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Mareš P. Epilepsy Research in the Institute of Physiology of the Czech Academy of Sciences in Prague. Physiol Res 2024; 73:S67-S82. [PMID: 38752773 DOI: 10.33549/physiolres.935391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024] Open
Abstract
Starting from simple clinical statistics, the spectrum of methods used in epilepsy research in the Institute of Physiology of the Czechoslovak (now Czech) Academy of Sciences progressively increased. Professor Servít used electrophysiological methods for study of brain activity in lower vertebrates, neuropathology was focused on electronmicroscopic study of cortical epileptic focus and ion-sensitive microelectrodes were used for studies of cortical direct current potentials. Developmental studies used electrophysiological methods (activity and projection of cortical epileptic foci, EEG under the influence of convulsant drugs, hippocampal, thalamic and cortical electrical stimulation for induction of epileptic afterdischarges and postictal period). Extensive pharmacological studies used seizures elicited by convulsant drugs (at first pentylenetetrazol but also other GABA antagonists as well as agonists of glutamate receptors). Motor performance and behavior were also studied during brain maturation. The last but not least molecular biology was included into the spectrum of methods. Many original data were published making a background of position of our laboratory in the first line of laboratories interested in brain development.
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Affiliation(s)
- P Mareš
- Laboratory of Developmental Epileptology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
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Lattanzi S, Riva A, Striano P. Ganaxolone treatment for epilepsy patients: from pharmacology to place in therapy. Expert Rev Neurother 2021; 21:1317-1332. [PMID: 33724128 DOI: 10.1080/14737175.2021.1904895] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Introduction: Nonsulfated neurosteroids can provide phasic and tonic inhibition through activation of synaptic and extra-synaptic γ-aminobutyric acid (GABA)A receptors, exhibiting a greater potency for the latter. These actions occur by interacting with modulatory sites that are distinct from those bound by benzodiazepines and barbiturates. Ganaxolone (GNX) is a synthetic analog of the endogenous neurosteroid allopregnanolone and a member of a novel class of neuroactive steroids called epalons.Areas covered: The authors review the pharmacology of GNX, summarize the main clinical evidence about its antiseizure efficacy and tolerability, and suggest implications for clinical practice and future research.Expert opinion: The clinical development of GNX is mainly oriented to target unmet needs and focused on status epilepticus and rare genetic epilepsies that have few or no treatment options.The availability of oral and intravenous formulations allows reaching adult and pediatric patients in acute and chronic care settings. Further evidence will complement the understanding of the potentialities of GNX and possibly lead to indications for use in clinical practice.
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Affiliation(s)
- Simona Lattanzi
- Neurological Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Antonella Riva
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, "G. Gaslini" Institute, University of Genoa, Genova, Italy
| | - Pasquale Striano
- Pediatric Neurology and Muscular Diseases Unit, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, "G. Gaslini" Institute, University of Genoa, Genova, Italy
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Miziak B, Chrościńska-Krawczyk M, Czuczwar SJ. Neurosteroids and Seizure Activity. Front Endocrinol (Lausanne) 2020; 11:541802. [PMID: 33117274 PMCID: PMC7561372 DOI: 10.3389/fendo.2020.541802] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 09/09/2020] [Indexed: 12/13/2022] Open
Abstract
Still circa 25% to 30% of patients with epilepsy cannot be efficiently controlled with available antiepileptic drugs so newer pharmacological treatment options have been continuously searched for. In this context, a group of endogenous or exogenous neurosteroids allosterically positively modulating GABA-A receptors may offer a promising approach. Among endogenous neurosteroids synthesized in the brain, allopregnanolone or allotetrahydrodeoxycorticosterone have been documented to exert anticonvulsant activity in a number of experimental models of seizures-pentylenetetrazol-, bicuculline- pilocarpine-, or 6 Hz-induced convulsions in rodents. Neurosteroids can also inhibit fully kindled seizures and some of them have been reported to counteract maximal electroshock-induced convulsions. An exogenous neurosteroid, alphaxalone, significantly elevated