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Bernardino PN, Hobson BA, Huddleston SL, Andrew PM, MacMahon JA, Saito NH, Porter VA, Bruun DA, Harvey DJ, Garbow JR, Gelli A, Chaudhari AJ, Lein PJ. Time- and region-dependent blood-brain barrier impairment in a rat model of organophosphate-induced status epilepticus. Neurobiol Dis 2023; 187:106316. [PMID: 37797902 PMCID: PMC11000668 DOI: 10.1016/j.nbd.2023.106316] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 09/26/2023] [Accepted: 10/02/2023] [Indexed: 10/07/2023] Open
Abstract
Acute organophosphate (OP) intoxication can trigger seizures that progress to status epilepticus (SE), and survivors often develop chronic morbidities, including spontaneous recurrent seizures (SRS). The pathogenic mechanisms underlying OP-induced SRS are unknown, but increased BBB permeability is hypothesized to be involved. Previous studies reported BBB leakage following OP-induced SE, but key information regarding time and regional distribution of BBB impairment during the epileptogenic period is missing. To address this data gap, we characterized the spatiotemporal progression of BBB impairment during the first week post-exposure in a rat model of diisopropylfluorophosphate-induced SE, using MRI and albumin immunohistochemistry. Increased BBB permeability, which was detected at 6 h and persisted up to 7 d post-exposure, was most severe and persistent in the piriform cortex and amygdala, moderate but persistent in the thalamus, and less severe and transient in the hippocampus and somatosensory cortex. The extent of BBB leakage was positively correlated with behavioral seizure severity, with the strongest association identified in the piriform cortex and amygdala. These findings provide evidence of the duration, magnitude and spatial breakdown of the BBB during the epileptogenic period following OP-induced SE and support BBB regulation as a viable therapeutic target for preventing SRS following acute OP intoxication.
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Affiliation(s)
- Pedro N Bernardino
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA.
| | - Brad A Hobson
- Center for Molecular and Genomic Imaging, University of California, Davis, Davis, CA 95616, USA.
| | - Sydney L Huddleston
- Center for Molecular and Genomic Imaging, University of California, Davis, Davis, CA 95616, USA.
| | - Peter M Andrew
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA.
| | - Jeremy A MacMahon
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA.
| | - Naomi H Saito
- Department of Public Health Sciences, University of California, Davis, School of Medicine, Davis, CA 95616, USA.
| | - Valerie A Porter
- Department of Biomedical Engineering, University of California, Davis, College of Engineering, Davis, CA 95616, USA.
| | - Donald A Bruun
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA.
| | - Danielle J Harvey
- Department of Public Health Sciences, University of California, Davis, School of Medicine, Davis, CA 95616, USA.
| | - Joel R Garbow
- Biomedical Magnetic Resonance Center, Mallinckrodt Institute of Radiology, School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA.
| | - Angie Gelli
- Department of Pharmacology, University of California, Davis, School of Medicine, Davis, CA 95616, USA.
| | - Abhijit J Chaudhari
- Center for Molecular and Genomic Imaging, University of California, Davis, Davis, CA 95616, USA; Department of Radiology, University of California, Davis, School of Medicine, Sacramento, CA 95817, USA.
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA.
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Cai M, Lin W. The Function of NF-Kappa B During Epilepsy, a Potential Therapeutic Target. Front Neurosci 2022; 16:851394. [PMID: 35360161 PMCID: PMC8961383 DOI: 10.3389/fnins.2022.851394] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 02/22/2022] [Indexed: 01/04/2023] Open
Abstract
The transcriptional regulator nuclear factor kappa B (NF-κB) modulates cellular biological activity by binding to promoter regions in the nucleus and transcribing various protein-coding genes. The NF-κB pathway plays a major role in the expressing genes related to inflammation, including chemokines, interleukins, and tumor necrosis factor. It also transcribes genes that can promote neuronal survival or apoptosis. Epilepsy is one of the most common brain disorders and it not only causes death worldwide but also affects the day-to-day life of affected individuals. While epilepsy has diverse treatment options, there remain patients who are not sensitive to the existing treatment methods. Recent studies have implicated the critical role of NF-κB in epilepsy. It is upregulated in neurons, glial cells, and endothelial cells, due to neuronal loss, glial cell proliferation, blood-brain barrier dysfunction, and hippocampal sclerosis through the glutamate and γ-aminobutyric acid imbalance, ion concentration changes, and other mechanisms. In this review, we summarize the functional changes caused by the upregulation of NF-κB in the central nervous system during different periods after seizures. This review is the first to deconvolute the complicated functions of NF-κB, and speculate that the regulation of NF-κB can be a safe and effective treatment strategy for epilepsy.
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Kaiser L, Holzgreve A, Quach S, Ingrisch M, Unterrainer M, Dekorsy FJ, Lindner S, Ruf V, Brosch-Lenz J, Delker A, Böning G, Suchorska B, Niyazi M, Wetzel CH, Riemenschneider MJ, Stöcklein S, Brendel M, Rupprecht R, Thon N, von Baumgarten L, Tonn JC, Bartenstein P, Ziegler S, Albert NL. Differential Spatial Distribution of TSPO or Amino Acid PET Signal and MRI Contrast Enhancement in Gliomas. Cancers (Basel) 2021; 14:cancers14010053. [PMID: 35008218 PMCID: PMC8750092 DOI: 10.3390/cancers14010053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/10/2021] [Accepted: 12/14/2021] [Indexed: 01/14/2023] Open
Abstract
Simple Summary Radiotracers targeting the translocator protein (TSPO) have recently gained substantial interest, since TSPO is overexpressed in malignant gliomas, where it correlates inversely with patient’s survival. The high-affinity TSPO PET ligand [18F]GE180 was found to depict tumor areas with a remarkably high contrast and has been shown to provide non-invasive information on histological tumor grades. Yet, its significance was questioned with the argument, that the high contrast may solely arise from nonspecific accumulation in tissue supplied by leaky vessels. This study aimed to address this question by providing a detailed evaluation of spatial associations between TSPO and amino acid PET with relative contrast enhancement in T1-weighted MRI. The results show that [18F]GE180 contrast does not reflect a disrupted blood–brain barrier (BBB) only and that multi-modal imaging generates complementary information, which may better depict spatial heterogeneity of tumor biology and may be used to individualize the therapy for each patient. Abstract In this study, dual PET and contrast enhanced MRI were combined to investigate their correlation per voxel in patients at initial diagnosis with suspected glioblastoma. Correlation with contrast enhancement (CE) as an indicator of BBB leakage was further used to evaluate whether PET signal is likely caused by BBB disruption alone, or rather attributable to specific binding after BBB passage. PET images with [18F]GE180 and the amino acid [18F]FET were acquired and normalized to healthy background (tumor-to-background ratio, TBR). Contrast enhanced images were normalized voxel by voxel with the pre-contrast T1-weighted MRI to generate relative CE values (rCE). Voxel-wise analysis revealed a high PET signal even within the sub-volumes without detectable CE. No to moderate correlation of rCE with TBR voxel-values and a small overlap as well as a larger distance of the hotspots delineated in rCE and TBR-PET images were detected. In contrast, voxel-wise correlation between both PET modalities was strong for most patients and hotspots showed a moderate overlap and distance. The high PET signal in tumor sub-volumes without CE observed in voxel-wise analysis as well as the discordant hotspots emphasize the specificity of the PET signals and the relevance of combined differential information from dual PET and MRI images.
