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Wu PP, Cao BR, Tian FY, Gao ZB. Development of SV2A Ligands for Epilepsy Treatment: A Review of Levetiracetam, Brivaracetam, and Padsevonil. Neurosci Bull 2024; 40:594-608. [PMID: 37897555 PMCID: PMC11127901 DOI: 10.1007/s12264-023-01138-2] [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: 03/27/2023] [Accepted: 08/16/2023] [Indexed: 10/30/2023] Open
Abstract
Epilepsy is a common neurological disorder that is primarily treated with antiseizure medications (ASMs). Although dozens of ASMs are available in the clinic, approximately 30% of epileptic patients have medically refractory seizures; other limitations in most traditional ASMs include poor tolerability and drug-drug interactions. Therefore, there is an urgent need to develop alternative ASMs. Levetiracetam (LEV) is a first-line ASM that is well tolerated, has promising efficacy, and has little drug-drug interaction. Although it is widely accepted that LEV acts through a unique therapeutic target synaptic vesicle protein (SV) 2A, the molecular basis of its action remains unknown. Even so, the next-generation SV2A ligands against epilepsy based on the structure of LEV have achieved clinical success. This review highlights the research and development (R&D) process of LEV and its analogs, brivaracetam and padsevonil, to provide ideas and experience for the R&D of novel ASMs.
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Affiliation(s)
- Peng-Peng Wu
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bi-Rong Cao
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fu-Yun Tian
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhongshan, 528400, China.
| | - Zhao-Bing Gao
- Center for Neurological and Psychiatric Research and Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhongshan, 528400, China.
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Kumar H, Katyal J, Kumar Gupta Y. Effect of U50488, a selective kappa opioid receptor agonist and levetiracetam against lithium-pilocarpine-induced status epilepticus, spontaneous convulsive seizures and related cognitive impairment. Neurosci Lett 2023; 815:137477. [PMID: 37714287 DOI: 10.1016/j.neulet.2023.137477] [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: 07/13/2023] [Revised: 08/16/2023] [Accepted: 08/29/2023] [Indexed: 09/17/2023]
Abstract
PURPOSE Kappa opioid receptor (KOR) agonists have anticonvulsant effect but their antiepileptogenic effect is unknown. U50488, a selective KOR agonist is used to determine its effect on status epilepticus (SE), spontaneous convulsive seizures (SS) and cognitive impairment in rat lithium-pilocarpine SE model. Effect of an antiepileptic drug levetiracetam is also studied. METHOD Male Wistar rats with SE were divided into three groups namely, LiP, LiP + U50488 (10 mg/kg, i.p.) and LiP + levetiracetam (400 mg/kg, i.p.) group. SE was terminated after 90 min of its onset with diazepam (15 mg/kg, i.p.) and phenobarbitone (25 mg/kg, i.p.). Drug treatment was started after 15 min of onset of SE and repeated once after 4 h. Rats were video monitored 12 h daily (9 AM to 9 PM) to determine severity of SE using modified Racine scale and onset and frequency of SS from day 0 to day 21. Morris water maze (MWM) test was done at baseline i.e. day -1 (before lithium administration) and day 22, to assess cognitive impairment. RESULTS As compared to LiP, U50488 decreased the severity of SE (1.98 ± 0.13 vs 2.95 ± 0.12; p-value < 0.0001) but not levetiracetam (2.62 ± 0.09; p-value = 0.3112). Survival increased with both U50488 (90%, n = 10) and levetiracetam (81.8%, n = 11) as compared to NS (56.2%, n = 16). No effect on onset and frequency of SS was found in U50488/levetiracetam group. U50488 improved seizures-induced cognitive impairment. Levetiracetam group showed thigmotactic (wall hugging) behaviour in MWM in 8 out of 9 rats. CONCLUSION Acute treatment with U50488, a kappa opioid receptor agonist has a beneficial effect on SE, SE-related mortality and memory impairment. The dual protective effect of U50488 on seizures and related cognitive impairment is advantageous over currently used antiseizure drugs which are known to cause cognitive impairment.
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Affiliation(s)
- Hemant Kumar
- Department of Pharmacology, Faculty of Medicine and Health Sciences, SGT University, Gurgaon, Haryana, India.
| | - Jatinder Katyal
- Department of Pharmacology, All India Institute of Medical Sciences (AIIMS), New Delhi, India
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Rodent Models of Audiogenic Epilepsy: Genetic Aspects, Advantages, Current Problems and Perspectives. Biomedicines 2022; 10:biomedicines10112934. [PMID: 36428502 PMCID: PMC9687921 DOI: 10.3390/biomedicines10112934] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/10/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022] Open
Abstract
Animal models of epilepsy are of great importance in epileptology. They are used to study the mechanisms of epileptogenesis, and search for new genes and regulatory pathways involved in the development of epilepsy as well as screening new antiepileptic drugs. Today, many methods of modeling epilepsy in animals are used, including electroconvulsive, pharmacological in intact animals, and genetic, with the predisposition for spontaneous or refractory epileptic seizures. Due to the simplicity of manipulation and universality, genetic models of audiogenic epilepsy in rodents stand out among this diversity. We tried to combine data on the genetics of audiogenic epilepsy in rodents, the relevance of various models of audiogenic epilepsy to certain epileptic syndromes in humans, and the advantages of using of rodent strains predisposed to audiogenic epilepsy in current epileptology.
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Contreras-García IJ, Cárdenas-Rodríguez N, Romo-Mancillas A, Bandala C, Zamudio SR, Gómez-Manzo S, Hernández-Ochoa B, Mendoza-Torreblanca JG, Pichardo-Macías LA. Levetiracetam Mechanisms of Action: From Molecules to Systems. Pharmaceuticals (Basel) 2022; 15:ph15040475. [PMID: 35455472 PMCID: PMC9030752 DOI: 10.3390/ph15040475] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 04/06/2022] [Accepted: 04/06/2022] [Indexed: 11/16/2022] Open
Abstract
Epilepsy is a chronic disease that affects millions of people worldwide. Antiepileptic drugs (AEDs) are used to control seizures. Even though parts of their mechanisms of action are known, there are still components that need to be studied. Therefore, the search for novel drugs, new molecular targets, and a better understanding of the mechanisms of action of existing drugs is still crucial. Levetiracetam (LEV) is an AED that has been shown to be effective in seizure control and is well-tolerable, with a novel mechanism of action through an interaction with the synaptic vesicle protein 2A (SV2A). Moreover, LEV has other molecular targets that involve calcium homeostasis, the GABAergic system, and AMPA receptors among others, that might be integrated into a single mechanism of action that could explain the antiepileptogenic, anti-inflammatory, neuroprotective, and antioxidant properties of LEV. This puts it as a possible multitarget drug with clinical applications other than for epilepsy. According to the above, the objective of this work was to carry out a comprehensive and integrative review of LEV in relation to its clinical uses, structural properties, therapeutical targets, and different molecular, genetic, and systemic action mechanisms in order to consider LEV as a candidate for drug repurposing.
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Affiliation(s)
| | - Noemí Cárdenas-Rodríguez
- Laboratorio de Neurociencias, Subdirección de Medicina Experimental, Instituto Nacional de Pediatría, Ciudad de México 04530, Mexico;
| | - Antonio Romo-Mancillas
- Laboratorio de Diseño Asistido por Computadora y Síntesis de Fármacos, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario, Querétaro 76010, Mexico;
| | - Cindy Bandala
- Neurociencia Básica, Instituto Nacional de Rehabilitación LGII, Secretaría de Salud, Ciudad de México 14389, Mexico;
- Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México 11340, Mexico
| | - Sergio R. Zamudio
- Departamento de Fisiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México 07738, Mexico;
| | - Saúl Gómez-Manzo
- Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México 04530, Mexico;
| | - Beatriz Hernández-Ochoa
- Laboratorio de Inmunoquímica, Hospital Infantil de México Federico Gómez, Secretaría de Salud, Ciudad de México 06720, Mexico;
| | - Julieta Griselda Mendoza-Torreblanca
- Laboratorio de Neurociencias, Subdirección de Medicina Experimental, Instituto Nacional de Pediatría, Ciudad de México 04530, Mexico;
- Correspondence: (J.G.M.-T.); (L.A.P.-M.); Tel.: +52-55-1084-0900 (ext. 1441) (J.G.M.-T.)
| | - Luz Adriana Pichardo-Macías
- Departamento de Fisiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México 07738, Mexico;
- Correspondence: (J.G.M.-T.); (L.A.P.-M.); Tel.: +52-55-1084-0900 (ext. 1441) (J.G.M.-T.)
