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Zhang L, Huang J, Dai L, Zhu G, Yang XL, He Z, Li YH, Yang H, Zhang CQ, Shen KF, Liang P. Expression profiles of α-synuclein in cortical lesions of patients with FCD IIb and TSC, and FCD rats. Front Neurol 2023; 14:1255097. [PMID: 38020594 PMCID: PMC10662349 DOI: 10.3389/fneur.2023.1255097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 10/06/2023] [Indexed: 12/01/2023] Open
Abstract
Background Focal cortical dysplasia (FCD) IIb and tuberous sclerosis complex (TSC) are common causes of drug-resistant epilepsy in children. However, the etiologies related to the development of FCD IIb and TSC are not fully understood. α-synuclein (α-syn) is a member of synucleins family that plays crucial roles in modulating synaptic transmission in central nervous system. Here, we explored the expression profiles and potential pathogenic functions of α-syn in cortical lesions of epileptic patients with FCD IIb and TSC. Methods Surgical specimens from epileptic patients with FCD IIb and TSC, as well as FCD rats generated by in utero X-ray-radiation were adopted in this study and studied with immunohistochemistry, immunofluorescence, western blotting, and co-immunoprecipitation etc. molecular biological techniques. Result Our results showed that α-syn expression was reduced in FCD IIb and TSC lesions. Specifically, α-syn protein was intensely expressed in dysplastic neurons (DNs) and balloon cells (BCs) in FCD IIb lesions, whereas was barely detected in DNs and giant cells (GCs) of TSC lesions. Additionally, p-α-syn, the aggregated form of α-syn, was detected in DNs, BCs, GCs, and glia-like cells of FCD IIb and TSC lesions. We previous showed that the function of N-methyl-D-aspartate receptor (NMDAR) was enhanced in FCD rats generated by X-ray-radiation. Here, we found the interaction between α-syn and NMDAR subunits NMDAR2A, NMDAR2B were augmented in cortical lesions of FCD patients and FCD rats. Conclusion These results suggested a potential role of α-syn in the pathogenesis of FCD IIb and TSC by interfering with NMDAR.
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Affiliation(s)
- Li Zhang
- Department of Neurosurgery, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Jun Huang
- Department of Neurosurgery, Epilepsy Research Center of PLA, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Lu Dai
- Chongqing Institute for Brain and Intelligence, Guang Yang Bay Laboratory, Chongqing, China
| | - Gang Zhu
- Department of Neurosurgery, Epilepsy Research Center of PLA, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Xiao-Lin Yang
- Department of Neurosurgery, Epilepsy Research Center of PLA, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Zeng He
- Department of Neurosurgery, Epilepsy Research Center of PLA, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Yu-Hong Li
- Department of Cell Biology, Basic Medical College, Army Medical University, Chongqing, China
| | - Hui Yang
- Department of Neurosurgery, Epilepsy Research Center of PLA, Xinqiao Hospital, Army Medical University, Chongqing, China
- Chongqing Institute for Brain and Intelligence, Guang Yang Bay Laboratory, Chongqing, China
| | - Chun-Qing Zhang
- Department of Neurosurgery, Epilepsy Research Center of PLA, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Kai-Feng Shen
- Department of Neurosurgery, Epilepsy Research Center of PLA, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Ping Liang
- Department of Neurosurgery, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing, China
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Ghosh C, Myers R, O'Connor C, Williams S, Liu X, Hossain M, Nemeth M, Najm IM. Cortical Dysplasia in Rats Provokes Neurovascular Alterations, GLUT1 Dysfunction, and Metabolic Disturbances That Are Sustained Post-Seizure Induction. Mol Neurobiol 2022; 59:2389-2406. [PMID: 35084654 PMCID: PMC9018620 DOI: 10.1007/s12035-021-02624-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 10/26/2021] [Indexed: 10/19/2022]
Abstract
Focal cortical dysplasia (FCD) is associated with blood-brain barrier (BBB) dysfunction in patients with difficult-to-treat epilepsy. However, the underlying cellular and molecular factors in cortical dysplasia (CD) associated with progressive neurovascular challenges during the pro-epileptic phase, post-seizure, and during epileptogenesis remain unclear. We studied the BBB function in a rat model of congenital (in utero radiation-induced, first hit) CD and longitudinally examined the cortical brain tissues at baseline and the progressive neurovascular alterations, glucose transporter-1 (GLUT1) expression, and glucose metabolic activity at 2, 15, and 30 days following a second hit using pentylenetetrazole-induced