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Kovyazina IV, Khamidullina AA. Muscarinic Cholinoreceptors in Skeletal Muscle: Localization and Functional Role. Acta Naturae 2023; 15:44-55. [PMID: 38234599 PMCID: PMC10790362 DOI: 10.32607/actanaturae.25259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 09/24/2023] [Indexed: 01/19/2024] Open
Abstract
The review focuses on the modern concepts of the functions of muscarinic cholinoreceptors in skeletal muscles, particularly, in neuromuscular contacts, and that of the signaling pathways associated with the activation of various subtypes of muscarinic receptors in the skeletal muscles of cold-blooded and warm-blooded animals. Despite the long history of research into the involvement of muscarinic receptors in the modulation of neuromuscular transmission, many aspects of such regulation and the associated intracellular mechanisms remain unclear. Now it is obvious that the functions of muscarinic receptors in skeletal muscle are not limited to the autoregulation of neurosecretion from motor nerve endings but also extend to the development and morphological rearrangements of the synaptic apparatus, coordinating them with the degree of activity. The review discusses various approaches to the study of the functions of muscarinic receptors in motor synapses, as well as the problems arising when interpreting experimental data. The final part of the review is devoted to an analysis of some of the intracellular mechanisms and signaling pathways that mediate the effects of muscarinic agents on neuromuscular transmission.
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Affiliation(s)
- I. V. Kovyazina
- Kazan State Medical University, Kazan, 420012 Russian Federation
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, Kazan, 420111 Russian Federation
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Ngomba RT, Lüttjohann A, Dexter A, Ray S, van Luijtelaar G. The Metabotropic Glutamate 5 Receptor in Sleep and Wakefulness: Focus on the Cortico-Thalamo-Cortical Oscillations. Cells 2023; 12:1761. [PMID: 37443795 PMCID: PMC10341329 DOI: 10.3390/cells12131761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/17/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
Sleep is an essential innate but complex behaviour which is ubiquitous in the animal kingdom. Our knowledge of the distinct neural circuit mechanisms that regulate sleep and wake states in the brain are, however, still limited. It is therefore important to understand how these circuits operate during health and disease. This review will highlight the function of mGlu5 receptors within the thalamocortical circuitry in physiological and pathological sleep states. We will also evaluate the potential of targeting mGlu5 receptors as a therapeutic strategy for sleep disorders that often co-occur with epileptic seizures.
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Affiliation(s)
| | - Annika Lüttjohann
- Institute of Physiology I, University of Münster, 48149 Münster, Germany
| | - Aaron Dexter
- School of Pharmacy, University of Lincoln, Lincoln LN6 7DL, UK
| | - Swagat Ray
- Department of Life Sciences, School of Life and Environmental Sciences, University of Lincoln, Lincoln LN6 7DL, UK
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Schroeter CB, Nelke C, Schewe M, Spohler L, Herrmann AM, Müntefering T, Huntemann N, Kuzikov M, Gribbon P, Albrecht S, Bock S, Hundehege P, Neelsen LC, Baukrowitz T, Seebohm G, Wünsch B, Bittner S, Ruck T, Budde T, Meuth SG. Validation of TREK1 ion channel activators as an immunomodulatory and neuroprotective strategy in neuroinflammation. Biol Chem 2023; 404:355-375. [PMID: 36774650 DOI: 10.1515/hsz-2022-0266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 01/16/2023] [Indexed: 02/13/2023]
Abstract
Modulation of two-pore domain potassium (K2P) channels has emerged as a novel field of therapeutic strategies as they may regulate immune cell activation and metabolism, inflammatory signals, or barrier integrity. One of these ion channels is the TWIK-related potassium channel 1 (TREK1). In the current study, we report the identification and validation of new TREK1 activators. Firstly, we used a modified potassium ion channel assay to perform high-throughput-screening of new TREK1 activators. Dose-response studies helped to identify compounds with a high separation between effectiveness and toxicity. Inside-out patch-clamp measurements of Xenopus laevis oocytes expressing TREK1 were used for further validation of these activators regarding specificity and activity. These approaches yielded three substances, E1, B3 and A2 that robustly activate TREK1. Functionally, we demonstrated that these compounds reduce levels of adhesion molecules on primary human brain and muscle endothelial cells without affecting cell viability. Finally, we studied compound A2 via voltage-clamp recordings as this activator displayed the strongest effect on adhesion molecules. Interestingly, A2 lacked TREK1 activation in the tested neuronal cell type. Taken together, this study provides data on novel TREK1 activators that might be employed to pharmacologically modulate TREK1 activity.
