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Wada K, Sonoda M, Firestone E, Sakakura K, Kuroda N, Takayama Y, Iijima K, Iwasaki M, Mihara T, Goto T, Asano E, Miyazaki T. Sevoflurane-based enhancement of phase-amplitude coupling and localization of the epileptogenic zone. Clin Neurophysiol 2022; 134:1-8. [PMID: 34922194 PMCID: PMC8766927 DOI: 10.1016/j.clinph.2021.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 10/05/2021] [Accepted: 11/03/2021] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Phase-amplitude coupling between high-frequency (≥150 Hz) and delta (3-4 Hz) oscillations - modulation index (MI) - is a promising, objective biomarker of epileptogenicity. We determined whether sevoflurane anesthesia preferentially enhances this metric within the epileptogenic zone. METHODS This is an observational study of intraoperative electrocorticography data from 621 electrodes chronically implanted into eight patients with drug-resistant, focal epilepsy. All patients were anesthetized with sevoflurane during resective surgery, which subsequently resulted in seizure control. We classified 'removed' and 'retained' brain sites as epileptogenic and non-epileptogenic, respectively. Mixed model analysis determined which anesthetic stage optimized MI-based classification of epileptogenic sites. RESULTS MI increased as a function of anesthetic stage, ranging from baseline (i.e., oxygen alone) to 2.0 minimum alveolar concentration (MAC) of sevoflurane, preferentially at sites showing higher initial MI values. This phenomenon was accentuated just prior to sevoflurane reaching 2.0 MAC, at which time, the odds of a site being classified as epileptogenic were enhanced by 86.6 times for every increase of 1.0 MI. CONCLUSIONS Intraoperative MI best localized the epileptogenic zone immediately before sevoflurane reaching 2.0 MAC in this small cohort of patients. SIGNIFICANCE Prospective, large cohort studies are warranted to determine whether sevoflurane anesthesia can reduce the need for extraoperative, invasive evaluation.
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Affiliation(s)
- Keiko Wada
- Department of Anesthesiology, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo 1878551, Japan,Department of Anesthesiology and Critical Care, Yokohama City University Graduate School of Medicine, Yokohama, 2360004, Japan
| | - Masaki Sonoda
- Department of Pediatrics, Children’s Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI 48201, USA,Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 2360004, Japan
| | - Ethan Firestone
- Department of Pediatrics, Children’s Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI 48201, USA,Department of Physiology, Wayne State University, Detroit, MI 48201, USA
| | - Kazuki Sakakura
- Department of Pediatrics, Children’s Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI 48201, USA,Department of Neurosurgery, University of Tsukuba, Tsukuba, 3058575, Japan
| | - Naoto Kuroda
- Department of Pediatrics, Children’s Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI 48201, USA,Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai 9808575, Japan
| | - Yutaro Takayama
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama 2360004, Japan,Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo 1878551, Japan
| | - Keiya Iijima
- Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo 1878551, Japan
| | - Masaki Iwasaki
- Department of Neurosurgery, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira, Tokyo 1878551, Japan
| | - Takahiro Mihara
- Department of Anesthesiology and Critical Care, Yokohama City University Graduate School of Medicine, Yokohama, 2360004, Japan,Department of Health Data Science, Yokohama City University Graduate School of Data Science, Yokohama, 2360027, Japan
| | - Takahisa Goto
- Department of Anesthesiology and Critical Care, Yokohama City University Graduate School of Medicine, Yokohama, 2360004, Japan
| | - Eishi Asano
- Department of Pediatrics, Children’s Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI 48201, USA,Department of Neurology, Children’s Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI 48201, USA,E.A. and T.M. share the senior authorship. Corresponding Authors: Eishi Asano, M.D., Ph.D., M.S. (C.R.D.S.A.), Address: Division of Pediatric Neurology, Children’s Hospital of Michigan, Wayne State University. 3901 Beaubien St., Detroit, MI, 48201, USA, Phone: +1-313-745-5547, FAX: +1-313-745-9435, and Tomoyuki Miyazaki, M.D., Ph.D., Address: Department of Physiology/Anesthesiology, Yokohama City University Graduate School of Medicine. 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan, Phone: +81-45-787-2918, FAX: +81-45-787-2917,
| | - Tomoyuki Miyazaki
- Department of Anesthesiology and Critical Care, Yokohama City University Graduate School of Medicine, Yokohama, 2360004, Japan,Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama 2360004, Japan,E.A. and T.M. share the senior authorship. Corresponding Authors: Eishi Asano, M.D., Ph.D., M.S. (C.R.D.S.A.), Address: Division of Pediatric Neurology, Children’s Hospital of Michigan, Wayne State University. 3901 Beaubien St., Detroit, MI, 48201, USA, Phone: +1-313-745-5547, FAX: +1-313-745-9435, and Tomoyuki Miyazaki, M.D., Ph.D., Address: Department of Physiology/Anesthesiology, Yokohama City University Graduate School of Medicine. 3-9 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, Japan, Phone: +81-45-787-2918, FAX: +81-45-787-2917,
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Fukuda A. Chloride homeodynamics underlying modal shifts in cellular and network oscillations. Neurosci Res 2020; 156:14-23. [PMID: 32105770 DOI: 10.1016/j.neures.2020.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 11/22/2019] [Accepted: 02/21/2020] [Indexed: 11/16/2022]
Abstract
γ-Aminobutyric acid (GABA) generally induces hyperpolarization and inhibition in the adult brain, but causes depolarization (and can be excitatory) in the immature brain. Depolarizing GABA actions are necessary for neurogenesis, differentiation, migration, and synaptogenesis. Additionally, the conversion of GABA responses from inhibition to excitation can be induced in adults by pathological conditions. Because GABAA receptors are Cl- channels, alternating GABA actions between hyperpolarization (Cl- influx) and depolarization (Cl- efflux) are induced by changes in the Cl- gradient, which is regulated by C- transporters. Thus, the dynamics of neural functions are modulated by active Cl- homeostasis (Cl- homeodynamics), alternating inhibition and excitation, and could underlie the modal shifts in cellular and network oscillations. Such a modal shift in GABA actions is required for normal development. Thus disturbances in this developmental GABA modal shift and/or the induction of excitatory GABA action in adult could underlie the pathogenesis of diverse neurological diseases (so-called network diseases).
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Affiliation(s)
- Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu, Japan; Advanced Research Facilities and Services, Preeminent Medical Photonics Education and Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan.
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3
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Cheng H, Wang Y, Chen J, Chen Z. The piriform cortex in epilepsy: What we learn from the kindling model. Exp Neurol 2020; 324:113137. [DOI: 10.1016/j.expneurol.2019.113137] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 12/14/2022]
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Early Life Inflammation Increases CA1 Pyramidal Neuron Excitability in a Sex and Age Dependent Manner through a Chloride Homeostasis Disruption. J Neurosci 2019; 39:7244-7259. [PMID: 31308096 DOI: 10.1523/jneurosci.2973-18.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 05/31/2019] [Accepted: 07/04/2019] [Indexed: 02/07/2023] Open
Abstract
Early life, systemic inflammation causes long-lasting changes in behavior. To unmask possible mechanisms associated with this phenomenon, we asked whether the intrinsic membrane properties in hippocampal neurons were altered as a consequence of early life inflammation. C57BL/6 mice were bred in-house and both male and female pups from multiple litters were injected with lipopolysaccharide (LPS; 100 μg/kg, i.p.) or vehicle at postnatal day (P)14, and kept until adolescence (P35-P45) or adulthood (P60-P70), when brain slices were prepared for whole-cell and perforated-patch recordings from CA1 hippocampal pyramidal neurons. In neurons of adult male mice pretreated with LPS, the number of action potentials elicited by depolarizing current pulses was significantly increased compared with control neurons, concomitant with increased input resistance, and a lower action potential threshold. Although these changes were not associated with changes in relevant sodium channel expression or differences in capacitance or dendritic architecture, they were linked to a mechanism involving intracellular chloride overload, revealed through a depolarized GABA reversal potential and increased expression of the chloride transporter, NKCC1. In contrast, no significant changes were observed in neurons of adult female mice pretreated with LPS, nor in adolescent mice of either sex. These data uncover a potential mechanism involving neonatal inflammation-induced plasticity in chloride homeostasis, which may contribute to early life inflammation-induced behavioral alterations.SIGNIFICANCE STATEMENT Early life inflammation results in long-lasting changes in many aspects of adult physiology. In this paper we reveal that a brief exposure to early life peripheral inflammation with LPS increases excitability in hippocampal neurons in a sex- and age-dependent manner through a chloride homeostasis disruption. As this hyperexcitability was only seen in adult males, and not in adult females or adolescent animals of either sex, it raises the possibility of a hormonal interaction with early life inflammation. Furthermore, as neonatal inflammation is a normal feature of early life in most animals, as well as humans, these findings may be very important for the development of animal models of disease that more appropriately resemble the human condition.
