1
|
Differential Levels of Tryptophan-Kynurenine Pathway Metabolites in the Hippocampus, Anterior Temporal Lobe, and Neocortex in an Animal Model of Temporal Lobe Epilepsy. Cells 2022; 11:cells11223560. [PMID: 36428989 PMCID: PMC9688794 DOI: 10.3390/cells11223560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/07/2022] [Accepted: 11/08/2022] [Indexed: 11/12/2022] Open
Abstract
Glutamate-receptor-mediated hyperexcitability contributes to seizure generation in temporal lobe epilepsy (TLE). Tryptophan-kynurenine pathway (TKP) metabolites regulate glutamate receptor activity under physiological conditions. This study was designed to investigate alterations in the levels of TKP metabolites and the differential regulation of glutamatergic activity by TKP metabolites in the hippocampus, anterior temporal lobe (ATL), and neocortex samples of a lithium-pilocarpine rat model of TLE. We observed that levels of tryptophan were reduced in the hippocampus and ATL samples but unaltered in the neocortex samples. The levels of kynurenic acid were reduced in the hippocampus samples and unaltered in the ATL and neocortex samples of the TLE rats. The levels of kynurenine were unaltered in all three regions of the TLE rats. The magnitude of reduction in these metabolites in all regions was unaltered in the TLE rats. The frequency and amplitude of spontaneous excitatory postsynaptic currents were enhanced in hippocampus ATL samples but not in the neocortex samples of the TLE rats. The exogenous application of kynurenic acid inhibited glutamatergic activity in the slice preparations of all these regions in both the control and the TLE rats. However, the magnitude of reduction in the frequency of kynurenic acid was higher in the hippocampus (18.44 ± 2.6% in control vs. 30.02 ± 1.5 in TLE rats) and ATL (16.31 ± 0.91% in control vs. 29.82 ± 3.08% in TLE rats) samples of the TLE rats. These findings suggest the differential regulation of glutamatergic activity by TKP metabolites in the hippocampus, ATL, and neocortex of TLE rats.
Collapse
|
2
|
Marinho AMDN, Lobão-Soares B, Targino HAS, Vasconcellos YJF, Guarnieri R, Carlotti CG. Decreased hippocampal serotonin 5HT 1A expression in mesial temporal lobe of epilepsy patients. Epilepsy Behav 2022; 129:108574. [PMID: 35189481 DOI: 10.1016/j.yebeh.2022.108574] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 01/10/2023]
Abstract
INTRODUCTION Mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) is a surgically remediable epilepsy with a relatively high prevalence and psychiatric comorbidities. Depressive disorders may occur in up to 25% of MTLE-HS patients suggesting a common molecular mechanism underlying both conditions. OBJECTIVE To compare the gene expression comprising serotonin 5HT1A and 5HT2A, noradrenaline (NA) ADRA1A, and ADRA2A receptors in the hippocampus of MTLE-HS patients with and without major depression. METHODS A cross-sectional study allocated 31 patients in three groups: MTLE-HS without psychiatric diagnosis (MTLE-HS group), MTLE-HS with major depression (MTLE-HS-D group) and a control group consisting of healthy volunteers without any neurological or psychiatric disorders. Demographic and clinical characteristics were compared among groups. Gene expression of receptors were analyzed using general linear mixed models (GLMM), with an unstructured matrix, normal link. RESULTS The three groups showed a similar distribution regarding age, gender (p > 0.16), history of initial precipitating injury, family history of epilepsy, monthly frequency of seizures, side of hippocampal sclerosis, interictal spike distribution and anti-seizure medications did not differ between MTLE-HS and MTLE-HS-D groups (p > 0.05). We observed a greater expression of the 5HT1A receptor in the control group when compared to the MTLE-HS (P = .004) and MTLE-HS-D (P = .007). Nevertheless, we did not observe any difference when MTLE-HS and MTLE-HS-D groups were compared to the controls for the ADRA1A (P = .931; P = .931), ADRA2A (P = .120; P = .121) and 5HT2A (P = .638; P = .318, respectively) gene expression. CONCLUSION Mesial temporal lobe epilepsy related to hippocampal sclerosis and MTLE-HS-D patients showed a lowered expression of the 5HT1A receptors when compared with the controls adjusted for age and schooling. Data suggest that temporal lobe epilepsy plasticity may affect serotonin receptors, which may lead to more frequent cases of major depression in this population. More studies comprising wider samples are necessary to confirm these results; they also should investigate serotonin reuptake drugs as an adjuvant therapeutic option for MTLE-HS disorder.
Collapse
Affiliation(s)
| | - Bruno Lobão-Soares
- Department of Biophysics and Pharmacology, Federal University of Rio Grande do Norte (DBF - UFRN), Brazil.
| | | | | | | | - Carlos Gilberto Carlotti
- Department of Surgery, Faculty of Medicine of Ribeirão Preto, Universidade de São Paulo, (FMRP-USP), Brazil
| |
Collapse
|
3
|
Wang GH, Chuang AY, Lai YC, Chen HI, Hsueh SW, Yang YC. Pre- and post-synaptic A-type K + channels regulate glutamatergic transmission and switch of the network into epileptiform oscillations. Br J Pharmacol 2022; 179:3754-3777. [PMID: 35170022 DOI: 10.1111/bph.15818] [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: 08/16/2021] [Revised: 12/28/2021] [Accepted: 02/02/2022] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Anticonvulsants targeting K+ channels have not been clinically available, although neuronal hyperexcitability in seizures could be suppressed by activation of K+ channels. Voltage-gated A-type K+ channel (A-channel) inhibitors may be prescribed for diseases of neuromuscular junction but could cause seizures. Consistently, genetic loss of function of A-channels may also cause seizures. It is unclear why inhibition of A-channels, if compared with the other types of K+ channels, is particularly prone to seizure induction. This hinders the development of relevant therapeutic interventions. EXPERIMENTAL APPROACH The epileptogenic mechanisms of A-channel inhibition and antiepileptic actions of A-channel activation were investigated in electrophysiological and behavioral seizures with pharmacological and optogenetic maneuvers. KEY RESULTS Presynaptic Kv1.4 and postsynaptic Kv4.3 A-channels act synergistically to gate glutamatergic transmission and control rhythmogenesis in the amygdala. The interconnected neurons set into the oscillatory mode by A-channel inhibition would reverberate with regular paces and the same top frequency, demonstrating a spatiotemporally well-orchestrated system with built-in oscillatory rhythms normally curbed by A-channels. Accordingly, selective over-excitation of glutamatergic neurons or inhibition of A-channels suffices to induce behavioral seizures, which are effectively ameliorated by A-channel activators such as NS-5806 or AMPA receptor antagonists such as perampanel. CONCLUSION AND IMPLICATIONS Transsynaptic voltage-dependent A-channels serve as a biophysical-biochemical transducer responsible for a novel form of synaptic plasticity. Such a network-level switch into and out of the oscillatory mode may underlie a wide-scope of telencephalic information processing, or to its extreme, epileptic seizures. A-channels thus constitute a potential target of antiepileptic therapy.
