interest. No WES variants were located within the associated GWAS region. However, a variant in CCDC85A (chromosome 10; XM_038680630.1: c.689C > T) was discovered, and dogs homozygous for the variant (T/T) had an increased risk of developing IE (OR: 6.0; 95% CI: 1.6-22.6). This variant was identified as likely pathogenic according to ACMG guidelines. (4) Further research is necessary before the risk locus or CCDC85A variant can be used for breeding decisions.
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2
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Marion-Poll L, Forêt B, Zielinski D, Massip F, Attia M, Carter AC, Syx L, Chang HY, Gendrel AV, Heard E. Locus specific epigenetic modalities of random allelic expression imbalance. Nat Commun 2021; 12:5330. [PMID: 34504093 PMCID: PMC8429725 DOI: 10.1038/s41467-021-25630-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 08/19/2021] [Indexed: 01/02/2023] Open
Abstract
Most autosomal genes are thought to be expressed from both alleles, with some notable exceptions, including imprinted genes and genes showing random monoallelic expression (RME). The extent and nature of RME has been the subject of debate. Here we investigate the expression of several candidate RME genes in F1 hybrid mouse cells before and after differentiation, to define how they become persistently, monoallelically expressed. Clonal monoallelic expression is not present in embryonic stem cells, but we observe high frequencies of monoallelism in neuronal progenitor cells by assessing expression status in more than 200 clones. We uncover unforeseen modes of allelic expression that appear to be gene-specific and epigenetically regulated. This non-canonical allelic regulation has important implications for development and disease, including autosomal dominant disorders and opens up therapeutic perspectives.
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Affiliation(s)
- Lucile Marion-Poll
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France.
- Directors' research, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
| | - Benjamin Forêt
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France
| | - Dina Zielinski
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France
- Institut Curie, PSL Research University, INSERM U900, Mines ParisTech, Paris, France
| | - Florian Massip
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Mikael Attia
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France
| | - Ava C Carter
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA, USA
| | - Laurène Syx
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France
- Institut Curie, PSL Research University, INSERM U900, Mines ParisTech, Paris, France
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA, USA
| | - Anne-Valerie Gendrel
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France.
| | - Edith Heard
- Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, Paris, France.
- Directors' research, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
- Collège de France, Paris, France.
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The Kainic Acid Models of Temporal Lobe Epilepsy. eNeuro 2021; 8:ENEURO.0337-20.2021. [PMID: 33658312 PMCID: PMC8174050 DOI: 10.1523/eneuro.0337-20.2021] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/14/2021] [Accepted: 01/24/2021] [Indexed: 12/14/2022] Open
Abstract
Experimental models of epilepsy are useful to identify potential mechanisms of epileptogenesis, seizure genesis, comorbidities, and treatment efficacy. The kainic acid (KA) model is one of the most commonly used. Several modes of administration of KA exist, each producing different effects in a strain-, species-, gender-, and age-dependent manner. In this review, we discuss the advantages and limitations of the various forms of KA administration (systemic, intrahippocampal, and intranasal), as well as the histologic, electrophysiological, and behavioral outcomes in different strains and species. We attempt a personal perspective and discuss areas where work is needed. The diversity of KA models and their outcomes offers researchers a rich palette of phenotypes, which may be relevant to specific traits found in patients with temporal lobe epilepsy.
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Xiong S, Wang Y, Li H, Zhang X. Interaction among GRIK2 gene on epilepsy susceptibility in Chinese children. Acta Neurol Scand 2019; 139:540-545. [PMID: 30908586 DOI: 10.1111/ane.13089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/12/2019] [Accepted: 03/16/2019] [Indexed: 11/29/2022]
Abstract
AIMS The association of single nucleotide polymorphisms (SNPs) of glutamate receptor 2 (GRIK2) gene, as well as gene-gene interaction with the risk of early-onset epilepsy susceptibility, was studied in Chinese children. METHODS Generalized multi-factor dimension reduction (GMDR) is used to identify the optimal linkage between interaction among four SNPs and early-onset epilepsy susceptibility. Logistic regression was performed to assess association between four SNPs within GRIK2 gene and the risk of epilepsy. RESULTS The results show that the risk of epilepsy in the rs4840200-T allele carriers was significantly higher than CC (CT/TT vs CC), adjusted OR (95% CI) = 1.74 (1.31-2.20), and the carrier of rs3213607-A allele was also higher than CC (CG/GG vs CC) with adjusted OR (95% CI) = 1.61 (1.23-2.10). We did not detect significant association between rs9390754 and rs2235076 within GRIK2 gene and epilepsy risk. In the GMDR analysis for the gene/gene interaction (2-4 locus models), we found a significant two-locus model (P = 0.001) involving rs4840200 and rs9390754. The cross-validation consistency was 10/10, and the prediction error was 0.632. Participants with rs4840200-CT/TT and rs9390754-GA/AA genotype within GRIK2 gene have the highest epilepsy risk, compared to participants with rs4840200-CC and rs9390754-GG genotype within GRIK2 gene, OR (95% CI) = 2.42 (1.78-3.11), after covariates adjustment for age and gender. CONCLUSIONS Both rs4840200-T and rs3213607-A, and the interactions between rs4840200 and rs9390754 are related to the increased risk of epilepsy risk.
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Affiliation(s)
- Shunjun Xiong
- Department of Pediatrics, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yanjun Wang
- Department of Pediatrics, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Huijuan Li
- Department of Pediatrics, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Xiaofang Zhang
- Department of Pediatrics, Zhongnan Hospital of Wuhan University, Wuhan, China
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Chandra N, Awasthi R, Ozdogan T, Johenning FW, Imbrosci B, Morris G, Schmitz D, Barkai E. A Cellular Mechanism Underlying Enhanced Capability for Complex Olfactory Discrimination Learning. eNeuro 2019; 6:ENEURO.0198-18.2019. [PMID: 30783614 PMCID: PMC6378325 DOI: 10.1523/eneuro.0198-18.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 12/26/2018] [Accepted: 01/06/2019] [Indexed: 11/21/2022] Open
Abstract
The biological mechanisms underlying complex forms of learning requiring the understanding of rules based on previous experience are not yet known. Previous studies have raised the intriguing possibility that improvement in complex learning tasks requires the long-term modulation of intrinsic neuronal excitability, induced by reducing the conductance of the slow calcium-dependent potassium current (sIAHP) simultaneously in most neurons in the relevant neuronal networks in several key brain areas. Such sIAHP reduction is expressed in attenuation of the postburst afterhyperpolarization (AHP) potential, and thus in enhanced repetitive action potential firing. Using complex olfactory discrimination (OD) learning as a model for complex learning, we show that brief activation of the GluK2 subtype glutamate receptor results in long-lasting enhancement of neuronal excitability in neurons from controls, but not from trained rats. Such an effect can be obtained by a brief tetanic synaptic stimulation or by direct application of kainate, both of which reduce the postburst AHP in pyramidal neurons. Induction of long-lasting enhancement of neuronal excitability is mediated via a metabotropic process that requires PKC and ERK activation. Intrinsic neuronal excitability cannot be modulated by synaptic activation in neurons from GluK2 knock-out mice. Accordingly, these mice are incapable of learning the complex OD task. Moreover, viral-induced overexpression of Gluk2 in piriform cortex pyramidal neurons results in remarkable enhancement of complex OD learning. Thus, signaling via kainate receptors has a central functional role in higher cognitive abilities.