the threshold for maximal electroconvulsions in mice but it did not potentiate the anticonvulsive action of a number of conventional antiepileptic drugs against maximal electroshock-induced seizures. Androsterone not only elevated the threshold but significantly enhanced the protective action of carbamazepine, gabapentin and phenobarbital against maximal electroshock in mice, as well. Ganaxolone (a 3beta-methylated analog of allopregnanolone) needs special consideration for two reasons. First, it performed better than conventional antiepileptic drugs, diazepam or valproate, in suppressing convulsive and lethal effects of pentylenetetrazol in pentylenetetrazol-kindled mice. Second, ganaxolone has been evaluated in the randomized, double-blind, placebo-controlled phase 2 trial in patients with intractable partial seizures, taking maximally 3 antiepileptic drugs. The initial results indicate that add-on therapy with ganaxolone resulted in reduced seizure frequency with adverse effect being mainly mild to moderate. Possibly, ganaxolone may be also considered against catamenial seizures. Some positive effects of ganaxolone as an adjuvant were also observed in children with refractory seizures and its use may also prove efficient for the management of neonatal seizures associated with hypoxic injury. Neurosteroids positively modulating GABA-A receptor complex exert anticonvulsive activity in many experimental models of seizures. Their interactions with antiepileptic drugs seem ambiguous in mice. Initial clinical data indicate that ganaxolone may provide a better seizure control in patients with drug-resistant epilepsy.
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Affiliation(s)
- Barbara Miziak
- Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
| | | | - Stanisław J. Czuczwar
- Department of Pathophysiology, Medical University of Lublin, Lublin, Poland
- *Correspondence: Stanisław J. Czuczwar,
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Saporito MS, Gruner JA, DiCamillo A, Hinchliffe R, Barker-Haliski M, White HS. Intravenously Administered Ganaxolone Blocks Diazepam-Resistant Lithium-Pilocarpine–Induced Status Epilepticus in Rats: Comparison with Allopregnanolone. J Pharmacol Exp Ther 2018; 368:326-337. [DOI: 10.1124/jpet.118.252155] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 12/12/2018] [Indexed: 11/22/2022] Open
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Greco M, Varriale G, Coppola G, Operto F, Verrotti A, Iezzi ML. Investigational small molecules in phase II clinical trials for the treatment of epilepsy. Expert Opin Investig Drugs 2018; 27:971-979. [DOI: 10.1080/13543784.2018.1543398] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Marco Greco
- Department of Pediatrics, University of L’Aquila, L’Aquila, Italy
| | - Gaia Varriale
- Department of Pediatrics, University of L’Aquila, L’Aquila, Italy
| | - Giangennaro Coppola
- Child and Adolescent Neuropsychiatry, Medical School, University of Salerno, Salerno, Italy
| | - Francesca Operto
- Child and Adolescent Neuropsychiatry, Medical School, University of Salerno, Salerno, Italy
| | - Alberto Verrotti
- Department of Pediatrics, University of L’Aquila, L’Aquila, Italy
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Mareš P. Participation of GABA B receptors in cortical postictal excitability in immature rats. Eur J Pharmacol 2018; 818:26-29. [PMID: 29032104 DOI: 10.1016/j.ejphar.2017.10.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 10/05/2017] [Accepted: 10/12/2017] [Indexed: 11/29/2022]
Abstract
Arrest of seizures is due to an active inhibition and is followed in mature brain by period of refractoriness markedly present one min after the end of seizures. To study changes in cortical excitability after epileptic seizures we used electrical stimulation of sensorimotor cortical area in immature rats - 25-day-old ones with mature postictal refractoriness and 12-day-old where postictal potentiation of afterdischarges (ADs) is present instead of refractoriness at one minute after the end of the conditioning AD. GABAB receptor antagonist CGP35348 was found to partly suppress postictal refractoriness. In present study not only an antagonist CGP46381 (3 and 10mg/kg i.p.) but also positive allosteric modulator of GABAB receptors CGP7930 (20 and 40mg/kg i.p.) were used to study the role of GABAB receptors in both age groups. They were injected immediately after testing AD and 10min later the two stimulations were repeated. CGP46381 partly antagonized postictal refractoriness in 25-day-old rats but did not significantly affect ADs in 12-day-old animals. CGP7930 did not significantly change ADs duration in either age group. GABAB receptors participate in mechanism of postictal refractoriness but did not play an important role in 12-day-old rats where potentiation instead of refractoriness is present.
