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Meshkat S, Kwan ATH, Le GH, Wong S, Rhee TG, Ho R, Teopiz KM, Cao B, McIntyre RS. The role of KCNQ channel activators in management of major depressive disorder. J Affect Disord 2024; 359:364-372. [PMID: 38772507 DOI: 10.1016/j.jad.2024.05.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/12/2024] [Accepted: 05/15/2024] [Indexed: 05/23/2024]
Abstract
Depression, a complex disorder with significant treatment challenges, necessitates innovative therapeutic approaches to address its multifaceted nature and enhance treatment outcomes. The modulation of KCNQ potassium (K+) channels, pivotal regulators of neuronal excitability and neurotransmitter release, is a promising innovative therapeutic target in psychiatry. Widely expressed across various tissues, including the nervous and cardiovascular systems, KCNQ channels play a crucial role in modulating membrane potential and regulating neuronal activity. Recent preclinical evidence suggests that KCNQ channels, particularly KCNQ3, contribute to the regulation of neuronal excitability within the reward circuitry, offering a potential target for alleviating depressive symptoms, notably anhedonia. Studies using animal models demonstrate that interventions targeting KCNQ channels can restore dopaminergic firing balance and mitigate depressive symptoms. Human studies investigating the effects of KCNQ channel activators, such as ezogabine, have shown promising results in alleviating depressive symptoms and anhedonia. The aforementioned observations underscore the therapeutic potential of KCNQ channel modulation in depression management and highlight the need and justification for phase 2 and phase 3 dose-finding studies as well as studies prespecifying symptomatic targets in depression including anhedonia.
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Affiliation(s)
- Shakila Meshkat
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, Canada
| | - Angela T H Kwan
- Brain and Cognition Discovery Foundation, Toronto, Ontario, Canada; Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
| | - Gia Han Le
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, Canada; Brain and Cognition Discovery Foundation, Toronto, Ontario, Canada; Institute of Medical Science, University of Toronto, Toronto, Canada.
| | - Sabrina Wong
- Mood Disorders Psychopharmacology Unit, University Health Network, Toronto, Canada; Brain and Cognition Discovery Foundation, Toronto, Ontario, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada.
| | - Taeho Greg Rhee
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA; Department of Public Health Sciences, Farmington, CT, USA.
| | - Roger Ho
- Department of Psychological Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Institute for Health Innovation and Technology (iHealthtech), National University of Singapore, Singapore.
| | - Kayla M Teopiz
- Brain and Cognition Discovery Foundation, Toronto, Ontario, Canada.
| | - Bing Cao
- Key Laboratory of Cognition and Personality, Faculty of Psychology, Ministry of Education, Southwest University, Chongqing 400715, PR China.
| | - Roger S McIntyre
- Brain and Cognition Discovery Foundation, Toronto, Ontario, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada.
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2
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Urena ES, Diezel CC, Serna M, Hala'ufia G, Majuta L, Barber KR, Vanderah TW, Riegel AC. K v7 channel opener retigabine reduces self-administration of cocaine but not sucrose in rats. Addict Biol 2024; 29:e13428. [PMID: 39087789 PMCID: PMC11292668 DOI: 10.1111/adb.13428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 05/17/2024] [Accepted: 07/03/2024] [Indexed: 08/02/2024]
Abstract
The increasing rates of drug misuse highlight the urgency of identifying improved therapeutics for treatment. Most drug-seeking behaviours that can be modelled in rodents utilize the repeated intravenous self-administration (SA) of drugs. Recent studies examining the mesolimbic pathway suggest that Kv7/KCNQ channels may contribute to the transition from recreational to chronic drug use. However, to date, all such studies used noncontingent, experimenter-delivered drug model systems, and the extent to which this effect generalizes to rats trained to self-administer drugs is not known. Here, we tested the ability of retigabine (ezogabine), a Kv7 channel opener, to regulate instrumental behaviour in male Sprague Dawley rats. We first validated the ability of retigabine to target experimenter-delivered cocaine in a conditioned place preference (CPP) assay and found that retigabine reduced the acquisition of place preference. Next, we trained rats for cocaine-SA under a fixed-ratio or progressive-ratio reinforcement schedule and found that retigabine pretreatment attenuated the SA of low to moderate doses of cocaine. This was not observed in parallel experiments, with rats self-administering sucrose, a natural reward. Compared with sucrose-SA, cocaine-SA was associated with reductions in the expression of the Kv7.5 subunit in the nucleus accumbens, without alterations in Kv7.2 and Kv7.3. Therefore, these studies reveal a reward-specific reduction in SA behaviour and support the notion that Kv7 is a potential therapeutic target for human psychiatric diseases with dysfunctional reward circuitry.
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Affiliation(s)
- Esteban S. Urena
- Department of Pharmacology, College of MedicineUniversity of ArizonaTucsonArizonaUSA
| | - Cody C. Diezel
- Department of Pharmacology, College of MedicineUniversity of ArizonaTucsonArizonaUSA
| | - Mauricio Serna
- Department of Pharmacology, College of MedicineUniversity of ArizonaTucsonArizonaUSA
| | - Grace Hala'ufia
- Department of Pharmacology, College of MedicineUniversity of ArizonaTucsonArizonaUSA
| | - Lisa Majuta
- Department of Pharmacology, College of MedicineUniversity of ArizonaTucsonArizonaUSA
| | - Kara R. Barber
- Department of Pharmacology, College of MedicineUniversity of ArizonaTucsonArizonaUSA
| | - Todd W. Vanderah
- Department of Pharmacology, College of MedicineUniversity of ArizonaTucsonArizonaUSA
- Neuroscience Graduate Interdisciplinary ProgramUniversity of ArizonaTucsonArizonaUSA
- Comprehensive Pain and Addiction‐Center (CPA‐C)University of Arizona Health SciencesTucsonArizonaUSA
- The Center of Excellence in Addiction Studies (CEAS)University of ArizonaTucsonArizonaUSA
| | - Arthur C. Riegel
- Department of Pharmacology, College of MedicineUniversity of ArizonaTucsonArizonaUSA
- Neuroscience Graduate Interdisciplinary ProgramUniversity of ArizonaTucsonArizonaUSA
- Comprehensive Pain and Addiction‐Center (CPA‐C)University of Arizona Health SciencesTucsonArizonaUSA
- The Center of Excellence in Addiction Studies (CEAS)University of ArizonaTucsonArizonaUSA
- Department of Neuroscience, College of ScienceUniversity of ArizonaTucsonArizonaUSA
- James C. Wyant College of Optical SciencesUniversity of ArizonaTucsonArizonaUSA
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3
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Urena ES, Diezel CC, Serna M, Hala'ufia G, Majuta L, Barber KR, Vanderah TW, Riegel AC. K v 7 Channel Opener Retigabine Reduces Self-Administration of Cocaine but Not Sucrose in Rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.18.541208. [PMID: 37292619 PMCID: PMC10245780 DOI: 10.1101/2023.05.18.541208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The increasing rates of drug misuse highlight the urgency of identifying improved therapeutics for treatment. Most drug-seeking behaviors that can be modeled in rodents utilize the repeated intravenous self-administration (SA) of drugs. Recent studies examining the mesolimbic pathway suggest that K v 7/KCNQ channels may contribute in the transition from recreational to chronic drug use. However, to date, all such studies used noncontingent, experimenter-delivered drug model systems, and the extent to which this effect generalizes to rats trained to self-administer drug is not known. Here, we tested the ability of retigabine (ezogabine), a K v 7 channel opener, to regulate instrumental behavior in male Sprague Dawley rats. We first validated the ability of retigabine to target experimenter-delivered cocaine in a CPP assay and found that retigabine reduced the acquisition of place preference. Next, we trained rats for cocaine-SA under a fixed-ratio or progressive-ratio reinforcement schedule and found that retigabine-pretreatment attenuated the self-administration of low to moderate doses of cocaine. This was not observed in parallel experiments, with rats self-administering sucrose, a natural reward. Compared to sucrose-SA, cocaine-SA was associated with reductions in the expression of the K v 7.5 subunit in the nucleus accumbens, without alterations in K v 7.2 and K v 7.3. Therefore, these studies reveal a reward specific reduction in SA behavior considered relevant for the study of long-term compulsive-like behavior and supports the notion that K v 7 is a potential therapeutic target for human psychiatric diseases with dysfunctional reward circuitry.
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4
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Costi S, Han MH, Murrough JW. The Potential of KCNQ Potassium Channel Openers as Novel Antidepressants. CNS Drugs 2022; 36:207-216. [PMID: 35258812 DOI: 10.1007/s40263-021-00885-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/28/2021] [Indexed: 12/12/2022]
Abstract
Major depressive disorder (MDD) is a leading cause of disability worldwide and less than one-third of patients with MDD achieve stable remission of symptoms, despite currently available treatments. Although MDD represents a serious health problem, a complete understanding of the neurobiological mechanisms underlying this condition continues to be elusive. Accumulating evidence from preclinical and animal studies provides support for the antidepressant potential of modulators of KCNQ voltage-gated potassium (K+) channels. KCNQ K+ channels, through regulation of neuronal excitability and activity, contribute to neurophysiological mechanisms underlying stress resilience, and represent potential targets of drug discovery for depression. The present article focuses on the pharmacology and efficacy of KCNQ2/3 K+ channel openers as novel therapeutic agents for depressive disorders from initial studies conducted on animal models showing depressive-like behaviors to recent work in humans that examines the potential for KCNQ2/3 channel modulators as novel antidepressants. Data from preclinical work suggest that KCNQ-type K+ channels are an active mediator of stress resilience and KCNQ2/3 K+ channel openers show antidepressant efficacy. Similarly, evidence from clinical trials conducted in patients with MDD using the KCNQ2/3 channel opener ezogabine (retigabine) showed significant improvements in depressive symptoms and anhedonia. Overall, KCNQ channel openers appear a promising target for the development of novel therapeutics for the treatment of psychiatric disorders and specifically for MDD.
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Affiliation(s)
- Sara Costi
- Depression and Anxiety Center for Discovery and Treatment, Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1230, New York, NY, 10029, USA
| | - Ming-Hu Han
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Department of Mental Health and Public Health, Faculty of Life and Health Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - James W Murrough
- Depression and Anxiety Center for Discovery and Treatment, Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1230, New York, NY, 10029, USA. .,Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA. .,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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5
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Wrzosek A, Gałecka S, Żochowska M, Olszewska A, Kulawiak B. Alternative Targets for Modulators of Mitochondrial Potassium Channels. Molecules 2022; 27:299. [PMID: 35011530 PMCID: PMC8746388 DOI: 10.3390/molecules27010299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial potassium channels control potassium influx into the mitochondrial matrix and thus regulate mitochondrial membrane potential, volume, respiration, and synthesis of reactive oxygen species (ROS). It has been found that pharmacological activation of mitochondrial potassium channels during ischemia/reperfusion (I/R) injury activates cytoprotective mechanisms resulting in increased cell survival. In cancer cells, the inhibition of these channels leads to increased cell death. Therefore, mitochondrial potassium channels are intriguing targets for the development of new pharmacological strategies. In most cases, however, the substances that modulate the mitochondrial potassium channels have a few alternative targets in the cell. This may result in unexpected or unwanted effects induced by these compounds. In our review, we briefly present the various classes of mitochondrial potassium (mitoK) channels and describe the chemical compounds that modulate their activity. We also describe examples of the multidirectional activity of the activators and inhibitors of mitochondrial potassium channels.