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Affiliation(s)
| | | | | | | | | | | | | | - Edi Barkai
- University of Haifa, Haifa 3498838, Israel
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Interstrain differences of ionotropic glutamate receptor subunits in the hippocampus and induction of hippocampal sclerosis with pilocarpine in mice. J Chem Neuroanat 2015; 64-65:1-11. [PMID: 25697672 DOI: 10.1016/j.jchemneu.2015.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Revised: 01/16/2015] [Accepted: 02/06/2015] [Indexed: 12/29/2022]
Abstract
Rodent strains used in epilepsy research have various neurological characteristics. These differences were suggested to be attributed to the diverse densities of the ionotropic glutamate receptor (iGluR) subunits. However, previous studies failed to find interstrain differences in the hippocampal receptor levels. We supposed that a detailed layer-to-layer analysis of the iGluR subunits in the hippocampus might reveal strain-dependent differences in their base lines and reactions induced by pilocarpine (PILO) between two mouse strains without documented ancestors. Levels of iGluR subunits in Balb/c and NMRI mice were compared using semiquantitative immunohistochemistry. The alterations in the neuronal circuitry were validated by neuropeptide Y (NPY) and neuronal nuclear antigen (NeuN) immunostainings. Immunohistochemistry showed interstrain laminar differences in some subunits of both the control and PILO-treated animals. The seizure-induced irreversible neuronal changes were accompanied by reduced GluA1 and GluA2 levels. Their changes were inversely correlated in the individual NMRI mice by Pearson's method. Increase in NPY immunoreactivity showed positive correlation with GluA1, and negative correlation with GluA2. The NMRI strain was susceptible to PILO-induced hippocampal sclerosis, while the Balb/c animals showed resistance. Basal levels of iGluRs differ in mouse strains, which may account for the interstrain differences in their reactions to the convulsant.
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Rojas DC. The role of glutamate and its receptors in autism and the use of glutamate receptor antagonists in treatment. J Neural Transm (Vienna) 2014; 121:891-905. [PMID: 24752754 PMCID: PMC4134390 DOI: 10.1007/s00702-014-1216-0] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Accepted: 04/06/2014] [Indexed: 12/11/2022]
Abstract
Glutamate is the major excitatory neurotransmitter in the brain and may be a key neurotransmitter involved in autism. Literature pertaining to glutamate and autism or related disorders (e.g., Fragile X syndrome) is reviewed in this article. Interest in glutamatergic dysfunction in autism is high due to increasing convergent evidence implicating the system in the disorder from peripheral biomarkers, neuroimaging, protein expression, genetics and animal models. Currently, there are no pharmaceutical interventions approved for autism that address glutamate deficits in the disorder. New treatments related to glutamatergic neurotransmission, however, are emerging. In addition, older glutamate-modulating medications with approved indications for use in other disorders are being investigated for re-tasking as treatments for autism. This review presents evidence in support of glutamate abnormalities in autism and the potential for translation into new treatments for the disorder.
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Affiliation(s)
- Donald C Rojas
- Department of Psychology, Campus Delivery 1876, Colorado State University, Fort Collins, CO, 80523, USA,
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Lévesque M, Avoli M. The kainic acid model of temporal lobe epilepsy. Neurosci Biobehav Rev 2013; 37:2887-99. [PMID: 24184743 DOI: 10.1016/j.neubiorev.2013.10.011] [Citation(s) in RCA: 358] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 10/16/2013] [Accepted: 10/22/2013] [Indexed: 01/01/2023]
Abstract
The kainic acid model of temporal lobe epilepsy has greatly contributed to the understanding of the molecular, cellular and pharmacological mechanisms underlying epileptogenesis and ictogenesis. This model presents with neuropathological and electroencephalographic features that are seen in patients with temporal lobe epilepsy. It is also characterized by a latent period that follows the initial precipitating injury (i.e., status epilepticus) until the appearance of recurrent seizures, as observed in the human condition. Finally, the kainic acid model can be reproduced in a variety of species using either systemic, intrahippocampal or intra-amygdaloid administrations. In this review, we describe the various methodological procedures and evaluate their differences with respect to the behavioral, electroencephalographic and neuropathological correlates. In addition, we compare the kainic acid model with other animal models of temporal lobe epilepsy such as the pilocarpine and the kindling model. We conclude that the kainic acid model is a reliable tool for understanding temporal lobe epilepsy, provided that the differences existing between methodological procedures are taken into account.
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Affiliation(s)
- Maxime Lévesque
- Montreal Neurological Institute and Departments of Neurology & Neurosurgery, and of Physiology, McGill University, Montréal, QC, Canada H3A 2B4
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Guo Y, Baum LW, Sham PC, Wong V, Ng PW, Lui CHT, Sin NC, Tsoi TH, Tang CS, Kwan JS, Yip BH, Xiao SM, Thomas GN, Lau YL, Yang W, Cherny SS, Kwan P. Two-stage genome-wide association study identifies variants in CAMSAP1L1 as susceptibility loci for epilepsy in Chinese. Hum Mol Genet 2011; 21:1184-9. [DOI: 10.1093/hmg/ddr550] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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10
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Giné E, Morales-Garcia JA, Perez-Castillo A, Santos A. Developmental hypothyroidism increases the expression of kainate receptors in the hippocampus and the sensitivity to kainic acid-induced seizures in the rat. Endocrinology 2010; 151:3267-76. [PMID: 20410204 DOI: 10.1210/en.2010-0070] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thyroid hormones are essential for normal brain development, and multiple alterations at behavioral, cognitive, cellular, and molecular levels have been described in animals made hypothyroid during development. Here we analyzed the effect of developmental hypothyroidism in the rat on the sensitivity to kainic acid-induced limbic seizures and the expression of kainate receptors in the hippocampus. Our results show that hypothyroid rats are extremely sensitive to the proconvulsant and neurotoxic effects of kainic acid (KA). Hypothyroid rats entered in status epilepticus at a dose of KA three times lower than that required to reach status epilepticus in control animals. In accordance with this, high levels of glial activation and neuronal loss after low KA dose injections were observed only in the hippocampus of hypothyroid rats. These effects correlated with an increased expression of kainate receptor subunits, excluding GluR5, in the hippocampus of hypothyroid animals. The concentrations of GluR6, GluR7, KAR1, and KAR2 (ionotropic glutamate receptor subunits of the kainic acid subtype) mRNAs were increased between 50 and 250% in hypothyroid animals relative to the values in controls. In agreement with these results, Western blot and immunohistochemical analysis showed a clear increase in the hippocampal content of GluR6/7 proteins in hypothyroid animals.
