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Vukolova MN, Yen LY, Khmyz MI, Sobolevsky AI, Yelshanskaya MV. Parkinson's disease, epilepsy, and amyotrophic lateral sclerosis-emerging role of AMPA and kainate subtypes of ionotropic glutamate receptors. Front Cell Dev Biol 2023; 11:1252953. [PMID: 38033869 PMCID: PMC10683763 DOI: 10.3389/fcell.2023.1252953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 10/05/2023] [Indexed: 12/02/2023] Open
Abstract
Ionotropic glutamate receptors (iGluRs) mediate the majority of excitatory neurotransmission and are implicated in various neurological disorders. In this review, we discuss the role of the two fastest iGluRs subtypes, namely, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and kainate receptors, in the pathogenesis and treatment of Parkinson's disease, epilepsy, and amyotrophic lateral sclerosis. Although both AMPA and kainate receptors represent promising therapeutic targets for the treatment of these diseases, many of their antagonists show adverse side effects. Further studies of factors affecting the selective subunit expression and trafficking of AMPA and kainate receptors, and a reasonable approach to their regulation by the recently identified novel compounds remain promising directions for pharmacological research.
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Affiliation(s)
- Marina N. Vukolova
- Department of Pathophysiology, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Laura Y. Yen
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, United States
- Cellular and Molecular Physiology and Biophysics Graduate Program, Columbia University, New York, NY, United States
| | - Margarita I. Khmyz
- N. V. Sklifosovsky Institute of Clinical Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Alexander I. Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, United States
| | - Maria V. Yelshanskaya
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, United States
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Insight into Drug Resistance in Status Epilepticus: Evidence from Animal Models. Int J Mol Sci 2023; 24:ijms24032039. [PMID: 36768361 PMCID: PMC9917109 DOI: 10.3390/ijms24032039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/11/2023] [Accepted: 01/15/2023] [Indexed: 01/22/2023] Open
Abstract
Status epilepticus (SE), a condition with abnormally prolonged seizures, is a severe type of epilepsy. At present, SE is not well controlled by clinical treatments. Antiepileptic drugs (AEDs) are the main therapeutic approaches, but they are effective for SE only with a narrow intervening window, and they easily induce resistance. Thus, in this review, we provide an updated summary for an insight into drug-resistant SE, hoping to add to the understanding of the mechanism of refractory SE and the development of active compounds. Firstly, we briefly outline the limitations of current drug treatments for SE by summarizing the extensive experimental literature and clinical data through a search of the PubMed database, and then summarize the common animal models of refractory SE with their advantages and disadvantages. Notably, we also briefly review some of the hypotheses about drug resistance in SE that are well accepted in the field, and furthermore, put forward future perspectives for follow-up research on SE.
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Adotevi N, Lewczuk E, Sun H, Joshi S, Dabrowska N, Shan S, Williamson J, Kapur J. α-Amino-3-Hydroxy-5-Methyl-4-Isoxazolepropionic Acid Receptor Plasticity Sustains Severe, Fatal Status Epilepticus. Ann Neurol 2019; 87:84-96. [PMID: 31675128 DOI: 10.1002/ana.25635] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 10/30/2019] [Accepted: 10/30/2019] [Indexed: 01/06/2023]
Abstract
OBJECTIVE Generalized convulsive status epilepticus is associated with high mortality. We tested whether α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor plasticity plays a role in sustaining seizures, seizure generalization, and mortality observed during focal onset status epilepticus. We also determined whether modified AMPA receptors generated during status epilepticus could be targeted with a drug. METHODS Electrically induced status epilepticus was characterized by electroencephalogram and behavior in GluA1 knockout mice and in transgenic mice with selective knockdown of the GluA1 subunit in hippocampal principal neurons. Excitatory and inhibitory synaptic transmission in CA1 neurons was studied using patch clamp electrophysiology. The dose response of N,N,H,-trimethyl-5-([tricyclo(3.3.1.13,7)dec-1-ylmethyl]amino)-1-pentanaminiumbromide hydrobromide (IEM-1460), a calcium-permeable AMPA receptor antagonist, was determined. RESULTS Global removal of the GluA1 subunit did not affect seizure susceptibility; however, it reduced susceptibility to status epilepticus. GluA1 subunit knockout also reduced mortality, severity, and duration of status epilepticus. Absence of the GluA1 subunit prevented enhancement of glutamatergic synaptic transmission associated with status epilepticus; however, γ-aminobutyric acidergic synaptic inhibition was compromised. Selective removal of the GluA1 subunit from hippocampal principal neurons also reduced mortality, severity, and duration of status epilepticus. IEM-1460 rapidly terminated status epilepticus in a dose-dependent manner. INTERPRETATION AMPA receptor plasticity mediated by the GluA1 subunit plays a critical role in sustaining and amplifying seizure activity and contributes to mortality. Calcium-permeable AMPA receptors modified during status epilepticus can be inhibited to terminate status epilepticus. ANN NEUROL 2020;87:84-96.
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Affiliation(s)
- Nadia Adotevi
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Ewa Lewczuk
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Huayu Sun
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Suchitra Joshi
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Natalia Dabrowska
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Sarah Shan
- College of Arts and Sciences, University of Virginia, Charlottesville, VA
| | - John Williamson
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Jaideep Kapur
- Department of Neurology, University of Virginia, Charlottesville, VA.,Department of Neuroscience, University of Virginia, Charlottesville, VA.,UVA Brain Institute, University of Virginia, Charlottesville, VA
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Tchekalarova J, Atanasova D, Kortenska L, Lazarov N, Shishmanova-Doseva M, Galchev T, Marinov P. Agomelatine alleviates neuronal loss through BDNF signaling in the post-status epilepticus model induced by kainic acid in rat. Brain Res Bull 2019; 147:22-35. [PMID: 30738136 DOI: 10.1016/j.brainresbull.2019.01.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 01/12/2019] [Accepted: 01/16/2019] [Indexed: 12/11/2022]
Abstract
Recently, we have reported that while agomelatine (Ago) is unable to prevent development of epilepsy it exerts a strong neuroprotective and anti-inflammatory response in the KA post-status epilepticus (SE) rat model. In the present study, we aimed to explore whether the brain-derived neurotrophic factor (BDNF) in the hippocampus is involved in the neuroprotective effect of Ago against the KA-induced SE and epileptiform activity four months later in rats. Lacosamide (LCM) was used as a positive control. The EEG-recorded seizure activity was also evaluated in two treatment protocols. In Experiment#1, Ago given repeatedly at a dose of 40 mg/kg during the course of SE was unable neither to modify EEG-recorded epileptiform activity nor the video- and EEG-recorded spontaneous seizures four months later compared to LCM (50 mg/kg). However, both Ago and LCM inhibited the expression of BDNF in the mossy fibers and also prevented neuronal loss in the dorsal hippocampal and the piriform cortex after SE. In Experiment#2, acute injection of Ago and LCM on epileptic rats, characterized by high seizure rates, did not prevent EEG-recorded paroxysmal events while only LCM decreased either absolute or relative powers of gamma (28-60 Hz) and high (HI) (60-120 Hz) frequency bands to baseline in the frontal and parietal cortex, respectively. Our results suggest that the protection against neuronal loss in specific limbic regions and overexpressed BDNF in the mossy fibers resulting from the repeated treatment with Ago and LCM, respectively, during SE is not a prerequisite for alleviation of epileptogenesis and development of epilepsy. In addition, a reduction of gamma and HI bands in the frontal and parietal cortex is not associated with EEG-recorded paroxysmal events after acute injection of LCM.
