1
|
Yavuz M, Akkol S, Onat F. Alpha-2a adrenergic receptor activation in genetic absence epilepsy: An absence status model? Epilepsia Open 2024; 9:534-547. [PMID: 38071480 PMCID: PMC10984306 DOI: 10.1002/epi4.12879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 12/07/2023] [Indexed: 04/04/2024] Open
Abstract
OBJECTIVE The objective of the study was to propose a candidate animal model of absence status epilepticus induced by specific alpha-2a adrenergic receptor (α2AR) activation. We also aim to investigate the responsiveness of this model to classical anti-status or anti-absence medications. METHODS An α2AR agonist, dexmedetomidine (DEX), was injected intracerebroventricularly into adult rats with genetic absence epilepsy, and their electroencephalography (EEG) was recorded. The total duration, number, and mean duration of each spike-and-wave discharges (SWDs) were evaluated. The blocks of absence status events were classified as the initial and second sets of absence statuses. Ethosuximide (ETX) was administered as a pretreatment to another group of rats and later injected with 2.5 μg DEX. In addition, ETX, valproic acid (VPA), diazepam (DIAZ), and atipamezole (ATI) were administered after induced status-like events following DEX administration. Power spectral characteristics and coherence analysis were performed on the EEG to assess the absence status events and sleep. RESULTS The 2.5 μg dose of DEX increased the total SWD duration and induced continuous SWDs up to 26 min. Following the initial absence status event, sleep was induced; then, the second period of absence status-like activities were initiated. ETX pretreatment blocked the occurrence of absence status-like activities. Power spectral density analyses revealed that DEX-induced post-sleep activities had higher power in delta frequency band (1-4 Hz) and attenuated power of 7 Hz harmonics (14 and 21 Hz) than the pre-injection seizure. The mean duration of SWDs were decreased in all the groups, but occasional prolonged activities were seen in ETX or VPA-injected rats but not with DIAZ or ATI. SIGNIFICANCE This study presents an absence status epilepticus animal model that is activated by α2AR activation to investigate the pathophysiological role of absence status. Unlike other agents ATI switched off the second set of absence statuses to normal SWDs, without sedation or lethargy, can show it may preferentially block absence status-like activity. THE PLAIN LANGUAGE SUMMARY This study proposes a rat model for prolonged seizures, resembling absence status epilepticus. Activating the brain's alpha-2a adrenergic receptor with dexmedetomidine induced seizures lasting up to 26 minutes. Ethosuximide pretreatment and post-treatment with valproic acid, diazepam, and atipamezole decreased induced seizures. The findings suggest this model is valuable for studying absence status epilepticus. In addition, atipamezole normalized abnormal seizures without sedation, hinting at its potential for targeted treatment and further research.
Collapse
Affiliation(s)
- Melis Yavuz
- Department of Pharmacology, Faculty of PharmacyAcibadem Mehmet Ali Aydinlar University UniversityIstanbulTurkey
| | - Serdar Akkol
- Department of NeurologyUniversity of Alabama at Birmingham Medical CenterBirminghamAlabamaUSA
| | - Filiz Onat
- Department of Medical Pharmacology, School of MedicineMarmara UniversityIstanbulTurkey
- Department of Medical Pharmacology, School of MedicineAcibadem Mehmet Ali Aydinlar UniversityIstanbulTurkey
| |
Collapse
|
2
|
Tran H, Mahzoum RE, Bonnot A, Cohen I. Epileptic seizure clustering and accumulation at transition from activity to rest in GAERS rats. Front Neurol 2024; 14:1296421. [PMID: 38328755 PMCID: PMC10847272 DOI: 10.3389/fneur.2023.1296421] [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: 09/18/2023] [Accepted: 12/14/2023] [Indexed: 02/09/2024] Open
Abstract
Knowing when seizures occur may help patients and can also provide insight into epileptogenesis mechanisms. We recorded seizures over periods of several days in the Genetic Absence Epileptic Rat from Strasbourg (GAERS) model of absence epilepsy, while we monitored behavioral activity with a combined head accelerometer (ACCEL), neck electromyogram (EMG), and electrooculogram (EOG). The three markers consistently discriminated between states of behavioral activity and rest. Both GAERS and control Wistar rats spent more time in rest (55-66%) than in activity (34-45%), yet GAERS showed prolonged continuous episodes of activity (23 vs. 18 min) and rest (34 vs. 30 min). On average, seizures lasted 13 s and were separated by 3.2 min. Isolated seizures were associated with a decrease in the power of the activity markers from steep for ACCEL to moderate for EMG and weak for EOG, with ACCEL and EMG power changes starting before seizure onset. Seizures tended to occur in bursts, with the probability of seizing significantly increasing around a seizure in a window of ±4 min. Furthermore, the seizure rate was strongly increased for several minutes when transitioning from activity to rest. These results point to mechanisms that control behavioral states as determining factors of seizure occurrence.
Collapse
|
3
|
Inherited pain hypersensitivity and increased anxiety-like behaviors are associated with genetic epilepsy in Wistar Audiogenic Rats: Short- and long-term effects of acute and chronic seizures on nociception and anxiety. Epilepsy Behav 2023; 141:109160. [PMID: 36907082 DOI: 10.1016/j.yebeh.2023.109160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/14/2023]
Abstract
Anxiety and pain hypersensitivity are neurobehavioral comorbidities commonly reported by patients with epilepsies, and preclinical models are suitable to investigate the neurobiology of behavioral and neuropathological alterations associated with these epilepsy-related comorbidities. This work aimed to characterize endogenous alterations in nociceptive threshold and anxiety-like behaviors in the Wistar Audiogenic Rat (WAR) model of genetic epilepsy. We also assessed the effects of acute and chronic seizures on anxiety and nociception. WARs from acute and chronic seizure protocols were divided into two groups to assess short- and long-term changes in anxiety (1 day or 15 days after seizures, respectively). To assess anxiety-like behaviors, the laboratory animals were submitted to the open field, light-dark box, and elevated plus maze tests. The von Frey, acetone, and hot plate tests were used to measure the endogenous nociception in seizure-free WARs, and postictal antinociception was recorded at 10, 30, 60, 120, 180 min, and 24 h after seizures. Seizure-free WARs presented increased anxiety-like behaviors and pain hypersensitivity, displaying mechanical and thermal allodynia (to heat and cold stimuli) in comparison to nonepileptic Wistar rats. Potent postictal antinociception that persisted for 120 to 180 min was detected after acute and chronic seizures. Additionally, acute and chronic seizures have magnified the expression of anxiety-like behaviors when assessed at 1 day and 15 days after seizures. Behavioral analysis indicated more severe and persistent anxiogenic-like alterations in WARs submitted to acute seizures. Therefore, WARs presented pain hypersensitivity and increased anxiety-like behaviors endogenously associated with genetic epilepsy. Acute and chronic seizures induced postictal antinociception in response to mechanical and thermal stimuli and increased anxiety-like behaviors when assessed 1 day and 15 days later. These findings support the presence of neurobehavioral alterations in subjects with epilepsy and shed light on the use of genetic models to characterize neuropathological and behavioral alterations associated with epilepsy.
Collapse
|
4
|
Fontes-Dutra M, Righes Marafiga J, Santos-Terra J, Deckmann I, Brum Schwingel G, Rabelo B, Kazmierzak de Moraes R, Rockenbach M, Vendramin Pasquetti M, Gottfried C, Calcagnotto ME. GABAergic synaptic transmission and cortical oscillation patterns in the primary somatosensory area of a valproic acid rat model of autism spectrum disorder. Eur J Neurosci 2023; 57:527-546. [PMID: 36504470 DOI: 10.1111/ejn.15893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 11/20/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022]
Abstract
Autism spectrum disorder (ASD) is characterized by impaired social communication and interaction associated with repetitive or stereotyped behaviour. Prenatal valproic acid (VPA) exposure in rodents is a commonly used model of ASD. Resveratrol (RSV) has been shown to prevent interneuronal and behavioural impairments in the VPA model. We investigated the effects of prenatal VPA exposure and RSV on the GABAergic synaptic transmission, brain oscillations and on the genic expression of interneuron-associated transcription factor LHX6 in the primary somatosensory area (PSSA). Prenatal VPA exposure decreased the sIPSC and mIPSC frequencies and the sIPSC decay kinetics onto layers 4/5 pyramidal cells of PSSA. About 40% of VPA animals exhibited absence-like spike-wave discharge (SWD) events associated with behaviour arrest and increased power spectrum density of delta, beta and gamma cortical oscillations. VPA animals had reduced LHX6 expression in PSSA, but VPA animals treated with RSV had no changes on synaptic inhibition or LHX6 expression in the PSSA. SWD events associated with behaviour arrest and the abnormal increment of cortical oscillations were also absent in VPA animals treated with RSV. These findings provide new venues to investigate the role of both RSV and VPA in the pathophysiology of ASD and highlight the VPA animal model as an interesting tool to investigate pathways related to the aetiology and possible future therapies to this neuropsychiatric disorder.
Collapse
Affiliation(s)
- Mellanie Fontes-Dutra
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Joseane Righes Marafiga
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Graduate Program in Biological Science: Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory, Department of Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Júlio Santos-Terra
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Iohanna Deckmann
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Gustavo Brum Schwingel
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Bruna Rabelo
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Rafael Kazmierzak de Moraes
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Marília Rockenbach
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Mayara Vendramin Pasquetti
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Graduate Program in Biological Science: Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory, Department of Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Carmem Gottfried
- Translational Research Group in Autism Spectrum Disorders (GETTEA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Maria Elisa Calcagnotto
- Department of Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Graduate Program in Biological Science: Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Neurophysiology and Neurochemistry of Neuronal Excitability and Synaptic Plasticity Laboratory, Department of Biochemistry, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Graduate Program in Neuroscience, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| |
Collapse
|
5
|
Ershova AS, Suleymanova EM, Grishchenko AA, Vinogradova L, Sysoev IV. Interhemispheric Symmetry and Asymmetry of Absence Type Spike-Wave Discharges Caused by Systemic Administration of Pentylenetetrazole. J EVOL BIOCHEM PHYS+ 2023. [DOI: 10.1134/s0022093023010246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
|
6
|
Sarkisova K, van Luijtelaar G. The impact of early-life environment on absence epilepsy and neuropsychiatric comorbidities. IBRO Neurosci Rep 2022; 13:436-468. [PMID: 36386598 PMCID: PMC9649966 DOI: 10.1016/j.ibneur.2022.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/30/2022] [Accepted: 10/31/2022] [Indexed: 11/11/2022] Open
Abstract
This review discusses the long-term effects of early-life environment on epileptogenesis, epilepsy, and neuropsychiatric comorbidities with an emphasis on the absence epilepsy. The WAG/Rij rat strain is a well-validated genetic model of absence epilepsy with mild depression-like (dysthymia) comorbidity. Although pathologic phenotype in WAG/Rij rats is genetically determined, convincing evidence presented in this review suggests that the absence epilepsy and depression-like comorbidity in WAG/Rij rats may be governed by early-life events, such as prenatal drug exposure, early-life stress, neonatal maternal separation, neonatal handling, maternal care, environmental enrichment, neonatal sensory impairments, neonatal tactile stimulation, and maternal diet. The data, as presented here, indicate that some early environmental events can promote and accelerate the development of absence seizures and their neuropsychiatric comorbidities, while others may exert anti-epileptogenic and disease-modifying effects. The early environment can lead to phenotypic alterations in offspring due to epigenetic modifications of gene expression, which may have maladaptive consequences or represent a therapeutic value. Targeting DNA methylation with a maternal methyl-enriched diet during the perinatal period appears to be a new preventive epigenetic anti-absence therapy. A number of caveats related to the maternal methyl-enriched diet and prospects for future research are discussed.
