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Ilbay G, Balıkcı A, Köktürk S, Yılmaz MY, Ates N, Baydemır C, Balcı S. Neonatal Tactile Stimulation Downregulates Dendritic Spines in Layer V Pyramidal Neurons of the WAG/Rij Rat Somatosensory Cortex. Neural Plast 2022; 2022:7251460. [PMID: 35465396 PMCID: PMC9019463 DOI: 10.1155/2022/7251460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/28/2022] [Accepted: 03/25/2022] [Indexed: 11/18/2022] Open
Abstract
Objective The aim of our study is to examine the effects of neonatal tactile stimulations on the brain structures that previously defined as the focus of epilepsy in the Wistar-Albino-Glaxo from Rijswijk (WAG/Rij) rat brain with genetic absence epilepsy. Methods In the present research, morphology and density of dendritic spines were analyzed in layer V pyramidal neurons of the somatosensory cortex (SoCx) of WAG/Rij rats (nonstimulated control, tactile-stimulated, and maternal separated rats) and healthy Wistar (nonepileptic) rats. To achieve this, a Golgi-Cox method was used. Results Dendritic spine number in layer V of the SoCx has been detected significantly higher in adult WAG/Rij rats at postnatal day 150 in comparison to nonepileptic adult control Wistar rats (p < 0.001). Moreover, quantitative analyses of dendrite structure in adult WAG/Rij rats showed a decrease in dendrite spine density of pyramidal neurons of SoCx which occurred in early neonatal exposure to maternal separation (MS) and tactile stimulation (TS) (p < 0.001). Conclusions Our findings provide the first evidence that tactile stimulations during the early postnatal period have a long-term impact on dendrite structure in WAG/Rij rat's brain and demonstrate that neonatal tactile stimulation can regulate dendritic spines in layer V in pyramidal neurons of SoCx in epileptic brains.
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Affiliation(s)
- Gul Ilbay
- Department of Physiology, Kocaeli University, School of Medicine, Kocaeli, Turkey
| | - Aymen Balıkcı
- Department of Physiology, Kocaeli University, School of Medicine, Kocaeli, Turkey
| | - Sibel Köktürk
- Department of Histology and Embryology, Istanbul University, Istanbul Medical Faculty, Istanbul, Turkey
| | - Melda Yardımoglu Yılmaz
- Department of Histology and Embryology, Kocaeli University, School of Medicine, Kocaeli, Turkey
| | - Nurbay Ates
- Department of Physiology, Kocaeli University, School of Medicine, Kocaeli, Turkey
| | - Canan Baydemır
- Department of Biostatistics and Medical Informatics, Kocaeli University, School of Medicine, Kocaeli, Turkey
| | - Sibel Balcı
- Department of Biostatistics and Medical Informatics, Kocaeli University, School of Medicine, Kocaeli, Turkey
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Aygun H, Ayyildiz M, Agar E. Effects of vitamin D and paricalcitol on epileptogenesis and behavioral properties of WAG/Rij rats with absence epilepsy. Epilepsy Res 2019; 157:106208. [PMID: 31581040 DOI: 10.1016/j.eplepsyres.2019.106208] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 08/10/2019] [Accepted: 09/14/2019] [Indexed: 10/26/2022]
Abstract
AIM Vitamin D (Vit D) has been considered as a neurosteroid and has a pivotal role in neuroprotection including epilepsy. Vit D regulator acts via a Vit D receptor (VDR). WAG/Rij rats have a genetically epileptic model of absence epilepsy with comorbidity of depression. The aim of the present study was to investigate the effect of Vit D and paricalcitol (PRC) on WAG/Rij rats. MATERIAL AND METHODS Sixty-three male WAG/Rij rats and seven male Wistar rats were used. The effects of acute and chronic treatment with Vit D (5.000 and 60.000 IU/kg, i.p) and PRC (0.5, 5 and 10 μg/kg, i.p) on absence seizures, and related psychiatric comorbidity were investigated in WAG/Rij rats. Depression-like behavior was assayed by using the forced swimming test (FST) and; anxiety-like behavior by using the open field test (OFT). RESULTS Acute Vit D treatments (5.000 and 60.000 IU/kg) similarly reduced the number and duration of spike-wave discharges (SWDs) and showed anxiolytic-antidepressive effect whereas there were no significant changes in other measured parameters between the daily and the bolus dose of Vit D. Acute administration of PRC (0.5, 5 and 10 μg/kg) showed anti-convulsive and anxiolytic-antidepressive effect. The dose (0.5 μg/kg) of PRC was the most effective dose. Chronic treatment was more effective than acute therapy in all parameters. CONCLUSION The results of the present study demonstrate that Vit D and PRC have antiepileptic and anxiolytic-antidepressive effects on the absence epilepsy in WAG/Rij rats.