seizure. Our study revealed through immunoblotting, immunohistochemistry, and biochemical analysis that (1) altered vascular density and prolongation of BBB albumin leakages in CD rats continued through 30 days post-seizure; (2) CD brain tissues showed elevated matrix metalloproteinase-9 levels at 2 days post-seizure and microglial overactivation through 30 days post-seizure; (3) BBB tight junction protein and GLUT1 levels were decreased and neuronal monocarboxylate transporter-2 (MCT2) and mammalian target of rapamycin (mTOR) levels were increased in the CD rat brain: (4) ATPase activity is elevated and a low glucose/high lactate imbalance exists in CD rats; and (5) the mTOR pathway is activated and MCT2 levels are elevated in the presence of high lactate during glucose starvation in vitro. Together, this study suggests that BBB dysfunction, including decreased GLUT1 expression and metabolic disturbance, may contribute to epileptogenesis in this CD rat model through multiple mechanisms that could be translated to FCD therapy in medically refractory epilepsy.
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Affiliation(s)
- Chaitali Ghosh
- Cerebrovascular Research, Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA. .,Department of Biomedical Engineering and Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA.
| | - Rosemary Myers
- Cerebrovascular Research, Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Christina O'Connor
- Charles Shor Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Sherice Williams
- Cerebrovascular Research, Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Xuefeng Liu
- Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Mohammed Hossain
- Cerebrovascular Research, Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Michael Nemeth
- Charles Shor Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Imad M Najm
- Charles Shor Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
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Interneuron dysfunction in epilepsy: An experimental approach using immature brain insults to induce neuronal migration disorders. Epilepsy Res 2019; 156:106185. [DOI: 10.1016/j.eplepsyres.2019.106185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 07/13/2019] [Accepted: 08/02/2019] [Indexed: 01/16/2023]
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4
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Najm IM, Sarnat HB, Blümcke I. Review: The international consensus classification of Focal Cortical Dysplasia - a critical update 2018. Neuropathol Appl Neurobiol 2018; 44:18-31. [DOI: 10.1111/nan.12462] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/03/2018] [Indexed: 12/13/2022]
Affiliation(s)
- I. M. Najm
- Cleveland Clinic Epilepsy Centre; Cleveland OH USA
| | - H. B. Sarnat
- Faculty of Medicine; Departments of Paediatrics, Pathology (Neuropathology) and Clinical Neurosciences; University of Calgary; Calgary AB Canada
| | - I. Blümcke
- Department of Neuropathology; University Hospital; Erlangen Germany
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Kielbinski M, Gzielo K, Soltys Z. Review: Roles for astrocytes in epilepsy: insights from malformations of cortical development. Neuropathol Appl Neurobiol 2018; 42:593-606. [PMID: 27257021 DOI: 10.1111/nan.12331] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 05/25/2016] [Accepted: 06/03/2016] [Indexed: 12/25/2022]
Abstract
Malformations of cortical development (MCDs), such as cortical dysplasia and tuberous sclerosis complex, are common causes of intractable epilepsy, especially in paediatric patients. Recently, mounting evidence points to a common pathology of these disorders. Hyperactivation of mammalian target of rapamycin (mTOR) has been proposed as a central mechanism in most, if not all, MCDs. The transition from mTOR hyperactivation and cellular abnormalities to large-scale functional changes and seizure is, however, not fully understood. In this article we set out to review currently available information regarding MCD pathology, focusing on glial cells - especially astrocytes - and their interactions with the brain vascular system. A large body of evidence points to these elements as potential targets in MCD. Here, we attempt to provide a review of this evidence and propose some hypotheses regarding the possible chain of events linking primary glial dysfunction and epilepsy. We focus on extracellular matrix remodelling, blood-brain barrier leakage and failure of astrocyte-dependent removal of extracellular debris. We posit that the failure of these systems results in a chronically pro-inflammatory environment, maintaining local astrocytes in a state of gliosis, with increased susceptibility to seizures as a consequence.