Collapse
Affiliation(s)
- Karine Sarkisova
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Butlerova str. 5a, Moscow 117485, Russia
| | - Gilles van Luijtelaar
- Donders Institute for Brain, Cognition, and Behavior, Donders Center for Cognition, Radboud University, Nijmegen, PO Box 9104, 6500 HE Nijmegen, the Netherlands
| |
Collapse
|
7
|
The role of thalamic group II mGlu receptors in health and disease. Neuronal Signal 2022; 6:NS20210058. [PMID: 36561092 PMCID: PMC9760452 DOI: 10.1042/ns20210058] [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: 08/12/2022] [Revised: 10/20/2022] [Accepted: 10/24/2022] [Indexed: 12/25/2022] Open
Abstract
The thalamus plays a pivotal role in the integration and processing of sensory, motor, and cognitive information. It is therefore important to understand how the thalamus operates in states of both health and disease. In the present review, we discuss the function of the Group II metabotropic glutamate (mGlu) receptors within thalamic circuitry, and how they may represent therapeutic targets in treating disease states associated with thalamic dysfunction.
Collapse
|
8
|
Wang R, Zhu W, Liang G, Xu J, Guo J, Wang L. Animal models for epileptic foci localization, seizure detection, and prediction by electrical impedance tomography. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2022; 13:e1619. [PMID: 36093634 DOI: 10.1002/wcs.1619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 07/08/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Surgical resection of lesions and closed-loop suppression are the two main treatment options for patients with refractory epilepsy whose symptoms cannot be managed with medicines. Unfortunately, failures in foci localization and seizure prediction are constraining these treatments. Electrical impedance tomography (EIT), sensitive to impedance changes caused by blood flow or cell swelling, is a potential new way to locate epileptic foci and predict seizures. Animal validation is a necessary research process before EIT can be used in clinical practice, but it is unclear which among the many animal epilepsy models is most suited to this task. The selection of an animal model of epilepsy that is similar to human seizures and can be adapted to EIT is important for the accuracy and reliability of EIT research results. This study provides an overview of the animal models of epilepsy that have been used in research on the use of EIT to locate the foci or predict seizures; discusses the advantages and disadvantages of these models regarding inducement by chemical convulsant and electrical stimulation; and finally proposes optimal animal models of epilepsy to obtain more convincing research results for foci localization and seizure prediction by EIT. The ultimate goal of this study is to facilitate the development of new treatments for patients with refractory epilepsy. This article is categorized under: Neuroscience > Clinical Neuroscience Psychology > Brain Function and Dysfunction.
Collapse
Affiliation(s)
- Rong Wang
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Wenjing Zhu
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Guohua Liang
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Jiaming Xu
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Jie Guo
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| | - Lei Wang
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, China
| |
Collapse
|
9
|
Chakraborty S, Parayil R, Mishra S, Nongthomba U, Clement JP. Epilepsy Characteristics in Neurodevelopmental Disorders: Research from Patient Cohorts and Animal Models Focusing on Autism Spectrum Disorder. Int J Mol Sci 2022; 23:ijms231810807. [PMID: 36142719 PMCID: PMC9501968 DOI: 10.3390/ijms231810807] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
Epilepsy, a heterogeneous group of brain-related diseases, has continued to significantly burden society and families. Epilepsy comorbid with neurodevelopmental disorders (NDDs) is believed to occur due to multifaceted pathophysiological mechanisms involving disruptions in the excitation and inhibition (E/I) balance impeding widespread functional neuronal circuitry. Although the field has received much attention from the scientific community recently, the research has not yet translated into actionable therapeutics to completely cure epilepsy, particularly those comorbid with NDDs. In this review, we sought to elucidate the basic causes underlying epilepsy as well as those contributing to the association of epilepsy with NDDs. Comprehensive emphasis is put on some key neurodevelopmental genes implicated in epilepsy, such as MeCP2, SYNGAP1, FMR1, SHANK1-3 and TSC1, along with a few others, and the main electrophysiological and behavioral deficits are highlighted. For these genes, the progress made in developing appropriate and valid rodent models to accelerate basic research is also detailed. Further, we discuss the recent development in the therapeutic management of epilepsy and provide a briefing on the challenges and caveats in identifying and testing species-specific epilepsy models.
Collapse
Affiliation(s)
- Sukanya Chakraborty
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
| | - Rrejusha Parayil
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
| | - Shefali Mishra
- Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bengaluru 560012, India
| | - Upendra Nongthomba
- Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bengaluru 560012, India
| | - James P. Clement
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
- Correspondence: ; Tel.: +91-08-2208-2613
| |
Collapse
|
10
|
Klippel Zanona Q, Alves Marconi G, de Sá Couto Pereira N, Lazzarotto G, Luiza Ferreira Donatti A, Antonio Cortes de Oliveira J, Garcia-Cairasco N, Elisa Calcagnotto M. Absence-like seizures, cortical oscillations abnormalities and decreased anxiety-like behavior in Wistar Audiogenic Rats with cortical microgyria. Neuroscience 2022; 500:26-40. [DOI: 10.1016/j.neuroscience.2022.07.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 06/25/2022] [Accepted: 07/29/2022] [Indexed: 10/16/2022]
|
11
|
Neuroplastic alterations in cannabinoid receptors type 1 (CB1) in animal models of epileptic seizures. Neurosci Biobehav Rev 2022; 137:104675. [PMID: 35460705 DOI: 10.1016/j.neubiorev.2022.104675] [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: 02/06/2022] [Revised: 03/16/2022] [Accepted: 04/17/2022] [Indexed: 01/01/2023]
Abstract
Currently, there is an urgent need to better comprehend neuroplastic alterations in cannabinoid receptors type 1 (CB1) and to understand the biological meaning of these alterations in epileptic disorders. The present study reviewed neuroplastic changes in CB1 distribution, expression, and functionality in animal models of epileptic seizures. Neuroplastic alterations in CB1 were consistently observed in chemical, genetic, electrical, and febrile seizure models. Most studies assessed changes in hippocampal and cortical CB1, while thalamic, hypothalamic, and brainstem nuclei were rarely investigated. Additionally, the relationship between CB1 alteration and the control of brain excitability through modulation of specific neuronal networks, such as striatonigral, nigrotectal and thalamocortical pathways, and inhibitory projections to hippocampal pyramidal neurons, were all presented and discussed in the present review. Neuroplastic alterations in CB1 detected in animal models of epilepsy may reflect two different scenarios: (1) endogenous adaptations aimed to control neuronal hyperexcitability in epilepsy or (2) pathological alterations that facilitate neuronal hyperexcitability. Additionally, a better comprehension of neuroplastic and functional alterations in CB1 can improve pharmacological therapies for epilepsies and their comorbidities.
Collapse
|
12
|
Çarçak N, Karanfil C, Akat Ş, Akman Ö, Onat F. The effect of chronic treatment with sodium channel blocker lacosamide on early development of absence seizures in genetic absence epilepsy rats. Epilepsy Res 2022; 182:106896. [DOI: 10.1016/j.eplepsyres.2022.106896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 02/07/2022] [Accepted: 03/04/2022] [Indexed: 11/03/2022]
|
13
|
Ozgur M, Özyurt MG, Arkan S, Cavdar S. The Effects of Optogenetic Activation of Astrocytes on Spike-and-Wave Discharges in Genetic Absence Epileptic Rats. Ann Neurosci 2022; 29:53-61. [PMID: 35875425 PMCID: PMC9305907 DOI: 10.1177/09727531211072423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/29/2021] [Indexed: 11/16/2022] Open
Abstract
Background: Absence seizures (petit mal seizures) are characterized by a brief loss of consciousness without loss of postural tone. The disease is diagnosed by an electroencephalogram (EEG) showing spike–wave discharges (SWD) caused by hypersynchronous thalamocortical (TC) oscillations. There has been an explosion of research highlighting the role of astrocytes in supporting and modulating neuronal activity. Despite established in vitro evidence, astrocytes’ influence on the TC network remains to be elucidated in vivo in the absence epilepsy (AE). Purpose: In this study, we investigated the role of astrocytes in the generation and modulation of SWDs. We hypothesize that disturbances in astrocytes’ function may affect the pathomechanism of AE. Methods: To direct the expression of channelrhodopsin-2 (ChR2) rAAV8-GFAP-ChR2(H134R)-EYFP or to control the effect of surgical intervention, AAV-CaMKIIa-EYFP was injected into the ventrobasal nucleus (VB) of the thalamus of 18 animals. After four weeks following the injection, rats were stimulated using blue light (~473 nm) and, simultaneously, the electrophysiological activity of the frontal cortical neurons was recorded for three consecutive days. The animals were then perfused, and the brain tissue was analyzed by confocal microscopy. Results: A significant increase in the duration of SWD without affecting the number of SWD in genetic absence epileptic rats from Strasbourg (GAERS) compared to control injections was observed. The duration of the SWD was increased from 12.50 ± 4.41 s to 17.44 ± 6.07 following optogenetic stimulation in GAERS. The excitation of the astrocytes in Wistar Albino Glaxo Rijswijk (WAG-Rij) did not change the duration of SWD; however, stimulation resulted in a significant increase in the number of SWD from 18.52 ± 11.46 bursts/30 min to 30.17 ± 18.43 bursts/30 min. Whereas in control injection, the duration and the number of SWDs were similar at pre- and poststimulus. Both the background and poststimulus average firing rates of the SWD in WAG-Rij were significantly higher than the firing recorded in GAERS. Conclusion: These findings suggest that VB astrocytes play a role in modulating the SWD generation in both rat models with distinct mechanisms and can present an essential target for the possible therapeutic approach for AE.
Collapse
Affiliation(s)
- Merve Ozgur
- Graduate School of Health Sciences, Division of Neuroscience, Koc University, Istanbul Turkey
- Department of Anatomy, Faculty of Medicine, Izmir University of Economics, Izmir, Turkey
- Department of Anatomy, Koç University School of Medicine, Istanbul, Turkey
| | - Mustafa Görkem Özyurt
- Department of Anatomy, Koç University School of Medicine, Istanbul, Turkey
- Graduate School of Sciences and Engineering, Koç University, Istanbul, Turkey
| | - Sertan Arkan
- Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Safiye Cavdar
- Department of Experimental Medical Science, Molecular Neurobiology Unit, Lund University, Lund, Sweden
| |
Collapse
|
14
|
Abdelaal MS, Midorikawa M, Suzuki T, Kobayashi K, Takata N, Miyata M, Mimura M, Tanaka KF. OUP accepted manuscript. Brain Commun 2022; 4:fcac010. [PMID: 35243344 PMCID: PMC8887905 DOI: 10.1093/braincomms/fcac010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/02/2021] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
Spike-and-wave discharges and an accompanying loss of consciousness are hallmarks of absence seizure, which is a childhood generalized epilepsy disorder. In absence seizure, dysfunction of the cortico-thalamo-cortico circuitry is thought to engage in abnormal cortical rhythms. Previous studies demonstrated that the thalamic reticular nucleus has a critical role in the formation of normal cortical rhythms; however, whether thalamic reticular nucleus dysfunction leads directly to abnormal rhythms, such as epilepsy, is largely unknown. We found that expressing the inhibitory opsin, archaerhodopsin, including in the thalamic reticular nucleus, caused abnormal cortical rhythms in Pvalb-tetracycline transactivator::tetO-ArchT (PV-ArchT) double transgenic mice. We validated the PV-ArchT line as a new mouse model of absence seizure through physiological and pharmacological analyses, as well as through examining their behavioural features. We then discovered that archaerhodopsin expression exclusively in thalamic reticular nucleus parvalbumin-positive neurons was sufficient to induce cortical spike-and-wave discharges using adeno-associated virus-mediated thalamic reticular nucleus targeting. Furthermore, we found that archaerhodopsin expression impaired rebound burst firing and T-current in thalamic reticular nucleus parvalbumin-positive cells by slice physiology. Although T-current in the thalamic reticular nucleus was impaired, the T-current blocker ethosuximide still had a therapeutic effect in PV-ArchT mice, suggesting a gain of function of T-type calcium channels in this absence seizure model. However, we did not find any over- or misexpression of T-type calcium channel genes in the thalamus or the cortex. Thus, we demonstrated that thalamic reticular nucleus dysfunction led to an absence seizure-like phenotype in mice. In a final set of experiments, we showed that the archaerhodopsin-mediated absence seizure-like phenotype disappeared after the removal of archaerhodopsin by using a time-controllable transgenic system. These data may provide a hint as to why many absence seizures naturally regress.