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Li L, Chen GD, Salvi R. Effect of antiepileptic drug levetiracetam on cochlear function. Hear Res 2021; 415:108396. [PMID: 34903423 DOI: 10.1016/j.heares.2021.108396] [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: 06/07/2021] [Revised: 11/12/2021] [Accepted: 11/17/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND Levetiracetam (LEV, 5-100 mg/kg) has been shown to prevent audiogenic seizures in a dose-dependent manner. This chemical is known to bind to synaptic vesicle protein 2A and inhibit l-type calcium channels, affecting neurotransmitter release. We hypothesize that the drug prevents audiogenic seizures partially by affecting cochlear neural response. METHODS To test this hypothesis, rats were given 1000, 500, 50, or 0 mg/kg (saline control) LEV-injection. Distortion product otoacoustic emissions (DPOAE), reflecting outer hair cell (OHC) function, and cochlear compound action potentials (CAP), reflecting cochlear neural output, were recorded and compared pre- and post-LEV. RESULTS 1000 mg/kg LEV-injection did not significantly affect DPOAE. The high dose LEV-injection, however, significantly reduced CAP amplitude resulting threshold shift (TS), prolonged CAP latency, and enhanced CAP forward masking. CAP latency and forward masking were significantly affected at the 500 mg/kg dose, but CAP-TS remained unchanged after LEV-injection. Interestingly, CAP latency wassignificantly prolonged, at least at the low stimulation levels, although the amplitude of CAP remained constant after a clinical dose of LEV-injection (50 mg/kg). DISCUSSION Since the clinical dose of LEV-injection does not reduce CAP amplitude, the reduction of cochlear neural output is unlikely to be the underlying mechanism of LEV in the treatment of audiogenic seizure. The delayed cochlear neural response may be partially related to the prevention of audiogenic seizure. However, neuropharmacological changes in the central nervous system must play a major role in the treatment of audiogenic seizure, as it does in the treatment of focal epilepsy.
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Affiliation(s)
- Li Li
- Center for Hearing and Deafness, SUNY at Buffalo, Buffalo, NY 14214, USA
| | - Guang-Di Chen
- Center for Hearing and Deafness, SUNY at Buffalo, Buffalo, NY 14214, USA.
| | - Richard Salvi
- Center for Hearing and Deafness, SUNY at Buffalo, Buffalo, NY 14214, USA
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Eastman CL, Fender JS, Klein P, D'Ambrosio R. Therapeutic Effects of Time-Limited Treatment with Brivaracetam on Posttraumatic Epilepsy after Fluid Percussion Injury in the Rat. J Pharmacol Exp Ther 2021; 379:310-323. [PMID: 34593559 DOI: 10.1124/jpet.121.000585] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 09/28/2021] [Indexed: 11/22/2022] Open
Abstract
Mounting evidence suggests the synaptic vesicle glycoprotein 2A (SV2A) targeted by levetiracetam may contribute to epileptogenesis. Levetiracetam has shown anti-inflammatory, antioxidant, neuroprotective, and possible antiepileptogenic effects in brain injury and seizure/epilepsy models, and a phase 2 study has signaled a possible clinical antiepileptogenic effect. Brivaracetam shows greater affinity and specificity for SV2A than levetiracetam and broader preclinical antiseizure effects. Thus, we assessed the antiepileptogenic/disease-modifying potential of brivaracetam in an etiologically realistic rat posttraumatic epilepsy model optimized for efficient drug testing. Brivaracetam delivery protocols were designed to maintain clinical moderate-to-high plasma levels in young (5-week-old) male Sprague-Dawley rats for 4 weeks. Treatment protocols were rapidly screened in 4-week experiments using small groups of animals to ensure against rigorous testing of futile treatment protocols. The antiepileptogenic effects of brivaracetam treatment initiated 30 minutes, 4 hours, and 8 hours after rostral parasagittal fluid percussion injury (rpFPI) were then compared with vehicle-treated controls in a fully powered blind and randomized 16-week validation. Seizures were evaluated by video-electrocorticography using a 5-electrode epidural montage. Endpoint measures included incidence, frequency, duration, and spread of seizures. Group sizes and recording durations were supported by published power analyses. Three months after treatment ended, rats treated with brivaracetam starting at 4 hours post-FPI (the best-performing protocol) experienced a 38% decrease in overall incidence of seizures, 59% decrease in seizure frequency, 67% decrease in time spent seizing, and a 45% decrease in the proportion of spreading seizures that was independent of duration-based seizure definition. Thus, brivaracetam shows both antiepileptogenic and disease-modifying properties after rpFPI. SIGNIFICANCE STATEMENT: The rpFPI model, which likely incorporates epileptogenic mechanisms operating after human head injury, can be used to efficiently screen investigational treatment protocols and assess antiepileptogenic/disease-modifying effects. Our studies 1) support a role for SV2A in epileptogenesis, 2) suggest that brivaracetam and other drugs targeting SV2A should be considered for human clinical trials of prevention of post-traumatic epilepsy after head injury, and 3) provide data to inform the design of treatment protocols for clinical trials.
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Affiliation(s)
- Clifford L Eastman
- Department of Neurological Surgery, University of Washington, Seattle, Washington (C.L.E., J.S.F., R.D.); and Mid-Atlantic Epilepsy and Sleep Center, Bethesda, Maryland (P.K.)
| | - Jason S Fender
- Department of Neurological Surgery, University of Washington, Seattle, Washington (C.L.E., J.S.F., R.D.); and Mid-Atlantic Epilepsy and Sleep Center, Bethesda, Maryland (P.K.)
| | - Pavel Klein
- Department of Neurological Surgery, University of Washington, Seattle, Washington (C.L.E., J.S.F., R.D.); and Mid-Atlantic Epilepsy and Sleep Center, Bethesda, Maryland (P.K.)
| | - Raimondo D'Ambrosio
- Department of Neurological Surgery, University of Washington, Seattle, Washington (C.L.E., J.S.F., R.D.); and Mid-Atlantic Epilepsy and Sleep Center, Bethesda, Maryland (P.K.)
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Yang L, Afroz S, Valsamis HA, Michelson HB, Goodman JH, Ling DSF. Early intervention with levetiracetam prevents the development of cortical hyperexcitability and spontaneous epileptiform activity in two models of neurotrauma in rats. Exp Neurol 2020; 337:113571. [PMID: 33340499 DOI: 10.1016/j.expneurol.2020.113571] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 11/09/2020] [Accepted: 12/13/2020] [Indexed: 10/22/2022]
Abstract
This study examined the antiepileptogenic potential of the antiseizure drug (ASD) levetiracetam (LEV) using the in vitro traumatized-slice and in vivo controlled cortical impact (CCI) models of traumatic brain injury (TBI) in rats when administered early after the injury. For the in vitro model, acute coronal slices (400-450 μm) of rat neocortex (P21-32) were injured via a surgical cut that separated the superficial layers from the deeper regions. Persistent stimulus-evoked epileptiform activity developed within 1-2 h after trauma. In randomly selected slices, LEV (500 μM) was bath-applied for 1 h starting immediately or delayed by 30-80 min after injury. Treated and untreated slices were examined for epileptiform activity via intracellular and extracellular recordings. For the in vivo model, rats (P24-32) were subjected to a non-penetrating, focal, CCI injury targeting the neocortex (5.0 mm diameter; 2.0 mm depth). Immediately after injury, rats were given either a single dose of LEV (60-150 mg/kg, i.p.) or the saline vehicle. At 2-3 weeks after the injury, ex vivo cortical slices were examined for epileptiform activity. The results from the traumatized-slice experiments showed that in vitro treatment with LEV within 60 min of injury significantly reduced (> 50%) the proportion of slices that exhibited stimulus-evoked epileptiform activity. LEV treatment also increased the stimulus intensity required to trigger epileptiform bursts in injured slices by 2-4 fold. Consistent with these findings, LEV treatment of CCI-injured rats (n = 15) significantly reduced the proportion of animals that exhibited spontaneous and stimulus-evoked epileptiform bursts in ex vivo cortical slices compared to saline-treated controls (n = 15 rats), and also significantly increased the stimulus intensity required to evoke epileptiform bursts. These results suggest that early administration of LEV has the potential to prevent or reduce posttraumatic epileptogenesis and that there may be a narrow therapeutic window for successful prophylactic intervention.