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Affiliation(s)
- Antoni Wrzosek
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Shur Gałecka
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Monika Żochowska
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Anna Olszewska
- Department of Histology, Medical University of Gdansk, 1a Debinki, 80-211 Gdansk, Poland;
| | - Bogusz Kulawiak
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
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6
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Roy PK, Rajesh Y, Mandal M. Therapeutic targeting of membrane-associated proteins in central nervous system tumors. Exp Cell Res 2021; 406:112760. [PMID: 34339674 DOI: 10.1016/j.yexcr.2021.112760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/28/2021] [Accepted: 07/28/2021] [Indexed: 12/09/2022]
Abstract
The activity of the most complex system, the central nervous system (CNS) is profoundly regulated by a huge number of membrane-associated proteins (MAP). A minor change stimulates immense chemical changes and the elicited response is organized by MAP, which acts as a receptor of that chemical or channel enabling the flow of ions. Slight changes in the activity or expression of these MAPs lead to severe consequences such as cognitive disorders, memory loss, or cancer. CNS tumors are heterogeneous in nature and hard-to-treat due to random mutations in MAPs; like as overexpression of EGFRvIII/TGFβR/VEGFR, change in adhesion molecules α5β3 integrin/SEMA3A, imbalance in ion channel proteins, etc. Extensive research is under process for developing new therapeutic approaches using these proteins such as targeted cytotoxic radiotherapy, drug-delivery, and prodrug activation, blocking of receptors like GluA1, developing viral vector against cell surface receptor. The combinatorial approach of these strategies along with the conventional one might be more potential. Henceforth, our review focuses on in-depth analysis regarding MAPs aiming for a better understanding for developing an efficient therapeutic approach for targeting CNS tumors.
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Affiliation(s)
- Pritam Kumar Roy
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, India
| | - Yetirajam Rajesh
- Department of Human and Molecular Genetics, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Mahitosh Mandal
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, India.
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7
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Bayasgalan T, Stupniki S, Kovács A, Csemer A, Szentesi P, Pocsai K, Dionisio L, Spitzmaul G, Pál B. Alteration of Mesopontine Cholinergic Function by the Lack of KCNQ4 Subunit. Front Cell Neurosci 2021; 15:707789. [PMID: 34381336 PMCID: PMC8352570 DOI: 10.3389/fncel.2021.707789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 06/28/2021] [Indexed: 11/16/2022] Open
Abstract
The pedunculopontine nucleus (PPN), a structure known as a cholinergic member of the reticular activating system (RAS), is source and target of cholinergic neuromodulation and contributes to the regulation of the sleep–wakefulness cycle. The M-current is a voltage-gated potassium current modulated mainly by cholinergic signaling. KCNQ subunits ensemble into ion channels responsible for the M-current. In the central nervous system, KCNQ4 expression is restricted to certain brainstem structures such as the RAS nuclei. Here, we investigated the presence and functional significance of KCNQ4 in the PPN by behavioral studies and the gene and protein expressions and slice electrophysiology using a mouse model lacking KCNQ4 expression. We found that this mouse has alterations in the adaptation to changes in light–darkness cycles, representing the potential role of KCNQ4 in the regulation of the sleep–wakefulness cycle. As cholinergic neurons from the PPN participate in the regulation of this cycle, we investigated whether the cholinergic PPN might also possess functional KCNQ4 subunits. Although the M-current is an electrophysiological hallmark of cholinergic neurons, only a subpopulation of them had KCNQ4-dependent M-current. Interestingly, the absence of the KCNQ4 subunit altered the expression patterns of the other KCNQ subunits in the PPN. We also determined that, in wild-type animals, the cholinergic inputs of the PPN modulated the M-current, and these in turn can modulate the level of synchronization between neighboring PPN neurons. Taken together, the KCNQ4 subunit is present in a subpopulation of PPN cholinergic neurons, and it may contribute to the regulation of the sleep–wakefulness cycle.
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Affiliation(s)
- T Bayasgalan
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - S Stupniki
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional Del Sur (UNS), Bahía Blanca, Argentina.,Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - A Kovács
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - A Csemer
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - P Szentesi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - K Pocsai
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - L Dionisio
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional Del Sur (UNS), Bahía Blanca, Argentina.,Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - G Spitzmaul
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional Del Sur (UNS), Bahía Blanca, Argentina.,Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - B Pál
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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McCoy MT, Jayanthi S, Cadet JL. Potassium Channels and Their Potential Roles in Substance Use Disorders. Int J Mol Sci 2021; 22:1249. [PMID: 33513859 PMCID: PMC7865894 DOI: 10.3390/ijms22031249] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 01/12/2023] Open
Abstract
Substance use disorders (SUDs) are ubiquitous throughout the world. However, much remains to be done to develop pharmacotherapies that are very efficacious because the focus has been mostly on using dopaminergic agents or opioid agonists. Herein we discuss the potential of using potassium channel activators in SUD treatment because evidence has accumulated to support a role of these channels in the effects of rewarding drugs. Potassium channels regulate neuronal action potential via effects on threshold, burst firing, and firing frequency. They are located in brain regions identified as important for the behavioral responses to rewarding drugs. In addition, their expression profiles are influenced by administration of rewarding substances. Genetic studies have also implicated variants in genes that encode potassium channels. Importantly, administration of potassium agonists have been shown to reduce alcohol intake and to augment the behavioral effects of opioid drugs. Potassium channel expression is also increased in animals with reduced intake of methamphetamine. Together, these results support the idea of further investing in studies that focus on elucidating the role of potassium channels as targets for therapeutic interventions against SUDs.
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Affiliation(s)
| | | | - Jean Lud Cadet
- Molecular Neuropsychiatry Research Branch, NIDA Intramural Research Program, Baltimore, MD 21224, USA; (M.T.M.); (S.J.)
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9
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Zwierzyńska E, Krupa-Burtnik A, Pietrzak B. Beneficial effect of retigabine on memory in rats receiving ethanol. Pharmacol Rep 2021; 73:480-489. [PMID: 33385172 PMCID: PMC7994244 DOI: 10.1007/s43440-020-00205-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/14/2020] [Accepted: 11/29/2020] [Indexed: 11/25/2022]
Abstract
Background Retigabine belongs to the novel generation of antiepileptic drugs but its complex mechanism of action causes that the drug might be effective in other diseases, for instance, alcohol dependence. It is known that ethanol abuse impaired the function of brain structures associated with memory and learning such as the hippocampus. In our previous study, retigabine reduced hippocampal changes induced by ethanol in the EEG rhythms in rabbits. This study is focused on the impact of retigabine on memory processes in male rats receiving alcohol. Methods Memory was evaluated in various experimental models: Morris water maze, Contextual, and Cued Fear Conditioning tests. Retigabine was administered for 3 weeks directly to the stomach via oral gavage at a dose of 10 mg/kg. Rats received also 20% ethanol (5 g/kg/day in two doses) via oral gavage for 3 weeks and had free access to 5% ethanol in the afternoon and at night. Morris water maze was performed after 1 and 3 weeks of ethanol administration and after 1 week from the discontinuation of ethanol administration. Contextual and Cued Fear Conditioning tests were carried out after 24 h and 72 h of alcohol discontinuation. Results The drug significantly decreased ethanol-induced memory disturbances during alcohol administration as well as slightly improved learning processes after the discontinuation of ethanol administration. Conclusions This beneficial effect of retigabine-ethanol interaction on memory may be a relevant element of the drug’s impact on the development of addiction.
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Affiliation(s)
- Ewa Zwierzyńska
- Department of Pharmacodynamics, Medical University of Lodz, Muszyńskiego 1, 90-151, Łódź, Poland.
| | - Agata Krupa-Burtnik
- Department of Pharmacodynamics, Medical University of Lodz, Muszyńskiego 1, 90-151, Łódź, Poland
| | - Bogusława Pietrzak
- Department of Pharmacodynamics, Medical University of Lodz, Muszyńskiego 1, 90-151, Łódź, Poland
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10
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Baculis BC, Zhang J, Chung HJ. The Role of K v7 Channels in Neural Plasticity and Behavior. Front Physiol 2020; 11:568667. [PMID: 33071824 PMCID: PMC7530275 DOI: 10.3389/fphys.2020.568667] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/28/2020] [Indexed: 12/12/2022] Open
Abstract
Activity-dependent persistent changes in neuronal intrinsic excitability and synaptic strength are widely thought to underlie learning and memory. Voltage-gated KCNQ/Kv7 potassium channels have been of great interest as the potential targets for memory disorders due to the beneficial effects of their antagonists in cognition. Importantly, de novo dominant mutations in their neuronal subunits KCNQ2/Kv7.2 and KCNQ3/Kv7.3 are associated with epilepsy and neurodevelopmental disorder characterized by developmental delay and intellectual disability. The role of Kv7 channels in neuronal excitability and epilepsy has been extensively studied. However, their functional significance in neural plasticity, learning, and memory remains largely unknown. Here, we review recent studies that support the emerging roles of Kv7 channels in intrinsic and synaptic plasticity, and their contributions to cognition and behavior.
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Affiliation(s)
- Brian C Baculis
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Jiaren Zhang
- Department of Molecular Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Hee Jung Chung
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, United States.,Department of Molecular Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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11
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Berteau S, Bullock D. Simulations reveal how M-currents and memory-based inputs from CA3 enable single neuron mismatch detection for EC3 inputs to the CA1 subfield of hippocampus. J Neurophysiol 2020; 124:544-556. [PMID: 32609564 DOI: 10.1152/jn.00238.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Significant evidence has accumulated to support the hypothesis that hippocampal region CA1 operates as an associative mismatch detector (e.g., Hasselmo ME, Schnell E, Barkai E. J Neurosci 15: 5249-5262, 1995; Duncan K, Curtis C, Davachi L. J Neurosci 29: 131-139, 2009; Kumaran D, Maguire EA. J Neurosci 27: 8517-8524, 2007; Lisman JE, Grace AA. Neuron 46: 703-713, 2005; Lisman JE, Otmakhova NA. Hippocampus 11: 551-568 2001; Lörincz A, Buzsáki G. Ann N Y Acad Sci 911: 83-111, 2000; Meeter M, Murre JMJ, Talamini LM. Hippocampus 14: 722-741, 2004; Schiffer AM, Ahlheim C, Wurm MF, Schubotz RI. PLoS One 7: e36445, 2012; Vinogradova OS. Hippocampus 11: 578-598 2001). CA1 compares predictive synaptic signals from CA3 with synaptic signals from EC3, which reflect actual sensory inputs. The new CA1 pyramidal model presented here shows that the distal-proximal segregation of synaptic inputs from EC3 versus CA3, along with other biophysical features, enable such pyramids to serve as comparators that switch output encoding from a brief burst, for a match, to prolonged tonic spiking, for a mismatch. By including often-overlooked features of CA1 pyramidal neurons, this new model allows simulation of pharmacological effects that can eliminate either the match (phasic mode) response or the mismatch (tonic mode) response. These simulations reveal that dysfunctions can arise from either too much or too little ACh stimulation of the muscarinic receptors that control KCNQ channels. Additionally, a dysfunction caused by administration of an N-methyl-d-aspartate antagonist could be rescued by simultaneous administration of a KCNQ channel agonist, such as retigabine.NEW & NOTEWORTHY Hippocampal region CA1 operates as an associative mismatch detector, comparing predictive signals from CA3 with signals from EC3 reflecting sensory inputs. This new CA1 pyramidal model shows that biophysical features enable these comparators to switch output between brief bursts for matches and tonic spiking for mismatches. This suggests that cognitive learning models (e.g., predictive coding) may require much less match/mismatch circuitry than commonly assumed. Additional simulations illuminate deficits seen in psychiatric disorders and drug-induced states.