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Affiliation(s)
- Elena Giné
- Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad Complutense, 28040 Madrid, Spain
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12
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Li T, Yu HM, Sun YF, Song YJ, Zhang GY, Pei DS. Inhibition of cerebral ischemia/reperfusion-induced injury by adenovirus expressed C-terminal amino acids of GluR6. Brain Res 2009; 1300:169-76. [PMID: 19747468 DOI: 10.1016/j.brainres.2009.09.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 08/26/2009] [Accepted: 09/01/2009] [Indexed: 11/20/2022]
Abstract
GluR6 kainate receptor subunit is largely expressed in hippocampus of brain regions and plays an important role in brain ischemia/reperfusion-mediated neuronal cell death. Our previous researches have shown that cerebral ischemia/reperfusion could facilitate the assembly of GluR6 and postsynaptic density protein 95(PSD95) as well as mixed lineage kinase 3(MLK3) and further induce the activation of c-Jun NH2-terminal kinase 3(JNK3), leading to neuronal death of hippocampal CA1. Here, we show that over-expression of C-terminal amino acids of GluR6 can interrupt the combination of GluR6 with PSD95, inhibit the assembly of GluR6.PSD-95.MLK3 signaling module, suppress the activation of JNK3 and the downstream signaling pathway. Thus, our results imply that over-expression of C-terminal amino acids of GluR6 induce neuroprotection against ischaemic brain injury in rat hippocampal CA1 region via suppressing proapoptosis signaling pathways, which can be an experimental foundation for gene therapy of stroke.
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Affiliation(s)
- Ting Li
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, Xuzhou 221002, China
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13
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Rangel A, Madroñal N, Massó AGI, Gavín R, Llorens F, Sumoy L, Torres JM, Delgado-García JM, Río JAD. Regulation of GABA(A) and glutamate receptor expression, synaptic facilitation and long-term potentiation in the hippocampus of prion mutant mice. PLoS One 2009; 4:e7592. [PMID: 19855845 PMCID: PMC2763346 DOI: 10.1371/journal.pone.0007592] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2009] [Accepted: 09/30/2009] [Indexed: 11/18/2022] Open
Abstract
Background Prionopathies are characterized by spongiform brain degeneration, myoclonia, dementia, and periodic electroencephalographic (EEG) disturbances. The hallmark of prioniopathies is the presence of an abnormal conformational isoform (PrPsc) of the natural cellular prion protein (PrPc) encoded by the Prnp gene. Although several roles have been attributed to PrPc, its putative functions in neuronal excitability are unknown. Although early studies of the behavior of Prnp knockout mice described minor changes, later studies report altered behavior. To date, most functional PrPc studies on synaptic plasticity have been performed in vitro. To our knowledge, only one electrophysiological study has been performed in vivo in anesthetized mice, by Curtis and coworkers. They reported no significant differences in paired-pulse facilitation or LTP in the CA1 region after Schaffer collateral/commissural pathway stimulation. Methodology/Principal Findings Here we explore the role of PrPc expression in neurotransmission and neural excitability using wild-type, Prnp −/− and PrPc-overexpressing mice (Tg20 strain). By correlating histopathology with electrophysiology in living behaving mice, we demonstrate that both Prnp −/− mice but, more relevantly Tg20 mice show increased susceptibility to KA, leading to significant cell death in the hippocampus. This finding correlates with enhanced synaptic facilitation in paired-pulse experiments and hippocampal LTP in living behaving mutant mice. Gene expression profiling using Illumina™ microarrays and Ingenuity pathways analysis showed that 129 genes involved in canonical pathways such as Ubiquitination or Neurotransmission were co-regulated in Prnp −/− and Tg20 mice. Lastly, RT-qPCR of neurotransmission-related genes indicated that subunits of GABAA and AMPA-kainate receptors are co-regulated in both Prnp −/− and Tg20 mice. Conclusions/Significance Present results demonstrate that PrPc is necessary for the proper homeostatic functioning of hippocampal circuits, because of its relationships with GABAA and AMPA-Kainate neurotransmission. New PrPc functions have recently been described, which point to PrPc as a target for putative therapies in Alzheimer's disease. However, our results indicate that a “gain of function” strategy in Alzheimer's disease, or a “loss of function” in prionopathies, may impair PrPc function, with devastating effects. In conclusion, we believe that present data should be taken into account in the development of future therapies.
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Affiliation(s)
- Alejandra Rangel
- Molecular and Cellular Neurobiotechnology, Institute for Bioengineering of Catalonia, and Department of Cell Biology, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Noelia Madroñal
- Division de Neurociencias. Universidad Pablo de Olavide, Sevilla, Spain
| | | | - Rosalina Gavín
- Molecular and Cellular Neurobiotechnology, Institute for Bioengineering of Catalonia, and Department of Cell Biology, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Franc Llorens
- Molecular and Cellular Neurobiotechnology, Institute for Bioengineering of Catalonia, and Department of Cell Biology, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Lauro Sumoy
- Institute of Predictive and Personalized Medicine of Cancer, Badalona, Spain
| | - Juan María Torres
- Centro de Investigación en Sanidad Animal (CISA), INIA, Valdeolmos, Madrid, Spain
| | | | - José Antonio Del Río
- Molecular and Cellular Neurobiotechnology, Institute for Bioengineering of Catalonia, and Department of Cell Biology, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
- * E-mail: (JADR); (JMDG)
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Balosso S, Ravizza T, Pierucci M, Calcagno E, Invernizzi R, Di Giovanni G, Esposito E, Vezzani A. Molecular and functional interactions between tumor necrosis factor-alpha receptors and the glutamatergic system in the mouse hippocampus: Implications for seizure susceptibility. Neuroscience 2009; 161:293-300. [DOI: 10.1016/j.neuroscience.2009.03.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 03/03/2009] [Accepted: 03/04/2009] [Indexed: 12/29/2022]
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15
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Vincent P, Mulle C. Kainate receptors in epilepsy and excitotoxicity. Neuroscience 2009; 158:309-23. [DOI: 10.1016/j.neuroscience.2008.02.066] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2007] [Revised: 02/12/2008] [Accepted: 02/21/2008] [Indexed: 10/22/2022]
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Xu X, Sun R, Jin R. The effect of the ketogenic diet on hippocampal GluR5 and Glu(6 mRNA expression and Q/R site editing in the kainate-induced epilepsy model. Epilepsy Behav 2008; 13:445-8. [PMID: 18606572 DOI: 10.1016/j.yebeh.2008.05.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 05/28/2008] [Accepted: 05/29/2008] [Indexed: 11/22/2022]
Abstract
Treatment with the ketogenic diet has been used to control refractory epilepsy for many years, although its anticonvulsant mechanism is unknown. By modulating synaptic transmission in the hippocampus, kainate receptors and their RNA editing might play a role in the antiseizure action of the treatment. To investigate the potential effect of the ketogenic diet on GluR(5) mRNA and GluR(6) mRNA expression and Q/R site editing, we used the kainate-induced epilepsy model in the present study. Reverse transcription polymerase chain reaction was performed to determine GluR(5) and GluR(6) mRNA expression, and RNA editing was analyzed with the BbvIota restriction enzyme assay. The results demonstrated that expression of GluR(6) mRNA, but not GluR(5) mRNA, was significantly increased after 8 weeks of dietary treatment. Neither the GluR(5) nor the GluR(6) RNA editing rate at the Q/R site was significantly changed by dietary treatment. These data indicate that GluR(6) may be involved in the anticonvulsant mechanism of ketogenic diet treatment.