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Affiliation(s)
- Lie Yang
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA; The Robert F. Furchgott Center for Behavioral and Neural Science, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA
| | - Sonia Afroz
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA; Program in Neural and Behavioral Science, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Brooklyn, NY 11203, USA; The Robert F. Furchgott Center for Behavioral and Neural Science, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA
| | - Helen A Valsamis
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA; Department of Neurology, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 1213, Brooklyn, NY 11203, USA; The Robert F. Furchgott Center for Behavioral and Neural Science, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA; Neurology Service, Kings County Hospital Center, Brooklyn, NY 11203, USA.
| | - Hillary B Michelson
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA; The Robert F. Furchgott Center for Behavioral and Neural Science, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA.
| | - Jeffrey H Goodman
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA; Department of Neurology, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 1213, Brooklyn, NY 11203, USA; The Robert F. Furchgott Center for Behavioral and Neural Science, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA; Department of Developmental Neurobiology, The New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA.
| | - Douglas S F Ling
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA; Program in Neural and Behavioral Science, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Brooklyn, NY 11203, USA; The Robert F. Furchgott Center for Behavioral and Neural Science, SUNY Downstate Health Sciences University, 450 Clarkson Ave., Box 29, Brooklyn, NY 11203, USA.
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Klein P, Friedman A, Hameed MQ, Kaminski RM, Bar-Klein G, Klitgaard H, Koepp M, Jozwiak S, Prince DA, Rotenberg A, Twyman R, Vezzani A, Wong M, Löscher W. Repurposed molecules for antiepileptogenesis: Missing an opportunity to prevent epilepsy? Epilepsia 2020; 61:359-386. [PMID: 32196665 PMCID: PMC8317585 DOI: 10.1111/epi.16450] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/26/2020] [Accepted: 01/27/2020] [Indexed: 12/11/2022]
Abstract
Prevention of epilepsy is a great unmet need. Acute central nervous system (CNS) insults such as traumatic brain injury (TBI), cerebrovascular accidents (CVA), and CNS infections account for 15%-20% of all epilepsy. Following TBI and CVA, there is a latency of days to years before epilepsy develops. This allows treatment to prevent or modify postinjury epilepsy. No such treatment exists. In animal models of acquired epilepsy, a number of medications in clinical use for diverse indications have been shown to have antiepileptogenic or disease-modifying effects, including medications with excellent side effect profiles. These include atorvastatin, ceftriaxone, losartan, isoflurane, N-acetylcysteine, and the antiseizure medications levetiracetam, brivaracetam, topiramate, gabapentin, pregabalin, vigabatrin, and eslicarbazepine acetate. In addition, there are preclinical antiepileptogenic data for anakinra, rapamycin, fingolimod, and erythropoietin, although these medications have potential for more serious side effects. However, except for vigabatrin, there have been almost no translation studies to prevent or modify epilepsy using these potentially "repurposable" medications. We may be missing an opportunity to develop preventive treatment for epilepsy by not evaluating these medications clinically. One reason for the lack of translation studies is that the preclinical data for most of these medications are disparate in terms of types of injury, models within different injury type, dosing, injury-treatment initiation latencies, treatment duration, and epilepsy outcome evaluation mode and duration. This makes it difficult to compare the relative strength of antiepileptogenic evidence across the molecules, and difficult to determine which drug(s) would be the best to evaluate clinically. Furthermore, most preclinical antiepileptogenic studies lack information needed for translation, such as dose-blood level relationship, brain target engagement, and dose-response, and many use treatment parameters that cannot be applied clinically, for example, treatment initiation before or at the time of injury and dosing higher than tolerated human equivalent dosing. Here, we review animal and human antiepileptogenic evidence for these medications. We highlight the gaps in our knowledge for each molecule that need to be filled in order to consider clinical translation, and we suggest a platform of preclinical antiepileptogenesis evaluation of potentially repurposable molecules or their combinations going forward.
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Affiliation(s)
- Pavel Klein
- Mid-Atlantic Epilepsy and Sleep Center, Bethesda, Maryland
| | - Alon Friedman
- Departments of Physiology and Cell Biology, and Brain and Cognitive Science, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Departments of Medical Neuroscience and Brain Repair Center, Dalhousie University, Halifax, Canada
| | - Mustafa Q. Hameed
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Rafal M. Kaminski
- Neurosymptomatic Domains Section, Roche Pharma Research & Early Development, Roche Innovation Center, Basel, Switzerland
| | - Guy Bar-Klein
- McKusick-Nathans Institute of Genetic Medicine, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Henrik Klitgaard
- Neurosciences Therapeutic Area, UCB Pharma, Braine-l’Alleud, Belgium
| | - Mathias Koepp
- Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, London, UK
| | - Sergiusz Jozwiak
- Department of Pediatric Neurology, Warsaw Medical University, Warsaw, Poland
| | - David A. Prince
- Neurology and the Neurological Sciences, Stanford University School of Medicine, Stanford, California
| | - Alexander Rotenberg
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Scientific Institute for Research and Health Care, Milan, Italy
| | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
- Center for Systems Neuroscience, Hannover, Germany
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Lévesque M, Ragsdale D, Avoli M. Evolving Mechanistic Concepts of Epileptiform Synchronization and their Relevance in Curing Focal Epileptic Disorders. Curr Neuropharmacol 2020; 17:830-842. [PMID: 30479217 PMCID: PMC7052840 DOI: 10.2174/1570159x17666181127124803] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 10/26/2018] [Accepted: 11/17/2018] [Indexed: 01/01/2023] Open
Abstract
The synchronized activity of neuronal networks under physiological conditions is mirrored by specific oscillatory patterns of the EEG that are associated with different behavioral states and cognitive functions. Excessive synchronization can, however, lead to focal epileptiform activity characterized by interictal and ictal discharges in epileptic patients and animal models. This review focusses on studies that have addressed epileptiform synchronization in temporal lobe regions by employing in vitro and in vivo recording techniques. First, we consider the role of ionotropic and metabotropic excitatory glutamatergic transmission in seizure generation as well as the paradoxical role of GABAA signaling in initiating and perhaps maintaining focal seizure activity. Second, we address non-synaptic mechanisms (which include voltage-gated ionic currents and gap junctions) in the generation of epileptiform synchronization. For each mechanism, we discuss the actions of antiepileptic drugs that are presumably modulating excitatory or inhibitory signaling and voltage-gated currents to prevent seizures in epileptic patients. These findings provide insights into the mechanisms of seizure initiation and maintenance, thus leading to the development of specific pharmacological treatments for focal epileptic disorders.
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Affiliation(s)
- Maxime Lévesque
- Montreal Neurological Institute, McGill University, Montreal, H3A 2B4 Quebec, Canada
| | - David Ragsdale
- Montreal Neurological Institute, McGill University, Montreal, H3A 2B4 Quebec, Canada
| | - Massimo Avoli
- Montreal Neurological Institute, McGill University, Montreal, H3A 2B4 Quebec, Canada.,Departments of Neurology & Neurosurgery, and of Physiology, McGill University, Montréal, H3A 2B4 Québec, Canada.,Department of Experimental Medicine, Facoltà di Medicina e Odontoiatria, Sapienza University of Rome, 00185 Roma, Italy
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Leo A, Caro CD, Nesci V, Palma E, Tallarico M, Iannone M, Constanti A, Sarro GD, Russo E, Citraro R. Antiepileptogenic effects of Ethosuximide and Levetiracetam in WAG/Rij rats are only temporary. Pharmacol Rep 2019; 71:833-838. [PMID: 31386986 DOI: 10.1016/j.pharep.2019.04.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 03/22/2019] [Accepted: 04/23/2019] [Indexed: 11/08/2022]
Abstract
BACKGROUND WAG/Rij rats represent a validated genetic animal model of epileptogenesis, absence epilepsy and depressive-like comorbidity. Some treatments (e.g. ethosuximide), using specific protocols, prevent the development of spontaneous absence seizures. Accordingly, ethosuximide increases remission occurrence in children with childhood absence epilepsy in comparison to valproic acid. Considering that in this animal model, antiepileptogenic effects are, in some cases, not retained over time, we studied whether the antiepileptogenic effects of both ethosuximide and levetiracetam (which also possesses antiepileptogenic effects in this and other animal epilepsy models) would be retained 5 months after drug suspension. METHODS WAG/Rij rats of ˜1 month of age were treated long-term with one of the two drugs at a dose of ˜80 mg/kg/day for 17 consecutive weeks; 1 and 5 months after drug suspension, the development of absence seizures as well as depressive-like behaviour were assessed by EEG recordings and the forced swimming test (FST). RESULTS In agreement with a previous report, both drugs continued to show antiepileptogenic effects 1 month after their discontinuation. Furthermore, ethosuximide improved depressive-like behaviour, whereas in contrast, levetiracetam worsened this symptom. However, none of the drugs maintained their antiepileptogenic effects 5 months after suspension, and in addition, animal behaviour in the FST returned to control conditions. CONCLUSION Overall, these results demonstrate that the antiepileptogenic effects of both ethosuximide and levetiracetam on absence seizure development and associated depressive-like behaviour in this model are only temporary.