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Affiliation(s)
- Stefan Berteau
- Cognitive & Neural Systems Program, Boston University, Boston, Massachusetts
| | - Daniel Bullock
- Cognitive & Neural Systems Program, Boston University, Boston, Massachusetts
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12
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Vigil FA, Carver CM, Shapiro MS. Pharmacological Manipulation of K v 7 Channels as a New Therapeutic Tool for Multiple Brain Disorders. Front Physiol 2020; 11:688. [PMID: 32636759 PMCID: PMC7317068 DOI: 10.3389/fphys.2020.00688] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 05/27/2020] [Indexed: 12/12/2022] Open
Abstract
K v 7 ("M-type," KCNQ) K+ currents, play dominant roles in controlling neuronal excitability. They act as a "brake" against hyperexcitable states in the central and peripheral nervous systems. Pharmacological augmentation of M current has been developed for controlling epileptic seizures, although current pharmacological tools are uneven in practical usefulness. Lately, however, M-current "opener" compounds have been suggested to be efficacious in preventing brain damage after multiple types of insults/diseases, such as stroke, traumatic brain injury, drug addiction and mood disorders. In this review, we will discuss what is known to date on these efforts and identify gaps in our knowledge regarding the link between M current and therapeutic potential for these disorders. We will outline the preclinical experiments that are yet to be performed to demonstrate the likelihood of success of this approach in human trials. Finally, we also address multiple pharmacological tools available to manipulate different K v 7 subunits and the relevant evidence for translational application in the clinical use for disorders of the central nervous system and multiple types of brain insults. We feel there to be great potential for manipulation of K v 7 channels as a novel therapeutic mode of intervention in the clinic, and that the paucity of existing therapies obligates us to perform further research, so that patients can soon benefit from such therapeutic approaches.
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Affiliation(s)
- Fabio A Vigil
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Chase M Carver
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, United States
| | - Mark S Shapiro
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, United States
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13
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Kim EC, Patel J, Zhang J, Soh H, Rhodes JS, Tzingounis AV, Chung HJ. Heterozygous loss of epilepsy gene KCNQ2 alters social, repetitive and exploratory behaviors. GENES BRAIN AND BEHAVIOR 2019; 19:e12599. [PMID: 31283873 PMCID: PMC7050516 DOI: 10.1111/gbb.12599] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/28/2019] [Accepted: 07/06/2019] [Indexed: 12/28/2022]
Abstract
KCNQ/Kv7 channels conduct voltage‐dependent outward potassium currents that potently decrease neuronal excitability. Heterozygous inherited mutations in their principle subunits Kv7.2/KCNQ2 and Kv7.3/KCNQ3 cause benign familial neonatal epilepsy whereas patients with de novo heterozygous Kv7.2 mutations are associated with early‐onset epileptic encephalopathy and neurodevelopmental disorders characterized by intellectual disability, developmental delay and autism. However, the role of Kv7.2‐containing Kv7 channels in behaviors especially autism‐associated behaviors has not been described. Because pathogenic Kv7.2 mutations in patients are typically heterozygous loss‐of‐function mutations, we investigated the contributions of Kv7.2 to exploratory, social, repetitive and compulsive‐like behaviors by behavioral phenotyping of both male and female KCNQ2+/− mice that were heterozygous null for the KCNQ2 gene. Compared with their wild‐type littermates, male and female KCNQ2+/− mice displayed increased locomotor activity in their home cage during the light phase but not the dark phase and showed no difference in motor coordination, suggesting hyperactivity during the inactive light phase. In the dark phase, KCNQ2+/− group showed enhanced exploratory behaviors, and repetitive grooming but decreased sociability with sex differences in the degree of these behaviors. While male KCNQ2+/− mice displayed enhanced compulsive‐like behavior and social dominance, female KCNQ2+/− mice did not. In addition to elevated seizure susceptibility, our findings together indicate that heterozygous loss of Kv7.2 induces behavioral abnormalities including autism‐associated behaviors such as reduced sociability and enhanced repetitive behaviors. Therefore, our study is the first to provide a tangible link between loss‐of‐function Kv7.2 mutations and the behavioral comorbidities of Kv7.2‐associated epilepsy.
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Affiliation(s)
- Eung Chang Kim
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Jaimin Patel
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Jiaren Zhang
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Heun Soh
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut
| | - Justin S Rhodes
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois.,Department of Psychology, University of Illinois at Urbana-Champaign, Urbana, Illinois.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | | | - Hee Jung Chung
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois
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14
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Abstract
The highly structurally similar drugs flupirtine and retigabine have been regarded as safe and effective for many years but lately they turned out to exert intolerable side effects. While the twin molecules share the mode of action, both stabilize the open state of voltage-gated potassium channels, the form and severity of adverse effects is different. The analgesic flupirtine caused drug-induced liver injury in rare but fatal cases, whereas prolonged use of the antiepileptic retigabine led to blue tissue discoloration. Because the adverse effects seem unrelated to the mode of action, it is likely, that both drugs that occupied important therapeutic niches, could be replaced. Reasons for the clinically relevant toxicity will be clarified and future substitutes for these drugs presented in this review.
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15
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McGuier NS, Rinker JA, Cannady R, Fulmer DB, Jones SR, Hoffman M, Mulholland PJ. Identification and validation of midbrain Kcnq4 regulation of heavy alcohol consumption in rodents. Neuropharmacology 2018; 138:10-19. [PMID: 29775679 DOI: 10.1016/j.neuropharm.2018.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/27/2018] [Accepted: 05/14/2018] [Indexed: 12/12/2022]
Abstract
Currently available pharmacotherapies for treating alcohol use disorder (AUD) suffer from deleterious side effects and are not efficacious in diverse populations. Clinical and preclinical studies provide evidence that the Kcnq family of genes that encode KV7 channels influence alcohol intake and dependence. KV7 channels are a class of slowly activating voltage-dependent K+ channels that regulate neuronal excitability. Studies indicate that the KV7 channel positive modulator retigabine can decrease dopaminergic neuron firing, alter dopamine (DA) release, and reduce alcohol intake in heavy drinking rodents. Given the critical nature of ventral tegmental area (VTA) DA to the addiction process and predominant expression of Kcnq4 in DA neurons, we investigated the role of midbrain Kcnq genes and KV7 channels in the VTA of genetically diverse mice and long-term heavy drinking rats, respectively. Integrative bioinformatics analysis identified negative correlations between midbrain Kcnq4 expression and alcohol intake and seeking behaviors. Kcnq4 expression levels were also correlated with dopaminergic-related phenotypes in BXD strains, and Kcnq4 was present in support intervals for alcohol sensitivity and alcohol withdrawal severity QTLs in rodents. Pharmacological validation studies revealed that VTA KV7 channels regulate excessive alcohol intake in rats with a high-drinking phenotype. Administration of a novel and selective KV7.2/4 channel positive modulator also reduced alcohol drinking in rats. Together, these findings indicate that midbrain Kcnq4 expression regulates alcohol-related behaviors in genetically diverse mice and provide evidence that KV7.4 channels are a critical mediator of excessive alcohol drinking.
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Affiliation(s)
- Natalie S McGuier
- Medical University of South Carolina, Department of Neuroscience, 67 President Street, Charleston, SC, 29425, United States
| | - Jennifer A Rinker
- Medical University of South Carolina, Department of Neuroscience, 67 President Street, Charleston, SC, 29425, United States; Medical University of South Carolina, Department of Psychiatry & Behavioral Sciences, 67 President Street, Charleston, SC, 29425, United States
| | - Reginald Cannady
- Medical University of South Carolina, Department of Neuroscience, 67 President Street, Charleston, SC, 29425, United States
| | - Diana B Fulmer
- Medical University of South Carolina, Department of Neuroscience, 67 President Street, Charleston, SC, 29425, United States
| | - Sara R Jones
- Wake Forest School of Medicine, Department of Physiology and Pharmacology, 1 Medical Center Boulevard, Winston Salem, NC, 27157, United States
| | - Michaela Hoffman
- Medical University of South Carolina, Department of Psychiatry & Behavioral Sciences, 67 President Street, Charleston, SC, 29425, United States
| | - Patrick J Mulholland
- Medical University of South Carolina, Department of Neuroscience, 67 President Street, Charleston, SC, 29425, United States; Medical University of South Carolina, Department of Psychiatry & Behavioral Sciences, 67 President Street, Charleston, SC, 29425, United States.
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16
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Abstract
The efficacy of KCNQ2/3 channel agonists against drug reward has not been defined despite their ability to reduce locomotor-stimulant and dopamine-activating effects of psychostimulants. We tested the hypothesis that flupirtine (FLU) (2.5, 10, 20 mg/kg), a KCNQ2/3 agonist, reduces cocaine (15 mg/kg) conditioned place preference. FLU (20 mg/kg), injected concurrently with cocaine during conditioning, reduced the development of cocaine conditioned place preference. FLU (20 mg/kg) also reduced cocaine locomotor activation without affecting baseline activity. The disruption of cocaine place preference by FLU suggests that KCNQ2/3 channels influence cocaine's rewarding effects.
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17
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Nielsen J, Fejgin K, Sotty F, Nielsen V, Mørk A, Christoffersen CT, Yavich L, Lauridsen JB, Clausen D, Larsen PH, Egebjerg J, Werge TM, Kallunki P, Christensen KV, Didriksen M. A mouse model of the schizophrenia-associated 1q21.1 microdeletion syndrome exhibits altered mesolimbic dopamine transmission. Transl Psychiatry 2017; 7:1261. [PMID: 29187755 PMCID: PMC5802512 DOI: 10.1038/s41398-017-0011-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 07/19/2017] [Accepted: 08/04/2017] [Indexed: 01/07/2023] Open
Abstract
1q21.1 hemizygous microdeletion is a copy number variant leading to eightfold increased risk of schizophrenia. In order to investigate biological alterations induced by this microdeletion, we generated a novel mouse model (Df(h1q21)/+) and characterized it in a broad test battery focusing on schizophrenia-related assays. Df(h1q21)/+ mice displayed increased hyperactivity in response to amphetamine challenge and increased sensitivity to the disruptive effects of amphetamine and phencyclidine hydrochloride (PCP) on prepulse inhibition. Probing of the direct dopamine (DA) pathway using the DA D1 receptor agonist SKF-81297 revealed no differences in induced locomotor activity compared to wild-type mice, but Df(h1q21)/+ mice showed increased sensitivity to the DA D2 receptor agonist quinpirole and the D1/D2 agonist apomorphine. Electrophysiological characterization of DA neuron firing in the ventral tegmental area revealed more spontaneously active DA neurons and increased firing variability in Df(h1q21)/+ mice, and decreased feedback reduction of DA neuron firing in response to amphetamine. In a range of other assays, Df(h1q21)/+ mice showed no difference from wild-type mice: gross brain morphology and basic functions such as reflexes, ASR, thermal pain sensitivity, and motor performance were unaltered. Similarly, anxiety related measures, baseline prepulse inhibition, and seizure threshold were unaltered. In addition to the central nervous system-related phenotypes, Df(h1q21)/+ mice exhibited reduced head-to tail length, which is reminiscent of the short stature reported in humans with 1q21.1 deletion. With aspects of both construct and face validity, the Df(h1q21)/+ model may be used to gain insight into schizophrenia-relevant alterations in dopaminergic transmission.