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Affiliation(s)
- Hatice Aygun
- Department of Physiology, Faculty of Medicine, University of Tokat Gaziosmanpasa, Tokat, Turkey.
| | - Mustafa Ayyildiz
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey
| | - Erdal Agar
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey
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Çarçak N, Ali I, Powell K, Zheng T, Onat F, O'Brien TJ. Ca
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3.2 T‐type calcium channel mutation influences kindling‐induced thalamic neuronal firing patterns in Genetic Absence Epilepsy Rats From Strasbourg. Epilepsia 2019; 60:1378-1386. [DOI: 10.1111/epi.16076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 05/21/2019] [Accepted: 05/22/2019] [Indexed: 01/30/2023]
Affiliation(s)
- Nihan Çarçak
- Department of Pharmacology Faculty of Pharmacy Istanbul University Istanbul Turkey
- Departments of Medicine and Neurology Royal Melbourne Hospital University of Melbourne Melbourne Victoria Australia
| | - Idrish Ali
- Departments of Medicine and Neurology Royal Melbourne Hospital University of Melbourne Melbourne Victoria Australia
- Departments of Neuroscience and Neurology Central Clinical School Alfred Health Monash University Clayton Victoria Australia
| | - Kim Powell
- Departments of Medicine and Neurology Royal Melbourne Hospital University of Melbourne Melbourne Victoria Australia
- Departments of Neuroscience and Neurology Central Clinical School Alfred Health Monash University Clayton Victoria Australia
| | - Thomas Zheng
- Departments of Medicine and Neurology Royal Melbourne Hospital University of Melbourne Melbourne Victoria Australia
| | - Filiz Onat
- Department of Pharmacology and Clinical Pharmacology Faculty of Medicine Marmara University Istanbul Turkey
- Marmara University Epilepsy Research Center Istanbul Turkey
| | - Terence J. O'Brien
- Departments of Medicine and Neurology Royal Melbourne Hospital University of Melbourne Melbourne Victoria Australia
- Departments of Neuroscience and Neurology Central Clinical School Alfred Health Monash University Clayton Victoria Australia
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Russo E, Citraro R. Pharmacology of epileptogenesis and related comorbidities in the WAG/Rij rat model of genetic absence epilepsy. J Neurosci Methods 2018; 310:54-62. [PMID: 29857008 DOI: 10.1016/j.jneumeth.2018.05.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 05/25/2018] [Accepted: 05/28/2018] [Indexed: 01/23/2023]
Abstract
Animal studies currently represent the best source of information also in the field of epileptogenesis research. Many animal models have been proposed and studied so far both from the pathophysiological and pharmacological point of view. Furthermore, they are widely used for the identification of potentially clinically valuable biomarkers. The WAG/Rij rat model, similarly to other genetic animal strains, represents a suitable animal model of absence epileptogenesis accompanied by depressive-like and cognitive comorbidities. Generally, animal models of epileptogenesis are characterized by an identifiable initial insult (e.g. traumatic brain injury), a latent phase lasting up to the appearance of the first spontaneous seizure and a chronic phase characterized by recurrent spontaneous seizures. In most of genetic models: the initial insult should be defined as the mutation causing epilepsy, which is not clearly defined in the WAG/Rij rat model; the latent phase ends at the appearance of the first spontaneous seizure, which is about 2-3 months of age in WAG/Rij rats and thereafter the chronic phase. WAG/Rij rats also display depressive-like comorbidity around the age of 4 months, which is apparently linked to the development of absence seizures considering both its ontogeny and the fact that drugs affecting absence seizures development also block the development of depressive-like behavior. Finally, WAG/Rij rats also display cognitive impairment in some memory tasks, however, this has not been yet definitively linked to absence seizures development and may represent an epiphenomenon. This review is focused on the effects of pharmacological treatments against epileptogenesis and their effects on comorbidities.
