1
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González-Arnay E, Pérez-Santos I, Jiménez-Sánchez L, Cid E, Gal B, de la Prida LM, Cavada C. Immunohistochemical field parcellation of the human hippocampus along its antero-posterior axis. Brain Struct Funct 2024; 229:359-385. [PMID: 38180568 PMCID: PMC10917878 DOI: 10.1007/s00429-023-02725-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 10/15/2023] [Indexed: 01/06/2024]
Abstract
The primate hippocampus includes the dentate gyrus, cornu ammonis (CA), and subiculum. CA is subdivided into four fields (CA1-CA3, plus CA3h/hilus of the dentate gyrus) with specific pyramidal cell morphology and connections. Work in non-human mammals has shown that hippocampal connectivity is precisely patterned both in the laminar and longitudinal axes. One of the main handicaps in the study of neuropathological semiology in the human hippocampus is the lack of clear laminar and longitudinal borders. The aim of this study was to explore a histochemical segmentation of the adult human hippocampus, integrating field (medio-lateral), laminar, and anteroposterior longitudinal patterning. We provide criteria for head-body-tail field and subfield parcellation of the human hippocampus based on immunodetection of Rabphilin3a (Rph3a), Purkinje-cell protein 4 (PCP4), Chromogranin A and Regulation of G protein signaling-14 (RGS-14). Notably, Rph3a and PCP4 allow to identify the border between CA3 and CA2, while Chromogranin A and RGS-14 give specific staining of CA2. We also provide novel histological data about the composition of human-specific regions of the anterior and posterior hippocampus. The data are given with stereotaxic coordinates along the longitudinal axis. This study provides novel insights for a detailed region-specific parcellation of the human hippocampus useful for human brain imaging and neuropathology.
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Affiliation(s)
- Emilio González-Arnay
- Department of Anatomy, Histology and Neuroscience, Universidad Autónoma de Madrid, Madrid, Spain
- Department of Basic Medical Science-Division of Human Anatomy, Universidad de La Laguna, Santa Cruz de Tenerife, Canary Islands, Spain
| | - Isabel Pérez-Santos
- Department of Anatomy, Histology and Neuroscience, Universidad Autónoma de Madrid, Madrid, Spain
| | - Lorena Jiménez-Sánchez
- Department of Anatomy, Histology and Neuroscience, Universidad Autónoma de Madrid, Madrid, Spain
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Elena Cid
- Instituto Cajal, CSIC, Madrid, Spain
| | - Beatriz Gal
- Instituto Cajal, CSIC, Madrid, Spain
- Universidad CEU-San Pablo, Madrid, Spain
| | | | - Carmen Cavada
- Department of Anatomy, Histology and Neuroscience, Universidad Autónoma de Madrid, Madrid, Spain.
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2
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Vergaelen M, Manzella S, Vonck K, Craey E, Spanoghe J, Sprengers M, Carrette E, Wadman WJ, Delbeke J, Boon P, Larsen LE, Raedt R. Increased Dentate Gyrus Excitability in the Intrahippocampal Kainic Acid Mouse Model for Temporal Lobe Epilepsy. Int J Mol Sci 2024; 25:660. [PMID: 38203829 PMCID: PMC10779277 DOI: 10.3390/ijms25010660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/29/2023] [Accepted: 01/02/2024] [Indexed: 01/12/2024] Open
Abstract
The intrahippocampal kainic acid (IHKA) mouse model is an extensively used in vivo model to investigate the pathophysiology of mesial temporal lobe epilepsy (mTLE) and to develop novel therapies for drug-resistant epilepsy. It is characterized by profound hippocampal sclerosis and spontaneously occurring seizures with a major role for the injected damaged hippocampus, but little is known about the excitability of specific subregions. The purpose of this study was to electrophysiologically characterize the excitability of hippocampal subregions in the chronic phase of the induced epilepsy in the IHKA mouse model. We recorded field postsynaptic potentials (fPSPs) after electrical stimulation in the CA1 region and in the dentate gyrus (DG) of hippocampal slices of IHKA and healthy mice using a multielectrode array (MEA). In the DG, a significantly steeper fPSP slope was found, reflecting higher synaptic strength. Population spikes were more prevalent with a larger spatial distribution in the IHKA group, reflecting a higher degree of granule cell output. Only minor differences were found in the CA1 region. These results point to increased neuronal excitability in the DG but not in the CA1 region of the hippocampus of IHKA mice. This method, in which the excitability of hippocampal slices from IHKA mice is investigated using a MEA, can now be further explored as a potential new model to screen for new interventions that can restore DG function and potentially lead to novel therapies for mTLE.