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Affiliation(s)
- Christina B Schroeter
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Christopher Nelke
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Marcus Schewe
- Institute of Physiology, Christian-Albrechts University Kiel, Hermann-Rodewald-Straße 5, 24118 Kiel, Germany
| | - Lucas Spohler
- Department of Neurology with Institute for Translational Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
| | - Alexander M Herrmann
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Thomas Müntefering
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Niklas Huntemann
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Maria Kuzikov
- Fraunhofer Institute for Translational Medicine and Pharmacology (ITMP), Schnackenburgallee 114, D-22525 Hamburg, Germany
- Fraunhofer Cluster of Excellence for Immune mediated diseases (CIMD), Theodor-Stern-Kai 7, D-60596 Frankfurt, Germany
| | - Philip Gribbon
- Fraunhofer Institute for Translational Medicine and Pharmacology (ITMP), Schnackenburgallee 114, D-22525 Hamburg, Germany
- Fraunhofer Cluster of Excellence for Immune mediated diseases (CIMD), Theodor-Stern-Kai 7, D-60596 Frankfurt, Germany
| | - Sarah Albrecht
- Department of Neurology with Institute for Translational Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
| | - Stefanie Bock
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Petra Hundehege
- Department of Neurology with Institute for Translational Neurology, University Hospital Münster, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
| | - Lea Christine Neelsen
- Institute of Physiology, Christian-Albrechts University Kiel, Hermann-Rodewald-Straße 5, 24118 Kiel, Germany
| | - Thomas Baukrowitz
- Institute of Physiology, Christian-Albrechts University Kiel, Hermann-Rodewald-Straße 5, 24118 Kiel, Germany
| | - Guiscard Seebohm
- IfGH-Cellular Electrophysiology, Department of Cardiology and Angiology, University Hospital of Münster, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
| | - Bernhard Wünsch
- Institute for Pharmaceutical and Medicinal Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstraße 48, D-48149 Münster, Germany
| | - Stefan Bittner
- Department of Neurology, University Medical Center Mainz, Langenbeckstraße 1, D-55131 Mainz, Germany
| | - Tobias Ruck
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
| | - Thomas Budde
- Institute of Physiology I, University of Münster, Robert-Koch-Straße 27A, D-48149 Münster, Germany
| | - Sven G Meuth
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Moorenstr. 5, D-40225 Düsseldorf, Germany
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Fan X, Lu Y, Du G, Liu J. Advances in the Understanding of Two-Pore Domain TASK Potassium Channels and Their Potential as Therapeutic Targets. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238296. [PMID: 36500386 PMCID: PMC9736439 DOI: 10.3390/molecules27238296] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/09/2022] [Accepted: 11/15/2022] [Indexed: 11/29/2022]
Abstract
TWIK-related acid-sensitive K+ (TASK) channels, including TASK-1, TASK-3, and TASK-5, are important members of the two-pore domain potassium (K2P) channel family. TASK-5 is not functionally expressed in the recombinant system. TASK channels are very sensitive to changes in extracellular pH and are active during all membrane potential periods. They are similar to other K2P channels in that they can create and use background-leaked potassium currents to stabilize resting membrane conductance and repolarize the action potential of excitable cells. TASK channels are expressed in both the nervous system and peripheral tissues, including excitable and non-excitable cells, and are widely engaged in pathophysiological phenomena, such as respiratory stimulation, pulmonary hypertension, arrhythmia, aldosterone secretion, cancers, anesthesia, neurological disorders, glucose homeostasis, and visual sensitivity. Therefore, they are important targets for innovative drug development. In this review, we emphasized the recent advances in our understanding of the biophysical properties, gating profiles, and biological roles of TASK channels. Given the different localization ranges and biologically relevant functions of TASK-1 and TASK-3 channels, the development of compounds that selectively target TASK-1 and TASK-3 channels is also summarized based on data reported in the literature.
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Affiliation(s)
- Xueming Fan
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Department of Anesthesiology, Guizhou Provincial People’s Hospital, Guiyang 550002, China
| | - Yongzhi Lu
- Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510700, China
| | - Guizhi Du
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Correspondence: (G.D.); (J.L.)
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Correspondence: (G.D.); (J.L.)
