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Li HH, Lin PJ, Wang WH, Tseng LH, Tung H, Liu WY, Lin CL, Liu CH, Liao WC, Hung CS, Ho YJ. Treatment effects of the combination of ceftriaxone and valproic acid on neuronal and behavioural functions in a rat model of epilepsy. Exp Physiol 2021; 106:1814-1828. [PMID: 34086374 DOI: 10.1113/ep089624] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/03/2021] [Indexed: 01/29/2023]
Abstract
NEW FINDINGS What is the central question of this study? Imbalance of activities between GABAergic and glutamatergic systems is involved in epilepsy. It is not known whether simultaneously increasing GABAergic and decreasing glutamatergic activity using valproic acid and ceftriaxone, respectively, leads to better seizure control. What is the central question of this study? Ceftriaxone suppressed seizure and cognitive deficits and restored neuronal density and the number of newborn cells in the hippocampus in a rat model of epilepsy. Combined treatment with ceftriaxone and valproic acid showed additive effects in seizure suppression. ABSTRACT The pathophysiology of epilepsy is typically considered as an imbalance between inhibitory GABA and excitatory glutamate neurotransmission. Valproic acid (Val), a GABA agonist, is one of the first-line antiepileptic drugs in the treatment of epilepsy, but it exhibits adverse effects. Ceftriaxone (CEF) elevates expression of glutamate transporter-1, enhances the reuptake of synaptic glutamate, increases the number of newborn cells and exhibits neuroprotective effects in animal studies. In this study, we evaluated effects of the combination of CEF and Val on behavioural and neuronal measures in a rat epilepsy model. Male Wistar rats were injected i.p. with pentylenetetrazol (35 mg/kg, every other day for 13 days) to induce the epilepsy model. Ceftriaxone (10 or 50 mg/kg), Val (50 or 100 mg/kg) or the combination of CEF and Val were injected daily after the fourth pentylenetetrazol injection for seven consecutive days. Epileptic rats exhibited seizure and impairments in motor and cognitive functions. Treatment with CEF and Val reduced the seizure and enhanced motor and cognitive functions in a dose-dependent manner. The combination of CEF (10 mg/kg) and Val (50 mg/kg) improved behaviours considerably. Histologically, compared with control animals, epileptic rats exhibited lower neuronal density and a reduction in hippocampal newborn cells but higher apoptosis in the basolateral amygdala, all of which were restored by the treatment with CEF, Val or the combination of CEF and Val. The study findings demonstrated that the combination of low doses of CEF and Val has beneficial effects on seizure suppression, neuroprotection and improvement in motor and cognitive functions in epilepsy.
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Affiliation(s)
- Hsin-Hua Li
- Department of Medical Research, Institute of Medicine, Chung Shan Medical University Hospital, Chung Shan Medical University, Taichung, Taiwan, Republic of China
| | - Pin-Jiun Lin
- Department of Psychology, Chung Shan Medical University Hospital, Chung Shan Medical University, Taichung, Taiwan, Republic of China
| | - Wei-Han Wang
- Department of Psychology, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China
| | - Li-Ho Tseng
- Graduate School of Environmental Management, Tajen University, Pingtung, Taiwan, Republic of China
| | - Hsin Tung
- Division of Epilepsy, Center of Faculty Development, Neurological Institute, Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China
| | - Wen-Yuan Liu
- Department of Psychology, Chung Shan Medical University Hospital, Chung Shan Medical University, Taichung, Taiwan, Republic of China
| | - Chih-Li Lin
- Department of Medical Research, Institute of Medicine, Chung Shan Medical University Hospital, Chung Shan Medical University, Taichung, Taiwan, Republic of China
| | - Chiung-Hui Liu
- Department of Anatomy, Faculty of Medicine, Chung Shan Medical University, Taichung, Taiwan, Republic of China
| | - Wen-Chieh Liao
