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Lorio S, Sedlacik J, So PW, Parkes HG, Gunny R, Löbel U, Li YF, Ogunbiyi O, Mistry T, Dixon E, Adler S, Cross JH, Baldeweg T, Jacques TS, Shmueli K, Carmichael DW. Quantitative MRI susceptibility mapping reveals cortical signatures of changes in iron, calcium and zinc in malformations of cortical development in children with drug-resistant epilepsy. Neuroimage 2021; 238:118102. [PMID: 34058334 PMCID: PMC8350142 DOI: 10.1016/j.neuroimage.2021.118102] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE Malformations of cortical development (MCD), including focal cortical dysplasia (FCD), are the most common cause of drug-resistant focal epilepsy in children. Histopathological lesion characterisation demonstrates abnormal cell types and lamination, alterations in myelin (typically co-localised with iron), and sometimes calcification. Quantitative susceptibility mapping (QSM) is an emerging MRI technique that measures tissue magnetic susceptibility (χ) reflecting it's mineral composition. We used QSM to investigate abnormal tissue composition in a group of children with focal epilepsy with comparison to effective transverse relaxation rate (R2*) and Synchrotron radiation X-ray fluorescence (SRXRF) elemental maps. Our primary hypothesis was that reductions in χ would be found in FCD lesions, resulting from alterations in their iron and calcium content. We also evaluated deep grey matter nuclei for changes in χ with age. METHODS QSM and R2* maps were calculated for 40 paediatric patients with suspected MCD (18 histologically confirmed) and 17 age-matched controls. Patients' sub-groups were defined based on concordant electro-clinical or histopathology data. Quantitative investigation of QSM and R2* was performed within lesions, using a surface-based approach with comparison to homologous regions, and within deep brain regions using a voxel-based approach with regional values modelled with age and epilepsy as covariates. Synchrotron radiation X-ray fluorescence (SRXRF) was performed on brain tissue resected from 4 patients to map changes in iron, calcium and zinc and relate them to MRI parameters. RESULTS Compared to fluid-attenuated inversion recovery (FLAIR) or T1-weighted imaging, QSM improved lesion conspicuity in 5% of patients. In patients with well-localised lesions, quantitative profiling demonstrated decreased χ, but not R2*, across cortical depth with respect to the homologous regions. Contra-lateral homologous regions additionally exhibited increased χ at 2-3 mm cortical depth that was absent in lesions. The iron decrease measured by the SRXRF in FCDIIb lesions was in agreement with myelin reduction observed by Luxol Fast Blue histochemical staining. SRXRF analysis in two FCDIIb tissue samples showed increased zinc and calcium in one patient, and decreased iron in the brain region exhibiting low χ and high R2* in both patients. QSM revealed expected age-related changes in the striatum nuclei, substantia nigra, sub-thalamic and red nucleus. CONCLUSION QSM non-invasively revealed cortical/sub-cortical tissue alterations in MCD lesions and in particular that χ changes in FCDIIb lesions were consistent with reduced iron, co-localised with low myelin and increased calcium and zinc content. These findings suggest that measurements of cortical χ could be used to characterise tissue properties non-invasively in epilepsy lesions.
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Affiliation(s)
- Sara Lorio
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, UK; Wellcome EPSRC Centre for Medical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, London SE1 7EH, UK
| | - Jan Sedlacik
- Biomedical Engineering Department, School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK; Center for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Po-Wah So
- Department of Neuroimaging, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
| | - Harold G Parkes
- Department of Neuroimaging, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK
| | - Roxana Gunny
- Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Ulrike Löbel
- Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Yao-Feng Li
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, University College London and Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK; Pathology Department, Tri-Service General Hospital and National Defence Medical Centre, Taipei, Taiwan, ROC
| | - Olumide Ogunbiyi
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, University College London and Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Talisa Mistry
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, University College London and Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Emma Dixon
- MRI Group, Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Sophie Adler
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - J Helen Cross
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Torsten Baldeweg
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Thomas S Jacques
- Developmental Biology and Cancer Programme, UCL Great Ormond Street Institute of Child Health, University College London and Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Karin Shmueli
- MRI Group, Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - David W Carmichael
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London, UK; Wellcome EPSRC Centre for Medical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, London SE1 7EH, UK.
