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Villaseñor PJ, Cortés-Servín D, Pérez-Moriel A, Aquiles A, Luna-Munguía H, Ramirez-Manzanares A, Coronado-Leija R, Larriva-Sahd J, Concha L. Multi-tensor diffusion abnormalities of gray matter in an animal model of cortical dysplasia. Front Neurol 2023; 14:1124282. [PMID: 37342776 PMCID: PMC10278582 DOI: 10.3389/fneur.2023.1124282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 04/18/2023] [Indexed: 06/23/2023] Open
Abstract
Focal cortical dysplasias are a type of malformations of cortical development that are a common cause of drug-resistant focal epilepsy. Surgical treatment is a viable option for some of these patients, with their outcome being highly related to complete surgical resection of lesions visible in magnetic resonance imaging (MRI). However, subtle lesions often go undetected on conventional imaging. Several methods to analyze MRI have been proposed, with the common goal of rendering subtle cortical lesions visible. However, most image-processing methods are targeted to detect the macroscopic characteristics of cortical dysplasias, which do not always correspond to the microstructural disarrangement of these cortical malformations. Quantitative analysis of diffusion-weighted MRI (dMRI) enables the inference of tissue characteristics, and novel methods provide valuable microstructural features of complex tissue, including gray matter. We investigated the ability of advanced dMRI descriptors to detect diffusion abnormalities in an animal model of cortical dysplasia. For this purpose, we induced cortical dysplasia in 18 animals that were scanned at 30 postnatal days (along with 19 control animals). We obtained multi-shell dMRI, to which we fitted single and multi-tensor representations. Quantitative dMRI parameters derived from these methods were queried using a curvilinear coordinate system to sample the cortical mantle, providing inter-subject anatomical correspondence. We found region- and layer-specific diffusion abnormalities in experimental animals. Moreover, we were able to distinguish diffusion abnormalities related to altered intra-cortical tangential fibers from those associated with radial cortical fibers. Histological examinations revealed myelo-architectural abnormalities that explain the alterations observed through dMRI. The methods for dMRI acquisition and analysis used here are available in clinical settings and our work shows their clinical relevance to detect subtle cortical dysplasias through analysis of their microstructural properties.
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Affiliation(s)
- Paulina J. Villaseñor
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
| | - David Cortés-Servín
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
| | | | - Ana Aquiles
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
| | - Hiram Luna-Munguía
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
| | | | - Ricardo Coronado-Leija
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, United States
| | - Jorge Larriva-Sahd
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
| | - Luis Concha
- Instituto de Neurobiología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, Mexico
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Assis-Mendonça GR, Athié MCP, Tamanini JVG, de Souza A, Zanetti GG, Araújo PAORDA, Ghizoni E, Tedeschi H, Alvim MKM, de Almeida VS, de Souza W, Coras R, Yasuda CL, Blümcke I, Vieira AS, Cendes F, Lopes-Cendes I, Rogerio F. Transcriptome analyses of the cortex and white matter of focal cortical dysplasia type II: Insights into pathophysiology and tissue characterization. Front Neurol 2023; 14:1023950. [PMID: 37006485 PMCID: PMC10050872 DOI: 10.3389/fneur.2023.1023950] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 01/26/2023] [Indexed: 03/17/2023] Open
Abstract
IntroductionFocal cortical dysplasia (FCD) is a common cause of pharmacoresistant epilepsy. According to the 2022 International League Against Epilepsy classification, FCD type II is characterized by dysmorphic neurons (IIa and IIb) and may be associated with balloon cells (IIb). We present a multicentric study to evaluate the transcriptomes of the gray and white matters of surgical FCD type II specimens. We aimed to contribute to pathophysiology and tissue characterization.MethodsWe investigated FCD II (a and b) and control samples by performing RNA-sequencing followed by immunohistochemical validation employing digital analyses.ResultsWe found 342 and 399 transcripts differentially expressed in the gray matter of IIa and IIb lesions compared to controls, respectively. Cholesterol biosynthesis was among the main enriched cellular pathways in both IIa and IIb gray matter. Particularly, the genes HMGCS1, HMGCR, and SQLE were upregulated in both type II groups. We also found 12 differentially expressed genes when comparing transcriptomes of IIa and IIb lesions. Only 1 transcript (MTRNR2L12) was significantly upregulated in FCD IIa. The white matter in IIa and IIb lesions showed 2 and 24 transcripts differentially expressed, respectively, compared to controls. No enriched cellular pathways were detected. GPNMB, not previously described in FCD samples, was upregulated in IIb compared to IIa and control groups. Upregulations of cholesterol biosynthesis enzymes and GPNMB genes in FCD groups were immunohistochemically validated. Such enzymes were mainly detected in both dysmorphic and normal neurons, whereas GPNMB was observed only in balloon cells.DiscussionOverall, our study contributed to identifying cortical enrichment of cholesterol biosynthesis in FCD type II, which may correspond to a neuroprotective response to seizures. Moreover, specific analyses in either the gray or the white matter revealed upregulations of MTRNR2L12 and GPNMB, which might be potential neuropathological biomarkers of a cortex chronically exposed to seizures and of balloon cells, respectively.