Collapse
Affiliation(s)
- Manal S. Abdelaal
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Mitsuharu Midorikawa
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women’s Medical University, Tokyo 162-8666, Japan
| | - Toru Suzuki
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Norio Takata
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Mariko Miyata
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women’s Medical University, Tokyo 162-8666, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kenji F. Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo 160-8582, Japan
- Correspondence to: Kenji F. Tanaka, MD, PhD Division of Brain Sciences, Institute for Advanced Medical Research Keio University School of Medicine 35 Shinanomachi Shinjuku-ku Tokyo 160-8582, Japan E-mail:
| |
Collapse
|
15
|
Tugba EK, Medine GIO, Ozlem A, Deniz K, Filiz OY. Prolongation of absence seizures and changes in serotonergic and dopaminergic neurotransmission by nigrostriatal pathway degeneration in genetic absence epilepsy rats. Pharmacol Biochem Behav 2021; 213:173317. [PMID: 34974062 DOI: 10.1016/j.pbb.2021.173317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 12/22/2021] [Accepted: 12/22/2021] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Basal ganglia structures play an important role in the pathophysiology of absence epilepsy, known as remote control of absence seizures. We examined the role of the nigrostriatal dopaminergic pathway in absence epilepsy through behavioral and electroencephalography (EEG) parameters, immunohistochemical, and biochemical characteristics of dopamine and serotonin in the genetic absence epilepsy rat model. METHODS The nigrostriatal pathway was degenerated by the injection of chemical 6-hydroxydopamine hydrobromide (6-OHDA) into the medial forebrain bundle (MFB) in Wistar and genetic absence epilepsy rats from Strasbourg (GAERS). On the 21st day after stereotaxic surgery, spike-and-wave discharges (SWDs) on EEG were recorded in GAERS groups. Thereafter, Wistar-Control, GAERS-Control, Wistar-6OHDA, GAERS-6OHDA rats were subjected to the cylinder and apomorphine-induced rotation tests. Dopaminergic or serotonergic immunoreactivity was examined in the cortex, striatum, and substantia nigra pars compacta. High-performance liquid chromatography method was used for biochemical analysis of dopamine and serotonin in the cortex and thalamus. RESULTS In behavioral analysis, the number of rotations in the GAERS-6OHDA group was significantly higher than in Wistar-6OHDA rats. The degeneration of the nigrostriatal dopaminergic pathway produced a significant increase in the cumulative duration of SWDs and the duration of each SWD in GAERS-6OHDA rats. GAERS-Control rats displayed significantly higher cortical and striatal serotonin immunoreactivity and cortical serotonin level compared to Wistar-Control animals. Moreover, cortical and striatal serotonin immunoreactivity and cortical serotonin levels increased in Wistar-6OHDA and GAERS-6OHDA groups compared to their control groups. SIGNIFICANCE The effect of 6-OHDA-induced MFB lesion on absence epilepsy was examined for the first time by comparing Wistar and GAERS rats. The nigrostriatal dopaminergic pathway as a part of the remote-control system is likely to participate in the seizure network.
Collapse
Affiliation(s)
- Eryigit Karamahmutoglu Tugba
- Department of Medical Pharmacology, Marmara University Faculty of Medicine, Istanbul, Turkey; Brain Repair and Imaging in Neural Systems (B.R.A.I.N.S) Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Gulcebi Idriz Oglu Medine
- Department of Medical Pharmacology, Marmara University Faculty of Medicine, Istanbul, Turkey; Epilepsy Research Centre (EPAM), Marmara University, Istanbul, Turkey
| | - Akman Ozlem
- Department of Physiology, Demiroglu Bilim University Faculty of Medicine, Istanbul, Turkey
| | - Kirik Deniz
- Brain Repair and Imaging in Neural Systems (B.R.A.I.N.S) Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Onat Yilmaz Filiz
- Department of Medical Pharmacology, Faculty of Medicine, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey.
| |
Collapse
|
16
|
Sitnikova E. Sleep Disturbances in Rats With Genetic Pre-disposition to Spike-Wave Epilepsy (WAG/Rij). Front Neurol 2021; 12:766566. [PMID: 34803898 PMCID: PMC8602200 DOI: 10.3389/fneur.2021.766566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 10/01/2021] [Indexed: 11/13/2022] Open
Abstract
Wistar Albino Glaxo Rijswijk (WAG/Rij) rats are widely used in basic and pre-clinical studies as a valid genetic model of absence epilepsy. Adult WAG/Rij rats exhibit generalized 8–10-Hz spike-wave discharges (SWDs) in the electroencephalogram. SWDs are known to result from thalamocortical circuit dysfunction, and this implies an intimate relationship between slow-wave EEG activity, sleep spindles, and SWDs. The present mini review summarizes relevant research on sleep-related disturbances associated with spike-wave epilepsy in WAG/Rij rats in the domain of slow-wave sleep EEG and microarousals. It also discusses enhancement of the intermediate stage of sleep. In general, sleep EEG studies provide important information about epileptogenic processes related to spike-wave epilepsy.
Collapse
Affiliation(s)
- Evgenia Sitnikova
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences (RAS), Moscow, Russia
| |
Collapse
|
17
|
Akman O, Briggs SW, Mowrey WB, Moshé SL, Galanopoulou AS. Antiepileptogenic effects of rapamycin in a model of infantile spasms due to structural lesions. Epilepsia 2021; 62:1985-1999. [PMID: 34212374 DOI: 10.1111/epi.16975] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/01/2021] [Accepted: 06/08/2021] [Indexed: 12/22/2022]
Abstract
OBJECTIVE Infantile spasms may evolve into persistent epilepsies including Lennox-Gastaut syndrome. We compared adult epilepsy outcomes in models of infantile spasms due to structural etiology (multiple-hit model) or focal cortical inflammation and determined the anti-epileptogenic effects of pulse-rapamycin, previously shown to stop spasms in multiple-hit rats. METHODS Spasms were induced in 3-day-old male rats via right intracerebral doxorubicin/lipopolysaccharide (multiple-hit model) infusions. Controls and sham rats were used. Separate multiple-hit rats received pulse-rapamycin or vehicle intraperitoneally between postnatal days 4 and 6. In adult mice, video-EEG (electroencephalography) scoring for seizures and sleep and histology were done blinded to treatment. RESULTS Motor-type seizures developed in 66.7% of multiple-hit rats, usually from sleep, but were reduced in the pulse-rapamycin-treated group (20%, p = .043 vs multiple-hit) and rare in other groups (0-9.1%, p < .05 vs multiple-hit). Spike-and-wave bursts had a slower frequency in multiple-hit rats (5.4-5.8Hz) than in the other groups (7.6-8.3Hz) (p < .05); pulse rapamycin had no effect on the hourly spike-and-wave burst rates in adulthood. Rapamycin, however, reduced the time spent in slow-wave-sleep (17.2%), which was increased in multiple-hit rats (71.6%, p = .003). Sham rats spent more time in wakefulness (43.7%) compared to controls (30.6%, p = .043). Multiple-hit rats, with or without rapamycin treatment, had right more than left corticohippocampal, basal ganglia lesions. There was no macroscopic pathology in the other groups. SIGNIFICANCE Structural corticohippocampal/basal ganglia lesions increase the risk for post-infantile spasms epilepsy, Lennox-Gastaut syndrome features, and sleep dysregulation. Pulse rapamycin treatment for infantile spasms has anti-epileptogenic effects, despite the structural lesions, and decreases the time spent in slow wave sleep.
Collapse
Affiliation(s)
- Ozlem Akman
- Saul R. Korey Department of Neurology, Laboratory of Developmental Epilepsy, Bronx, New York, USA
| | - Stephen W Briggs
- Saul R. Korey Department of Neurology, Laboratory of Developmental Epilepsy, Bronx, New York, USA
| | - Wenzhu B Mowrey
- Division of Biostatistics, Department of Epidemiology and Population Health, Bronx, New York, USA
| | - Solomon L Moshé
- Saul R. Korey Department of Neurology, Laboratory of Developmental Epilepsy, Bronx, New York, USA.,Isabelle Rapin Division of Child Neurology, Dominick P. Purpura Department of Neuroscience, Montefiore/Einstein Epilepsy Center, Bronx, New York, USA.,Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Aristea S Galanopoulou
- Saul R. Korey Department of Neurology, Laboratory of Developmental Epilepsy, Bronx, New York, USA.,Isabelle Rapin Division of Child Neurology, Dominick P. Purpura Department of Neuroscience, Montefiore/Einstein Epilepsy Center, Bronx, New York, USA
| |
Collapse
|
18
|
Absence epilepsy in male and female WAG/Rij rats: A longitudinal EEG analysis of seizure expression. Epilepsy Res 2021; 176:106693. [PMID: 34225231 DOI: 10.1016/j.eplepsyres.2021.106693] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 05/15/2021] [Accepted: 06/18/2021] [Indexed: 12/26/2022]
Abstract
The WAG/Rij strain of rats is commonly used as a preclinical model of genetic absence epilepsy. While widely utilized, the developmental trajectory of absence seizure expression has been only partially described. Moreover, sex differences in this strain have been under-explored. Here, we longitudinally monitored male and female WAG/Rij rats to quantify cortical spike-and-wave discharges (SWDs) monthly, from 4 to 10 months of age. In both male and female WAG/Rij rats, absence seizure susceptibility increased with age. In contrast to previous reports, we found a robust and consistent increase in absence epilepsy susceptibility in male WAG/Rij rats in comparison to females across months. The increased absence seizure susceptibility was characterized by increased number and duration of SWDs, and consequently increased total SWDs duration. These findings highlight a previously un-recognized sex difference in a model of absence epilepsy and narrow the knowledge gap of age-dependent expression of SWDs in the WAG/Rij strain.
Collapse
|
19
|
Almeida CGM, Costa-Higuchi K, Piovesan AR, Moro CF, Venturin GT, Greggio S, Costa-Ferro ZS, Salamoni SD, Peigneur S, Tytgat J, de Lima ME, Silva CND, Vinadé L, Rowan EG, DaCosta JC, Dal Belo CA, Carlini CR. Neurotoxic and convulsant effects induced by jack bean ureases on the mammalian nervous system. Toxicology 2021; 454:152737. [PMID: 33631299 DOI: 10.1016/j.tox.2021.152737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/18/2021] [Accepted: 02/20/2021] [Indexed: 12/14/2022]
Abstract
Ureases are microbial virulence factors either because of the enzymatic release of ammonia or due to many other non-enzymatic effects. Here we studied two neurotoxic urease isoforms, Canatoxin (CNTX) and Jack Bean Urease (JBU), produced by the plant Canavalia ensiformis, whose mechanisms of action remain elusive. The neurotoxins provoke convulsions in rodents (LD50 ∼2 mg/kg) and stimulate exocytosis in cell models, affecting intracellular calcium levels. Here, electrophysiological and brain imaging techniques were applied to elucidate their mode of action. While systemic administration of the toxins causes tonic-clonic seizures in rodents, JBU injected into rat hippocampus induced spike-wave discharges similar to absence-like seizures. JBU reduced the amplitude of compound action potential from mouse sciatic nerve in a tetrodotoxin-insensitive manner. Hippocampal slices from CNTX-injected animals or slices treated in vitro with JBU failed to induce long term potentiation upon tetanic stimulation. Rat cortical synaptosomes treated with JBU released L-glutamate. JBU increased the intracellular calcium levels and spontaneous firing rate in rat hippocampus neurons. MicroPET scans of CNTX-injected rats revealed increased [18]Fluoro-deoxyglucose uptake in epileptogenesis-related areas like hippocampus and thalamus. Curiously, CNTX did not affect voltage-gated sodium, calcium or potassium channels currents, neither did it interfere on cholinergic receptors, suggesting an indirect mode of action that could be related to the ureases' membrane-disturbing properties. Understanding the neurotoxic mode of action of C. ensiformis ureases could help to unveil the so far underappreciated relevance of these toxins in diseases caused by urease-producing microorganisms, in which the human central nervous system is affected.
