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MacKeigan D, Feja M, Meller S, Deking L, Javadova A, Veenhuis A, Felmy F, Gernert M. Long-lasting antiseizure effects of chronic intrasubthalamic convection-enhanced delivery of valproate. Neurobiol Dis 2023; 187:106321. [PMID: 37832796 DOI: 10.1016/j.nbd.2023.106321] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/25/2023] [Accepted: 10/10/2023] [Indexed: 10/15/2023] Open
Abstract
Intracerebral drug delivery is an experimental approach for the treatment of drug-resistant epilepsies that allows for pharmacological intervention in targeted brain regions. Previous studies have shown that targeted pharmacological inhibition of the subthalamic nucleus (STN) via modulators of the GABAergic system produces antiseizure effects. However, with chronic treatment, antiseizure effects are lost as tolerance develops. Here, we report that chronic intrasubthalamic microinfusion of valproate (VPA), an antiseizure medication known for its wide range of mechanisms of action, can produce long-lasting antiseizure effects over three weeks in rats. In the intravenous pentylenetetrazole seizure-threshold test, seizure thresholds were determined before and during chronic VPA application (480 μg/d, 720 μg/d, 960 μg/d) to the bilateral STN. Results indicate a dose-dependent variation in VPA-induced antiseizure effects with mean increases in seizure threshold of up to 33%, and individual increases of up to 150%. The lowest VPA dose showed a complete lack of tolerance development with long-lasting antiseizure effects. Behavioral testing with all doses revealed few, acceptable adverse effects. VPA concentrations were high in STN and low in plasma and liver. In vitro electrophysiology with bath applied VPA revealed a reduction in spontaneous firing rate, increased background membrane potential, decreased input resistance and a significant reduction in peak NMDA, but not AMPA, receptor currents in STN neurons. Our results suggest an advantage of VPA over purely GABAergic modulators in preventing tolerance development with chronic intrasubthalamic drug delivery and provide first mechanistic insights in intracerebral pharmacotherapy targeting the STN.
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Affiliation(s)
- Devlin MacKeigan
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany
| | - Malte Feja
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany.
| | - Sebastian Meller
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Lillian Deking
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Amina Javadova
- Center for Systems Neuroscience, 30559 Hannover, Germany; Institute for Zoology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Alva Veenhuis
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Felix Felmy
- Center for Systems Neuroscience, 30559 Hannover, Germany; Institute for Zoology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Manuela Gernert
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany.
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Meng XY, Li JJ, Ni TJ, Xiao-tong L, He T, Men ZN, Liu JS, Shen T. Electro-responsive brain-targeting mixed micelles based on Pluronic F127 and d-α-tocopherol polyethylene glycol succinate–ferrocene. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.124986] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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McCarren HS, Eisen MR, Nguyen DL, Dubée PB, Ardinger CE, Dunn EN, Haines KM, Santoro AN, Bodner PM, Ondeck CA, Honnold CL, McDonough JH, Beske PH, McNutt PM. Characterization and treatment of spontaneous recurrent seizures following nerve agent-induced status epilepticus in mice. Epilepsy Res 2020; 162:106320. [PMID: 32182542 PMCID: PMC7156324 DOI: 10.1016/j.eplepsyres.2020.106320] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 02/21/2020] [Accepted: 03/09/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE To develop and characterize a mouse model of spontaneous recurrent seizures following nerve agent-induced status epilepticus (SE) and test the efficacy of existing antiepileptic drugs. METHODS SE was induced in telemeterized male C57Bl6/J mice by soman exposure, and electroencephalographic activity was recorded for 4-6 weeks. Mice were treated with antiepileptic drugs (levetiracetam, valproic acid, phenobarbital) or corresponding vehicles for 14 d after exposure, followed by 14 d of drug washout. Survival, body weight, seizure characteristics, and histopathology were used to characterize the acute and chronic effects of nerve agent exposure and to evaluate the efficacy of treatments in mitigating or preventing neurological effects. RESULTS Spontaneous recurrent seizures manifested in all survivors, but the number and frequency of seizures varied considerably among mice. In untreated mice, seizures became longer over time. Moderate to severe histopathology was observed in the amygdala, piriform cortex, and CA1. Levetiracetam provided modest improvements in neurological parameters such as reduced spike rate and improved histopathology scores, whereas valproic acid and phenobarbital were largely ineffective. CONCLUSIONS This model of post-SE spontaneous recurrent seizures differs from other experimental models in the brief latency to seizure development, the occurrence of seizures in 100 % of exposed animals, and the lack of damage to CA4/dentate gyrus. It may serve as a useful tool for rapidly and efficiently screening novel therapies that would be effective against severe epilepsy cases.