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Affiliation(s)
- Lena Kaiser
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
- Correspondence:
| | - Adrien Holzgreve
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Stefanie Quach
- Department of Neurosurgery, University Hospital, LMU Munich, 81377 Munich, Germany; (S.Q.); (N.T.); (L.v.B.); (J.-C.T.)
| | - Michael Ingrisch
- Department of Radiology, University Hospital, LMU Munich, 81377 Munich, Germany; (M.I.); (S.S.)
| | - Marcus Unterrainer
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
- Department of Radiology, University Hospital, LMU Munich, 81377 Munich, Germany; (M.I.); (S.S.)
| | - Franziska J. Dekorsy
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Simon Lindner
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Viktoria Ruf
- Center for Neuropathology and Prion Research, LMU Munich, 81377 Munich, Germany; (V.R.); (R.R.)
| | - Julia Brosch-Lenz
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Astrid Delker
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Guido Böning
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | | | - Maximilian Niyazi
- Department of Radiation Oncology, University Hospital, LMU Munich, 81377 Munich, Germany;
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Christian H. Wetzel
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany;
| | | | - Sophia Stöcklein
- Department of Radiology, University Hospital, LMU Munich, 81377 Munich, Germany; (M.I.); (S.S.)
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany;
| | - Niklas Thon
- Department of Neurosurgery, University Hospital, LMU Munich, 81377 Munich, Germany; (S.Q.); (N.T.); (L.v.B.); (J.-C.T.)
| | - Louisa von Baumgarten
- Department of Neurosurgery, University Hospital, LMU Munich, 81377 Munich, Germany; (S.Q.); (N.T.); (L.v.B.); (J.-C.T.)
| | - Jörg-Christian Tonn
- Department of Neurosurgery, University Hospital, LMU Munich, 81377 Munich, Germany; (S.Q.); (N.T.); (L.v.B.); (J.-C.T.)
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Sibylle Ziegler
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
| | - Nathalie L. Albert
- Department of Nuclear Medicine, University Hospital, LMU Munich, 81377 Munich, Germany; (A.H.); (M.U.); (F.J.D.); (S.L.); (J.B.-L.); (A.D.); (G.B.); (M.B.); (P.B.); (S.Z.); (N.L.A.)
- German Cancer Consortium (DKTK), Partner Site Munich, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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Bouilleret V, Dedeurwaerdere S. What value can TSPO PET bring for epilepsy treatment? Eur J Nucl Med Mol Imaging 2021; 49:221-233. [PMID: 34120191 DOI: 10.1007/s00259-021-05449-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/03/2021] [Indexed: 12/13/2022]
Abstract
Epilepsy is one of the most common neurological disorders and affects both the young and adult populations. The question we asked for this review was how positron emission tomography (PET) imaging with translocator protein (TSPO) radioligands can help inform the epilepsy clinic and the development of future treatments targeting neuroinflammatory processes.Even though the first TSPO PET scans in epilepsy patients were performed over 20 years ago, this imaging modality has not seen wide adoption in the clinic. There is vast scientific evidence from preclinical studies in rodent models of temporal lobe epilepsy which have shown increased levels of TSPO corresponding to neuroinflammatory processes in the brain. These increases peaked sub-acutely (1-2 weeks) after the epileptogenic insult (e.g. status epilepticus) and remained chronically increased, albeit at lower levels. In addition, these studies have shown a correlation between TSPO levels and seizure outcome, pharmacoresistance and behavioural morbidities. Histological assessment points to a complex interplay between different cellular components such as microglial activation, astrogliosis and cell death changing dynamically over time.In epilepsy patients, a highly sensitive biomarker of neuroinflammation would provide value for the optimization of surgical assessment (particularly for extratemporal lobe epilepsy) and support the clinical development path of anti-inflammatory treatments. Clinical studies have shown a systematic increase in asymmetry indices of TSPO PET binding. However, region-based analysis typically does not yield statistical differences and changes are often not restricted to the epileptogenic zone, limiting the ability of this imaging modality to localise pathology for surgery. In this manuscript, we discuss the biological underpinnings of these findings and review for which applications in epilepsy TSPO PET could bring added value.
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Affiliation(s)
- Viviane Bouilleret
- Unité de Neurophysiologie et d'Epileptologie (UNCE), Université Paris-Saclay APHP, 78, Rue du Général Leclerc, 94275, Le Kremlin Bicêtre, France.
- CEA, CNRS, Inserm, BioMaps, Université Paris-Saclay, Orsay, France.
| | - Stefanie Dedeurwaerdere
- Neurosciences Therapeutic Area, Early Solutions, UCB Pharma, Braine-l'Alleud, Belgium
- Experimental Laboratory of Haematology, University of Antwerp, Wilrijk, Belgium
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Bandopadhyay R, Singh T, Ghoneim MM, Alshehri S, Angelopoulou E, Paudel YN, Piperi C, Ahmad J, Alhakamy NA, Alfaleh MA, Mishra A. Recent Developments in Diagnosis of Epilepsy: Scope of MicroRNA and Technological Advancements. BIOLOGY 2021; 10:1097. [PMID: 34827090 PMCID: PMC8615191 DOI: 10.3390/biology10111097] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/21/2021] [Accepted: 10/21/2021] [Indexed: 12/18/2022]
Abstract
Epilepsy is one of the most common neurological disorders, characterized by recurrent seizures, resulting from abnormally synchronized episodic neuronal discharges. Around 70 million people worldwide are suffering from epilepsy. The available antiepileptic medications are capable of controlling seizures in around 60-70% of patients, while the rest remain refractory. Poor seizure control is often associated with neuro-psychiatric comorbidities, mainly including memory impairment, depression, psychosis, neurodegeneration, motor impairment, neuroendocrine dysfunction, etc., resulting in poor prognosis. Effective treatment relies on early and correct detection of epileptic foci. Although there are currently a few well-established diagnostic techniques for epilepsy, they lack accuracy and cannot be applied to patients who are unsupportive or harbor metallic implants. Since a single test result from one of these techniques does not provide complete information about the epileptic foci, it is necessary to develop novel diagnostic tools. Herein, we provide a comprehensive overview of the current diagnostic tools of epilepsy, including electroencephalography (EEG) as well as structural and functional neuroimaging. We further discuss recent trends and advances in the diagnosis of epilepsy that will enable more effective diagnosis and clinical management of patients.