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Affiliation(s)
- Guilherme Rossi Assis-Mendonça
- Department of Pathology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Maria Carolina Pedro Athié
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - João Vitor Gerdulli Tamanini
- Department of Pathology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Arethusa de Souza
- Department of Pathology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
| | - Gabriel Gerardini Zanetti
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Patrícia Aline Oliveira Ribeiro de Aguiar Araújo
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Enrico Ghizoni
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Helder Tedeschi
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Marina Koutsodontis Machado Alvim
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Vanessa Simão de Almeida
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Welliton de Souza
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Roland Coras
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Clarissa Lin Yasuda
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - André Schwambach Vieira
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Fernando Cendes
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Neurology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Iscia Lopes-Cendes
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- Department of Translational Medicine, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Fabio Rogerio
- Department of Pathology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, SP, Brazil
- The Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, SP, Brazil
- *Correspondence: Fabio Rogerio
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Gennari AG, Cserpan D, Stefanos-Yakoub I, Kottke R, O’Gorman Tuura R, Ramantani G. Diffusion tensor imaging discriminates focal cortical dysplasia from normal brain parenchyma and differentiates between focal cortical dysplasia types. Insights Imaging 2023; 14:36. [PMID: 36826756 PMCID: PMC9958211 DOI: 10.1186/s13244-023-01368-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 12/29/2022] [Indexed: 02/25/2023] Open
Abstract
OBJECTIVES Although diffusion tensor imaging (DTI) may facilitate the identification of cytoarchitectural changes associated with focal cortical dysplasia (FCD), the predominant aetiology of paediatric structural epilepsy, its potential has thus far remained unexplored in this population. Here, we investigated whether DTI indices can differentiate FCD from contralateral brain parenchyma (CBP) and whether clinical features affect these indices. METHODS In this single-centre, retrospective study, we considered children and adolescents with FCD-associated epilepsy who underwent brain magnetic resonance (MRI), including DTI. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, and radial diffusivity, were calculated in both FCD and CBP. The DTI indices best discriminating between FCD and CBP were subsequently used to assess the link between DTI and selected clinical and lesion-related parameters. RESULTS We enrolled 32 patients (20 male; median age at MRI 4 years), including 15 with histologically confirmed FCD. FA values were lower (p = 0.03), whereas MD values were higher in FCD than in CBP (p = 0.04). The difference in FA values between FCD and CBP was more pronounced for a positive vs. negative history of status epilepticus (p = 0.004). Among histologically confirmed cases, the difference in FA values between FCD and CBP was more pronounced for type IIb versus type I FCD (p = 0.03). CONCLUSIONS FA and MD discriminate between FCD and CBP, while FA differentiates between FCD types. Status epilepticus increases differences in FA, potentially reflecting changes induced in the brain. Our findings support the potential of DTI to serve as a non-invasive biomarker to characterise FCD in the paediatric population.
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Affiliation(s)
- Antonio Giulio Gennari
- Department of Neuropediatrics, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032, Zurich, Switzerland. .,MR-Research Centre, University Children's Hospital Zurich, Zurich, Switzerland.