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Affiliation(s)
- Jana Tchekalarova
- Institute of Neurobiology, Bulgarian Academy of Sciences (BAS), Sofia, Bulgaria.
| | - Dimitrinka Atanasova
- Institute of Neurobiology, Bulgarian Academy of Sciences (BAS), Sofia, Bulgaria; Department of Anatomy, Faculty of Medicine, Trakia University, Stara Zagora, Bulgaria
| | - Lidia Kortenska
- Institute of Neurobiology, Bulgarian Academy of Sciences (BAS), Sofia, Bulgaria
| | - Nikolai Lazarov
- Department of Anatomy and Histology, Medical University of Sofia, Sofia 1431, Bulgaria
| | | | | | - Pencho Marinov
- Institute of Information and Communication Technologies, BAS, Sofia, Bulgaria
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Perampanel chronic treatment does not induce tolerance and decreases tolerance to clobazam in genetically epilepsy prone rats. Epilepsy Res 2018; 146:94-102. [DOI: 10.1016/j.eplepsyres.2018.07.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 02/08/2018] [Accepted: 07/24/2018] [Indexed: 11/24/2022]
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Leo A, Giovannini G, Russo E, Meletti S. The role of AMPA receptors and their antagonists in status epilepticus. Epilepsia 2018; 59:1098-1108. [DOI: 10.1111/epi.14082] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2018] [Indexed: 01/08/2023]
Affiliation(s)
- Antonio Leo
- Department of Science of Health; University Magna Graecia of Catanzaro; Catanzaro Italy
| | - Giada Giovannini
- Department of Biomedical Metabolic and Neural Sciences; University of Modena and Reggio Emilia; Modena Italy
| | - Emilio Russo
- Department of Science of Health; University Magna Graecia of Catanzaro; Catanzaro Italy
| | - Stefano Meletti
- Department of Biomedical Metabolic and Neural Sciences; University of Modena and Reggio Emilia; Modena Italy
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Di Bonaventura C, Labate A, Maschio M, Meletti S, Russo E. AMPA receptors and perampanel behind selected epilepsies: current evidence and future perspectives. Expert Opin Pharmacother 2017; 18:1751-1764. [PMID: 29023170 DOI: 10.1080/14656566.2017.1392509] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION The alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors are the major mediators of glutamate-mediated excitatory neurotransmission, and are critical for synchronization and spread of epileptic activity. Areas covered: AMPA receptor antagonists have been also developed as antiepileptic drugs and perampanel (PER) is the first highly selective, non-competitive AMPA-type glutamate receptor antagonist that is available on the market. It is approved as adjunctive therapy for the treatment of partial-onset seizures with or without secondary generalization, and for primary generalized tonic-clonic seizures in idiopathic generalized epilepsy, in patients aged ≥ 12 years. This article reviews the role of AMPA receptors in the neuronal hyperexcitability underlying epilepsy, the mechanism of action and clinical experience on the anti-seizure activity of PER. Moreover, the rationale for targeting AMPA receptor in specific epileptic disorders, including brain tumor-related epilepsy, mesial temporal lobe epilepsy with/without hippocampal sclerosis, and status epilepticus is evaluated. Finally, the pharmacological rationale for the development of AMPA receptor antagonists in other neurological disorders beyond epilepsy is considered. Expert opinion: Further research aimed at better understanding the pharmacology and blocking mechanism of PER and other AMPA receptor antagonists will drive future development of therapeutic agents that target epilepsy and other neurological diseases.
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Affiliation(s)
- Carlo Di Bonaventura
- a Department of Neurology and Psychiatry, Neurology Unit , 'Sapienza' University , Rome , Italy
| | - Angelo Labate
- b Institute of Neurology , University Magna Graecia of Catanzaro , Catanzaro , Italy.,c Institute of Molecular Bioimaging and Physiology of the National Research Council , Catanzaro , Italy
| | - Marta Maschio
- d Center for Tumor-related Epilepsy, UOSD Neurology , Regina Elena National Cancer Institute , Rome , Italy
| | - Stefano Meletti
- e Department of Biomedical, Metabolic and Neural Sciences, Center for Neuroscience and Neurotechnology , University of Modena and Reggio Emilia , Modena , Italy
| | - Emilio Russo
- f Department of Science of Health, School of Medicine and Surgery , University 'Magna Graecia' of Catanzaro , Catanzaro , Italy
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Joshi S, Rajasekaran K, Sun H, Williamson J, Kapur J. Enhanced AMPA receptor-mediated neurotransmission on CA1 pyramidal neurons during status epilepticus. Neurobiol Dis 2017; 103:45-53. [PMID: 28377128 PMCID: PMC5481781 DOI: 10.1016/j.nbd.2017.03.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 03/29/2017] [Accepted: 03/31/2017] [Indexed: 12/20/2022] Open
Abstract
Status epilepticus (SE) is a common neurological emergency that results from the failure of the mechanisms responsible for seizure termination or the initiation of mechanisms that lead to abnormally prolonged seizures. Although the failure of inhibitory mechanisms during SE is well understood, the seizure-initiating mechanisms are poorly understood. We tested whether hippocampal α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated transmission was enhanced during SE and assessed the underlying molecular mechanism. In animals in self-sustaining limbic SE the amplitudes of the miniature, spontaneous, and AMPA-evoked excitatory currents recorded from the CA1 pyramidal neurons were larger than those recorded in the controls. The evoked EPSCs rectified inwardly. In these animals, the surface expression of GluA1 subunit-containing AMPARs was increased in the CA1 pyramidal neurons. The phosphorylation of the GluA1 subunit on S831 and S845 residues was reduced in animals in SE. In contrast, the GluA1 subunit surface expression and AMPAR-mediated neurotransmission of dentate granule cells (DGCs) was not altered. Treating animals in SE with the NMDAR antagonist MK-801 or with diazaepam blocked the increased surface expression of the GluA1 subunits. NMDAR blockade also prevented the dephosphorylation of the S845 residue but not that of S831. Targeting NMDARs and AMPARs may provide novel strategies to treat benzodiazepine-refractory SE.
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Affiliation(s)
- Suchitra Joshi
- Department of Neurology, University of Virginia, Charlottesville, VA 22908, United States
| | - Karthik Rajasekaran
- Department of Neurology, University of Virginia, Charlottesville, VA 22908, United States
| | - Huayu Sun
- Department of Neurology, University of Virginia, Charlottesville, VA 22908, United States
| | - John Williamson
- Department of Neurology, University of Virginia, Charlottesville, VA 22908, United States
| | - Jaideep Kapur
- Department of Neurology, University of Virginia, Charlottesville, VA 22908, United States; Department of Neuroscience University of Virginia, Charlottesville, VA 22908, United States.