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Affiliation(s)
- Ritam Bandopadhyay
- Department of Pharmacology, School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India;
| | - Tanveer Singh
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, USA;
| | - Mohammed M. Ghoneim
- Department of Pharmacy Practice, College of Pharmacy, AlMaarefa University, Ad Diriyah 13713, Saudi Arabia;
| | - Sultan Alshehri
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Efthalia Angelopoulou
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (E.A.); (C.P.)
| | - Yam Nath Paudel
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Subang Jaya 47500, Selangor, Malaysia;
| | - Christina Piperi
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (E.A.); (C.P.)
| | - Javed Ahmad
- Department of Pharmaceutics, College of Pharmacy, Najran University, Najran 11001, Saudi Arabia;
| | - Nabil A. Alhakamy
- Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (N.A.A.); (M.A.A.)
| | - Mohamed A. Alfaleh
- Department of Pharmaceutics, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (N.A.A.); (M.A.A.)
- Vaccines and Immunotherapy Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Awanish Mishra
- Department of Pharmacology, School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411, Punjab, India;
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER)—Guwahati, Changsari, Guwahati 781101, Assam, India
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de Curtis M, Rossetti AO, Verde DV, van Vliet EA, Ekdahl CT. Brain pathology in focal status epilepticus: evidence from experimental models. Neurosci Biobehav Rev 2021; 131:834-846. [PMID: 34517036 DOI: 10.1016/j.neubiorev.2021.09.011] [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: 04/20/2021] [Revised: 09/02/2021] [Accepted: 09/05/2021] [Indexed: 12/01/2022]
Abstract
Status Epilepticus (SE) is often a neurological emergency characterized by abnormally sustained, longer than habitual seizures. The new ILAE classification reports that SE "…can have long-term consequences including neuronal death, neuronal injury…depending on the type and duration of seizures". While it is accepted that generalized convulsive SE exerts detrimental effects on the brain, it is not clear if other forms of SE, such as focal non-convulsive SE, leads to brain pathology and contributes to long-term deficits in patients. With the available clinical and experimental data, it is hard to discriminate the specific action of the underlying SE etiologies from that exerted by epileptiform activity. This information is highly relevant in the clinic for better treatment stratification, which may include both medical and surgical intervention for seizure control. Here we review experimental studies of focal SE, with an emphasis on focal non-convulsive SE. We present a repertoire of brain pathologies observed in the most commonly used animal models and attempt to establish a link between experimental findings and human condition(s). The extensive literature on focal SE animal models suggest that the current approaches have significant limitations in terms of translatability of the findings to the clinic. We highlight the need for a more stringent description of SE features and brain pathology in experimental studies in animal models, to improve the accuracy in predicting clinical translation.
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Affiliation(s)
- Marco de Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto NeurologicoCarlo Besta, Milano, Italy.
| | - Andrea O Rossetti
- Department of Clinical Neuroscience, University Hospital (CHUV) and University of Lausanne, Lausanne, Switzerland
| | - Diogo Vila Verde
- Epilepsy Unit, Fondazione IRCCS Istituto NeurologicoCarlo Besta, Milano, Italy
| | - Erwin A van Vliet
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, P.O. Box 94246, 1090 GE, Amsterdam, the Netherlands; Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Meibergdreef 9, Amsterdam, the Netherlands
| | - Christine T Ekdahl
- Division of Clinical Neurophysiology, Lund University, Sweden; Lund Epilepsy Center, Dept Clinical Sciences, Lund University, Sweden
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Löscher W, Klein P. New approaches for developing multi-targeted drug combinations for disease modification of complex brain disorders. Does epilepsy prevention become a realistic goal? Pharmacol Ther 2021; 229:107934. [PMID: 34216705 DOI: 10.1016/j.pharmthera.2021.107934] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/16/2021] [Accepted: 06/16/2021] [Indexed: 12/14/2022]
Abstract
Over decades, the prevailing standard in drug discovery was the concept of designing highly selective compounds that act on individual drug targets. However, more recently, multi-target and combinatorial drug therapies have become an important treatment modality in complex diseases, including neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The development of such network-based approaches is facilitated by the significant advance in our understanding of the pathophysiological processes in these and other complex brain diseases and the adoption of modern computational approaches in drug discovery and repurposing. However, although drug combination therapy has become an effective means for the symptomatic treatment of many complex diseases, the holy grail of identifying clinically effective disease-modifying treatments for neurodegenerative and other brain diseases remains elusive. Thus, despite extensive research, there remains an urgent need for novel treatments that will modify the progression of the disease or prevent its development in patients at risk. Here we discuss recent approaches with a focus on multi-targeted drug combinations for prevention or modification of epilepsy. Over the last ~10 years, several novel promising multi-targeted therapeutic approaches have been identified in animal models. We envision that synergistic combinations of repurposed drugs as presented in this review will be demonstrated to prevent epilepsy in patients at risk within the next 5-10 years.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
| | - Pavel Klein
- Mid-Atlantic Epilepsy and Sleep Center, Bethesda, MD, USA
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Bertoglio D, Amhaoul H, Goossens J, Ali I, Jonckers E, Bijnens T, Siano M, Wyffels L, Verhaeghe J, Van der Linden A, Staelens S, Dedeurwaerdere S. TSPO PET upregulation predicts epileptic phenotype at disease onset independently from chronic TSPO expression in a rat model of temporal lobe epilepsy. Neuroimage Clin 2021; 31:102701. [PMID: 34090124 PMCID: PMC8182303 DOI: 10.1016/j.nicl.2021.102701] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/10/2021] [Accepted: 05/14/2021] [Indexed: 12/12/2022]
Abstract
Neuroinflammation is a key component of epileptogenesis, the process leading to acquired epilepsy. In recent years, with the development of non-invasive in vivo positron emission tomography (PET) imaging of translocator protein 18 kDa (TSPO), a marker of neuroinflammation, it has become possible to perform longitudinal studies to characterize neuroinflammation at different disease stages in animal models of epileptogenesis. This study aimed to utilize the prognostic capability of TSPO PET imaging at disease onset (2 weeks post-SE) to categorize epileptic rats with distinct seizure burden based on TSPO levels at disease onset and investigate their association to TSPO expression at the chronic epilepsy stage. Controls (n = 14) and kainic acid-induced status epilepticus (KASE) rats (n = 41) were scanned non-invasively with [18F]PBR111 PET imaging measuring TSPO expression. Animals were monitored using video-electroencephalography (vEEG) up to chronic disease (12 weeks post-SE), at which TSPO levels ([3H]PK11195) as well as other post-mortem abnormalities (namely synaptic density ([3H]UCB-J), neuronal loss (NeuN), and neurodegeneration (FjC)) were investigated. By applying multivariate analysis, TSPO PET imaging at disease onset identified three KASE groups with significantly different spontaneous recurrent seizures (SRS) burden (defined as rare SRS, sporadic SRS, and frequent SRS) (p = 0.003). Interestingly, TSPO levels were significantly different when comparing the three KASE groups (p < 0.0001), with the frequent SRS group characterized only by a limited focal TSPO increase at disease onset. On the contrary, TSPO measured during chronic epilepsy was found to be the highest in the frequent SRS group and correlated with seizure burden (r = 0.826, p < 0.0001). Importantly, early and chronic TSPO levels did not correlate (r = -0.05). Finally, significant pathological changes in neuronal loss, synaptic density, and neurodegeneration were found not only when compared to control animals (p < 0.01), but also between the three KASE rat categories in the hippocampus (p < 0.05). Early and chronic TSPO upregulation following epileptogenic insult appear to be driven by two superimposed dynamic processes. The former is associated with epileptogenesis as measured at disease onset, while the latter is related to seizure frequency as quantified during chronic epilepsy.