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Affiliation(s)
- M Kielbinski
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Krakow, Poland
| | - K Gzielo
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Krakow, Poland
| | - Z Soltys
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Krakow, Poland
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Growth Associated Protein 43 (GAP-43) as a Novel Target for the Diagnosis, Treatment and Prevention of Epileptogenesis. Sci Rep 2017; 7:17702. [PMID: 29255203 PMCID: PMC5735087 DOI: 10.1038/s41598-017-17377-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 11/21/2017] [Indexed: 12/19/2022] Open
Abstract
We previously showed increased growth associated protein 43 (GAP-43) expression in brain samples resected from patients with cortical dysplasia (CD), which was correlated with duration of epilepsy. Here, we used a rat model of CD to examine the regulation of GAP-43 in the brain and serum over the course of epileptogenesis. Baseline GAP-43 expression was higher in CD animals compared to control non-CD rats. An acute seizure increased GAP-43 expression in both CD and control rats. However, GAP-43 expression decreased by day 15 post-seizure in control rats, which did not develop spontaneous seizures. In contrast, GAP-43 remained up-regulated in CD rats, and over 50% developed chronic epilepsy with increased GAP-43 levels in their serum. GAP-43 protein was primarily located in excitatory neurons, suggesting its functional significance in epileptogenesis. Inhibition of GAP-43 expression by shRNA significantly reduced seizure duration and severity in CD rats after acute seizures with subsequent reduction in interictal spiking. Serum GAP-43 levels were significantly higher in CD rats that developed spontaneous seizures. Together, these results suggest GAP-43 as a key factor promoting epileptogenesis, a possible therapeutic target for treatment of progressive epilepsy and a potential biomarker for epilepsy progression in CD.
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Nemes AD, O'Dwyer R, Najm IM, Ying Z, Gonzalez-Martinez J, Alexopoulos AV. Treatment with lacosamide impedes generalized seizures in a rodent model of cortical dysplasia. Epilepsia 2017; 58:1755-1761. [PMID: 28833036 DOI: 10.1111/epi.13856] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2017] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Epilepsy is a common neurologic disorder resulting in spontaneous, recurrent seizures. About 30-40% of patients are not responsive to pharmacologic therapies. This may be due to the differences between individual patients such as etiology, underlying pathophysiology, and seizure focus, and it highlights the importance of new drug discovery and testing in this field. Our goal was to determine the efficacy of lacosamide (LCM), a drug approved for the treatment of focal seizures, in a model of generalized epilepsy with cortical dysplasia (CD). We sought to compare LCM to levetiracetam (LEV), a drug that is currently used for the treatment of both partial and generalized epilepsy and to test its proficiency. METHODS Pregnant rats were irradiated to produce pups with malformed cortices in a model of CD, which will be referred to as the "first hit." Adult animals, developed normally (NL) and irradiated (XRT), were surgically implanted with electroencephalography (EEG) electrodes. Baseline EEG was recorded on all rats prior to pretreatments with either LCM, LEV, or placebo (PBO). After 30 min, all rats were injected with a subconvulsive dose of pentylenetetrazole (PTZ), a γ-aminobutyric acid receptor A (GABAA ) antagonist used to provoke generalized seizures as a "second hit." RESULTS LCM and LEV were both effective against seizures induced by PTZ. XRT rats had a higher seizure incidence with longer and more severe seizures than NL rats. Seizure duration was decreased with both LCM and LEV in all animals. In XRT rats, there was a significant reduction in acute seizure incidence and severity with both LCM and LEV after PTZ injection. SIGNIFICANCE Our results suggest that LCM could be used as a potential treatment option for generalized epilepsy with CD as the underlying pathology.