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Wu T, Ido K, Osada Y, Kotani S, Tamaoka A, Hanada T. The neuroprotective effect of perampanel in lithium-pilocarpine rat seizure model. Epilepsy Res 2017. [PMID: 28624183 DOI: 10.1016/j.eplepsyres.2017.06.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE Status epilepticus (SE) causes irreversible neurodegeneration if not terminated quickly. Perampanel (PER), a potent AMPA receptor antagonist, has previously been shown to terminate seizures in the lithium-pilocarpine SE model. In the present study, we assessed whether PER would also prevent neuronal damage in this model. METHODS SE was induced in rats using lithium chloride and pilocarpine. Initiation of SE was defined as continuous seizures that exhibited as rearing accompanied by bilateral forelimb clonus (Racine score 4). Either PER (0.6, 2, or 6mg/kg) or diazepam (DZP, 10mg/kg) was administered intravenously 30min after SE initiation. Histopathological samples from treated and seizure-naive rats were taken one week after treatment and then stained with an anti-neuronal nuclei (NeuN) antibody. The sections were analyzed by using a pixel-counting algorithm to quantify the amount of staining in the CA1 subregion of the hippocampus, piriform cortex (Pir), and mediodorsal thalamic nucleus (MD). RESULTS DZP administration did not suppress seizures or the degeneration of neurons in the examined areas. Seizures were terminated in 100% of rats treated with 6mg/kg PER (n=8) and in 47% (7/15) of rats treated with 2mg/kg PER, and neurons in the analyzed areas of these animals were preserved to the level seen in naive rats. In the eight animals in which 2mg/kg PER did not terminate the seizures, neuronal loss was partially attenuated in CA1 and Pir, and neurons were fully preserved in MD. Treatment with 0.6mg/kg PER did not terminate the seizures or significantly preserve neurons. The anti-seizure effect of PER correlated well with the degree of neuroprotection in each analyzed area. CONCLUSIONS PER exhibited a strong neuroprotective effect in a drug-refractory SE model, and this effect was correlated with its attenuation of seizure.
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Affiliation(s)
- Ting Wu
- Neurology, Tsukuba Research Department, Discovery, Medicine Creation, Neurology Business Group, Eisai Co., Ltd., Japan; Clinical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Japan.
| | - Katsutoshi Ido
- Neurology, Tsukuba Research Department, Discovery, Medicine Creation, Neurology Business Group, Eisai Co., Ltd., Japan
| | - Yoshihide Osada
- Neurology, Tsukuba Research Department, Discovery, Medicine Creation, Neurology Business Group, Eisai Co., Ltd., Japan
| | - Sadaharu Kotani
- Neurology, Tsukuba Research Department, Discovery, Medicine Creation, Neurology Business Group, Eisai Co., Ltd., Japan
| | - Akira Tamaoka
- Institute of Clinical Medicine, Department of Neurology, University of Tsukuba, Japan
| | - Takahisa Hanada
- Neurology, Tsukuba Research Department, Discovery, Medicine Creation, Neurology Business Group, Eisai Co., Ltd., Japan
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Keppel Hesselink JM. NS1209/SPD 502, A Novel Selective AMPA Antagonist for Stroke, Neuropathic Pain or Epilepsy? Drug Development Lessons Learned. Drug Dev Res 2017; 78:75-80. [PMID: 28195646 DOI: 10.1002/ddr.21376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Preclinical Research The selective AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptor antagonist, NS1209 (also known as SPD 502) has been explored in several research and development campaigns since its selection as a lead drug candidate in the early 1990s by the Danish biotechnology company, NeuroSearch. The compound was successively tested in animal models of stroke, neuropathic pain and epilepsy. The preclinical data to support development for the treatment of stroke were incomplete, as the compound was administered after the stroke episode, and did not protect subcortical areas of the brain. Preclinical data for neuropathic pain and epilepsy appeared more promising, but the design of the Phase IIa studies in both indications was suboptimal, and an exploratory study in neuropathic pain, like one in refractory epilepsy gave inconclusive results. Preclinical data in pain models were much less convincing than reported by the authors in abstract and discussion sections. Due to a long preclinical sequential testing phase and insufficiently powered clinical trials, NS 1209 disappeared from the CNS development pipeline, while its patent protection exclusivity was markedly reduced due to the unfortunate slow speed in development-a phenomenon far from unusual in CNS drug discovery. NeuroSearch ceased operations as an R&D entity in 2012 and its R & D portfolio was transferred to Teva Pharmaceuticals and to a spin off, Saniona A/S. Based on an in-depth case analysis of the development of NS 1209, a number of recommendations are given to reduce chances of failure during clinical development of neuropathic pain compounds and, more generally, of CNS compounds. Drug Dev Res 78 : 75-80, 2017. © 2017 Wiley Periodicals, Inc.
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Perampanel in patients with refractory and super-refractory status epilepticus in a neurological intensive care unit. Epilepsy Behav 2015; 49:354-8. [PMID: 25962657 DOI: 10.1016/j.yebeh.2015.04.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 04/03/2015] [Indexed: 12/19/2022]
Abstract
INTRODUCTION In refractory status epilepticus (SE), because of subcellular maladaptive changes, GABAergic drugs are no longer effective, and the excitatory neurotransmitter glutamate (Glu) plays a major role in seizure perpetuation. Perampanel (PER, licensed since 09/2012) is the first orally active noncompetitive AMPA receptor antagonist for adjunctive treatment of refractory focal epilepsy. METHODS We analyzed treatment response, seizure outcome, and adverse effects of add-on treatment with perampanel in patients with refractory status epilepticus in the Neurological Intensive Care Unit (NICU), Salzburg, Austria between 09/2012 and 11/2014 by retrospective chart review. RESULTS Twelve patients (75% women) with refractory status epilepticus were treated with PER administered per nasogastric tube between 09/2012 and 11/2014. Median age was 75 years [range: 60-91]. The most frequent SE type was nonconvulsive SE (NCSE) with (5/12, 42%) and without coma (6/12, 50%). In seven patients (58%), SE arose de novo, with an acute symptomatic cause in five patients (42%). Cerebrovascular diseases (4/12, 33%) and cerebral tumors (4/12, 33%) were the most common etiologies. Perampanel was given after a median number of four antiepileptic drugs [range: 2-7] and a median time of 1.5 days [range: 0.8-18.3]. In one patient (8%), clinical improvement was observed within 24h and EEG improvement within 60 h after administration of PER, while in another patient (8%), clinical and EEG improvement was observed more than 48 h after administration. Median initial dose was 4 mg [range: 2-12; SD: 4.11], titrated up to a median of 12 mg [range: 4-12] in steps of 2 to 4 mg per day. No adverse effects were reported regarding cardiorespiratory changes or laboratory parameters. Outcomes after SE were moderate disability in five patients (42%), death in three patients (25%), and persistent vegetative state in two patients (17%). CONCLUSION Though glutamate plays a major role in seizure perpetuation, the noncompetitive AMPA receptor antagonist PER could only ameliorate seizure activity in a few patients with refractory SE. The long duration of SE before the administration of PER via nasogastric tube, as well as relatively low doses of PER, might be responsible for the modest result. Perampanel was well tolerated, and no adverse events were reported. This article is part of a Special Issue entitled Status Epilepticus.