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Affiliation(s)
- Xiangping Xu
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan 250012, China.
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Rangel A, Burgaya F, Gavín R, Soriano E, Aguzzi A, Del Río JA. Enhanced susceptibility of Prnp-deficient mice to kainate-induced seizures, neuronal apoptosis, and death: Role of AMPA/kainate receptors. J Neurosci Res 2008; 85:2741-55. [PMID: 17304577 DOI: 10.1002/jnr.21215] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Normal physiologic functions of the cellular prion protein (PrPc) are still elusive. This GPI-anchored protein exerts many functions, including roles in neuron proliferation, neuroprotection or redox homeostasis. There are, however, conflicting data concerning its role in synaptic transmission. Although several studies report that PrPc participates in NMDA-mediated neurotransmission, parallel studies describe normal behavior of PrPc-mutant mice. Abnormal axon connections have been described in the dentate gyrus of the hippocampi of PrPc-deficient mice similar to those observed in epilepsy. A study indicates increased susceptibility to kainate (KA) in these mutant mice. We extend the observation of these studies by means of several histologic and biochemical analyses of KA-treated mice. PrPc-deficient mice showed increased sensitivity to KA-induced seizures in vivo and in vitro in organotypic slices. In addition, we show that this sensitivity is cell-specific because interference experiments to abolish PrPc expression increased susceptibility to KA in PrPc-expressing cells. We indicate a correlation of susceptibility to KA in cells lacking PrPc with the differential expression of GluR6 and GluR7 KA receptor subunits using real-time RT-PCR methods. These results indicate that PrPc exerts a neuroprotective role against KA-induced neurotoxicity, probably by regulating the expression of KA receptor subunits.
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Affiliation(s)
- Alejandra Rangel
- Cellular and Molecular Basis of Neurodegeneration and Neurorepair, Department of Cell Biology, University of Barcelona, Spain
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West PJ, Dalpé-Charron A, Wilcox KS. Differential contribution of kainate receptors to excitatory postsynaptic currents in superficial layer neurons of the rat medial entorhinal cortex. Neuroscience 2007; 146:1000-12. [PMID: 17395391 PMCID: PMC2921318 DOI: 10.1016/j.neuroscience.2007.02.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Revised: 02/02/2007] [Accepted: 02/19/2007] [Indexed: 02/02/2023]
Abstract
Although in situ hybridization studies have revealed the presence of kainate receptor (KAR) mRNA in neurons of the rat medial entorhinal cortex (mEC), the functional presence and roles of these receptors are only beginning to be examined. To address this deficiency, whole cell voltage clamp recordings of locally evoked excitatory postsynaptic currents (EPSCs) were made from mEC layer II and III neurons in combined entorhinal cortex-hippocampal brain slices. Three types of neurons were identified by their electroresponsive membrane properties, locations, and morphologies: stellate-like "Sag" neurons in layer II (S), pyramidal-like "No Sag" neurons in layer III (NS), and "Intermediate Sag" neurons with varied morphologies and locations (IS). Non-NMDA EPSCs in these neurons were composed of two components, and the slow decay component in NS neurons had larger amplitudes and contributed more to the combined EPSC than did those observed in S and IS neurons. This slow component was mediated by KARs and was characterized by its resistance to either 1-(4-aminophenyl)-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine hydrochloride (GYKI 52466, 100 microM) or 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[lsqb]f[rsqb]quinoxaline-7-sulfonamide (NBQX, 1 microM), relatively slow decay kinetics, and sensitivity to 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 10-50 microM). KAR-mediated EPSCs in pyramidal-like NS neurons contributed significantly more to the combined non-NMDA EPSC than did those from S and IS neurons. Layer III neurons of the mEC are selectively susceptible to degeneration in human temporal lobe epilepsy (TLE) and animal models of TLE such as kainate-induced status epilepticus. Characterizing differences in the complement of postsynaptic receptors expressed in injury prone versus injury resistant mEC neurons represents an important step toward understanding the vulnerability of layer III neurons seen in TLE.
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Affiliation(s)
- P J West
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
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19
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Beas-Zárate C, Ureña-Guerrero ME, Flores-Soto M, Armendariz-Borunda J, Ortuño-Sahagún D. The expression and binding of kainate receptors is modified in different brain regions by glutamate neurotoxicity during postnatal rat development. Int J Dev Neurosci 2006; 25:53-61. [PMID: 17141463 DOI: 10.1016/j.ijdevneu.2006.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 10/20/2006] [Accepted: 10/23/2006] [Indexed: 10/23/2022] Open
Abstract
Kainic acid receptor (KA-R) subunits are differentially expressed during brain development, and they modulate both neural growth and survival. High concentrations of glutamate in the brain can induce neuronal injury through these receptors, altering normal development. However, it is unclear whether KAR subunit expression itself is also modified by neonatal exposure to high glutamate. To analyze this, monosodium glutamate (4mg/g of body weight) was subcutaneously administered on postnatal days 1, 3, 5 and 7, and the expression of GluR5, GluR6, KA1 and KA2, as well as [(3)H]-kainic acid (KA-R) binding, was evaluated on postnatal days 14, 21, 30 and 60 in different regions of rat brain. As a result, high levels of GluR5 expression associated with strong [(3)H]-kainic acid binding were observed on postnatal days 30 and 60 in the cerebral cortex of rats exposed to glutamate. Similarly, the changes induced by glutamate administration in the expression of the KA1 and KA2 subunits were paralleled by those of [(3)H]-kainic acid binding in the striatum at postnatal days 21 and 30. In contrast, while KAR subunits were over expressed in the hippocampus, no changes were observed in [(3)H]-kainic acid binding in adult rats that had been exposed to glutamate. Therefore, glutamate modifies both the expression of kainic acid receptor subunits and kainic acid binding in a determined spatial and temporal manner, which may be indicative of a regional susceptibility to glutamate neurotoxicity.
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Affiliation(s)
- C Beas-Zárate
- Laboratorio de Neurobiología Celular y Molecular, División de Neurociencias, CIBO, IMSS, Mexico.