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Affiliation(s)
- Marijke Vergaelen
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
| | - Simona Manzella
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
| | - Kristl Vonck
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
| | - Erine Craey
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
| | - Jeroen Spanoghe
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
| | - Mathieu Sprengers
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
| | - Evelien Carrette
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
| | - Wytse Jan Wadman
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
| | - Jean Delbeke
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
| | - Paul Boon
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
| | - Lars Emil Larsen
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
- MEDISIP, Department of Electronics and Information Systems, Ghent University, 9000 Ghent, Belgium
| | - Robrecht Raedt
- 4BRAIN, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium
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3
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Giachetti I, Padelli F, Aquino D, Garbelli R, De Santis D, Rossini L, Deleo F, Pascuzzo R, Coras R, Marucci G, Tringali G, Maccagnano C, De Curtis M, Bruzzone MG, Didato G. Role of NODDI in the MRI Characterization of Hippocampal Abnormalities in Temporal Lobe Epilepsy: Clinico-histopathologic Correlations. Neurology 2022; 98:e1771-e1782. [PMID: 35256485 PMCID: PMC9071371 DOI: 10.1212/wnl.0000000000200140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 01/18/2022] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The identification of possible hippocampal alterations is a crucial point for the diagnosis and therapy of patients with unilateral temporal lobe epilepsy (TLE). OBJECTIVE To investigate the role of Neurite Orientation Dispersion and Density Imaging (NODDI), compared to Diffusion Tensor Imaging (DTI), in the comprehension of hippocampal microstructure in TLE. METHODS DTI and NODDI metrics were calculated in the hippocampi of adult patients with TLE, with and without histology-confirmed hippocampal sclerosis (HS), and in age/sex-matched healthy controls (HC). Diffusion metrics and hippocampal volumes of pathologic side were compared within subjects and between subjects among HS, non-HS, and HC groups. Diffusion metrics were also correlated with hippocampal volume and patients' clinical features. After surgery, hippocampal specimens were processed for neuropathology examinations. RESULTS Fifteen patients with TLE (9 with and 6 without HS) and 11 HC were included. Hippocampal analyses resulted in significant increase in FA (fractional anisotropy) and MD (mean diffusivity, mm2/s × 10-3), decrease in ODI (orientation dispersion index) comparing the pathologic side of patients with HS vs: (1) their relative non-pathological side (0.203 vs 0.183, 0.825 vs 0.724, 0.366 vs 0.443, respectively); (2) the pathologic side of patients without HS (0.203 vs 0.169, 0.825 vs 0.745, 0.366 vs 0.453, respectively); (3) HC (0.203 vs 0.172, 0.825 vs 0.729, 0.366 vs 0.447, respectively). Moreover, ND (neurite density) was significantly decreased comparing both hippocampi of patients with HS (0.416 vs 0.460). A significant increase in fiso (free-water isotropic volume fraction) was found in the comparison of pathologic hippocampi of patients with HS vs: (1) non-pathological hippocampi of patients with HS (0.323 vs 0.258); (2) HC (0.323 vs 0.226). Hippocampal volume of all patients with TLE negatively correlated with MD (r = -0.746, p = 0.0145) and positively correlated with ODI (r = 0.719, p = 0.0145). Fiso and ND of sclerotic hippocampi positively correlated with disease duration (r = 0.684, p = 0.0424 and r = 0.670, p = 0.0486, respectively). Immunohistochemistry in sclerotic hippocampal specimens revealed neuronal loss in pyramidal layer and fiber reorganization at the level of stratum lacunosum-moleculare confirming ODI and ND metrics. DISCUSSION This study shows the capability of diffusion-MRI metrics to detect hippocampal microstructural alterations. Among them, ODI seems to better highlight the fiber reorganization observed by neuropathology in sclerotic hippocampi.