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Affiliation(s)
- Antonio Leo
- University of Catanzaro, School of Medicine, Science of Health Department, Catanzaro, Italy
| | - Carmen De Caro
- University of Catanzaro, School of Medicine, Science of Health Department, Catanzaro, Italy
| | - Valentina Nesci
- University of Catanzaro, School of Medicine, Science of Health Department, Catanzaro, Italy
| | - Ernesto Palma
- University of Catanzaro, School of Medicine, Science of Health Department, Catanzaro, Italy
| | - Martina Tallarico
- University of Catanzaro, School of Medicine, Science of Health Department, Catanzaro, Italy; CNR, Institute of Neurological Sciences, Pharmacology Section, Roccelletta di Borgia, Catanzaro, Italy
| | - Michelangelo Iannone
- CNR, Institute of Neurological Sciences, Pharmacology Section, Roccelletta di Borgia, Catanzaro, Italy
| | | | | | - Emilio Russo
- University of Catanzaro, School of Medicine, Science of Health Department, Catanzaro, Italy
| | - Rita Citraro
- University of Catanzaro, School of Medicine, Science of Health Department, Catanzaro, Italy.
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11
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Pietrzak B, Natanek A, Zwierzyńska E. Levetiracetam – a drug that can be used not only in the treatment of epilepsy. POSTEP HIG MED DOSW 2019. [DOI: 10.5604/01.3001.0013.4670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Levetiracetam, which belongs to the new generation of antiepileptic drugs, has a unique and not well-known mechanism of action. The drug affects the release of neurotransmitters through the binding to the synaptic vesicle protein SV2A. Moreover, it acts on calcium channels, inhibits glutamatergic neurotransmission and affects GABA-ergic neurotransmission through e.g. the Zn²⁺-induced suppression of GABAA-mediated presynaptic inhibition and the modulation of the action of GABAA antagonists. Levetiracetam has also neuroprotective activity which is associated with the influence on transcription processes, neurotransmission, antioxidant and anti-inflammatory activity. The results of recent research indicate that this complex action creates the prospect of using it in the alleviation of epileptogenesis, poststroke seizuires, seizure prophylaxis in brain injured patients and diabetic neuropathy. Furthermore, the drug may also have a beneficial effect in the treatment of Alzheimer patients with epileptic seizures and levodopa-induced dyskinesias in Parkinson’s disease.
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Affiliation(s)
- Bogusława Pietrzak
- Zakład Farmakodynamiki Katedry Biofarmacji Uniwersytetu Medycznego w Łodzi
| | - Alicja Natanek
- Zakład Farmakodynamiki Katedry Biofarmacji Uniwersytetu Medycznego w Łodzi
| | - Ewa Zwierzyńska
- Zakład Farmakodynamiki Katedry Biofarmacji Uniwersytetu Medycznego w Łodzi
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12
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de Souza AG, Chaves Filho AJM, Souza Oliveira JV, de Souza DAA, Lopes IS, de Carvalho MAJ, de Lima KA, Florenço Sousa FC, Mendes Vasconcelos SM, Macedo D, de França Fonteles MM. Prevention of pentylenetetrazole-induced kindling and behavioral comorbidities in mice by levetiracetam combined with the GLP-1 agonist liraglutide: Involvement of brain antioxidant and BDNF upregulating properties. Biomed Pharmacother 2019; 109:429-439. [DOI: 10.1016/j.biopha.2018.10.066] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/12/2018] [Accepted: 10/12/2018] [Indexed: 12/24/2022] Open
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13
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Chen D, Xing H, Jiang Q, Xiang Y, Hu W, Guo H. Role of Levetiracetam in the Rehabilitation of Dysphagia due to Stroke. INT J PHARMACOL 2017. [DOI: 10.3923/ijp.2017.603.611] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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14
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Vinogradova LV. Audiogenic kindling and secondary subcortico-cortical epileptogenesis: Behavioral correlates and electrographic features. Epilepsy Behav 2017; 71:142-153. [PMID: 26148984 DOI: 10.1016/j.yebeh.2015.06.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 06/05/2015] [Accepted: 06/06/2015] [Indexed: 01/14/2023]
Abstract
Human epilepsy is usually considered to result from cortical pathology, but animal studies show that the cortex may be secondarily involved in epileptogenesis, and cortical seizures may be triggered by extracortical mechanisms. In the audiogenic kindling model, recurrent subcortical (brainstem-driven) seizures induce secondary epileptic activation of the cortex. The present review focuses on behavioral and electrographic features of the subcortico-cortical epileptogenesis: (1) behavioral expressions of traditional and mild paradigms of audiogenic kindling produced by full-blown (generalized) and minimal (focal) audiogenic seizures, respectively; (2) electrographic manifestations of secondary epileptic activation of the cortex - cortical epileptic discharge and cortical spreading depression; and (3) persistent individual asymmetry of minimal audiogenic seizures and secondary cortical events produced by their repetition. The characteristics of audiogenic kindling suggest that this model represents a unique experimental approach to studying cortical epileptogenesis and network aspects of epilepsy. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic".
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Affiliation(s)
- Lyudmila V Vinogradova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
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15
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Tanaka T, Ihara M. Post-stroke epilepsy. Neurochem Int 2017; 107:219-228. [PMID: 28202284 DOI: 10.1016/j.neuint.2017.02.002] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 02/05/2017] [Accepted: 02/06/2017] [Indexed: 01/17/2023]
Abstract
Post-stroke epilepsy (PSE) is a common complication after stroke, yet treatment options remain limited. While many physicians prescribe antiepileptic drugs (AED) for secondary prevention of PSE, it is unclear which treatments are most effective in the prevention of recurrence of symptoms, or whether such therapy is needed for primary prevention. This review discusses the current understanding of epidemiology, diagnoses, mechanisms, risk factors, and treatments of PSE.
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Affiliation(s)
- Tomotaka Tanaka
- Department of Neurology, National Cerebral and Cardiovascular Center, Osaka, Japan.
| | - Masafumi Ihara
- Department of Neurology, National Cerebral and Cardiovascular Center, Osaka, Japan
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16
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Ge YX, Tian XZ, Lin YY, Liu XY. Chronic treatment with levetiracetam reverses deficits in hippocampal LTP in vivo in experimental temporal lobe epilepsy rats. Neurosci Lett 2016; 628:194-200. [PMID: 27345386 DOI: 10.1016/j.neulet.2016.06.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2016] [Revised: 06/10/2016] [Accepted: 06/21/2016] [Indexed: 12/21/2022]
Abstract
Temporal lobe epilepsy (TLE), the common form of epilepsy in adults, often displays complex partial seizures and cognitive deficits. The underlying mechanisms of such deficits are not yet well understood. Many contributing factors, such as initial epileptogenic lesion, seizure type, age of onset, and treatment side effects have been proposed. Levetiracetam (LEV) is a novel anti-epileptic drug (AED) used to treat partial seizures and idiopathic generalized epilepsy. It has been suggested that LEV exerts antiepileptic properties by modulation of synaptic release of neurotransmitters. However, its neuroprotective effects on learning and memory are not yet well demonstrated. Here we showed the impairment of spatial memory in the pilocarpine-induced experimental TLE rats, which can be improved by LEV. Furthermore, we found chronic LEV treatment partially reversed the SE-induced synaptic dysfunction in hippocampal LTP induction in vivo. In addition, LEV treatment can alleviate the SE-induced abnormal GluR1 phosphorylation at Ser(831) site, which may contribute to the rescue of synaptic transmission. These results indicate the neuroprotective role for LEV while it exhibits an antiseizure effect on experimental epileptic models.