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Aggarwal M, Li X, Gröhn O, Sierra A. Nuclei-specific deposits of iron and calcium in the rat thalamus after status epilepticus revealed with quantitative susceptibility mapping (QSM). J Magn Reson Imaging 2018; 47:554-564. [PMID: 28580758 PMCID: PMC5839879 DOI: 10.1002/jmri.25777] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 05/15/2017] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To investigate pathological changes in the rat brain after pilocarpine-induced status epilepticus using quantitative susceptibility mapping (QSM). MATERIALS AND METHODS 3D multiecho gradient-echo (GRE) data were acquired from ex vivo brains of pilocarpine-injected and age-matched control rats at 11.7T. Maps of R2* and quantitative susceptibility were calculated from the acquired 3D GRE magnitude and phase data, respectively. QSM and R2* maps were compared with Perls' (iron) and Alizarin-red-S (calcium) stainings in the same brains to investigate the pathophysiological basis of susceptibility contrast. RESULTS Bilaterally symmetric lesions were detected in reproducible thalamic regions of pilocarpine-treated rats, characterized by hyperintensity in R2* maps. In comparison, quantitative susceptibility maps demonstrated heterogeneous contrast within the lesions, with distinct hyperintense (paramagnetic) and hypointense (diamagnetic) areas. Comparison with histological assessment revealed localized deposits of iron- and calcium-positive granules in thalamic nuclei corresponding to paramagnetic and diamagnetic areas delineated in the susceptibility maps, respectively. Pronounced differences were observed in the lesions between background-corrected phase images and reconstructed susceptibility maps, indicating unreliable differentiation of iron and calcium deposits in phase maps. Multiple linear regression showed a significant association between susceptibility values and measured optical densities (ODs) of iron and calcium in the lesions (R2 = 0.42, P < 0.001), with a positive dependence on OD of iron and negative dependence on OD of calcium. CONCLUSION QSM can detect and differentiate pathological iron and calcium deposits with high sensitivity and improved spatial accuracy compared to R2* or GRE phase images, rendering it a promising technique for diagnosing thalamic lesions after status epilepticus. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:554-564.
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Affiliation(s)
- Manisha Aggarwal
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Xu Li
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- F. M. Kirby Research Center, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Olli Gröhn
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Alejandra Sierra
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
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Hobson BA, Sisó S, Rowland DJ, Harvey DJ, Bruun DA, Garbow JR, Lein PJ. From the Cover: MagneticResonance Imaging Reveals Progressive Brain Injury in Rats Acutely Intoxicated With Diisopropylfluorophosphate. Toxicol Sci 2017; 157:342-353. [PMID: 28329842 PMCID: PMC5458789 DOI: 10.1093/toxsci/kfx049] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Acute intoxication with organophosphates (OPs) can trigger seizures that progress to status epilepticus, and survivors often exhibit chronic neuropathology, cognitive impairment, affective disorders, and/or electroencephalographic abnormalities. Understanding how acute injury transitions to persistent neurological sequelae is critical to developing medical countermeasures for mitigating damage following OP-induced seizures. Here, we used in vivo magnetic resonance imaging (MRI) to monitor the spatiotemporal patterns of neuropathology for 1 month after acute intoxication with diisopropylfluorophosphate (DFP). Adult male Sprague Dawley rats administered pyridostigmine bromide (0.1 mg/kg, im) 30 min prior to successive administration of DFP (4 mg/kg, sc), atropine sulfate (2 mg/kg, im), and 2-pralidoxime (25 mg/kg, im) exhibited moderate-to-severe seizure behavior. T2-weighted and diffusion-weighted MR imaging prior to DFP exposure and at 3, 7, 14, 21, or 28 days postexposure revealed prominent lesions, tissue atrophy, and ventricular enlargement in discrete brain regions. Lesions varied in intensity and/or extent over time, with the overall magnitude of injury strongly influenced by seizure severity. Importantly, lesions detected by MRI correlated spatially and temporally with histological evidence of brain pathology. Analysis of histogram parameters extracted from frequency distributions of regional apparent diffusion coefficient (ADC) values identified the standard deviation and 90th percentile of the ADC as robust metrics for quantifying persistent and progressive neuropathological changes. The interanimal and interregional variations observed in lesion severity and progression, coupled with potential reinjury following spontaneous recurrent seizures, underscore the advantages of using in vivo imaging to longitudinally monitor neuropathology and, ultimately, therapeutic response, following acute OP intoxication.