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Affiliation(s)
- Ashley D Nemes
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, U.S.A
| | - Rebecca O'Dwyer
- Department of Neurological Sciences, Rush Medical College, Chicago, Illinois, U.S.A
| | - Imad M Najm
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, U.S.A
| | - Zhong Ying
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio, U.S.A
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Nemes A, Najm IM, Gale JT, Ying Z, Johnson M, Gonzalez-Martinez J. Underlying Cortical Dysplasia as Risk Factor for Traumatic Epilepsy: An Animal Study. J Neurotrauma 2016; 33:1883-1891. [DOI: 10.1089/neu.2015.4220] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- Ashley Nemes
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio
| | - Imad M. Najm
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio
| | - John T. Gale
- Department of Neurosciences and Center for Neurological Restoration, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Zhong Ying
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio
| | - Matthew Johnson
- Department of Neurosciences and Center for Neurological Restoration, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Jorge Gonzalez-Martinez
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, Ohio
- Department of Neurosurgery, Cleveland Clinic, Cleveland, Ohio
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9
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Abstract
Focal cortical dysplasia is a common cause of medication resistant epilepsy. A better understanding of its presentation, pathophysiology and consequences have helped us improved its treatment and outcome. This paper reviews the most recent classification, pathophysiology and imaging findings in clinical research as well as the knowledge gained from studying genetic and lesional animal models of focal cortical dysplasia. This review of this recently gained knowledge will most likely help develop new research models and new therapeutic targets for patients with epilepsy associated with focal cortical dysplasia.
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10
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Pennacchio P, Noé F, Gnatkovsky V, Moroni RF, Zucca I, Regondi MC, Inverardi F, de Curtis M, Frassoni C. Increased pCREB expression and the spontaneous epileptiform activity in a BCNU-treated rat model of cortical dysplasia. Epilepsia 2015; 56:1343-54. [DOI: 10.1111/epi.13070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Paolo Pennacchio
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Francesco Noé
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Vadym Gnatkovsky
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Ramona Frida Moroni
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Ileana Zucca
- Scientific Department; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Maria Cristina Regondi
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Francesca Inverardi
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Marco de Curtis
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
| | - Carolina Frassoni
- Clinical Epileptology and Experimental Neurophysiology Unit; IRCCS Foundation Neurological Institute “C. Besta”; Milano Italy
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Takano T, Matsui K. Increased expression of GAP43 in interneurons in a rat model of experimental polymicrogyria. J Child Neurol 2015; 30:716-28. [PMID: 25061039 DOI: 10.1177/0883073814541476] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 06/01/2014] [Indexed: 12/15/2022]
Abstract
To investigate seizure susceptibility in polymicrogyria, the seizure threshold and growth-associated protein GAP43 expression were analyzed in a rat experimental model of polymicrogyria induced by intracerebral injection of ibotenate. A total of 72 neonates from 9 pregnant rats were used. Intraperitoneal pentylenetetrazole injection did not induce any seizure activity in the control rats, although it elicited seizures of variable severity in the polymicrogyria rats. Fluoro-Jade B-positive degenerating interneurons were found in the polymicrogyria brains; however, no such neurons were detected in the control brains. In the polymicrogyria rats, the GAP43 expression was significantly and widely distributed in the brain, and the percentage of parvalbumin-positive interneurons in the GAP43-positive cells was significantly higher than that observed in the nonphosphorylated neurofilament-positive pyramidal cells. We conclude that the relatively selective vulnerability of inhibitory interneurons constitutes the basis for the decreased seizure threshold observed in this model of polymicrogyria.