Collapse
Affiliation(s)
- Guan-Hsun Wang
- Department of Neurology, Chang Gung Memorial Hospital, Linkou Medical Center, Tao-Yuan, Taiwan
| | - Ai-Yu Chuang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - Yi-Chen Lai
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - Hsin-I Chen
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - Shu-Wei Hsueh
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - Ya-Chin Yang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan.,Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou Medical Center, Tao-Yuan, Taiwan.,Department of Psychiatry, Chang Gung Memorial Hospital, Linkou Medical Center, Tao-Yuan, Taiwan
| |
Collapse
|
4
|
Dubey V, Dey S, Dixit AB, Tripathi M, Chandra PS, Banerjee J. Differential glutamate receptor expression and function in the hippocampus, anterior temporal lobe and neocortex in a pilocarpine model of temporal lobe epilepsy. Exp Neurol 2021; 347:113916. [PMID: 34752784 DOI: 10.1016/j.expneurol.2021.113916] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 10/04/2021] [Accepted: 11/01/2021] [Indexed: 12/14/2022]
Abstract
Temporal lobe epilepsy (TLE) is the most common form of intractable epilepsy where hyperactive glutamate receptors may contribute to the complex epileptogenic network hubs distributed among different regions. This study was designed to investigate the region-specific molecular alterations of the glutamate receptors and associated excitatory synaptic transmission in pilocarpine rat model of TLE. We recorded spontaneous excitatory postsynaptic currents (EPSCs) from pyramidal neurons in resected rat brain slices of the hippocampus, anterior temporal lobe (ATL) and neocortex. We also performed mRNA and protein expression of the glutamate receptor subunits (NR1, NR2A, NR2B, and GLUR1-4) by qPCR and immunohistochemistry. We observed significant increase in the frequency and amplitude of spontaneous EPSCs in the hippocampal and ATL samples of TLE rats than in control rats. Additionally, the magnitude of the frequency and amplitude was increased in ATL samples compared to that of the hippocampal samples of TLE rats. The mRNA level of NR1 was upregulated in both the hippocampal as well as ATL samples and that of NR2A, NR2B were upregulated only in the hippocampal samples of TLE rats than in control rats. The mRNA level of GLUR4 was upregulated in both the hippocampal as well as ATL samples of TLE rats than in control rats. Immunohistochemical analysis demonstrated that the number of NR1, NR2A, NR2B, and GLUR4 immuno-positive cells were significantly higher in the hippocampal samples whereas number of NR1 and GLUR4 immuno-positive cells were significantly higher in the ATL samples of the TLE rats than in control rats. This study demonstrated the region-specific alterations of glutamate receptor subunits in pilocarpine model of TLE, suggesting possible cellular mechanisms contributing to generation of independent epileptogenic networks in different temporal lobe structures.
Collapse
Affiliation(s)
- Vivek Dubey
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| | - Soumil Dey
- Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India
| | | | - Manjari Tripathi
- Department of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | - P Sarat Chandra
- Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India
| | - Jyotirmoy Banerjee
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India.
| |
Collapse
|
5
|
Dey S, Banerjee Dixit A, Tripathi M, Doddamani RS, Sharma MC, Lalwani S, Chandra PS, Banerjee J. Altered hippocampal kynurenine pathway metabolism contributes to hyperexcitability in human mesial temporal lobe epilepsy-hippocampal sclerosis. Br J Pharmacol 2021; 178:3959-3976. [PMID: 33990935 DOI: 10.1111/bph.15534] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 04/29/2021] [Accepted: 05/03/2021] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Glutamate receptor-mediated enhanced excitatory neurotransmission is typically associated with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). Kynurenic acid and quinolinic acid are two important tryptophan-kynurenine pathway metabolites that modulate glutamate receptor activity. This study was designed to test the hypothesis that alteration in metabolism of tryptophan-kynurenine pathway metabolites in the hippocampus of patients with MTLE-HS contributes to abnormal glutamatergic transmission. EXPERIMENTAL APPROACH Levels of tryptophan-kynurenine pathway metabolites were determined using HPLC and LC-MS/MS in hippocampal samples from patients with MTLE-HS, compared with autopsy and non-seizure control samples. mRNA and protein expressions of tryptophan-kynurenine pathway enzymes were determined by qPCR and Western blot. Spontaneous glutamatergic activities were recorded from pyramidal neurons in the presence of kynurenine and kynurenic acid, using whole-cell patch clamp. KEY RESULTS Levels of kynurenic acid were reduced and quinolinic acid levels were raised in hippocampal samples from MTLE-HS patients, whereas kynurenine levels remained unaltered, compared with levels in non-seizure controls. Spontaneous glutamatergic activity in MTLE-HS hippocampal samples was higher than that in non-seizure controls. Treatment with kynurenine inhibited glutamatergic activity in non-seizure control samples but not in MTLE-HS samples. However, exogenously applied kynurenic acid inhibited glutamatergic activity in both non-seizure control and MTLE-HS hippocampal samples. Also, levels of kynurenine aminotransferase II and its cofactor pyridoxal phosphate were reduced in MTLE-HS samples. CONCLUSION AND IMPLICATIONS Our findings indicate that altered metabolism of tryptophan-kynurenine pathway metabolites in hippocampus could contribute to hyperglutamatergic tone in patients with MTLE-HS.