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20
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Porter BE, Cui XN, Brooks-Kayal AR. Status epilepticus differentially alters AMPA and kainate receptor subunit expression in mature and immature dentate granule neurons. Eur J Neurosci 2006; 23:2857-63. [PMID: 16819974 DOI: 10.1111/j.1460-9568.2006.04839.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There is an increase in the birth of dentate granule neurons after status epilepticus (SE) and there are concurrent alterations in neurotransmitter receptor expression that may contribute to the development of spontaneous seizures. To determine whether newborn and/or mature dentate granule neurons have altered neurotransmitter receptor expression after SE, we dissected individual immature, PSA-NCAM-expressing, or mature, NeuN-expressing, dentate granule neurons 2 weeks after lithium-pilocarpine-induced SE in postnatal day 20 rats. Amplified single-cell RNA was used to probe reverse Northern blots containing alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainate neurotransmitter receptor subunits. Two weeks after lithium-pilocarpine-induced SE there were increases in AMPA GluR2 and kainate KA2 subunit mRNA and decreases in AMPA GluR3 and kainate GluR6 receptor subunit mRNA levels in mature dentate granule neurons. In contrast, only the kainate GluR6 subunit expression was reduced in immature dentate granule neurons after SE. Alterations in transcription of excitatory amino acid receptor subunits after SE occur primarily in the mature population of dentate granule neurons. Our findings suggest that neurotransmitter receptor gene expression is altered differently in immature and mature dentate granule neurons following SE, and may result in differential contributions of these two groups of dentate granule neurons to the subsequent development of epilepsy.
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MESH Headings
- Animals
- Animals, Newborn
- Blotting, Northern/methods
- Blotting, Western/methods
- Dentate Gyrus/growth & development
- Dentate Gyrus/pathology
- Dentate Gyrus/physiopathology
- Disease Models, Animal
- Gene Expression Regulation, Developmental/physiology
- Immunohistochemistry/methods
- Lithium/toxicity
- Neural Cell Adhesion Molecule L1/metabolism
- Neurons/metabolism
- Phosphopyruvate Hydratase/metabolism
- Pilocarpine/toxicity
- Protein Subunits/genetics
- Protein Subunits/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, AMPA/genetics
- Receptors, AMPA/metabolism
- Receptors, Kainic Acid/genetics
- Receptors, Kainic Acid/metabolism
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Sialic Acids/metabolism
- Status Epilepticus/chemically induced
- Status Epilepticus/pathology
- Status Epilepticus/physiopathology
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21
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Abstract
Kainate receptors form a family of ionotropic glutamate receptors that appear to play a special role in the regulation of the activity of synaptic networks. This review first describes briefly the molecular and pharmacological properties of native and recombinant kainate receptors. It then attempts to outline the general principles that appear to govern the function of kainate receptors in the activity of synaptic networks under physiological conditions. It subsequently describes the way that kainate receptors are involved in synaptic integration, synaptic plasticity, the regulation of neurotransmitter release and the control of neuronal excitability, and the manner in which they might play an important role in synaptogenesis and synaptic maturation. These functions require the proper subcellular localization of kainate receptors in specific functional domains of the neuron, necessitating complex cellular and molecular trafficking events. We show that our comprehension of these mechanisms is just starting to emerge. Finally, this review presents evidence that implicates kainate receptors in pathophysiological conditions such as epilepsy, excitotoxicity and pain, and that shows that these receptors represent promising therapeutic targets.
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Affiliation(s)
- Paulo Pinheiro
- CNRS UMR 5091, Laboratoire "Physiologie Cellulaire de la Synapse", Bordeaux Neuroscience Institute, University of Bordeaux, 33077 Bordeaux Cedex, France
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22
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Hao ZB, Pei DS, Guan QH, Zhang GY. Calcium/calmodulin-dependent protein kinase II (CaMKII), through NMDA receptors and L-Voltage-gated channels, modulates the serine phosphorylation of GluR6 during cerebral ischemia and early reperfusion period in rat hippocampus. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2005; 140:55-62. [PMID: 16126302 DOI: 10.1016/j.molbrainres.2005.07.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2004] [Revised: 04/01/2005] [Accepted: 07/09/2005] [Indexed: 11/17/2022]
Abstract
Recent studies have shown that GluR6 is involved in the modulation of neuronal cell death. It has been shown that PKA can phosphorylate recombinant GluR6 homomeric receptors and that this phosphorylation of GluR6 was suggested to underlie an enhancement of whole-cell current responses. Here, we try to find out whether brain ischemia and reperfusion could induce any change in the serine phosphorylation of GluR6. Our results showed that the serine phosphorylation of GluR6 increased in hippocampus during brain ischemia and early reperfusion period. Then, we used several drugs to investigate the mechanism of modulating the serine phosphorylation of GluR6. KT5720, a specific cell-permeable inhibitor of protein kinase A (PKA), had no effect on the increase in serine phosphorylation of GluR6 induced by brain ischemia or reperfusion. On the other hand, KN-62, a selective inhibitor of rat brain Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), diminished the increase in serine phosphorylation of GluR6. Moreover, our results showed that either MK801 (a NMDA receptor antagonist) or Nifedipine (a L-type Ca2+ channel (L-VGCC) blocker) decreased the increase in serine phosphorylation. In conclusion, our results suggest that CaMKII, activated through NMDA receptors and L-VGCCs, mediated the serine phosphorylation of GluR6 during brain ischemia and early reperfusion period.
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Affiliation(s)
- Zhi-Bin Hao
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou, Jiangsu 221002, PR China
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23
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Ullal G, Fahnestock M, Racine R. Time-dependent effect of kainate-induced seizures on glutamate receptor GluR5, GluR6, and GluR7 mRNA and Protein Expression in rat hippocampus. Epilepsia 2005; 46:616-23. [PMID: 15857425 DOI: 10.1111/j.1528-1167.2005.49604.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE Glutamate receptor 6 is strongly implicated in human refractory epilepsy and in kainic acid (KA)-induced status epilepticus (SE). In vitro pharmacologic studies with newer antiepileptic drugs (AEDs) are increasingly indicating the role of glutamate receptor 5 (GluR5) in epilepsy. Glutamate receptor 7 (GluR7) has been the least investigated in the context of epilepsy. We studied the messenger ribonucleic acid (mRNA) and protein expression of GluR5, GluR6, and GluR7 in rat hippocampus 72 h, 90 days, and 180 days after KA-induced SE. METHODS SE was induced by injecting KA intraperitoneally (i.p.) into adult rats. The hippocampi were isolated 72 h, 90 days, and 180 days after SE. Reverse transcription-polymerase chain reaction (RT-PCR) was performed for mRNA expression. Western blots determined the protein expression. RESULTS A significant increase was noted in GluR5 expression in KA-treated animals compared with controls at 72 h and 180 days, with no significant difference at the intervening 90-day point. Protein levels for GluR5 increased at 72 h and remained elevated until 180 days. GluR7 mRNA showed a significant decrease at 90 days after seizures. Neither the mRNA expression nor the protein levels of GluR6 differed from controls at any of the times after SE. CONCLUSIONS KA-induced SE leads to an upregulation of GluR5 mRNA and protein and a downregulation of GluR7 mRNA in rat hippocampus, with no change in GluR6 mRNA or protein expression.