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Twele F, Bankstahl M, Klein S, Römermann K, Löscher W. The AMPA receptor antagonist NBQX exerts anti-seizure but not antiepileptogenic effects in the intrahippocampal kainate mouse model of mesial temporal lobe epilepsy. Neuropharmacology 2015; 95:234-42. [PMID: 25839899 DOI: 10.1016/j.neuropharm.2015.03.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 02/26/2015] [Accepted: 03/19/2015] [Indexed: 01/05/2023]
Abstract
The AMPA receptor subtype of glutamate receptors, which mediates fast synaptic excitation, is of primary importance in initiating epileptiform discharges, so that AMPA receptor antagonists exert anti-seizure activity in diverse animal models of partial and generalized seizures. Recently, the first AMPA receptor antagonist, perampanel, was approved for use as adjunctive therapy for the treatment of resistant partial seizures in patients. Interestingly, the competitive AMPA receptor antagonist NBQX has recently been reported to prevent development of spontaneous recurrent seizures (SRS) in a neonatal seizure model in rats, indicating the AMPA antagonists may exert also antiepileptogenic effects. This prompted us to evaluate competitive (NBQX) and noncompetitive (perampanel) AMPA receptor antagonists in an adult mouse model of mesial temporal lobe epilepsy. In this model, SRS develop after status epilepticus (SE) induced by intrahippocampal injection of kainate. Focal electrographic seizures in this model are resistant to several major antiepileptic drugs. In line with previous studies, phenytoin was not capable of blocking such seizures in the present experiments, while they were markedly suppressed by NBQX and perampanel. However, perampanel was less tolerable than NBQX in epileptic mice, so that only NBQX was subsequently tested for antiepileptogenic potential. When mice were treated over three days after kainate-induced SE with NBQX (20 mg/kg t.i.d.), no effect on development or frequency of seizures was found in comparison to vehicle controls. These results suggest that AMPA receptor antagonists, while being effective in suppressing resistant focal seizures, are not exerting antiepileptogenic effects in an adult mouse model of partial epilepsy.
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Affiliation(s)
- Friederike Twele
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany
| | - Marion Bankstahl
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany
| | - Sabine Klein
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany
| | - Kerstin Römermann
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany
| | - Wolfgang Löscher
- 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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Hanada T, Ido K, Kosasa T. Effect of perampanel, a novel AMPA antagonist, on benzodiazepine-resistant status epilepticus in a lithium-pilocarpine rat model. Pharmacol Res Perspect 2014; 2:e00063. [PMID: 25505607 PMCID: PMC4186423 DOI: 10.1002/prp2.63] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 06/17/2014] [Accepted: 06/24/2014] [Indexed: 12/15/2022] Open
Abstract
This study assessed the efficacy of diazepam, and the alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor antagonists perampanel and GYKI52466 in a lithium-pilocarpine status epilepticus (SE) model. SE was induced in rats using lithium chloride, scopolamine methyl bromide, and pilocarpine. Diazepam 10, 20, or 40 mg kg−1, or perampanel 1, 2.5, 5, or 8 mg kg−1 were administered intravenously at 10 or 30 min after seizure onset, and GYKI52466 50 mg kg−1, or combinations of diazepam 2.5–5 mg kg−1 and perampanel 0.5–1 mg kg−1, were administered intravenously at 30 min after seizure onset. Diazepam 20 mg kg−1 terminated seizures (based on electroencephalography and assessment of behavioral seizures) in 2/6 rats at 10 min and 0/6 rats at 30 min (ED50: 10 min, 30 mg kg−1; 30 min, not determined). Perampanel 8 mg kg−1 terminated seizures in 6/6 rats at both 10 and 30 min (ED50: 10 min 1.7 mg kg−1; 30 min, 5.1 mg kg−1). GYKI52466 50 mg kg−1 terminated seizures in 2/4 rats at 30 min. Co-administration of diazepam 5 mg kg−1 and perampanel 1 mg kg−1 terminated seizures in 9/9 rats at 30 min. In conclusion, perampanel and GYKI52466 provided efficacy in a lithium-pilocarpine SE model at 30 min after seizure onset, when SE was refractory to diazepam, supporting the therapeutic potential of AMPA receptor antagonists for refractory SE. The perampanel dose required to terminate seizures was reduced by combination with diazepam, suggesting synergy.
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Affiliation(s)
- Takahisa Hanada
- Global Biopharmacology, Neuroscience & General Medicine Product Creation System, Eisai Co., Ltd Tsukuba, Ibaraki, Japan ; Center for Tsukuba Advanced Research Alliance, Graduate School of Life and Environmental Sciences, University of Tsukuba Tsukuba, Ibaraki, Japan
| | - Katsutoshi Ido
- Global Biopharmacology, Neuroscience & General Medicine Product Creation System, Eisai Co., Ltd Tsukuba, Ibaraki, Japan
| | - Takashi Kosasa
- Global Biopharmacology, Neuroscience & General Medicine Product Creation System, Eisai Co., Ltd Tsukuba, Ibaraki, Japan
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Citraro R, Aiello R, Franco V, De Sarro G, Russo E. Targeting α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors in epilepsy. Expert Opin Ther Targets 2014; 18:319-34. [PMID: 24387310 DOI: 10.1517/14728222.2014.874416] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
INTRODUCTION Despite epilepsies being between the oldest and most studied neurological diseases, new treatment remains an unmet need of scientific research due to the high percentage of refractory patients. Several studies have identified new suitable anti-seizure targets. Glutamate activation of α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors (AMPARs) have long ago been identified as suitable targets for the development of anti seizure drugs. AREAS COVERED Here, we describe: i) AMPARs' structure and their involvement and role during seizures and in epilepsy and ii) the efficacy of AMPAR antagonists in preclinical models of seizures and epilepsy. EXPERT OPINION The physiological and pathological role of AMPAR in the CNS and the development of AMPAR antagonists have recently gained attention considering their recent involvement in status epilepticus and the marketing of perampanel. The need for new anti-seizure drugs represents a major challenge in both preclinical and clinical epilepsy. The introduction into the market of perampanel for the treatment of epilepsy will shed new light on the real potential of AMPAR antagonism in clinical settings outside the limited world of clinical trials. While research will go on in this area, fundamental will be the post-marketing evaluation of perampanel efficacy and tolerability and a better definition of the role of this receptor in the epileptic brain.
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Affiliation(s)
- Rita Citraro
- University "Magna Graecia" of Catanzaro, School of Medicine, Science of Health Department , Catanzaro , Italy
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15
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An in vivo technique for investigating electrophysiological effects of centrally administered drugs on single neurons and network behaviour. J Neurosci Methods 2013; 219:197-204. [PMID: 23872526 DOI: 10.1016/j.jneumeth.2013.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 06/22/2013] [Accepted: 06/28/2013] [Indexed: 11/21/2022]
Abstract
Single neuronal juxtacellular recording with simultaneous cortical electroencephalogram (EEG) in whole-animal preparations in vivo has allowed the study of the behaviour of individual neurons in relation to whole brain activity. Data on single neuron firing, neural synchrony, network behaviour and their responses to pharmacological agents can be obtained with dual recordings. However, pharmacological effects on cellular and network activity during paired single-unit recordings have not been possible due to the difficulties in maintaining recordings of two cells for a prolonged period. Here, we describe a method of maintaining stable dual cell juxtacellular recordings from distinct brain regions, allowing the assessment of single unit activity before, during and after the intracerebroventricular (ICV) injection of drugs. Data collection using this technique allows correlation both between the two cells and with whole-brain EEG, and their responses to pharmacological interventions. This is particularly useful for the investigation of the effects of anti-epileptic drugs on animal models of epilepsy, where single unit activity of two cells from distinct regions can be correlated with each other and with whole-brain activity during pre-ictal, ictal and interictal states. We also describe standardised analytical methods of quantifying cell firing patterns, the rhythmicity of individual neurons and the synchronicity of firing between two neurons in ictal and interictal periods and their responses to drug exposure.