Collapse
Affiliation(s)
- Carlos Gabriel Moreira Almeida
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Medicine and Health Sciences, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Kiyo Costa-Higuchi
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Materials Technology and Engineering, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Angela Regina Piovesan
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Celular and Molecular Biology, Center of Biotechnology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Carlo Frederico Moro
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Medicine and Health Sciences, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Gianina Teribele Venturin
- Preclinical Research Center, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Samuel Greggio
- Preclinical Research Center, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Zaquer Susana Costa-Ferro
- Laboratory of Neuroscience, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Simone Denise Salamoni
- Laboratory of Neuroscience, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Steve Peigneur
- Laboratory of Toxicology & Pharmacology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Jan Tytgat
- Laboratory of Toxicology & Pharmacology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Maria Elena de Lima
- Institute of Teaching and Research, Santa Casa de Belo Horizonte, Belo Horizonte, MG, Brazil
| | | | - Lúcia Vinadé
- Laboratory of Neurobiology and Toxinology (Lanetox), Universidade Federal do Pampa, São Gabriel, RS, Brazil
| | - Edward G Rowan
- Strathclyde Institute for Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Jaderson Costa DaCosta
- Laboratory of Neuroscience, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Cháriston André Dal Belo
- Laboratory of Neurobiology and Toxinology (Lanetox), Universidade Federal do Pampa, São Gabriel, RS, Brazil.
| | - Celia Regina Carlini
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Medicine and Health Sciences, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Scholl of Medicine, Pontificía Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
| |
Collapse
|
20
|
Onat FY, Eşkazan E. Are Absence and Limbic Seizures Mutually Exclusive?: An Experimental Approach to Enigmatic Clinical Concept. JOURNAL OF PEDIATRIC EPILEPSY 2021. [DOI: 10.1055/s-0041-1722870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AbstractThe impressive advances in the several disciplines including neurophysiology, molecular biology, neuroimmunology, neurogenetics, neuroimaging, and neuropharmacology of epilepsies have been stimulating a mutual interaction among basic scientists, clinicians, and professionals from other disciplines, leading to the identification of clinical questions and then the design of basic science paradigms to test enigmatic clinical issues. Based on a clinical observation that the coexistence of genetic (idiopathic) generalized typical absence and mesial temporal lobe epilepsy in the same patient is extremely rare and debatable, we addressed the rare coexistence in the same individual, designed an experimental approach to test the validity of this clinical concept and to study the underlying mechanisms involved. Here we presented evidence of a mutual cross-interaction in the circuits involved in typical absence and temporal lobe epilepsy. This article delineates a phenomenological picture and comprehends a theoretical understanding of a mutual cross-interaction in typical absence as a representative of genetic generalized epilepsies and limbic epilepsy in which seizures often start from the mesial temporal lobe.
Collapse
Affiliation(s)
- Filiz Yılmaz Onat
- Department of Medical Pharmacology, School of Medicine, Acıbadem Mehmet Ali Aydınlar University, Istanbul, Turkey
- Department of Medical Pharmacology, Faculty of Medicine, Marmara University, Istanbul, Turkey
| | - Esat Eşkazan
- Department of Pharmacology, Cerrahpaşa School of Medicine, Istanbul, Turkey
| |
Collapse
|
21
|
Alyenbaawi H, Allison WT, Mok SA. Prion-Like Propagation Mechanisms in Tauopathies and Traumatic Brain Injury: Challenges and Prospects. Biomolecules 2020; 10:E1487. [PMID: 33121065 PMCID: PMC7692808 DOI: 10.3390/biom10111487] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/22/2020] [Accepted: 10/23/2020] [Indexed: 12/23/2022] Open
Abstract
The accumulation of tau protein in the form of filamentous aggregates is a hallmark of many neurodegenerative diseases such as Alzheimer's disease (AD) and chronic traumatic encephalopathy (CTE). These dementias share traumatic brain injury (TBI) as a prominent risk factor. Tau aggregates can transfer between cells and tissues in a "prion-like" manner, where they initiate the templated misfolding of normal tau molecules. This enables the spread of tau pathology to distinct parts of the brain. The evidence that tauopathies spread via prion-like mechanisms is considerable, but work detailing the mechanisms of spread has mostly used in vitro platforms that cannot fully reveal the tissue-level vectors or etiology of progression. We review these issues and then briefly use TBI and CTE as a case study to illustrate aspects of tauopathy that warrant further attention in vivo. These include seizures and sleep/wake disturbances, emphasizing the urgent need for improved animal models. Dissecting these mechanisms of tauopathy progression continues to provide fresh inspiration for the design of diagnostic and therapeutic approaches.
Collapse
Affiliation(s)
- Hadeel Alyenbaawi
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Medical Laboratories, Majmaah University, Majmaah 11952, Saudi Arabia
| | - W. Ted Allison
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
| | - Sue-Ann Mok
- Centre for Prions & Protein Folding Disease, University of Alberta, Edmonton, AB T6G 2M8, Canada; (H.A.); (W.T.A.)
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| |
Collapse
|
22
|
Dynamical mesoscale model of absence seizures in genetic models. PLoS One 2020; 15:e0239125. [PMID: 32991590 PMCID: PMC7524004 DOI: 10.1371/journal.pone.0239125] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 08/31/2020] [Indexed: 12/20/2022] Open
Abstract
A mesoscale network model is proposed for the development of spike and wave discharges (SWDs) in the cortico-thalamo-cortical (C-T-C) circuit. It is based on experimental findings in two genetic models of childhood absence epilepsy–rats of WAG/Rij and GAERS strains. The model is organized hierarchically into two levels (brain structures and individual neurons) and composed of compartments for representation of somatosensory cortex, reticular and ventroposteriomedial thalamic nuclei. The cortex and the two thalamic compartments contain excitatory and inhibitory connections between four populations of neurons. Two connected subnetworks both including relevant parts of a C-T-C network responsible for SWD generation are modelled: a smaller subnetwork for the focal area in which the SWD generation can take place, and a larger subnetwork for surrounding areas which can be only passively involved into SWDs, but which is mostly responsible for normal brain activity. This assumption allows modeling of both normal and SWD activity as a dynamical system (no noise is necessary), providing reproducibility of results and allowing future analysis by means of theory of dynamical system theories. The model is able to reproduce most time-frequency changes in EEG activity accompanying the transition from normal to epileptiform activity and back. Three different mechanisms of SWD initiation reported previously in experimental studies were successfully reproduced in the model. The model incorporates also a separate mechanism for the maintenance of SWDs based on coupling analysis from experimental data. Finally, the model reproduces the possibility to stop ongoing SWDs with high frequency electrical stimulation, as described in the literature.
Collapse
|
23
|
Smyk MK, van Luijtelaar G. Circadian Rhythms and Epilepsy: A Suitable Case for Absence Epilepsy. Front Neurol 2020; 11:245. [PMID: 32411068 PMCID: PMC7198737 DOI: 10.3389/fneur.2020.00245] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/13/2020] [Indexed: 11/16/2022] Open
Abstract
Many physiological processes such as sleep, hormonal secretion, or thermoregulation, are expressed as daily rhythms orchestrated by the circadian timing system. A powerful internal clock mechanism ensures proper synchronization of vital functions within an organism on the one hand, and between the organism and the external environment on the other. Some of the pathological processes developing in the brain and body are subjected to circadian modulation as well. Epilepsy is one of the conditions which symptoms often worsen at a very specific time of a day. Variation in peak occurrence depends on the syndrome and localization of the epileptic focus. Moreover, the timing of some types of seizures is closely related to the sleep-wake cycle, one of the most prominent circadian rhythms. This review focuses on childhood absence epilepsy (CAE), a genetic generalized epilepsy syndrome, in which both, the circadian and sleep influences play a significant role in manifestation of symptoms. Human and animal studies report rhythmical occurrence of spike-wave discharges (SWDs), an EEG hallmark of CAE. The endogenous nature of the SWDs rhythm has been confirmed experimentally in a genetic animal model of the disease, rats of the WAG/Rij strain. Well-known detrimental effects of circadian misalignment were demonstrated to impact the severity of ongoing epileptic activity. SWDs are vigilance-dependent in both humans and animal models, occurring most frequently during passive behavioral states and light slow-wave sleep. The relationship with the sleep-wake cycle seems to be bidirectional, while sleep shapes the rhythm of seizures, epileptic phenotype changes sleep architecture. Circadian factors and the sleep-wake states dependency have a potential as add-ons in seizures' forecasting. Stability of the rhythm of recurrent seizures in individual patients has been already used as a variable which refines existing algorithms for seizures' prediction. On the other hand, apart from successful pharmacological approach, circadian hygiene including sufficient sleep and avoidance of internal desynchronization or sleep loss, may be beneficial for patients with epilepsy in everyday management of seizures.
Collapse
Affiliation(s)
- Magdalena K Smyk
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, Netherlands
| | - Gilles van Luijtelaar
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands
| |
Collapse
|
24
|
Pharmacologically induced absence seizures versus kindling in Wistar rats. North Clin Istanb 2020; 7:25-34. [PMID: 32232200 PMCID: PMC7103736 DOI: 10.14744/nci.2019.80664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 01/03/2019] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVE: This study aimed to investigate the effects of γ-butyrolactone (GBL), a prodrug of gamma-Hydroxybutyric acid -induced absence seizures on the development of kindling in Wistar rats. METHODS: Three groups of adult male Wistar rats under anesthesia were implanted with bilateral cortical recording electrodes for the GBL group (GBL) and/or bipolar stimulation electrodes into the right basolateral amygdala for the Kindling group (KI) alone and Kindling plus GBL group (GBL+KI). Rats in the KI and GBL+KI groups were stimulated twice daily at the afterdischarge threshold until they reached Racine’s stage 5 seizure state. The animals in the GBL + group had an i.p injection of GBL 20 minutes before each electrical stimulation, and the effects of GBL-induced seizures on the development of kindling were investigated. The animals in the GBL group were injected GBL twice daily i.p. for 15 days without receiving any electrical stimulation. RESULTS: The KI animals reached stage 5 seizure stage at 12th stimulations, whereas the GBL+KI rats reached at 27th stimulations. The mean numbers of stimulations needed for the development of the first stage 3, 4, or 5 generalized seizures were significantly higher in the GBL+KI group than the KI group. CONCLUSION: The resistance to amygdala kindling in the GBL model can be modulated by the absence seizure mechanism alone, without the intervention of an abnormal genetic background.