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Affiliation(s)
- Emilio Russo
- Science of Health Department, School of Medicine, University of Catanzaro, Italy.
| | - Rita Citraro
- Science of Health Department, School of Medicine, University of Catanzaro, Italy
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Russo E, Citraro R, Constanti A, Leo A, Lüttjohann A, van Luijtelaar G, De Sarro G. Upholding WAG/Rij rats as a model of absence epileptogenesis: Hidden mechanisms and a new theory on seizure development. Neurosci Biobehav Rev 2016; 71:388-408. [DOI: 10.1016/j.neubiorev.2016.09.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 09/19/2016] [Indexed: 02/06/2023]
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Wormuth C, Lundt A, Henseler C, Müller R, Broich K, Papazoglou A, Weiergräber M. Review: Ca v2.3 R-type Voltage-Gated Ca 2+ Channels - Functional Implications in Convulsive and Non-convulsive Seizure Activity. Open Neurol J 2016; 10:99-126. [PMID: 27843503 PMCID: PMC5080872 DOI: 10.2174/1874205x01610010099] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 05/16/2016] [Accepted: 06/24/2016] [Indexed: 11/22/2022] Open
Abstract
Background: Researchers have gained substantial insight into mechanisms of synaptic transmission, hyperexcitability, excitotoxicity and neurodegeneration within the last decades. Voltage-gated Ca2+ channels are of central relevance in these processes. In particular, they are key elements in the etiopathogenesis of numerous seizure types and epilepsies. Earlier studies predominantly targeted on Cav2.1 P/Q-type and Cav3.2 T-type Ca2+ channels relevant for absence epileptogenesis. Recent findings bring other channels entities more into focus such as the Cav2.3 R-type Ca2+ channel which exhibits an intriguing role in ictogenesis and seizure propagation. Cav2.3 R-type voltage gated Ca2+ channels (VGCC) emerged to be important factors in the pathogenesis of absence epilepsy, human juvenile myoclonic epilepsy (JME), and cellular epileptiform activity, e.g. in CA1 neurons. They also serve as potential target for various antiepileptic drugs, such as lamotrigine and topiramate. Objective: This review provides a summary of structure, function and pharmacology of VGCCs and their fundamental role in cellular Ca2+ homeostasis. We elaborate the unique modulatory properties of Cav2.3 R-type Ca2+ channels and point to recent findings in the proictogenic and proneuroapoptotic role of Cav2.3 R-type VGCCs in generalized convulsive tonic–clonic and complex-partial hippocampal seizures and its role in non-convulsive absence like seizure activity. Conclusion: Development of novel Cav2.3 specific modulators can be effective in the pharmacological treatment of epilepsies and other neurological disorders.
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Affiliation(s)
- Carola Wormuth
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Andreas Lundt
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Christina Henseler
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Ralf Müller
- Department of Psychiatry and Psychotherapy, University of Cologne, Faculty of Medicine, Cologne, Germany
| | - Karl Broich
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Anna Papazoglou
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Marco Weiergräber
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
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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.
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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
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Regionally specific expression of high-voltage-activated calcium channels in thalamic nuclei of epileptic and non-epileptic rats. Mol Cell Neurosci 2014; 61:110-22. [PMID: 24914823 DOI: 10.1016/j.mcn.2014.06.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 05/30/2014] [Accepted: 06/05/2014] [Indexed: 11/21/2022] Open
Abstract
The polygenic origin of generalized absence epilepsy results in dysfunction of ion channels that allows the switch from physiological asynchronous to pathophysiological highly synchronous network activity. Evidence from rat and mouse models of absence epilepsy indicates that altered Ca(2+) channel activity contributes to cellular and network alterations that lead to seizure activity. Under physiological circumstances, high voltage-activated (HVA) Ca(2+) channels are important in determining the thalamic firing profile. Here, we investigated a possible contribution of HVA channels to the epileptic phenotype using a rodent genetic model of absence epilepsy. In this study, HVA Ca(2+) currents were recorded from neurons of three different thalamic nuclei that are involved in both sensory signal transmission and rhythmic-synchronized activity during epileptic spike-and-wave discharges (SWD), namely the dorsal part of the lateral geniculate nucleus (dLGN), the ventrobasal thalamic complex (VB) and the reticular thalamic nucleus (NRT) of epileptic Wistar Albino Glaxo rats from Rijswijk (WAG/Rij) and non-epileptic August Copenhagen Irish (ACI) rats. HVA Ca(2+) current densities in dLGN neurons were significantly increased in epileptic rats compared with non-epileptic controls while other thalamic regions revealed no differences between the strains. Application of specific channel blockers revealed that the increased current was carried by L-type Ca(2+) channels. Electrophysiological evidence of increased L-type current correlated with up-regulated mRNA and protein expression of a particular L-type channel, namely Cav1.3, in dLGN of epileptic rats. No significant changes were found for other HVA Ca(2+) channels. Moreover, pharmacological inactivation of L-type Ca(2+) channels results in altered firing profiles of thalamocortical relay (TC) neurons from non-epileptic rather than from epileptic rats. While HVA Ca(2+) channels influence tonic and burst firing in ACI and WAG/Rij differently, it is discussed that increased Cav1.3 expression may indirectly contribute to increased robustness of burst firing and thereby the epileptic phenotype of absence epilepsy.