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Affiliation(s)
- Yu-Xing Ge
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China
| | - Xiang-Zhu Tian
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China
| | - Ying-Ying Lin
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China
| | - Xue-Yuan Liu
- Department of Neurology, Tongji University Affiliated Tenth People's Hospital, 200072 Shanghai, PR China.
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17
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Cunha AOS, de Oliveira JAC, Almeida SS, Garcia-Cairasco N, Leão RM. Inhibition of long-term potentiation in the schaffer-CA1 pathway by repetitive high-intensity sound stimulation. Neuroscience 2015; 310:114-27. [PMID: 26391920 DOI: 10.1016/j.neuroscience.2015.09.040] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 09/01/2015] [Accepted: 09/14/2015] [Indexed: 10/23/2022]
Abstract
High-intensity sound can induce seizures in susceptible animals. After repeated acoustic stimuli changes in behavioural seizure repertoire and epileptic EEG activity might be seen in recruited limbic and forebrain structures, a phenomenon known as audiogenic kindling. It is postulated that audiogenic kindling can produce synaptic plasticity events leading to the spread of epileptogenic activity to the limbic system. In order to test this hypothesis, we investigated if long-term potentiation (LTP) of hippocampal Schaffer-CA1 synapses and spatial navigation memory are altered by a repeated high-intensity sound stimulation (HISS) protocol, consisting of one-minute 120 dB broadband noise applied twice a day for 10 days, in normal Wistar rats and in audiogenic seizure-prone rats (Wistar Audiogenic Rats - WARs). After HISS all WARs exhibited midbrain seizures and 50% of these animals developed limbic recruitment, while only 26% of Wistar rats presented midbrain seizures and none of them had limbic recruitment. In naïve animals, LTP in hippocampal CA1 neurons was induced by 50- or 100-Hz high-frequency stimulation of Schaffer fibres in slices from both Wistar and WAR animals similarly. Surprisingly, HISS suppressed LTP in CA1 neurons in slices from Wistar rats that did not present any seizure, and inhibited LTP in slices from Wistar rats with only midbrain seizures. However HISS had no effect on LTP in CA1 neurons from slices of WARs. Interestingly HISS did not alter spatial navigation and memory in both strains. These findings show that repeated high-intensity sound stimulation prevent LTP of Schaffer-CA1 synapses from Wistar rats, without affecting spatial memory. This effect was not seen in hippocampi from audiogenic seizure-prone WARs. In WARs the link between auditory stimulation and hippocampal LTP seems to be disrupted which could be relevant for the susceptibility to seizures in this strain.
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Affiliation(s)
- A O S Cunha
- Department of Physiology, FMRP, University of São Paulo, Ribeirão Preto-SP, Brazil
| | - J A C de Oliveira
- Department of Physiology, FMRP, University of São Paulo, Ribeirão Preto-SP, Brazil
| | - S S Almeida
- Departament of Psychology, FFCLRP, University of São Paulo, Ribeirão Preto-SP, Brazil
| | - N Garcia-Cairasco
- Department of Physiology, FMRP, University of São Paulo, Ribeirão Preto-SP, Brazil.
| | - R M Leão
- Department of Physiology, FMRP, University of São Paulo, Ribeirão Preto-SP, Brazil.
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18
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Additive interaction of levetiracetam with lamotrigine in the mouse 6 Hz psychomotor seizure model – an isobolographic analysis. CURRENT ISSUES IN PHARMACY AND MEDICAL SCIENCES 2015. [DOI: 10.12923/j.2084-980x/26.1/a.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
The aim of this study was to characterize the anticonvulsant effects of levetiracetam (LEV) in combination with lamotrigine (LTG – a second-generation antiepileptic drug), in the mouse 6 Hz psychomotor seizure model. Limbic (psychomotor) seizure activity was evoked in albino Swiss mice by a current (32 mA, 6 Hz, 3 s stimulus duration) delivered via ocular electrodes and isobolographic analysis for parallel dose-response relationship curves (DRRCs) was used to characterize the consequent anticonvulsant interactions between the drug combinations. Results indicated that LEV administered singly was associated with a DRRC that was parallel to that for LTG. With isobolography for parallel DRRCs, the combination of LEV with LTG at three fixed-ratios of 1:3, 1:1 and 3:1 exerted additive interaction. LEV combined with LTG exerted additive interaction in the mouse 6 Hz psychomotor seizure model.
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19
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Vinogradova LV, van Rijn CM. Long-term disease-modifying effect of the endocannabinoid agonist WIN55,212-2 in a rat model of audiogenic epilepsy. Pharmacol Rep 2014; 67:501-3. [PMID: 25933961 DOI: 10.1016/j.pharep.2014.12.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 11/28/2014] [Accepted: 12/03/2014] [Indexed: 11/26/2022]
Abstract
BACKGROUND Modulation of the endocannabinoid (eCB) transmission is a promising approach to treating epilepsy. Animal models can be used to investigate this approach. Krushinsky-Molodkina (KM) rats have, genetically, audiogenic epilepsy. Moreover, in these animals, repeated induction of audiogenic seizures results in a progressive prolongation of the seizures, known as audiogenic kindling. METHODS The present study evaluated, in these KM rats, acute and long-term effects of a single dose of 4 mg/kg of the cannabinoid-receptor agonist WIN55,212-2. RESULTS Administration of the single dose of WIN55,212-2 one hour before the 4th seizure delayed the kindling process by two weeks, without any acute effect on the audiogenic seizures. CONCLUSIONS This result suggests that short-term potentiation of the eCB system might modify the epileptogenic disease process in patients with a progressive course of epilepsy.
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Affiliation(s)
- Lyudmila V Vinogradova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
| | - Clementina M van Rijn
- Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, The Netherlands.
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20
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Lévesque M, Behr C, Avoli M. The anti-ictogenic effects of levetiracetam are mirrored by interictal spiking and high-frequency oscillation changes in a model of temporal lobe epilepsy. Seizure 2014; 25:18-25. [PMID: 25645630 DOI: 10.1016/j.seizure.2014.11.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 11/18/2014] [Accepted: 11/20/2014] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Mesial temporal lobe epilepsy (MTLE) is the most prevalent type of partial epileptic disorders. In this study, we have analyzed the impact of levetiracetam (LEV) in the pilocarpine model of MTLE. METHODS Sprague-Dawley rats (n=19) were injected with pilocarpine (380 mg/kg, i.p.) to induce a status epilepticus. Twelve animals were used as controls and seven were treated with LEV. They were implanted with bipolar electrodes in the CA3 subfield of the hippocampus, entorhinal cortex (EC), dentate gyrus (DG) and subiculum and EEG-video monitored continuously from day 4 to day 14 after SE. RESULTS Only 29% of LEV-treated animals had seizures compared to all controls following a latent period that was similar in duration. Seizure rates were lower in LEV-treated animals. In LEV-treated animals without seizures, lower interictal spike rates were found in all regions compared to controls. Analysis of interictal high-frequency oscillations (HFO s) revealed that LEV-treated animals without seizures had lower rates of interictal spikes with ripples (80-200 Hz) in CA3, EC and subiculum (p<0.01), whereas rates of interictal spikes with fast ripples (250-500 Hz) were significantly lower in CA3 and subiculum, compared to controls. CONCLUSION Our findings indicate that the anti-ictogenic properties of LEV are mirrored by decreases of interictal spike rate in temporal lobe regions, and are accompanied by subregion-specific decreases of HFO occurrence in CA3 and subiculum. Overall, this evidence suggest that LEV may inhibit neural network activity in regions that are known to play important roles in MTLE.
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Affiliation(s)
- Maxime Lévesque
- Montreal Neurological Institute and Department of Neurology & Neurosurgery, McGill University, Montréal, Qc H3A 2B4, Canada
| | - Charles Behr
- Montreal Neurological Institute and Department of Neurology & Neurosurgery, McGill University, Montréal, Qc H3A 2B4, Canada
| | - Massimo Avoli
- Montreal Neurological Institute and Department of Neurology & Neurosurgery, McGill University, Montréal, Qc H3A 2B4, Canada.