Collapse
|
25
|
Glaba P, Latka M, Krause MJ, Kuryło M, Jernajczyk W, Walas W, West BJ. Changes in Interictal Pretreatment and Posttreatment EEG in Childhood Absence Epilepsy. Front Neurosci 2020; 14:196. [PMID: 32231515 PMCID: PMC7082231 DOI: 10.3389/fnins.2020.00196] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 02/24/2020] [Indexed: 01/09/2023] Open
Abstract
Spike and wave discharges (SWDs) are a characteristic manifestation of childhood absence epilepsy (CAE). It has long been believed that they unpredictably emerge from otherwise almost normal interictal EEG. Herein, we demonstrate that pretreatment closed-eyes theta and beta EEG wavelet powers of CAE patients (20 girls and 10 boys, mean age 7.4 ± 1.9 years) are much higher than those of age-matched healthy controls at multiple sites of the 10-20 system. For example, at the C4 site, we observed a 100 and 63% increase in power of theta and beta rhythms, respectively. We were able to compare the baseline and posttreatment wavelet power in 16 patients. Pharmacotherapy brought about a statistically significant decrease in delta and theta wavelet power in all the channels, e.g., for C4 the reduction was equal to 45% (delta) and 63% (theta). The less pronounced attenuation of posttreatment beta waves was observed in 13 channels (36% at C4 site). The beta and theta wavelet power were positively correlated with the percentage of time in seizure (defined as the ratio of the duration of all absences which patients experienced to the duration of recording) for majority of channels. We hypothesize that the increased theta and beta powers result from cortical hyperexcitability and propensity for epileptic spike generation, respectively. We argue that the distinct features of CAE wavelet power spectrum may be used to define an EEG biomarker which could be used for diagnosis and monitoring of patients.
Collapse
Affiliation(s)
- Pawel Glaba
- Department of Biomedical Engineering, Wrocław University of Science and Technology, Wrocław, Poland
| | - Miroslaw Latka
- Department of Biomedical Engineering, Wrocław University of Science and Technology, Wrocław, Poland
| | | | - Marta Kuryło
- Department of Pediatric Neurology, T. Marciniak Hospital, Wrocław, Poland
| | - Wojciech Jernajczyk
- Clinical Neurophysiology, Institute of Psychiatry and Neurology, Warszawa, Poland
| | - Wojciech Walas
- Neonatal and Pediatric Intensive Care Unit, University Hospital in Opole, Opole, Poland
| | - Bruce J West
- Mathematics and Information Science Directorate, Army Research Office, Durham, NC, United States
| |
Collapse
|
26
|
Çavdar S, Kuvvet Y, Sur-Erdem I, Özgür M, Onat F. Relationships between astrocytes and absence epilepsy in rat: An experimental study. Neurosci Lett 2019; 712:134518. [DOI: 10.1016/j.neulet.2019.134518] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/13/2019] [Accepted: 09/23/2019] [Indexed: 01/06/2023]
|
27
|
Young JC, Vaughan DN, Paolini AG, Jackson GD. Electrical stimulation of the piriform cortex for the treatment of epilepsy: A review of the supporting evidence. Epilepsy Behav 2018; 88:152-161. [PMID: 30269034 DOI: 10.1016/j.yebeh.2018.09.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 09/04/2018] [Accepted: 09/09/2018] [Indexed: 10/28/2022]
Abstract
In this review, we consider how the piriform cortex is engaged in both focal and generalized epilepsy networks and postulate the various neural pathways that can be effectively neuromodulated by stimulation at this site. This highlights the common involvement of the piriform cortex in epilepsy. We address both current and future preclinical studies of deep brain stimulation (DBS) of the piriform cortex, with attention to the critical features of these trials that will enable them to be of greatest utility in informing clinical translation. Although recent DBS trials have utilized thalamic targets, electrical stimulation of the piriform cortex may also be a useful intervention for people with epilepsy. However, more work is required to develop a solid foundation for this approach before considering human trials.
Collapse
Affiliation(s)
- James C Young
- The Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, 245 Burgundy Street, Heidelberg, Victoria 3084, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, 30 Royal Parade, Parkville, Victoria 3052, Australia.
| | - David N Vaughan
- The Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, 245 Burgundy Street, Heidelberg, Victoria 3084, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, 30 Royal Parade, Parkville, Victoria 3052, Australia; Department of Neurology, Austin Health, Melbourne, 145 Studley Road, Heidelberg, Victoria 3084, Australia
| | - Antonio G Paolini
- The Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, 245 Burgundy Street, Heidelberg, Victoria 3084, Australia; ISN Psychology - Institute for Social Neuroscience, Melbourne, Level 6/10 Martin Street, Heidelberg, Victoria 3084, Australia; School of Psychology and Public Health, La Trobe University, Melbourne, Plenty Road and Kingsbury Drive, Bundoora, VIC 3068, Australia
| | - Graeme D Jackson
- The Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, 245 Burgundy Street, Heidelberg, Victoria 3084, Australia; Florey Department of Neuroscience and Mental Health, The University of Melbourne, Melbourne, 30 Royal Parade, Parkville, Victoria 3052, Australia; Department of Neurology, Austin Health, Melbourne, 145 Studley Road, Heidelberg, Victoria 3084, Australia
| |
Collapse
|
28
|
Santos VR, Kobayashi I, Hammack R, Danko G, Forcelli PA. Impact of strain, sex, and estrous cycle on gamma butyrolactone-evoked absence seizures in rats. Epilepsy Res 2018; 147:62-70. [PMID: 30261353 PMCID: PMC6226012 DOI: 10.1016/j.eplepsyres.2018.09.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 09/03/2018] [Accepted: 09/15/2018] [Indexed: 12/19/2022]
Abstract
Childhood absence epilepsy (CAE) is the most common pediatric epilepsy syndrome and is characterized by typical absence seizures (AS). AS are non-convulsive epileptic seizures characterized by a sudden loss of awareness and bilaterally generalized synchronous 2.5-4 Hz spike and slow-wave discharges (SWD). Gamma butyrolactone (GBL) is an acute pharmacological model of AS and induces bilaterally synchronous SWDs and behavioral arrest. Despite the long use of this model, little is known about its strain and sex-dependent features. We compared the dose-response profile of GBL-evoked SWDs in three rat strains (Long Evans, Sprague-Dawley, and Wistar), and examined the modulatory effects of estrous cycle on SWDs in female Wistar rats. We evaluated the number of seizures, the cumulative time seizing, and the average seizure duration as a function of dose, strain, and sex/estrous phase. Long Evans rats displayed the greatest sensitivity to GBL, followed by Wistar rats, and then by Sprague-Dawley rats. GBL-evoked SWDs were modulated by estrous cycle in female rats, with the lowest sensitivity to GBL occurring during metestrus. Wistar rats showed the greatest variability as a function of dose, and the least variability within dose; these features make this strain desirable for interventional studies. Moreover, our finding that the SWD response to GBL differs as a function of estrous cycle underscores the importance of cycle monitoring in studies examining female animals using this model. Together, these strain and sex-dependent findings provide guidance for future studies.
Collapse
Affiliation(s)
- Victor R Santos
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, United States
| | - Ihori Kobayashi
- Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, United States
| | - Robert Hammack
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, United States
| | - Gregory Danko
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, United States
| | - Patrick A Forcelli
- Department of Pharmacology & Physiology, Georgetown University School of Medicine, United States; Department of Neuroscience, Georgetown University School of Medicine, United States; Interdisciplinary Program in Neuroscience, Georgetown University School of Medicine, United States.
| |
Collapse
|
29
|
Mi DJ, Dixit S, Warner TA, Kennard JA, Scharf DA, Kessler ES, Moore LM, Consoli DC, Bown CW, Eugene AJ, Kang JQ, Harrison FE. Altered glutamate clearance in ascorbate deficient mice increases seizure susceptibility and contributes to cognitive impairment in APP/PSEN1 mice. Neurobiol Aging 2018; 71:241-254. [PMID: 30172223 DOI: 10.1016/j.neurobiolaging.2018.08.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 12/24/2022]
Abstract
Ascorbate (vitamin C) is critical as a first line of defense antioxidant within the brain, and specifically within the synapse. Ascorbate is released by astrocytes during glutamate clearance and disruption of this exchange mechanism may be critical in mediating glutamate toxicity within the synapse. This is likely even more critical in neurodegenerative disorders with associated excitotoxicity and seizures, in particular Alzheimer's disease, in which ascorbate levels are often low. Using Gulo-/- mice that are dependent on dietary ascorbate, we established that low brain ascorbate increased sensitivity to kainic acid as measured via behavioral observations, electroencephalography (EEG) measurements, and altered regulation of several glutamatergic system genes. Kainic acid-induced immobility was improved in wild-type mice following treatment with ceftriaxone, which upregulates glutamate transporter GLT-1. The same effect was not observed in ascorbate-deficient mice in which sufficient ascorbate is not available for release. A single, mild seizure event was sufficient to disrupt performance in the water maze in low-ascorbate mice and in APPSWE/PSEN1dE9 mice. Together, the data support the critical role of brain ascorbate in maintaining protection during glutamatergic hyperexcitation events, including seizures. The study further supports a role for mild, subclinical seizures in cognitive decline in Alzheimer's disease.
Collapse
Affiliation(s)
- Deborah J Mi
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Shilpy Dixit
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Timothy A Warner
- Division of Neurology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John A Kennard
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Daniel A Scharf
- Undergraduate Program in Neuroscience, Vanderbilt University, Nashville, TN, USA
| | - Eric S Kessler
- Undergraduate Program in Neuroscience, Vanderbilt University, Nashville, TN, USA
| | - Lisa M Moore
- Undergraduate Program in Neuroscience, Vanderbilt University, Nashville, TN, USA
| | - David C Consoli
- Interdisciplinary Graduate Program, Vanderbilt University, Nashville, TN, USA
| | - Corey W Bown
- Interdisciplinary Graduate Program, Vanderbilt University, Nashville, TN, USA
| | - Angeline J Eugene
- Undergraduate Program in Neuroscience, Vanderbilt University, Nashville, TN, USA
| | - Jing-Qiong Kang
- Division of Neurology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Fiona E Harrison
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
| |
Collapse
|
30
|
Cain SM, Tyson JR, Choi H, Ko R, Lin PJC, LeDue JM, Powell KL, Bernier L, Rungta RL, Yang Y, Cullis PR, O'Brien TJ, MacVicar BA, Snutch TP. Ca V 3.2 drives sustained burst-firing, which is critical for absence seizure propagation in reticular thalamic neurons. Epilepsia 2018; 59:778-791. [PMID: 29468672 PMCID: PMC5900875 DOI: 10.1111/epi.14018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2018] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Genetic alterations have been identified in the CACNA1H gene, encoding the CaV 3.2 T-type calcium channel in patients with absence epilepsy, yet the precise mechanisms relating to seizure propagation and spike-wave-discharge (SWD) pacemaking remain unknown. Neurons of the thalamic reticular nucleus (TRN) express high levels of CaV 3.2 calcium channels, and we investigated whether a gain-of-function mutation in the Cacna1h gene in Genetic Absence Epilepsy Rats from Strasbourg (GAERS) contributes to seizure propagation and pacemaking in the TRN. METHODS Pathophysiological contributions of CaV 3.2 calcium channels to burst firing and absence seizures were assessed in vitro using acute brain slice electrophysiology and quantitative real-time polymerase chain reaction (PCR) and in vivo using free-moving electrocorticography recordings. RESULTS TRN neurons from GAERS display sustained oscillatory burst-firing that is both age- and frequency-dependent, occurring only in the frequencies overlapping with GAERS SWDs and correlating with the expression of a CaV 3.2 mutation-sensitive splice variant. In vivo knock-down of CaV 3.2 using direct thalamic injection of lipid nanoparticles containing CaV 3.2 dicer small interfering (Dsi) RNA normalized TRN burst-firing, and in free-moving GAERS significantly shortened seizures. SIGNIFICANCE This supports a role for TRN CaV 3.2 T-type channels in propagating thalamocortical network seizures and setting the pacemaking frequency of SWDs.