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MESH Headings
- Animals
- Blotting, Western
- Down-Regulation/drug effects
- Gene Expression/drug effects
- Hippocampus/drug effects
- Hippocampus/metabolism
- Injections, Intraperitoneal
- Kainic Acid/pharmacokinetics
- Kainic Acid/pharmacology
- Male
- Protein Biosynthesis/drug effects
- Protein Biosynthesis/genetics
- RNA, Messenger/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Long-Evans
- Receptors, Glutamate/drug effects
- Receptors, Glutamate/genetics
- Receptors, Glutamate/metabolism
- Receptors, Kainic Acid/biosynthesis
- Receptors, Kainic Acid/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Status Epilepticus/chemically induced
- Status Epilepticus/genetics
- Status Epilepticus/metabolism
- Up-Regulation/drug effects
- GluK2 Kainate Receptor
- GluK3 Kainate Receptor
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Affiliation(s)
- Gautam Ullal
- Department of Psychology, McMaster University, Hamilton, Ontario, Canada
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24
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Morimoto K, Fahnestock M, Racine RJ. Kindling and status epilepticus models of epilepsy: rewiring the brain. Prog Neurobiol 2004; 73:1-60. [PMID: 15193778 DOI: 10.1016/j.pneurobio.2004.03.009] [Citation(s) in RCA: 611] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2003] [Accepted: 03/24/2004] [Indexed: 01/09/2023]
Abstract
This review focuses on the remodeling of brain circuitry associated with epilepsy, particularly in excitatory glutamate and inhibitory GABA systems, including alterations in synaptic efficacy, growth of new connections, and loss of existing connections. From recent studies on the kindling and status epilepticus models, which have been used most extensively to investigate temporal lobe epilepsy, it is now clear that the brain reorganizes itself in response to excess neural activation, such as seizure activity. The contributing factors to this reorganization include activation of glutamate receptors, second messengers, immediate early genes, transcription factors, neurotrophic factors, axon guidance molecules, protein synthesis, neurogenesis, and synaptogenesis. Some of the resulting changes may, in turn, contribute to the permanent alterations in seizure susceptibility. There is increasing evidence that neurogenesis and synaptogenesis can appear not only in the mossy fiber pathway in the hippocampus but also in other limbic structures. Neuronal loss, induced by prolonged seizure activity, may also contribute to circuit restructuring, particularly in the status epilepticus model. However, it is unlikely that any one structure, plastic system, neurotrophin, or downstream effector pathway is uniquely critical for epileptogenesis. The sensitivity of neural systems to the modulation of inhibition makes a disinhibition hypothesis compelling for both the triggering stage of the epileptic response and the long-term changes that promote the epileptic state. Loss of selective types of interneurons, alteration of GABA receptor configuration, and/or decrease in dendritic inhibition could contribute to the development of spontaneous seizures.
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Affiliation(s)
- Kiyoshi Morimoto
- Department of Neuropsychiatry, Faculty of Medicine, Kagawa University, Kagawa 761-0793, Japan
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25
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Delorme R, Krebs MO, Chabane N, Roy I, Millet B, Mouren-Simeoni MC, Maier W, Bourgeron T, Leboyer M. Frequency and transmission of glutamate receptors GRIK2 and GRIK3 polymorphisms in patients with obsessive compulsive disorder. Neuroreport 2004; 15:699-702. [PMID: 15094479 DOI: 10.1097/00001756-200403220-00025] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Several lines of evidence suggest that obsessive compulsive disorder (OCD) could be the consequence of glutamatergic dysfunction. We performed a case-control study in 156 patients and 141 controls and the transmission disequilibrium test in 124 parent-offspring trios to search for association between OCD and two kainate receptors, GRIK2 and GRIK3. Using three single nucleotide polymorphisms (SNP) in GRIK2 and one in GRIK3, we found no evidence for association in case-control or family-based analyses. Only the GRIK2 SNP I867, recently associated with autism, was less transmitted than expected (p < 0.03), supporting a functional role for this variant. These findings suggest the need for further investigation of the role of GRIK2 in OCD.
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Affiliation(s)
- Richard Delorme
- INSERM U 513, Faculté de Médecine, 8 rue du Général Sarrail, 94010 Créteil, France.
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26
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Doucette TA, Bernard PB, Husum H, Perry MA, Ryan CL, Tasker RA. Low doses of domoic acid during postnatal development produce permanent changes in rat behaviour and hippocampal morphology. Neurotox Res 2004; 6:555-63. [PMID: 15639787 DOI: 10.1007/bf03033451] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
It is well established that the developing brain is a highly dynamic environment that is susceptible to toxicity produced by a number of pharmacological, chemical and environmental insults. We report herein on permanent behavioural and morphological changes produced by exposing newborn rats to very low (subconvulsive) doses of kainate receptor agonists during a critical window of brain development. Daily treatment of SD rat pups with either 5 or 20 microg/kg of domoic acid (DOM) from postnatal day 8-14 resulted in a permanent and reproducible seizure-like syndrome when animals were exposed to different tests of spatial cognition as adults. Similar results were obtained when animals were treated with equi-efficacious doses of kainic acid (KA; 25 or 100 microg/kg). Treated rats had significant increases in hippocampal mossy fiber staining and reductions in hippocampal cell counts consistent with effects seen in adult rats following acute injections of high doses of kainic acid. In situ hybridization also revealed an elevation in hippocampal brain derived neurotrophic factor (BDNF) mRNA in region CA1 without a corresponding increase in neuropeptide Y (NPY) mRNA. These results provide evidence of long-lasting behavioural and histochemical consequences arising from relatively subtle changes in glutamatergic activity during development, that may be relevant to understanding the aetiology of seizure disorders and other forms of neurological disease.
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Affiliation(s)
- T A Doucette
- Department of Biology, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 Canada
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27
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Zhang G, Raol YSH, Hsu FC, Brooks-Kayal AR. Long-term alterations in glutamate receptor and transporter expression following early-life seizures are associated with increased seizure susceptibility. J Neurochem 2003; 88:91-101. [PMID: 14675153 DOI: 10.1046/j.1471-4159.2003.02124.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Prolonged seizures in early childhood are associated with an increased risk of development of epilepsy in later life. The mechanism(s) behind this susceptibility to later development of epilepsy is unclear. Increased synaptic activity during development has been shown to permanently alter excitatory neurotransmission and could be one of the mechanisms involved in this increased susceptibility to the development of epilepsy. In the present study we determine the effect of status-epilepticus induced by lithium/pilocarpine at postnatal day 10 (P10 SE) on the expression of glutamate receptor and transporter mRNAs in hippocampal dentate granule cells and protein levels in dentate gyrus of these animals in adulthood. The results revealed a decrease in glutamate receptor 2 (GluR2) mRNA expression and protein levels as well as an increase in protein levels for the excitatory amino acid carrier 1 (EAAC1) in P10 SE rats compared to controls. Expression of glutamate receptor 1 (GluR1) mRNA was decreased in both P10 SE rats and identically handled, lithium-injected littermate controls compared to naive animals, and GluR1 protein levels were significantly lower in lithium-controls than in naive rats, suggesting an effect of either the handling or the lithium on GluR1 expression. These changes in EAA receptors and transporters were accompanied by an increased susceptibility to kainic acid induced seizures in P10 SE rats compared to controls. The current data suggest that early-life status-epilepticus can result in permanent alterations in glutamate receptor and transporter gene expression, which may contribute to a lower seizure threshold.