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MESH Headings
- Abnormalities, Multiple/metabolism
- Abnormalities, Multiple/pathology
- Abnormalities, Multiple/physiopathology
- Amphetamine/pharmacology
- Animals
- Apomorphine/pharmacology
- Behavior, Animal/drug effects
- Benzazepines/pharmacology
- Chromosome Deletion
- Chromosomes, Human, Pair 1/metabolism
- Disease Models, Animal
- Dopamine Agonists/administration & dosage
- Dopamine Agonists/pharmacology
- Dopamine Uptake Inhibitors/administration & dosage
- Dopamine Uptake Inhibitors/pharmacology
- Dopaminergic Neurons/drug effects
- Dopaminergic Neurons/metabolism
- Excitatory Amino Acid Antagonists/administration & dosage
- Excitatory Amino Acid Antagonists/pharmacology
- Megalencephaly/metabolism
- Megalencephaly/pathology
- Megalencephaly/physiopathology
- Mice
- Mice, Inbred C57BL
- Nucleus Accumbens/drug effects
- Nucleus Accumbens/metabolism
- Phencyclidine/pharmacology
- Phenotype
- Prepulse Inhibition/drug effects
- Quinpirole/pharmacology
- Receptors, Dopamine/drug effects
- Receptors, Dopamine/metabolism
- Schizophrenia/metabolism
- Schizophrenia/pathology
- Schizophrenia/physiopathology
- Ventral Tegmental Area/drug effects
- Ventral Tegmental Area/metabolism
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Affiliation(s)
- Jacob Nielsen
- Division of Synaptic Transmission, H. Lundbeck A/S, Valby, Denmark.
| | - Kim Fejgin
- Division of Synaptic Transmission, H. Lundbeck A/S, Valby, Denmark
| | - Florence Sotty
- Division of Neurodegeneration, H. Lundbeck A/S, Valby, Denmark
| | - Vibeke Nielsen
- Division of Synaptic Transmission, H. Lundbeck A/S, Valby, Denmark
| | - Arne Mørk
- Division of Synaptic Transmission, H. Lundbeck A/S, Valby, Denmark
| | | | - Leonid Yavich
- Invilog Research Ltd and School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Jes B Lauridsen
- Division of Synaptic Transmission, H. Lundbeck A/S, Valby, Denmark
| | - Dorte Clausen
- Division of Synaptic Transmission, H. Lundbeck A/S, Valby, Denmark
| | - Peter H Larsen
- Division of Synaptic Transmission, H. Lundbeck A/S, Valby, Denmark
| | - Jan Egebjerg
- Division of Neurodegeneration, H. Lundbeck A/S, Valby, Denmark
| | - Thomas M Werge
- Institute of Biological Psychiatry, Mental Health Services of Copenhagen, University of Copenhagen & The Lundbeck Foundation's IPSYCH Initiative, Copenhagen, Denmark
| | - Pekka Kallunki
- Division of Neurodegeneration, H. Lundbeck A/S, Valby, Denmark
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18
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Abstract
Major depressive disorder (MDD) is a chronic and potentially life threatening illness that carries a staggering global burden. Characterized by depressed mood, MDD is often difficult to diagnose and treat owing to heterogeneity of syndrome and complex etiology. Contemporary antidepressant treatments are based on improved monoamine-based formulations from serendipitous discoveries made > 60 years ago. Novel antidepressant treatments are necessary, as roughly half of patients using available antidepressants do not see long-term remission of depressive symptoms. Current development of treatment options focuses on generating efficacious antidepressants, identifying depression-related neural substrates, and better understanding the pathophysiological mechanisms of depression. Recent insight into the brain's mesocorticolimbic circuitry from animal models of depression underscores the importance of ionic mechanisms in neuronal homeostasis and dysregulation, and substantial evidence highlights a potential role for ion channels in mediating depression-related excitability changes. In particular, hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are essential regulators of neuronal excitability. In this review, we describe seminal research on HCN channels in the prefrontal cortex and hippocampus in stress and depression-related behaviors, and highlight substantial evidence within the ventral tegmental area supporting the development of novel therapeutics targeting HCN channels in MDD. We argue that methods targeting the activity of reward-related brain areas have significant potential as superior treatments for depression.
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Affiliation(s)
- Stacy M Ku
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Ming-Hu Han
- Department of Pharmacological Sciences and Institute for Systems Biomedicine, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
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19
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Feeney EJ, Groman SM, Taylor JR, Corlett PR. Explaining Delusions: Reducing Uncertainty Through Basic and Computational Neuroscience. Schizophr Bull 2017; 43:263-272. [PMID: 28177090 PMCID: PMC5605246 DOI: 10.1093/schbul/sbw194] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Delusions, the fixed false beliefs characteristic of psychotic illness, have long defied understanding despite their response to pharmacological treatments (e.g., D2 receptor antagonists). However, it can be challenging to discern what makes beliefs delusional compared with other unusual or erroneous beliefs. We suggest mapping the putative biology to clinical phenomenology with a cognitive psychology of belief, culminating in a teleological approach to beliefs and brain function supported by animal and computational models. We argue that organisms strive to minimize uncertainty about their future states by forming and maintaining a set of beliefs (about the organism and the world) that are robust, but flexible. If uncertainty is generated endogenously, beliefs begin to depart from consensual reality and can manifest into delusions. Central to this scheme is the notion that formal associative learning theory can provide an explanation for the development and persistence of delusions. Beliefs, in animals and humans, may be associations between representations (e.g., of cause and effect) that are formed by minimizing uncertainty via new learning and attentional allocation. Animal research has equipped us with a deep mechanistic basis of these processes, which is now being applied to delusions. This work offers the exciting possibility of completing revolutions of translation, from the bedside to the bench and back again. The more we learn about animal beliefs, the more we may be able to apply to human beliefs and their aberrations, enabling a deeper mechanistic understanding.
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Affiliation(s)
- Erin J Feeney
- Department of Psychiatry, Ribicoff Research Facilities, Connecticut Mental Health Center, Yale University, Park Street, New Haven, CT, USA
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA
| | - Stephanie M Groman
- Department of Psychiatry, Ribicoff Research Facilities, Connecticut Mental Health Center, Yale University, Park Street, New Haven, CT, USA
| | - Jane R Taylor
- Department of Psychiatry, Ribicoff Research Facilities, Connecticut Mental Health Center, Yale University, Park Street, New Haven, CT, USA
| | - Philip R Corlett
- Department of Psychiatry, Ribicoff Research Facilities, Connecticut Mental Health Center, Yale University, Park Street, New Haven, CT, USA
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20
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McGuier NS, Griffin WC, Gass JT, Padula AE, Chesler EJ, Mulholland PJ. Kv7 channels in the nucleus accumbens are altered by chronic drinking and are targets for reducing alcohol consumption. Addict Biol 2016; 21:1097-1112. [PMID: 26104325 DOI: 10.1111/adb.12279] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Alcohol use disorders (AUDs) are a major public health issue and produce enormous societal and economic burdens. Current Food and Drug Administration (FDA)-approved pharmacotherapies for treating AUDs suffer from deleterious side effects and are only effective in a subset of individuals. It is therefore essential to find improved medications for the management of AUDs. Emerging evidence suggests that anticonvulsants are a promising class of drugs for treating individuals with AUDs. In these studies, we used integrative functional genomics to demonstrate that genes that encode Kv7 channels (i.e. Kcnq2/3) are related to alcohol (ethanol) consumption, preference and acceptance in rodents. We then tested the ability of the FDA-approved anticonvulsant retigabine, a Kv7 channel opener, to reduce voluntary ethanol consumption of Wistar rats in a two-bottle choice intermittent alcohol access paradigm. Systemic administration and microinjections of retigabine into the nucleus accumbens significantly reduced alcohol drinking, and retigabine was more effective at reducing intake in high- versus low-drinking populations of Wistar rats. Prolonged voluntary drinking increased the sensitivity to the proconvulsant effects of pharmacological blockade of Kv7 channels and altered surface trafficking and SUMOylation patterns of Kv7.2 channels in the nucleus accumbens. These data implicate Kcnq2/3 in the regulation of ethanol drinking and demonstrate that long-term drinking produces neuroadaptations in Kv7 channels. In addition, these results have identified retigabine as a potential pharmacotherapy for treating AUDs and Kv7 channels as a novel therapeutic target for reducing heavy drinking.
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Affiliation(s)
- Natalie S. McGuier
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
| | - William C. Griffin
- Department of Psychiatry and Behavioral Sciences; Medical University of South Carolina; Charleston SC USA
| | - Justin T. Gass
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
| | - Audrey E. Padula
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
| | | | - Patrick J. Mulholland
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
- Department of Psychiatry and Behavioral Sciences; Medical University of South Carolina; Charleston SC USA
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21
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Hansen HH, Weikop P, Mikkelsen MD, Rode F, Mikkelsen JD. The pan-Kv7 (KCNQ) Channel Opener Retigabine Inhibits Striatal Excitability by Direct Action on Striatal Neurons In Vivo. Basic Clin Pharmacol Toxicol 2016; 120:46-51. [PMID: 27377794 DOI: 10.1111/bcpt.12636] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 06/30/2016] [Indexed: 11/29/2022]
Abstract
Central Kv7 (KCNQ) channels are voltage-dependent potassium channels composed of different combinations of four Kv7 subunits, being differently expressed in the brain. Notably, striatal dopaminergic neurotransmission is strongly suppressed by systemic administration of the pan-Kv7 channel opener retigabine. The effect of retigabine likely involves the inhibition of the activity in mesencephalic dopaminergic neurons projecting to the striatum, but whether Kv7 channels expressed in the striatum may also play a role is not resolved. We therefore assessed the effect of intrastriatal retigabine administration on striatal neuronal excitability in the rat determined by c-Fos immunoreactivity, a marker of neuronal activation. When retigabine was applied locally in the striatum, this resulted in a marked reduction in the number of c-Fos-positive neurons after a strong excitatory striatal stimulus induced by acute systemic haloperidol administration in the rat. The relative mRNA levels of Kv7 subunits in the rat striatum were found to be Kv7.2 = Kv7.3 = Kv7.5 > >Kv7.4. These data suggest that intrastriatal Kv7 channels play a direct role in regulating striatal excitability in vivo.
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Affiliation(s)
- Henrik H Hansen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Denmark.,NeuroSearch A/S, Ballerup, Denmark
| | - Pia Weikop
- Neuropsychiatric Laboratory, Copenhagen University Hospital, Rigshospitalet, Denmark
| | | | | | - Jens D Mikkelsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Denmark.,NeuroSearch A/S, Ballerup, Denmark
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22
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Heal DJ, Goddard S, Brammer RJ, Hutson PH, Vickers SP. Lisdexamfetamine reduces the compulsive and perseverative behaviour of binge-eating rats in a novel food reward/punished responding conflict model. J Psychopharmacol 2016; 30:662-75. [PMID: 27170676 DOI: 10.1177/0269881116647506] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Compulsive and perseverative behaviour in binge-eating, female, Wistar rats was investigated in a novel food reward/punished responding conflict model. Rats were trained to perform the conditioned avoidance response task. When proficient, the paradigm was altered to a food-associated conflict test by placing a chocolate-filled jar (empty jar for controls) in one compartment of the shuttle box. Entry into the compartment with the jar triggered the conditioning stimulus after a variable interval, and foot-shock 10 seconds later if the rat did not leave. Residence in the 'safe' compartment with no jar did not initiate trials or foot-shocks. By frequently entering the chocolate-paired compartment, binge-eating rats completed their 10 trials more quickly than non-binge controls. Binge-eating rats spent a greater percentage of the session in the chocolate-paired compartment, received foot-shocks more frequently, and tolerated foot-shocks for longer periods; all consistent with compulsive and perseverative behaviour. The d-amphetamine prodrug, lisdexamfetamine, has recently received US approval for the treatment of moderate to severe binge-eating disorder in adults. Lisdexamfetamine (0.8 mg/kg po [d-amphetamine base]) decreased chocolate consumption by binge-eating rats by 55% and markedly reduced compulsive and perseverative responding in the model. These findings complement clinical results showing lisdexamfetamine reduced compulsiveness scores in subjects with binge-eating disorder.