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Affiliation(s)
- Hilary S McCarren
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States.
| | - Margaret R Eisen
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - Dominique L Nguyen
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - Parker B Dubée
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - Cherish E Ardinger
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - Emily N Dunn
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - Kari M Haines
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - Antonia N Santoro
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - Paige M Bodner
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - Celinia A Ondeck
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - Cary L Honnold
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - John H McDonough
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - Phillip H Beske
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
| | - Patrick M McNutt
- United States Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd Aberdeen Proving Ground, MD, 21010, United States
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Wang MJ, Jiang L, Chen HS, Cheng L. Levetiracetam Protects Against Cognitive Impairment of Subthreshold Convulsant Discharge Model Rats by Activating Protein Kinase C (PKC)-Growth-Associated Protein 43 (GAP-43)-Calmodulin-Dependent Protein Kinase (CaMK) Signal Transduction Pathway. Med Sci Monit 2019; 25:4627-4638. [PMID: 31266934 PMCID: PMC6601366 DOI: 10.12659/msm.913542] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Background Subclinical epileptiform discharges (SEDs) are defined as epileptiform electroencephalographic (EEG) discharges without clinical signs of seizure in patients. The subthreshold convulsant discharge (SCD) is a frequently used model for SEDs. This study aimed to investigate the effect of levetiracetam (LEV), an anti-convulsant drug, on cognitive impairment of SCD model rats and to assess the associated mechanisms. Material/Methods A SCD rat model was established. Rats were divided into an SCD group, an SCD+ sodium valproate (VPA) group, and an SCD+ levetiracetam (LEV) group. The Morris water maze was used to evaluate the capacity of positioning navigation and space exploration. The field excitatory post-synaptic potentials (fEPSPs) were evaluated using a bipolar stimulation electrode. NCAM, GAP43, PS95, and CaMK II levels were detected using Western blot and RT-PCR, respectively. PKC activity was examined by a non-radioactive method. Results LEV shortens the latency of platform seeking in SCD rats in positioning navigation. fEPSP slopes were significantly lower in the SCD group, and LEV treatment significantly enhanced the fEPSP slopes compared to the SCD group (P<0.05). The NCAM and GAP-43 levels were increased and PSD-95 levels were increased in SCD rats (P<0.05), which were improved by LEV treatment. The PKC activity and CaMK II levels were decreased in SCD rats and LEV treatment significantly enhanced PKC activity and increased CaMK II levels. Conclusions Cognitive impairment in of SCD model rats may be caused by decreased PKC activity, low expression of CaMK II, and inhibition of LTP formation. LEV can improve cognitive function by activating the PKC-GAP-43-CaMK signal transduction pathway.
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Affiliation(s)
- Min-Jian Wang
- Department of Psychology, Children's Hospital of Chongqing Medical University, Chongqing, China (mainland).,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China (mainland).,Key Laboratory of Pediatrics in Chongqing, Chongqing, China (mainland).,Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China (mainland)
| | - Li Jiang
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China (mainland).,Key Laboratory of Pediatrics in Chongqing, Chongqing, China (mainland).,Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China (mainland).,Department of Neurology, Children's Hospital of Chongqing Medical University, Chongqing, China (mainland)
| | - Heng-Sheng Chen
- Key Laboratory of Pediatrics in Chongqing, Chongqing, China (mainland).,Department of Neurology, Children's Hospital of Chongqing Medical University, Chongqing, China (mainland)
| | - Li Cheng
- Key Laboratory of Pediatrics in Chongqing, Chongqing, China (mainland).,Department of Neurology, Children's Hospital of Chongqing Medical University, Chongqing, China (mainland)
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Kunisawa K, Kido K, Nakashima N, Matsukura T, Nabeshima T, Hiramatsu M. Betaine attenuates memory impairment after water-immersion restraint stress and is regulated by the GABAergic neuronal system in the hippocampus. Eur J Pharmacol 2017; 796:122-130. [DOI: 10.1016/j.ejphar.2016.12.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 12/03/2016] [Accepted: 12/05/2016] [Indexed: 02/05/2023]
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Gorter JA, van Vliet EA, Lopes da Silva FH. Which insights have we gained from the kindling and post-status epilepticus models? J Neurosci Methods 2015; 260:96-108. [PMID: 25842270 DOI: 10.1016/j.jneumeth.2015.03.025] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 11/24/2022]
Abstract
Experimental animal epilepsy research got a big boost since the discovery that daily mild and short (seconds) tetanic stimulations in selected brain regions led to seizures with increasing duration and severity. This model that was developed by Goddard (1967) became known as the kindling model for epileptogenesis and has become a widely used model for temporal lobe epilepsy with complex partial seizures. During the late ninety-eighties the number of publications related to electrical kindling reached its maximum. However, since the kindling procedure is rather labor intensive and animals only develop spontaneous seizures (epilepsy) after hundreds of stimulations, research has shifted toward models in which the animals exhibit spontaneous seizures after a relatively short latent period. This led to post-status epilepticus (SE) models in which animals experience SE after injection of pharmacological compounds (e.g. kainate or pilocarpine) or via electrical stimulation of (limbic) brain regions. These post-SE models are the most widely used models in epilepsy research today. However, not all aspects of mesial temporal lobe epilepsy (MTLE) are reproduced and the widespread brain damage is often a caricature of the situation in the patient. Therefore, there is a need for models that can better replicate the disease. Kindling, although already a classic model, can still offer valid clues in this context. In this paper, we review different aspects of the kindling model with emphasis on experiments in the rat. Next, we review characteristic properties of the post-SE models and compare the neuropathological, electrophysiological and molecular differences between kindling and post-SE epilepsy models. Finally, we shortly discuss the advantages and disadvantages of these models.