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16
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Rogawski MA. AMPA receptors as a molecular target in epilepsy therapy. Acta Neurol Scand 2013:9-18. [PMID: 23480151 DOI: 10.1111/ane.12099] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2013] [Indexed: 11/28/2022]
Abstract
Epileptic seizures occur as a result of episodic abnormal synchronous discharges in cerebral neuronal networks. Although a variety of non-conventional mechanisms may play a role in epileptic synchronization, cascading excitation within networks of synaptically connected excitatory glutamatergic neurons is a classical mechanism. As is the case throughout the central nervous system, fast synaptic excitation within and between brain regions relevant to epilepsy is mediated predominantly by AMPA receptors. By inhibiting glutamate-mediated excitation, AMPA receptor antagonists markedly reduce or abolish epileptiform activity in in vitro preparations and confer seizure protection in a broad range of animal seizure models. NMDA receptors may also contribute to epileptiform activity, but NMDA receptor blockade is not sufficient to eliminate epileptiform discharges. AMPA receptors move into and out of the synapse in a dynamic fashion in forms of synaptic plasticity, underlying learning and memory. Often, the trigger for these dynamic movements is the activation of NMDA receptors. While NMDA receptor antagonists inhibit these forms of synaptic plasticity, AMPA receptor antagonists do not impair synaptic plasticity and do not inhibit memory formation or retrieval. The demonstrated clinical efficacy of perampanel, a high-potency, orally active non-competitive AMPA receptor antagonist, supports the concept that AMPA receptors are critical to epileptic synchronization and the generation and spread of epileptic discharges in human epilepsy.
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Affiliation(s)
- M. A. Rogawski
- Department of Neurology; School of Medicine and Center for Neuroscience; University of California, Davis; Sacramento; CA; USA
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Sabers A, Wolf P, Møller A, Rysgaard K, Ben-Menachem E. A prospective, randomized, multicentre trial for the treatment of refractory status epilepticus; experiences from evaluating the effect of the novel drug candidate, NS1209. Epilepsy Res 2013; 106:292-5. [DOI: 10.1016/j.eplepsyres.2013.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 03/28/2013] [Accepted: 04/01/2013] [Indexed: 11/15/2022]
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Dorandeu F, Dhote F, Barbier L, Baccus B, Testylier G. Treatment of status epilepticus with ketamine, are we there yet? CNS Neurosci Ther 2013; 19:411-27. [PMID: 23601960 PMCID: PMC6493567 DOI: 10.1111/cns.12096] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 02/23/2013] [Accepted: 02/23/2013] [Indexed: 12/24/2022] Open
Abstract
Status epilepticus (SE), a neurological emergency both in adults and in children, could lead to brain damage and even death if untreated. Generalized convulsive SE (GCSE) is the most common and severe form, an example of which is that induced by organophosphorus nerve agents. First- and second-line pharmacotherapies are relatively consensual, but if seizures are still not controlled, there is currently no definitive data to guide the optimal choice of therapy. The medical community seems largely reluctant to use ketamine, a noncompetitive antagonist of the N-methyl-d-aspartate glutamate receptor. However, a review of the literature clearly shows that ketamine possesses, in preclinical studies, antiepileptic properties and provides neuroprotection. Clinical evidences are scarcer and more difficult to analyze, owing to a use in situations of polytherapy. In absence of existing or planned randomized clinical trials, the medical community should make up its mind from well-conducted preclinical studies performed on appropriate models. Although potentially active, ketamine has no real place for the treatment of isolated seizures, better accepted drugs being used. Its best usage should be during GCSE, but not waiting for SE to become totally refractory. Concerns about possible developmental neurotoxicity might limit its pediatric use for refractory SE.
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Affiliation(s)
- Frederic Dorandeu
- Département de Toxicologie et risques chimiques, Institut de Recherche Biomédicale des Armées - Centre de Recherches du Service de Santé des Armées (IRBA-CRSSA), La Tronche Cedex, France.
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Abstract
INTRODUCTION Epilepsy is one of the most common serious neurological disorders in adults, affecting approximately 50 million people worldwide at a total annual cost, in Europe, of approximately 15.5 billion Euros. AREAS COVERED The present paper reviews current compounds in preclinical and clinical development for the treatment of focal epilepsies, namely, ganaxolone, perampanel, BGG-492, NS-1209, belnacasan, YKP-3089, brivaracetam. New formulations in clinical development, such as intranasal midazolam, diazepam auto-injection, a new formulation of valproic acid using drug targeting technology and controlled release formulations for topiramate and pregabalin, are also discussed. EXPERT OPINION During the last 30 years, antiepileptic drugs (AEDs) development have been based on specific assumptions regarding the neurobiology of epilepsy but all marketed drugs have not changed the proportion of drug refractory patients. AEDs in development with new mechanisms of actions, especially anti-inflammatory agents, are of interest. AMPA blockers, especially water-soluble ones, being suitable for parenteral formulation, can be of relevance in treating refractory status epilepticus, a major life-threatening complication. Finally, new formulations, especially those adopting drug targeting technologies are promising in order to maximize the efficacy with very limited adverse effects.
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Affiliation(s)
- Marco Mula
- Amedeo Avogadro University, University Hospital Maggiore della Carità, Division of Neurology, C.so Mazzini 18, 28100 Novara, Italy.
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20
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Rajasekaran K, Todorovic M, Kapur J. Calcium-permeable AMPA receptors are expressed in a rodent model of status epilepticus. Ann Neurol 2012; 72:91-102. [PMID: 22829271 DOI: 10.1002/ana.23570] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE A study was undertaken to characterize the plasticity of AMPA receptor (AMPAR)-mediated neurotransmission in the hippocampus during status epilepticus (SE). METHODS SE was induced by pilocarpine, and animals were studied 10 minutes (refractory SE) or 60 minutes (late SE) after the onset of the first grade 5 seizures. AMPAR-mediated currents were recorded from CA1 pyramidal neurons and dentate granule cells (DGCs) by voltage clamp technique. The surface expression of GluA2 subunit on hippocampal membranes was determined using a biotinylation assay. GluA2 internalization and changes in intracellular calcium ([Ca](i)) levels were studied in hippocampal cultures using immunocytochemical and live-imaging techniques. AMPAR antagonist treatment of SE was evaluated by video and electroencephalography. RESULTS AMPAR-mediated currents recorded from CA1 neurons from refractory and late SE animals were inwardly rectifying, and philanthotoxin-sensitive; similar changes were observed in recordings obtained from DGCs from refractory SE animals. GluA2 subunit surface expression was reduced in the hippocampus during refractory and late SE. In cultured hippocampal pyramidal neurons, recurrent bursting diminished surface expression of the GluA2 subunit and enhanced its internalization rate. Recurrent bursting-induced increase in [Ca](i) levels was reduced by selective inhibition of GluA2-lacking AMPARs. GYKI-52466 terminated diazepam-refractory SE. INTERPRETATION During SE, there is rapid, ongoing plasticity of AMPARs with the expression of GluA2-lacking AMPARs. These receptors provide another source of Ca(2+) entry into the principal neurons. Benzodiazepam-refractory SE can be terminated by AMPAR antagonism. The data identify AMPARs as a potential therapeutic target for the treatment of SE.