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Affiliation(s)
- Tomoyuki Takano
- Department of Pediatrics, Shiga University of Medical Science, Seta-Tsukinowa, Otsu, Japan
| | - Katsuyuki Matsui
- Department of Pediatrics, Shiga University of Medical Science, Seta-Tsukinowa, Otsu, Japan
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12
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Models of cortical malformation--Chemical and physical. J Neurosci Methods 2015; 260:62-72. [PMID: 25850077 DOI: 10.1016/j.jneumeth.2015.03.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 03/27/2015] [Accepted: 03/30/2015] [Indexed: 11/21/2022]
Abstract
Pharmaco-resistant epilepsies, and also some neuropsychiatric disorders, are often associated with malformations in hippocampal and neocortical structures. The mechanisms leading to these cortical malformations causing an imbalance between the excitatory and inhibitory system are largely unknown. Animal models using chemical or physical manipulations reproduce different human pathologies by interfering with cell generation and neuronal migration. The model of in utero injection of methylazoxymethanol (MAM) acetate mimics periventricular nodular heterotopia. The freeze lesion model reproduces (poly)microgyria, focal heterotopia and schizencephaly. The in utero irradiation model causes microgyria and heterotopia. Intraperitoneal injections of carmustine 1-3-bis-chloroethyl-nitrosurea (BCNU) to pregnant rats produces laminar disorganization, heterotopias and cytomegalic neurons. The ibotenic acid model induces focal cortical malformations, which resemble human microgyria and ulegyria. Cortical dysplasia can be also observed following prenatal exposure to ethanol, cocaine or antiepileptic drugs. All these models of cortical malformations are characterized by a pronounced hyperexcitability, few of them also produce spontaneous epileptic seizures. This dysfunction results from an impairment in GABAergic inhibition and/or an increase in glutamatergic synaptic transmission. The cortical region initiating or contributing to this hyperexcitability may not necessarily correspond to the site of the focal malformation. In some models wide-spread molecular and functional changes can be observed in remote regions of the brain, where they cause pathophysiological activities. This paper gives an overview on different animal models of cortical malformations, which are mostly used in rodents and which mimic the pathology and to some extent the pathophysiology of neuronal migration disorders associated with epilepsy in humans.
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Zhou FW, Roper SN. Reduced chemical and electrical connections of fast-spiking interneurons in experimental cortical dysplasia. J Neurophysiol 2014; 112:1277-90. [PMID: 24944214 DOI: 10.1152/jn.00126.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Aberrant neural connections are regarded as a principal factor contributing to epileptogenesis. This study examined chemical and electrical connections between fast-spiking (FS), parvalbumin (PV)-immunoreactive (FS-PV) interneurons and regular-spiking (RS) neurons (pyramidal neurons or spiny stellate neurons) in a rat model of prenatal irradiation-induced cortical dysplasia. Presynaptic action potentials were evoked by current injection and the elicited unitary inhibitory or excitatory postsynaptic potentials (uIPSPs or uEPSPs) were recorded in the postsynaptic cell. In dysplastic cortex, connection rates between presynaptic FS-PV interneurons and postsynaptic RS neurons and FS-PV interneurons, and uIPSP amplitudes were significantly smaller than controls, but both failure rates and coefficient of variation of uIPSP amplitudes were larger than controls. In contrast, connection rates from RS neurons to FS-PV interneurons and uEPSPs amplitude were similar in the two groups. Assessment of the paired pulse ratio showed a significant decrease in synaptic release probability at FS-PV interneuronal terminals, and the density of terminal boutons on axons of biocytin-filled FS-PV interneurons was also decreased, suggesting presynaptic dysfunction in chemical synapses formed by FS-PV interneurons. Electrical connections were observed between FS-PV interneurons, and the connection rates and coupling coefficients were smaller in dysplastic cortex than controls. In dysplastic cortex, we found a reduced synaptic efficiency for uIPSPs originating from FS-PV interneurons regardless of the type of target cell, and impaired electrical connections between FS-PV interneurons. This expands our understanding of the fundamental impairment of inhibition in this model and may have relevance for certain types of human cortical dysplasia.