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Affiliation(s)
- Brad A. Hobson
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, California 95616
| | - Sílvia Sisó
- Translational Biology in the Department of Research, BioMarin Pharmaceuticals Inc, Novato, California 94949
| | - Douglas J. Rowland
- Department of Biomedical Engineering and the Center for Molecular and Genomic Imaging College of Engineering
| | - Danielle J. Harvey
- Department of Public Health Sciences School of Medicine, University of California-Davis, Davis, California 95616
| | - Donald A. Bruun
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, California 95616
| | - Joel R. Garbow
- Biomedical Magnetic Resonance Laboratory, Mallinckrodt Institute of Radiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri 63110
| | - Pamela J. Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, California 95616
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Lehto LJ, Sierra A, Corum CA, Zhang J, Idiyatullin D, Pitkänen A, Garwood M, Gröhn O. Detection of calcifications in vivo and ex vivo after brain injury in rat using SWIFT. Neuroimage 2012; 61:761-72. [PMID: 22425671 DOI: 10.1016/j.neuroimage.2012.03.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 01/31/2012] [Accepted: 03/01/2012] [Indexed: 01/14/2023] Open
Abstract
Calcifications represent one component of pathology in many brain diseases. With MRI, they are most often detected by exploiting negative contrast in magnitude images. Calcifications are more diamagnetic than tissue, leading to a magnetic field disturbance that can be seen in phase MR images. Most phase imaging studies use gradient recalled echo based pulse sequences. Here, the phase component of SWIFT, a virtually zero acquisition delay sequence, was used to detect calcifications ex vivo and in vivo in rat models of status epilepticus and traumatic brain injury. Calcifications were detected in phase and imaginary SWIFT images based on their dipole like magnetic field disturbances. In magnitude SWIFT images, calcifications were distinguished as hypointense and hyperintense. Hypointense calcifications showed large crystallized granules with few surrounding inflammatory cells, while hyperintense calcifications contained small granules with the presence of more inflammatory cells. The size of the calcifications in SWIFT magnitude images correlated with that in Alizarin stained histological sections. Our data indicate that SWIFT is likely to better preserve signal in the proximity of a calcification or other field perturber in comparison to gradient echo due to its short acquisition delay and broad excitation bandwidth. Furthermore, a quantitative description for the phase contrast near dipole magnetic field inhomogeneities for the SWIFT pulse sequence is given. In vivo detection of calcifications provides a tool to probe the progression of pathology in neurodegenerative diseases. In particular, it appears to provide a surrogate marker for inflammatory cells around the calcifications after brain injury.