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Affiliation(s)
- Guojun Zhang
- Division of Neurology, Pediatric Regional Epilepsy Program, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
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28
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Peña F, Bargas J, Tapia R. Paired pulse facilitation is turned into paired pulse depression in hippocampal slices after epilepsy induced by 4-aminopyridine in vivo. Neuropharmacology 2002; 42:807-12. [PMID: 12015207 DOI: 10.1016/s0028-3908(02)00024-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Modifications in synaptic plasticity seem to play a key role in the origin and persistence of epilepsy. 4-Aminopyridine (4-AP) induces intense and long lasting epileptic seizures and neurodegeneration when applied into the hippocampus in vivo, effects that seem to be mediated by overactivation of glutamate receptors due to the enhancement of glutamate release from nerve endings. We have studied presynaptic modifications of CA1 responses, using the paired pulse paradigm, in hippocampal slices obtained from 4-AP-treated rats killed during epileptic activity (ex vivo). The paired pulse facilitation (PPF) observed in control slices with interstimulus intervals of 10-30 ms was changed into paired pulse depression (PPD) after 100 microM 4-AP added in vitro. A strikingly similar change was observed in the ex vivo slices even though 4-AP was no longer present in the tissue. We conclude that the facilitation of glutamate release induced by 4-AP becomes chronic after a transient exposure to the drug. This suggests that the facilitated neurotransmitter release induced by 4-AP triggers a more permanent plastic change that may be responsible for the persistence of epilepsy.
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Affiliation(s)
- F Peña
- Departamento de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, AP 70-253, 04510 Mexico, DF, Mexico
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29
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Jamain S, Betancur C, Quach H, Philippe A, Fellous M, Giros B, Gillberg C, Leboyer M, Bourgeron T. Linkage and association of the glutamate receptor 6 gene with autism. Mol Psychiatry 2002; 7:302-10. [PMID: 11920157 PMCID: PMC2547854 DOI: 10.1038/sj.mp.4000979] [Citation(s) in RCA: 233] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2001] [Accepted: 08/08/2001] [Indexed: 11/09/2022]
Abstract
A genome scan was previously performed and pointed to chromosome 6q21 as a candidate region for autism. This region contains the glutamate receptor 6 (GluR6 or GRIK2) gene, a functional candidate for the syndrome. Glutamate is the principal excitatory neurotransmitter in the brain and is directly involved in cognitive functions such as memory and learning. We used two different approaches, the affected sib-pair (ASP) method and the transmission disequilibrium test (TDT), to investigate the linkage and association between GluR6 and autism. The ASP method, conducted with additional markers on the 51 original families and in eight new sibling pairs, showed a significant excess of allele sharing, generating an elevated multipoint maximum LOD score (ASPEX MLS = 3.28). TDT analysis, performed in the ASP families and in an independent data set of 107 parent-offspring trios, indicated a significant maternal transmission disequilibrium (TDTall P = 0.0004). Furthermore, TDT analysis (with only one affected proband per family) showed significant association between GluR6 and autism (TDT association P = 0.008). In contrast to maternal transmission, paternal transmission of GluR6 alleles was as expected in the absence of linkage, suggesting a maternal effect such as imprinting. Mutation screening was performed in 33 affected individuals, revealing several nucleotide polymorphisms (SNPs), including one amino acid change (M867I) in a highly conserved domain of the intracytoplasmic C-terminal region of the protein. This change is found in 8% of the autistic subjects and in 4% of the control population and seems to be more maternally transmitted than expected to autistic males (P = 0.007). Taken together, these data suggest that GluR6 is in linkage disequilibrium with autism.
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Affiliation(s)
- Stéphane Jamain
- Génomique fonctionnelle et développement
INSERM : EPI0021Institut Pasteur de ParisUnité d'Immunogénétique humaine,
25 rue du Docteur Roux
75724 Paris Cedex 15,FR
| | - Catalina Betancur
- Neurobiologie et Psychiatrie
INSERM : U513Université Paris XII Val de MarneFaculte de Medecine PARIS XII
8, Rue du General Sarrail
94010 CRETEIL CEDEX,FR
| | - Hélène Quach
- Génomique fonctionnelle et développement
INSERM : EPI0021Institut Pasteur de ParisUnité d'Immunogénétique humaine,
25 rue du Docteur Roux
75724 Paris Cedex 15,FR
| | - Anne Philippe
- Neurobiologie et Psychiatrie
INSERM : U513Université Paris XII Val de MarneFaculte de Medecine PARIS XII
8, Rue du General Sarrail
94010 CRETEIL CEDEX,FR
| | - Marc Fellous
- Génomique fonctionnelle et développement
INSERM : EPI0021Institut Pasteur de ParisUnité d'Immunogénétique humaine,
25 rue du Docteur Roux
75724 Paris Cedex 15,FR
| | - Bruno Giros
- Neurobiologie et Psychiatrie
INSERM : U513Université Paris XII Val de MarneFaculte de Medecine PARIS XII
8, Rue du General Sarrail
94010 CRETEIL CEDEX,FR
| | | | - Marion Leboyer
- Neurobiologie et Psychiatrie
INSERM : U513Université Paris XII Val de MarneFaculte de Medecine PARIS XII
8, Rue du General Sarrail
94010 CRETEIL CEDEX,FR
- Département de Psychiatrie
AP-HPHôpital Albert Chenevier40 rue de Mesly
94000 Créteil,FR
| | - Thomas Bourgeron
- Génomique fonctionnelle et développement
INSERM : EPI0021Institut Pasteur de ParisUnité d'Immunogénétique humaine,
25 rue du Docteur Roux
75724 Paris Cedex 15,FR
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30
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Janson CG, McPhee SW, Leone P, Freese A, During MJ. Viral-based gene transfer to the mammalian CNS for functional genomic studies. Trends Neurosci 2001; 24:706-12. [PMID: 11718875 DOI: 10.1016/s0166-2236(00)01954-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A fundamental problem in neuroscience has been the creation of suitable in vivo model systems to study basic neurological phenomena and pathology of the central nervous system (CNS). Somatic cell genetic engineering with viral vectors provides a versatile tool to model normal brain physiology and a variety of neurological diseases.
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Affiliation(s)
- C G Janson
- CNG Gene Therapy Center, Jefferson Medical College, 1025 Walnut Street, Suite 511, Philadelphia, PA 19107, USA.