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Affiliation(s)
- Isabella Giachetti
- From the Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Francesco Padelli
- From the Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy.,Scientific Department, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Domenico Aquino
- From the Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Rita Garbelli
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Dalia De Santis
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Laura Rossini
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Francesco Deleo
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Riccardo Pascuzzo
- From the Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Roland Coras
- Department of Neuropathology, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Gianluca Marucci
- Neuropathology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Giovanni Tringali
- Neurosurgery Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Carmelo Maccagnano
- From the Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Marco De Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Maria Grazia Bruzzone
- From the Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
| | - Giuseppe Didato
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milano, Italy
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Toscano ECDB, Vieira ÉLM, Portela ACDC, Reis JLJ, Caliari MV, Giannetti AV, Gonçalves AP, Siqueira JM, Suemoto CK, Leite REP, Nitrini R, Teixeira AL, Rachid MA. Bcl-2/Bax ratio increase does not prevent apoptosis of glia and granular neurons in patients with temporal lobe epilepsy. Neuropathology 2019; 39:348-357. [PMID: 31392787 DOI: 10.1111/neup.12592] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 06/06/2019] [Accepted: 07/08/2019] [Indexed: 12/13/2022]
Abstract
Temporal lobe epilepsy (TLE) is usually associated with hippocampal sclerosis (HS), characterized by gliosis and neuronal loss, mainly in the cornus ammonis (CA). Regardless the type of HS, gliosis is associated with neuronal loss. Indeed, glial reactivation seems to induce both neuronal and glial apoptosis. Anti-apoptotic mechanisms are also activated in order to contain the cell death in chronic epilepsy. However, the role of the intrinsic apoptosis pathway in human TLE is unclear, mainly in relation to glial death. The purpose of this study was to evaluate the reactive gliosis areas in parallel with Bcl-2/Bax ratio and active caspase 3 immunoreactivity in hippocampi of TLE patients in comparison with control hippocampi. We also sought to investigate whether the levels of these markers were correlated with TLE clinical parameters. Paraffin-embedded sclerotic and control hippocampi were collected for immunohistochemical analyses of glial fibrillary acidic protein (GFAP), human leucocyte antigen DR (HLA-DR), neuronal nuclei protein (NeuN), Bax, Bcl-2 and active caspase 3. Sclerotic hippocampi presented higher immunoreactivity areas of GFAP and HLA-DR than controls, with similar values in HS types 1 and 2. Bcl-2 protein expression was increased in epileptic hippocampi, while Bax expression was similar to controls. Despite Bcl2/Bax ratio increase, granular neurons and glia exhibited active caspase 3 expression in TLE hippocampi, while controls did not show staining for the same marker. In conclusion, glial and neuronal death is increased in sclerotic hippocampi, independently of HS type, and co-localized with gliosis. Furthermore, Bcl-2/Bax ratio increase does not prevent expression of active caspase 3 by glia and granular neurons in TLE.
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Affiliation(s)
- Eliana C de Brito Toscano
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Neuroscience Division, Interdisciplinary Laboratory of Medical Investigation, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Érica L M Vieira
- Neuroscience Division, Interdisciplinary Laboratory of Medical Investigation, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ana C D C Portela
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Joice L J Reis
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Marcelo V Caliari
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Alexandre V Giannetti
- Hospital das Clínicas, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ana P Gonçalves
- Hospital das Clínicas, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Nuclei of Advanced Epilepsy Treatment - Felício Rocho Hospital, Belo Horizonte, Brazil
| | - José M Siqueira
- Nuclei of Advanced Epilepsy Treatment - Felício Rocho Hospital, Belo Horizonte, Brazil
| | - Claudia K Suemoto
- Laboratório de Fisiopatologia no Envelhecimento, Universidade de São Paulo, São Paulo, Brazil
| | - Renata E P Leite
- Laboratório de Fisiopatologia no Envelhecimento, Universidade de São Paulo, São Paulo, Brazil
| | - Ricardo Nitrini
- Laboratório de Fisiopatologia no Envelhecimento, Universidade de São Paulo, São Paulo, Brazil
| | - Antônio L Teixeira
- Neuroscience Division, Interdisciplinary Laboratory of Medical Investigation, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Neuropsychiatry Program, Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Milene A Rachid
- Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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5
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Li M, Cui L, Feng X, Wang C, Zhang Y, Wang L, Ding Y, Zhao T. Losmapimod Protected Epileptic Rats From Hippocampal Neuron Damage Through Inhibition of the MAPK Pathway. Front Pharmacol 2019; 10:625. [PMID: 31231220 PMCID: PMC6565798 DOI: 10.3389/fphar.2019.00625] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/15/2019] [Indexed: 12/15/2022] Open
Abstract
Objective: This research aimed to validate the therapeutic effect of losmapimod and explore the underlying mechanism in its treatment of epilepsy. Methods: A rat model of epilepsy was constructed with an injection of pilocarpine. Microarray analysis was performed to screen aberrantly expressed mRNAs and activated signaling pathways between epileptic rats and normal controls. A TdT-mediated dUTP nick-end labeling (TUNEL) assay was used to identify cell apoptosis. Hippocampal cytoarchitecture was visualized with Nissl staining. The secretion of inflammatory factors as well as the marker proteins in the mitogen-activated protein kinase (MAPK) pathway were detected by Western blot. A Morris water maze navigation test evaluated the rats’ cognitive functions. Results: Activation of the MAPK signaling pathway was observed in epilepsy rats. A decrease in the MAPK phosphorylation level by application of losmapimod protected against epilepsy by reducing neuron loss. Losmapimod effectively improved memory, reduced the frequency of seizures, protected the neuron from damage, and limited the apoptosis of neurons in epilepsy rats. Conclusion: The application of losmapimod could partly reverse the development of epilepsy.