Collapse
Affiliation(s)
- Stuart M. Cain
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - John R. Tyson
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Hyun‐Beom Choi
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Rebecca Ko
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Paulo J. C. Lin
- Life Sciences InstituteUniversity of British ColumbiaVancouverBCCanada
| | - Jeffrey M. LeDue
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Kim L. Powell
- The Department of NeuroscienceCentral Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Louis‐Philippe Bernier
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Ravi L. Rungta
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Yi Yang
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Pieter R. Cullis
- Life Sciences InstituteUniversity of British ColumbiaVancouverBCCanada
| | - Terence J. O'Brien
- The Department of NeuroscienceCentral Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Brian A. MacVicar
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Terrance P. Snutch
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| |
Collapse
|
31
|
Sahin D, Yilmaz CU, Orhan N, Arican N, Kaya M, Gürses C, Ates N, Ahishali B. Changes in electroencephalographic characteristics and blood-brain barrier permeability in WAG/Rij rats with cortical dysplasia. Epilepsy Behav 2017; 67:70-76. [PMID: 28088684 DOI: 10.1016/j.yebeh.2016.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 10/06/2016] [Accepted: 11/03/2016] [Indexed: 12/13/2022]
Abstract
PURPOSE This study investigated the effects of cortical dysplasia (CD) on electrophysiology and blood-brain barrier (BBB) permeability in WAG/Rij rats with genetic absence epilepsy. METHODS Pregnant WAG/Rij rats were exposed to 145cGy of gamma-irradiation on embryonic day 17 to induce CD. An electroencephalogram was recorded from cortices subdurally in the offspring of the pregnant animals. Horseradish peroxidase (HRP) was used as determinant of BBB permeability. RESULTS A massive tissue loss in the cerebral cortex was seen in WAG/Rij rats with CD (p<0.05). There was a significant decrease in the number and duration of spike-and-wave discharges (SWDs) and an increase in the frequency of SWDs in the WAG/Rij rats with CD when compared with the properties of SWDs in intact WAG/Rij rats (p<0.01). Ultrastructurally, the accumulation of HRP reaction products in the cerebral cortex and thalamus of WAG/Rij rats was significantly higher than that of control values (p<0.01). The accumulation of HRP reaction products in the cerebral cortex and thalamus regions of WAG/Rij rats with CD increased and was higher than that of the control and WAG/Rij animals (p<0.01). CONCLUSION In our study, we showed that number and duration of SWDs decreased and SWD frequency increased in WAG/Rij rats with CD, suggesting a shift in seizure pattern. The association of these alterations with significant loss of cortical thickness and increased BBB permeability to HRP tracer may represent a causal relation of the EEG abnormalities with cerebral structural changes in these animals.
Collapse
Affiliation(s)
- Deniz Sahin
- Department of Physiology, Medical Faculty of Kocaeli University, Kocaeli, Turkey
| | - Canan Ugur Yilmaz
- Department of Laboratory Animals Science, Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Nurcan Orhan
- Department of Neuroscience, Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Nadir Arican
- Department of Forensic Medicine, Istanbul Faculty of Medicine, Istanbul University, Turkey
| | - Mehmet Kaya
- Koç University School of Medicine, Department of Physiology, Rumelifeneri Yolu, Sarıyer, 34450 Istanbul, Turkey.
| | - Candan Gürses
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Turkey
| | - Nurbay Ates
- Department of Physiology, Medical Faculty of Kocaeli University, Kocaeli, Turkey
| | - Bulent Ahishali
- Department of Histology and Embryology, Istanbul Faculty of Medicine, Istanbul University, Turkey
| |
Collapse
|
32
|
Bastianini S, Lo Martire V, Berteotti C, Silvani A, Ohtsu H, Lin JS, Zoccoli G. High-amplitude theta wave bursts characterizing narcoleptic mice and patients are also produced by histamine deficiency in mice. J Sleep Res 2016; 25:591-595. [DOI: 10.1111/jsr.12404] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 02/13/2016] [Indexed: 11/28/2022]
Affiliation(s)
- Stefano Bastianini
- Laboratory of Physiological Regulations in Sleeping Mice (PRISM); Department of Biomedical and Neuromotor Sciences; University of Bologna; Bologna Italy
| | - Viviana Lo Martire
- Laboratory of Physiological Regulations in Sleeping Mice (PRISM); Department of Biomedical and Neuromotor Sciences; University of Bologna; Bologna Italy
| | - Chiara Berteotti
- Laboratory of Physiological Regulations in Sleeping Mice (PRISM); Department of Biomedical and Neuromotor Sciences; University of Bologna; Bologna Italy
| | - Alessandro Silvani
- Laboratory of Physiological Regulations in Sleeping Mice (PRISM); Department of Biomedical and Neuromotor Sciences; University of Bologna; Bologna Italy
| | - Hiroshi Ohtsu
- Applied Quantum Medical Engineering; Graduate School of Engineering; Tohoku University; Sendai Japan
| | - Jian-Sheng Lin
- Physiologie intégrée du système d'éveil; Centre de recherche en neurosciences de Lyon; INSERM U1028-CNRS UMR 5292 Faculté de Médecine; Université Claude Bernard; Lyon France
| | - Giovanna Zoccoli
- Laboratory of Physiological Regulations in Sleeping Mice (PRISM); Department of Biomedical and Neuromotor Sciences; University of Bologna; Bologna Italy
| |
Collapse
|
33
|
Arain F, Zhou C, Ding L, Zaidi S, Gallagher MJ. The developmental evolution of the seizure phenotype and cortical inhibition in mouse models of juvenile myoclonic epilepsy. Neurobiol Dis 2015; 82:164-175. [PMID: 26054439 DOI: 10.1016/j.nbd.2015.05.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 05/13/2015] [Accepted: 05/27/2015] [Indexed: 11/20/2022] Open
Abstract
The GABA(A) receptor (GABA(A)R) α1 subunit mutation, A322D, causes autosomal dominant juvenile myoclonic epilepsy (JME). Previous in vitro studies demonstrated that A322D elicits α1(A322D) protein degradation and that the residual mutant protein causes a dominant-negative effect on wild type GABA(A)Rs. Here, we determined the effects of heterozygous A322D knockin (Het(α1)AD) and deletion (Het(α1)KO) on seizures, GABA(A)R expression, and motor cortex (M1) miniature inhibitory postsynaptic currents (mIPSCs) at two developmental time-points, P35 and P120. Both Het(α1)AD and Het(α1)KO mice experience absence seizures at P35 that persist at P120, but have substantially more frequent spontaneous and evoked polyspike wave discharges and myoclonic seizures at P120. Both mutant mice have increased total and synaptic α3 subunit expression at both time-points and decreased α1 subunit expression at P35, but not P120. There are proportional reductions in α3, β2, and γ2 subunit expression between P35 and P120 in wild type and mutant mice. In M1, mutants have decreased mIPSC peak amplitudes and prolonged decay constants compared with wild type, and the Het(α1)AD mice have reduced mIPSC frequency and smaller amplitudes than Het(α1)KO mice. Wild type and mutants exhibit proportional increases in mIPSC amplitudes between P35 and P120. We conclude that Het(α1)KO and Het(α1)AD mice model the JME subsyndrome, childhood absence epilepsy persisting and evolving into JME. Both mutants alter GABA(A)R composition and motor cortex physiology in a manner expected to increase neuronal synchrony and excitability to produce seizures. However, developmental changes in M1 GABA(A)Rs do not explain the worsened phenotype at P120 in mutant mice.
Collapse
Affiliation(s)
- Fazal Arain
- Department of Neurology, Vanderbilt University, Nashville, TN 37232-8552 USA
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University, Nashville, TN 37232-8552 USA
| | - Li Ding
- Department of Neurology, Vanderbilt University, Nashville, TN 37232-8552 USA
| | - Sahar Zaidi
- Department of Neurology, Vanderbilt University, Nashville, TN 37232-8552 USA
| | - Martin J Gallagher
- Department of Neurology, Vanderbilt University, Nashville, TN 37232-8552 USA.
| |
Collapse
|
34
|
Lüttjohann A, van Luijtelaar G. Dynamics of networks during absence seizure's on- and offset in rodents and man. Front Physiol 2015; 6:16. [PMID: 25698972 PMCID: PMC4318340 DOI: 10.3389/fphys.2015.00016] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/11/2015] [Indexed: 11/13/2022] Open
Abstract
Network mechanisms relevant for the generation, maintenance and termination of spike-wave discharges (SWD), the neurophysiological hallmark of absence epilepsy, are still enigmatic and widely discussed. Within the last years, however, improvements in signal analytical techniques, applied to both animal and human fMRI, EEG, MEG, and ECoG data, greatly increased our understanding and challenged several, dogmatic concepts of SWD. This review will summarize these recent data, demonstrating that SWD are not primary generalized, are not sudden and unpredictable events. It will disentangle different functional contributions of structures within the cortico-thalamo-cortical system, relevant for the generation, generalization, maintenance, and termination of SWD and will present a new “network based” scenario for these oscillations. Similarities and differences between rodent and human data are presented demonstrating that in both species a local cortical onset zone of SWD exists, although with different locations; that in both some forms of cortical and thalamic precursor activity can be found, and that SWD occur through repetitive cyclic activity between cortex and thalamus. The focal onset zone in human data could differ between patients with varying spatial and temporal dynamics; in rats the latter is still poorly investigated.
Collapse
Affiliation(s)
- Annika Lüttjohann
- Donders Centre for Cognition, Donders Instiute for Brain, Cognition and Behaviour, Radboud University Nijmegen Nijmegen, Netherlands ; Institute of Physiology I, Westfälische Wilhelms-University Münster Münster, Germany
| | - Gilles van Luijtelaar
- Donders Centre for Cognition, Donders Instiute for Brain, Cognition and Behaviour, Radboud University Nijmegen Nijmegen, Netherlands
| |
Collapse
|
35
|
Richard CD, Tanenbaum A, Audit B, Arneodo A, Khalil A, Frankel WN. SWDreader: a wavelet-based algorithm using spectral phase to characterize spike-wave morphological variation in genetic models of absence epilepsy. J Neurosci Methods 2014; 242:127-40. [PMID: 25549550 DOI: 10.1016/j.jneumeth.2014.12.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 12/17/2014] [Accepted: 12/19/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND Spike-wave discharges (SWD) found in neuroelectrical recordings are pathognomonic to absence epilepsy. The characteristic spike-wave morphology of the spike-wave complex (SWC) constituents of SWDs can be mathematically described by a subset of possible spectral power and phase values. Morlet wavelet transform (MWT) generates time-frequency representations well-suited to identifying this SWC-associated subset. NEW METHOD MWT decompositions of SWDs reveal spectral power concentrated at harmonic frequencies. The phase relationships underlying SWC morphology were identified by calculating the differences between phase values at SWD fundamental frequency from the 2nd, 3rd, and 4th harmonics, then using the three phase differences as coordinates to generate a density distribution in a {360°×360°×360°} phase difference space. Strain-specific density distributions were generated from SWDs of mice carrying the Gria4, Gabrg2, or Scn8a mutations to determine whether SWC morphological variants reliably mapped to the same regions of the distribution, and if distribution values could be used to detect SWD. COMPARISON WITH EXISTING METHODS To the best of our knowledge, this algorithm is the first to employ spectral phase to quantify SWC morphology, making it possible to computationally distinguish SWC morphological subtypes and detect SWDs. RESULTS/CONCLUSIONS Proof-of-concept testing of the SWDfinder algorithm shows: (1) a major pattern of variation in SWC morphology maps to one axis of the phase difference distribution, (2) variability between the strain-specific distributions reflects differences in the proportions of SWC subtypes generated during SWD, and (3) regularities in the spectral power and phase profiles of SWCs can be used to detect waveforms possessing SWC-like morphology.