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Kharod SC, Kang SK, Kadam SD. Off-Label Use of Bumetanide for Brain Disorders: An Overview. Front Neurosci 2019; 13:310. [PMID: 31068771 PMCID: PMC6491514 DOI: 10.3389/fnins.2019.00310] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/19/2019] [Indexed: 01/17/2023] Open
Abstract
Bumetanide (BTN or BUM) is a FDA-approved potent loop diuretic (LD) that acts by antagonizing sodium-potassium-chloride (Na-K-Cl) cotransporters, NKCC1 (SLc12a2) and NKCC2. While NKCC1 is expressed both in the CNS and in systemic organs, NKCC2 is kidney-specific. The off-label use of BTN to modulate neuronal transmembrane Cl− gradients by blocking NKCC1 in the CNS has now been tested as an anti-seizure agent and as an intervention for neurological disorders in pre-clinical studies with varying results. BTN safety and efficacy for its off-label use has also been tested in several clinical trials for neonates, children, adolescents, and adults. It failed to meet efficacy criteria for hypoxic-ischemic encephalopathy (HIE) neonatal seizures. In contrast, positive outcomes in temporal lobe epilepsy (TLE), autism, and schizophrenia trials have been attributed to BTN in studies evaluating its off-label use. NKCC1 is an electroneutral neuronal Cl− importer and the dominance of NKCC1 function has been proposed as the common pathology for HIE seizures, TLE, autism, and schizophrenia. Therefore, the use of BTN to antagonize neuronal NKCC1 with the goal to lower internal Cl− levels and promote GABAergic mediated hyperpolarization has been proposed. In this review, we summarize the data and results for pre-clinical and clinical studies that have tested off-label BTN interventions and report variable outcomes. We also compare the data underlying the developmental expression profile of NKCC1 and KCC2, highlight the limitations of BTN’s brain-availability and consider its actions on non-neuronal cells.
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Affiliation(s)
- Shivani C Kharod
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States
| | - Seok Kyu Kang
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States
| | - Shilpa D Kadam
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States.,Department of Neurology and Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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Wang Y, Wang Y, Chen Z. Double-edged GABAergic synaptic transmission in seizures: The importance of chloride plasticity. Brain Res 2018; 1701:126-136. [PMID: 30201259 DOI: 10.1016/j.brainres.2018.09.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 09/04/2018] [Accepted: 09/06/2018] [Indexed: 12/18/2022]
Abstract
GABAergic synaptic inhibition, which is a critical regulator of neuronal excitability, is closely involved in epilepsy. Interestingly, fast GABAergic transmission mediated by Cl- permeable GABAA receptors can bi-directionally exert both seizure-suppressing and seizure-promoting actions. Accumulating evidence suggests that chloride plasticity, the driving force of GABAA receptor-mediated synaptic transmission, contributes to the double-edged role of GABAergic synapses in seizures. Large amounts of Cl- influx can overwhelm Cl- extrusion during seizures not only in healthy tissue in a short-term "activity-dependent" manner, but also in chronic epilepsy in a long-term, irreversible "pathology-dependent" manner related to the dysfunction of two chloride transporters: the chloride importer NKCC1 and the chloride exporter KCC2. In this review, we address the importance of chloride plasticity for the "activity-dependent" and "pathology-dependent" mechanisms underlying epileptic events and provide possible directions for further research, which may be clinically important for the design of GABAergic synapse-targeted precise therapeutic interventions for epilepsy.
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Affiliation(s)
- Ying Wang
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yi Wang
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
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7
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Brandt C, Seja P, Töllner K, Römermann K, Hampel P, Kalesse M, Kipper A, Feit PW, Lykke K, Toft-Bertelsen TL, Paavilainen P, Spoljaric I, Puskarjov M, MacAulay N, Kaila K, Löscher W. Bumepamine, a brain-permeant benzylamine derivative of bumetanide, does not inhibit NKCC1 but is more potent to enhance phenobarbital's anti-seizure efficacy. Neuropharmacology 2018; 143:186-204. [DOI: 10.1016/j.neuropharm.2018.09.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 08/30/2018] [Accepted: 09/16/2018] [Indexed: 01/01/2023]
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8
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Zeng X, Hu K, Chen L, Zhou L, Luo W, Li C, Zong W, Chen S, Gao Q, Zeng G, Jiang D, Li X, Zhou H, Ouyang DS. The Effects of Ginsenoside Compound K Against Epilepsy by Enhancing the γ-Aminobutyric Acid Signaling Pathway. Front Pharmacol 2018; 9:1020. [PMID: 30254585 PMCID: PMC6142013 DOI: 10.3389/fphar.2018.01020] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 08/22/2018] [Indexed: 01/15/2023] Open
Abstract
The imbalance between the GABA-mediated inhibition and the glutamate-mediated excitation is the primary pathological mechanism of epilepsy. GABAergic and glutamatergic neurotransmission have become the most important targets for controlling epilepsy. Ginsenoside compound K (GCK) is a main metabolic production of the ginsenoside Rb1, Rb2, and Rc in the intestinal microbiota. Previous studies show that GCK promoted the release of GABA from the hippocampal neurons and enhanced the activity of GABAA receptors. GCK is shown to reduce the expression of NMDAR and to attenuate the function of the NMDA receptors in the brain. The anti-seizure effects of GCK have not been reported so far. Therefore, this study aimed to investigate the effects of GCK on epilepsy and its potential mechanism. The rat model of seizure or status epilepticus (SE) was established with either Pentylenetetrazole or Lithium chloride-pilocarpine. The Racine's scale was used to evaluate seizure activity. The levels of the amino acid neurotransmitters were detected in the pilocarpine-induced epileptic rats. The expression levels of GABAARα1, NMDAR1, KCC2, and NKCC1 protein in the hippocampus were determined via western blot or immunohistochemistry after SE. We found that GCK had deceased seizure intensity and prolonged the latency of seizures. GCK increased the contents of GABA, while the contents of glutamate remained unchanged. GCK enhanced the expression of GABAARα1 in the brain and exhibited a tendency to decrease the expression of NMDAR1 protein in the hippocampus. The expression of KCC2 protein was elevated by the treatment of GCK after SE, while the expression of NKCC1 protein was reversely down-regulated. These findings suggested that GCK exerted anti-epileptic effects by promoting the hippocampal GABA release and enhancing the GABAAR-mediated inhibitory synaptic transmission.
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Affiliation(s)
- Xiangchang Zeng
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Kai Hu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Lulu Chen
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Luping Zhou
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Wei Luo
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Chaopeng Li
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Wenjing Zong
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Siyu Chen
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Qing Gao
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Guirong Zeng
- Hunan Key Laboratory of Pharmacodynamics and Safety Evaluation of New Drugs & Hunan Provincial Research Center for Safety Evaluation of Drugs, Changsha, China
| | - Dejian Jiang
- Hunan Key Laboratory of Pharmacodynamics and Safety Evaluation of New Drugs & Hunan Provincial Research Center for Safety Evaluation of Drugs, Changsha, China
| | - Xiaohui Li
- Department of Pharmacology, School of Pharmaceutical Sciences, Central South University, Changsha, China.,Hunan Key Laboratory for Bioanalysis of Complex Matrix Samples, Changsha Duxact Biotech Co., Ltd., Changsha, China
| | - Honghao Zhou
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China
| | - Dong-Sheng Ouyang
- Department of Clinical Pharmacology, Xiangya Hospital, Central South University, Changsha, China.,Institute of Clinical Pharmacology, Central South University, Changsha, China.,Hunan Key Laboratory for Bioanalysis of Complex Matrix Samples, Changsha Duxact Biotech Co., Ltd., Changsha, China
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Ben-Ari Y. NKCC1 Chloride Importer Antagonists Attenuate Many Neurological and Psychiatric Disorders. Trends Neurosci 2017; 40:536-554. [PMID: 28818303 DOI: 10.1016/j.tins.2017.07.001] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/03/2017] [Accepted: 07/10/2017] [Indexed: 12/23/2022]
Abstract
In physiological conditions, adult neurons have low intracellular Cl- [(Cl-)I] levels underlying the γ-aminobutyric acid (GABA)ergic inhibitory drive. In contrast, neurons have high (Cl-)I levels and excitatory GABA actions in a wide range of pathological conditions including spinal cord lesions, chronic pain, brain trauma, cerebrovascular infarcts, autism, Rett and Down syndrome, various types of epilepsies, and other genetic or environmental insults. The diuretic highly specific NKCC1 chloride importer antagonist bumetanide (PubChem CID: 2461) efficiently restores low (Cl-)I levels and attenuates many disorders in experimental conditions and in some clinical trials. Here, I review the mechanisms of action, therapeutic effects, promises, and pitfalls of bumetanide.