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21
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Glazova MV, Nikitina LS, Hudik KA, Kirillova OD, Dorofeeva NA, Korotkov AA, Chernigovskaya EV. Inhibition of ERK1/2 signaling prevents epileptiform behavior in rats prone to audiogenic seizures. J Neurochem 2014; 132:218-29. [PMID: 25351927 DOI: 10.1111/jnc.12982] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 10/14/2014] [Accepted: 10/22/2014] [Indexed: 01/24/2023]
Abstract
It has recently been proposed that extracellular signal-regulated kinases 1 and 2 (ERK1/2) are one of the factors mediating seizure development. We hypothesized that inhibition of ERK1/2 activity could prevent audiogenic seizures by altering GABA and glutamate release mechanisms. Krushinsky-Molodkina rats, genetically prone to audiogenic seizure, were recruited in the experiments. Animals were i.p. injected with an inhibitor of ERK1/2 SL 327 at different doses 60 min before audio stimulation. We demonstrated for the first time that inhibition of ERK1/2 activity by SL 327 injections prevented seizure behavior and this effect was dose-dependent and correlated with ERK1/2 activity. The obtained data also demonstrated unchanged levels of GABA production, and an increase in the level of vesicular glutamate transporter 2. The study of exocytosis protein expression showed that SL 327 treatment leads to downregulation of vesicle-associated membrane protein 2 and synapsin I, and accumulation of synaptosomal-associated protein 25 (SNAP-25). The obtained data indicate that the inhibition of ERK1/2 blocks seizure behavior presumably by altering the exocytosis machinery, and identifies ERK1/2 as a potential target for the development of new strategies for seizure treatment. Extracellular signal-regulated kinases 1 and 2 (ERK1/2) are one of the factors mediating seizure development. Here we report that inhibition of ERK1/2 by SL 327 prevented seizure behavior and this effect was dose-dependent and correlated with ERK1/2 activity. Accumulation of VGLUT2 was associated with differential changing of synaptic proteins VAMP2, SNAP-25 and synapsin I. The obtained data indicate that the inhibition of ERK1/2 alters neurotransmitter release by changing the exocytosis machinery, thus preventing seizures.
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Affiliation(s)
- Margarita V Glazova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Saint-Petersburg, Russia
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Kaminski RM, Rogawski MA, Klitgaard H. The potential of antiseizure drugs and agents that act on novel molecular targets as antiepileptogenic treatments. Neurotherapeutics 2014; 11:385-400. [PMID: 24671870 PMCID: PMC3996125 DOI: 10.1007/s13311-014-0266-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
A major goal of contemporary epilepsy research is the identification of therapies to prevent the development of recurrent seizures in individuals at risk, including those with brain injuries, infections, or neoplasms; status epilepticus; cortical dysplasias; or genetic epilepsy susceptibility. In this review we consider the evidence largely from preclinical models for the antiepileptogenic activity of a diverse range of potential therapies, including some marketed antiseizure drugs, as well as agents that act by immune and inflammatory mechanisms; reduction of oxidative stress; activation of the mammalian target of rapamycin or peroxisome proliferator-activated receptors γ pathways; effects on factors related to thrombolysis, hematopoesis, and angiogenesis; inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A reducatase; brain-derived neurotrophic factor signaling; and blockade of α2 adrenergic and cannabinoid receptors. Antiepileptogenesis refers to a therapy of which the beneficial action is to reduce seizure frequency or severity outlasting the treatment period. To date, clinical trials have failed to demonstrate that antiseizure drugs have such disease-modifying activity. However, studies in animal models with levetiracetam and ethosuximide are encouraging, and clinical trials with these agents are warranted. Other promising strategies are inhibition of interleukin 1β signaling by drugs such as VX-765; modulation of sphingosine 1-phosphate signaling by drugs such as fingolimod; activation of the mammalian target of rapamycin by drugs such as rapamycin; the hormone erythropoietin; and, paradoxically, drugs such as the α2 adrenergic receptor antagonist atipamezole and the CB1 cannabinoid antagonist SR141716A (rimonabant) with proexcitatory activity. These approaches could lead to a new paradigm in epilepsy drug therapy where treatment for a limited period prevents the occurrence of spontaneous seizures, thus avoiding lifelong commitment to symptomatic treatment.
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Affiliation(s)
| | - Michael A. Rogawski
- />Department of Neurology, University of California, Davis School of Medicine, Sacramento, CA USA
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23
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Cuomo O, Rispoli V, Leo A, Politi GB, Vinciguerra A, di Renzo G, Cataldi M. The antiepileptic drug levetiracetam suppresses non-convulsive seizure activity and reduces ischemic brain damage in rats subjected to permanent middle cerebral artery occlusion. PLoS One 2013; 8:e80852. [PMID: 24236205 PMCID: PMC3827478 DOI: 10.1371/journal.pone.0080852] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 10/11/2013] [Indexed: 02/06/2023] Open
Abstract
The antiepileptic drug Levetiracetam (Lev) has neuroprotective properties in experimental stroke, cerebral hemorrhage and neurotrauma. In these conditions, non-convulsive seizures (NCSs) propagate from the core of the focal lesion into perilesional tissue, enlarging the damaged area and promoting epileptogenesis. Here, we explore whether Lev neuroprotective effect is accompanied by changes in NCS generation or propagation. In particular, we performed continuous EEG recordings before and after the permanent occlusion of the middle cerebral artery (pMCAO) in rats that received Lev (100 mg/kg) or its vehicle immediately before surgery. Both in Lev-treated and in control rats, EEG activity was suppressed after pMCAO. In control but not in Lev-treated rats, EEG activity reappeared approximately 30-45 min after pMCAO. It initially consisted in single spikes and, then, evolved into spike-and-wave and polyspike-and-wave discharges. In Lev-treated rats, only rare spike events were observed and the EEG power was significantly smaller than in controls. Approximately 24 hours after pMCAO, EEG activity increased in Lev-treated rats because of the appearance of polyspike events whose power was, however, significantly smaller than in controls. In rats sacrificed 24 hours after pMCAO, the ischemic lesion was approximately 50% smaller in Lev-treated than in control rats. A similar neuroprotection was observed in rats sacrificed 72 hours after pMCAO. In conclusion, in rats subjected to pMCAO, a single Lev injection suppresses NCS occurrence for at least 24 hours. This electrophysiological effect could explain the long lasting reduction of ischemic brain damage caused by this drug.
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Affiliation(s)
- Ornella Cuomo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, Federico II University of Naples, Naples, Italy
| | - Vincenzo Rispoli
- Department of Health Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
| | - Antonio Leo
- Department of Health Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
| | - Giovanni Bosco Politi
- Department of Health Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
| | - Antonio Vinciguerra
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, Federico II University of Naples, Naples, Italy
| | - Gianfranco di Renzo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, Federico II University of Naples, Naples, Italy
| | - Mauro Cataldi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, Federico II University of Naples, Naples, Italy
- * E-mail:
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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.
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Affiliation(s)
- Gilles van Luijtelaar
- Donders Centre for Cognition, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands.
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Abstract
BACKGROUND Neonatal seizures can result in chronic epilepsy and long-term behavioral and cognitive deficits. Levetiracetam (LEV), an antiepileptic drug that binds to the synaptic vesicle protein 2A (SV2A), has been increasingly used off-label for the therapy of neonatal seizures. Preclinical data regarding the acute or long-term efficacy of LEV are lacking. METHODS We tested the anticonvulsant efficacy of LEV in a rat model of hypoxia-induced neonatal seizures. In addition, we evaluated the protective effects of postnatal day (P)10 LEV treatment on later-life kainic acid (KA)-induced seizure susceptibility and seizure-induced neuronal injury. Western blot and immunohistochemistry were used to assess the developmental regulation of SV2A in the rat and human brain. RESULTS LEV pretreatment at P10 significantly decreased the cumulative duration of behavioral and electrographic seizures at both 25 and 50 mg/kg. At P40, KA-induced seizures and neuronal loss were significantly diminished in rats previously treated with LEV. LEV target SV2A is present in both neonatal rat and human brain and increases steadily to adulthood. CONCLUSION LEV suppressed acute seizures induced by perinatal hypoxia and diminished later-life seizure susceptibility and seizure-induced neuronal injury, providing evidence for disease modification. These results support consideration of a clinical trial of LEV in neonatal seizures.