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Brain protein expression changes in WAG/Rij rats, a genetic rat model of absence epilepsy after peripheral lipopolysaccharide treatment. Brain Behav Immun 2014; 35:86-95. [PMID: 24021561 DOI: 10.1016/j.bbi.2013.09.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 09/02/2013] [Accepted: 09/02/2013] [Indexed: 12/16/2022] Open
Abstract
Peripheral injection of bacterial lipopolysaccharide (LPS) facilitates 8-10Hz spike-wave discharges (SWD) characterizing absence epilepsy in WAG/Rij rats. It is unknown however, whether peripherally administered LPS is able to alter the generator areas of epileptic activity at the molecular level. We injected 1mg/kg dose of LPS intraperitoneally into WAG/Rij rats, recorded the body temperature and EEG, and examined the protein expression changes of the proteome 12h after injection in the fronto-parietal cortex and thalamus. We used fluorescent two-dimensional differential gel electrophoresis to investigate the expression profile. We found 16 differentially expressed proteins in the fronto-parietal cortex and 35 proteins in the thalamus. It is known that SWD genesis correlates with the transitional state of sleep-wake cycle thus we performed meta-analysis of the altered proteins in relation to inflammation, epilepsy as well as sleep. The analysis revealed that all categories are highly represented by the altered proteins and these protein-sets have considerable overlap. Protein network modeling suggested that the alterations in the proteome were largely induced by the immune response, which invokes the NFkB signaling pathway. The proteomics and computational analysis verified the known functional interplay between inflammation, epilepsy and sleep and highlighted proteins that are involved in their common synaptic mechanisms. Our physiological findings support the phenomenon that high dose of peripheral LPS injection increases SWD-number, modifies its duration as well as the sleep-wake stages and decreases body temperature.
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Epps SA, Weinshenker D. Rhythm and blues: animal models of epilepsy and depression comorbidity. Biochem Pharmacol 2012; 85:135-46. [PMID: 22940575 DOI: 10.1016/j.bcp.2012.08.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Revised: 08/16/2012] [Accepted: 08/17/2012] [Indexed: 12/12/2022]
Abstract
Clinical evidence shows a strong, bidirectional comorbidity between depression and epilepsy that is associated with decreased quality of life and responsivity to pharmacotherapies. At present, the neurobiological underpinnings of this comorbidity remain hazy. To complicate matters, anticonvulsant drugs can cause mood disturbances, while antidepressant drugs can lower seizure threshold, making it difficult to treat patients suffering from both depression and epilepsy. Animal models have been created to untangle the mechanisms behind the relationship between these disorders and to serve as screening tools for new therapies targeted to treat both simultaneously. These animal models are based on chemical interventions (e.g. pentylenetetrazol, kainic acid, pilocarpine), electrical stimulations (e.g. kindling, electroshock), and genetic/selective breeding paradigms (e.g. genetically epilepsy-prone rats (GEPRs), genetic absence epilepsy rat from Strasbourg (GAERS), WAG/Rij rats, swim lo-active rats (SwLo)). Studies on these animal models point to some potential mechanisms that could explain epilepsy and depression comorbidity, such as various components of the dopaminergic, noradrenergic, serotonergic, and GABAergic systems, as well as key brain regions, like the amygdala and hippocampus. These models have also been used to screen possible therapies. The purpose of the present review is to highlight the importance of animal models in research on comorbid epilepsy and depression and to explore the contributions of these models to our understanding of the mechanisms and potential treatments for these disorders.