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Affiliation(s)
- Yehezkel Ben-Ari
- New INMED, Aix-Marseille University, Campus Scientifique de Luminy, Marseilles, France.
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10
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Activation of GABA A receptors controls mesiotemporal lobe epilepsy despite changes in chloride transporters expression: In vivo and in silico approach. Exp Neurol 2016; 284:11-28. [DOI: 10.1016/j.expneurol.2016.07.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 07/12/2016] [Accepted: 07/16/2016] [Indexed: 12/16/2022]
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11
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Eftekhari S, Mehrabi S, Karimzadeh F, Joghataei MT, Khaksarian M, Hadjighassem MR, Katebi M, Soleimani M. Brain Derived Neurotrophic Factor Modification of Epileptiform Burst Discharges in a Temporal Lobe Epilepsy Model. Basic Clin Neurosci 2016; 7:115-20. [PMID: 27303606 PMCID: PMC4892316 DOI: 10.15412/j.bcn.03070205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
INTRODUCTION Transforming Growth Factor-Beta 1 (TGF-β1) is a pleiotropic cytokine with potent anti-inflammatory property, which has been considered as an essential risk factor in the inflammatory process of Ischemic Stroke (IS), by involving in the pathophysiological progression of hypertension, atherosclerosis, and lipid metabolisms. -509C/T TGF-β1 gene polymorphism has been found to be associated with the risk of IS. The aim of this meta-analysis was to provide a relatively comprehensive account of the relation between -509C/T gene polymorphisms of TGF-β1 and susceptibility to IS. METHODS Male Wistar rats were divided into sham (receiving phosphate buffered saline within dorsal hippocampus), pilocarpine (epileptic model of TLE), single injection BDNF (epileptic rats which received single high dose of BDBF within dorsal hippocampus), and multiple injections BDNF (epileptic rats which received BDNF in days 10, 11, 12, and 13 after induction of TLE) groups. Their electrocorticogram was recorded and amplitude, frequency, and duration of spikes were evaluated. RESULTS Amplitude and frequency of epileptiform burst discharges were significantly decreased in animals treated with BDNF compared to pilocarpine group. CONCLUSION Our findings suggested that BDNF may modulate the epileptic activity in the animal model of TLE. In addition, it may have therapeutic effect for epilepsy. More studies are necessary to clarify the exact mechanisms of BDNF effects.
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Affiliation(s)
- Sanaz Eftekhari
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.; Department of Neuroscience, School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Soraya Mehrabi
- Shefa Neuroscience Center, Khatam-Alanbia Hospital, Tehran, Iran
| | - Fariba Karimzadeh
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad-Taghi Joghataei
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.; Department of Neuroscience, School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran.; Department of Anatomy, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mojtaba Khaksarian
- Department of Physiology, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Mahmoud Reza Hadjighassem
- Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran.; Brain and Spinal Cord Injury Research Centre, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Majid Katebi
- Department of Anatomy, School of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Mansooreh Soleimani
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.; Department of Anatomy, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Kaur A, Bali A, Singh N, Jaggi AS. Investigating the stress attenuating potential of furosemide in immobilization and electric foot-shock stress models in mice. Naunyn Schmiedebergs Arch Pharmacol 2015; 388:497-507. [PMID: 25604076 DOI: 10.1007/s00210-015-1084-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Accepted: 01/07/2015] [Indexed: 10/24/2022]
Abstract
The present study was designed to investigate the antistress effect of furosemide (sodium potassium chloride co-transporter inhibitor) in immobilization and foot-shock stress-induced behavioral alterations in the mice. Acute stress was induced in Swiss albino mice either by applying electric foot shocks of 0.6-mA intensity of 1-s duration with 30-s inter-shock interval for 1 h or immobilizing for 150 min. The acute stress-induced behavioral changes were assessed by using actophotometer, hole board, open-field, and social interaction tests. Biochemically, the corticosterone levels were estimated in the serum as a biomarker of hypothalamus-pituitary-adrenal (HPA) axis. Acute stress resulted in the development of behavioral alterations and elevation of the corticosterone levels. Intraperitoneal administration of furosemide (25 and 50 mg/kg) significantly attenuated immobilization and foot-shock stress-induced behavioral changes along with normalization of the corticosterone levels. It may be concluded that furosemide produces beneficial effects in reestablishing the behavioral and biochemical alterations in immobilization and foot-shock-induced acute stress in mice.
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Affiliation(s)
- Aalamjeet Kaur
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, 147002, India
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Vaughan DN, Jackson GD. The piriform cortex and human focal epilepsy. Front Neurol 2014; 5:259. [PMID: 25538678 PMCID: PMC4259123 DOI: 10.3389/fneur.2014.00259] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Accepted: 11/22/2014] [Indexed: 11/28/2022] Open
Abstract
It is surprising that the piriform cortex, when compared to the hippocampus, has been given relatively little significance in human epilepsy. Like the hippocampus, it has a phylogenetically preserved three-layered cortex that is vulnerable to excitotoxic injury, has broad connections to both limbic and cortical areas, and is highly epileptogenic – being critical to the kindling process. The well-known phenomenon of early olfactory auras in temporal lobe epilepsy highlights its clinical relevance in human beings. Perhaps because it is anatomically indistinct and difficult to approach surgically, as it clasps the middle cerebral artery, it has, until now, been understandably neglected. In this review, we emphasize how its unique anatomical and functional properties, as primary olfactory cortex, predispose it to involvement in focal epilepsy. From recent convergent findings in human neuroimaging, clinical epileptology, and experimental animal models, we make the case that the piriform cortex is likely to play a facilitating and amplifying role in human focal epileptogenesis, and may influence progression to epileptic intractability.
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Affiliation(s)
- David N Vaughan
- Florey Institute of Neuroscience and Mental Health , Heidelberg, VIC , Australia ; Department of Neurology, Austin Health , Heidelberg, VIC , Australia
| | - Graeme D Jackson
- Florey Institute of Neuroscience and Mental Health , Heidelberg, VIC , Australia ; Department of Neurology, Austin Health , Heidelberg, VIC , Australia ; Department of Medicine, University of Melbourne , Melbourne, VIC , Australia
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Akman O, Moshé SL, Galanopoulou AS. Sex-specific consequences of early life seizures. Neurobiol Dis 2014; 72 Pt B:153-66. [PMID: 24874547 DOI: 10.1016/j.nbd.2014.05.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 05/07/2014] [Accepted: 05/17/2014] [Indexed: 12/29/2022] Open
Abstract
Seizures are very common in the early periods of life and are often associated with poor neurologic outcome in humans. Animal studies have provided evidence that early life seizures may disrupt neuronal differentiation and connectivity, signaling pathways, and the function of various neuronal networks. There is growing experimental evidence that many signaling pathways, like GABAA receptor signaling, the cellular physiology and differentiation, or the functional maturation of certain brain regions, including those involved in seizure control, mature differently in males and females. However, most experimental studies of early life seizures have not directly investigated the importance of sex on the consequences of early life seizures. The sexual dimorphism of the developing brain raises the question that early seizures could have distinct effects in immature females and males that are subjected to seizures. We will first discuss the evidence for sex-specific features of the developing brain that could be involved in modifying the susceptibility and consequences of early life seizures. We will then review how sex-related biological factors could modify the age-specific consequences of induced seizures in the immature animals. These include signaling pathways (e.g., GABAA receptors), steroid hormones, growth factors. Overall, there are very few studies that have specifically addressed seizure outcomes in developing animals as a function of sex. The available literature indicates that a variety of outcomes (histopathological, behavioral, molecular, epileptogenesis) may be affected in a sex-, age-, region-specific manner after seizures during development. Obtaining a better understanding for the gender-related mechanisms underlying epileptogenesis and seizure comorbidities will be necessary to develop better gender and age appropriate therapies.