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23
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Friedman AK, Juarez B, Ku SM, Zhang H, Calizo RC, Walsh JJ, Chaudhury D, Zhang S, Hawkins A, Dietz DM, Murrough JW, Ribadeneira M, Wong EH, Neve RL, Han MH. KCNQ channel openers reverse depressive symptoms via an active resilience mechanism. Nat Commun 2016; 7:11671. [PMID: 27216573 PMCID: PMC4890180 DOI: 10.1038/ncomms11671] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 04/18/2016] [Indexed: 02/01/2023] Open
Abstract
Less than half of patients suffering from major depressive disorder, a leading cause of disability worldwide, achieve remission with current antidepressants, making it imperative to develop more effective treatment. A new therapeutic direction is emerging from the increased understanding of natural resilience as an active stress-coping process. It is known that potassium (K(+)) channels in the ventral tegmental area (VTA) are an active mediator of resilience. However, no druggable targets have been identified to potentiate active resilience mechanisms. In the chronic social defeat stress model of depression, we report that KCNQ-type K(+) channel openers, including FDA-approved drug retigabine (ezogabine), show antidepressant efficacy. We demonstrate that overexpression of KCNQ channels in the VTA dopaminergic neurons and either local infusion or systemic administration of retigabine normalized neuronal hyperactivity and depressive behaviours. These findings identify KCNQ as a target for conceptually novel antidepressants that function through the potentiation of active resilience mechanisms.
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Affiliation(s)
- Allyson K Friedman
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Department of Biological Sciences, Hunter College, Biology and Biochemistry PhD Program, Graduate Center, The City University of New York, New York, New York 10065, USA
| | - Barbara Juarez
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Stacy M Ku
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Hongxing Zhang
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Rhodora C Calizo
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Jessica J Walsh
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Dipesh Chaudhury
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Song Zhang
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Angel Hawkins
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - David M Dietz
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - James W Murrough
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Maria Ribadeneira
- CNS Pain Innovative Medicine Unit, AstraZeneca Pharmaceuticals, Wilmington, Delaware 19850, USA
| | - Erik H Wong
- CNS Pain Innovative Medicine Unit, AstraZeneca Pharmaceuticals, Wilmington, Delaware 19850, USA
| | - Rachael L Neve
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Ming-Hu Han
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
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Peltola MA, Kuja-Panula J, Liuhanen J, Võikar V, Piepponen P, Hiekkalinna T, Taira T, Lauri SE, Suvisaari J, Kulesskaya N, Paunio T, Rauvala H. AMIGO-Kv2.1 Potassium Channel Complex Is Associated With Schizophrenia-Related Phenotypes. Schizophr Bull 2016; 42:191-201. [PMID: 26240432 PMCID: PMC4681558 DOI: 10.1093/schbul/sbv105] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The enormous variability in electrical properties of neurons is largely affected by a multitude of potassium channel subunits. Kv2.1 is a widely expressed voltage-dependent potassium channel and an important regulator of neuronal excitability. The Kv2.1 auxiliary subunit AMIGO constitutes an integral part of the Kv2.1 channel complex in brain and regulates the activity of the channel. AMIGO and Kv2.1 localize to the distinct somatodendritic clusters at the neuronal plasma membrane. Here we have created and characterized a mouse line lacking the AMIGO gene. Absence of AMIGO clearly reduced the amount of the Kv2.1 channel protein in mouse brain and altered the electrophysiological properties of neurons. These changes were accompanied by behavioral and pharmacological abnormalities reminiscent of those identified in schizophrenia. Concomitantly, we have detected an association of a rare, population-specific polymorphism of KV2.1 (KCNB1) with human schizophrenia in a genetic isolate enriched with schizophrenia. Our study demonstrates the involvement of AMIGO-Kv2.1 channel complex in schizophrenia-related behavioral domains in mice and identifies KV2.1 (KCNB1) as a strong susceptibility gene for schizophrenia spectrum disorders in humans.
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Affiliation(s)
- Marjaana A. Peltola
- Neuroscience Center, University of Helsinki, Helsinki, Finland;,*To whom correspondence should be addressed; Neuroscience Center, PO Box 56 (Viikinkaari 4), FI-00014 University of Helsinki, Helsinki, Finland; tel: +358-2941-57649, fax: +358-2941-57620, e-mail:
| | | | - Johanna Liuhanen
- Public Health Genomics Unit, National Institute for Health and Welfare, Helsinki, Finland
| | - Vootele Võikar
- Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Petteri Piepponen
- Division of Pharmacology and Toxicology, University of Helsinki, Helsinki, Finland
| | - Tero Hiekkalinna
- Public Health Genomics Unit, National Institute for Health and Welfare, Helsinki, Finland;,Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - Tomi Taira
- Neuroscience Center, University of Helsinki, Helsinki, Finland;,Department of Biosciences, University of Helsinki, Helsinki, Finland;,Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | - Sari E. Lauri
- Neuroscience Center, University of Helsinki, Helsinki, Finland;,Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Jaana Suvisaari
- Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland
| | | | - Tiina Paunio
- Public Health Genomics Unit, National Institute for Health and Welfare, Helsinki, Finland;,Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland;,Department of Psychiatry, Institute of Clinical Medicine, University of Helsinki, Helsinki, Finland
| | - Heikki Rauvala
- Neuroscience Center, University of Helsinki, Helsinki, Finland
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25
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Klinger F, Bajric M, Salzer I, Dorostkar MM, Khan D, Pollak DD, Kubista H, Boehm S, Koenig X. δ Subunit-containing GABAA receptors are preferred targets for the centrally acting analgesic flupirtine. Br J Pharmacol 2015. [PMID: 26211808 PMCID: PMC4621994 DOI: 10.1111/bph.13262] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Background and Purpose The Kv7 channel activator flupirtine is a clinical analgesic characterized as ‘selective neuronal potassium channel opener’. Flupirtine was found to exert comparable actions at GABAA receptors and Kv7 channels in neurons of pain pathways, but not in hippocampus. Experimental Approach Expression patterns of GABAA receptors were explored in immunoblots of rat dorsal root ganglia, dorsal horns and hippocampi using antibodies for 10 different subunits. Effects of flupirtine on recombinant and native GABAA receptors were investigated in patch clamp experiments and compared with the actions on Kv7 channels. Key Results Immunoblots pointed towards α2, α3, β3 and γ2 subunits as targets, but in all γ2‐containing receptors the effects of flupirtine were alike: leftward shift of GABA concentration‐response curves and diminished maximal amplitudes. After replacement of γ2S by δ, flupirtine increased maximal amplitudes. Currents through α1β2δ receptors were more enhanced than those through Kv7 channels. In hippocampal neurons, flupirtine prolonged inhibitory postsynaptic currents, left miniature inhibitory postsynaptic currents (mIPSCs) unaltered and increased bicuculline‐sensitive tonic currents; penicillin abolished mIPSCs, but not tonic currents; concentration‐response curves for GABA‐induced currents were shifted to the left by flupirtine without changes in maximal amplitudes; in the presence of penicillin, maximal amplitudes were increased; GABA‐induced currents in the presence of penicillin were more sensitive towards flupirtine than K+ currents. In dorsal horn neurons, currents evoked by the δ‐preferring agonist THIP (gaboxadol) were more sensitive towards flupirtine than K+ currents. Conclusions and Implications Flupirtine prefers δ‐containing GABAA receptors over γ‐containing ones and over Kv7 channels.
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Affiliation(s)
- Felicia Klinger
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Mirnes Bajric
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Isabella Salzer
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Mario M Dorostkar
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Deeba Khan
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Daniela D Pollak
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Helmut Kubista
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Stefan Boehm
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
| | - Xaver Koenig
- Department of Neurophysiology and Neuropharmacology, Centre for Physiology and Pharmacology, Medical University of Vienna, Spitalgasse 23, Vienna, 1090, Austria
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26
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Redrobe JP, Rasmussen LK, Christoffersen CT, Bundgaard C, Jørgensen M. Characterisation of Lu AF33241: A novel, brain-penetrant, dual inhibitor of phosphodiesterase (PDE) 2A and PDE10A. Eur J Pharmacol 2015; 761:79-85. [DOI: 10.1016/j.ejphar.2015.04.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 04/01/2015] [Accepted: 04/16/2015] [Indexed: 11/26/2022]
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Treven M, Koenig X, Assadpour E, Gantumur E, Meyer C, Hilber K, Boehm S, Kubista H. The anticonvulsant retigabine is a subtype selective modulator of GABAA receptors. Epilepsia 2015; 56:647-57. [PMID: 25779225 PMCID: PMC4949651 DOI: 10.1111/epi.12950] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2015] [Indexed: 01/17/2023]
Abstract
OBJECTIVE Within its range of therapeutic plasma concentrations, the anticonvulsant retigabine (ezogabine) is believed to selectively act on Kv7 channels. Here, the contribution of specific γ-aminobutyric acid (GABA)A receptor subtypes to the antiseizure effects of retigabine was investigated. METHODS Using patch-clamp recordings, seizure-like activity, tonic currents, and GABA-induced currents in hippocampal neurons were tested for their sensitivity toward retigabine, as were recombinant GABAA receptors expressed in tsA 201 cells. RESULTS Retigabine reduced seizure-like activity elicited by low Mg(2+) in a concentration-dependent manner with half maximal inhibition at 1 μm. Seizure-like activity triggered by blocking either Kv7 channels or GABAA receptors was equally reduced by retigabine, but when these channels/receptors were blocked simultaneously, the inhibition was lost. Retigabine (10 μm) enhanced bicuculline-sensitive tonic currents in hippocampal neurons, but failed to affect GABA-evoked currents. However, when receptors involved in phasic GABAergic inhibition were blocked by penicillin, retigabine did enhance GABA-evoked currents. In tsA 201 cells expressing various combinations of GABAA receptor subunits, 10 μm retigabine enhanced currents through α1β2δ, α4β2δ, α4β3δ, and α6β2δ receptors, but left currents through α1β2γ2S, α4β3γ2S, α5β3γ2S, and α6β2γ2S receptors unaltered. With αβ receptors, retigabine diminished currents through α1β2 and α4β3, but increased currents through α6β2 receptors. The enhancement of currents through α1β2δ receptors by retigabine was concentration dependent and became significant at 1 μm. SIGNIFICANCE These results demonstrate that retigabine is a subtype selective modulator of GABAA receptors with preference for extrasynaptic δ-containing receptors; this property may contribute to its broad antiepileptic effectiveness and explain its lack of effect on absence seizures.