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Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium; Department of Translational Neurosciences, University of Antwerp, Belgium.
| | - Halima Amhaoul
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | - Joery Goossens
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | - Idrish Ali
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | | | - Tom Bijnens
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | - Matteo Siano
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | - Leonie Wyffels
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium; Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium
| | | | - Steven Staelens
- Department of Translational Neurosciences, University of Antwerp, Belgium
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Identification of clinically relevant biomarkers of epileptogenesis - a strategic roadmap. Nat Rev Neurol 2021; 17:231-242. [PMID: 33594276 DOI: 10.1038/s41582-021-00461-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2021] [Indexed: 01/31/2023]
Abstract
Onset of many forms of epilepsy occurs after an initial epileptogenic insult or as a result of an identified genetic defect. Given that the precipitating insult is known, these epilepsies are, in principle, amenable to secondary prevention. However, development of preventive treatments is difficult because only a subset of individuals will develop epilepsy and we cannot currently predict which individuals are at the highest risk. Biomarkers that enable identification of these individuals would facilitate clinical trials of potential anti-epileptogenic treatments, but no such prognostic biomarkers currently exist. Several putative molecular, imaging, electroencephalographic and behavioural biomarkers of epileptogenesis have been identified, but clinical translation has been hampered by fragmented and poorly coordinated efforts, issues with inter-model reproducibility, study design and statistical approaches, and difficulties with validation in patients. These challenges demand a strategic roadmap to facilitate the identification, characterization and clinical validation of biomarkers for epileptogenesis. In this Review, we summarize the state of the art with respect to biomarker research in epileptogenesis and propose a five-phase roadmap, adapted from those developed for cancer and Alzheimer disease, that provides a conceptual structure for biomarker research.
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10
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Narayanaswami V, Tong J, Schifani C, Bloomfield PM, Dahl K, Vasdev N. Preclinical Evaluation of TSPO and MAO-B PET Radiotracers in an LPS Model of Neuroinflammation. PET Clin 2021; 16:233-247. [PMID: 33648665 DOI: 10.1016/j.cpet.2020.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Discovery of novel PET radiotracers targeting neuroinflammation (microglia and astrocytes) is actively pursued. Employing a lipopolysaccharide (LPS) rat model, this longitudinal study evaluated the translocator protein 18-kDa radiotracer [18F]FEPPA (primarily microglia) and monoamine oxidase B radiotracers [11C]L-deprenyl and [11C]SL25.1188 (astrocytes preferred). Increased [18F]FEPPA binding peaked at 1 week in LPS-injected striatum whereas increased lazabemide-sensitive [11C]L-deprenyl binding developed later. No increase in radiotracer uptake was observed for [11C]SL25.1188. The unilateral intrastriatal LPS rat model may serve as a useful tool for benchmarking PET tracers targeted toward distinct phases of neuroinflammatory reactions involving both microglia and astrocytes.
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Affiliation(s)
- Vidya Narayanaswami
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Room 270, Toronto, Ontario M5T 1R8, Canada
| | - Junchao Tong
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Room 339, Toronto, Ontario M5T 1R8, Canada
| | - Christin Schifani
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Room 270, Toronto, Ontario M5T 1R8, Canada
| | - Peter M Bloomfield
- Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Room B26A, Toronto, Ontario M5T 1R8, Canada
| | - Kenneth Dahl
- Azrieli Centre for Neuro-Radiochemistry, Brain Health Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Room B02, Toronto, Ontario M5T 1R8, Canada
| | - Neil Vasdev
- Department of Psychiatry, Brain Health Imaging Centre, Azrieli Centre for Neuro-Radiochemistry, Centre for Addiction and Mental Health, University of Toronto, 250 College Street, Room PET G2, Toronto, Ontario M5T 1R8, Canada.
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11
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Zhang L, Hu K, Shao T, Hou L, Zhang S, Ye W, Josephson L, Meyer JH, Zhang MR, Vasdev N, Wang J, Xu H, Wang L, Liang SH. Recent developments on PET radiotracers for TSPO and their applications in neuroimaging. Acta Pharm Sin B 2021; 11:373-393. [PMID: 33643818 PMCID: PMC7893127 DOI: 10.1016/j.apsb.2020.08.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/15/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022] Open
Abstract
The 18 kDa translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor, is predominately localized to the outer mitochondrial membrane in steroidogenic cells. Brain TSPO expression is relatively low under physiological conditions, but is upregulated in response to glial cell activation. As the primary index of neuroinflammation, TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), multiple sclerosis (MS), major depressive disorder (MDD) and obsessive compulsive disorder (OCD). In this context, numerous TSPO-targeted positron emission tomography (PET) tracers have been developed. Among them, several radioligands have advanced to clinical research studies. In this review, we will overview the recent development of TSPO PET tracers, focusing on the radioligand design, radioisotope labeling, pharmacokinetics, and PET imaging evaluation. Additionally, we will consider current limitations, as well as translational potential for future application of TSPO radiopharmaceuticals. This review aims to not only present the challenges in current TSPO PET imaging, but to also provide a new perspective on TSPO targeted PET tracer discovery efforts. Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.