- Department of Anatomy, Faculty of Medicine, Chung Shan Medical University, Taichung, Taiwan, Republic of China
| | - Ching-Sui Hung
- Occupational Safety and Health Office, Taipei City Hospital, Taipei, Taiwan, Republic of China
| | - Ying-Jui Ho
- Department of Psychology, Chung Shan Medical University Hospital, Chung Shan Medical University, Taichung, Taiwan, Republic of China
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Chauvette S, Soltani S, Seigneur J, Timofeev I. In vivo models of cortical acquired epilepsy. J Neurosci Methods 2016; 260:185-201. [PMID: 26343530 PMCID: PMC4744568 DOI: 10.1016/j.jneumeth.2015.08.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 08/24/2015] [Accepted: 08/26/2015] [Indexed: 10/23/2022]
Abstract
The neocortex is the site of origin of several forms of acquired epilepsy. Here we provide a brief review of experimental models that were recently developed to study neocortical epileptogenesis as well as some major results obtained with these methods. Most of neocortical seizures appear to be nocturnal and it is known that neuronal activities reveal high levels of synchrony during slow-wave sleep. Therefore, we start the review with a description of mechanisms of neuronal synchronization and major forms of synchronized normal and pathological activities. Then, we describe three experimental models of seizures and epileptogenesis: ketamine-xylazine anesthesia as feline seizure triggered factor, cortical undercut as cortical penetrating wound model and neocortical kindling. Besides specific technical details describing these models we also provide major features of pathological brain activities recorded during epileptogenesis and seizures. The most common feature of all models of neocortical epileptogenesis is the increased duration of network silent states that up-regulates neuronal excitability and eventually leads to epilepsy.
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Affiliation(s)
- Sylvain Chauvette
- Centre de recherche de l'Institut universitaire en santé mentale de Québec (CRIUSMQ), Local F-6500, 2601 de la Canardière, Québec, QC, Canada G1J2G3
| | - Sara Soltani
- Centre de recherche de l'Institut universitaire en santé mentale de Québec (CRIUSMQ), Local F-6500, 2601 de la Canardière, Québec, QC, Canada G1J2G3; Department of Psychiatry and Neuroscience, Université Laval, Québec, Canada
| | - Josée Seigneur
- Centre de recherche de l'Institut universitaire en santé mentale de Québec (CRIUSMQ), Local F-6500, 2601 de la Canardière, Québec, QC, Canada G1J2G3
| | - Igor Timofeev
- Centre de recherche de l'Institut universitaire en santé mentale de Québec (CRIUSMQ), Local F-6500, 2601 de la Canardière, Québec, QC, Canada G1J2G3; Department of Psychiatry and Neuroscience, Université Laval, Québec, Canada.
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Abstract
All brain normal or pathological activities occur in one of the states of vigilance: wake, slow-wave sleep, or REM sleep. Neocortical seizures preferentially occur during slow-wave sleep. We provide a description of neuronal behavior and mechanisms mediating such a behavior within neocortex taking place in natural states of vigilance as well as during seizures pointing to similarities and differences exhibited during sleep and seizures. A concept of epileptic focus is described using a model of cortical undercut, because in that model, the borders of the focus are well defined. In this model, as in other models of acquired epilepsy, the main factor altering excitability is deafferentation, which upregulates neuronal excitability that promotes generation of seizures. Periods of disfacilitation recorded during slow-wave sleep further upregulate neuronal excitability. It appears that the state of neurons and neuronal network in the epileptic focus produced by deafferentation are such that seizures cannot be generated there. Instead, seizures always start around the perimeter of the undercut cortex. Therefore, we define these areas as the seizure focus. In this zone, neuronal connectivity and excitability are moderately enhanced, lowering the threshold for seizure generation.