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Affiliation(s)
- Lauri Juhani Lehto
- Department of Neurobiology, Biomedical Imaging Unit, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
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Lado WE, Persinger MA. Spatial Memory Deficits and Their Correlations with Clusters of Shrunken Neuronal Soma in the Cortices and Limbic System Following a “Mild’’ Mechanical Impact to the Dorsal Skull in Female Rats. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/jbbs.2012.23038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Fleming JL, Persinger MA, Koren SA. Magnetic Pulses Elevate Nociceptive Thresholds: Comparisons with Opiate Receptor Compounds in Normal and Seizure-Induced Brain-Damaged Rats. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/15368379409030699] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Bureau YRJ, Persinger MA. Decreased Incidence of Limbic Motor Seizures Following Twenty Pairings of Subclinical Lithium-Pilocarpine Injections and a Complex “Burst-Firing” Magnetic Field. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/15368379509028464] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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McKay BE, Persinger MA. Normal spatial and contextual learning for ketamine-treated rats in the pilocarpine epilepsy model. Pharmacol Biochem Behav 2004; 78:111-9. [PMID: 15159140 DOI: 10.1016/j.pbb.2004.02.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2003] [Revised: 12/05/2003] [Accepted: 02/27/2004] [Indexed: 11/18/2022]
Abstract
Cognitive impairments frequently accompany epileptic disorders. Here, we examine two neuroprotective agents, the noncompetitive NMDA antagonist ketamine and the dopaminergic antagonist acepromazine, for their efficacy in attenuating cognitive impairments in the lithium-pilocarpine (LI-PILO) model of rat limbic epilepsy. Declarative-like cognitive behaviors were assessed in a Morris water maze task that consisted successively of spatial and nonspatial (cued platform) training. Whereas the ketamine-treated (Ket) LI-PILO rats performed equally in all respects to nonseized control rats for the spatial and nonspatial components of the water maze task, the acepromazine-treated (Ace) LI-PILO rats failed to demonstrate learning in either the hidden or cued platform variants of the task and did not demonstrate any place learning in the platform-removed probe trials. We further assessed nondeclarative (associative) cognitive behaviors with a standard contextual fear-conditioning protocol. LI-PILO rats treated with acepromazine failed to learn the Pavlovian relationship; Ket LI-PILO rats performed equivalently to nonseized controls. Cumulatively, these data suggest robust cognitive sparing for LI-PILO rats with pharmacological NMDA receptor antagonism following induction of status epilepticus (SE). This cognitive sparing occurs despite earlier findings that the mean amount of total brain damage with LI-PILO is equivalent for Ket and Ace rats.
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Affiliation(s)
- B E McKay
- Behavioral Neuroscience Laboratory, Laurentian University, Sudbury, Ontario, Canada P3E 2C6.
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Kubová H, Druga R, Haugvicová R, Suchomelová L, Pitkanen A. Dynamic changes of status epilepticus-induced neuronal degeneration in the mediodorsal nucleus of the thalamus during postnatal development of the rat. Epilepsia 2002; 43 Suppl 5:54-60. [PMID: 12121296 DOI: 10.1046/j.1528-1157.43.s.5.36.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE Status epilepticus (SE) was previously found to induce damage in the mediodorsal nucleus of the thalamus (MD) in both adult and immature rats. This study was designed to describe age-related changes of SE-induced neuronal degeneration in this part of the brain. METHODS SE was induced by LiCl/pilocarpine in five age groups of rats (P12-P25). Distribution of degenerating neurons was studied at various time intervals from 4 h up to 1 week using Fluoro Jade B (FJB) staining. For P12 and P25 rats, an interval of 3 months was added. RESULTS Damaged neurons were found in all age groups during a 1-week period after SE. Patterns of neuronal degeneration, however, changed in an age-related manner. In animals at P12 and P15, FJB-labeled neurons were located in the central and lateral segment of the MD. In the P18 group, degenerating neurons occurred in all three segments of the MD, with a prevalence in central and lateral subdivisions. In contrast, in P21 and P25 rats, FJB-labeled neurons were predominantly located in the central and medial segments. Degenerating neurons were still present 3 months after SE in the medial segment in P25 animals, whereas no labeled neurons were detected in the P12 group at this time. CONCLUSIONS Our data demonstrate that the pattern of neuronal degeneration in MD is mainly related to age at SE onset. In addition to damage occurring during the acute phase of SE, a population of degenerating neurons was detected in P25 animals during the chronic period 3 months after SE.
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Affiliation(s)
- H Kubová
- Institute of Physiology, Academy of Sciences of the Czech Republic, Videnská 1083, Prague 4, CZ-142 20, Czech Republic.