Collapse
Affiliation(s)
- Soumil Dey
- Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India
| | - Aparna Banerjee Dixit
- Dr. B. R. Ambedkar Centre for Biomedical Research, University of Delhi, New Delhi, India
| | - Manjari Tripathi
- Department of Neurology, All India Institute of Medical Sciences, New Delhi, India
| | | | - Mehar Chand Sharma
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, India
| | - Sanjeev Lalwani
- Department of Forensic Medicine and Toxicology, All India Institute of Medical Sciences, New Delhi, India
| | | | - Jyotirmoy Banerjee
- Department of Biophysics, All India Institute of Medical Sciences, New Delhi, India
| |
Collapse
|
6
|
Synaptic Reshaping and Neuronal Outcomes in the Temporal Lobe Epilepsy. Int J Mol Sci 2021; 22:ijms22083860. [PMID: 33917911 PMCID: PMC8068229 DOI: 10.3390/ijms22083860] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/02/2021] [Accepted: 04/04/2021] [Indexed: 12/11/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is one of the most common types of focal epilepsy, characterized by recurrent spontaneous seizures originating in the temporal lobe(s), with mesial TLE (mTLE) as the worst form of TLE, often associated with hippocampal sclerosis. Abnormal epileptiform discharges are the result, among others, of altered cell-to-cell communication in both chemical and electrical transmissions. Current knowledge about the neurobiology of TLE in human patients emerges from pathological studies of biopsy specimens isolated from the epileptogenic zone or, in a few more recent investigations, from living subjects using positron emission tomography (PET). To overcome limitations related to the use of human tissue, animal models are of great help as they allow the selection of homogeneous samples still presenting a more various scenario of the epileptic syndrome, the presence of a comparable control group, and the availability of a greater amount of tissue for in vitro/ex vivo investigations. This review provides an overview of the structural and functional alterations of synaptic connections in the brain of TLE/mTLE patients and animal models.
Collapse
|
7
|
Pires G, Leitner D, Drummond E, Kanshin E, Nayak S, Askenazi M, Faustin A, Friedman D, Debure L, Ueberheide B, Wisniewski T, Devinsky O. Proteomic differences in the hippocampus and cortex of epilepsy brain tissue. Brain Commun 2021; 3:fcab021. [PMID: 34159317 DOI: 10.1093/braincomms/fcab021] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 12/22/2022] Open
Abstract
Epilepsy is a common neurological disorder affecting over 70 million people worldwide, with a high rate of pharmaco-resistance, diverse comorbidities including progressive cognitive and behavioural disorders, and increased mortality from direct (e.g. sudden unexpected death in epilepsy, accidents, drowning) or indirect effects of seizures and therapies. Extensive research with animal models and human studies provides limited insights into the mechanisms underlying seizures and epileptogenesis, and these have not translated into significant reductions in pharmaco-resistance, morbidities or mortality. To help define changes in molecular signalling networks associated with seizures in epilepsy with a broad range of aetiologies, we examined the proteome of brain samples from epilepsy and control cases. Label-free quantitative mass spectrometry was performed on the hippocampal cornu ammonis 1-3 region (CA1-3), frontal cortex and dentate gyrus microdissected from epilepsy and control cases (n = 14/group). Epilepsy cases had significant differences in the expression of 777 proteins in the hippocampal CA1 - 3 region, 296 proteins in the frontal cortex and 49 proteins in the dentate gyrus in comparison to control cases. Network analysis showed that proteins involved in protein synthesis, mitochondrial function, G-protein signalling and synaptic plasticity were particularly altered in epilepsy. While protein differences were most pronounced in the hippocampus, similar changes were observed in other brain regions indicating broad proteomic abnormalities in epilepsy. Among the most significantly altered proteins, G-protein subunit beta 1 (GNB1) was one of the most significantly decreased proteins in epilepsy in all regions studied, highlighting the importance of G-protein subunit signalling and G-protein-coupled receptors in epilepsy. Our results provide insights into common molecular mechanisms underlying epilepsy across various aetiologies, which may allow for novel targeted therapeutic strategies.
Collapse
Affiliation(s)
- Geoffrey Pires
- Comprehensive Epilepsy Center, New York University Grossman School of Medicine, New York, NY, USA.,Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA.,Alzheimer's and Prion Diseases Team, Paris Brain Institute, CNRS, UMR 7225, INSERM 1127, Sorbonne University UM75, Paris, France
| | - Dominique Leitner
- Comprehensive Epilepsy Center, New York University Grossman School of Medicine, New York, NY, USA
| | - Eleanor Drummond
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA.,Faculty of Medicine and Health, Brain and Mind Centre and School of Medical Sciences, University of Sydney, Sydney, Australia
| | - Evgeny Kanshin
- Proteomics Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, USA
| | - Shruti Nayak
- Proteomics Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, USA
| | - Manor Askenazi
- Biomedical Hosting LLC, USA.,Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, USA
| | - Arline Faustin
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Daniel Friedman
- Comprehensive Epilepsy Center, New York University Grossman School of Medicine, New York, NY, USA
| | - Ludovic Debure
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA
| | - Beatrix Ueberheide
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA.,Proteomics Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, NY, USA.,Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY, USA
| | - Thomas Wisniewski
- Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, NY, USA.,Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, USA.,Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| | - Orrin Devinsky
- Comprehensive Epilepsy Center, New York University Grossman School of Medicine, New York, NY, USA
| |
Collapse
|
8
|
Guzmán-Jiménez DE, Campos JB, Venegas-Vega CA, Sánchez MA, Velasco AL. Familial mesial temporal lobe epilepsy in Mexico: Inheritance pattern and clinical features. Epilepsy Res 2020; 167:106450. [PMID: 32949980 DOI: 10.1016/j.eplepsyres.2020.106450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 08/11/2020] [Accepted: 08/21/2020] [Indexed: 11/19/2022]
Abstract
PURPOSE The objectives of this study were to determine the inheritance pattern by which familial mesial temporal lobe epilepsy (FMTLE) is segregated in Mexican families, and to identify if there was an association between the clinical characteristics and the inheritance pattern. METHOD We included a total of 25 families with two or more members affected with MTLE during two years and elaborated a family pedigree for each family. The inheritance pattern was classified as autosomal dominant (AD) or autosomal recessive (AR), considering the affected members. We used statistical analysis association and differences between clinical characteristics and inheritance patterns. RESULTS The affected families with the AD pattern were 15.7 fold times more likely to start seizures at 5 years of age or earlier than families with AR pattern, OR = 15.7 (IC 95% = 1.9-128.9). We observed a predominance and greater déjà vu association (64.4% vs 31.3%; p = 0.021), OR = 3.9 (CI 95% = 1.1-13.5) in patients with AD versus AR pattern. Finally, we identified that patients with AD pattern had a likelihood of presenting emotional alterations 5.6 times higher than AR (OR = 5.6, IC = 1.1-27.5). CONCLUSION FMTLE is a heterogeneous syndrome, both phenotypically and genotypically; thus, our findings may be helpful for clinical use to perform an early diagnosis, to provide timely treatment, and to prevent comorbidities associated to this disease. However, in order to identify the possible genetic causes underlying these inheritance patterns, the use of molecular studies is necessary.