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Sugata S, Hanaya R, Kumafuji K, Tokudome M, Serikawa T, Kurisu K, Arita K, Sasa M. Neuroprotective effect of levetiracetam on hippocampal sclerosis-like change in spontaneously epileptic rats. Brain Res Bull 2011; 86:36-41. [DOI: 10.1016/j.brainresbull.2011.05.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 05/16/2011] [Accepted: 05/30/2011] [Indexed: 10/18/2022]
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Pro-epileptic effects of the cannabinoid receptor antagonist SR141716 in a model of audiogenic epilepsy. Epilepsy Res 2011; 96:250-6. [PMID: 21733658 DOI: 10.1016/j.eplepsyres.2011.06.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 06/09/2011] [Accepted: 06/11/2011] [Indexed: 01/06/2023]
Abstract
Endocannabinoid system and its CB1 receptors are suggested to provide endogeneous protection against seizures. The present study examines whether CB1 receptors contribute to resistance to seizures and kindling epileptogenesis in a model of audiogenic epilepsy. Three groups of Wistar rats were used: rats unsusceptible to audiogenic seizures, rats with acquired resistance to audiogenic seizures and rats with reproducible audiogenic running seizures. Chronic treatment with the CB1 receptor antagonist SR141716 (5 daily dosing of 30mg/kg) did not change innate resistance to audiogenic seizures in non-epileptic rats but reverted acquired seizure resistance in rats which lost their epileptic sensitivity with repeated testing. In the latter rats, audiogenic running seizures reappeared for at least two weeks after the end of treatment. In rats with reproducible seizure response, acutely, SR lengthened audiogenic seizures due to prolongation or appearance, de novo, of post-running limbic clonus without any effect on running seizure per se. This limbic component mimicked audiogenic kindling and indicated propagation of sound-induced brainstem seizure to the limbic forebrain. After chronic SR administration the incidence of the limbic clonus remained to be increased for at least two weeks. The present study supports the hypothesis about a role of CB1 receptors in endogeneous anticonvulsive mechanisms of the brain.
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van Tuijl J, van Raak E, de Krom M, Lodder J, Aldenkamp A. Early treatment after stroke for the prevention of late epileptic seizures: A report on the problems performing a randomised placebo-controlled double-blind trial aimed at anti-epileptogenesis. Seizure 2011; 20:285-91. [DOI: 10.1016/j.seizure.2010.12.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2010] [Revised: 11/22/2010] [Accepted: 12/27/2010] [Indexed: 10/18/2022] Open
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Vinogradova LV. Interhemispheric difference in susceptibility to epileptogenesis: evidence from the audiogenic kindling model in Wistar rats. Brain Res 2010; 1329:175-81. [PMID: 20303340 DOI: 10.1016/j.brainres.2010.03.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 03/10/2010] [Accepted: 03/11/2010] [Indexed: 10/19/2022]
Abstract
Audiogenic kindling (AK) represents a model of naturally occurring epileptogenesis in which intensification of repeatedly induced audiogenic seizures results from propagation of epileptic activity from the brainstem to forebrain. Previously it has been shown that unilateral cortical spreading depression (SD) is a reliable earliest manifestation of mild AK produced by repetition of minimal audiogenic seizures (running) in Wistar rats. The unilateral triggering SD suggests the existence of asymmetry in the forebrain recruitment during the kindling and the present study examined whether epileptogenesis produced by this mild AK paradigm is a lateralized process. Twenty five running episodes were induced by brief sound stimulation in Wistar rats susceptible to audiogenic seizures. Behavioral and EEG correlates of AK development were assessed. Running behavior elicited by brief sound stimulation had an asymmetrical pattern with profound preference for one direction. Most rats expressing leftward running displayed full kindling development whereas the majority of rats with rightward running were resistant to AK. The EEG marker of AK, a cortical epileptiform discharge, was recorded only in rats with leftward running and the first discharge appeared in the left cortex. Cortical SD was recorded after repeated running seizures in all rats with reproducible audiogenic response irrespective of the running lateralization and propensity to kindling. Until the late kindling stages, SD was triggered unilaterally in the cortex ipsilateral to the running direction. These findings indicate intrinsically determined lateralization of epileptogenic process in the mild AK model and enhanced vulnerability of the left hemisphere to epileptogenesis.
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Affiliation(s)
- Lyudmila V Vinogradova
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerova Street 5A, Moscow 117485, Russia.
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Dudra-Jastrzebska M, Andres-Mach MM, Ratnaraj N, Patsalos PN, Czuczwar SJ, Luszczki JJ. Isobolographic characterization of the anticonvulsant interaction profiles of levetiracetam in combination with clonazepam, ethosuximide, phenobarbital and valproate in the mouse pentylenetetrazole-induced seizure model. Seizure 2009; 18:607-14. [PMID: 19628415 DOI: 10.1016/j.seizure.2009.06.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 05/13/2009] [Accepted: 06/25/2009] [Indexed: 11/25/2022] Open
Abstract
This study was designed so as to characterize the interactions between levetiracetam (LEV) and the conventional antiepileptic drugs (AEDs) clonazepam (CZP), ethosuximide (ETS), phenobarbital (PB), and valproate (VPA) in suppressing pentylenetetrazole (PTZ)-induced clonic seizures in mice by use of type II isobolographic analysis. Adverse-effect profiles of the drugs in combination were determined and brain AED concentrations were measured. The combinations of VPA and ETS with LEV at the fixed-ratio of 1:2, CZP with LEV (1:20,000), and PB with LEV (1:20) were supra-additive (synergistic) in suppressing seizures. In contrast, VPA and ETS with LEV (1:1, 2:1, and 4:1), CZP with LEV (1:1000, 1:5000, and 1:10,000), and PB with LEV (1:1, 1:5, and 1:10) were additive. No adverse effects were observed. ETS significantly reduced brain LEV concentrations but no other pharmacokinetic changes were observed. The combinations of CZP with LEV (1:20,000); VPA and ETS with LEV (1:2); and PB with LEV (1:20) appear to be favorable combinations exerting supra-additive interactions in suppressing PTZ-induced seizures.
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Affiliation(s)
- Monika Dudra-Jastrzebska
- Department of Pathophysiology, Medical University of Lublin, Jaczewskiego 8, PL 20-090 Lublin, Poland
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Wojda E, Wlaz A, Patsalos PN, Luszczki JJ. Isobolographic characterization of interactions of levetiracetam with the various antiepileptic drugs in the mouse 6 Hz psychomotor seizure model. Epilepsy Res 2009; 86:163-74. [PMID: 19596559 DOI: 10.1016/j.eplepsyres.2009.06.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 06/08/2009] [Accepted: 06/11/2009] [Indexed: 10/20/2022]
Abstract
The aim of this study was to characterize the anticonvulsant effects of levetiracetam (LEV) in combination with the various antiepileptic drugs (clonazepam [CZP], oxcarbazepine [OXC], phenobarbital [PB], tiagabine [TGB], and valproate [VPA]), in the mouse 6 Hz psychomotor seizure model. Limbic (psychomotor) seizure activity was evoked in albino Swiss mice by a current (32 mA, 6 Hz, 3s stimulus duration) delivered via ocular electrodes and isobolographic analysis for parallel and non-parallel dose-response effects was used to characterize the consequent anticonvulsant interactions between the various drug combinations. Potential concurrent adverse-effect profiles of interactions between LEV and CZP, OXC, PB, TGB, and VPA at the fixed-ratio of 1:1 were evaluated in the chimney (motor performance), passive avoidance (long-term memory), and grip-strength (muscular strength) tests. LEV administered singly was associated with a dose-response relationship curve (DRRC) that was parallel to that for CZP and non-parallel to that for OXC, PB, TGB and VPA. With isobolography for parallel DRRCs, the combination of LEV with CZP at three fixed-ratios of 1:3, 1:1 and 3:1 was additive in nature. With isobolography for non-parallel DRRCs the combinations of LEV with OXC, TGB and VPA at the fixed-ratio of 1:1 were also additive. In contrast, the isobolography for non-parallel DRRCs revealed that the interaction for the combination of LEV with PB at the fixed-ratio of 1:1 was supra-additive (synergistic). None of the combinations were associated with any concurrent adverse effects with regards to motor coordination, long-term memory or muscular strength. LEV is associated with favorable anticonvulsant synergism with PB and is additive with regards to CZP, OXC, TGB and VPA in the mouse 6 Hz psychomotor seizure model.