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31
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Lowenstein PR, Castro MG. Genetic engineering within the adult brain: implications for molecular approaches to behavioral neuroscience. Physiol Behav 2001; 73:833-9. [PMID: 11566216 DOI: 10.1016/s0031-9384(01)00520-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Currently, the most popular technology used to modify the molecular makeup of the nervous system is through germline modifications of early embryos. This allows to construct gene 'knock-ins' (gene overexpression) or 'knock-outs' (gene deletions). This technology leads to gene additions or deletions from the earliest developmental stages. This can potentially lead to compensatory genetic changes. The technology to achieve inducible and cell-type-specific changes in gene expression in transgenic animals has been established. However, it is not yet possible, to reliably turn a particular gene 'on' or 'off' exclusively in adult animals. Alternatively, the use of gene transfer technology in fully mature animals could overcome many of these shortcomings. Gene therapy is the use of nucleic acids as drugs, and uses gene transfer technology to genetically engineer adult animals. Viral and nonviral vectors have been modified to serve as vectors for nucleic acid sequences of interest. Thus, over the last two decades, methods have been developed to deliver particular nucleic acids directly to target tissues. Further technological advances allow delivery of transgenes or antisense mRNAs directly to predetermined cell types, as well as their delivery under the control of inducible promoter elements. Combined transgenic (i.e., germline modifications) and viral vector technology will also be very powerful in allowing the genetic modification of selected neuronal populations in adult animals. In this review, we discuss the potential of gene delivery to the brain to analyze the effect of genetic engineering of particular neuronal groups on behavior, as well as recent developments and applications of newly engineered vector systems to allow transgenesis within nervous structures of adult animals.
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Affiliation(s)
- P R Lowenstein
- Molecular Medicine and Gene Therapy Unit, School of Medicine, University of Manchester, Room 1.302, Stopford Building, Oxford Road, Manchester M13 9PT, UK.
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Sattler R, Tymianski M. Molecular mechanisms of glutamate receptor-mediated excitotoxic neuronal cell death. Mol Neurobiol 2001; 24:107-29. [PMID: 11831548 DOI: 10.1385/mn:24:1-3:107] [Citation(s) in RCA: 402] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Excitotoxicity is one of the most extensively studied processes of neuronal cell death, and plays an important role in many central nervous system (CNS) diseases, including CNS ischemia, trauma, and neurodegenerative disorders. First described by Olney, excitotoxicity was later characterized as an excessive synaptic release of glutamate, which in turn activates postsynaptic glutamate receptors. While almost every glutamate receptor subtype has been implicated in mediating excitotoxic cell death, it is generally accepted that the N-methyl-D-aspartate (NMDA) subtypes play a major role, mainly owing to their high calcium (Ca2+) permeability. However, other glutamate receptor subtypes such as 2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl) propionate (AMPA) or kainate receptors have also been attributed a critical role in mediating excitotoxic neuronal cell death. Although the molecular basis of glutamate toxicity is uncertain, there is general agreement that it is in large part Ca(2+)-dependent. The present review is aimed at summarizing the molecular mechanisms of NMDA receptor and AMPA/kainate receptor-mediated excitotoxic neuronal cell death.
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Affiliation(s)
- R Sattler
- Johns Hopkins University School of Medicine, Howard Hughes Medical Institute, Department of Neuroscience, Baltimore MD 21209, USA.
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Herdegen T, Waetzig V. AP-1 proteins in the adult brain: facts and fiction about effectors of neuroprotection and neurodegeneration. Oncogene 2001; 20:2424-37. [PMID: 11402338 DOI: 10.1038/sj.onc.1204387] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Jun and Fos proteins are induced and activated following most physiological and pathophysiological stimuli in the brain. Only few data allow conclusions about distinct functions of AP-1 proteins in neurodegeneration and neuroregeneration, and these functions mainly refer to c-Jun and its activation by JNKs. Apoptotic functions of activated c-Jun affect hippocampal, nigral and primary cultured neurons following excitotoxic stimulation and destruction of the neuron-target-axis including withdrawal of trophic molecules. The inhibition of JNKs might exert neuroprotection by subsequent omission of c-Jun activation. Besides endogenous neuronal functions, the c-Jun/AP-1 proteins can damage the nervous system by upregulation of harmful programs in non-neuronal cells (e.g. microglia) with release of neurodegenerative molecules. In contrast, the differentiation with neurite extension and maturation of neural cells in vitro indicate physiological and potentially neuroprotective functions of c-Jun and JNKs including sensoring for alterations in the cytoskeleton. This review summarizes the multiple molecular interfunctions which are involved in the shift from the physiological role to degenerative effects of the Jun/JNK-axis such as cell type-specific expression and intracellular localization of scaffold proteins and upstream activators, antagonistic phosphatases, interaction with other kinase systems, or the activation of transcription factors competing for binding to JNK proteins and AP-1 DNA elements.
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Affiliation(s)
- T Herdegen
- Institute of Pharmacology, Hospitalstrasse 4, 24105 Kiel, Germany
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Savinainen A, Garcia EP, Dorow D, Marshall J, Liu YF. Kainate receptor activation induces mixed lineage kinase-mediated cellular signaling cascades via post-synaptic density protein 95. J Biol Chem 2001; 276:11382-6. [PMID: 11152698 DOI: 10.1074/jbc.m100190200] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Kainate receptor glutamate receptor 6 (GluR6) subunit-deficient and c-Jun N-terminal kinase 3 (JNK3)-null mice share similar phenotypes including resistance to kainite-induced epileptic seizures and neuronal toxicity (Yang, D. D., Kuan, C-Y., Whitmarsh, A. J., Rincon, M., Zheng, T. S., Davis, R. J., Rakis, P., and Flavell, R. (1997) Nature 389, 865-869; Mulle, C., Seiler, A., Perez-Otano, I., Dickinson-Anson, H., Castillo, P. E., Bureau, I., Maron, C., Gage, F. H., Mann, J. R., Bettler, B., and Heinemmann, S. F. (1998) Nature 392, 601-605). This suggests that JNK activation may be involved in GluR6-mediated excitotoxicity. We provide evidence that post-synaptic density protein (PSD-95) links GluR6 to JNK activation by anchoring mixed lineage kinase (MLK) 2 or MLK3, upstream activators of JNKs, to the receptor complex. Association of MLK2 and MLK3 with PSD-95 in HN33 cells and rat brain preparations is dependent upon the SH3 domain of PSD-95, and expression of GluR6 in HN33 cells activated JNKs and induced neuronal apoptosis. Deletion of the PSD-95-binding site of GluR6 reduced both JNK activation and neuronal toxicity. Co-expression of dominant negative MLK2, MLK3, or mitogen-activated kinase kinase (MKK) 4 and MKK7 also significantly attenuated JNK activation and neuronal toxicity mediated by GluR6, and co-expression of PSD-95 with a deficient Src homology 3 domain also inhibited GluR6-induced JNK activation and neuronal toxicity. Our results suggest that PSD-95 plays a critical role in GluR6-mediated JNK activation and excitotoxicity by anchoring MLK to the receptor complex.
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Affiliation(s)
- A Savinainen
- Department of Pharmaceutical Sciences, Northeastern University, Boston, Massachusetts 02115, USA
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