Collapse
Affiliation(s)
- Diana Elena Guzmán-Jiménez
- Epilepsy Clinic, General Hospital of México "Dr. Eduardo Liceaga", Dr. Balmis 148, 06720, Doctores, Mexico City, Mexico; Programa de Doctorado en Ciencias Biomédicas, División de Estudios de Posgrado, Universidad Nacional Autónoma de México (UNAM), Universidad 3000, 04510, Mexico City, Mexico.
| | - Jaime Berumen Campos
- Medical School, Universidad Nacional Autónoma de México, Mexico City, Mexico; Experimental Medicine Unit, Universidad Nacional Autónoma de México, in the General Hospital of México "Dr. Eduardo Liceaga", Dr. Balmis 148, 06720, Doctores, Mexico City, Mexico.
| | - Carlos Alberto Venegas-Vega
- Medical School, Universidad Nacional Autónoma de México, Mexico City, Mexico; Genetic Unit, General Hospital of México "Dr. Eduardo Liceaga", Dr. Balmis 148, 06720, Doctores, Mexico City, Mexico.
| | - Mariana Alejandre Sánchez
- Epilepsy Clinic, General Hospital of México "Dr. Eduardo Liceaga", Dr. Balmis 148, 06720, Doctores, Mexico City, Mexico.
| | - Ana Luisa Velasco
- Epilepsy Clinic, General Hospital of México "Dr. Eduardo Liceaga", Dr. Balmis 148, 06720, Doctores, Mexico City, Mexico.
| |
Collapse
|
9
|
Stefanits H, Milenkovic I, Mahr N, Pataraia E, Baumgartner C, Hainfellner JA, Kovacs GG, Kasprian G, Sieghart W, Yilmazer-Hanke D, Czech T. Alterations in GABAA Receptor Subunit Expression in the Amygdala and Entorhinal Cortex in Human Temporal Lobe Epilepsy. J Neuropathol Exp Neurol 2020; 78:1022-1048. [PMID: 31631219 DOI: 10.1093/jnen/nlz085] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 07/06/2019] [Indexed: 12/14/2022] Open
Abstract
The amygdala has long been implicated in the pathophysiology of human temporal lobe epilepsy (TLE). The different nuclei of this complex structure are interconnected and share reciprocal connections with the hippocampus and other brain structures, partly via the entorhinal cortex. Expression of GABAA receptor subunits α1, α2, α3, α5, β2, β2/3, and γ2 was evaluated by immunohistochemistry in amygdala specimens and the entorhinal cortex of 12 TLE patients and 12 autopsy controls. A substantial decrease in the expression of α1, α2, α3, and β2/3 subunits was found in TLE cases, accompanied by an increase of γ2 subunit expression in many nuclei. In the entorhinal cortex, the expression of all GABAA receptor subunits was decreased except for the α1 subunit, which was increased on cellular somata. The overall reduction in α subunit expression may lead to decreased sensitivity to GABA and its ligands and compromise phasic inhibition, whereas upregulation of the γ2 subunit might influence clustering and kinetics of receptors and impair tonic inhibition. The description of these alterations in the human amygdala is important for the understanding of network changes in TLE as well as the development of subunit-specific therapeutic agents for the treatment of this disease.
Collapse
Affiliation(s)
- Harald Stefanits
- Department of Neurosurgery, Institute of Neurology, Department of Neurology, Department of Biomedical Imaging and Image Guided Therapy, Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria; Second Neurological Department, General Hospital Hietzing, Vienna, Austria; and Clinical Neuroanatomy, Neurology Department, Medical Faculty, Ulm University, Ulm, Germany
| | - Ivan Milenkovic
- Department of Neurosurgery, Institute of Neurology, Department of Neurology, Department of Biomedical Imaging and Image Guided Therapy, Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria; Second Neurological Department, General Hospital Hietzing, Vienna, Austria; and Clinical Neuroanatomy, Neurology Department, Medical Faculty, Ulm University, Ulm, Germany
| | - Nina Mahr
- Department of Neurosurgery, Institute of Neurology, Department of Neurology, Department of Biomedical Imaging and Image Guided Therapy, Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria; Second Neurological Department, General Hospital Hietzing, Vienna, Austria; and Clinical Neuroanatomy, Neurology Department, Medical Faculty, Ulm University, Ulm, Germany
| | - Ekaterina Pataraia
- Department of Neurosurgery, Institute of Neurology, Department of Neurology, Department of Biomedical Imaging and Image Guided Therapy, Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria; Second Neurological Department, General Hospital Hietzing, Vienna, Austria; and Clinical Neuroanatomy, Neurology Department, Medical Faculty, Ulm University, Ulm, Germany
| | - Christoph Baumgartner
- Department of Neurosurgery, Institute of Neurology, Department of Neurology, Department of Biomedical Imaging and Image Guided Therapy, Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria; Second Neurological Department, General Hospital Hietzing, Vienna, Austria; and Clinical Neuroanatomy, Neurology Department, Medical Faculty, Ulm University, Ulm, Germany
| | - Johannes A Hainfellner
- Department of Neurosurgery, Institute of Neurology, Department of Neurology, Department of Biomedical Imaging and Image Guided Therapy, Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria; Second Neurological Department, General Hospital Hietzing, Vienna, Austria; and Clinical Neuroanatomy, Neurology Department, Medical Faculty, Ulm University, Ulm, Germany
| | - Gabor G Kovacs
- Department of Neurosurgery, Institute of Neurology, Department of Neurology, Department of Biomedical Imaging and Image Guided Therapy, Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria; Second Neurological Department, General Hospital Hietzing, Vienna, Austria; and Clinical Neuroanatomy, Neurology Department, Medical Faculty, Ulm University, Ulm, Germany
| | - Gregor Kasprian
- Department of Neurosurgery, Institute of Neurology, Department of Neurology, Department of Biomedical Imaging and Image Guided Therapy, Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria; Second Neurological Department, General Hospital Hietzing, Vienna, Austria; and Clinical Neuroanatomy, Neurology Department, Medical Faculty, Ulm University, Ulm, Germany
| | - Werner Sieghart
- Department of Neurosurgery, Institute of Neurology, Department of Neurology, Department of Biomedical Imaging and Image Guided Therapy, Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria; Second Neurological Department, General Hospital Hietzing, Vienna, Austria; and Clinical Neuroanatomy, Neurology Department, Medical Faculty, Ulm University, Ulm, Germany