| | - Dorottya Cserpan
- grid.412341.10000 0001 0726 4330Department of Neuropediatrics, University Children’s Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland
| | - Ilona Stefanos-Yakoub
- grid.412341.10000 0001 0726 4330Department of Neuropediatrics, University Children’s Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland
| | - Raimund Kottke
- grid.412341.10000 0001 0726 4330Department of Diagnostic Imaging, University Children’s Hospital Zurich, Zurich, Switzerland
| | - Ruth O’Gorman Tuura
- grid.412341.10000 0001 0726 4330MR-Research Centre, University Children’s Hospital Zurich, Zurich, Switzerland ,grid.7400.30000 0004 1937 0650University of Zurich, Zurich, Switzerland ,grid.412341.10000 0001 0726 4330Children’s Research Centre, University Children’s Hospital Zurich, Zurich, Switzerland
| | - Georgia Ramantani
- grid.412341.10000 0001 0726 4330Department of Neuropediatrics, University Children’s Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland ,grid.7400.30000 0004 1937 0650University of Zurich, Zurich, Switzerland ,grid.412341.10000 0001 0726 4330Children’s Research Centre, University Children’s Hospital Zurich, Zurich, Switzerland
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Srivastava A, Kumar K, Banerjee J, Tripathi M, Dubey V, Sharma D, Yadav N, Sharma MC, Lalwani S, Doddamani R, Chandra PS, Dixit AB. Transcriptomic profiling of high- and low-spiking regions reveals novel epileptogenic mechanisms in focal cortical dysplasia type II patients. Mol Brain 2021; 14:120. [PMID: 34301297 PMCID: PMC8305866 DOI: 10.1186/s13041-021-00832-4] [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: 03/21/2021] [Accepted: 07/14/2021] [Indexed: 11/15/2022] Open
Abstract
Focal cortical dysplasia (FCD) is a malformation of the cerebral cortex with poorly-defined epileptogenic zones (EZs), and poor surgical outcome in FCD is associated with inaccurate localization of the EZ. Hence, identifying novel epileptogenic markers to aid in the localization of EZ in patients with FCD is very much needed. High-throughput gene expression studies of FCD samples have the potential to uncover molecular changes underlying the epileptogenic process and identify novel markers for delineating the EZ. For this purpose, we, for the first time performed RNA sequencing of surgically resected paired tissue samples obtained from electrocorticographically graded high (MAX) and low spiking (MIN) regions of FCD type II patients and autopsy controls. We identified significant changes in the MAX samples of the FCD type II patients when compared to non-epileptic controls, but not in the case of MIN samples. We found significant enrichment for myelination, oligodendrocyte development and differentiation, neuronal and axon ensheathment, phospholipid metabolism, cell adhesion and cytoskeleton, semaphorins, and ion channels in the MAX region. Through the integration of both MAX vs non-epileptic control and MAX vs MIN RNA sequencing (RNA Seq) data, PLP1, PLLP, UGT8, KLK6, SOX10, MOG, MAG, MOBP, ANLN, ERMN, SPP1, CLDN11, TNC, GPR37, SLC12A2, ABCA2, ABCA8, ASPA, P2RX7, CERS2, MAP4K4, TF, CTGF, Semaphorins, Opalin, FGFs, CALB2, and TNC were identified as potential key regulators of multiple pathways related to FCD type II pathology. We have identified novel epileptogenic marker elements that may contribute to epileptogenicity in patients with FCD and could be possible markers for the localization of EZ.
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Affiliation(s)
| | - Krishan Kumar
- Dr B R Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, 110007, India
| | | | | | - Vivek Dubey
- Department of Biophysics, AIIMS, New Delhi, India
| | - Devina Sharma
- Department of Neurosurgery, AIIMS, New Delhi, 110029, India
| | - Nitin Yadav
- Dr B R Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, 110007, India
| | - M C Sharma
- Department of Pathology, AIIMS, New Delhi, India
| | - Sanjeev Lalwani
- Department of Forensic Medicine and Toxicology, AIIMS, New Delhi, India
| | | | - P Sarat Chandra
- Department of Neurosurgery, AIIMS, New Delhi, 110029, India.
| | - Aparna Banerjee Dixit
- Dr B R Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, 110007, India.
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Lee M, Kim EJ, Woo DC, Shim WH, Yum MS. In vivo MRI Successfully Reveals the Malformation of Cortical Development in Infant Rats. Front Neurosci 2020; 14:510. [PMID: 32508585 PMCID: PMC7251149 DOI: 10.3389/fnins.2020.00510] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/24/2020] [Indexed: 01/02/2023] Open
Abstract
Objective: Malformations of cortical development (MCDs) are major causes of intractable epilepsies. To characterize the early neuroimaging findings of MCDs, we tried to identify the MRI features consistent with pathological findings in an infant rat MCD model, prenatally exposed to methylazoxymethanol (MAM), by using newly developed MRI techniques. Methods: At gestational day 15, two doses of MAM (15 mg/kg intraperitoneally) or normal saline were injected into pregnant rats. The offspring underwent in vivo MRI, including glutamate chemical exchange saturation transfer (GluCEST), 1H-MR spectroscopy, and diffusion tensor imaging, at postnatal day (P) 15 using a 7T small-animal imaging system. Another set of prenatally MAM-exposed rats were sacrificed for histological staining. Results: At P15, the retrosplenial cortex (RSC) of rats with MCDs showed decreased neuronal nuclei, parvalbumin, and reelin expressions. Moreover, dendritic arborization of pyramidal cells in the RSC significantly decreased in infant rats with MCDs. In vivo MRI showed significantly decreased GluCEST (%) in the RSC of rats with MCDs (p = 0.000) and a significant correlation between GluCEST (%) and RSC thickness (r = 0.685, p = 0.003). The rats with MCDs showed reduced glutamate (p = 0.002), N-acetylaspartate (p = 0.002), and macromolecule and lipid levels (p = 0.027) and significantly reduced fractional anisotropy values in the RSC. Conclusion: In vivo MRI revealed reduced neuronal population and dendritic arborization in the RSC of infant rats with MCDs during the early postnatal period. These pathological changes of the cortex could serve as clinical imaging biomarkers of MCDs in infants.