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Key Words
- AD, Alzheimer's disease
- ALS, amyotrophic lateral sclerosis
- AMPA, α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid
- ANT, adenine nucleotide transporter
- Am, molar activities
- BBB, blood‒brain barrier
- BMSC, bone marrow stromal cells
- BP, binding potential
- BPND, non-displaceable binding potential
- BcTSPO, Bacillus cereus TSPO
- CBD, corticobasal degeneration
- CNS disorders
- CNS, central nervous system
- CRAC, cholesterol recognition amino acid consensus sequence
- DLB, Lewy body dementias
- EP, epilepsy
- FTD, frontotemporal dementia
- HAB, high-affinity binding
- HD, Huntington's disease
- HSE, herpes simplex encephalitis
- IMM, inner mitochondrial membrane
- KA, kainic acid
- LAB, low-affinity binding
- LPS, lipopolysaccharide
- MAB, mixed-affinity binding
- MAO-B, monoamine oxidase B
- MCI, mild cognitive impairment
- MDD, major depressive disorder
- MMSE, mini-mental state examination
- MRI, magnetic resonance imaging
- MS, multiple sclerosis
- MSA, multiple system atrophy
- Microglial activation
- NAA/Cr, N-acetylaspartate/creatine
- Neuroinflammation
- OCD, obsessive compulsive disorder
- OMM, outer mitochondrial membrane
- P2X7R, purinergic receptor P2X7
- PAP7, RIa-associated protein
- PBR, peripheral benzodiazepine receptor
- PCA, posterior cortical atrophy
- PD, Parkinson's disease
- PDD, PD dementia
- PET, positron emission tomography
- PKA, protein kinase A
- PRAX-1, PBR-associated protein 1
- PSP, progressive supranuclear palsy
- Positron emission tomography (PET)
- PpIX, protoporphyrin IX
- QA, quinolinic acid
- RCYs, radiochemical yields
- ROS, reactive oxygen species
- RRMS, relapsing remitting multiple sclerosis
- SA, specific activity
- SAH, subarachnoid hemorrhage
- SAR, structure–activity relationship
- SCIDY, spirocyclic iodonium ylide
- SNL, selective neuronal loss
- SNR, signal to noise ratio
- SUV, standard uptake volume
- SUVR, standard uptake volume ratio
- TBAH, tetrabutyl ammonium hydroxide
- TBI, traumatic brain injury
- TLE, temporal lobe epilepsy
- TSPO
- TSPO, translocator protein
- VDAC, voltage-dependent anion channel
- VT, distribution volume
- d.c. RCYs, decay-corrected radiochemical yields
- dMCAO, distal middle cerebral artery occlusion
- fP, plasma free fraction
- n.d.c. RCYs, non-decay-corrected radiochemical yields
- p.i., post-injection
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12
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Sridharan S, Raffel J, Nandoskar A, Record C, Brooks DJ, Owen D, Sharp D, Muraro PA, Gunn R, Nicholas R. Confirmation of Specific Binding of the 18-kDa Translocator Protein (TSPO) Radioligand [ 18F]GE-180: a Blocking Study Using XBD173 in Multiple Sclerosis Normal Appearing White and Grey Matter. Mol Imaging Biol 2020; 21:935-944. [PMID: 30796709 DOI: 10.1007/s11307-019-01323-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Measurements of non-displaceable binding (VND) of positron emission tomography (PET) ligands are not often made in vivo in humans because they require ligands to displace binding to target receptors and there are few readily available, safe ones to use. A technique to measure VND for ligands for the 18-kDa translocator protein (TSPO) has recently been developed which compares the total volume of distribution (VT) before and after administration of the TSPO ligand XBD173. Here, we used XBD173 with an occupancy plot to quantify VND for two TSPO radiotracers, [18F]GE-180 and [11C]PBR28, in cohorts of people with multiple sclerosis (MS). Additionally, we compared plots of subjects carrying high (HAB) or mixed binding (MAB) affinity polymorphisms of TSPO to estimate VND without receptor blockade. PROCEDURES Twelve people with MS underwent baseline MRI and 90-min dynamic [18F]GE-180 PET or [11C]PBR28 PET (n = 6; three HAB, three MAB each). Arterial blood sampling was used to generate plasma input functions for the two-tissue compartment model. VND was calculated using two independent methods: the occupancy plot (by modelling the differences in signal post XBD173) and the polymorphism plot (by modelling the differences in signal across presence and absence of rs6971 genotypes). RESULTS Whole brain VT (mean ± standard deviation) was 0.29 ± 0.17 ml/cm3 for [18F]GE-180 and 5.01 ± 1.88 ml/cm3 for [11C]PBR28. Using the occupancy and polymorphism plots respectively, VND for [18F]GE-180 was 0.11 ml/cm3 (95 % CI = 0.02, 0.16) and 0.20 ml/cm3 (0.16, 0.34), accounting for, on average, 55 % of VT in the whole brain. For [11C]PBR28, these values were 3.81 ml/cm3 (3.02, 4.21) and 3.49 ml/cm3 (1.38, 4.27), accounting for 67 % of average whole brain VT. CONCLUSIONS Although VT for [18F]GE-180 is low, indicating low brain penetration, half the signal shown by MS subjects reflected specific TSPO binding. VT for [11C]PBR28 was higher and two thirds of the binding was non-specific. No brain ROIs were devoid of specific signal, further confirming that true reference tissue approaches are potentially problematic for estimating TSPO levels.
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Affiliation(s)
- Sujata Sridharan
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.
| | - Joel Raffel
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Ashwini Nandoskar
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Chris Record
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - David J Brooks
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.,Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Institute of Neuroscience, Newcastle upon Tyne University, Newcastle upon Tyne, UK
| | - David Owen
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - David Sharp
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Paolo A Muraro
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | | | - Richard Nicholas
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
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13
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Garner R, La Rocca M, Vespa P, Jones N, Monti MM, Toga AW, Duncan D. Imaging biomarkers of posttraumatic epileptogenesis. Epilepsia 2019; 60:2151-2162. [PMID: 31595501 PMCID: PMC6842410 DOI: 10.1111/epi.16357] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 12/14/2022]
Abstract
Traumatic brain injury (TBI) affects 2.5 million people annually within the United States alone, with over 300 000 severe injuries resulting in emergency room visits and hospital admissions. Severe TBI can result in long-term disability. Posttraumatic epilepsy (PTE) is one of the most debilitating consequences of TBI, with an estimated incidence that ranges from 2% to 50% based on severity of injury. Conducting studies of PTE poses many challenges, because many subjects with TBI never develop epilepsy, and it can be more than 10 years after TBI before seizures begin. One of the unmet needs in the study of PTE is an accurate biomarker of epileptogenesis, or a panel of biomarkers, which could provide early insights into which TBI patients are most susceptible to PTE, providing an opportunity for prophylactic anticonvulsant therapy and enabling more efficient large-scale PTE studies. Several recent reviews have provided a comprehensive overview of this subject (Neurobiol Dis, 123, 2019, 3; Neurotherapeutics, 11, 2014, 231). In this review, we describe acute and chronic imaging methods that detect biomarkers for PTE and potential mechanisms of epileptogenesis. We also describe shortcomings in current acquisition methods, analysis, and interpretation that limit ongoing investigations that may be mitigated with advancements in imaging techniques and analysis.