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Affiliation(s)
- Ozlem Akman
- Department of Physiology, Faculty of Medicine, Istanbul Bilim University, 34394 Istanbul, Turkey.
| | - Solomon L Moshé
- Saul R. Korey Department of Neurology, Laboratory of Developmental Epilepsy, Montefiore Epilepsy Management Center, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 10461, USA; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 10461, USA; Department of Pediatrics, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 10461, USA
| | - Aristea S Galanopoulou
- Saul R. Korey Department of Neurology, Laboratory of Developmental Epilepsy, Montefiore Epilepsy Management Center, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 10461, USA; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 10461, USA
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Töllner K, Brandt C, Töpfer M, Brunhofer G, Erker T, Gabriel M, Feit PW, Lindfors J, Kaila K, Löscher W. A novel prodrug-based strategy to increase effects of bumetanide in epilepsy. Ann Neurol 2014; 75:550-62. [PMID: 24615913 DOI: 10.1002/ana.24124] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 10/21/2013] [Accepted: 12/21/2013] [Indexed: 11/07/2022]
Abstract
OBJECTIVE There is considerable interest in using bumetanide, a chloride importer Na-K-Cl cotransporter antagonist, for treatment of neurological diseases, such as epilepsy or ischemic and traumatic brain injury, that may involve deranged cellular chloride homeostasis. However, bumetanide is heavily bound to plasma proteins (~98%) and highly ionized at physiological pH, so that it only poorly penetrates into the brain, and chronic treatment with bumetanide is compromised by its potent diuretic effect. METHODS To overcome these problems, we designed lipophilic and uncharged prodrugs of bumetanide that should penetrate the blood-brain barrier more easily than the parent drug and are converted into bumetanide in the brain. The feasibility of this strategy was evaluated in mice and rats. RESULTS Analysis of bumetanide levels in plasma and brain showed that administration of 2 ester prodrugs of bumetanide, the pivaloyloxymethyl (BUM1) and N,N-dimethylaminoethylester (BUM5), resulted in significantly higher brain levels of bumetanide than administration of the parent drug. BUM5, but not BUM1, was less diuretic than bumetanide, so that BUM5 was further evaluated in chronic models of epilepsy in mice and rats. In the pilocarpine model in mice, BUM5, but not bumetanide, counteracted the alteration in seizure threshold during the latent period. In the kindling model in rats, BUM5 was more efficacious than bumetanide in potentiating the anticonvulsant effect of phenobarbital. INTERPRETATION Our data demonstrate that the goal of designing bumetanide prodrugs that specifically target the brain is feasible and that such drugs may resolve the problems associated with using bumetanide for treatment of neurological disorders.
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Affiliation(s)
- Kathrin Töllner
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
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Galanopoulou AS, Moshé SL. Does epilepsy cause a reversion to immature function? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 813:195-209. [PMID: 25012378 DOI: 10.1007/978-94-017-8914-1_16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Seizures have variable effects on brain. Numerous studies have examined the consequences of seizures, in light of the way that these may alter the susceptibility of the brain to seizures, promote epileptogenesis, or functionally alter brain leading to seizure-related comorbidities. In many -but not all- situations, seizures shift brain function towards a more immature state, promoting the birth of newborn neurons, altering the dendritic structure and neuronal connectivity, or changing neurotransmitter signaling towards more immature patterns. These effects depend upon many factors, including the seizure type, age of seizure occurrence, sex, and brain region studied. Here we discuss some of these findings proposing that these seizure-induced immature features do not simply represent rejuvenation of the brain but rather a de-synchronization of the homeostatic mechanisms that were in place to maintain normal physiology, which may contribute to epileptogenesis or the cognitive comorbidities.
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Affiliation(s)
- Aristea S Galanopoulou
- Saul R. Korey Department of Neurology, Dominick P. Purpura Department of Neuroscience, The Laboratory of Developmental Epilepsy, Comprehensive Einstein/Montefiore Epilepsy Center, Albert Einstein College of Medicine, 1410 Pelham Parkway South, Kennedy Center Rm 306, Bronx, NY, 10461, USA,
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Töpfer M, Töllner K, Brandt C, Twele F, Bröer S, Löscher W. Consequences of inhibition of bumetanide metabolism in rodents on brain penetration and effects of bumetanide in chronic models of epilepsy. Eur J Neurosci 2013; 39:673-87. [PMID: 24251546 DOI: 10.1111/ejn.12424] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 09/24/2013] [Accepted: 10/14/2013] [Indexed: 11/28/2022]
Abstract
The diuretic bumetanide, which acts by blocking the Na-K-Cl cotransporter (NKCC), is widely used to inhibit neuronal NKCC1, particularly when NKCC1 expression is abnormally increased in brain diseases such as epilepsy. However, bumetanide poorly penetrates into the brain and, in rodents, is rapidly eliminated because of extensive oxidation of its N-butyl sidechain, reducing the translational value of rodent experiments. Inhibition of oxidation by piperonyl butoxide (PBO) has previously been reported to increase the half-life and diuretic activity of bumetanide in rats. Here we studied whether inhibition of bumetanide metabolism by PBO also increases brain levels of bumetanide in rats, and whether this alters pharmacodynamic effects in the kindling model of epilepsy. Furthermore, we studied the effects of PBO in mice. Mice eliminated bumetanide less rapidly than rats (elimination half-life 47 min vs. 13 min). Pretreatment with PBO increased the half-life in mice to average values (70 min) previously determined in humans, and markedly elevated brain levels of bumetanide. In rats, the increase in plasma and brain levels of bumetanide by PBO was less marked than in mice. PBO significantly increased the diuretic activity of bumetanide in rats and, less effectively, in mice. In epileptic mice, bumetanide (with PBO) did not suppress spontaneous seizures. In the rat kindling model, bumetanide (with or without PBO) did not exert anticonvulsant effects on fully kindled seizures, but dose-dependently altered kindling development. These data indicate that PBO offers a simple means to enhance the translational properties of rodent experiments with bumetanide, particularly when using mice.
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Affiliation(s)
- Manuel Töpfer
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Bünteweg 17, Hannover, D-30559, Germany; Center for Systems Neuroscience, Hannover, Germany
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Santos LEC, da Silveira GA, Costa VDC, Batista AG, Madureira AP, Rodrigues AM, Scorza CA, Amorim HA, Arida RM, Duarte MA, Scorza FA, Cavalheiro EA, de Almeida ACG. Alcohol abuse promotes changes in non-synaptic epileptiform activity with concomitant expression changes in cotransporters and glial cells. PLoS One 2013; 8:e78854. [PMID: 24236060 PMCID: PMC3827301 DOI: 10.1371/journal.pone.0078854] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 09/24/2013] [Indexed: 01/01/2023] Open
Abstract
Non-synaptic mechanisms are being considered the common factor of brain damage in status epilepticus and alcohol intoxication. The present work reports the influence of the chronic use of ethanol on epileptic processes sustained by non-synaptic mechanisms. Adult male Wistar rats administered with ethanol (1, 2 e 3 g/kg/d) during 28 days were compared with Control. Non-synaptic epileptiform activities (NEAs) were induced by means of the zero-calcium and high-potassium model using hippocampal slices. The observed involvement of the dentate gyrus (DG) on the neurodegeneration promoted by ethanol motivated the monitoring of the electrophysiological activity in this region. The DG regions were analyzed for the presence of NKCC1, KCC2, GFAP and CD11b immunoreactivity and cell density. The treated groups showed extracellular potential measured at the granular layer with increased DC shift and population spikes (PS), which was remarkable for the group E1. The latencies to the NEAs onset were more prominent also for the treated groups, being correlated with the neuronal loss. In line with these findings were the predispositions of the treated slices for neuronal edema after NEAs induction, suggesting that restrict inter-cell space counteracts the neuronal loss and subsists the hyper-synchronism. The significant increase of the expressions of NKCC1 and CD11b for the treated groups confirms the existence of conditions favorable to the observed edematous necrosis. The data suggest that the ethanol consumption promotes changes on the non-synaptic mechanisms modulating the NEAs. For the lower ethanol dosage the neurophysiological changes were more effective suggesting to be due to the less intense neurodegenertation.