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Affiliation(s)
- Minyoung Lee
- Department of Pediatrics, Asan Medical Center, Asan Medical Institute of Convergence Science and Technology, University of Ulsan College of Medicine, Seoul, South Korea.,Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea
| | - Eun-Jin Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea
| | - Dong-Cheol Woo
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea
| | - Woo-Hyun Shim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea.,Department of Radiology, Asan Medical Center Children's Hospital, University of Ulsan College of Medicine, Ulsan, South Korea
| | - Mi-Sun Yum
- Department of Pediatrics, Asan Medical Center, Asan Medical Institute of Convergence Science and Technology, University of Ulsan College of Medicine, Seoul, South Korea.,Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea
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Iffland PH, Crino PB. Focal Cortical Dysplasia: Gene Mutations, Cell Signaling, and Therapeutic Implications. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2017; 12:547-571. [PMID: 28135561 DOI: 10.1146/annurev-pathol-052016-100138] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Focal cortical dysplasias (FCDs) are malformations of cortical development (MCDs) that are highly associated with medication-resistant epilepsy and are the most common cause of neocortical epilepsy in children. FCDs are a heterogeneous group of developmental disorders caused by germline or somatic mutations that occur in genes regulating the PI3K/Akt/mTOR pathway-a key pathway in neuronal growth and migration. Accordingly, FCDs are characterized by abnormal cortical lamination, cell morphology (e.g., cytomegaly), and cellular polarity. In some FCD subtypes, balloon cells express proteins typically seen in neuroglial progenitor cells. Because recurrent intractable seizures are a common feature of FCDs, epileptogenic electrophysiological properties are also observed in addition to local inflammation. Here, we will summarize the current literature regarding FCDs, addressing the current classification system, histopathology, molecular genetics, electrophysiology, and transcriptome and cell signaling changes.
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Affiliation(s)
- Philip H Iffland
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania 19140;
| | - Peter B Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland 21201;
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Nakagawa JM, Donkels C, Fauser S, Schulze-Bonhage A, Prinz M, Zentner J, Haas CA. Characterization of focal cortical dysplasia with balloon cells by layer-specific markers: Evidence for differential vulnerability of interneurons. Epilepsia 2017; 58:635-645. [PMID: 28206669 DOI: 10.1111/epi.13690] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/27/2016] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Focal cortical dysplasia (FCD) is a major cause of pharmacoresistant focal epilepsy. Little is known about the pathomechanisms underlying the characteristic cytoarchitectural abnormalities associated with FCD. In the present study, a broad panel of markers identifying layer-specific neuron subpopulations was applied to characterize dyslamination and structural alterations in FCD with balloon cells (FCD 2b). METHODS Pan-neuronal neuronal nuclei (NeuN) and layer-specific protein expression (Reelin, Calbindin, Calretinin, SMI32 (nonphosphorylated neurofilament H), Parvalbumin, transducin-like enhancer protein 4 (TLE4), and Vimentin) was studied by immunohistochemistry on paraffin sections of FCD2b cases (n = 22) and was compared to two control groups with (n = 7) or without epilepsy (n = 4 postmortem cases). Total and layer-specific neuron densities were systematically quantified by cell counting considering age at surgery and brain region. RESULTS We show that in FCD2b total neuron densities across all six cortical layers were not significantly different from controls. In addition, we present evidence that a basic laminar arrangement of layer-specific neuron subtypes was preserved despite the severe disturbance of cortical structure. SMI32-positive pyramidal neurons showed no significant difference in total numbers, but a reduction in layers III and V. The densities of supragranular Calbindin- and Calretinin-positive interneurons in layers II and III were not different from controls, whereas Parvalbumin-expressing interneurons, primarily located in layer IV, were significantly reduced in numbers when compared to control cases without epilepsy. In layer VI, the density of TLE4-positive projection neurons was significantly increased. Altogether, these data show that changes in cellular composition mainly affect deep cortical layers in FCD2b. SIGNIFICANCE The application of a broad panel of markers defining layer-specific neuronal subpopulations revealed that in FCD2b neuronal diversity and a basic laminar arrangement are maintained despite the severe disturbance of cytoarchitecture. Moreover, it showed that Parvalbumin-positive, inhibitory interneurons are highly vulnerable in contrast to other interneuron subtypes, possibly related to the epileptic condition.