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Affiliation(s)
- Rachael Garner
- Laboratory of Neuro Imaging, USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States
| | - Marianna La Rocca
- Laboratory of Neuro Imaging, USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States
| | - Paul Vespa
- Division of Neurosurgery, Department of Neurology, University of California Los Angeles School of Medicine, Los Angeles, CA, United States
| | - Nigel Jones
- Van Cleef Centre for Nervous Diseases, Department of Neuroscience, Monash University, Clayton, VIC, Australia
| | - Martin M. Monti
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, United States
| | - Arthur W. Toga
- Laboratory of Neuro Imaging, USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States
| | - Dominique Duncan
- Laboratory of Neuro Imaging, USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States
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14
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Ojo ES, Ishola IO, Ben-Azu B, Afolayan OO, James AB, Ajayi AM, Umukoro S, Adeyemi OO. Ameliorative influence of Cnestis ferruginea vahl ex DC (Connaraceae) root extract on kainic acid-induced temporal lobe epilepsy in mice: Role of oxidative stress and neuroinflammation. JOURNAL OF ETHNOPHARMACOLOGY 2019; 243:112117. [PMID: 31351192 DOI: 10.1016/j.jep.2019.112117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/18/2019] [Accepted: 07/23/2019] [Indexed: 06/10/2023]
Abstract
UNLABELLED ETHNOPHARMACOLOGY RELEVANCE: the root decoction of Cnestis ferruginea Vahl ex DC (Connaraceae) is widely used in traditional African medicine for the treatment of various ailments including pain, inflammation and epilepsy. We have earlier reported anticonvulsant effect of Cnestis ferruginea root extract in mice. AIM OF THE STUDY to evaluate the effect of ethanolic root extract of Cnestis ferruginea (CF) on kainic acid (KA)-induced temporal lobe epilepsy (TLE) in mice as well as the involvement of inflammatory mediators and oxidative stress. MATERIALS AND METHODS mice were randomly divided into preventive treatment (vehicle (normal saline) or CF (400 mg/kg, p.o.) for 3 consecutive days before KA (5 mg/kg, i.p.) on days 4 and 5. In the reversal model, KA (5 mg/kg, i.p.) was administered on days 1 and 2 before vehicle or CF (400 mg/kg) administration on days 3-5. The effect of treatments on seizure severity was recorded using Racine scale. Animals were euthanized on day 5, 6 h after last KA exposure in preventive model and 1 h after CF administration in reversal model to estimate markers of oxidative stress and neuroinflammation. RESULTS exposure of mice to KA induced TLE evidenced in increased severity of seizures which was significantly reduced by the pre- and post-treatment of mice with CF. Moreso, KA-induced malondialdehyde/nitrite generation and GSH deficit in the brain were attenuated by CF treatments. KA-induced up-regulation of inflammatory transcription factors; cyclooxygenase-2 (COX-2) and nuclear facor-kappaB (NF-κB) in the CA1, CA2, CA3 and dentate gyrus (DG) regions of the hippocampus regions were attenuated by CF treatments. CONCLUSION findings from this study showed that Cnestis ferruginea root extract ameliorated KA-induced TLE through enhancement of antioxidant defense mechanism and attenuation of neuro-inflammatory transcription factors. Thus, could possibly be a potential phytotherapeutic agent in the management of temporal lobe epilepsy.
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Affiliation(s)
- Emmanuel S Ojo
- Department of Pharmacology, Therapeutics and Toxicology, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos State, Nigeria
| | - Ismail O Ishola
- Department of Pharmacology, Therapeutics and Toxicology, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos State, Nigeria
| | - Benneth Ben-Azu
- Neuropharmacology Unit, Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria; Department of Pharmacology, Faculty of Basic Medical Sciences, PAMO University of Medical Sciences, Port Harcourt, Rivers State, Nigeria
| | - Olasunmbo O Afolayan
- Department of Anatomy, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos State, Nigeria
| | - Ayorinde B James
- Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos State, Nigeria
| | - Abayomi M Ajayi
- Neuropharmacology Unit, Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Solomon Umukoro
- Neuropharmacology Unit, Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Ibadan, Oyo State, Nigeria
| | - Olufunmilayo O Adeyemi
- Department of Pharmacology, Therapeutics and Toxicology, Faculty of Basic Medical Sciences, College of Medicine, University of Lagos, Lagos State, Nigeria.
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15
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Bascuñana P, Gendron T, Sander K, Jahreis I, Polyak A, Ross TL, Bankstahl M, Arstad E, Bankstahl JP. Ex vivo characterization of neuroinflammatory and neuroreceptor changes during epileptogenesis using candidate positron emission tomography biomarkers. Epilepsia 2019; 60:2325-2333. [PMID: 31571210 DOI: 10.1111/epi.16353] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/04/2019] [Accepted: 09/04/2019] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Identification of patients at risk of developing epilepsy before the first spontaneous seizure may promote the development of preventive treatment providing opportunity to stop or slow down the disease. METHODS As development of novel radiotracers and on-site setup of existing radiotracers is highly time-consuming and expensive, we used dual-centre in vitro autoradiography as an approach to characterize the potential of innovative radiotracers in the context of epilepsy development. Using brain slices from the same group of rats, we aimed to characterise the evolution of neuroinflammation and expression of inhibitory and excitatory neuroreceptors during epileptogenesis using translational positron emission tomography (PET) tracers; 18 F-flumazenil (18 F-FMZ; GABAA receptor), 18 F-FPEB (metabotropic glutamate receptor 5; mGluR5), 18 F-flutriciclamide (translocator protein; TSPO, microglia activation) and 18 F-deprenyl (monoamine oxidase B, astroglia activation). Autoradiography images from selected time points after pilocarpine-induced status epilepticus (SE; baseline, 24 and 48 hours, 5, 10 and 15 days and 6 and 12-14 weeks after SE) were normalized to a calibration curve, co-registered to an MRI-based 2D region-of-interest atlas, and activity concentration (Bq/mm2 ) was calculated. RESULTS In epileptogenesis-associated brain regions, 18 F-FMZ and 18 F-FPEB showed an early decrease after SE. 18 F-FMZ decrease was maintained in the latent phase and further reduced in the chronic epileptic animals, while 18 F-FPEB signal recovered from day 10, reaching baseline levels in chronic epilepsy. 18 F-flutriciclamide showed an increase of activated microglia at 24 hours after SE, peaking at 5-15 days and decreasing during the chronic phase. On the other hand, 18 F-deprenyl autoradiography showed late astrogliosis, peaking in the chronic phase. SIGNIFICANCE Autoradiography revealed different evolution of the selected targets during epileptogenesis. Our results suggest an advantage of combined imaging of inter-related targets like glutamate and GABAA receptors, or microglia and astrocyte activation, in order to identify important interactions, especially when using PET imaging for the evaluation of novel treatments.