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Dubé C, Boyet S, Marescaux C, Nehlig A. Relationship between neuronal loss and interictal glucose metabolism during the chronic phase of the lithium-pilocarpine model of epilepsy in the immature and adult rat. Exp Neurol 2001; 167:227-41. [PMID: 11161611 DOI: 10.1006/exnr.2000.7561] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The lithium-pilocarpine (Li-Pilo) model of epilepsy reproduces most of the features of human temporal lobe epilepsy. After having studied the metabolic changes occurring during the silent phase, in the present study, we explored the relationship between interictal metabolic changes and neuronal loss during the chronic phase following status epilepticus (SE) induced by Li-Pilo in 10-day-old (P10), 21-day-old (P21), and adult rats. Rats were observed and their EEG was recorded to detect the occurrence of spontaneous recurrent seizures (SRS). Local cerebral glucose utilization was measured during the interictal period of the chronic phase, between 2 and 7 months after SE, by the [(14)C]2-deoxyglucose method in rats subjected to SE at P10, P21, or as adults. Neuronal damage was assessed by cell counting on adjacent cresyl violet stained sections. When SE was induced at P10, rats did not become epileptic, did not develop lesions and cerebral glucose utilization was in the normal range 7 months later. When SE was induced in adult rats, they all became epileptic after a mean duration of 25 days and developed lesions in the forebrain limbic areas, which were hypometabolic during the interictal period of the chronic phase, 2 months after SE. When SE was induced in P21 rats, 24% developed SRS, and in 43% seizures could be triggered (TS) by handling, after a mean delay of 74 days in both cases. The remaining 33% did not become epileptic (NS). The three groups of P21 rats developed quite comparable lesions mainly in the hilus of the dentate gyrus, lateral thalamus, and entorhinal cortex; at 6 months after SE, the forebrain was hypometabolic in NS and TS rats while it was normo- to slightly hypermetabolic in SRS rats. These data show that interictal metabolic changes are age-dependent. Moreover, there is no obvious correlation, in this model, between interictal hypometabolism and neuronal loss, as reported previously in human temporal lobe epilepsy.
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Affiliation(s)
- C Dubé
- INSERM U398, Université Louis Pasteur, Strasbourg, France
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Peredery O, Persinger MA, Parker G, Mastrosov L. Temporal changes in neuronal dropout following inductions of lithium/pilocarpine seizures in the rat. Brain Res 2000; 881:9-17. [PMID: 11033088 DOI: 10.1016/s0006-8993(00)02730-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Estimates of neuronal dropout for approximately 100 structures as defined by Paxinos-Watson were completed for brains of male Wistar albino rats between 1 and 50 days after status epilepticus was evoked by a single systemic injection of lithium and pilocarpine. Sample estimates of neuronal loss were strongly correlated with direct measures of cell density. The most extensive immediate damage occurred within the substantia nigra reticulata, CA1 field of the hippocampus, the piriform cortex and the reuniens and paratenial nuclei of the thalamus. Neuronal dropout continued in many other structures over a 50-day period. Structures that showed the greatest 2-deoxyglucose (2-DG) uptake during discrete seizures and waxing and waning seizures within the early stages of status epilepticus but the least 2-DG uptake at the time of late continuous spiking and fast spiking with pauses [Neuroscience 64 (1995) 1057, 1075] exhibited the most neuronal dropout. Relationships between the delay of injection of acepromazine (which facilitated survival) and the amount of damage suggested that the source of the process that results in permanent brain damage may originate within the region of the piriform cortices and its subcortices.
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Affiliation(s)
- O Peredery
- Neuroscience Laboratory, Departments of Psychology and Biology, Laurentian University, Ontario, P3E 2C6, Sudbury, Canada
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Kubová H, Druga R, Haugvicová R, Skutová M, Mares P. Changes in NADPH-diaphorase positivity induced by status epilepticus in allocortical structures of the immature rat brain. Brain Res Bull 1999; 48:39-47. [PMID: 10210166 DOI: 10.1016/s0361-9230(98)00143-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The distribution and time course of changes of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) positivity were studied in immature rats (12 and 25 days old) surviving motor status epilepticus (SE) induced by a high dose of pilocarpine. Motor SE characterized by continuous convulsions was interrupted after 2 h by an injection of clonazepam (0.5 mg/kg or 1 mg/kg in 12- and 25-day-old rats, respectively) in order to reduce mortality. Correlation between electroencephalographic and behavioral seizure activity was confirmed using animals with electrodes implanted bilaterally in the hippocampus and sensorimotor cortex. Brains were examined 2, 6, 13, and 21 days after motor SE using NADPH-diaphorase histochemistry. Two types of changes were found in both age groups: (a) decrease of NADPH-d positivity occurred in both neuropil and cell bodies in piriform, periamygdalar, and entorhinal cortices; and (b) NADPH-d positivity was induced in the cell bodies in the hippocampal fields CA1/2, CA3, and dentate gyrus. These changes were more intense in animals surviving SE at postnatal day 25 than in younger age group, and they peaked 2 days after SE. The changes observed after SE disappeared quickly in 12-day-old rat pups, where only moderate changes could be observed in piriform, periamygdalar, and entorhinal cortices 6 days after SE, whereas the changes in the histochemical positivity persisted in older animals even 21 days after SE.