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Affiliation(s)
- Min Li
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Lexiang Cui
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Xuemin Feng
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Chao Wang
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
| | - Yinmeng Zhang
- Major in Clinical Medicine, Medical College of Nanchang University, Nanchang, China
| | - Lijie Wang
- Department of Traditional Chinese Medicine, General Hospital of FAW, Fourth Hospital of Jilin University, Changchuan, China
| | - Ying Ding
- Department of Radiology, The First Hospital of Jilin University, Changchun, China
| | - Teng Zhao
- Department of Neurology, The First Hospital of Jilin University, Changchun, China
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6
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Marchionni I, Oberoi M, Soltesz I, Alexander A. Ripple-related firing of identified deep CA1 pyramidal cells in chronic temporal lobe epilepsy in mice. Epilepsia Open 2019; 4:254-263. [PMID: 31168492 PMCID: PMC6546014 DOI: 10.1002/epi4.12310] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 01/02/2019] [Accepted: 01/19/2019] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE Temporal lobe epilepsy (TLE) is often associated with memory deficits. Reactivation of memory traces in the hippocampus occurs during sharp-wave ripples (SWRs; 140-250 Hz). To better understand the mechanisms underlying high-frequency oscillations and cognitive comorbidities in epilepsy, we evaluated how rigorously identified deep CA1 pyramidal cells (dPCs) discharge during SWRs in control and TLE mice. METHODS We used the unilateral intraamygdala kainate model of TLE in video-electroencephalography (EEG) verified chronically epileptic adult mice. Local field potential and single-cell recordings were performed using juxtacellular recordings from awake control and TLE mice resting on a spherical treadmill, followed by post hoc identification of the recorded cells. RESULTS Hippocampal SWRs in TLE mice occurred with increased intraripple frequency compared to control mice. The frequency of SWR events was decreased, whereas the overall frequency of SWRs, interictal epileptiform discharges, and high-frequency ripples (250-500 Hz) together was not altered. CA1 dPCs in TLE mice showed significantly increased firing during ripples as well as between the ripple events. The strength of ripple modulation of dPC discharges increased in TLE without alteration of the preferred phase of firing during the ripple waves. SIGNIFICANCE These juxtacellular electrophysiology data obtained from identified CA1 dPCs from chronically epileptic mice are in general agreement with recent findings indicating distortion of normal firing patterns during offline SWRs as a mechanism underlying deficits in memory consolidation in epilepsy. Because the primary seizure focus in our experiments was in the amygdala and we recorded from the CA1 region, these results are also in agreement with the presence of altered high-frequency oscillations in areas of secondary seizure spread.