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Affiliation(s)
- Luiz Eduardo Canton Santos
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei, São João del-Rei, Minas Gerais, Brasil
| | - Gilcélio Amaral da Silveira
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei, São João del-Rei, Minas Gerais, Brasil
| | - Victor Diego Cupertino Costa
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei, São João del-Rei, Minas Gerais, Brasil
| | - Aline Gisele Batista
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei, São João del-Rei, Minas Gerais, Brasil
| | - Ana Paula Madureira
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei, São João del-Rei, Minas Gerais, Brasil
| | - Antônio Márcio Rodrigues
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei, São João del-Rei, Minas Gerais, Brasil
| | - Carla Alessandra Scorza
- Disciplina de Neurologia Experimental, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, São Paulo, Brasil
| | - Henrique Alves Amorim
- Departamento de Ciência e Tecnologia, Universidade Federal de São Paulo, São José dos Campos, São Paulo, Brasil
| | - Ricardo Mário Arida
- Disciplina de Fisiologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, São Paulo, Brasil
| | - Mario Antônio Duarte
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei, São João del-Rei, Minas Gerais, Brasil
| | - Fúlvio Alexandre Scorza
- Disciplina de Neurologia Experimental, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, São Paulo, Brasil
| | - Esper Abrão Cavalheiro
- Disciplina de Neurologia Experimental, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, São Paulo, Brasil
| | - Antônio-Carlos Guimarães de Almeida
- Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, Universidade Federal de São João del-Rei, São João del-Rei, Minas Gerais, Brasil
- * E-mail:
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Ben-Ari Y, Khalilov I, Kahle KT, Cherubini E. The GABA excitatory/inhibitory shift in brain maturation and neurological disorders. Neuroscientist 2012; 18:467-86. [PMID: 22547529 DOI: 10.1177/1073858412438697] [Citation(s) in RCA: 407] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ionic currents and the network-driven patterns they generate differ in immature and adult neurons: The developing brain is not a "small adult brain." One of the most investigated examples is the developmentally regulated shift of actions of the transmitter GABA that inhibit adult neurons but excite immature ones because of an initially higher intracellular chloride concentration [Cl(-)](i), leading to depolarizing and often excitatory actions of GABA instead of hyperpolarizing and inhibitory actions. The levels of [Cl(-)](i) are also highly labile, being readily altered transiently or persistently by enhanced episodes of activity in relation to synaptic plasticity or a variety of pathological conditions, including seizures and brain insults. Among the plethora of channels, transporters, and other devices involved in controlling [Cl(-)](i), two have emerged as playing a particularly important role: the chloride importer NKCC1 and the chloride exporter KCC2. Here, the authors stress the importance of determining how [Cl(-)](i) is dynamically regulated and how this affects brain operation in health and disease. In a clinical perspective, agents that control [Cl(-)](i) and reinstate inhibitory actions of GABA open novel therapeutic perspectives in many neurological disorders, including infantile epilepsies, autism spectrum disorders, and other developmental disorders.
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A prolonged experimental febrile seizure results in motor map reorganization in adulthood. Neurobiol Dis 2011; 45:692-700. [PMID: 22044736 DOI: 10.1016/j.nbd.2011.10.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 09/22/2011] [Accepted: 10/16/2011] [Indexed: 01/24/2023] Open
Abstract
INTRODUCTION Clinical studies have suggested that children experiencing a febrile seizure (FS) before the age of 1year have persistent deficits, but it is unknown whether these seizures lead to permanent cortical reorganization and alterations in function. A FS on the background of increased genetic seizure susceptibility may also lead to negative long-term consequences. Alterations in neocortical motor map expression provide a measure of neocortical reorganization and have been reported in both adults with frontal lobe epilepsy and following seizure induction in experimental models. The objectives of the present study were to determine whether (1) an infantile FS leads to changes to motor map expression in adulthood; (2) long-term cortical reorganization is a function of the age at FS or genetic seizure susceptibility; and (3) different levels of GABA(A) or glutamate receptor subunits or cation-chloride-co-transporters (CCCs) at the time of FS correlate with alterations to motor map expression. MATERIALS AND METHODS FSs were induced in postnatal day 10 (P10) or P14 Long-Evans (LE) rats or in P14 seizure-prone FAST rats by the administration of the bacterial endotoxin lipopolysaccharide (LPS) and a subconvulsant dose of kainic acid. Ten weeks later intracortical microstimulation was performed to generate motor maps of forelimb movement representations. Sensorimotor neocortex samples were also dissected from naïve P10 FAST and P10 and P14 LE pups for western blotting with antibodies against various GABA(A), NMDA, and AMPA receptor subunits and for CCCs. RESULTS Adult FAST rats had larger motor maps with lower stimulation thresholds after a FS at P14, while adult LE rats had significantly lower map stimulation thresholds but similar sized maps after a FS at P10 compared to controls. There were no differences in neocortical motor map size or stimulation thresholds in adult LE rats after a FS at P14. Both P10 LE and P14 FAST rats had significantly lower levels of the GABA(A) receptor α1 subunit, higher levels of the α2 subunit, and a higher NKCC1/KCC2 ratio in the sensorimotor cortex compared with the P14 LE rat. In addition, the P14 FAST rats had lower levels of the GluR2 and NR2A receptor subunits in the sensorimotor cortex compared with the P14 LE rats. CONCLUSIONS A single infantile FS can have long-term effects on neocortical reorganization in younger individuals and those with underlying seizure susceptibility. These changes may be related to an increased level of excitability in the neocortex of younger or genetically seizure-prone rats, as suggested by immaturity of their GABAergic and CCC systems. Given the high incidence of FSs in children, it will be important to gain a better understanding of how age and genetic seizure predisposition may contribute to the long-term sequelae of these events.
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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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Shimizu-Okabe C, Tanaka M, Matsuda K, Mihara T, Okabe A, Sato K, Inoue Y, Fujiwara T, Yagi K, Fukuda A. KCC2 was downregulated in small neurons localized in epileptogenic human focal cortical dysplasia. Epilepsy Res 2011; 93:177-84. [PMID: 21256718 DOI: 10.1016/j.eplepsyres.2010.12.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Revised: 12/20/2010] [Accepted: 12/21/2010] [Indexed: 10/18/2022]
Abstract
Focal cortical dysplasia (FCD), which is characterized histologically by disorganized cortical lamination and large abnormal cells, is one of the major causes of intractable epilepsies. γ-aminobutyric acid (GABA)(A) receptor-mediated synchronous depolarizing potentials have been observed in FCD tissue. Since alterations in Cl(-) homeostasis might underlie these depolarizing actions of GABA, cation-Cl(-) cotransporters could play critical roles in the generation of these abnormal actions. We examined the expression patterns of NKCC1 and KCC2 by in situ hybridization histochemistry and immunohistochemistry in FCD tissue obtained by surgery from patients with intractable epilepsy. KCC2 mRNA and protein were expressed not only in non-dysplastic neurons in histologically normal portions located in the periphery of the excised cortex, but also in dysplastic cells in FCD tissue. The levels of KCC2 mRNA and protein were significantly decreased in the neurons around large abnormal neurons (giant neurons), but not in giant neurons, compared with non-dysplastic neurons. The neurons localized only around giant neurons significantly smaller than non-dysplastic neurons. However NKCC1 expression did not differ among these cell types. These results suggest that the intracellular Cl(-) concentration ([Cl(-)](i)) of small neurons might increase, so that depolarizing GABA actions could occur in the FCD tissue of epileptic foci.
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Affiliation(s)
- Chigusa Shimizu-Okabe
- Department of Physiology, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan.
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Wahab A, Albus K, Heinemann U. Age- and region-specific effects of anticonvulsants and bumetanide on 4-aminopyridine-induced seizure-like events in immature rat hippocampal-entorhinal cortex slices. Epilepsia 2010; 52:94-103. [PMID: 21083847 DOI: 10.1111/j.1528-1167.2010.02722.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
PURPOSE Seizure-like events (SLEs) induced by 4-aminopyridine in rat organotypic slices cultures, which are prepared early after birth, are resistant to standard antiepileptic drugs. In this study we tested the hypothesis that pharmacoresistance may be an intrinsic property of the immature brain. METHODS Frequently recurring SLEs presumably representing status epilepticus were induced by 4-aminopyridine in acute rat hippocampal-entorhinal cortex slices obtained from postnatal day 3-19 (P3-P19), and the effects of carbamazepine, phenytoin, valproic acid, and phenobarbital were examined. In addition, bumetanide was tested, which blocks the Na(+) -K(+) -2Cl(-) (NKCC1) cotransporter, and also acetazolamide, which blocks the carbonic anhydrase and thereby the accumulation of bicarbonate inside neurons. RESULTS The efficacy of all antiepileptic drugs in blocking SLEs was dependent on postnatal age, with low efficacy in P3-P5 slices. Antiepileptic drugs suppressed SLEs more readily in the medial entorhinal cortex (ECm) than in the CA3. In P3-P5 slices, valproic acid and phenobarbital increased both tonic and clonic seizure-like activities in the CA3, whereas phenytoin and carbamazepine blocked tonic-like but prolonged clonic-like activity. In P3-P5 slices, bumetanide often blocked SLEs in the CA3, but was not as effective in the ECm. Like with other antiepileptic drugs, the seizure-suppressing effects of acetazolamide increased with postnatal age. CONCLUSION We conclude that pharmacoresistance may be inherent to very immature tissue and suggest that expression of the NKCC1 cotransporter might contribute to pharmacoresistance.