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Affiliation(s)
- Pavel Mareš
- Department of Developmental Epileptology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic.
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Yawno T, Miller SL, Bennet L, Wong F, Hirst JJ, Fahey M, Walker DW. Ganaxolone: A New Treatment for Neonatal Seizures. Front Cell Neurosci 2017; 11:246. [PMID: 28878622 PMCID: PMC5572234 DOI: 10.3389/fncel.2017.00246] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 08/02/2017] [Indexed: 12/11/2022] Open
Abstract
Neonatal seizures are amongst the most common neurologic conditions managed by a neonatal care service. Seizures can exacerbate existing brain injury, induce “de novo” injury, and are associated with neurodevelopmental disabilities in post-neonatal life. In this mini-review, we present evidence in support of the use of ganaxolone, a GABAA agonist neurosteroid, as a novel neonatal therapy. We discuss evidence that ganaxolone can provide both seizure control and neuroprotection with a high safety profile when administered early following birth-related hypoxia, and show evidence that it is likely to prevent or reduce the incidence of the enduring disabilities associated with preterm birth, cerebral palsy, and epilepsy. We suggest that ganaxolone is an ideal anti-seizure treatment because it can be safely used prospectively, with minimal or no adverse effects on the neonatal brain.
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Affiliation(s)
- Tamara Yawno
- Ritchie Centre, Hudson Institute of Medical ResearchClayton, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash UniversityClayton, VIC, Australia
| | - Suzie L Miller
- Ritchie Centre, Hudson Institute of Medical ResearchClayton, VIC, Australia.,Department of Obstetrics and Gynaecology, Monash UniversityClayton, VIC, Australia
| | - Laura Bennet
- Department of Physiology, The University of AucklandAuckland, New Zealand
| | - Flora Wong
- Ritchie Centre, Hudson Institute of Medical ResearchClayton, VIC, Australia.,Department of Paediatrics, Monash UniversityClayton, VIC, Australia
| | - Jonathan J Hirst
- School of Biomedical Sciences and Pharmacy, University of NewcastleCallaghan, NSW, Australia
| | - Michael Fahey
- Department of Paediatrics, Monash UniversityClayton, VIC, Australia
| | - David W Walker
- Ritchie Centre, Hudson Institute of Medical ResearchClayton, VIC, Australia.,School of Health and Biomedical Sciences, RMIT UniversityBundoora, VIC, Australia
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Ciarlone SL, Wang X, Rogawski MA, Weeber EJ. Effects of the synthetic neurosteroid ganaxolone on seizure activity and behavioral deficits in an Angelman syndrome mouse model. Neuropharmacology 2016; 116:142-150. [PMID: 27986596 DOI: 10.1016/j.neuropharm.2016.12.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/02/2016] [Accepted: 12/12/2016] [Indexed: 11/25/2022]
Abstract
Angelman syndrome (AS) is a rare neurogenetic disorder characterized by severe developmental delay, motor impairments, and epilepsy. GABAergic dysfunction is believed to contribute to many of the phenotypic deficits seen in AS. We hypothesized that restoration of inhibitory tone mediated by extrasynaptic GABAA receptors could provide therapeutic benefit. Here, we report that ganaxolone, a synthetic neurosteroid that acts as a positive allosteric modulator of synaptic and extrasynaptic GABAA receptors, was anxiolytic, anticonvulsant, and improved motor deficits in the Ube3a-deficient mouse model of AS when administered by implanted mini-pump for 3 days or 4 weeks. Treatment for 4 weeks also led to recovery of spatial working memory and hippocampal synaptic plasticity deficits. This study demonstrates that ganaxolone ameliorates many of the behavioral abnormalities in the adult AS mouse, and tolerance did not occur to the therapeutic effects of the drug. The results support clinical studies to investigate ganaxolone as a symptomatic treatment for AS.