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Affiliation(s)
- Ivan Marchionni
- Department of Anatomy & NeurobiologyUniversity of CaliforniaIrvineCalifornia
- Department of Biomedical Sciences and Padova Neuroscience CenterUniversity of PadovaPadovaItaly
| | - Michelle Oberoi
- Department of Anatomy & NeurobiologyUniversity of CaliforniaIrvineCalifornia
- University of CaliforniaRiverside School of MedicineRiversideCalifornia
| | - Ivan Soltesz
- Department of Anatomy & NeurobiologyUniversity of CaliforniaIrvineCalifornia
- Department of NeurosurgeryStanford UniversityStanfordCalifornia
| | - Allyson Alexander
- Department of NeurosurgeryAnschutz School of MedicineUniversity of Colorado DenverAuroraColorado
- Department of NeurosurgeryChildren's Hospital ColoradoAuroraColorado
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7
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Gillmann C, Coras R, Rössler K, Doerfler A, Uder M, Blümcke I, Bäuerle T. Ultra-high field MRI of human hippocampi: Morphological and multiparametric differentiation of hippocampal sclerosis subtypes. PLoS One 2018; 13:e0196008. [PMID: 29668721 PMCID: PMC5906020 DOI: 10.1371/journal.pone.0196008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 04/04/2018] [Indexed: 12/23/2022] Open
Abstract
The aim of the present study is to differentiate subtypes of hippocampal sclerosis (HS) using ex vivo ultra-high field magnetic resonance imaging (MRI). Included were 14 surgically resected hippocampi of patients with medically intractable temporal lobe epilepsy. The resected hippocampi were histologically categorized into subtypes of hippocampal sclerosis (HS type 1 (n = 10), HS type 2 (n = 2) and no-HS (n = 2)) and subsequently scanned on a preclinical 7T MRI acquiring T2-weighted morphology, relaxometry and diffusion tensor imaging. On the morphological images, the pyramidal cell layer (PCL) of the hippocampus was segmented and the following parameters were derived: T2 signal intensity, T1-, T2- and T2*-relaxation times, apparent diffusion coefficient (ADC), fractional anisotropy (FA) and mean diffusivity (MD). Furthermore, the area of the PCL was determined, as well as the parameter product which refers to the widths of the PCL parallel and perpendicular to the stratum moleculare. Spearman correlation coefficient was used to demonstrate relationships between MR-parameters and type of sclerosis. In comparison to no-HS specimens, the PCL was significantly narrower in HS type 1 and HS type 2 hippocampi. This narrowing affected the entire cornu ammonis sector (CA) 1 in HS type 1, while it was limited to the upper half of CA1 in direction to CA2 in HS type 2. The parameter product median increased from 0.43 to 1.67 and 2.91 mm2 for HS type 1, HS type 2 and no-HS, respectively. Correlation coefficients were significant for the PCL parameters product (0.73), area (0.71), T2*-time (-0.67), FA (0.65) and ADC (0.55). Our initial results suggest that HS type 1, HS type 2 and no-HS subtypes can be distinguished from each other using ex vivo UHF MRI based on T2-weighted morphologic images and the assessment of the parameter product. Upon clinical translation, UHF-MRI may provide a promising technique for the preoperative differentiation of HS subtypes in patients.
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Affiliation(s)
- Clarissa Gillmann
- Institute of Radiology, University Hospital Erlangen, Erlangen, Germany
- * E-mail:
| | - Roland Coras
- Institute of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Karl Rössler
- Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany
| | - Arnd Doerfler
- Department of Neuroradiology, University Hospital Erlangen, Erlangen, Germany
| | - Michael Uder
- Institute of Radiology, University Hospital Erlangen, Erlangen, Germany
| | - Ingmar Blümcke
- Institute of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Tobias Bäuerle
- Institute of Radiology, University Hospital Erlangen, Erlangen, Germany
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8
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Tai XY, Bernhardt B, Thom M, Thompson P, Baxendale S, Koepp M, Bernasconi N. Review: Neurodegenerative processes in temporal lobe epilepsy with hippocampal sclerosis: Clinical, pathological and neuroimaging evidence. Neuropathol Appl Neurobiol 2018; 44:70-90. [DOI: 10.1111/nan.12458] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/07/2017] [Indexed: 12/14/2022]
Affiliation(s)
- X. Y. Tai
- Division of Neuropathology and Department of Clinical and Experimental Epilepsy; UCL Institute of Neurology; London UK
| | - B. Bernhardt
- Neuroimaging of Epilepsy Laboratory; McConnell Brain Imaging Centre; Montreal Neurological Institute; McGill University; Montreal Quebec Canada
- Multimodal Imaging and Connectome Analysis Lab; Montreal Neurological Institute; Montreal Neurological Institute; McGill University; Montreal Quebec Canada
| | - M. Thom
- Division of Neuropathology and Department of Clinical and Experimental Epilepsy; UCL Institute of Neurology; London UK
| | - P. Thompson
- Department of Clinical and Experimental Epilepsy; UCL Institute of Neurology; London UK
| | - S. Baxendale
- Department of Clinical and Experimental Epilepsy; UCL Institute of Neurology; London UK
| | - M. Koepp
- Department of Clinical and Experimental Epilepsy; UCL Institute of Neurology; London UK
| | - N. Bernasconi
- Neuroimaging of Epilepsy Laboratory; McConnell Brain Imaging Centre; Montreal Neurological Institute; McGill University; Montreal Quebec Canada
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9