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Affiliation(s)
- Fu-Wen Zhou
- Department of Neurosurgery and the McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - Steven N Roper
- Department of Neurosurgery and the McKnight Brain Institute, University of Florida, Gainesville, Florida
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Roles of heat shock factor 1 in neuronal response to fetal environmental risks and its relevance to brain disorders. Neuron 2014; 82:560-72. [PMID: 24726381 DOI: 10.1016/j.neuron.2014.03.002] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2014] [Indexed: 12/25/2022]
Abstract
Prenatal exposure of the developing brain to various environmental challenges increases susceptibility to late onset of neuropsychiatric dysfunction; still, the underlying mechanisms remain obscure. Here we show that exposure of embryos to a variety of environmental factors such as alcohol, methylmercury, and maternal seizure activates HSF1 in cerebral cortical cells. Furthermore, Hsf1 deficiency in the mouse cortex exposed in utero to subthreshold levels of these challenges causes structural abnormalities and increases seizure susceptibility after birth. In addition, we found that human neural progenitor cells differentiated from induced pluripotent stem cells derived from schizophrenia patients show higher variability in the levels of HSF1 activation induced by environmental challenges compared to controls. We propose that HSF1 plays a crucial role in the response of brain cells to prenatal environmental insults and may be a key component in the pathogenesis of late-onset neuropsychiatric disorders.
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Shen HY, Sun H, Hanthorn MM, Zhi Z, Lan JQ, Poulsen DJ, Wang RK, Boison D. Overexpression of adenosine kinase in cortical astrocytes and focal neocortical epilepsy in mice. J Neurosurg 2013; 120:628-38. [PMID: 24266544 DOI: 10.3171/2013.10.jns13918] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
OBJECT New experimental models and diagnostic methods are needed to better understand the pathophysiology of focal neocortical epilepsies in a search for improved epilepsy treatment options. The authors hypothesized that a focal disruption of adenosine homeostasis in the neocortex might be sufficient to trigger electrographic seizures. They further hypothesized that a focal disruption of adenosine homeostasis might affect microcirculation and thus offer a diagnostic opportunity for the detection of a seizure focus located in the neocortex. METHODS Focal disruption of adenosine homeostasis was achieved by injecting an adeno-associated virus (AAV) engineered to overexpress adenosine kinase (ADK), the major metabolic clearance enzyme for the brain's endogenous anticonvulsant adenosine, into the neocortex of mice. Eight weeks following virus injection, the affected brain area was imaged via optical microangiography (OMAG) to detect changes in microcirculation. After completion of imaging, cortical electroencephalography (EEG) recordings were obtained from the imaged brain area. RESULTS Viral expression of the Adk cDNA in astrocytes generated a focal area (~ 2 mm in diameter) of ADK overexpression within the neocortex. OMAG scanning revealed a reduction in vessel density within the affected brain area of approximately 23% and 29% compared with control animals and the contralateral hemisphere, respectively. EEG recordings revealed electrographic seizures within the focal area of ADK overexpression at a rate of 1.3 ± 0.2 seizures per hour (mean ± SEM). CONCLUSIONS The findings of this study suggest that focal adenosine deficiency is sufficient to generate a neocortical focus of hyperexcitability, which is also characterized by reduced vessel density. The authors conclude that their model constitutes a useful tool to study neocortical epilepsies and that OMAG constitutes a noninvasive diagnostic tool for the imaging of seizure foci with disrupted adenosine homeostasis.