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Timofeev I, Sejnowski TJ, Bazhenov M, Chauvette S, Grand LB. Age dependency of trauma-induced neocortical epileptogenesis. Front Cell Neurosci 2013; 7:154. [PMID: 24065884 PMCID: PMC3776140 DOI: 10.3389/fncel.2013.00154] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 08/26/2013] [Indexed: 11/13/2022] Open
Abstract
Trauma and brain infection are the primary sources of acquired epilepsy, which can occur at any age and may account for a high incidence of epilepsy in developing countries. We have explored the hypothesis that penetrating cortical wounds cause deafferentation of the neocortex, which triggers homeostatic plasticity and lead to epileptogenesis (Houweling etal., 2005). In partial deafferentation experiments of adult cats, acute seizures occurred in most preparations and chronic seizures occurred weeks to months after the operation in 65% of the animals (Nita etal., 2006,2007; Nita and Timofeev, 2007). Similar deafferentation of young cats (age 8-12 months) led to some acute seizures, but we never observed chronic seizure activity even though there was enhanced slow-wave activity in the partially deafferented hemisphere during quiet wakefulness. This suggests that despite a major trauma, the homeostatic plasticity in young animals was able to restore normal levels of cortical excitability, but in fully adult cats the mechanisms underlying homeostatic plasticity may lead to an unstable cortical state. To test this hypothesis we made an undercut in the cortex of an elderly cat. After several weeks this animal developed seizure activity. These observations may lead to an intervention after brain trauma that prevents epileptogenesis from occurring in adults.
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Affiliation(s)
- Igor Timofeev
- Department of Psychiatry and Neuroscience, Université LavalQuébec, QC, Canada
- Le Centre de Recherche de l’Institut Universitaire en santé Mentale de QuébecQuébec, QC, Canada
| | - Terrence J. Sejnowski
- Computational Neurobiology Laboratory, Howard Hughes Medical Institute, The Salk Institute for Biological StudiesLa Jolla, CA, USA
- Division of Biological Sciences, University of California at San DiegoLa Jolla, CA, USA
| | - Maxim Bazhenov
- Department of Cell Biology and Neuroscience, University of California at RiversideRiverside, CA, USA
| | - Sylvain Chauvette
- Le Centre de Recherche de l’Institut Universitaire en santé Mentale de QuébecQuébec, QC, Canada
| | - Laszlo B. Grand
- Le Centre de Recherche de l’Institut Universitaire en santé Mentale de QuébecQuébec, QC, Canada
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Nita DA, Cissé Y, Timofeev I. State-dependent slow outlasting activities following neocortical kindling in cats. Exp Neurol 2008; 211:456-68. [PMID: 18420200 DOI: 10.1016/j.expneurol.2008.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2007] [Revised: 02/01/2008] [Accepted: 02/16/2008] [Indexed: 11/19/2022]
Abstract
Some forms of electrographic seizures are generated at the level of the cortical network. Neocortical kindling exhibits a resistance to produce generalized convulsive seizures, and therefore, it was rather difficult to use it to study the cortical epileptogenesis. Here, using supra-threshold cortical kindling, we report electrophysiological patterns of field-potential synchronization and intracellular activities in chronically implanted non-anesthetized cats, during different states of vigilance, and during acute seizures elicited by prolonged (20-60 s) electrical stimulation. Acute seizures were easily elicited during transition from slow-wave sleep (SWS) to waking state. The seizures were mainly clonic accompanied with tonic components followed by prolonged postictal depression. Delayed rhythmic outlasting activities (OA) at approximately 1.5 Hz, first time reported here, followed the postictal depression, and lasted up to 2 h. These activities were clear during waking state, slightly reduced during SWS and completely absent during rapid-eye movement sleep. They started focally and following daily stimulations generalized over the entire cortical surface. Extra- and intracellular neuronal recordings during OA displayed spike-doublets, built on the summation of successive excitatory postsynaptic potentials and fast-prepotentials, entailing an increased dendritic excitation. Our results suggest that such rhythmic long-lasting oscillatory activity outlasting seizures are the key factor of epileptogenesis, leading to epilepsy.
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Affiliation(s)
- Dragos A Nita
- Department of Anatomy and Physiology, Laval University, Centre de Recherche Université Laval Robert-Giffard, 2601 de la Canardière, Québec, Canada G1J 2G3
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