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Affiliation(s)
- Abdul Wahab
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
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Nardou R, Ben-Ari Y, Khalilov I. Bumetanide, an NKCC1 antagonist, does not prevent formation of epileptogenic focus but blocks epileptic focus seizures in immature rat hippocampus. J Neurophysiol 2009; 101:2878-88. [PMID: 19297515 DOI: 10.1152/jn.90761.2008] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Excitatory GABA action induced by high [Cl(-)](i) is thought to contribute to seizure generation in neonatal neurons although the mechanism of this effect remains unclear. We report that bumetanide, a NKCC1 antagonist, reduces driving force of GABA-mediated currents (DF(GABA)) in neonatal hippocampal neurons and blocks the giant depolarizing potentials (GDPs), a spontaneous pattern of network activity. In the preparation composed of two intact interconnected hippocampi, bumetanide did not prevent generation of kainate-induced seizures, their propagation to the contralateral hippocampus, and formation of an epileptogenic mirror focus. However, in the isolated mirror focus, bumetanide effectively blocked spontaneous epileptiform activity transforming it to the GDP-like activity pattern. Bumetanide partially reduced DF(GABA) and therefore the excitatory action of GABA in epileptic neurons. Therefore bumetanide is a potent anticonvulsive agent although it cannot prevent formation of the epileptogenic mirror focus. We suggest that an additional mechanism other than NKCC1-mediated contributes to the persistent increase of DF(GABA) in epileptic neurons.
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Affiliation(s)
- Romain Nardou
- Institut de Neurobiologie de la Mediterranee, Institut National de la Santé et de la Recherche Médicale Unité 901, 13273 Marseille Cedex 09, France
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Li X, Zhou J, Chen Z, Chen S, Zhu F, Zhou L. Long-term expressional changes of Na+ -K+ -Cl- co-transporter 1 (NKCC1) and K+ -Cl- co-transporter 2 (KCC2) in CA1 region of hippocampus following lithium-pilocarpine induced status epilepticus (PISE). Brain Res 2008; 1221:141-6. [PMID: 18550034 DOI: 10.1016/j.brainres.2008.04.047] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Revised: 04/13/2008] [Accepted: 04/17/2008] [Indexed: 11/17/2022]
Abstract
NKCC1 and KCC2 are encoded by slc12 gene family and involved in the maintenance of intracellular chloride concentration which may be associated with epileptogenesis. In this study, we aimed to investigate the long-term expression profiles of NKCC1 and KCC2 in CA1 region in the mice model of lithium-pilocarpine induced status epilepticus (PISE) and their relationship with epileptogenesis. We found NKCC1 mRNA and proteins were up-regulated at 1 d, 14 d and 45 d after pilocarpine injection, while KCC2 was down-regulated. According to obtained results, there were some expressional changes of NKCC1 and KCC2. Deregulation of their expression may break the balance of intracellular and extracellular chloride concentration which contributes to the mechanism of hyperexcitability leading to seizures. Also it may provide new drug targets for development of new antiepileptic medicine.
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Affiliation(s)
- Xiubin Li
- Neurological Department of the 1st Affiliated Hospital of Sun Yat-sen University, GuangZhou, 510080, PR China
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Galanopoulou AS. GABA(A) receptors in normal development and seizures: friends or foes? Curr Neuropharmacol 2008; 6:1-20. [PMID: 19305785 PMCID: PMC2645547 DOI: 10.2174/157015908783769653] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Revised: 05/24/2007] [Accepted: 08/05/2007] [Indexed: 12/26/2022] Open
Abstract
GABA(A) receptors have an age-adapted function in the brain. During early development, they mediate excitatory effects resulting in activation of calcium sensitive signaling processes that are important for the differentiation of the brain. In more mature stages of development and in adults, GABA(A) receptors transmit inhibitory signals. The maturation of GABA(A) signaling follows sex-specific patterns, which appear to also be important for the sexual differentiation of the brain. The inhibitory effects of GABA(A) receptor activation have been widely exploited in the treatment of conditions where neuronal silencing is necessary. For instance, drugs that target GABA(A) receptors are the mainstay of treatment of seizures. Recent evidence suggests however that the physiology and function of GABA(A) receptors changes in the brain of a subject that has epilepsy or status epilepticus.This review will summarize the physiology of and the developmental factors regulating the signaling and function of GABA(A) receptors; how these may change in the brain that has experienced prior seizures; what are the implications for the age and sex specific treatment of seizures and status epilepticus. Finally, the implications of these changes for the treatment of certain forms of medically refractory epilepsies and status epilepticus will be discussed.
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Affiliation(s)
- Aristea S Galanopoulou
- Albert Einstein College of Medicine, Saul R Korey Department of Neurology & Dominick P Purpura, Department of Neuroscience, Bronx NY, USA.
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Muñoz A, DeFelipe J. Cell specificity of altered cation–chloride cotransporter expression and GABAergic innervation in the epileptic cerebral cortex. FUTURE NEUROLOGY 2007. [DOI: 10.2217/14796708.2.4.383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Evaluation of: Aronica E, Boer K, Redeker S et al.: Differential expression patterns of chloride transporters, Na+–K+–2Cl-cotransporter and K+–Cl- cotransporter (KCC2), in epilepsy-associated malformations of cortical development. Neuroscience 145(1), 185–196 (2007). The study by Aronica and colleagues used immunocytochemistry to investigate the changes in the expression and distribution of cation–chloride cotransporters in the cerebral cortex of epileptic patients when compared with age-matched controls. The aim was to determine whether or not the deregulation of cation–chloride cotransporter expression might contribute to the hyperexcitability that leads to seizures. The authors studied brain tissue from patients with medically intractable epilepsy associated with different types of malformations, including focal cortical dysplasia type IIB, hemimegalencephaly and ganglioglioma. They found weak neuronal and glial expression of the Na+–K+–2 Cl- cotransporter (NKCC1) in the normal control adult cortex, whereas NKCC1 was strongly expressed in different cell types from most patients, including large dysplastic neurons, balloon cells and astrocytes. In addition, the K+–Cl- cotransporter (KCC2) was reported to be diffusely distributed in the neuropil of control tissue, although more intense somatic KCC2 immunostaining was associated with large dysplastic neurons but not balloon cells in epileptic patients. The intense expression of NKCC1 in dysplastic neurons and the altered subcellular distribution of KCC2 were compared with the situation in the immature normal cortex. The authors concluded that altered expression of cation–chloride cotransporters in epileptic patients, in conjunction with malformations in cortical development, may contribute to epileptogenicity.