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Affiliation(s)
- Pablo Bascuñana
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Thibault Gendron
- Institute of Nuclear Medicine, University College London, London, UK.,Department of Chemistry, University College London, London, UK
| | - Kerstin Sander
- Institute of Nuclear Medicine, University College London, London, UK.,Department of Chemistry, University College London, London, UK
| | - Ina Jahreis
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany.,Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Andras Polyak
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Tobias L Ross
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Marion Bankstahl
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Institute for Laboratory Animal Science, Hannover Medical School, Hannover, Germany
| | - Erik Arstad
- Institute of Nuclear Medicine, University College London, London, UK.,Department of Chemistry, University College London, London, UK
| | - Jens P Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
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16
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Dickstein LP, Liow JS, Austermuehle A, Zoghbi S, Inati SK, Zaghloul K, Zanotti-Fregonara P, Theodore WH. Neuroinflammation in neocortical epilepsy measured by PET imaging of translocator protein. Epilepsia 2019; 60:1248-1254. [PMID: 31144767 DOI: 10.1111/epi.15967] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 04/25/2019] [Accepted: 04/25/2019] [Indexed: 02/06/2023]
Abstract
OBJECTIVES Neuroinflammation, implicated in epilepsy, can be imaged in humans with positron emission tomography (PET) ligands for translocator protein 18 kDa (TSPO). Previous studies in patients with temporal lobe epilepsy and mesial temporal sclerosis found increased [11C]PBR28 uptake ipsilateral to seizure foci. Neocortical foci present more difficult localization problems and more variable underlying pathology. METHODS We studied 11 patients with neocortical seizure foci using [11C]PBR28 or [11C] N,N-diethyl-2-(4-methoxyphenyl)-5,7-dimethylpyrazolo[1,5-a]pyrimidine-3-acetamide (DPA) 713, and 31 healthy volunteers. Seizure foci were identified with structural magnetic resonance imaging (MRI) and ictal video-electroencephalography (EEG) monitoring. Six patients had surgical resections; five had focal cortical dysplasia type 2A or B and one microdysgenesis. Brain regions were delineated using FreeSurfer and T1-weighted MRI. We measured brain radioligand uptake (standardized uptake values [SUVs]) in ipsilateral and contralateral regions, to compare calculated asymmetry indices [AIs; 200% *(ipsilateral - contralateral)/(ipsilateral + contralateral)] between epilepsy patients and controls, as well as absolute [11C]PBR28 binding as the ratio of distribution volume to free fraction (VT /fP ) in 9 patients (5 high affinity and 4 medium affinity binders) and 11 age-matched volunteers (5 high-affinity and 6 medium affinity) who had metabolite-corrected arterial input functions measured. RESULTS Nine of 11 patients had AIs exceeding control mean 95% confidence intervals in at least one region consistent with the seizure focus. Three of the nine had normal MRI. There was a nonsignificant trend for patients to have higher binding than volunteers both ipsilateral and contralateral to the focus in the group that had absolute binding measured. SIGNIFICANCE Our study demonstrates the presence of focal and distributed inflammation in neocortical epilepsy. There may be a role for TSPO PET for evaluation of patients with suspected neocortical seizure foci, particularly when other imaging modalities are unrevealing. However, a complex method, inherent variability, and increased binding in regions outside seizure foci will limit applicability.
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Affiliation(s)
- Leah P Dickstein
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Alison Austermuehle
- Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Sami Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Sara K Inati
- EEG Section, OCD, National Institute of Neurological Disorders and Stroke, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Kareem Zaghloul
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Paolo Zanotti-Fregonara
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - William H Theodore
- Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
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17
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Neuroimaging Biomarkers of Experimental Epileptogenesis and Refractory Epilepsy. Int J Mol Sci 2019; 20:ijms20010220. [PMID: 30626103 PMCID: PMC6337422 DOI: 10.3390/ijms20010220] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 12/31/2018] [Accepted: 01/03/2019] [Indexed: 11/17/2022] Open
Abstract
This article provides an overview of neuroimaging biomarkers in experimental epileptogenesis and refractory epilepsy. Neuroimaging represents a gold standard and clinically translatable technique to identify neuropathological changes in epileptogenesis and longitudinally monitor its progression after a precipitating injury. Neuroimaging studies, along with molecular studies from animal models, have greatly improved our understanding of the neuropathology of epilepsy, such as the hallmark hippocampus sclerosis. Animal models are effective for differentiating the different stages of epileptogenesis. Neuroimaging in experimental epilepsy provides unique information about anatomic, functional, and metabolic alterations linked to epileptogenesis. Recently, several in vivo biomarkers for epileptogenesis have been investigated for characterizing neuronal loss, inflammation, blood-brain barrier alterations, changes in neurotransmitter density, neurovascular coupling, cerebral blood flow and volume, network connectivity, and metabolic activity in the brain. Magnetic resonance imaging (MRI) is a sensitive method for detecting structural and functional changes in the brain, especially to identify region-specific neuronal damage patterns in epilepsy. Positron emission tomography (PET) and single-photon emission computerized tomography are helpful to elucidate key functional alterations, especially in areas of brain metabolism and molecular patterns, and can help monitor pathology of epileptic disorders. Multimodal procedures such as PET-MRI integrated systems are desired for refractory epilepsy. Validated biomarkers are warranted for early identification of people at risk for epilepsy and monitoring of the progression of medical interventions.
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18
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Imaging biomarkers of epileptogenecity after traumatic brain injury - Preclinical frontiers. Neurobiol Dis 2018; 123:75-85. [PMID: 30321600 DOI: 10.1016/j.nbd.2018.10.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/04/2018] [Accepted: 10/11/2018] [Indexed: 02/06/2023] Open
Abstract
Posttraumatic epilepsy (PTE) is a major neurodegenerative disease accounting for 20% of symptomatic epilepsy cases. A long latent phase offers a potential window for prophylactic treatment strategies to prevent epilepsy onset, provided that the patients at risk can be identified. Some promising imaging biomarker candidates for posttraumatic epileptogenesis have been identified, but more are required to provide the specificity and sensitivity for accurate prediction. Experimental models and preclinical longitudinal, multimodal imaging studies allow follow-up of complex cascade of events initiated by traumatic brain injury, as well as monitoring of treatment effects. Preclinical imaging data from the posttraumatic brain are rich in information, yet examination of their specific relevance to epilepsy is lacking. Accumulating evidence from ongoing preclinical studies in TBI support insight into processes involved in epileptogenesis, e.g. inflammation and changes in functional and structural brain-wide connectivity. These efforts are likely to produce both new biomarkers and treatment targets for PTE.