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Affiliation(s)
- Marco Treven
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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Zwierzyńska E, Krupa A, Pietrzak B. A pharmaco-EEG study of the interaction between ethanol and retigabine in rabbits. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2015; 41:153-60. [DOI: 10.3109/00952990.2014.987349] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Ewa Zwierzyńska
- Department of Pharmacodynamics, Medical University of Łódź, Łódź, Poland
| | - Agata Krupa
- Department of Pharmacodynamics, Medical University of Łódź, Łódź, Poland
| | - Bogusława Pietrzak
- Department of Pharmacodynamics, Medical University of Łódź, Łódź, Poland
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29
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Redrobe JP, Jørgensen M, Christoffersen CT, Montezinho LP, Bastlund JF, Carnerup M, Bundgaard C, Lerdrup L, Plath N. In vitro and in vivo characterisation of Lu AF64280, a novel, brain penetrant phosphodiesterase (PDE) 2A inhibitor: potential relevance to cognitive deficits in schizophrenia. Psychopharmacology (Berl) 2014; 231:3151-67. [PMID: 24577516 DOI: 10.1007/s00213-014-3492-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 02/05/2014] [Indexed: 12/25/2022]
Abstract
Here, we present the pharmacological characterisation of Lu AF64280, a novel, selective, brain penetrant phosphodiesterase (PDE) 2A inhibitor, in in vitro/in vivo assays indicative of PDE2A inhibition, and in vivo models/assays relevant to cognitive processing or antipsychotic-like activity. The in vitro selectivity of Lu AF64280 was determined against a panel of PDE enzymes and 3',5'-cyclic guanosine monophosphate (cGMP) levels in the hippocampus were determined using in vivo microdialysis. Lu AF64280 potently inhibited hPDE2A (Ki = 20 nM), 50-fold above moderate inhibition of both hPDE9A (Ki = 1,000 nM) and hPDE10A (Ki = 1,800 nM), and displayed a >250-fold selectivity over all other full-length human recombinant PDE family members (Ki above 5,000 nM). Lu AF64280 (20 mg/kg) significantly increased cGMP levels in the hippocampus (p < 0.01 versus vehicle-treated mice), attenuated sub-chronic phencyclidine-induced deficits in novel object exploration in rats (10 mg/kg, p < 0.001 versus vehicle-treated), blocked early postnatal phencyclidine-induced deficits in the intradimensional/extradimensional shift task in rats (1 and 10 mg/kg, p < 0.001 versus vehicle-treated) and attenuated spontaneous P20-N40 auditory gating deficits in DBA/2 mice (20 mg/kg, p < 0.05 versus vehicle-treated). In contrast, Lu AF64280 failed to attenuate phencyclidine-induced hyperactivity in mice, and was devoid of antipsychotic-like activity in the conditioned avoidance response paradigm in rats, at any dose tested. Lu AF64280 represents a novel tool compound for selective PDE2A inhibition that substantiates a critical role of this enzyme in cognitive processes under normal and pathological conditions.
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Affiliation(s)
- John P Redrobe
- Neuroscience Research DK, H. Lundbeck A/S, Ottiliavej 9, Valby, 2500, Copenhagen, Denmark
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30
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Blom SM, Rottländer M, Kehler J, Bundgaard C, Schmitt N, Jensen HS. From pan-reactive KV7 channel opener to subtype selective opener/inhibitor by addition of a methyl group. PLoS One 2014; 9:e100209. [PMID: 24956197 PMCID: PMC4067310 DOI: 10.1371/journal.pone.0100209] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/22/2014] [Indexed: 01/24/2023] Open
Abstract
The voltage-gated potassium channels of the KV7 family (KV7.1–5) play important roles in controlling neuronal excitability and are therefore attractive targets for treatment of CNS disorders linked to hyperexcitability. One of the main challenges in developing KV7 channel active drugs has been to identify compounds capable of discriminating between the neuronally expressed subtypes (KV7.2–5), aiding the identification of the subunit composition of KV7 currents in various tissues, and possessing better therapeutic potential for particular indications. By taking advantage of the structure-activity relationship of acrylamide KV7 channel openers and the effects of these compounds on mutant KV7 channels, we have designed and synthesized a novel KV7 channel modulator with a unique profile. The compound, named SMB-1, is an inhibitor of KV7.2 and an activator of KV7.4. SMB-1 inhibits KV7.2 by reducing the current amplitude and increasing the time constant for the slow component of the activation kinetics. The activation of KV7.4 is seen as an increase in the current amplitude and a slowing of the deactivation kinetics. Experiments studying mutant channels with a compromised binding site for the KV7.2–5 opener retigabine indicate that SMB-1 binds within the same pocket as retigabine for both inhibition of KV7.2 and activation of KV7.4. SMB-1 may serve as a valuable tool for KV7 channel research and may be used as a template for further design of better subtype selective KV7 channel modulators. A compound with this profile could hold novel therapeutic potential such as the treatment of both positive and cognitive symptoms in schizophrenia.
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Affiliation(s)
- Sigrid Marie Blom
- Division of Neuroscience Drug Discovery, H. Lundbeck A/S, Copenhagen, Denmark
- Department of Biomedical Sciences and Danish National Research Foundation Centre for Cardiac Arrhythmia, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mario Rottländer
- Division of Discovery Chemistry and DMPK, H. Lundbeck A/S, Copenhagen, Denmark
| | - Jan Kehler
- Division of Discovery Chemistry and DMPK, H. Lundbeck A/S, Copenhagen, Denmark
| | | | - Nicole Schmitt
- Department of Biomedical Sciences and Danish National Research Foundation Centre for Cardiac Arrhythmia, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Sindal Jensen
- Division of Neuroscience Drug Discovery, H. Lundbeck A/S, Copenhagen, Denmark
- * E-mail:
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31
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Knapp CM, O'Malley M, Datta S, Ciraulo DA. The Kv7 potassium channel activator retigabine decreases alcohol consumption in rats. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2014; 40:244-50. [PMID: 24735395 DOI: 10.3109/00952990.2014.892951] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Activation of Kv7 potassium channels may decrease the reactivity of mesolimbic dopaminergic neurons that are implicated in mediating the reinforcing effects of ethanol. OBJECTIVES The objective of this study was to determine whether the administration of the Kv7 potassium channel opener retigabine would decrease ethanol intake in Long Evans rats. METHODS A limited access two-bottle choice model of alcohol (10% solution) consumption was used in this study. A separate group of animals was tested to evaluate the actions of retigabine on sucrose (5% solution) consumption to determine whether this drug might produce non-selective impairment of the ability of rats to drink liquids. Animals were treated with either vehicle or increasing doses (2.5-7.5 mg/kg SC) of retigabine administered over a 3-day period. RESULTS Compared to vehicle, retigabine at a dose of 7.5 mg/kg produced a reduction in the amount of ethanol consumed. These effects did not occur in association with significant changes in water consumption. A significant time effect was found for the actions of retigabine in sucrose-drinking rats with a trend for an increase in sucrose intake with the highest dose of retigabine administered. CONCLUSIONS These results indicate that the administration of retigabine may produce a decrease in ethanol consumption by rats at doses that do not significantly reduce the drinking of either water or a sucrose solution. These findings are consistent with the hypothesis that activation of Kv7 channels facilitates the reduction of alcohol consumption in the rat.
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Grunnet M, Strøbæk D, Hougaard C, Christophersen P. Kv7 channels as targets for anti-epileptic and psychiatric drug-development. Eur J Pharmacol 2014; 726:133-7. [PMID: 24457124 DOI: 10.1016/j.ejphar.2014.01.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 12/16/2013] [Accepted: 01/06/2014] [Indexed: 11/18/2022]
Abstract
The Kv7 channels, a family of voltage-dependent K(+) channels (Kv7.1-Kv7.5), have gained much attention in drug discovery especially because four members are genetically linked to diseases. For disorders of the CNS focus was originally on epilepsy and pain, but it is becoming increasingly evident that Kv7 channels can also be valid targets for psychiatric disorders, such as anxiety and mania. The common denominator is probably neuronal hyperexcitability in different brain areas, which can be successfully attenuated by pharmacological increment of Kv7 channel activity. This perspective attempts to review the current status and challenges for CNS drug discovery based on Kv7 channels as targets for neurological and psychiatric indications with special focus on selectivity and mode-of-actions.
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Affiliation(s)
- Morten Grunnet
- Lundbeck Pharma A/S, Ottiliavej 9 Valby, DK2500, Denmark
| | - Dorte Strøbæk
- Aniona Aps, Baltorpvej 154, Ballerup DK2750, Denmark
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Sørensen G, Husum H, Brennum LT, Bundgaard C, Montezinho LCP, Mørk A, Wörtwein G, Woldbye DPD. Addiction-Related Effects of DOV 216,303 and Cocaine: A Comparative Study in the Mouse. Basic Clin Pharmacol Toxicol 2014; 114:451-9. [DOI: 10.1111/bcpt.12182] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 11/27/2013] [Indexed: 12/01/2022]
Affiliation(s)
- Gunnar Sørensen
- Laboratory of Neuropsychiatry; Department of Neuroscience and Pharmacology; Rigshospitalet University Hospital; University of Copenhagen; Copenhagen Denmark
| | | | | | | | | | - Arne Mørk
- Synaptic Transmission; H. Lundbeck A/S; Copenhagen Denmark
| | - Gitta Wörtwein
- Laboratory of Neuropsychiatry; Department of Neuroscience and Pharmacology; Rigshospitalet University Hospital; University of Copenhagen; Copenhagen Denmark
| | - David P. D. Woldbye
- Laboratory of Neural Plasticity; Department of Neuroscience and Pharmacology; University of Copenhagen; Copenhagen Denmark
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Shah NH, Aizenman E. Voltage-gated potassium channels at the crossroads of neuronal function, ischemic tolerance, and neurodegeneration. Transl Stroke Res 2013; 5:38-58. [PMID: 24323720 DOI: 10.1007/s12975-013-0297-7] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 09/14/2013] [Accepted: 10/14/2013] [Indexed: 11/29/2022]
Abstract
Voltage-gated potassium (Kv) channels are widely expressed in the central and peripheral nervous system and are crucial mediators of neuronal excitability. Importantly, these channels also actively participate in cellular and molecular signaling pathways that regulate the life and death of neurons. Injury-mediated increased K(+) efflux through Kv2.1 channels promotes neuronal apoptosis, contributing to widespread neuronal loss in neurodegenerative disorders such as Alzheimer's disease and stroke. In contrast, some forms of neuronal activity can dramatically alter Kv2.1 channel phosphorylation levels and influence their localization. These changes are normally accompanied by modifications in channel voltage dependence, which may be neuroprotective within the context of ischemic injury. Kv1 and Kv7 channel dysfunction leads to neuronal hyperexcitability that critically contributes to the pathophysiology of human clinical disorders such as episodic ataxia and epilepsy. This review summarizes the neurotoxic, neuroprotective, and neuroregulatory roles of Kv channels and highlights the consequences of Kv channel dysfunction on neuronal physiology. The studies described in this review thus underscore the importance of normal Kv channel function in neurons and emphasize the therapeutic potential of targeting Kv channels in the treatment of a wide range of neurological diseases.
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Affiliation(s)
- Niyathi Hegde Shah
- Department of Neurobiology, University of Pittsburgh School of Medicine, 3500 Terrace Street, E1456 BST, Pittsburgh, PA, 15261, USA,
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Waszkielewicz AM, Gunia A, Szkaradek N, Słoczyńska K, Krupińska S, Marona H. Ion channels as drug targets in central nervous system disorders. Curr Med Chem 2013; 20:1241-85. [PMID: 23409712 PMCID: PMC3706965 DOI: 10.2174/0929867311320100005] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 01/14/2013] [Accepted: 01/18/2013] [Indexed: 12/27/2022]
Abstract
Ion channel targeted drugs have always been related with either the central nervous system (CNS), the peripheral nervous system, or the cardiovascular system. Within the CNS, basic indications of drugs are: sleep disorders, anxiety, epilepsy, pain, etc. However, traditional channel blockers have multiple adverse events, mainly due to low specificity of mechanism of action. Lately, novel ion channel subtypes have been discovered, which gives premises to drug discovery process led towards specific channel subtypes. An example is Na(+) channels, whose subtypes 1.3 and 1.7-1.9 are responsible for pain, and 1.1 and 1.2 - for epilepsy. Moreover, new drug candidates have been recognized. This review is focusing on ion channels subtypes, which play a significant role in current drug discovery and development process. The knowledge on channel subtypes has developed rapidly, giving new nomenclatures of ion channels. For example, Ca(2+)s channels are not any more divided to T, L, N, P/Q, and R, but they are described as Ca(v)1.1-Ca(v)3.3, with even newer nomenclature α1A-α1I and α1S. Moreover, new channels such as P2X1-P2X7, as well as TRPA1-TRPV1 have been discovered, giving premises for new types of analgesic drugs.