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Abstract
Despite of established and effective therapy for epilepsy, 20–25% patients develop therapeutic failure; this encourages finding newer drugs. Novel approaches target receptors which remain unaffected by conventional therapy or inhibit epileptogenesis. AMPA receptor antagonists have shown faster and complete protection compared to diazepam. Protein kinase (PK) plays an important role in the development of epilepsy. PK inhibitors such as K252a, VID-82925, and Herbimycin A have been found effective in inhibition of spread of epileptiform activity and epileptogenesis. Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors classified into three groups. Group 1 mGluRs antagonist and Groups 2 and 3 mGluRs agonists inhibited pentylenetetrazole-induced kindled seizures. Combined use of these agents has also shown favorable results. Mammalian target of rapamycin (mTOR) plays a central role in multiple mechanisms of epileptogenesis. mTOR causes transcription, induction of proapoptotic proteins, and autophagy inhibition. Rapamycin was effective in suppression of recurrent seizures as well as in tuberous sclerosis and acute brain injury model. 5% CO2 showed potent effects on cortical epileptiform activity and convulsions in animal epilepsy models and in humans with drug-resistant partial epilepsy. It is found to be rapidly acting, safe and cheap, thus it can be a good option in emergency for suppression of seizure. Neurosteroids are considered as fourth generation neuromessengers, they act as positive allosteric modulators of γ-aminobutyric acid (GABAA) receptors. Clinical trial of ganaxolone, an allopregnanolone analogue, has shown a beneficial role in pharmacoresistant epilepsy. However, most of these drugs are tested in early phases of development and the possible use and safety in epilepsy has to be proven in clinical trials.
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Affiliation(s)
- Ashish P Anovadiya
- Department of Pharmacology, Government Medical College, Bhavnagar, Gujarat, India
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22
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Lemoine D, Jiang R, Taly A, Chataigneau T, Specht A, Grutter T. Ligand-gated ion channels: new insights into neurological disorders and ligand recognition. Chem Rev 2012; 112:6285-318. [PMID: 22988962 DOI: 10.1021/cr3000829] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Damien Lemoine
- Laboratoire de Biophysicochimie des Récepteurs Canaux, UMR 7199 CNRS, Conception et Application de Molécules Bioactives, Faculté de Pharmacie, Université de Strasbourg , 67400 Illkirch, France
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Russo E, Gitto R, Citraro R, Chimirri A, De Sarro G. New AMPA antagonists in epilepsy. Expert Opin Investig Drugs 2012; 21:1371-89. [DOI: 10.1517/13543784.2012.705277] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Emilio Russo
- University “Magna Graecia” of Catanzaro, School of Medicine, Science of Health Department,
Catanzaro, Italy
| | - Rosaria Gitto
- University of Messina, Farmaco-Chimico Department,
Messina, Italy
| | - Rita Citraro
- University “Magna Graecia” of Catanzaro, School of Medicine, Science of Health Department,
Catanzaro, Italy
| | - Alba Chimirri
- University of Messina, Farmaco-Chimico Department,
Messina, Italy
| | - Giovambattista De Sarro
- University “Magna Graecia” of Catanzaro, School of Medicine, Science of Health Department,
Catanzaro, Italy
- University of Catanzaro, School of Medicine, Department of Experimental and Clinical Medicine,
Via T. Campanella, 115, 88100 Catanzaro, Italy ;
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24
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Mood disorders. Transl Neurosci 2012. [DOI: 10.1017/cbo9780511980053.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Inter-individual variation in the anticonvulsant effect of phenobarbital in the pilocarpine rat model of temporal lobe epilepsy. Exp Neurol 2012; 234:70-84. [DOI: 10.1016/j.expneurol.2011.12.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 12/02/2011] [Accepted: 12/09/2011] [Indexed: 11/18/2022]
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Abstract
Although most people presenting with partial-onset seizures will achieve control with antiepileptic medication, a considerable minority will have difficult-to-treat epilepsy that is resistant to existing medication. Over the last few years, a large number of new antiepileptic drugs have been developed. Some of these have a novel mode of action. Many of the older antiepileptic drugs act through sodium channels or by enhancement of gamma amino butyric acid (GABA). Lamotrigine has sodium-channel blocking properties but also has other important modes of action, indicated by efficacy in treating not only partial-onset but also generalized seizures. Vigabatrin and tiagabine both increase GABA activity, by inhibiting GABA transaminase and limiting GABA reuptake, respectively. The main mode of action of gabapentin and pregabalin is not via GABA but through a selective inhibitory effect on voltage-gated calcium channels containing the α(2)δ-1 subunit. Levetiracetam inhibits the recycling of SV2A (synaptic vesicle protein 2A) neurotransmitter vesicles but also has other effects, including inhibition of voltage-dependent calcium channels. Some drugs, eg, felbamate, zonisamide, and topiramate, have multiple modes of action. In many cases, although the main mode of action may have been identified, other modes of action also play a role. Two recently developed antiepileptic drugs appear to have completely novel primary modes of action; retigabine (ezogabine) and perampanel act on the potassium channel and on AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors, respectively. The hope is that antiepileptic drugs with a novel mode of action will be effective where previous drugs have failed and will not have unacceptable adverse effects. However, experience with these medications is too limited to allow any conclusions to be drawn at present.
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Affiliation(s)
- Frank Mc Besag
- South Essex Partnership University NHS Foundation Trust (SEPT), Mid Beds Clinic, Bedford, Bedfordshire, UK ; Institute of Psychiatry, London, UK
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27
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Leppik IE, Patterson EN, Coles LD, Craft EM, Cloyd JC. Canine status epilepticus: a translational platform for human therapeutic trials. Epilepsia 2011; 52 Suppl 8:31-4. [PMID: 21967357 DOI: 10.1111/j.1528-1167.2011.03231.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Current treatment of human status epilepticus (SE) relies on drugs developed for chronic treatment of epilepsy. Many potent compounds have been discovered in animal models of SE. But they may never be useful for chronic treatment of epilepsy and thus not available for human use. Naturally occurring canine SE may become a translational platform for evaluating these compounds for eventual use in human trials. A pilot study of levetiracetam in canine SE demonstrated a 56% response rate compared to 10% for placebo. Based on these results we have obtained an NIH R-21 to further evaluate canine SE as a translational platform for developing new approaches for treating human SE.
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Affiliation(s)
- Ilo E Leppik
- Department of Experimental & Clinical Pharmacology, College of Pharmacy, University of Minnesota, 717 Delaware St SE,Minneapolis, MN 55414, USA.
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28
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Langer M, Brandt C, Löscher W. Marked strain and substrain differences in induction of status epilepticus and subsequent development of neurodegeneration, epilepsy, and behavioral alterations in rats. Epilepsy Res 2011; 96:207-24. [DOI: 10.1016/j.eplepsyres.2011.06.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 05/30/2011] [Accepted: 06/04/2011] [Indexed: 10/18/2022]
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Abstract
In the 1990s there was intense interest in ionotropic glutamate receptors as therapeutic targets for diverse neurological disorders, including epilepsy. NMDA receptors were thought to play a key role in the generation of seizures, leading to clinical studies of NMDA receptor blocking drugs in epilepsy. Disappointing results dampened enthusiasm for ionotropic glutamate receptors as a therapeutic target. Eventually it became appreciated that another type of ionotropic glutamate receptor, the AMPA receptor, is actually the predominant mediator of excitatory neurotransmission in the central nervous system and moreover that AMPA receptors are critical to the generation and spread of epileptic activity. As drugs became available that selectively target AMPA receptors, it was possible to demonstrate that AMPA receptor antagonists have powerful antiseizure activity in in vitro and in vivo models. A decade later, promising clinical studies with AMPA receptor antagonists, including the potent noncompetitive antagonist perampanel, are once again focusing attention on AMPA receptors as a drug target for epilepsy therapy.