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Affiliation(s)
- Stephanie L Ciarlone
- USF Health Byrd Alzheimer's Institute, Tampa, FL, USA; Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Xinming Wang
- USF Health Byrd Alzheimer's Institute, Tampa, FL, USA
| | - Michael A Rogawski
- Departments of Neurology and Pharmacology, School of Medicine, University of California, Davis, Sacramento, CA, USA
| | - Edwin J Weeber
- USF Health Byrd Alzheimer's Institute, Tampa, FL, USA; Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA.
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Kasal A, Buděšínský M, Mareš P, Krištofíková Z, Leitão AJ, Sá e Melo ML, Silva MMC. Neurosteroids: Can a 2alpha,3alpha-epoxy ring make up for the 3alpha-hydroxyl group? Steroids 2016; 105:12-8. [PMID: 26631551 DOI: 10.1016/j.steroids.2015.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 11/06/2015] [Accepted: 11/19/2015] [Indexed: 10/22/2022]
Abstract
Seven steroid epoxides were prepared from 5α-pregn-2-en-20-one and 5α-pregn-3-en-20-one and their side-chain derivatives. All compounds were tested in vitro for binding to γ-aminobutyric acid (GABAA) receptor, some of them also in vivo for anticonvulsant action. 2α,3α-Epoxy-5α-pregnan-20-one inhibited the TBPS binding to the GABAA receptor and showed a moderate anticonvulsant action in immature rats. In contrast, its 3α,4α-isomer was inactive. More polar epoxide derivatives, modified at the side chain were less active or inactive. Noteworthy, diol 20, the product of trans-diaxial opening of the 2α,3α-epoxide 4, was not able to inhibit the TBPS binding, showing that the activity of the epoxide is due to the compound itself and not to its hydrolytic product. The 3α-hydroxyl group is known to be essential for the GABAA receptor binding. Despite the shortness of in vivo effects which are probably due to metabolic inactivation of the products prepared, our results show that the 2α,3α-epoxy ring is another structural pattern with ability to bind the GABAAR.
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Affiliation(s)
- Alexander Kasal
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Prague CZ16610, Czech Republic.
| | - Miloš Buděšínský
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Prague CZ16610, Czech Republic
| | - Pavel Mareš
- Institute of Physiology, Academy of Sciences, CZ14220 Prague 4, Czech Republic
| | - Zdena Krištofíková
- Alzheimer's Disease Center, National Institute of Mental Health, Klecany CZ25067, Czech Republic
| | - Alcino J Leitão
- Faculdade de Farmácia, Universidade de Coimbra, 3000-508 Coimbra, Portugal; CNC - Centre for Neurosciences and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Maria Luisa Sá e Melo
- Faculdade de Farmácia, Universidade de Coimbra, 3000-508 Coimbra, Portugal; CNC - Centre for Neurosciences and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Maria Manuel C Silva
- Faculdade de Farmácia, Universidade de Coimbra, 3000-508 Coimbra, Portugal; CNC - Centre for Neurosciences and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
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Dhir A, Chopra K. On the anticonvulsant effect of allopregnanolone (a neurosteroid) in neonatal rats. Life Sci 2015; 143:202-8. [DOI: 10.1016/j.lfs.2015.09.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 08/03/2015] [Accepted: 09/15/2015] [Indexed: 11/29/2022]
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Mareš P, Tichá K, Mikulecká A. Anticonvulsant and behavioral effects of muscimol in immature rats. Brain Res 2014; 1582:227-36. [PMID: 25084038 DOI: 10.1016/j.brainres.2014.07.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 07/21/2014] [Accepted: 07/23/2014] [Indexed: 10/25/2022]
Abstract
Potentiation of GABAergic inhibition is a mechanism of action of many antiepileptic drugs. The potential use of an agonist of GABAA receptors, muscimol, as an antiepileptic drug was studied in immature rats by assessing anticonvulsant activity and side effects on motor activities. Anticonvulsant action was tested in two models of seizures (pentetrazol-induced convulsions and cortical epileptic afterdischarges). Off target effect on motor performance was assessed in a battery of tests and in the open field in three age groups (12-, 18- and 25-day-old rats). Muscimol was administered in doses from 0.1 to 1mg/kg i.p. Only the 1 mg/kg dose exhibited marked anticonvulsant effect against pentetrazol-induced convulsions in 12- and 18-day-old rats, proconvulsant effect was observed in the second model in 18- and 25-day-old rats as prolongation of afterdischarges. Even the 0.5 mg/kg dose suppressed spontaneous locomotion and heavily compromised motor performance. The effect on motor activity was marked in the youngest group and decreased with age. Due to the low anticonvulsant potency and serious side effects, systemic administration of a competitive agonist of GABAA receptors in immature animals is not a promising strategy for new anticonvulsants.