| | - Deniz Yilmazer-Hanke
- Department of Neurosurgery, Institute of Neurology, Department of Neurology, Department of Biomedical Imaging and Image Guided Therapy, Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria; Second Neurological Department, General Hospital Hietzing, Vienna, Austria; and Clinical Neuroanatomy, Neurology Department, Medical Faculty, Ulm University, Ulm, Germany
| | - Thomas Czech
- Department of Neurosurgery, Institute of Neurology, Department of Neurology, Department of Biomedical Imaging and Image Guided Therapy, Center for Brain Research, Department of Molecular Neurosciences, Medical University of Vienna, Vienna, Austria; Second Neurological Department, General Hospital Hietzing, Vienna, Austria; and Clinical Neuroanatomy, Neurology Department, Medical Faculty, Ulm University, Ulm, Germany
| |
Collapse
|
10
|
Hamamoto O, Tirapelli DPDC, Lizarte Neto FS, Freitas-Lima P, Saggioro FP, Cirino MLDA, Assirati JA, Serafini LN, Velasco TR, Sakamoto AC, Carlotti CG. Modulation of NMDA receptor by miR-219 in the amygdala and hippocampus of patients with mesial temporal lobe epilepsy. J Clin Neurosci 2020; 74:180-186. [PMID: 32111564 DOI: 10.1016/j.jocn.2020.02.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/10/2020] [Indexed: 01/28/2023]
Abstract
Mesial temporal lobe epilepsy with hippocampal sclerosis is the most frequent form of focal epilepsy in adults, and it is often refractory to drug treatment. Regardless of the efforts on developing new antiepileptic drugs for refractory cases, studies suggest a need for better understanding the molecular bases of epilepsy. The microRNAs have been progressively investigated as potential targets for both epilepsy mechanisms elucidation and treatment. Therefore, the goal of this study was to evaluate the differential expression of miR-219, miR-181b, and miR-195, previously described as regulators of the excitatory neurotransmitter receptors NMDA-R1 and AMPA-GluR2 and inhibitory neurotransmitter GABAA (α2, β3, and γ2 subunits) in the amygdala and hippocampus of patients with mesial temporal lobe epilepsy. Based on genes and miRNAs' quantitative Polymerase Chain Reaction (qPCR) from 18 patients with epilepsy, our results showed an inverse relationship between miR-219 and NMDA-NR1 expression in both the amygdala and hippocampus in comparison to their expression in controls. NR1 and GluR2 were upregulated in the amygdala of epileptic patients. Low miR-195 expression was observed in the amygdala of patients with epilepsy. Our findings indicate that miR-219 has a possible regulatory role in excitatory neurotransmission in patients with epilepsy, contributing to the new avenue of miRNA biology in drug-resistant epilepsy, reserving huge potential for future applications and clinical interventions in conjunction with existing therapies.
Collapse
Affiliation(s)
- Osmi Hamamoto
- Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | | | - Fermino Sanches Lizarte Neto
- Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Priscila Freitas-Lima
- Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil; Barao de Maua University Center, Ribeirao Preto, SP, Brazil
| | - Fabiano Pinto Saggioro
- Department of Pathology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Mucio Luiz de Assis Cirino
- Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - João Alberto Assirati
- Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Luciano Neder Serafini
- Department of Pathology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Tonicarlo Rodrigues Velasco
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Américo Ceiki Sakamoto
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Carlos Gilberto Carlotti
- Department of Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| |
Collapse
|
11
|
Jafarian M, Modarres Mousavi SM, Alipour F, Aligholi H, Noorbakhsh F, Ghadipasha M, Gharehdaghi J, Kellinghaus C, Kovac S, Khaleghi Ghadiri M, Meuth SG, Speckmann EJ, Stummer W, Gorji A. Cell injury and receptor expression in the epileptic human amygdala. Neurobiol Dis 2019; 124:416-427. [DOI: 10.1016/j.nbd.2018.12.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/04/2018] [Accepted: 12/22/2018] [Indexed: 02/06/2023] Open
|
12
|
Weir RK, Bauman MD, Jacobs B, Schumann CM. Protracted dendritic growth in the typically developing human amygdala and increased spine density in young ASD brains. J Comp Neurol 2017; 526:262-274. [PMID: 28929566 DOI: 10.1002/cne.24332] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 09/01/2017] [Accepted: 09/04/2017] [Indexed: 12/14/2022]
Abstract
The amygdala is a medial temporal lobe structure implicated in social and emotional regulation. In typical development (TD), the amygdala continues to increase volumetrically throughout childhood and into adulthood, while other brain structures are stable or decreasing in volume. In autism spectrum disorder (ASD), the amygdala undergoes rapid early growth, making it volumetrically larger in children with ASD compared to TD children. Here we explore: (a) if dendritic arborization in the amygdala follows the pattern of protracted growth in TD and early overgrowth in ASD and (b), if spine density in the amygdala in ASD cases differs from TD from youth to adulthood. The amygdala from 32 postmortem human brains (7-46 years of age) were stained using a Golgi-Kopsch impregnation. Ten principal neurons per case were selected in the lateral nucleus and traced using Neurolucida software in their entirety. We found that both ASD and TD individuals show a similar pattern of increasing dendritic length with age well into adulthood. However, spine density is (a) greater in young ASD cases compared to age-matched TD controls (<18 years old) and (b) decreases in the amygdala as people with ASD age into adulthood, a phenomenon not found in TD. Therefore, by adulthood, there is no observable difference in spine density in the amygdala between ASD and TD age-matched adults (≥18 years old). Our findings highlight the unique growth trajectory of the amygdala and suggest that spine density may contribute to aberrant development and function of the amygdala in children with ASD.