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Affiliation(s)
- H Kubová
- Institute of Physiology, Academy of Sciences of the Czech Republic, Videnská.
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Persinger MA, Peredery O, Desjardins D, Eastman A. Ventricular dilation over several weeks following induction of excitotoxic (systemic lithium/pilocarpine) lesions: potential role of damage to the substantia nigra reticulata. Int J Neurosci 1998; 94:63-74. [PMID: 9622800 DOI: 10.3109/00207459808986439] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Time-dependent atrophy of cerebral space and enlargement of the lateral ventricles were noted in healthy rats 1 to 100 days after the induction of seizures by a single systemic injection of lithium and pilocarpine. The rate of atrophy was most strongly correlated (0.90) with the log (base 10) of the time in days. Most of the degeneration had occurred within about 20 to 30 days after the seizure-induced brain trauma. Concomitant reduction in the area of the substantia nigra reticulata was the most powerful predictor of ventricular enlargement at the level of the caudate-putamen.
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Affiliation(s)
- M A Persinger
- Neuroscience Laboratory, Laurentian University, Sudbury, Ontario, Canada
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Cook LL, Persinger MA. Demands during maze. learning in limbic epileptic rats: selective damage in the thalamus? Percept Mot Skills 1996; 83:323-9. [PMID: 8873209 DOI: 10.2466/pms.1996.83.1.323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A qualitatively evident enhancement of chromolytic neurons within the lateral posterior thalamus of rats in which limbic seizures had been induced by lithium and pilocarpine and who were later trained for spatial memory was assessed quantitatively. The significant increase in the numbers of chromolytic neurons and the decrease in the numbers of normal neurons for these rats compared to the reference brains suggested these morphological changes were recent. The hypothesis that excessive stimulation of the lateral posterior nucleus by daily training in a radial maze may have facilitated the necrosis was supported by the inverse relationship between a linear combination of the numbers of normal neurons and oligodendroglia and the rate of learning during the earlier but not the later sessions. An implication for iatrogenic effects from rehabilitation of humans following brain injury was suggested.
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Affiliation(s)
- L L Cook
- Behavioral Neuroscience Laboratory, Laurentian University, Sudbury, Ontario, Canada
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Persinger MA, Bureau YR, Peredery O. Dissociation between conditioned taste aversion and radial maze learning following seizure-induced multifocal brain damage: quantitative tests of serial vs. parallel circuit models of memory. Physiol Behav 1994; 56:225-35. [PMID: 7938231 DOI: 10.1016/0031-9384(94)90188-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Multivariate analyses between conditioned taste aversion (CTA) and radial maze acquisition (RMA) scores and percentages of neuronal dropout within thalamic and telencephalic structures were completed for rats in which overt seizures had been evoked following a single systemic injection of lithium/pilocarpine. Despite multifocal damage, only the amount of damage within the hippocampus (CA1) and the basolateral amygdala was most strongly associated with attenuated CTA, whereas damage within the mediodorsal thalamus was primarily associated with RMA. There was no significant correlation between CTA or RMA. Multiple regression analyses for specific Paxinos and Watson structures and their traditional aggregates supported more precise delineation of neuronal substrates of learning/memory and a multimodal (parallel) model for these processes.