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Affiliation(s)
- S Alisha Epps
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA.
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Voltage-Gated Ca2+ Channel Mediated Ca2+ Influx in Epileptogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:1219-47. [DOI: 10.1007/978-94-007-2888-2_55] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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The prevention of behavioral consequences of idiopathic generalized epilepsy: Evidence from rodent models. Neurosci Lett 2011; 497:177-84. [DOI: 10.1016/j.neulet.2011.02.034] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Accepted: 02/15/2011] [Indexed: 12/29/2022]
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Voltage-gated calcium channels in the etiopathogenesis and treatment of absence epilepsy. ACTA ACUST UNITED AC 2010; 62:245-71. [DOI: 10.1016/j.brainresrev.2009.12.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Revised: 12/10/2009] [Accepted: 12/11/2009] [Indexed: 12/21/2022]
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Watanabe Y, Takechi K, Fujiwara A, Kamei C. Effects of antiepileptics on behavioral and electroencephalographic seizure induced by pentetrazol in mice. J Pharmacol Sci 2010; 112:282-9. [PMID: 20168048 DOI: 10.1254/jphs.09225fp] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
The present study was undertaken to investigate changes of the electroencephalogram (EEG) induced by pentetrazol (PTZ) in comparison with behavioral seizures in mice. Under pentobarbital anesthesia, mice were fixed to a stereotaxic apparatus, and electrodes were implanted into the frontal and occipital cortex. Behavioral and EEG changes were observed for 30 min following PTZ administration. After PTZ administration, mice showed myoclonic seizure (MCL) and clonic seizure (CL) in order. At the same time, spiking activity and spike-wave discharge in the cortex were observed. Phenobarbital, sodium valproate, diazepam, ethosuximide, and gabapentin caused a dose-dependent shortening of the duration of MCL and CL. In addition, they shortened the duration of spiking activity and spike-wave discharge dose-dependently. Moreover, phenytoin significantly inhibited the duration of spiking activity. It can be concluded that PTZ-induced spiking activity and spike-wave discharge serve as useful indices to assess the potential of antiepileptic activity in absence and MCLs in humans. Moreover, it is supposed that employing an index of EEG activity in addition to that of behavioral activity is desirable for objectivity.
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Affiliation(s)
- Yusuke Watanabe
- Department of Medicinal Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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Russo E, Citraro R, Scicchitano F, De Fazio S, Di Paola ED, Constanti A, De Sarro G. Comparison of the antiepileptogenic effects of an early long-term treatment with ethosuximide or levetiracetam in a genetic animal model of absence epilepsy. Epilepsia 2009; 51:1560-9. [PMID: 19919665 DOI: 10.1111/j.1528-1167.2009.02400.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE Epilepsy is a heterogeneous syndrome characterized by recurrent, spontaneous seizures; continuous medication is, therefore, necessary, even after the seizures have long been suppressed with antiepileptic drug (AED) treatments. The most disturbing issue is the inability of AEDs to provide a persistent cure, because these compounds generally suppress the occurrence of epileptic seizures without necessarily having antiepileptogenic properties. The aim of our experiments was to determine, in the WAG/Rij model of absence epilepsy, if early long-term treatment with some established antiabsence drugs might prevent the development of seizures, and whether such an effect could be sustained. METHODS WAG/Rij rats were treated for ∼3.5 months (starting at 1.5 months of age, before seizure onset) with either ethosuximide (ETH; drug of choice for absence epilepsy) or levetiracetam (LEV; a broad-spectrum AED with antiabsence and antiepileptogenic properties). RESULTS We have demonstrated that both drugs are able to reduce the development of absence seizures, exhibiting antiepileptogenic effects in this specific animal model. DISCUSSION These findings suggest that absence epilepsy in this strain of rats very likely follows an epileptogenic process during life and that early therapeutic intervention is possible, thereby opening a new area of research for absence epilepsy and AED treatment strategies.