Collapse
Affiliation(s)
- C D Richard
- The Jackson Laboratory, Bar Harbor, ME 04609 USA; Graduate School for Biomedical Sciences and Engineering, University of Maine, Orono, ME 04469 USA.
| | - A Tanenbaum
- Department of Neurology, School of Medicine, Washington University, St. Louis, MO 63130 USA; CompuMAINE Lab, Department of Mathematics, University of Maine, Orono, ME 04469 USA
| | - B Audit
- Laboratoire de Physique, CNRS UMR 5672, Université de Lyon, École Normale Supérieure de Lyon, F-69007 Lyon, France
| | - A Arneodo
- Laboratoire de Physique, CNRS UMR 5672, Université de Lyon, École Normale Supérieure de Lyon, F-69007 Lyon, France
| | - A Khalil
- The Jackson Laboratory, Bar Harbor, ME 04609 USA; Graduate School for Biomedical Sciences and Engineering, University of Maine, Orono, ME 04469 USA; CompuMAINE Lab, Department of Mathematics, University of Maine, Orono, ME 04469 USA
| | - W N Frankel
- The Jackson Laboratory, Bar Harbor, ME 04609 USA; Graduate School for Biomedical Sciences and Engineering, University of Maine, Orono, ME 04469 USA; Tufts University School of Medicine, Sackler School, Boston, MA 02111 USA
| |
Collapse
|
36
|
Low brain ascorbic acid increases susceptibility to seizures in mouse models of decreased brain ascorbic acid transport and Alzheimer's disease. Epilepsy Res 2014; 110:20-5. [PMID: 25616451 DOI: 10.1016/j.eplepsyres.2014.11.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 11/12/2014] [Accepted: 11/17/2014] [Indexed: 11/23/2022]
Abstract
Seizures are a known co-occurring symptom of Alzheimer's disease, and they can accelerate cognitive and neuropathological dysfunction. Sub-optimal vitamin C (ascorbic acid) deficiency, that is low levels that do not lead the sufferer to present with clinical signs of scurvy (e.g. lethargy, hemorrhage, hyperkeratosis), are easily obtainable with insufficient dietary intake, and may contribute to the oxidative stress environment of both Alzheimer's disease and epilepsy. The purpose of this study was to test whether mice that have diminished brain ascorbic acid in addition to carrying human Alzheimer's disease mutations in the amyloid precursor protein (APP) and presenilin 1 (PSEN1) genes, had altered electrical activity in the brain (electroencephalography; EEG), and were more susceptible to pharmacologically induced seizures. Brain ascorbic acid was decreased in APP/PSEN1 mice by crossing them with sodium vitamin C transporter 2 (SVCT2) heterozygous knockout mice. These mice have an approximately 30% decrease in brain ascorbic acid due to lower levels of SVCT2 that supplies the brain with ASC. SVCT2+/-APP/PSEN1 mice had decreased ascorbic acid and increased oxidative stress in brain, increased mortality, faster seizure onset latency following treatment with kainic acid (10 mg/kg i.p.), and more ictal events following pentylenetetrazol (50 mg/kg i.p.) treatment. Furthermore, we report the entirely novel phenomenon that ascorbic acid deficiency alone increased the severity of kainic acid- and pentylenetetrazol-induced seizures. These data suggest that avoiding ascorbic acid deficiency may be particularly important in populations at increased risk for epilepsy and seizures, such as Alzheimer's disease.
Collapse
|
37
|
Serikawa T, Mashimo T, Kuramoro T, Voigt B, Ohno Y, Sasa M. Advances on genetic rat models of epilepsy. Exp Anim 2014; 64:1-7. [PMID: 25312505 PMCID: PMC4329510 DOI: 10.1538/expanim.14-0066] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Considering the suitability of laboratory rats in epilepsy research, we and other groups
have been developing genetic models of epilepsy in this species. After epileptic rats or
seizure-susceptible rats were sporadically found in outbred stocks, the epileptic traits
were usually genetically-fixed by selective breeding. So far, the absence seizure models
GAERS and WAG/Rij, audiogenic seizure models GEPR-3 and GEPR-9, generalized tonic-clonic
seizure models IER, NER and WER, and Canavan-disease related epileptic models TRM and SER
have been established. Dissection of the genetic bases including causative genes in these
epileptic rat models would be a significant step toward understanding epileptogenesis.
N-ethyl-N-nitrosourea (ENU) mutagenesis provides a systematic approach which allowed us to
develop two novel epileptic rat models: heat-induced seizure susceptible (Hiss) rats with
an Scn1a missense mutation and autosomal dominant lateral temporal epilepsy (ADLTE) model
rats with an Lgi1 missense mutation. In addition, we have established episodic ataxia type
1 (EA1) model rats with a Kcna1 missense mutation derived from the ENU-induced rat mutant
stock, and identified a Cacna1a missense mutation in a N-Methyl-N-nitrosourea
(MNU)-induced mutant rat strain GRY, resulting in the discovery of episodic ataxia type 2
(EA2) model rats. Thus, epileptic rat models have been established on the two paths:
‘phenotype to gene’ and ‘gene to phenotype’. In the near future, development of novel
epileptic rat models will be extensively promoted by the use of sophisticated genome
editing technologies.
Collapse
Affiliation(s)
- Tadao Serikawa
- Graduate School of Medicine, Kyoto University, Sakyo-ku 606-8501; Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki 569-1094, Japan
| | | | | | | | | | | |
Collapse
|
38
|
van Luijtelaar G, Onat FY, Gallagher MJ. Animal models of absence epilepsies: what do they model and do sex and sex hormones matter? Neurobiol Dis 2014; 72 Pt B:167-79. [PMID: 25132554 DOI: 10.1016/j.nbd.2014.08.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 08/05/2014] [Accepted: 08/07/2014] [Indexed: 11/28/2022] Open
Abstract
While epidemiological data suggest a female prevalence in human childhood- and adolescence-onset typical absence epilepsy syndromes, the sex difference is less clear in adult-onset syndromes. In addition, although there are more females than males diagnosed with typical absence epilepsy syndromes, there is a paucity of studies on sex differences in seizure frequency and semiology in patients diagnosed with any absence epilepsy syndrome. Moreover, it is unknown if there are sex differences in the prevalence or expression of atypical absence epilepsy syndromes. Surprisingly, most studies of animal models of absence epilepsy either did not investigate sex differences, or failed to find sex-dependent effects. However, various rodent models for atypical syndromes such as the AY9944 model (prepubertal females show a higher incidence than prepubertal males), BN model (also with a higher prevalence in males) and the Gabra1 deletion mouse in the C57BL/6J strain offer unique possibilities for the investigation of the mechanisms involved in sex differences. Although the mechanistic bases for the sex differences in humans or these three models are not yet known, studies of the effects of sex hormones on seizures have offered some possibilities. The sex hormones progesterone, estradiol and testosterone exert diametrically opposite effects in genetic absence epilepsy and pharmacologically-evoked convulsive types of epilepsy models. In addition, acute pharmacological effects of progesterone on absence seizures during proestrus are opposite to those seen during pregnancy. 17β-Estradiol has anti-absence seizure effects, but it is only active in atypical absence models. It is speculated that the pro-absence action of progesterone, and perhaps also the delayed pro-absence action of testosterone, are mediated through the neurosteroid allopregnanolone and its structural and functional homolog, androstanediol. These two steroids increase extrasynaptic thalamic tonic GABAergic inhibition by selectively targeting neurosteroid-selective subunits of GABAA receptors (GABAARs). Neurosteroids also modulate the expression of GABAAR containing the γ2, α4, and δ subunits. It is hypothesized that differences in subunit expression during pregnancy and ovarian cycle contribute to the opposite effects of progesterone in these two hormonal states.
Collapse
Affiliation(s)
- Gilles van Luijtelaar
- Donders Centre of Cognition, Radboud University Nijmegen, Nijmegen, The Netherlands.
| | - Filiz Yilmaz Onat
- Department of Pharmacology, School of Medicine, Marmara University, Istanbul, Turkey
| | | |
Collapse
|
39
|
Kovács Z, Dobolyi Á, Juhász G, Kékesi KA. Lipopolysaccharide induced increase in seizure activity in two animal models of absence epilepsy WAG/Rij and GAERS rats and Long Evans rats. Brain Res Bull 2014; 104:7-18. [DOI: 10.1016/j.brainresbull.2014.03.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 03/20/2014] [Accepted: 03/24/2014] [Indexed: 02/04/2023]
|
40
|
Kandratavicius L, Balista PA, Lopes-Aguiar C, Ruggiero RN, Umeoka EH, Garcia-Cairasco N, Bueno-Junior LS, Leite JP. Animal models of epilepsy: use and limitations. Neuropsychiatr Dis Treat 2014; 10:1693-705. [PMID: 25228809 PMCID: PMC4164293 DOI: 10.2147/ndt.s50371] [Citation(s) in RCA: 293] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Epilepsy is a chronic neurological condition characterized by recurrent seizures that affects millions of people worldwide. Comprehension of the complex mechanisms underlying epileptogenesis and seizure generation in temporal lobe epilepsy and other forms of epilepsy cannot be fully acquired in clinical studies with humans. As a result, the use of appropriate animal models is essential. Some of these models replicate the natural history of symptomatic focal epilepsy with an initial epileptogenic insult, which is followed by an apparent latent period and by a subsequent period of chronic spontaneous seizures. Seizures are a combination of electrical and behavioral events that are able to induce chemical, molecular, and anatomic alterations. In this review, we summarize the most frequently used models of chronic epilepsy and models of acute seizures induced by chemoconvulsants, traumatic brain injury, and electrical or sound stimuli. Genetic models of absence seizures and models of seizures and status epilepticus in the immature brain were also examined. Major uses and limitations were highlighted, and neuropathological, behavioral, and neurophysiological similarities and differences between the model and the human equivalent were considered. The quest for seizure mechanisms can provide insights into overall brain functions and consciousness, and animal models of epilepsy will continue to promote the progress of both epilepsy and neurophysiology research.
Collapse
Affiliation(s)
- Ludmyla Kandratavicius
- Department of Neurosciences and Behavior, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Priscila Alves Balista
- Department of Neurosciences and Behavior, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Cleiton Lopes-Aguiar
- Department of Neurosciences and Behavior, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Rafael Naime Ruggiero
- Department of Neurosciences and Behavior, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Eduardo Henrique Umeoka
- Department of Physiology, Ribeirao Preto School of Medicine, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Norberto Garcia-Cairasco
- Department of Physiology, Ribeirao Preto School of Medicine, University of Sao Paulo, Ribeirao Preto, Brazil
| | | | - Joao Pereira Leite
- Department of Neurosciences and Behavior, University of Sao Paulo, Ribeirao Preto, Brazil
| |
Collapse
|
41
|
van Luijtelaar G, Mishra AM, Edelbroek P, Coman D, Frankenmolen N, Schaapsmeerders P, Covolato G, Danielson N, Niermann H, Janeczko K, Kiemeneij A, Burinov J, Bashyal C, Coquillette M, Lüttjohann A, Hyder F, Blumenfeld H, van Rijn CM. Anti-epileptogenesis: Electrophysiology, diffusion tensor imaging and behavior in a genetic absence model. Neurobiol Dis 2013; 60:126-38. [PMID: 23978468 DOI: 10.1016/j.nbd.2013.08.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 08/14/2013] [Indexed: 11/18/2022] Open
Abstract
The beneficial effects of chronic and early pharmacological treatment with ethosuximide on epileptogenesis were studied in a genetic absence epilepsy model comorbid for depression. It was also investigated whether there is a critical treatment period and treatment length. Cortical excitability in the form of electrical evoked potentials, but also to cortico-thalamo-cortical network activity (spike-wave discharges, SWD and afterdischarges), white matter changes representing extra cortico-thalamic functions and depressive-like behavior were investigated. WAG/Rij rats received either ethosuximide for 2 months (post natal months 2-3 or 4-5), or ethosuximide for 4 months (2-5) in their drinking water, while control rats drank plain water. EEG measurements were made during treatment, and 6 days and 2 months post treatment. Behavioral test were also done 6 days post treatment. DTI was performed ex vivo post treatment. SWD were suppressed during treatment, and 6 days and 2 months post treatment in the 4 month treated group, as well as the duration of AD elicited by cortical electrical stimulation 6 days post treatment. Increased fractional anisotropy in corpus callosum and internal capsula on DTI was found, an increased P8 evoked potential amplitude and a decreased immobility in the forced swim test. Shorter treatments with ETX had no large effects on any parameter. Chronic ETX has widespread effects not only within but also outside the circuitry in which SWD are initiated and generated, including preventing epileptogenesis and reducing depressive-like symptoms. The treatment of patients before symptom onset might prevent many of the adverse consequences of chronic epilepsy.