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Affiliation(s)
- Jan A Gorter
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands.
| | - Erwin A van Vliet
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Fernando H Lopes da Silva
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands; Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal
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Profiles of multidrug resistance protein-1 in the peripheral blood mononuclear cells of patients with refractory epilepsy. PLoS One 2012; 7:e36985. [PMID: 22606322 PMCID: PMC3351424 DOI: 10.1371/journal.pone.0036985] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 04/11/2012] [Indexed: 01/16/2023] Open
Abstract
Background About one third of patients with epilepsy become refractory to therapy despite receiving adequate medical treatment, possibly from multidrug resistance. P-glycoprotein, encoded by multidrug resistance protein-1 (MDR1) gene, at the blood brain barrier is considered as a major factor mediating drug efflux and contributing to resistance. Given that peripheral blood mononuclear cells (PBMNCs) express MDR1, we investigated a MDR1 status of PBMNCs in various subsets of epilepsy patients and demonstrated their association with clinical characteristics. Methodology/Principal Findings Clinical and MDR1 data were collected from 140 patients with epilepsy, 30 healthy volunteers, and 20 control patients taking anti-epileptic drugs. PBMNCs were isolated, and basal MDR1 levels and MDR1 conformational change levels were measured by flow cytometry. MDR1 profiles were analyzed according to various clinical parameters, including seizure frequency and number of medications used in epilepsy patients. Epilepsy patients had a higher basal MDR1 level than non-epilepsy groups (p<0.01). Among epilepsy patients, there is a tendency for higher seizure frequency group to have higher basal MDR1 level (p = 0.059). The MDR1 conformational change level was significantly higher in the high-medication-use group than the low-use group (p = 0.028). Basal MDR1 (OR = 1.16 [95% CI: 1.060–1.268]) and conformational change level (OR = 1.11 [95% CI: 1.02–1.20]) were independent predictors for seizure frequency and number of medications, respectively. Conclusions/Significance The MDR1 profile of PBMNCs is associated with seizure frequency and medication conditions in patients with epilepsy.
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Large CH, Sokal DM, Nehlig A, Gunthorpe MJ, Sankar R, Crean CS, VanLandingham KE, White HS. The spectrum of anticonvulsant efficacy of retigabine (ezogabine) in animal models: Implications for clinical use. Epilepsia 2012; 53:425-36. [DOI: 10.1111/j.1528-1167.2011.03364.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Thakur A, Sahai AK, Thakur JS. Experimental re-evaluation of flunarizine as add-on antiepileptic therapy. J Pharm Bioallied Sci 2011; 3:253-8. [PMID: 21687355 PMCID: PMC3103921 DOI: 10.4103/0975-7406.80782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2010] [Revised: 11/10/2010] [Accepted: 11/24/2010] [Indexed: 11/04/2022] Open
Abstract
Background: Experimental studies have found several calcium channel blockers with anticonvulsant property. Flunarizine is one of the most potent calcium channel blockers, which has shown anticonvulsant effect against pentylenetetrazole (PTZ) and maximal electroshock (MES)-induced seizures. However, further experimental and clinical trials have shown varied results. We conducted a PTZ model experimental study to re-evaluate the potential of flunarizine for add-on therapy in the management of refractory epilepsy. Materials and Methods: Experiments were conducted in PTZ model involving Swiss strain mice. Doses producing seizures in 50% and 99% mice, i.e. CD50 and CD99 values of PTZ were obtained from the dose-response study. Animals received graded, single dose of sodium valproate (100–300 mg/kg), lamotrigine (3–12 mg/kg) and flunarizine (5–20 mg/kg), and then each group of mice was injected with CD99 dose of PTZ (65mg/kg i.p.). Another group of mice received single ED50 dose (dose producing seizure protection in 50% mice) of sodium valproate and flunarizine separately in left and right side of abdomen. Results were analysed by Kruskal–Wallis ANOVA on Ranks test. Results: As compared to control, sodium valproate at 250 mg/kg and 300 mg/kg produced statistical significant seizure protection. At none of the pre-treatment dose levels of lamotrigine, the seizure score with PTZ differed significantly from that observed in the vehicle-treated group. Pre-treatment with flunarizine demonstrated dose-dependent decrease in the seizure score to PTZ administration. As compared to control group, flunarizine at 20 mg/kg produced statistical significant seizure protection. Conclusion: As combined use of sodium valproate and flunarizine has shown significant seizure protection in PTZ model, flunarizine has a potential for add-on therapy in refractory cases of partial seizures. It is therefore, we conclude that further experimental studies and multicenter clinical trials involving large sample size are needed to establish flunarizine as add-on therapy in refractory epilepsy.
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Affiliation(s)
- Anamika Thakur
- Department of Pharmacology, IG Medical College, Shimla, Himachal Pradesh - 171 001, India
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