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Affiliation(s)
- Emilio Russo
- Department of Experimental and Clinical Medicine, School of Medicine, University of Catanzaro, Catanzaro, Italy
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Weiergräber M, Henry M, Ho MS, Struck H, Hescheler J, Schneider T. Altered thalamocortical rhythmicity in Cav2.3-deficient mice. Mol Cell Neurosci 2008; 39:605-18. [DOI: 10.1016/j.mcn.2008.08.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 07/28/2008] [Accepted: 08/13/2008] [Indexed: 01/18/2023] Open
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Liu XB, Coble J, van Luijtelaar G, Jones EG. Reticular nucleus-specific changes in alpha3 subunit protein at GABA synapses in genetically epilepsy-prone rats. Proc Natl Acad Sci U S A 2007; 104:12512-7. [PMID: 17630284 PMCID: PMC1916487 DOI: 10.1073/pnas.0705320104] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Differential composition of GABA(A) receptor (GABA(A)R) subunits underlies the variability of fast inhibitory synaptic transmission; alteration of specific GABA(A)R subunits in localized brain regions may contribute to abnormal brain states such as absence epilepsy. We combined immunocytochemistry and high-resolution ImmunoGold electron microscopy to study cellular and subcellular localization of GABA(A)R alpha1, alpha3, and beta2/beta3 subunits in ventral posterior nucleus (VP) and reticular nucleus (RTN) of control rats and WAG/Rij rats, a genetic model of absence epilepsy. In control rats, alpha1 subunits were prominent at inhibitory synapses in VP and much less prominent in RTN; in contrast, the alpha3 subunit was highly evident at inhibitory synapses in RTN. beta2/beta3 subunits were evenly distributed at inhibitory synapses in both VP and RTN. ImmunoGold particles representing all subunits were concentrated at postsynaptic densities with no extrasynaptic localization. Calculated mean number of particles for alpha1 subunit per postsynaptic density in nonepileptic VP was 6.1 +/- 3.7, for alpha3 subunit in RTN it was 6.6 +/- 3.4, and for beta2/beta3 subunits in VP and RTN the mean numbers were 3.7 +/- 1.3 and 3.5 +/- 1.2, respectively. In WAG/Rij rats, there was a specific loss of alpha3 subunit immunoreactivity at inhibitory synapses in RTN, without reduction in alpha3 subunit mRNA or significant change in immunostaining for other markers of RTN cell identity such as GABA or parvalbumin. alpha3 immunostaining in cortex was unchanged. Subtle, localized changes in GABA(A)R expression acting at highly specific points in the interconnected thalamocortical network lie at the heart of idiopathic generalized epilepsy.
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Affiliation(s)
- Xiao-Bo Liu
- *Center for Neuroscience
- Department of Human Anatomy and Cell Biology, University of California, Davis, CA 95616; and
| | | | - Gilles van Luijtelaar
- Nijmegen Institute for Cognition and Information–Biological Psychology, Radboud University Nijmegen, 6500 HC Nijmegen, The Netherlands
| | - Edward G. Jones
- *Center for Neuroscience
- To whom correspondence should be addressed at:
Center for Neuroscience, 1544 Newton Court, Davis, CA 95618. E-mail:
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Nagaeva DV, Akhmadeev AV. Structural organization, neurochemical characteristics, and connections of the reticular nucleus of the thalamus. ACTA ACUST UNITED AC 2006; 36:987-95. [PMID: 17024337 DOI: 10.1007/s11055-006-0134-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2004] [Accepted: 09/14/2005] [Indexed: 12/23/2022]
Abstract
This review analyzes current concepts of the structural organization and ultrastructure of the reticular nucleus of the thalamus (RNT) and the neurochemical characteristics of its neurons. The topography, cytoarchitectonics, and neuronal organization of this nucleus are considered in detail, as are questions of its neurogenesis. Neurochemical data clarifying the representation of neurotransmitter systems in the RNT and data on neuropeptides synthesized in its neurons are systematized. The complex ultrastructural organization of the RNT is characterized in terms of recent data from state-of-the-art immunocytochemical methods allowing localization of glutamatergic and GABAergic receptors on synaptic elements. Data on the afferent and efferent connections of the RNT demonstrate its influences on various parts of the brain and the specific features of its interactions with cortical formations.