Collapse
Affiliation(s)
- R K Weir
- Department of Psychiatry and Behavioral Sciences, University of California at Davis MIND Institute, Sacramento, California
| | - M D Bauman
- Department of Psychiatry and Behavioral Sciences, University of California at Davis MIND Institute, Sacramento, California
| | - B Jacobs
- Laboratory of Quantitative Neuromorphology, Department of Psychology, Colorado College, Colorado Springs, Colorado
| | - C M Schumann
- Department of Psychiatry and Behavioral Sciences, University of California at Davis MIND Institute, Sacramento, California
| |
Collapse
|
13
|
Gambardella A, Labate A, Cifelli P, Ruffolo G, Mumoli L, Aronica E, Palma E. Pharmacological modulation in mesial temporal lobe epilepsy: Current status and future perspectives. Pharmacol Res 2016; 113:421-425. [DOI: 10.1016/j.phrs.2016.09.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 09/13/2016] [Accepted: 09/17/2016] [Indexed: 11/29/2022]
|
14
|
The Functional and Molecular Properties, Physiological Functions, and Pathophysiological Roles of GluN2A in the Central Nervous System. Mol Neurobiol 2016; 54:1008-1021. [DOI: 10.1007/s12035-016-9715-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 01/11/2016] [Indexed: 11/25/2022]
|
15
|
Wong SB, Cheng SJ, Hung WC, Lee WT, Min MY. Rosiglitazone Suppresses In Vitro Seizures in Hippocampal Slice by Inhibiting Presynaptic Glutamate Release in a Model of Temporal Lobe Epilepsy. PLoS One 2015; 10:e0144806. [PMID: 26659605 PMCID: PMC4685987 DOI: 10.1371/journal.pone.0144806] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 11/24/2015] [Indexed: 12/13/2022] Open
Abstract
Peroxisomal proliferator-activated receptor gamma (PPARγ) is a nuclear hormone receptor whose agonist, rosiglitazone has a neuroprotective effect to hippocampal neurons in pilocarpine-induced seizures. Hippocampal slice preparations treated in Mg2+ free medium can induce ictal and interictal-like epileptiform discharges, which is regarded as an in vitro model of N-methyl-D-aspartate (NMDA) receptor-mediated temporal lobe epilepsy (TLE). We applied rosiglitazone in hippocampal slices treated in Mg2+ free medium. The effects of rosiglitazone on hippocampal CA1-Schaffer collateral synaptic transmission were tested. We also examined the neuroprotective effect of rosiglitazone toward NMDA excitotoxicity on cultured hippocampal slices. Application of 10μM rosiglitazone significantly suppressed amplitude and frequency of epileptiform discharges in CA1 neurons. Pretreatment with the PPARγ antagonist GW9662 did not block the effect of rosiglitazone on suppressing discharge frequency, but reverse the effect on suppressing discharge amplitude. Application of rosiglitazone suppressed synaptic transmission in the CA1-Schaffer collateral pathway. By miniature excitatory-potential synaptic current (mEPSC) analysis, rosiglitazone significantly suppressed presynaptic neurotransmitter release. This phenomenon can be reversed by pretreating PPARγ antagonist GW9662. Also, rosiglitazone protected cultured hippocampal slices from NMDA-induced excitotoxicity. The protective effect of 10μM rosiglitazone was partially antagonized by concomitant high dose GW9662 treatment, indicating that this effect is partially mediated by PPARγ receptors. In conclusion, rosiglitazone suppressed NMDA receptor-mediated epileptiform discharges by inhibition of presynaptic neurotransmitter release. Rosiglitazone protected hippocampal slice from NMDA excitotoxicity partially by PPARγ activation. We suggest that rosiglitazone could be a potential agent to treat patients with TLE.
Collapse
MESH Headings
- Action Potentials/drug effects
- Anilides/pharmacology
- Animals
- CA1 Region, Hippocampal/drug effects
- CA1 Region, Hippocampal/metabolism
- CA1 Region, Hippocampal/pathology
- Culture Media/chemistry
- Culture Media/pharmacology
- Epilepsy, Temporal Lobe/drug therapy
- Epilepsy, Temporal Lobe/genetics
- Epilepsy, Temporal Lobe/metabolism
- Epilepsy, Temporal Lobe/pathology
- Excitatory Postsynaptic Potentials/drug effects
- Gene Expression Regulation
- Glutamic Acid/metabolism
- Magnesium/pharmacology
- Microtomy
- Models, Biological
- Neurons/drug effects
- Neurons/metabolism
- Neurons/pathology
- Neuroprotective Agents/antagonists & inhibitors
- Neuroprotective Agents/pharmacology
- PPAR gamma/antagonists & inhibitors
- PPAR gamma/genetics
- PPAR gamma/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, N-Methyl-D-Aspartate/agonists
- Receptors, N-Methyl-D-Aspartate/genetics
- Receptors, N-Methyl-D-Aspartate/metabolism
- Rosiglitazone
- Seizures/drug therapy
- Seizures/genetics
- Seizures/metabolism
- Seizures/pathology
- Synaptic Transmission/drug effects
- Thiazolidinediones/antagonists & inhibitors
- Thiazolidinediones/pharmacology
- Tissue Culture Techniques
Collapse
Affiliation(s)
- Shi-Bing Wong
- Department of Pediatrics, Taipei Tzu Chi General Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan
- Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Sin-Jhong Cheng
- Neuroscience Program in Academia Sinica, Taipei, Taiwan
- Institute of Biomedical Sciences; Academia Sinica, Taipei, Taiwan
| | - Wei-Chen Hung
- Department of Pediatrics, Taipei Tzu Chi General Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan
| | - Wang-Tso Lee
- Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan
- * E-mail: (WTL); (MYM)
| | - Ming-Yuan Min
- Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan
- * E-mail: (WTL); (MYM)
| |
Collapse
|
16
|