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Affiliation(s)
- Alberto Muñoz
- Universidad Complutense, Department of Cell Biology, 28040 Madrid, Spain, and, Instituto Cajal, Av. Dr Arce 37, 28002 Madrid, Spain
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Muñoz A, Méndez P, DeFelipe J, Alvarez-Leefmans FJ. Cation-chloride cotransporters and GABA-ergic innervation in the human epileptic hippocampus. Epilepsia 2007; 48:663-73. [PMID: 17319917 DOI: 10.1111/j.1528-1167.2007.00986.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Intracellular chloride concentration, [Cl(-)](i), determines the polarity of GABA(A)-induced neuronal Cl(-) currents. In neurons, [Cl(-)](i) is set by the activity of Na(+), K(+), 2Cl(-) cotransporters (NKCC) such as NKCC1, which physiologically accumulate Cl(-) in the cell, and Cl(-) extruding K(+), Cl(-) cotransporters like KCC2. Alterations in the balance of NKCC1 and KCC2 activity may determine the switch from hyperpolarizing to depolarizing effects of GABA, reported in the subiculum of epileptic patients with hippocampal sclerosis. We studied the expression of NKCC (putative NKCC1) and KCC2 in human normal temporal neocortex by Western blot analysis and in normal and epileptic regions of the subiculum and the hippocampus proper using immunocytochemistry. Western blot analysis revealed NKCC and KCC2 proteins in adult human neocortical membranes similar to those in rat neocortex. NKCC and KCC2 immunolabeling of pyramidal and nonpyramidal cells was found in normal and epileptic hippocampal formation. In the transition between the subiculum with sclerotic regions of CA1, known to exhibit epileptogenic activity, double immunolabeling of NKCC and KCC2 revealed that approximately 20% of the NKCC-immunoreactive neurons do not express KCC2. In these same areas some neurons were distinctly hyperinnervated by parvalbumin (PV) positive hypertrophic basket formations that innervated mostly neurons expressing NKCC (74%) and to a lesser extent NKCC-immunonegative neurons (26%). Hypertrophic basket formations also innervated KCC2-positive (76%) and -negative (24%) neurons. The data suggest that changes in the relative expression of NKCC1 and KCC2 in neurons having aberrant GABA-ergic hyperinnervation may contribute to epileptiform activity in the subicular regions adjacent to sclerotic areas of the hippocampus.
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Aronica E, Boer K, Redeker S, Spliet WGM, van Rijen PC, Troost D, Gorter JA. Differential expression patterns of chloride transporters, Na+-K+-2Cl--cotransporter and K+-Cl--cotransporter, in epilepsy-associated malformations of cortical development. Neuroscience 2007; 145:185-96. [PMID: 17207578 DOI: 10.1016/j.neuroscience.2006.11.041] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 10/24/2006] [Accepted: 11/18/2006] [Indexed: 10/23/2022]
Abstract
Malformations of cortical development are recognized causes of chronic medically intractable epilepsy. An increasing number of observations suggests an important role for cation-chloride co-transporters (CCTs) in controlling neuronal function. Deregulation of their expression may contribute to the mechanisms of hyperexcitability that lead to seizures. In the present study the expression and cell-specific distribution of Na+-K+-2Cl--cotransporter (NKCC1) and K+-Cl--cotransporter (KCC2) were studied immunocytochemically in different developmental lesions, including focal cortical dysplasia (FCD) type IIB (n=9), hemimegalencephaly (HMEG, n=6) and ganglioglioma (GG, n=9) from patients with medically intractable epilepsy and in age-matched controls. In normal control adult cortex, NKCC1 displayed low neuronal and glial expression levels. In contrast KCC2 showed strong and diffuse neuropil staining. Notable glial immunoreactivity (IR) was not found for KCC2. NKCC1 was highly expressed in the majority of FCD, HMEG and GG specimens. NKCC1 IR was observed in neurons of different size, including large dysplastic neurons, in balloon cells (in FCD and HMEG cases) and in glial cells with astrocytic morphology. The immunoreactivity pattern of KCC2 in FCD, HMEG and GG specimens was characterized by less neuropil staining and more intrasomatic IR compared with control. KCC2 IR was observed in neurons of different size, including large dysplastic neurons, but not in balloon cells or in glial cells with astrocytic morphology. Double-labeling experiments confirmed the differential cellular distribution of the two CCTs and their expression in GABA(A) receptor (alpha1 subunit)-positive dysplastic neurons. The cellular distribution of CCTs, with high expression of NKCC1 in dysplastic neurons and altered subcellular distribution of KCC2 resembles that of immature cortex and suggests a possible contribution of CCTs to the high epileptogenicity of malformations of cortical development.
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Affiliation(s)
- E Aronica
- Department of (Neuro) Pathology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
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Palma E, Amici M, Sobrero F, Spinelli G, Di Angelantonio S, Ragozzino D, Mascia A, Scoppetta C, Esposito V, Miledi R, Eusebi F. Anomalous levels of Cl- transporters in the hippocampal subiculum from temporal lobe epilepsy patients make GABA excitatory. Proc Natl Acad Sci U S A 2006; 103:8465-8. [PMID: 16709666 PMCID: PMC1482515 DOI: 10.1073/pnas.0602979103] [Citation(s) in RCA: 210] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The mRNA levels of NKCC1, an inwardly directed Na(+), K(+)-2Cl(-) cotransporter that facilitates the accumulation of intracellular Cl(-), and of KCC2, an outwardly directed K(+)-Cl(-) cotransporter that extrudes Cl(-), were studied in surgically resected brain specimens from drug-resistant temporal lobe (TL) epilepsy (TLE) patients. Quantitative RT-PCR analyses of the mRNAs extracted from the human TLE-associated brain regions revealed an up-regulation of NKCC1 mRNA and a down-regulation of KCC2 mRNA in the hippocampal subiculum, compared with the hippocampus proper or the TL neocortex, suggesting an abnormal transcription of Cl(-) transporters in the TLE subiculum. In parallel experiments, cell membranes isolated from the same TLE-associated brain regions were injected into Xenopus oocytes that rapidly incorporated human GABA(A) receptors into their surface membrane. The GABA currents elicited in oocytes injected with membranes from the subiculum had a more depolarized reversal potential (E(GABA)) compared with the hippocampus proper or the neocortex. The NKCC1 blocker bumetanide or a temperature decrease of 10 degrees C shifted the GABA-current E(GABA) more negative in oocytes injected with membranes from TLE hippocampal subiculum, matching the E(GABA) of TL neocortex-injected oocytes. We conclude that the anomalous expression of both Cl(-) transporters, NKCC1 and KCC2 [corrected] in TLE hippocampal subiculum probably causes altered Cl(-) transport in the "epileptic" neurons, as revealed in the microtransplanted Xenopus oocytes, and renders GABA aberrantly "exciting," a feature that may contribute to the precipitation of epileptic seizures.
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Affiliation(s)
- E. Palma
- *Istituto Pasteur, Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza Biologia e Medicina Molecolare, Università di Roma “La Sapienza,” Piazzale A. Moro 5, 00185 Rome, Italy
- Neuromed Istituto di Ricovero e Cura a Carattere Scientifico, Via Atinese 18, 86077 Pozzilli, Italy
- Istituto di Medicina e Scienza dello Sport, CONI, Via dei Campi Sportivi LG, 00197 Rome, Italy; and
- To whom correspondence may be addressed. E-mail:
or
| | - M. Amici
- *Istituto Pasteur, Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza Biologia e Medicina Molecolare, Università di Roma “La Sapienza,” Piazzale A. Moro 5, 00185 Rome, Italy
| | - F. Sobrero
- *Istituto Pasteur, Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza Biologia e Medicina Molecolare, Università di Roma “La Sapienza,” Piazzale A. Moro 5, 00185 Rome, Italy
| | - G. Spinelli
- *Istituto Pasteur, Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza Biologia e Medicina Molecolare, Università di Roma “La Sapienza,” Piazzale A. Moro 5, 00185 Rome, Italy
| | - S. Di Angelantonio
- *Istituto Pasteur, Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza Biologia e Medicina Molecolare, Università di Roma “La Sapienza,” Piazzale A. Moro 5, 00185 Rome, Italy
- Istituto di Medicina e Scienza dello Sport, CONI, Via dei Campi Sportivi LG, 00197 Rome, Italy; and
| | - D. Ragozzino
- *Istituto Pasteur, Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza Biologia e Medicina Molecolare, Università di Roma “La Sapienza,” Piazzale A. Moro 5, 00185 Rome, Italy
- Neuromed Istituto di Ricovero e Cura a Carattere Scientifico, Via Atinese 18, 86077 Pozzilli, Italy
| | - A. Mascia
- Neuromed Istituto di Ricovero e Cura a Carattere Scientifico, Via Atinese 18, 86077 Pozzilli, Italy
| | - C. Scoppetta
- Unità Operativa Neurologia 2, Ospedale S. Camillo, 00152 Rome, Italy
| | - V. Esposito
- Neuromed Istituto di Ricovero e Cura a Carattere Scientifico, Via Atinese 18, 86077 Pozzilli, Italy
| | - R. Miledi
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697-4550
- To whom correspondence may be addressed. E-mail:
or
| | - F. Eusebi
- *Istituto Pasteur, Fondazione Cenci Bolognetti and Dipartimento di Fisiologia Umana e Farmacologia, Centro di Eccellenza Biologia e Medicina Molecolare, Università di Roma “La Sapienza,” Piazzale A. Moro 5, 00185 Rome, Italy
- Istituto di Medicina e Scienza dello Sport, CONI, Via dei Campi Sportivi LG, 00197 Rome, Italy; and
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Kang TC, Kim DS, Kim JE, Kwak SE, Yoo KY, Hwang IK, Jung JY, Won MH, Kwon OS, Choi SY. Altered expression of K+ -Cl- cotransporters affects fast paired-pulse inhibition during GABA receptor activation in the gerbil hippocampus. Brain Res 2006; 1072:8-14. [PMID: 16412398 DOI: 10.1016/j.brainres.2005.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2004] [Revised: 10/18/2005] [Accepted: 12/04/2005] [Indexed: 11/16/2022]
Abstract
K+ -Cl- cotransporter (KCC) plays an important role in maintaining neuronal activity. However, the effect of seizure activity or pharmacological manipulation of GABAergic transmission on KCC expression remains to be clarified. Therefore, the present study was performed to investigate whether seizure activity or GABA receptor agonist treatment changes KCC expression in the gerbil hippocampus. Furthermore, the effect of blockade of KCC on inhibitory transmission in the dentate gyrus was identified following applications of GABA receptor agonists. The distribution of KCC immunoreactivity in the hippocampus was similarly detected between seizure-resistant (SR) and seizure-sensitive (SS) gerbils. Baclofen (a GABAB receptor agonist) treatment markedly increased KCC expression in the gerbil hippocampus. Baclofen treatment significantly reduced paired-pulse inhibition in the dentate gyrus. Furosemide (a KCC inhibitor) treatment amplified the effect of baclofen on paired-pulse responses. In contrast, muscimol (a GABAA receptor agonist) treatment reduced KCC expression. Enhanced paired-pulse inhibition by muscimol treatment was not affected by furosemide treatment. These findings suggest that seizure activity in the gerbil may not affect KCC expression in the hippocampus. In addition, altered KCC immunoreactivity induced by baclofen or muscimol may play an important role in maintaining or regulating inhibitory transmission during GABA receptor activation.