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Affiliation(s)
- A M Waszkielewicz
- Department of Bioorganic Chemistry, Chair of Organic Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Krakow, Poland.
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Jensen ML, Wafford KA, Brown AR, Belelli D, Lambert JJ, Mirza NR. A study of subunit selectivity, mechanism and site of action of the delta selective compound 2 (DS2) at human recombinant and rodent native GABA(A) receptors. Br J Pharmacol 2013; 168:1118-32. [PMID: 23061935 DOI: 10.1111/bph.12001] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 07/18/2012] [Accepted: 08/23/2012] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND AND PURPOSE Most GABA(A) receptor subtypes comprise 2α, 2β and 1γ subunit, although for some isoforms, a δ replaces a γ-subunit. Extrasynaptic δ-GABA(A) receptors are important therapeutic targets, but there are few suitable pharmacological tools. We profiled DS2, the purported positive allosteric modulator (PAM) of δ-GABA(A) receptors to better understand subtype selectivity, mechanism/site of action and activity at native δ-GABA(A) receptors. EXPERIMENTAL APPROACH Subunit specificity of DS2 was determined using electrophysiological recordings of Xenopus laevis oocytes expressing human recombinant GABA(A) receptor isoforms. Effects of DS2 on GABA concentration-response curves were assessed to define mechanisms of action. Radioligand binding and electrophysiology utilising mutant receptors and pharmacology were used to define site of action. Using brain-slice electrophysiology, we assessed the influence of DS2 on thalamic inhibition in wild-type and δ(0/0) mice. KEY RESULTS Actions of DS2 were primarily determined by the δ-subunit but were additionally influenced by the α, but not the β, subunit (α4/6βxδ > α1βxδ >> γ2-GABA(A) receptors > α4β3). For δ-GABA(A) receptors, DS2 enhanced maximum responses to GABA, with minimal influence on GABA potency. (iii) DS2 did not act via the orthosteric, or known modulatory sites on GABA(A) receptors. (iv) DS2 enhanced tonic currents of thalamocortical neurones from wild-type but not δ(0/0) mice. CONCLUSIONS AND IMPLICATIONS DS2 is the first PAM selective for α4/6βxδ receptors, providing a novel tool to investigate extrasynaptic δ-GABA(A) receptors. The effects of DS2 are mediated by an unknown site leading to GABA(A) receptor isoform selectivity.
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Fujimoto H, Liu HX, Lopatina O, Brown DA, Higashida H. Scopolamine modulates paternal parental retrieval behavior in mice induced by the maternal mate. Neurosci Lett 2013; 546:63-6. [DOI: 10.1016/j.neulet.2013.04.059] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Revised: 04/25/2013] [Accepted: 04/28/2013] [Indexed: 11/24/2022]
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Imbrici P, Camerino DC, Tricarico D. Major channels involved in neuropsychiatric disorders and therapeutic perspectives. Front Genet 2013; 4:76. [PMID: 23675382 PMCID: PMC3646240 DOI: 10.3389/fgene.2013.00076] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 04/16/2013] [Indexed: 12/11/2022] Open
Abstract
Voltage-gated ion channels are important mediators of physiological functions in the central nervous system. The cyclic activation of these channels influences neurotransmitter release, neuron excitability, gene transcription, and plasticity, providing distinct brain areas with unique physiological and pharmacological response. A growing body of data has implicated ion channels in the susceptibility or pathogenesis of psychiatric diseases. Indeed, population studies support the association of polymorphisms in calcium and potassium channels with the genetic risk for bipolar disorders (BPDs) or schizophrenia. Moreover, point mutations in calcium, sodium, and potassium channel genes have been identified in some childhood developmental disorders. Finally, antibodies against potassium channel complexes occur in a series of autoimmune psychiatric diseases. Here we report recent studies assessing the role of calcium, sodium, and potassium channels in BPD, schizophrenia, and autism spectrum disorders, and briefly summarize promising pharmacological strategies targeted on ion channels for the therapy of mental illness and related genetic tests.
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Affiliation(s)
- Paola Imbrici
- Section of Pharmacology, Department of Pharmacy - Drug Science, University of Bari Bari, Italy
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Dalby-Brown W, Jessen C, Hougaard C, Jensen ML, Jacobsen TA, Nielsen KS, Erichsen HK, Grunnet M, Ahring PK, Christophersen P, Strøbæk D, Jørgensen S. Characterization of a novel high-potency positive modulator of K(v)7 channels. Eur J Pharmacol 2013; 709:52-63. [PMID: 23562623 DOI: 10.1016/j.ejphar.2013.03.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 03/15/2013] [Accepted: 03/24/2013] [Indexed: 01/11/2023]
Abstract
K(v)7 channel activators decrease neuronal excitability and might potentially treat neuronal hyperexcitability disorders like epilepsy and mania. Here we introduce NS15370 ((2-(3,5-difluorophenyl)-N-[6-[(4-fluorophenyl)methylamino]-2-morpholino-3-pyridyl]acetamide)hydrochloride, an in vitro high-potency chemical analogue of retigabine, without effects on GABA(A) receptors. NS15370 activates recombinant homo- and heteromeric K(v)7.2-K(v)7.5 channels in HEK293 cells at sub-micromolar concentrations (EC₅₀~100 nM, as quantified by a fluorescence based Tl⁺-influx assay). In voltage clamp experiments NS15370 exhibits a complex, concentration-dependent mode-of-action: At low concentrations it accelerates voltage-dependent activation rates, slows deactivations, and increases steady-state current amplitudes. Quantified by the peak-tail current method, the V½ value of the steady-state activation curve is shifted towards hyperpolarized potentials at concentrations ~100 times lower than retigabine. However, in contrast to retigabine, NS15370 also introduces a distinct time-dependent current decrease, which eventually, at higher concentrations, causes suppression of the current at depolarized potentials, and an apparent "cross-over" of the voltage-activation curve. In brain slices, NS15370 hyperpolarizes and increases spike frequency adaptation of hippocampal CA1 neurons and the compound reduces the autonomous firing of dopaminergic neurons in the substantia-nigra pars compacta. NS15370 is effective in rodent models of hyperexcitability: (i) it yields full protection against mouse 6 Hz seizures and rat amygdala kindling discharges, two models of partial epilepsia; (ii) it reduces (+)-MK-801 hydrogen maleate (MK-801)-induced hyperactivity as well as chlordiazepoxide (CDP)+d-amphetamine (AMP)-induced hyperactivity, models sensitive to classic anti-psychotic and anti-manic treatments, respectively. Our findings with NS15370 consolidate neuronal K(v)7 channels as targets for anti-epileptic and psychiatric drug development.
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Hosseinzadeh Z, Sopjani M, Pakladok T, Bhavsar SK, Lang F. Downregulation of KCNQ4 by Janus kinase 2. J Membr Biol 2013; 246:335-41. [PMID: 23543186 DOI: 10.1007/s00232-013-9537-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 03/16/2013] [Indexed: 12/19/2022]
Abstract
Janus kinase-2 (JAK2) participates in the signaling of several hormones, growth factors and cytokines. Further stimulators of JAK2 include osmotic cell shrinkage, and the kinase activates the cell volume regulatory Na(+)/H(+) exchanger. The kinase may thus participate in cell volume regulation. Cell shrinkage is known to inhibit K(+) channels. Volume-regulatory K(+) channels include the voltage-gated K(+) channel KCNQ4. The present study explored the effect of JAK2 on KCNQ4 channel activity. KCNQ4 was expressed in Xenopus oocytes with or without wild-type JAK2, constitutively active (V617F)JAK2 or inactive (K882E)JAK2; and cell membrane conductance was determined by dual-electrode voltage clamp. Expression of KCNQ4 was followed by the appearance of voltage-gated K(+) conductance. Coexpression of JAK2 or of (V617F)JAK2, but not of (K882E)JAK2, resulted in a significant decrease in conductance. Treatment of KCNQ4 and JAK2 coexpressing oocytes with the JAK2 inhibitor AG490 (40 μM) was followed by an increase in conductance. Treatment of KCNQ4 expressing oocytes with brefeldin A (5 μM) was followed by a decrease in conductance, which was similar in oocytes expressing KCNQ4 together with JAK2 as in oocytes expressing KCNQ4 alone. Thus, JAK2 apparently does not accelerate channel protein retrieval from the cell membrane. In conclusion, JAK2 downregulates KCNQ4 activity and thus counteracts K(+) exit, an effect which may contribute to cell volume regulation.
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Redrobe JP, Elster L, Frederiksen K, Bundgaard C, de Jong IEM, Smith GP, Bruun AT, Larsen PH, Didriksen M. Negative modulation of GABAA α5 receptors by RO4938581 attenuates discrete sub-chronic and early postnatal phencyclidine (PCP)-induced cognitive deficits in rats. Psychopharmacology (Berl) 2012; 221:451-68. [PMID: 22124672 DOI: 10.1007/s00213-011-2593-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 11/15/2011] [Indexed: 11/29/2022]
Abstract
RATIONALE A growing body of evidence suggests that negative modulation of γ-aminobutyric acid (GABA) GABA(A) α5 receptors may be a promising strategy for the treatment of certain facets of cognitive impairment; however, selective modulators of GABA(A) α5 receptors have not yet been tested in "schizophrenia-relevant" cognitive assay/model systems in animals. OBJECTIVES The objectives of this study were to investigate the potential of RO4938581, a negative modulator of GABA(A) α5 receptors, and to attenuate cognitive impairments induced following sub-chronic (sub-PCP) and early postnatal PCP (neo-PCP) administration in the novel object recognition (NOR) and intra-extradimensional shift (ID/ED) paradigms in rats. Complementary in vitro, ex vivo and in vivo studies were performed to confirm negative modulatory activity of RO4938581 and to investigate animal model validity, concept validity and potential side effect issues, respectively. RESULTS In vitro studies confirmed the reported negative modulatory activity of RO4938581, whilst immunohistochemical analyses revealed significantly reduced parvalbumin-positive cells in the prefrontal cortex of sub-PCP- and neo-PCP-treated rats. RO4938581 (1 mg/kg) ameliorated both sub-PCP- and neo-PCP-induced cognitive deficits in NOR and ID/ED performance, respectively. In contrast, QH-II-066 (1 and 3 mg/kg), a GABA(A) α5 receptor positive modulator, impaired cognitive performance in the NOR task when administered to vehicle-treated animals. Additional studies revealed that both RO4938581 (1 mg/kg) and QH-II-066 (1 and 3 mg/kg) attenuated amphetamine-induced hyperactivity in rats. CONCLUSIONS Taken together, these novel findings suggest that negative modulation of GABA(A) α5 receptors may represent an attractive treatment option for the cognitive impairments, and potentially positive symptoms, associated with schizophrenia.
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Affiliation(s)
- John P Redrobe
- Synaptic Transmission I, Neuroscience Research DK, H Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark.