Yilmazer-Hanke D, O'Loughlin E, McDermott K. Contribution of amygdala pathology to comorbid emotional disturbances in temporal lobe epilepsy. J Neurosci Res 2015; 94:486-503. [DOI: 10.1002/jnr.23689] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 10/07/2015] [Accepted: 10/16/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Deniz Yilmazer-Hanke
- Department of Biomedical Sciences, School of Medicine; Creighton University; Omaha Nebraska
- Department of Anatomy and Neuroscience; University College; Cork Ireland
| | - Elaine O'Loughlin
- Department of Anatomy and Neuroscience; University College; Cork Ireland
- Ann Romney Centre for Neurologic Diseases, Brigham and Women's Hospital; Harvard Medical School; Boston Massachusetts
| | - Kieran McDermott
- Department of Anatomy and Neuroscience; University College; Cork Ireland
- Graduate Entry Medical School; University of Limerick; Limerick Ireland
| |
Collapse
|
17
|
Dixit AB, Tripathi M, Chandra PS, Banerjee J. Molecular biomarkers in drug-resistant epilepsy: Facts & possibilities. Int J Surg 2015; 36:483-491. [PMID: 26306771 DOI: 10.1016/j.ijsu.2015.08.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 08/03/2015] [Indexed: 01/08/2023]
Abstract
Despite great advances in our understanding of the process of epileptogenesis we are yet to develop reliable biomarkers that have the potential to accurately localize the epileptogenic zone (EZ), and to resolve the issue of heterogeneity in epilepsy surgery outcome. Inability to precisely localize the epileptogenic foci is one of the reason why more than 30% of these DRE patients are not benefited. Molecular and cellular biomarkers in combination with imaging and electrical investigations will provide a more specific platform for defining epileptogenic zone. Potential molecular biomarkers of epileptogenesis including markers of inflammation, synaptic alterations and neurodegeneration may also have the potential for localizing EZ. At molecular level components derived from epileptogenic tissues, such as metabolites, proteins, mRNAs and miRNAs that are significantly altered can serve as biomarkers and can be clubbed with existing techniques to preoperatively localize the EZ. Neurosurgeons across the world face problems while defining the margins of the epileptogenic tissues to be resected during surgery. In this review we discuss molecular biomarkers reported so far in the context of epileptogenesis and some of the unexplored markers which may have the potential to localize EZ during surgery. We also discuss "Intelligent knife" technique that couples electrosurgery and mass spectrometry allowing near-real-time characterization of human tissue and may prove to be instrumental in defining the margins of the epileptogenic zone during surgery.
Collapse
Affiliation(s)
- Aparna Banerjee Dixit
- Center of Excellence for Epilepsy, National Brain Research Centre, Manesar, 122051, India
| | - Manjari Tripathi
- Dept. of Neurology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - P Sarat Chandra
- Dept. of Neurosurgery, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Jyotirmoy Banerjee
- Center of Excellence for Epilepsy, National Brain Research Centre, Manesar, 122051, India.
| |
Collapse
|
18
|
Banerjee J, Banerjee Dixit A, Tripathi M, Sarkar C, Gupta YK, Chandra PS. Enhanced endogenous activation of NMDA receptors in pyramidal neurons of hippocampal tissues from patients with mesial temporal lobe epilepsy: A mechanism of hyper excitation. Epilepsy Res 2015; 117:11-6. [PMID: 26320079 DOI: 10.1016/j.eplepsyres.2015.08.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 07/17/2015] [Accepted: 08/08/2015] [Indexed: 11/30/2022]
Abstract
Altered excitatory synaptic transmission is one of the primary causes of seizure generation in patients with mesial temporal lobe epilepsy (MTLE). The present study is designed to delineate the contribution of glutamatergic tone under resting conditions to the hyper excitability in patients with MTLE. Resected hippocampal tissues were obtained from patients with MTLE. In these samples spontaneous excitatory postsynaptic currents (EPSCs), sensitive to NMDA receptor antagonist APV (50μM) and AMPA receptor antagonist CNQX (10μM) were recorded from pyramidal neurons at -70mV. We observed that frequency of EPSCs were 28.2% higher in slices obtained from patients with MTLE compared to that in case of non-epileptic controls. We also examined spontaneous fast current transients (CTs) recorded from these pyramidal neurons under cell-attached configuration. The frequency of CTs increased in the absence of extracellular Mg(2+) in brain slice preparations and was completely blocked by APV. We found that the frequency of CTs in pyramidal neurons were higher in case of MTLE samples compared to non-epileptic controls. This study suggests that enhanced endogenous activity of NMDA receptor contributes to excitability in pyramidal neurons of slice preparations obtained from patients with MTLE.
Collapse
Affiliation(s)
- Jyotirmoy Banerjee
- Center of Excellence for Epilepsy, National Brain Research Center, Manesar, India.
| | | | - Manjari Tripathi
- Center of Excellence for Epilepsy, National Brain Research Center, Manesar, India; Department of Neurology, All India Institute of Medical Sciences, New Delhi, India.
| | - Chitra Sarkar
- Department of Neuropathology, All India Institute of Medical Sciences, New Delhi, India.
| | - Yogendra Kumar Gupta
- Department of Pharmacology, All India Institute of Medical Sciences, New Delhi, India.
| | - P Sarat Chandra
- Center of Excellence for Epilepsy, National Brain Research Center, Manesar, India; Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India.