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30
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Therapeutic window of opportunity for the neuroprotective effect of valproate versus the competitive AMPA receptor antagonist NS1209 following status epilepticus in rats. Neuropharmacology 2011; 61:1033-47. [PMID: 21736883 DOI: 10.1016/j.neuropharm.2011.06.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 06/16/2011] [Accepted: 06/21/2011] [Indexed: 01/03/2023]
Abstract
Epileptogenesis, i.e., the process leading to epilepsy, is a presumed consequence of brain insults including head trauma, stroke, infections, tumors, status epilepticus (SE), and complex febrile seizures. Typically, brain insults produce morphological and functional alterations in the hippocampal formation, including neurodegeneration in CA1, CA3, and, most consistently, the dentate hilus. Most of these alterations develop gradually, over several days, after the insult, providing a therapeutic window of opportunity for neuroprotective agents in the immediate post-injury period. We have previously reported that prolonged (four weeks) treatment with the antiepileptic drug valproate (VPA) after SE prevents hippocampal damage and most of the behavioral alterations that occur after brain insult, but not the development of spontaneously occurring seizures. These data indicated that VPA, although not preventing epilepsy, might be an effective disease-modifying treatment following brain insult. The present study was designed to (1) determine the therapeutic window for the neuroprotective effect of VPA after SE; (2) compare the efficacy of different intermittent i.p. versus continuous i.v. VPA treatment protocols; and (3) compare VPA with the glutamate (AMPA) receptor antagonist NS1209. As in our previous study with VPA, SE was induced by sustained electrical stimulation of the basolateral amygdala in rats and terminated after 4 h by diazepam. In vehicle controls, >90% of the animals developed significant neurodegeneration in the dentate hilus, whereas damage in CA1 and CA3 was more variable. Hilar parvalbumin-expressing interneurons were more sensitive to the effects of seizures than somatostatin-stained hilar interneurons or hilar mossy cells. Among the various VPA treatment protocols, continuous infusion of VPA for 24 immediately following the SE was the most effective neuroprotective treatment, preventing most of the neuronal damage. Infusion with NS1209 for 24 h exhibited similar neuroprotective efficacy. These data demonstrate that short treatment after SE with either VPA or NS1209 is powerfully neuroprotective, and may be disease-modifying treatments following brain insult.
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31
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Machado-Vieira R, Zarate CA. Proof of concept trials in bipolar disorder and major depressive disorder: a translational perspective in the search for improved treatments. Depress Anxiety 2011; 28:267-81. [PMID: 21456037 PMCID: PMC3071576 DOI: 10.1002/da.20800] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 01/14/2011] [Accepted: 01/24/2011] [Indexed: 11/10/2022] Open
Abstract
A better understanding of the neurobiology of mood disorders, informed by preclinical research and bi-directionally translated to clinical research, is critical for the future development of new and effective treatments. Recently, diverse new targets/compounds have been specifically tested in preclinical models and in proof-of-concept studies, with potential relevance as treatments for mood disorders. Most of the evidence comes from case reports, case series, or controlled proof-of-concept studies, some with small sample sizes. These include (1) the opioid neuropeptide system, (2) the purinergic system, (3) the glutamatergic system, (4) the tachykinin neuropeptide system, (5) the cholinergic system (muscarinic system), and (6) intracellular signaling pathways. These targets may be of substantial interest in defining future directions in drug development, as well as in developing the next generation of therapeutic agents for the treatment of mood disorders. Overall, further study of these and similar drugs may lead to a better understanding of relevant and clinically useful drug targets in the treatment of these devastating illnesses.
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Affiliation(s)
- Rodrigo Machado-Vieira
- Institute and Department of Psychiatry, LIM-27, University of Sao Paulo Medical School, USP, Sao Paulo, SP, Brazil
| | - Carlos A. Zarate
- Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, CRC Unit 7 Southeast, Room 7-3445, Bethesda, Maryland, 20892, USA
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32
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Löscher W, Brandt C. Prevention or modification of epileptogenesis after brain insults: experimental approaches and translational research. Pharmacol Rev 2011; 62:668-700. [PMID: 21079040 DOI: 10.1124/pr.110.003046] [Citation(s) in RCA: 288] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Diverse brain insults, including traumatic brain injury, stroke, infections, tumors, neurodegenerative diseases, and prolonged acute symptomatic seizures, such as complex febrile seizures or status epilepticus (SE), can induce "epileptogenesis," a process by which normal brain tissue is transformed into tissue capable of generating spontaneous recurrent seizures. Furthermore, epileptogenesis operates in cryptogenic causes of epilepsy. In view of the accumulating information about cellular and molecular mechanisms of epileptogenesis, it should be possible to intervene in this process before the onset of seizures and thereby either prevent the development of epilepsy in patients at risk or increase the potential for better long-term outcome, which constitutes a major clinical need. For identifying pharmacological interventions that prevent, interrupt or reverse the epileptogenic process in people at risk, two groups of animal models, kindling and SE-induced recurrent seizures, have been recommended as potentially useful tools. Furthermore, genetic rodent models of epileptogenesis are increasingly used in assessing antiepileptogenic treatments. Two approaches have been used in these different model categories: screening of clinically established antiepileptic drugs (AEDs) for antiepileptogenic or disease-modifying potential, and targeting the key causal mechanisms that underlie epileptogenesis. The first approach indicated that among various AEDs, topiramate, levetiracetam, carisbamate, and valproate may be the most promising. On the basis of these experimental findings, two ongoing clinical trials will address the antiepileptogenic potential of topiramate and levetiracetam in patients with traumatic brain injury, hopefully translating laboratory discoveries into successful therapies. The second approach has highlighted neurodegeneration, inflammation and up-regulation of immune responses, and neuronal hyperexcitability as potential targets for antiepileptogenesis or disease modification. This article reviews these areas of progress and discusses the challenges associated with discovery of antiepileptogenic therapies.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Bünteweg 17, Hannover, Germany.
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Larsen AM, Bunch L. Medicinal chemistry of competitive kainate receptor antagonists. ACS Chem Neurosci 2011; 2:60-74. [PMID: 22778857 DOI: 10.1021/cn1001039] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 11/27/2010] [Indexed: 01/06/2023] Open
Abstract
Kainic acid (KA) receptors belong to the group of ionotropic glutamate receptors and are expressed throughout in the central nervous system (CNS). The KA receptors have been shown to be involved in neurophysiological functions such as mossy fiber long-term potentiation (LTP) and synaptic plasticity and are thus potential therapeutic targets in CNS diseases such as schizophrenia, major depression, neuropathic pain and epilepsy. Extensive effort has been made to develop subtype-selective KA receptor antagonists in order to elucidate the physiological function of each of the five subunits known (GluK1-5). However, to date only selective antagonists for the GluK1 subunit have been discovered, which underlines the strong need for continued research in this area. The present review describes the structure-activity relationship and pharmacological profile for 10 chemically distinct classes of KA receptor antagonists comprising, in all, 45 compounds. To the medicinal chemist this information will serve as reference guidance as well as an inspiration for future effort in this field.