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Affiliation(s)
- Kyoung Heo
- Department of Neurology, Yonsei University College of Medicine, Seoul, Korea
- Epilepsy Research Institute, Yonsei University College of Medicine, Seoul, Korea
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Vukadinovic Z, Rosenzweig I. Abnormalities in thalamic neurophysiology in schizophrenia: could psychosis be a result of potassium channel dysfunction? Neurosci Biobehav Rev 2011; 36:960-8. [PMID: 22138503 DOI: 10.1016/j.neubiorev.2011.11.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2011] [Revised: 11/11/2011] [Accepted: 11/20/2011] [Indexed: 10/14/2022]
Abstract
Psychosis in schizophrenia is associated with source-monitoring deficits whereby self-initiated behaviors become attributed to outside sources. One of the proposed functions of the thalamus is to adjust sensory responsiveness in accordance with the behavioral contextual cues. The thalamus is markedly affected in schizophrenia, and thalamic dysfunction may here result in reduced ability to adjust sensory responsiveness to ongoing behavior. One of the ways in which the thalamus accomplishes the adjustment of sensory processing is by a neurophysiological shift to post-inhibitory burst firing mode prior to and during certain exploratory actions. Reduced amount of thalamic burst firing may result from increased neuronal excitability secondary to a reported potassium channel dysfunction in schizophrenia. Pharmacological agents that reduce the excitability of thalamic cells and thereby promote burst firing by and large tend to have antipsychotic effects.
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Affiliation(s)
- Zoran Vukadinovic
- Montefiore Medical Center, Albert Einstein College of Medicine, Department of Psychiatry and Behavioral Sciences, 111 E 210th Street, Bronx, NY 10467, USA.
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Ion channels and schizophrenia: a gene set-based analytic approach to GWAS data for biological hypothesis testing. Hum Genet 2011; 131:373-91. [PMID: 21866342 DOI: 10.1007/s00439-011-1082-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 08/08/2011] [Indexed: 01/11/2023]
Abstract
Schizophrenia is a complex genetic disorder. Gene set-based analytic (GSA) methods have been widely applied for exploratory analyses of large, high-throughput datasets, but less commonly employed for biological hypothesis testing. Our primary hypothesis is that variation in ion channel genes contribute to the genetic susceptibility to schizophrenia. We applied Exploratory Visual Analysis (EVA), one GSA application, to analyze European-American (EA) and African-American (AA) schizophrenia genome-wide association study datasets for statistical enrichment of ion channel gene sets, comparing GSA results derived under three SNP-to-gene mapping strategies: (1) GENIC; (2) 500-Kb; (3) 2.5-Mb and three complimentary SNP-to-gene statistical reduction methods: (1) minimum p value (pMIN); (2) a novel method, proportion of SNPs per Gene with p values below a pre-defined α-threshold (PROP); and (3) the truncated product method (TPM). In the EA analyses, ion channel gene set(s) were enriched under all mapping and statistical approaches. In the AA analysis, ion channel gene set(s) were significantly enriched under pMIN for all mapping strategies and under PROP for broader mapping strategies. Less extensive enrichment in the AA sample may reflect true ethnic differences in susceptibility, sampling or case ascertainment differences, or higher dimensionality relative to sample size of the AA data. More consistent findings under broader mapping strategies may reflect enhanced power due to increased SNP inclusion, enhanced capture of effects over extended haplotypes or significant contributions from regulatory regions. While extensive pMIN findings may reflect gene size bias, the extent and significance of PROP and TPM findings suggest that common variation at ion channel genes may capture some of the heritability of schizophrenia.
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Deemyad T, Maler L, Chacron MJ. Inhibition of SK and M channel-mediated currents by 5-HT enables parallel processing by bursts and isolated spikes. J Neurophysiol 2011; 105:1276-94. [PMID: 21209357 PMCID: PMC4850069 DOI: 10.1152/jn.00792.2010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Although serotonergic innervation of sensory brain areas is ubiquitous, its effects on sensory information processing remain poorly understood. We investigated these effects in pyramidal neurons within the electrosensory lateral line lobe (ELL) of weakly electric fish. Surprisingly, we found that 5-HT is present at different levels across the different ELL maps; the presence of 5-HT fibers was highest in the map that processes intraspecies communication signals. Electrophysiological recordings revealed that 5-HT increased excitability and burst firing through a decreased medium afterhyperpolarization resulting from reduced small-conductance calcium-activated (SK) currents as well as currents mediated by an M-type potassium channel. We next investigated how 5-HT alters responses to sensory input. 5-HT application decreased the rheobase current, increased the gain, and decreased first spike latency. Moreover, it reduced discriminability between different stimuli, as quantified by the mutual information rate. We hypothesized that 5-HT shifts pyramidal neurons into a burst-firing mode where bursts, when considered as events, can detect the presence of particular stimulus features. We verified this hypothesis using signal detection theory. Our results indeed show that serotonin-induced bursts of action potentials, when considered as events, could detect specific stimulus features that were distinct from those detected by isolated spikes. Moreover, we show the novel result that isolated spikes transmit more information after 5-HT application. Our results suggest a novel function for 5-HT in that it enables differential processing by action potential patterns in response to current injection.
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Affiliation(s)
- Tara Deemyad
- Department of Physiology, McGill University, Montreal, Quebec, Canada
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Abstract
This article discusses seven newly available antiepileptic drugs (AEDs) and agents in phase III development. Lacosamide, licensed as an adjunctive treatment for partial-onset seizures, primarily acts by enhancing sodium channel slow inactivation. At daily doses of 200-600 mg, the drug significantly reduced partial-onset seizures in adults with refractory epilepsy. The most common adverse effects are CNS related. Rufinamide, available as adjunctive treatment for seizures associated with Lennox-Gastaut syndrome, has an unclear mechanism of action, although it does block voltage-dependent sodium channels. Coadministration of valproic acid significantly increases rufinamide circulating concentrations. The drug has been shown to have efficacy for partial-onset, primary generalized tonic-clonic, tonic-atonic, absence and atypical absence seizures. Adverse effects are mainly somnolence, nausea and vomiting. Eslicarbazepine acetate, a carbamazepine analogue, was recently licensed as adjunctive treatment for partial-onset seizures. Eslicarbazepine acetate acts at voltage-gated sodium channels, although the precise mechanism of action is unclear. The drug had efficacy for partial-onset seizures in three randomized, double-blind, placebo-controlled studies, using 400, 800 or 1200 mg/day. Adverse effects include dizziness and somnolence. Retigabine (ezogabine) exerts its anticonvulsant effect through the opening of neuronal voltage-gated potassium channels. Following significant seizure reduction rates at dosages of 600, 900 and 1200 mg/day, license applications have been submitted for its use as adjunctive treatment for patients with partial-onset seizures. Dose-related adverse effects include somnolence, confusion and dizziness. Brivaracetam is the n-propyl analogue of levetiracetam. Mixed results have been obtained in phase III studies in patients with partial-onset seizures, and further trials in children, patients with photosensitive epilepsy and patients with partial-onset seizures are ongoing. Dizziness, headache and somnolence are the most common adverse effects reported. Perampanel was designed as an AMPA-type glutamate receptor antagonist. Following encouraging results from phase II studies in patients with refractory partial-onset seizures, recruitment for phase III trials is almost complete. Ganaxolone is a neurosteroid with potent antiepileptic activity that modulates GABA(A) receptors in the CNS. Ganaxolone has shown promise in a variety of seizure types. Dizziness and somnolence have been reported in some patients. The availability of new AEDs has widened the choices for clinicians treating patients with epilepsy. However, given the minimal improvement in prognosis and disappointing efficacy outcomes in double-blind, placebo-controlled, dose-ranging regulatory trials, it seems unlikely that these novel agents will have a major impact on outcomes for people with epilepsy.
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Affiliation(s)
- Linda J Stephen
- Epilepsy Unit, Division of Cardiovascular and Medical Sciences, Western Infirmary, Glasgow, Scotland
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Kv7 (KCNQ) channel openers induce hypothermia in the mouse. Neurosci Lett 2011; 488:178-82. [DOI: 10.1016/j.neulet.2010.11.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 11/02/2010] [Accepted: 11/09/2010] [Indexed: 11/18/2022]
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Castle NA. Pharmacological modulation of voltage-gated potassium channels as a therapeutic strategy. Expert Opin Ther Pat 2010; 20:1471-503. [PMID: 20726689 DOI: 10.1517/13543776.2010.513384] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
IMPORTANCE OF THE FIELD The human genome encodes at least 40 distinct voltage-gated potassium channel subtypes, which vary in regional expression, pharmacological and biophysical properties. Voltage-dependent potassium (Kv) channels help orchestrate many of the physiological and pathophysiological processes that promote and sometimes hinder the healthy functioning of our bodies. AREAS COVERED IN THIS REVIEW This review summarizes patent and scientific literature reports from the past decade highlighting the opportunities that Kv channels offer for the development of new therapeutic interventions for a wide variety of disorders. WHAT THE READER WILL GAIN The reader will gain an insight from an analysis of the associations of different Kv family members with disease processes, summary and evaluation of the development of therapeutically relevant pharmacological modulators of these channels, particularly focusing on proprietary agents being developed. TAKE HOME MESSAGE Development of new drugs that target Kv channels continue to be of great interest but is proving to be challenging. Nevertheless, opportunities for Kv channel modulators to have an impact on a wide range of disorders in the future remain an exciting prospect.
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Drion G, Bonjean M, Waroux O, Scuvée-Moreau J, Liégeois JF, Sejnowski TJ, Sepulchre R, Seutin V. M-type channels selectively control bursting in rat dopaminergic neurons. Eur J Neurosci 2010; 31:827-35. [PMID: 20180842 PMCID: PMC2861736 DOI: 10.1111/j.1460-9568.2010.07107.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Midbrain dopaminergic neurons in the substantia nigra, pars compacta and ventral tegmental area are critically important in many physiological functions. These neurons exhibit firing patterns that include tonic slow pacemaking, irregular firing and bursting, and the amount of dopamine that is present in the synaptic cleft is much increased during bursting. The mechanisms responsible for the switch between these spiking patterns remain unclear. Using both in-vivo recordings combined with microiontophoretic or intraperitoneal drug applications and in-vitro experiments, we have found that M-type channels, which are present in midbrain dopaminergic cells, modulate the firing during bursting without affecting the background low-frequency pacemaker firing. Thus, a selective blocker of these channels, 10,10-bis(4-pyridinylmethyl)-9(10H)-anthracenone dihydrochloride, specifically potentiated burst firing. Computer modeling of the dopamine neuron confirmed the possibility of a differential influence of M-type channels on excitability during various firing patterns. Therefore, these channels may provide a novel target for the treatment of dopamine-related diseases, including Parkinson’s disease and drug addiction. Moreover, our results demonstrate that the influence of M-type channels on the excitability of these slow pacemaker neurons is conditional upon their firing pattern.
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Affiliation(s)
- Guillaume Drion
- Laboratory of Pharmacology and GIGA Neurosciences, University of Liège, Belgium
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Abstract
The human genome encodes 40 voltage-gated K(+) channels (K(V)), which are involved in diverse physiological processes ranging from repolarization of neuronal and cardiac action potentials, to regulating Ca(2+) signalling and cell volume, to driving cellular proliferation and migration. K(V) channels offer tremendous opportunities for the development of new drugs to treat cancer, autoimmune diseases and metabolic, neurological and cardiovascular disorders. This Review discusses pharmacological strategies for targeting K(V) channels with venom peptides, antibodies and small molecules, and highlights recent progress in the preclinical and clinical development of drugs targeting the K(V)1 subfamily, the K(V)7 subfamily (also known as KCNQ), K(V)10.1 (also known as EAG1 and KCNH1) and K(V)11.1 (also known as HERG and KCNH2) channels.
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