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Affiliation(s)
- Ewa Wojda
- Department of Pathophysiology, Medical University, Jaczewskiego 8, PL 20-090 Lublin, Poland
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A Drosophila systems model of pentylenetetrazole induced locomotor plasticity responsive to antiepileptic drugs. BMC SYSTEMS BIOLOGY 2009; 3:11. [PMID: 19154620 PMCID: PMC2657775 DOI: 10.1186/1752-0509-3-11] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 01/21/2009] [Indexed: 11/21/2022]
Abstract
Background Rodent kindling induced by PTZ is a widely used model of epileptogenesis and AED testing. Overlapping pathophysiological mechanisms may underlie epileptogenesis and other neuropsychiatric conditions. Besides epilepsy, AEDs are widely used in treating various neuropsychiatric disorders. Mechanisms of AEDs' long term action in these disorders are poorly understood. We describe here a Drosophila systems model of PTZ induced locomotor plasticity that is responsive to AEDs. Results We empirically determined a regime in which seven days of PTZ treatment and seven days of subsequent PTZ discontinuation respectively cause a decrease and an increase in climbing speed of Drosophila adults. Concomitant treatment with NaVP and LEV, not ETH, GBP and VGB, suppressed the development of locomotor deficit at the end of chronic PTZ phase. Concomitant LEV also ameliorated locomotor alteration that develops after PTZ withdrawal. Time series of microarray expression profiles of heads of flies treated with PTZ for 12 hrs (beginning phase), two days (latent phase) and seven days (behaviorally expressive phase) showed only down-, not up-, regulation of genes; expression of 23, 2439 and 265 genes were downregulated, in that order. GO biological process enrichment analysis showed downregulation of transcription, neuron morphogenesis during differentiation, synaptic transmission, regulation of neurotransmitter levels, neurogenesis, axonogenesis, protein modification, axon guidance, actin filament organization etc. in the latent phase and of glutamate metabolism, cell communication etc. in the expressive phase. Proteomic interactome based analysis provided further directionality to these events. Pathway overrepresentation analysis showed enrichment of Wnt signaling and other associated pathways in genes downregulated by PTZ. Mining of available transcriptomic and proteomic data pertaining to established rodent models of epilepsy and human epileptic patients showed overrepresentation of epilepsy associated genes in our PTZ regulated set. Conclusion Systems biology ultimately aims at delineating and comprehending the functioning of complex biological systems in such details that predictive models of human diseases could be developed. Due to immense complexity of higher organisms, systems biology approaches are however currently focused on simpler organisms. Amenable to modeling, our model offers a unique opportunity to further dissect epileptogenesis-like plasticity and to unravel mechanisms of long-term action of AEDs relevant in neuropsychiatric disorders.
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Pharmacodynamic and pharmacokinetic interaction profiles of levetiracetam in combination with gabapentin, tiagabine and vigabatrin in the mouse pentylenetetrazole-induced seizure model: an isobolographic analysis. Eur J Pharmacol 2009; 605:87-94. [PMID: 19168049 DOI: 10.1016/j.ejphar.2008.12.046] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Revised: 12/01/2008] [Accepted: 12/23/2008] [Indexed: 11/23/2022]
Abstract
To characterize the interactions between levetiracetam and the antiepileptic drugs gabapentin, tiagabine, and vigabatrin in suppressing pentylenetetrazole-induced clonic seizures in mice, type II isobolographic analysis was used. Clonic seizures were evoked in Albino Swiss mice by subcutaneous injection of pentylenetetrazole at its CD(97)(98 mg/kg). Adverse-effect profiles with respect to motor performance, long-term memory and skeletal muscular strength were measured along with total brain antiepileptic drug concentrations. The combination of gabapentin with levetiracetam at the fixed-ratios of 2:1, 1:1, 1:2, and 1:4 were supra-additive (synergistic) in terms of seizure suppression whilst the combination at the fixed-ratio of 4:1 was additive. Tiagabine with levetiracetam and vigabatrin with levetiracetam at the fixed-ratios of 1:25, 1:50, 1:100, 1:200, and 1:400 and at 2:1, 3:1, 4:1, 6:1, 8:1, and 16:1 were additive, respectively. No acute adverse effects were observed. Measurement of total brain antiepileptic drug concentrations revealed that levetiracetam in combination with gabapentin at the fixed-ratio of 1:4 significantly elevated (21%) total brain gabapentin concentrations. In contrast, levetiracetam was without affect on tiagabine or vigabatrin concentrations and co-administration with gabapentin, tiagabine or vigabatrin had no effect on levetiracetam brain concentrations, indicating the pharmacodynamic nature of interaction between these antiepileptic drugs in the mouse pentylenetetrazole model. The combination of gabapentin with levetiracetam at the fixed-ratios of 2:1, 1:1, 1:2, and 1:4 appears to be particularly favorable combination exerting supra-additive interaction in suppressing pentylenetetrazole-induced seizures, although there is a pharmacokinetic contribution to the interaction between levetiracetam and gabapentin at the fixed-ratio of 1:4. Levetiracetam in combination with tiagabine and vigabatrin appear to be neutral combinations producing only additivity in the mouse pentylenetetrazole model.
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Puzzling challenges in contemporary neuroscience: insights from complexity and emergence in epileptogenic circuits. Epilepsy Behav 2009; 14 Suppl 1:54-63. [PMID: 18835370 DOI: 10.1016/j.yebeh.2008.09.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Revised: 09/02/2008] [Accepted: 09/03/2008] [Indexed: 11/24/2022]
Abstract
The brain is a complex system that, in the normal condition, has emergent properties like those associated with activity-dependent plasticity in learning and memory, and in pathological situations, manifests abnormal long-term phenomena like the epilepsies. Data from our laboratory and from the literature were classified qualitatively as sources of complexity and emergent properties from behavior to electrophysiological, cellular, molecular, and computational levels. We used such models as brainstem-dependent acute audiogenic seizures and forebrain-dependent kindled audiogenic seizures. Additionally we used chemical or electrical experimental models of temporal lobe epilepsy that induce status epilepticus with behavioral, anatomical, and molecular sequelae such as spontaneous recurrent seizures and long-term plastic changes. Current computational neuroscience tools will help the interpretation, storage, and sharing of the exponential growth of information derived from those studies. These strategies are considered solutions to deal with the complexity of brain pathologies such as the epilepsies.
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Ulloa CM, Towfigh A, Safdieh J. Review of levetiracetam, with a focus on the extended release formulation, as adjuvant therapy in controlling partial-onset seizures. Neuropsychiatr Dis Treat 2009; 5:467-76. [PMID: 19777068 PMCID: PMC2747386 DOI: 10.2147/ndt.s4844] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Levetiracetam is a second-generation antiepileptic drug (AED) with a unique chemical structure and mechanism of action. The extended release formulation of levetiracetam (Keppra XR(); UCB Pharma) was recently approved by the Food and Drug Administration for adjunctive therapy in the treatment of partial-onset seizures in patients 16 years of age and older with epilepsy. This approval is based on a double-blind, randomized, placebo-controlled, multicenter, multinational trial. Levetiracetam XR allows for once-daily dosing, which may increase compliance and, given the relatively constant plasma concentrations, may minimize concentration-related adverse effects. Levetiracetam's mode of action is not fully elucidated, but it has been found to target high-voltage, N-type calcium channels as well as the synaptic vesicle protein 2A (SV2A). Levetiracetam has nearly ideal pharmacokinetics. It is rapidly and almost completely absorbed after oral ingestion, is <10% protein-bound, demonstrates linear kinetics, is minimally metabolized through a pathway independent of the cytochrome P450 system, has no significant drug-drug interactions, and has a wide therapeutic index. The most common reported adverse events with levetiracetam XR were somnolence, irritability, dizziness, nausea, influenza, and nasopharyngitis. Levetiracetam XR provides an efficacious and well-tolerated treatment option for adjunctive therapy in the treatment of partial-onset seizures.
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Affiliation(s)
- Carol M Ulloa
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY, USA
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