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Affiliation(s)
- Hai-Ying Shen
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute, Portland, Oregon
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Setkowicz Z, Gzieło-Jurek K, Uram Ł, Janicka D, Janeczko K. Brain dysplasia evoked by gamma irradiation at different stages of prenatal development leads to different tonic and clonic seizure reactivity. Epilepsy Res 2013; 108:66-80. [PMID: 24239322 DOI: 10.1016/j.eplepsyres.2013.10.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 09/27/2013] [Accepted: 10/18/2013] [Indexed: 11/17/2022]
Abstract
Rats with brain dysplasia evoked by interruption of different stages of prenatal neurogenesis show characteristic variations in susceptibility to seizures depending on the neurochemical specificity of pharmacological agents used to evoke seizures. To verify a discrepancy between the data obtained using different pharmacological models, neurochemically neutral electroshocks were applied here. To produce brain dysplasia of different degrees, pregnant Wistar rats were exposed to a single 1.0Gy dose of gamma rays on gestation days 13, 15, 17 or 19. From the postnatal day 60, their male offspring (E13s, E15s, E17s and E19s, respectively) were subjected to 21 daily electrical stimulations to evoke seizures. Profiles of tonic and clonic reactivity to electrical stimulation significantly differed from those observed following pilocarpine or kainic acid administration. E17s showed minimal intensity of tonic but maximal of clonic responses. On the contrary, very high tonic and low clonic reactivity was observed in E13s and E15s. Periventricular nodular heterotopias (PNHs) were observed exclusively in E15s and E17s. Generally, the size of PNHs was correlated positively with susceptibility to tonic seizures but negatively with susceptibility to clonic seizures. Analogous correlations with the size of the neocortex were opposite. E13s and E19s had brains devoid PNHs but showed high tonic seizure susceptibility similar to that in E15s. It can therefore be concluded that PNHs modified the type of seizure reactivity from tonic to clonic, depending of their size, but the presence of PNHs was not necessary for the development of seizure susceptibility itself.
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Affiliation(s)
- Zuzanna Setkowicz
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, ul. Gronostajowa 9, 30-387 Kraków, Poland
| | - Kinga Gzieło-Jurek
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, ul. Gronostajowa 9, 30-387 Kraków, Poland
| | - Łukasz Uram
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, ul. Gronostajowa 9, 30-387 Kraków, Poland
| | - Dominika Janicka
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, ul. Gronostajowa 9, 30-387 Kraków, Poland
| | - Krzysztof Janeczko
- Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, ul. Gronostajowa 9, 30-387 Kraków, Poland.
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Neurodegenerative Changes in Rat Hippocampal Fields during the Development of Pentylenetetrazole Kindling. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s11055-013-9777-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Najm I, Jehi L, Palmini A, Gonzalez-Martinez J, Paglioli E, Bingaman W. Temporal patterns and mechanisms of epilepsy surgery failure. Epilepsia 2013; 54:772-82. [DOI: 10.1111/epi.12152] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Imad Najm
- Epilepsy Center; Neurological Institute; Cleveland Clinic; Cleveland; Ohio; U.S.A
| | - Lara Jehi
- Epilepsy Center; Neurological Institute; Cleveland Clinic; Cleveland; Ohio; U.S.A
| | - Andre Palmini
- Porto Alegre Epilepsy Surgery Program; Neurology and Neurosurgery Services; Hospital São Lucas; Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS); Porto Alegre; Brazil
| | | | - Eliseu Paglioli
- Porto Alegre Epilepsy Surgery Program; Neurology and Neurosurgery Services; Hospital São Lucas; Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS); Porto Alegre; Brazil
| | - William Bingaman
- Epilepsy Center; Neurological Institute; Cleveland Clinic; Cleveland; Ohio; U.S.A
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Wong CH, Bleasel A, Wen L, Eberl S, Byth K, Fulham M, Somerville E, Mohamed A. Relationship between preoperative hypometabolism and surgical outcome in neocortical epilepsy surgery. Epilepsia 2012; 53:1333-40. [DOI: 10.1111/j.1528-1167.2012.03547.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Aniol VA, Stepanichev MY, Lazareva NA, Gulyaeva NV. An early decrease in cell proliferation after pentylenetetrazole-induced seizures. Epilepsy Behav 2011; 22:433-41. [PMID: 21907628 DOI: 10.1016/j.yebeh.2011.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Revised: 07/28/2011] [Accepted: 08/01/2011] [Indexed: 01/17/2023]
Abstract
There are increasing data on the influence of seizures on neurogenesis in the adult brain. However, data on cell proliferation and differentiation during the early stages of kindling are scarce. We have used pentylenetetrazole (PTZ)-induced kindling to investigate the temporal profile of cytogenesis in the germinative zones of adult rat brain. For comparison, we also used a single PTZ-induced generalized tonic-clonic seizure. During kindling development, the density of 5-bromo-2'-deoxyuridine-positive cells demonstrated similar changes in all germinative zones: a dramatic decrease after the first subthreshold PTZ injection, and a gradual increase to the control level following repeated PTZ administration. On the contrary, a single PTZ-induced generalized tonic-clonic seizure was followed by an increase in the number of proliferating cells in both the dentate gyrus and the subventricular zone. These results may indicate the existence of global mechanisms affecting cellular proliferation in adult brain during seizures. Different temporal profiles of neuronal damage and proliferation changes suggest that neurodegeneration is unlikely to be a global proliferation-regulating factor. The data may contribute to better understanding of the initial phase of kindling development and epileptogenesis.