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Affiliation(s)
- Julia M Nakagawa
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center-University of Freiburg, Freiburg, Germany.,Department of Neurosurgery, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Catharina Donkels
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Andreas Schulze-Bonhage
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Epilepsy Center, Medical Center-University of Freiburg, Freiburg, Germany.,BrainLinks-BrainTools, Cluster of Excellence, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS, Center for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Josef Zentner
- Department of Neurosurgery, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Carola A Haas
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BrainLinks-BrainTools, Cluster of Excellence, University of Freiburg, Freiburg, Germany
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8
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Scholl T, Mühlebner A, Ricken G, Gruber V, Fabing A, Samueli S, Gröppel G, Dorfer C, Czech T, Hainfellner JA, Prabowo AS, Reinten RJ, Hoogendijk L, Anink JJ, Aronica E, Feucht M. Impaired oligodendroglial turnover is associated with myelin pathology in focal cortical dysplasia and tuberous sclerosis complex. Brain Pathol 2017; 27:770-780. [PMID: 27750396 PMCID: PMC5697648 DOI: 10.1111/bpa.12452] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 10/06/2016] [Indexed: 12/19/2022] Open
Abstract
Conventional antiepileptic drugs suppress the excessive firing of neurons during seizures. In drug-resistant patients, treatment failure indicates an alternative important epileptogenic trigger. Two epilepsy-associated pathologies show myelin deficiencies in seizure-related brain regions: Focal Cortical Dysplasia IIB (FCD) and cortical tubers in Tuberous Sclerosis Complex (TSC). Studies uncovering white matter-pathology mechanisms are therefore urgently needed to gain more insight into epileptogenesis, the propensity to maintain seizures, and their associated comorbidities such as cognitive defects. We analyzed epilepsy surgery specimens of FCD IIB (n = 22), TSC (n = 8), and other malformations of cortical development MCD (n = 12), and compared them to autopsy and biopsy cases (n = 15). The entire lesional pathology was assessed using digital immunohistochemistry, immunofluorescence and western blotting for oligodendroglial lineage, myelin and mTOR markers, and findings were correlated to clinical parameters. White matter pathology with depleted myelin and oligodendroglia were found in 50% of FCD IIB and 62% of TSC cases. Other MCDs had either a normal content or even showed reactive oligodendrolial hyperplasia. Furthermore, myelin deficiency was associated with increased mTOR expression and the lower amount of oligodendroglia was linked with their precursor cells (PDGFRa). The relative duration of epilepsy (normalized to age) also correlated positively to mTOR activation and negatively to myelination. Decreased content of oligodendroglia and missing precursor cells indicated insufficient oligodendroglial development, probably mediated by mTOR, which may ultimately lead to severe myelin loss. In terms of disease management, an early and targeted treatment could restore normal myelin development and, therefore, alter seizure threshold and improve cognitive outcome.
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Affiliation(s)
- Theresa Scholl
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Angelika Mühlebner
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Gerda Ricken
- Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - Victoria Gruber
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria.,Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - Anna Fabing
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria.,Institute of Neurology, Medical University of Vienna, Vienna, Austria
| | - Sharon Samueli
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Gudrun Gröppel
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Christian Dorfer
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | - Thomas Czech
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | | | - Avanita S Prabowo
- Department of (Neuro) Pathology, Academic Medical Centre, Amsterdam, The Netherlands
| | - Roy J Reinten
- Department of (Neuro) Pathology, Academic Medical Centre, Amsterdam, The Netherlands
| | - Lisette Hoogendijk
- Department of (Neuro) Pathology, Academic Medical Centre, Amsterdam, The Netherlands
| | - Jasper J Anink
- Department of (Neuro) Pathology, Academic Medical Centre, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro) Pathology, Academic Medical Centre, Amsterdam, The Netherlands.,Swammerdam Institute for Life Sciences, Centre for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
| | - Martha Feucht
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
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