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Sanon NT, Gagné J, Wolf DC, Aboulamer S, Bosoi CM, Simard A, Messiet E, Desgent S, Carmant L. Favorable adverse effect profile of brivaracetam vs levetiracetam in a preclinical model. Epilepsy Behav 2018; 79:117-125. [PMID: 29287214 DOI: 10.1016/j.yebeh.2017.11.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/15/2017] [Accepted: 11/19/2017] [Indexed: 10/18/2022]
Abstract
Levetiracetam (LEV), and its newer selective analog brivaracetam (BRV), are two seizure medications that share an innovative mechanism of action targeting the Synaptic Vesicle Protein 2A (SV2A), altering neurotransmitter release and decreasing seizure frequency. Behavioral changes are the most significant adverse effects reported by patients taking LEV. We hypothesize that BRV, the more potent SV2A analog, could exert less behavioral side effects, as it requires lower doses than LEV. Using Kainic Acid (KA)-treated and control rats, we measured adverse behavioral effect profiles of LEV, BRV, or Saline, on social and nonsocial behaviors. Our data indicate that both tested drugs had no effect on locomotion, anxiety levels, fear learning, depression-like behavior, and memory retention in rats. However, when considering social interactions, we first confirmed the epilepsy-induced strong increase in aggressive behaviors and specific hippocampal neuronal loss. We furthermore observed, in Sham rats, that LEV-treated animals were 2 times faster to attack at first encounter, had 5 times more aggressive behaviors, and had significantly less social behaviors than control rats. In all circumstances, BRV rats behaved like Saline rats, suggesting that BRV treatment in rats leads to significantly less aggressive behaviors than LEV treatment at the doses used, while there are limited differential effects between these two drugs on other types of behaviors. Since increased aggressiveness has been reported in patients well controlled on LEV, this study indicates based on our findings, that BRV could represent an effective alternative to LEV to limit aggressiveness problems due to this antiepileptic drug (AED) therapy.
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Affiliation(s)
- Nathalie T Sanon
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada.
| | - Jonathan Gagné
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada; Département de Sciences Biomédicales, Université de Montréal, Québec, Canada
| | - Daniele C Wolf
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada; Département de Neurosciences, Faculté de Médecine, Université de Montréal, Québec, Canada
| | - Soumia Aboulamer
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada
| | - Ciprian M Bosoi
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada
| | - Alexe Simard
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada
| | - Estelle Messiet
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada
| | - Sébastien Desgent
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada; Département de Neurosciences, Faculté de Médecine, Université de Montréal, Québec, Canada
| | - Lionel Carmant
- Centre de Recherche, Centre Hospitalier Universitaire CHU-Sainte-Justine, Québec, Canada; Département de Neurosciences, Faculté de Médecine, Université de Montréal, Québec, Canada.
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10
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Comper SM, Jardim AP, Corso JT, Gaça LB, Noffs MHS, Lancellotti CLP, Cavalheiro EA, Centeno RS, Yacubian EMT. Impact of hippocampal subfield histopathology in episodic memory impairment in mesial temporal lobe epilepsy and hippocampal sclerosis. Epilepsy Behav 2017; 75:183-189. [PMID: 28873362 DOI: 10.1016/j.yebeh.2017.08.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 08/06/2017] [Accepted: 08/07/2017] [Indexed: 12/30/2022]
Abstract
OBJECTIVE The objective of the study was to analyze preoperative visual and verbal episodic memories in a homogeneous series of patients with mesial temporal lobe epilepsy (MTLE) and unilateral hippocampal sclerosis (HS) submitted to corticoamygdalohippocampectomy and its association with neuronal cell density of each hippocampal subfield. METHODS The hippocampi of 72 right-handed patients were collected and prepared for histopathological examination. Hippocampal sclerosis patterns were determined, and neuronal cell density was calculated. Preoperatively, two verbal and two visual memory tests (immediate and delayed recalls) were applied, and patients were divided into two groups, left and right MTLE (36/36). RESULTS There were no statistical differences between groups regarding demographic and clinical data. Cornu Ammonis 4 (CA4) neuronal density was significantly lower in the right hippocampus compared with the left (p=0.048). The groups with HS presented different memory performance - the right HS were worse in visual memory test [Complex Rey Figure, immediate (p=0.001) and delayed (p=0.009)], but better in one verbal task [RAVLT delayed (p=0.005)]. Multiple regression analysis suggested that the verbal memory performance of the group with left HS was explained by CA1 neuronal density since both tasks were significantly influenced by CA1 [Logical Memory immediate recall (p=0.050) and Logical Memory and RAVLT delayed recalls (p=0.004 and p=0.001, respectively)]. For patients with right HS, both CA1 subfield integrity (p=0.006) and epilepsy duration (p=0.012) explained Complex Rey Figure immediate recall performance. Ultimately, epilepsy duration also explained the performance in the Complex Rey Figure delayed recall (p<0.001). SIGNIFICANCE Cornu Ammonis 1 (CA1) hippocampal subfield was related to immediate and delayed recalls of verbal memory tests in left HS, while CA1 and epilepsy duration were associated with visual memory performance in patients with right HS.