Collapse
Affiliation(s)
- Gilles van Luijtelaar
- Donders Centre for Cognition, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Jones NC, O'Brien TJ. Stress, epilepsy, and psychiatric comorbidity: how can animal models inform the clinic? Epilepsy Behav 2013; 26:363-9. [PMID: 23099287 DOI: 10.1016/j.yebeh.2012.09.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 09/06/2012] [Indexed: 12/15/2022]
Abstract
Psychiatric complaints afflict many patients with epilepsy, and these contribute significantly to the impaired quality of life experienced by sufferers of this common group of neurological conditions. Psychiatric disorders in epilepsy patients are under-diagnosed and under-treated. Moreover, evidence suggests that the psychiatric disorders may act as risk factors for some types of epilepsy and exacerbate disease progression in established cases, promoting the case for a bidirectional relationship between epilepsy and psychopathology. While cause and effect relationships can be difficult to establish in human studies, appropriate animal models provide valuable tools with which to study the interactions between epilepsy and stress-related disorders. Indeed, many epilepsy models exhibit behavioral phenotypes which are reflective of psychiatric disorders, and, conversely, stressful environments appear to promote a vulnerability to developing epilepsy. This review summarizes this research area, exploring the behavioral phenotypes in animal models of epilepsy and then examining the influence of stressful environments on susceptibility to seizures and epilepsy. The ultimate goal of this line of research is to be able to translate these findings to humans. Understanding the relationships between epilepsy and associated psychiatric disorders will facilitate effective treatment of mood disorders in epilepsy, inform about the pathophysiology of each individually, and potentially open up novel therapeutic disease-modifying strategies for patients with epilepsy.
Collapse
Affiliation(s)
- Nigel C Jones
- Department of Medicine (Royal Melbourne Hospital), Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia.
| | | |
Collapse
|
43
|
The involvement of limbic structures in typical and atypical absence epilepsy. Epilepsy Res 2013; 103:111-23. [DOI: 10.1016/j.eplepsyres.2012.08.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 08/15/2012] [Accepted: 08/22/2012] [Indexed: 11/21/2022]
|
44
|
T-type calcium channels in burst-firing, network synchrony, and epilepsy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:1572-8. [PMID: 22885138 DOI: 10.1016/j.bbamem.2012.07.028] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 07/23/2012] [Accepted: 07/25/2012] [Indexed: 11/23/2022]
Abstract
Low voltage-activated (LVA) T-type calcium channels are well regarded as a key mechanism underlying the generation of neuronal burst-firing. Their low threshold for activation combined with a rapid and transient calcium conductance generates low-threshold calcium potentials (LTCPs), upon the crest of which high frequency action potentials fire for a brief period. Experiments using simultaneous electroencephalography (EEG) and intracellular recordings demonstrate that neuronal burst-firing is a likely causative component in the generation of normal sleep patterns as well as some pathophysiological conditions, such as epileptic seizures. However, less is known as to how these neuronal bursts impact brain behavior, in particular network synchronization. In this review we summarize recent findings concerning the role of T-type calcium channels in burst-firing and discuss how they likely contribute to the generation of network synchrony. We further outline the function of burst-firing and network synchrony in terms of epileptic seizures. This article is part of a Special Issue entitled: Calcium channels.
Collapse
|
45
|
Arain FM, Boyd KL, Gallagher MJ. Decreased viability and absence-like epilepsy in mice lacking or deficient in the GABAA receptor α1 subunit. Epilepsia 2012; 53:e161-5. [PMID: 22812724 DOI: 10.1111/j.1528-1167.2012.03596.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Autosomal dominant mutations S326fs328X and A322D in the GABA(A) receptor α1 subunit are associated with human absence epilepsy and juvenile myoclonic epilepsy, respectively. Because these mutations substantially reduce α1 subunit protein expression in vitro, it was hypothesized that they produce epilepsy by causing α1 subunit haploinsufficiency. However, in a mixed background strain of mice, α1 subunit deletion does not reduce viability or cause visually apparent seizures; the effects of α1 subunit deletion on electroencephalography (EEG) waveforms were not investigated. Here, we determined the effects of α1 subunit loss on viability, EEG spike-wave discharges and seizures in congenic C57BL/6J and DBA/2J mice. Deletion of α1 subunit caused strain- and sex-dependent reductions in viability. Heterozygous mice experienced EEG discharges and absence-like seizures within both background strains, and exhibited a sex-dependent effect on the discharges and viability in the C57BL/6J strain. These findings suggest that α1 subunit haploinsufficiency can produce epilepsy and may be a major mechanism by which the S326fs328X and A322D mutations cause these epilepsy syndromes.
Collapse
Affiliation(s)
- Fazal M Arain
- Department of Neurology, Vanderbilt University, Nashville, Tennessee 37232-8552, USA
| | | | | |
Collapse
|
46
|
Huang HY, Hu SH, Chian CS, Chen SY, Lai HY, Chen YY. Self-assembling PVA-F127 thermosensitive nanocarriers with highly sensitive magnetically-triggered drug release for epilepsy therapy in vivo. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm00032f] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
47
|
Matos G, Tufik S, Scorza FA, Cavalheiro EA, Andersen ML. Sleep, epilepsy and translational research: What can we learn from the laboratory bench? Prog Neurobiol 2011; 95:396-405. [DOI: 10.1016/j.pneurobio.2011.09.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 08/19/2011] [Accepted: 09/18/2011] [Indexed: 12/20/2022]
|
48
|
Sarkisova K, van Luijtelaar G. The WAG/Rij strain: a genetic animal model of absence epilepsy with comorbidity of depression [corrected]. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:854-76. [PMID: 21093520 DOI: 10.1016/j.pnpbp.2010.11.010] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 09/28/2010] [Accepted: 11/09/2010] [Indexed: 01/02/2023]
Abstract
A great number of clinical observations show a relationship between epilepsy and depression. Idiopathic generalized epilepsy, including absence epilepsy, has a genetic basis. The review provides evidence that WAG/Rij rats can be regarded as a valid genetic animal model of absence epilepsy with comorbidity of depression. WAG/Rij rats, originally developed as an animal model of human absence epilepsy, share many EEG and behavioral characteristics resembling absence epilepsy in humans, including the similarity of action of various antiepileptic drugs. Behavioral studies indicate that WAG/Rij rats exhibit depression-like symptoms: decreased investigative activity in the open field test, increased immobility in the forced swimming test, and decreased sucrose consumption and preference (anhedonia). In addition, WAG/Rij rats adopt passive strategies in stressful situations, express some cognitive disturbances (reduced long-term memory), helplessness, and submissiveness, inability to make choice and overcome obstacles, which are typical for depressed patients. Elevated anxiety is not a characteristic (specific) feature of WAG/Rij rats; it is a characteristic for only a sub-strain of WAG/Rij rats susceptible to audiogenic seizures. Interestingly, WAG/Rij rats display a hyper-response to amphetamine similar to anhedonic depressed patients. WAG/Rij rats are sensitive only to chronic, but not acute, antidepressant treatments, suggesting that WAG/Rij rats fulfill a criterion of predictive validity for a putative animal model of depression. However, more and different antidepressant drugs still await evaluation. Depression-like behavioral symptoms in WAG/Rij rats are evident at baseline conditions, not exclusively after stress. Experiments with foot-shock stress do not point towards higher stress sensitivity at both behavioral and hormonal levels. However, freezing behavior (coping deficits) and blunted response of 5HT in the frontal cortex to uncontrollable sound stress, increased c-fos expression in the terminal regions of the meso-cortico-limbic brain systems and greater DA response of the mesolimbic system to forced swim stress suggest that WAG/Rij rats are vulnerable to some, but not to all types of stressors. We propose that genetic absence epileptic WAG/Rij rats have behavioral depression-like symptoms, are vulnerable to stress and might represent a model of chronic low-grade depression (dysthymia). Both 5HT and DAergic abnormalities detected in the brain of WAG/Rij rats are involved in modulation of vulnerability to stress and provocation of behavioral depression-like symptoms. The same neurotransmitter systems modulate SWDs as well. Recent studies suggest that the occurrence and repetition of absence seizures are a precipitant of depression-like behavior. Whether the neurochemical changes are primary to depression-like behavioral alterations remains to be determined. In conclusion, the WAG/Rij rats can be considered as a genetic animal model for absence epilepsy with comorbidity of dysthymia. This model can be used to investigate etiology, pathogenic mechanisms and treatment of a psychiatric comorbidity, such as depression in absence epilepsy, to reveal putative genes contributing to comorbid depressive disorder, and to screen novel psychotropic drugs with a selective and/or complex (dual) action on both pathologies.
Collapse
Affiliation(s)
- Karine Sarkisova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerov str. 5a, Moscow 117485, Russia.
| | | |
Collapse
|
49
|
Jones NC, O’Brien TJ, Powell KL. Morphometric changes and molecular mechanisms in rat models of idiopathic generalized epilepsy with absence seizures. Neurosci Lett 2011; 497:185-93. [DOI: 10.1016/j.neulet.2011.02.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 01/21/2011] [Accepted: 02/15/2011] [Indexed: 01/29/2023]
|
50
|
van Luijtelaar G, Sitnikova E, Littjohann A. On the origin and suddenness of absences in genetic absence models. Clin EEG Neurosci 2011; 42:83-97. [PMID: 21675598 DOI: 10.1177/155005941104200209] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The origin of spike-wave discharges (SWDs), typical for absences, has been debated for at least half a century. While most classical views adhere to a thalamic oscillatory machinery and an active role of the cortex in modifying normal oscillations into pathological SWDs, recent studies in genetic models such as WAG/Rij and GAERS rats have challenged this proposal. It seems now well established that SWDs originate from the deep layers of the somatosensory cortex, that the activity quickly spreads over the cortex and invades the thalamus. The reticular thalamic nucleus and other thalamic nuclei provide a resonance circuitry for the amplification, spreading and entrainment of the SWDs. Conclusive evidence has been found that the changed functionality of HCN1 channels is a causative factor for the changes in local excitability and age-dependent increase in SWD. Furthermore, upregulation of two subtypes of Na+ channels, reduction of GABAB and mGlu 2/3 receptors might also play a role in the local increased excitability in WAG/Rij rats. Signal analytical studies have also challenged the view that SWDs occur suddenly from a normal background EEG. SWDs are recruited cortical responses and they develop from increasing associations within and between cortical layers and subsequently subcortical regions, triggered by the simultaneous occurrence of theta and delta precursor activity in the cortex and thalamus in case both structures are in a favorable condition, and increased directional coupling between cortex and thalamus. It is hypothesized that the cortex is the driving force throughout the whole SWD and is also responsible for its end.
Collapse
Affiliation(s)
- Gilles van Luijtelaar
- Department of Biological Psychology, Donders Centre for Cognition, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen , Nijmegen, the Netherlands.
| | | | | |
Collapse
|