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Affiliation(s)
- M A Persinger
- Behavioral Neuroscience Program, Laurentian University, Sudbury, Ontario, Canada
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Bureau YR, Peredery O, Persinger MA. Concordance of quantitative damage within the diencephalon and telencephalon following systemic pilocarpine (380 mg/kg) or lithium (3 mEq/kg)/pilocarpine (30 mg/kg) induced seizures. Brain Res 1994; 648:265-9. [PMID: 7922540 DOI: 10.1016/0006-8993(94)91126-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We tested the hypothesis that a single systemic injection of 380 mg/kg of the muscarinic agonist pilocarpine would produce more diffuse and severe seizure-induced brain damage than a single injection of lithium (3 mEq/kg) followed 4 h later by < 1/10 the dosage of pilocarpine. The hypothesis was not supported; the pattern of quantitative brain damage 50-60 days after the seizures were elicited by either treatment was comparable within the limits of measurement error. Within the diencephalon and subcortical telencephalon the same structures were either damaged in a similar quantitative manner or were spared. Only five of the 119 damaged structures exhibited statistically significant treatment differences at P < 0.01. The results are compatible with the explanation that lithium may enhance the excitotoxic effects of subsequent muscarinic stimulation.
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Affiliation(s)
- Y R Bureau
- Behavioral Neuroscience Program, Laurentian University, Sudbury, Ont., Canada
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Kostakos M, Persinger MA, Peredery O. Deficits in working but not reference memory in adult rats in which limbic seizures had been induced before weaning: implications for early brain injuries. Neurosci Lett 1993; 158:209-12. [PMID: 8233097 DOI: 10.1016/0304-3940(93)90266-n] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Male adult rats that displayed limbic seizures between postnatal days 18 and 21 after a single s.c. injection of Li followed 4 h later by a muscarinic agent were trained in a radial arm maze; they were compared with rats that had received the Li-pilocarpine (but had not displayed overt seizures) and to nonhandled controls. Only the rats that had displayed the (preweaned) seizures displayed significant impairment for working memory but not for reference memory. Light microscopy demonstrated histological evidence of earlier damage only within select thalamic structures that are directly associated with the amygdaloid-hippocampal complex. The results are compatible with the hypothesis that early seizures during the time of CA1 hippocampal maturation can produce long-term changes in the efficacy of short-term memory.
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Affiliation(s)
- M Kostakos
- Behavioral Neuroscience Laboratory, Laurentian University, Sudbury, Ont., Canada
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Persinger MA, Bureau YR, Kostakos M, Peredery O, Falter H. Behaviors of rats with insidious, multifocal brain damage induced by seizures following single peripheral injections of lithium and pilocarpine. Physiol Behav 1993; 53:849-66. [PMID: 8511200 DOI: 10.1016/0031-9384(93)90261-d] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Several domains of behavior were measured in rats (n = 465) 10 days to 100 days after induction of limbic seizures by a single subcutaneous injection of lithium and pilocarpine. These rats displayed enhanced intragroup aggression but normal muricide; gustatory neophobia and conditioned taste aversion were virtually eliminated. Severe working and reference memory deficits were evident within the radial arm maze. Both state-dependent memory and possible situation-dependent precipitation of spontaneous seizures were suggested. The behavioral changes were considered commensurate with the multifocal pattern of thalamic, hippocampal/amygdaloid, and limbic cortical damage.
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Affiliation(s)
- M A Persinger
- Behavioral Neuroscience Program, Laurentian University, Sudbury, Ontario, Canada
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Bureau YR, Persinger MA. Transient blocking of persistent gnawing by haloperidol in rats with seizure-induced multifocal brain damage. Life Sci 1993; 52:869-76. [PMID: 8445981 DOI: 10.1016/0024-3205(93)90516-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Frequent but phasic gnawing of objects is displayed by rats in which severe damage within: 1) the substantia nigra reticulata, 2) all of the amygdaloid nuclei except the central group and 3) multiple thalamic nuclei, was induced by lithium/pilocarpine-induced seizures. Multiple lesions were produced by these rats upon their own tails as well as upon the tails of their cage mates. These behaviors were considered predictable sequela of the disinhibition of compacta dopamine upon orofacial mechanisms that are modulated by the corpus striatum. In a manner similar to tail pinch-induced eating, the usually quick onset of spontaneous gnawing upon food chunks in a test setting was delayed transiently by appropriate dosages of haloperidol.
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Affiliation(s)
- Y R Bureau
- Behavioral Neuroscience Laboratory, Laurentian University, Sudbury, Ontario, Canada
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