| |
Collapse
|
19
|
Wen M, Yan Y, Yan N, Chen XS, Liu SY, Feng ZH. Upregulation of RBFOX1 in the malformed cortex of patients with intractable epilepsy and in cultured rat neurons. Int J Mol Med 2015; 35:597-606. [PMID: 25571999 PMCID: PMC4314424 DOI: 10.3892/ijmm.2015.2061] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Accepted: 12/22/2014] [Indexed: 02/07/2023] Open
Abstract
Mutations in RNA-binding Fox 1 (RBFOX1) are known to be associated with neurodevelopmental disorders including epilepsy, mental retardation and autism spectrum disorder. The deletion of the Rbfox1 gene in mice has been shown to result in heightened susceptibility to seizures. However, other studies have revealed mutations or the downregulation of RBFOX1 in specimens obtained from patients with epilepsy or malformations of cortical development (MCD). Generally, the expression of RBFOX1 varies according to tissue type. In this study, we demonstrated the upregulation of RBFOX1 protein in the cortex of patients with MCD and intractable epilepsy. Electrophysiological recordings of cultured rat cortical neurons with increased Rbfox1 expression also revealed a significantly increased amplitude of action potential (AP) and Na+ current density. Some of these neurons (26.32%) even displayed spontaneous, recurrent, epileptiform discharges (SREDs). Additionally, certain Rbfox1 target transcripts associated with epilepsy, including glutamate receptor, ionotropic, N-methyl D-aspartate 1 [Grin1, also known as N-methyl-D-aspartate receptor subunit NR1 (NMDAR1)], synaptosomal-associated protein, 25 kDa (SNAP-25 or Snap25) and sodium channel, voltage gated, type VIII, alpha subunit (Scn8a, also known as Nav1.6) were identified to be upregulated in these cultured cortical neurons with an upregulated Rbfox1 expression. These data suggest that the upregulation of RBFOX1 contributes to neuronal hyperexcitation and seizures. The upregulation of NMDAR1 (Grin1), SNAP-25 (Snap25) and Scn8a may thus be involved in Rbfox1-related neuronal hyperexcitation.
Collapse
Affiliation(s)
- Ming Wen
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, P.R. China
| | - Yong Yan
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing 400016, P.R. China
| | - Ning Yan
- Department of Neurology, University‑Town Hospital of Chongqing Medical University, Chongqing 401331, P.R. China
| | - Xiao Shan Chen
- Department of Neurology, Xi'an Central Hospital, Xi'an 710003, P.R. China
| | - Shi Yong Liu
- Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China
| | - Zhan Hui Feng
- Department of Neurology, Affiliated Hospital of Guiyang Medical University, Guiyang 550004, P.R. China
| |
Collapse
|
20
|
Silveira M, Silva T, Novaes P, Tirapelli L, Tirapelli D, Castro e Silva O. Ex Situ Regeneration of Liver Remnants Hypothermically Preserved for 24 Hours. Transplant Proc 2014; 46:1857-61. [DOI: 10.1016/j.transproceed.2014.05.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
21
|
Galanopoulou AS, Moshé SL. Does epilepsy cause a reversion to immature function? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 813:195-209. [PMID: 25012378 DOI: 10.1007/978-94-017-8914-1_16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Seizures have variable effects on brain. Numerous studies have examined the consequences of seizures, in light of the way that these may alter the susceptibility of the brain to seizures, promote epileptogenesis, or functionally alter brain leading to seizure-related comorbidities. In many -but not all- situations, seizures shift brain function towards a more immature state, promoting the birth of newborn neurons, altering the dendritic structure and neuronal connectivity, or changing neurotransmitter signaling towards more immature patterns. These effects depend upon many factors, including the seizure type, age of seizure occurrence, sex, and brain region studied. Here we discuss some of these findings proposing that these seizure-induced immature features do not simply represent rejuvenation of the brain but rather a de-synchronization of the homeostatic mechanisms that were in place to maintain normal physiology, which may contribute to epileptogenesis or the cognitive comorbidities.
Collapse
Affiliation(s)
- Aristea S Galanopoulou
- Saul R. Korey Department of Neurology, Dominick P. Purpura Department of Neuroscience, The Laboratory of Developmental Epilepsy, Comprehensive Einstein/Montefiore Epilepsy Center, Albert Einstein College of Medicine, 1410 Pelham Parkway South, Kennedy Center Rm 306, Bronx, NY, 10461, USA,
| | | |
Collapse
|
22
|
Ketzef M, Gitler D. Epileptic synapsin triple knockout mice exhibit progressive long-term aberrant plasticity in the entorhinal cortex. ACTA ACUST UNITED AC 2012; 24:996-1008. [PMID: 23236212 DOI: 10.1093/cercor/bhs384] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Studying epileptogenesis in a genetic model can facilitate the identification of factors that promote the conversion of a normal brain into one chronically prone to seizures. Synapsin triple-knockout (TKO) mice exhibit adult-onset epilepsy, thus allowing the characterization of events as preceding or following seizure onset. Although it has been proposed that a congenital reduction in inhibitory transmission is the underlying cause for epilepsy in these mice, young TKO mice are asymptomatic. We report that the genetic lesion exerts long-term progressive effects that extend well into adulthood. Although inhibitory transmission is initially reduced, it is subsequently strengthened relative to its magnitude in control mice, so that the excitation to inhibition balance in adult TKOs is inverted in favor of inhibition. In parallel, we observed long-term alterations in synaptic depression kinetics of excitatory transmission and in the extent of tonic inhibition, illustrating adaptations in synaptic properties. Moreover, age-dependent acceleration of the action potential did not occur in TKO cortical pyramidal neurons, suggesting wide-ranging secondary changes in brain excitability. In conclusion, although congenital impairments in inhibitory transmission may initiate epileptogenesis in the synapsin TKO mice, we suggest that secondary adaptations are crucial for the establishment of this epileptic network.
Collapse
Affiliation(s)
- Maya Ketzef
- Department of Physiology and Cell Biology, Faculty of Health Sciences and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | | |
Collapse
|
23
|
Hwang SK, Hirose S. Genetics of temporal lobe epilepsy. Brain Dev 2012; 34:609-16. [PMID: 22105092 DOI: 10.1016/j.braindev.2011.10.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2011] [Revised: 10/14/2011] [Accepted: 10/22/2011] [Indexed: 01/10/2023]
Abstract
The most common partial epilepsy, temporal lobe epilepsy (TLE) consists of a heterogeneous group of seizure disorders originating in the temporal lobe. TLE had been thought to develop as a result of acquired structural problems in the temporal lobe. During the past two decades, there has been growing evidence of the important influence of genetic factors, and familial and non-lesional TLE have been increasingly described. Here, we focus on the genetics of TLE and review related genes which have been studied recently. Although its molecular mechanisms are still poorly understood, TLE genetics is a fertile field, awaiting more research.
Collapse
Affiliation(s)
- Su-Kyeong Hwang
- Department of Pediatrics, School of Medicine, Fukuoka University, Fukuoka, Japan
| | | |
Collapse
|