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Affiliation(s)
- Pavel Mareš
- Department of Developmental Epileptology, Institute of Physiology, Academy of Sciences, Czech Republic.
| | - Kateřina Tichá
- Department of Developmental Epileptology, Institute of Physiology, Academy of Sciences, Czech Republic; Charles University, 2nd Medical Faculty, Prague, Czech Republic
| | - Anna Mikulecká
- Department of Developmental Epileptology, Institute of Physiology, Academy of Sciences, Czech Republic
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Blauwblomme T, Jiruska P, Huberfeld G. Mechanisms of ictogenesis. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2014; 114:155-85. [PMID: 25078502 DOI: 10.1016/b978-0-12-418693-4.00007-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Epilepsy is a paroxysmal condition characterized by repeated transient seizures separated by longer interictal periods. Ictogenesis describes the processes of transition from the interictal state to a seizure. The processes include a preictal state, with specific clinical signs and a distinct electrophysiology which may provide opportunities to anticipate, or even prevent, seizures. Biological mechanisms of ictogenesis remain poorly understood and may vary between conditions/syndromes. We review here ictogenic processes including the involvement of pyramidal cells, interneurons and astrocytes, GABAergic and glutamatergic signaling, and ionic perturbations. Our review suggests that specific excitatory influences at the transition to an ictal event include (1) GABA receptor activation with a neuronal Cl(-) load and (2) a transient increase in external K(+).
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Affiliation(s)
- Thomas Blauwblomme
- Neurosurgery Unit, Hopital Necker-Enfants Malades, APHP, Paris, France; Université Paris Descartes, Paris, France; INSERM U1129-Infantile Epilepsies and Brain Plasticity, Paris, France; University Paris Descartes, PRES Sorbonne Paris Cité, Paris, France; CEA, Gif sur Yvette, France
| | - Premysl Jiruska
- Department of Developmental Epileptology, Institute of Physiology, Academy of Sciences of Czech Republic, Prague, Czech Republic; Department of Neurology, 2nd Faculty of Medicine, Charles University in Prague, Motol University Hospital, Prague, Czech Republic
| | - Gilles Huberfeld
- INSERM U1129-Infantile Epilepsies and Brain Plasticity, Paris, France; University Paris Descartes, PRES Sorbonne Paris Cité, Paris, France; CEA, Gif sur Yvette, France; Clinical Neurophysiology Department, CHU Pitié-Salpêtrière, APHP, Paris, France; Université Pierre et Marie Curie, Paris, France.
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Mishra RK, Baker MT. ortho Substituent effects on the anticonvulsant properties of 4-hydroxy-trifluoroethyl phenols. Bioorg Med Chem Lett 2012; 22:5608-11. [DOI: 10.1016/j.bmcl.2012.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 06/28/2012] [Accepted: 07/02/2012] [Indexed: 11/30/2022]
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