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Affiliation(s)
- D V Nagaeva
- Department of Human and Animal Morphology and Physiology, Bashkir State University, Ufa
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Weiergräber M, Henry M, Krieger A, Kamp M, Radhakrishnan K, Hescheler J, Schneider T. Altered seizure susceptibility in mice lacking the Ca(v)2.3 E-type Ca2+ channel. Epilepsia 2006; 47:839-50. [PMID: 16686648 DOI: 10.1111/j.1528-1167.2006.00541.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE Recently the Ca(v)2.3 (E/R-type) voltage-gated calcium channel (VGCC) has turned out to be not only a potential target for different antiepileptic drugs (e.g., lamotrigine, topiramate) but also a crucial component in the pathogenesis of absence epilepsy, human juvenile myoclonic epilepsy (JME), and epileptiform activity in CA1 neurons. The aim of our study was to perform an electroencephalographic analysis, seizure-susceptibility testing, and histomorphologic characterization of Ca(v)2.3-/- mice to unravel the functional relevance of Ca(v)2.3 in ictogenesis. METHODS Generalized and brain-specific Ca(v)2.3 knockout animals were analyzed for spontaneous epileptiform discharges by using both electrocorticographic and deep intracerebral recordings. In addition, convulsive seizure activity was induced by systemic administration of either 4-aminopyridine (4-AP; 10 mg/kg, i.p.) or pentylenetetrazol (PTZ; 80 mg/kg, s.c.) to reveal possible alterations in seizure susceptibility. Besides histomorphologic analysis, expression studies of other voltage-gated Ca2+ channels in Ca(v)2.3-/- brains were carried out by using semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). RESULTS Both electrocorticographic and deep intrahippocampal recordings exhibited no spontaneous epileptiform discharges indicative of convulsive or nonconvulsive seizure activity during long-term observation. Gross histology and expression levels of other voltage-gated Ca2+ channels remained unchanged in various brain regions. Surprisingly, PTZ-induced seizure susceptibility was dramatically reduced in Ca(v)2.3-deficient mice, whereas 4-AP sensitivity remained unchanged. CONCLUSIONS Ca(v)2.3 ablation results in seizure resistance, strongly supporting recent findings in CA1 neurons that Ca(v)2.3 triggers epileptiform activity in specialized neurons via plateau potentials and afterdepolarizations. We provide novel insight into the functional involvement of Ca(v)2.3 in ictogenesis and seizure susceptibility on the whole-animal level.
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van de Bovenkamp-Janssen MC, Akhmadeev A, Kalimullina L, Nagaeva DV, van Luijtelaar ELJM, Roubos EW. Synaptology of the rostral reticular thalamic nucleus of absence epileptic WAG/Rij rats. Neurosci Res 2004; 48:21-31. [PMID: 14687878 DOI: 10.1016/j.neures.2003.09.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The adult WAG/Rij rat is a well-established animal model for human absence epilepsy characterized by the presence of spike-wave discharges (SWDs). The pacemaking activity of the rostral reticular thalamic nucleus (rRTN) has been demonstrated to be essential for SWD maintenance. We investigated if SWD maintenance can be related to the synaptic organization of the rRTN, by studying the ultrastructure of the rRTN of absence epileptic WAG/Rij rats in comparison with that of non-epileptic, age-matched ACI control rats. In WAG/Rij rats, D-, L- and F-type terminals constitute the synaptic organization of the rRTN. D-type synapses, especially axo-dendritic ones, occur frequently. L- and F-type terminals are common but less frequent than D-type terminals. Semi-quantitative observations indicate that all terminal types are present on different parts of the postsynaptic neuron, but in different numbers: they are frequent on dendrites, common on somata and axons, and occur occasionally on dendritic spines. In addition, occasionally an F-type terminal was observed on the axon hillock. The three terminal types are also involved in multiple synaptic configurations, convergent as well as divergent, with dendrites, somata, axon hillocks and axons as postsynaptic structures. Convergent synaptic configurations outnumber divergent ones. The synaptic organization of the rRTN of the non-epileptic ACI rat appears to be very similar to that of the epileptic WAG/Rij rat. This indicates that SWD maintenance in the WAG/Rij rat does not depend on a different synaptic organization of the rRTN.
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Affiliation(s)
- M C van de Bovenkamp-Janssen
- Department of Cellular Animal Physiology, Nijmegen Institute for Neurosciences, University of Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
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