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Affiliation(s)
- Tae-Cheon Kang
- Department of Anatomy, College of Medicine, Hallym University, Chunchon, Kangwon-Do, 200-702, South Korea.
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Draguhn A, Hartmann K. GABAergic Synaptic Transmission. ADVANCES IN MOLECULAR AND CELL BIOLOGY 2006. [DOI: 10.1016/s1569-2558(06)38009-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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Jin X, Huguenard JR, Prince DA. Impaired Cl- extrusion in layer V pyramidal neurons of chronically injured epileptogenic neocortex. J Neurophysiol 2005; 93:2117-26. [PMID: 15774713 DOI: 10.1152/jn.00728.2004] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the mature brain, the K(+)/Cl- cotransporter KCC2 is important in maintaining low [Cl-]i, resulting in hyperpolarizing GABA responses. Decreases in KCC2 after neuronal injuries result in increases in [Cl-]i and enhanced neuronal excitability due to depolarizing GABA responses. We used the gramicidin perforated-patch technique to measure E(Cl) ( approximately E(GABA)) in layer V pyramidal neurons in slices of partially isolated sensorimotor cortex of adult rats to explore the potential functional consequence of KCC2 downregulation in chronically injured cortex. E(GABA) was measured by recording currents evoked with brief GABA puffs at various membrane potentials. There was no significant difference in E(Cl) between neurons in control and undercut animals (-71.2 +/- 2.6 and -71.8 +/- 2.8 mV, respectively). However, when loaded with Cl- by applying muscimol puffs at 0.2 Hz for 60 s, neurons in the undercut cortex had a significantly shorter time constant for the positive shift in E(Cl) during the Cl- loading phase (4.3 +/- 0.5 s for control and 2.2 +/- 0.4 s for undercut, P < 0.01). The positive shift in E(Cl) 3 s after the beginning of Cl- loading was also significantly larger in the undercut group than in the control, indicating that neurons in undercut cortex were less effective in maintaining low [Cl-]i during repetitive activation of GABA(A) receptors. Application of furosemide eliminated the difference between the control and undercut groups for both of these measures of [Cl-]i regulation. The results suggest an impairment in Cl- extrusion resulting from decreased KCC2 expression that may reduce the strength of GABAergic inhibition and contribute to epileptogenesis.
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Affiliation(s)
- Xiaoming Jin
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Room M016, Stanford, CA 94305-5122, USA
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Morales-Aza BM, Chillingworth NL, Payne JA, Donaldson LF. Inflammation alters cation chloride cotransporter expression in sensory neurons. Neurobiol Dis 2004; 17:62-9. [PMID: 15350966 DOI: 10.1016/j.nbd.2004.05.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Revised: 05/07/2004] [Accepted: 05/28/2004] [Indexed: 10/26/2022] Open
Abstract
Cation chloride cotransporters have been proposed to play a role in the modulation of neuronal responses to gamma-aminobutyric acid (GABA). In conditions of neuronal damage, where neuronal excitability is increased, the expression of the KCC2 transporter is decreased. This is also seen in spinal cord in models of neuropathic pain. We have investigated the expression of the Na-K-Cl, and K-Cl cotransporters NKCC1 and KCC2, in dorsal root ganglion (DRG) and spinal sensory neurons during arthritis, a condition in which neuronal excitability is also increased. NKCC1 was expressed in control DRG neurons, and its expression was decreased in arthritis. Both NKCC1 and KCC2 were expressed in sensory neurons in the spinal cord. In acute arthritis, both NKCC1 and KCC2 mRNA increased in superficial but not deep dorsal horn, and this was accompanied by an increase in protein expression. In chronic arthritis, NKCC1 expression remained raised, but KCC2 mRNA and protein expression returned to control levels. Altered KCC2 and NKCC1 expression in arthritis may contribute to the control of spinal cord excitability and may represent novel therapeutic targets in the treatment of inflammatory pain.
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Isomura Y, Sugimoto M, Fujiwara-Tsukamoto Y, Yamamoto-Muraki S, Yamada J, Fukuda A. Synaptically activated Cl- accumulation responsible for depolarizing GABAergic responses in mature hippocampal neurons. J Neurophysiol 2004; 90:2752-6. [PMID: 14534278 DOI: 10.1152/jn.00142.2003] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It is known that GABA, a major inhibitory transmitter in the CNS, acts as an excitatory (or depolarizing) transmitter transiently after intense GABAA receptor activation in adult brains. The depolarizing effect is considered to be dependent on two GABAA receptor-permeable anions, chloride (Cl-) and bicarbonate (HCO3-). However, little is known about their spatial and temporal profiles during the GABAergic depolarization in postsynaptic neurons. In the present study, we show that the amplitude of synaptically induced depolarizing response was correlated with intracellular Cl- accumulation in the soma of mature hippocampal CA1 pyramidal cells, by using whole cell patch-clamp recording and Cl- imaging technique with a Cl- indicator 6-methoxy-N-ethylquinolinium iodide (MEQ). The synaptically activated Cl- accumulation was mediated dominantly through GABAA receptors. Basket cells, a subclass of fast-spiking interneurons innervating the somatic portion of the pyramidal cells, actually fired at high frequency during the Cl- accumulation accompanying the depolarizing responses. These results suggest synaptically activated GABAA-mediated Cl- accumulation may play a critical role in generation of an excitatory GABAergic response in the mature pyramidal cells receiving intense synaptic inputs. This may be the first demonstration of microscopic visualization of intracellular Cl- accumulation during synaptic activation.
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Affiliation(s)
- Y Isomura
- Department of System Neuroscience, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Tokyo 183-8526, Japan.
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Okabe A, Yokokura M, Toyoda H, Shimizu-Okabe C, Ohno K, Sato K, Fukuda A. Changes in chloride homeostasis-regulating gene expressions in the rat hippocampus following amygdala kindling. Brain Res 2003; 990:221-6. [PMID: 14568348 DOI: 10.1016/s0006-8993(03)03528-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In a rat kindling model, we examined expression patterns of NKCC1, KCC1, KCC2, and CLC-2. In the dentate granule cell layer, there was an activity-dependent increase in NKCC1 mRNA but significant decreases in KCC1 and CLC-2 mRNAs. In addition, CLC-2 mRNA expression was markedly decreased in CA1 pyramidal layer. These results suggest that an increase in [Cl-]i and a resultant reduction in GABAergic inhibition may occur in hippocampus of epileptic rats.
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Affiliation(s)
- Akihito Okabe
- Department of Physiology, Hamamatsu University School of Medicine, Handayama 1-20-1, Hamamatsu, Shizuoka 431-3192, Japan.
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