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Affiliation(s)
- Ann M. Larsen
- Department of Medicinal Chemistry, Faculty of Pharmaceutical
Sciences, University of Copenhagen, Universitetsparken 2, DK-2100
Copenhagen, Denmark
| | - Lennart Bunch
- Department of Medicinal Chemistry, Faculty of Pharmaceutical
Sciences, University of Copenhagen, Universitetsparken 2, DK-2100
Copenhagen, Denmark
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34
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Figueiredo TH, Qashu F, Apland JP, Aroniadou-Anderjaska V, Souza AP, Braga MFM. The GluK1 (GluR5) Kainate/{alpha}-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist LY293558 reduces soman-induced seizures and neuropathology. J Pharmacol Exp Ther 2010; 336:303-12. [PMID: 20962029 DOI: 10.1124/jpet.110.171835] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The possibility of mass exposure to nerve agents by a terrorist attack necessitates the availability of antidotes that can be effective against nerve agent toxicity even when administered at a relatively long latency after exposure, because medical assistance may not be immediately available. Nerve agents induce status epilepticus (SE), which can cause brain damage or death. Antagonists of kainate receptors that contain the GluK1 (formerly known as GluR5) subunit (GluK1Rs) are emerging as a new potential treatment for SE and epilepsy from animal research, whereas clinical trials to treat pain have shown that the GluK1/α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist LY293558 [(3S,4aR,6R,8aR)-6-[2-(1(2)H-tetrazole-5-yl)ethyl]decahydroisoquinoline-3-carboxylic acid] is safe and well tolerated. Therefore, we tested whether LY293558 is effective against soman-induced seizures and neuropathology, when administered 1 h after soman exposure, in rats. LY293558 stopped seizures induced by soman and reduced the total duration of SE, monitored by electroencephalographic recordings within a 24 h-period after exposure. In addition, LY293558 prevented neuronal loss in the basolateral amygdala (BLA) and the CA1 hippocampal area on both days 1 and 7 after soman exposure and reduced neuronal degeneration in the CA1, CA3, and hilar hippocampal regions, entorhinal cortex, amygdala, and neocortex on day 1 after exposure and in the CA1, CA3, amygdala, and neocortex on day 7 after exposure. It also prevented the delayed loss of glutamic acid decarboxylase-67 immuno-stained BLA interneurons on day 7 after exposure. LY293558 is a potential new emergency treatment for nerve agent exposure that can be expected to be effective against seizures and brain damage even with late administration.
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Affiliation(s)
- Taiza H Figueiredo
- Department of Anatomy, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
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Mattes H, Carcache D, Kalkman HO, Koller M. alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) antagonists: from bench to bedside. J Med Chem 2010; 53:5367-82. [PMID: 20356304 DOI: 10.1021/jm901688m] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Henri Mattes
- Novartis Pharma AG, Werk Klybeck, WKL-122-241 Postfach, CH-4002 Basel, Switzerland.
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The AMPA receptor as a therapeutic target: current perspectives and emerging possibilities. Future Med Chem 2010; 2:877-91. [DOI: 10.4155/fmc.10.27] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) is a subtype of the ionotropic glutamate receptors that plays a prominent role in neurotransmission and is widespread throughout the CNS. Because of this, its malfunction can result in a multitude of nervous system diseases. This review looks at compounds that are able to modulate AMPAR function by binding to one of several sites on the receptor that either downregulate its function (competitive, noncompetitive and uncompetitive antagonists) or upregulate its function (positive modulators). It will also give an account of the various diseases that have implicated AMPAR dysfunction and how specific types of AMPAR modulator may be beneficial in their treatment. The AMPAR remains an unexploited but important therapeutic target.
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Fritsch B, Stott JJ, Donofrio JJ, Rogawski MA. Treatment of early and late kainic acid-induced status epilepticus with the noncompetitive AMPA receptor antagonist GYKI 52466. Epilepsia 2010; 51:108-17. [PMID: 19682025 PMCID: PMC4535693 DOI: 10.1111/j.1528-1167.2009.02205.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE Benzodiazepines such as diazepam may fail to effectively treat status epilepticus because benzodiazepine-sensitive GABA(A) receptors are progressively internalized with continued seizure activity. Ionotropic glutamate receptors, including AMPA receptors, are externalized, so that AMPA receptor antagonists, which are broad-spectrum anticonvulsants, could be more effective treatments for status epilepticus. We assessed the ability of the noncompetitive AMPA receptor antagonist GYKI 52466 to protect against kainic acid-induced status epilepticus in mice. METHODS Groups of animals treated with kainic acid received GYKI 52466 (50 mg/kg followed in 15 min by 50 mg/kg) or diazepam (25 mg/kg followed in 20 min by 12.5 mg/kg) beginning at 5 min of continuous seizure activity or 25 min later. The duration of seizure activity was determined by EEG recording from epidural cortical electrodes. RESULTS Both GYKI 52466 and diazepam rapidly terminated electrographic and behavioral seizures when administered early. However, diazepam-treated animals exhibited more seizure recurrences. With late administration, GYKI 52466 also rapidly terminated seizures and they seldom recurred, whereas diazepam was slow to produce seizure control and recurrences were common. Although both treatments caused sedation, GYKI 52466-treated animals retained neurological responsiveness whereas diazepam-treated animals did not. GYKI 52466 did not affect blood pressure whereas diazepam caused a sustained drop in mean arterial pressure. DISCUSSION Noncompetitive AMPA receptor antagonists represent a promising approach for early treatment of status epilepticus; they may also be effective at later times when there is refractoriness to benzodiazepines.
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Affiliation(s)
- Brita Fritsch
- Epilepsy Research Section, National Institute for Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A
- Department of Neurology, University of Freiburg, Freiburg, Germany
| | - Jeffrey J. Stott
- Epilepsy Research Section, National Institute for Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A
| | - Joy Joelle Donofrio
- Epilepsy Research Section, National Institute for Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A
| | - Michael A. Rogawski
- Epilepsy Research Section, National Institute for Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, U.S.A
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, California, U.S.A
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Machado-Vieira R, Manji HK, Zarate CA. Potential novel therapeutics for bipolar disorders. Curr Top Behav Neurosci 2010; 5:303-29. [PMID: 25236562 DOI: 10.1007/7854_2010_51] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Existing pharmacological treatments for bipolar disorder (BPD), a severe recurrent mood disorder, are in general insufficient for many patients. Despite adequate doses and treatment duration, many individuals with this disease continue to experience mood episode relapses, residual symptoms, and functional impairment. This chapter reviews a number of targets/compounds that could result in putative novel treatments for BPD, including the dynorphin opioid neuropeptide system, the glutamatergic system, the purinergic system, the cholinergic system (muscarinic and nicotinic systems), the oxidative stress system, and the melatonergic system. The arachidonic acid cascade and intracellular signaling cascades (including glycogen synthase kinase 3 and protein kinase C) are also reviewed, as are agents that affect multiple targets (e.g., modafinil, Uridine RG2417). Further study of these and similar agents may improve our understanding of relevant drug targets and their clinical utility as potential therapeutics for this devastating disorder.
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Affiliation(s)
- Rodrigo Machado-Vieira
- Experimental Therapeutics, Mood and Anxiety Disorders Research Program, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Mark O. Hatfield CRC, Unit 7 SE, Rm. 7-3445, Bethesda, MD, 20892, USA,
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Perucca E. What is the promise of new antiepileptic drugs in status epilepticus? Focus on brivaracetam, carisbamate, lacosamide, NS-1209, and topiramate. Epilepsia 2009; 50 Suppl 12:49-50. [DOI: 10.1111/j.1528-1167.2009.02366.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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van Raay L, Morris MJ, Reed RC, O’Brien TJ, Dedeurwaerdere S. A novel system allowing long-term simultaneous video-electroencephalography recording, drug infusion and blood sampling in rats. J Neurosci Methods 2009; 179:184-90. [DOI: 10.1016/j.jneumeth.2009.01.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 01/23/2009] [Accepted: 01/26/2009] [Indexed: 10/21/2022]
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