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Affiliation(s)
- Sandra Mara Comper
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Anaclara Prada Jardim
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
| | - Jeana Torres Corso
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Larissa Botelho Gaça
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Maria Helena Silva Noffs
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | | | - Esper Abrão Cavalheiro
- Neuroscience Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Ricardo Silva Centeno
- Neurosurgery Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Elza Márcia Targas Yacubian
- Clinical Neurology Sector, Department of Neurology and Neurosurgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
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11
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Ivanov AD, Zaitsev AV. NMDAR-independent hippocampal long-term depression impairment after status epilepticus in a lithium-pilocarpine model of temporal lobe epilepsy. Synapse 2017; 71. [PMID: 28432779 DOI: 10.1002/syn.21982] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 03/29/2017] [Accepted: 04/13/2017] [Indexed: 11/07/2022]
Abstract
Temporal lobe epilepsy is usually associated with cognitive decline and memory deficits. Despite numerous existing studies on various animal models, the mechanisms of these deficits remain largely unclear. A specific form of long-term synaptic efficacy changes-long-term depression (LTD)-is thought to play an important role in memory formation and learning. However, extremely little is known about the possible alteration of LTD induction and dynamics after a status epilepticus (SE). In this work, we investigated the acute and delayed effects of lithium-pilocarpine-induced SE on NMDAR-dependent and NMDAR-independent hippocampal LTD in vitro. We found that SE affected the NMDAR-dependent and NMDAR-independent forms of LTD in different manners. The NMDAR-dependent form of LTD was almost intact 3 days after SE, but it switched from a predominantly presynaptic to a more postsynaptic locus of expression. In contrast, the NMDAR-independent LTD in the hippocampal Schaffer collaterals-CA1 synapses was fully abolished 3 days after SE. Our results emphasize the role of non-NMDA-dependent synaptic plasticity changes in the processes of epileptogenesis and the potential for therapy development.
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Affiliation(s)
- Andrey D Ivanov
- Neurophysiology of Learning Laboratory, Institute of Higher Nervous Activity and Neurophysiology of the Russian Academy of Sciences (IHNA), Moscow, Russia
| | - Aleksey V Zaitsev
- Molecular Mechanisms of Neuronal Interactions Laboratory, Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (IEPhB), Saint Petersburg, Russia.,Institute of Experimental Medicine, Federal Almazov North-West Medical Research Centre, Saint Petersburg, Russia
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12
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Prada Jardim A, Liu J, Baber J, Michalak Z, Reeves C, Ellis M, Novy J, de Tisi J, McEvoy A, Miserocchi A, Targas Yacubian EM, Sisodiya S, Thompson P, Thom M. Characterising subtypes of hippocampal sclerosis and reorganization: correlation with pre and postoperative memory deficit. Brain Pathol 2017; 28:143-154. [PMID: 28380661 PMCID: PMC5893935 DOI: 10.1111/bpa.12514] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 03/28/2017] [Indexed: 01/16/2023] Open
Abstract
Neuropathological subtypes of hippocampal sclerosis (HS) in temporal lobe epilepsy (The 2013 International League Against Epilepsy classification) are based on the qualitative assessment of patterns of neuronal loss with NeuN. In practice, some cases appear indeterminate between type 1 (CA1 and CA4 loss) and type 2 HS (CA1 loss) and we predicted that MAP2 would enable a more stringent classification. HS subtypes, as well as the accompanying alteration of axonal networks, regenerative capacity and neurodegeneration have been previously correlated with outcome and memory deficits and may provide prognostic clinical information. We selected 92 cases: 52 type 1 HS, 15 type 2 HS, 18 indeterminate‐HS and 7 no‐HS. Quantitative analysis was carried out on NeuN and MAP2 stained sections and a labeling index (LI) calculated for six hippocampal subfields. We also evaluated hippocampal regenerative activity (MCM2, nestin, olig2, calbindin), degeneration (AT8/phosphorylated tau) and mossy‐fiber pathway re‐organization (ZnT3). Pathology measures were correlated with clinical epilepsy history, memory and naming test scores and postoperative outcomes, at 1 year following surgery. MAP2 LI in indeterminate‐HS was statistically similar to type 