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Affiliation(s)
- V A Aniol
- Department of Functional Biochemistry of Nervous System, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
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Min BK, Bystritsky A, Jung KI, Fischer K, Zhang Y, Maeng LS, In Park S, Chung YA, Jolesz FA, Yoo SS. Focused ultrasound-mediated suppression of chemically-induced acute epileptic EEG activity. BMC Neurosci 2011; 12:23. [PMID: 21375781 PMCID: PMC3061951 DOI: 10.1186/1471-2202-12-23] [Citation(s) in RCA: 183] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 03/06/2011] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Epilepsy is a common neurological disorder, which is attributed to uncontrollable abnormal hyper-excitability of neurons. We investigated the feasibility of using low-intensity, pulsed radiation of focused ultrasound (FUS) to non-invasively suppress epileptic activity in an animal model (rat), which was induced by the intraperitonial injection of pentylenetetrazol (PTZ). RESULTS After the onset of induced seizures, FUS was transcranially administered to the brain twice for three minutes each while undergoing electroencephalographic (EEG) monitoring. An air-backed, spherical segment ultrasound transducer (diameter: 6 cm; radius-of-curvature: 7 cm) operating at a fundamental frequency of 690 KHz was used to deliver a train of 0.5 msec-long pulses of sonication at a repetitive rate of 100 Hz to the thalamic areas of the brain. The acoustic intensity (130 mW/cm2) used in the experiment was sufficiently within the range of safety guidelines for the clinical ultrasound imaging. The occurrence of epileptic EEG bursts from epilepsy-induced rats significantly decreased after sonication when it was compared to the pre-sonication epileptic state. The PTZ-induced control group that did not receive any sonication showed a sustained number of epileptic EEG signal bursts. The animals that underwent sonication also showed less severe epileptic behavior, as assessed by the Racine score. Histological analysis confirmed that the sonication did not cause any damage to the brain tissue. CONCLUSIONS These results revealed that low-intensity, pulsed FUS sonication suppressed the number of epileptic signal bursts using acute epilepsy model in animal. Due to its non-invasiveness and spatial selectivity, FUS may offer new perspectives for a possible non-invasive treatment of epilepsy.
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Affiliation(s)
- Byoung-Kyong Min
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Alexander Bystritsky
- The Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Kwang-Ik Jung
- Department of Physical Medicine & Rehabilitation, Hallym University Sacred Heart Hospital, Medical College of Hallym University, Anyang, Korea
| | - Krisztina Fischer
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Yongzhi Zhang
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lee-So Maeng
- Institute of Catholic Integrative Medicine (ICIM), Incheon Saint Mary's Hospital, The Catholic University of Korea, Incheon, Korea
| | - Sang In Park
- Institute of Catholic Integrative Medicine (ICIM), Incheon Saint Mary's Hospital, The Catholic University of Korea, Incheon, Korea
| | - Yong-An Chung
- Institute of Catholic Integrative Medicine (ICIM), Incheon Saint Mary's Hospital, The Catholic University of Korea, Incheon, Korea
| | - Ferenc A Jolesz
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Seung-Schik Yoo
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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