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Unterrainer M, Mahler C, Vomacka L, Lindner S, Havla J, Brendel M, Böning G, Ertl-Wagner B, Kümpfel T, Milenkovic VM, Rupprecht R, Kerschensteiner M, Bartenstein P, Albert NL. TSPO PET with [ 18F]GE-180 sensitively detects focal neuroinflammation in patients with relapsing-remitting multiple sclerosis. Eur J Nucl Med Mol Imaging 2018. [PMID: 29523925 DOI: 10.1007/s00259-018-3974-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
PURPOSE Expression of the translocator protein (TSPO) is upregulated in activated macrophages/microglia and is considered to be a marker of neuroinflammation. We investigated the novel TSPO ligand [18F]GE-180 in patients with relapsing-remitting multiple sclerosis (RRMS) to determine the feasibility of [18F]GE-180 PET imaging in RRMS patients and to assess its ability to detect active inflammatory lesions in comparison with the current gold standard, contrast-enhanced magnetic resonance imaging (MRI). METHODS Nineteen RRMS patients were prospectively included in this study. All patients underwent TSPO genotyping and were classified as high-affinity, medium-affinity or low-affinity binders (HAB/MAB/LAB). PET scans were performed after administration of 189 ± 12 MBq [18F]GE-180, and 60-90 min summation images were used for visual analysis and assessment of standardized uptake values (SUV). The frontal nonaffected cortex served as a pseudoreference region (PRR) for evaluation of SUV ratios (SUVR). PET data were correlated with MRI signal abnormalities, i.e. T2 hyperintensity or contrast enhancement (CE). When available, previous MRI data were used to follow the temporal evolution of individual lesions. RESULTS Focal lesions were identified as hot spots by visual inspection. Such lesions were detected in 17 of the 19 patients and overall 89 [18F]GE-180-positive lesions were found. TSPO genotyping revealed 11 patients with HAB status, 5 with MAB status and 3 with LAB status. There were no associations between underlying binding status (HAB, MAB and LAB) and the signal intensity in either lesions (SUVR 1.87 ± 0.43, 1.95 ± 0.48 and 1.86 ± 0.80, respectively; p = 0.280) or the PRR (SUV 0.36 ± 0.03, 0.40 ± 0.06 and 0.37 ± 0.03, respectively; p = 0.990). Of the 89 [18F]GE-180-positive lesions, 70 showed CE on MRI, while the remainder presented as T2 lesions without CE. SUVR were significantly higher in lesions with CE than in those without (2.00 ± 0.53 vs. 1.60 ± 0.15; p = 0.001). Notably, of 19 [18F]GE-180-positive lesions without CE, 8 previously showed CE, indicating that [18F]GE-180 imaging may be able to detect lesional activity that is sustained beyond the blood-brain barrier breakdown. CONCLUSION [18F]GE-180 PET can detect areas of focal macrophage/microglia activation in patients with RRMS in lesions with and without CE on MRI. Therefore, [18F]GE-180 PET imaging is a sensitive and quantitative approach to the detection of active MS lesions. It may provide information beyond contrast-enhanced MRI and is readily applicable to all patients. [18F]GE-180 PET imaging is therefore a promising new tool for the assessment of focal inflammatory activity in MS.
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Affiliation(s)
- Marcus Unterrainer
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians University Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - C Mahler
- Institute of Clinical Neuroimmunology, University Hospital, LMU Munich, Munich, Germany.,Biomedical Center (BMC), LMU Munich, Munich, Germany
| | - L Vomacka
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians University Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - S Lindner
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians University Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - J Havla
- Institute of Clinical Neuroimmunology, University Hospital, LMU Munich, Munich, Germany.,Biomedical Center (BMC), LMU Munich, Munich, Germany
| | - M Brendel
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians University Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - G Böning
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians University Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - B Ertl-Wagner
- Institute of Clinical Radiology, University Hospital, LMU Munich, Munich, Germany
| | - T Kümpfel
- Institute of Clinical Neuroimmunology, University Hospital, LMU Munich, Munich, Germany.,Biomedical Center (BMC), LMU Munich, Munich, Germany
| | - V M Milenkovic
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - R Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - M Kerschensteiner
- Institute of Clinical Neuroimmunology, University Hospital, LMU Munich, Munich, Germany.,Biomedical Center (BMC), LMU Munich, Munich, Germany.,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - P Bartenstein
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians University Munich, Marchioninistr. 15, 81377, Munich, Germany.,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Nathalie L Albert
- Department of Nuclear Medicine, University Hospital, Ludwig-Maximilians University Munich, Marchioninistr. 15, 81377, Munich, Germany. .,Munich Cluster of Systems Neurology (SyNergy), Munich, Germany.
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Brackhan M, Bascuñana P, Ross TL, Bengel FM, Bankstahl JP, Bankstahl M. [18
F]GE180 positron emission tomographic imaging indicates a potential double-hit insult in the intrahippocampal kainate mouse model of temporal lobe epilepsy. Epilepsia 2018; 59:617-626. [DOI: 10.1111/epi.14009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2018] [Indexed: 01/14/2023]
Affiliation(s)
- Mirjam Brackhan
- Department of Nuclear Medicine; Hannover Medical School; Hannover Germany
- Department of Pharmacology, Toxicology, and Pharmacy; University of Veterinary Medicine; Hannover Germany
| | - Pablo Bascuñana
- Department of Nuclear Medicine; Hannover Medical School; Hannover Germany
| | - Tobias L. Ross
- Department of Nuclear Medicine; Hannover Medical School; Hannover Germany
| | - Frank M. Bengel
- Department of Nuclear Medicine; Hannover Medical School; Hannover Germany
| | - Jens P. Bankstahl
- Department of Nuclear Medicine; Hannover Medical School; Hannover Germany
| | - Marion Bankstahl
- Department of Pharmacology, Toxicology, and Pharmacy; University of Veterinary Medicine; Hannover Germany
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Neuroimaging in animal models of epilepsy. Neuroscience 2017; 358:277-299. [DOI: 10.1016/j.neuroscience.2017.06.062] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 06/27/2017] [Accepted: 06/28/2017] [Indexed: 02/06/2023]
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