2 HS but this clustering was not shown with NeuN. Moderate verbal and visual memory deficits were noted in all HS types, including 54% and 69% of type 2 HS. Memory deficits correlated with several pathology factors including lower NeuN or MAP2 LI in CA4, CA1, dentate gyrus (DG) and subiculum and poor preservation of the mossy fiber pathway. Decline in memory at 1 year associated with AT8 labeling in the subiculum and DG but not HS type. We conclude that MAP2 is a helpful addition in the classification of HS in some cases. Classification of HS subtype, however, did not significantly correlate with outcome or pre‐ or postoperative memory dysfunction, which was associated with multiple pathology factors including hippocampal axonal pathways, regenerative capacity and degenerative changes.
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Affiliation(s)
- Anaclara Prada Jardim
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Department of Neurology and Neurosurgery, Universidade Federal de Sao Paulo, UNIFESP, Sao Paulo, Brazil
| | - Joan Liu
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neuropathology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | - Jack Baber
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK
| | - Zuzanna Michalak
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neuropathology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | - Cheryl Reeves
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neuropathology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | - Matthew Ellis
- Departments of Neuropathology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | - Jan Novy
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK.,Service de Neurologie, Département des Neurosciences Cliniques, CHUV, University of Lausanne, Switzerland
| | - Jane de Tisi
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK
| | - Andrew McEvoy
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | - Anna Miserocchi
- Departments of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
| | | | - Sanjay Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK.,Epilepsy Society, Epilepsy Society Research Centre, Buckinghamshire, SL9 0RJ, UK
| | - Pamela Thompson
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neuropsychology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK.,Epilepsy Society, Epilepsy Society Research Centre, Buckinghamshire, SL9 0RJ, UK
| | - Maria Thom
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London, WCN1BG, UK.,Departments of Neuropathology, National Hospital for Neurology and Neurosurgery, Queen Square, London, WCN1BG, UK
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13
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Abstract
The hippocampus has a pivotal role in learning and in the formation and consolidation of memory and is critically involved in the regulation of emotion, fear, anxiety, and stress. Studies of the hippocampus have been central to the study of memory in humans and in recent years, the regional specialization and organization of hippocampal functions have been elucidated in experimental models and in human neurological and psychiatric diseases. The hippocampus has long been considered a classic model for the study of neuroplasticity as many examples of synaptic plasticity such as long-term potentiation and -depression have been identified and demonstrated in hippocampal circuits. Neuroplasticity is the ability to adapt and reorganize the structure or function to internal or external stimuli and occurs at the cellular, population, network or behavioral level and is reflected in the cytological and network architecture as well as in intrinsic properties of hippocampal neurons and circuits. The high degree of hippocampal neuroplasticity might, however, be also negatively reflected in the pronounced vulnerability of the hippocampus to deleterious conditions such as ischemia, epilepsy, chronic stress, neurodegeneration and aging targeting hippocampal structure and function and leading to cognitive deficits. Considering this framework of plasticity and vulnerability, we here review basic principles of hippocampal anatomy and neuroplasticity on various levels as well as recent findings regarding the functional organization of the hippocampus in light of the regional vulnerability in Alzheimer's disease, ischemia, epilepsy, neuroinflammation and aging.
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Affiliation(s)
- T Bartsch
- Department of Neurology, Memory Disorders and Plasticity Group, University Hospital Schleswig-Holstein, Kiel, Germany.
| | - P Wulff
- Institute of Physiology, Neurophysiology, University of Kiel, Olshausenstrasse 40, 24098 Kiel, Germany.
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