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Deficiency of the Two-Pore Potassium Channel KCNK9 Impairs Intestinal Epithelial Cell Survival and Aggravates Dextran Sodium Sulfate-Induced Colitis. Cell Mol Gastroenterol Hepatol 2022; 14:1199-1211. [PMID: 35973573 PMCID: PMC9579309 DOI: 10.1016/j.jcmgh.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 08/10/2022] [Accepted: 08/10/2022] [Indexed: 01/31/2023]
Abstract
BACKGROUND & AIMS The 2-pore potassium channel subfamily K member 9 (KCNK9) regulates intracellular calcium concentration and thus modulates cell survival and inflammatory signaling pathways. It also was recognized as a risk allele for inflammatory bowel disease. However, it remains unclear whether KCNK9 modulates inflammatory bowel disease via its impact on immune cell function or whether its influence on calcium homeostasis also is relevant in intestinal epithelial cells. METHODS Kcnk9-/- mice were challenged with 3% dextran sulfate sodium (DSS) to induce experimental acute colitis. Primary cultures of intestinal epithelial cells were generated, and expression of potassium channels as well as cytosolic calcium levels and susceptibility to apoptosis were evaluated. Furthermore, we evaluated whether KCNK9 deficiency was compensated by the closely related 2-pore potassium channel KCNK3 in vivo or in vitro. RESULTS Compared with controls, KCNK9 deficiency or its pharmacologic blockade were associated with aggravated DSS-induced colitis compared with wild-type animals. In the absence of KCNK9, intestinal epithelial cells showed increased intracellular calcium levels and were more prone to mitochondrial damage and caspase-9-dependent apoptosis. We found that expression of KCNK3 was increased in Kcnk9-/- mice but did not prevent apoptosis after DSS exposure. Conversely, increased levels of KCNK9 in Kcnk3-/- mice were associated with an ameliorated course of DSS-induced colitis. CONCLUSIONS KCNK9 enhances mitochondrial stability, reduces apoptosis, und thus supports epithelial cell survival after DSS exposure in vivo and in vitro. Conversely, its increased expression in Kcnk3-/- resulted in less mitochondrial damage and apoptosis and was associated with beneficial outcomes in DSS-induced colitis.
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Oniani T, Vinnenberg L, Chaudhary R, Schreiber JA, Riske K, Williams B, Pape HC, White JA, Junker A, Seebohm G, Meuth SG, Hundehege P, Budde T, Zobeiri M. Effects of Axonal Demyelination, Inflammatory Cytokines and Divalent Cation Chelators on Thalamic HCN Channels and Oscillatory Bursting. Int J Mol Sci 2022; 23:ijms23116285. [PMID: 35682964 PMCID: PMC9181513 DOI: 10.3390/ijms23116285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/31/2022] [Accepted: 05/31/2022] [Indexed: 12/13/2022] Open
Abstract
Multiple sclerosis (MS) is a demyelinating disease of the central nervous system that is characterized by the progressive loss of oligodendrocytes and myelin and is associated with thalamic dysfunction. Cuprizone (CPZ)-induced general demyelination in rodents is a valuable model for studying different aspects of MS pathology. CPZ feeding is associated with the altered distribution and expression of different ion channels along neuronal somata and axons. However, it is largely unknown whether the copper chelator CPZ directly influences ion channels. Therefore, we assessed the effects of different divalent cations (copper; zinc) and trace metal chelators (EDTA; Tricine; the water-soluble derivative of CPZ, BiMPi) on hyperpolarization-activated cyclic nucleotide-gated (HCN) channels that are major mediators of thalamic function and pathology. In addition, alterations of HCN channels induced by CPZ treatment and MS-related proinflammatory cytokines (IL-1β; IL-6; INF-α; INF-β) were characterized in C57Bl/6J mice. Thus, the hyperpolarization-activated inward current (Ih) was recorded in thalamocortical (TC) neurons and heterologous expression systems (mHCN2 expressing HEK cells; hHCN4 expressing oocytes). A number of electrophysiological characteristics of Ih (potential of half-maximal activation (V0.5); current density; activation kinetics) were unchanged following the extracellular application of trace metals and divalent cation chelators to native neurons, cell cultures or oocytes. Mice were fed a diet containing 0.2% CPZ for 35 days, resulting in general demyelination in the brain. Withdrawal of CPZ from the diet resulted in rapid remyelination, the effects of which were assessed at three time points after stopping CPZ feeding (Day1, Day7, Day25). In TC neurons, Ih was decreased on Day1 and Day25 and revealed a transient increased availability on Day7. In addition, we challenged naive TC neurons with INF-α and IL-1β. It was found that Ih parameters were differentially altered by the application of the two cytokines to thalamic cells, while IL-1β increased the availability of HCN channels (depolarized V0.5; increased current density) and the excitability of TC neurons (depolarized resting membrane potential (RMP); increased the number of action potentials (APs); produced a larger voltage sag; promoted higher input resistance; increased the number of burst spikes; hyperpolarized the AP threshold), INF-α mediated contrary effects. The effect of cytokine modulation on thalamic bursting was further assessed in horizontal slices and a computational model of slow thalamic oscillations. Here, IL-1β and INF-α increased and reduced oscillatory bursting, respectively. We conclude that HCN channels are not directly modulated by trace metals and divalent cation chelators but are subject to modulation by different MS-related cytokines.
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Affiliation(s)
- Tengiz Oniani
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
| | - Laura Vinnenberg
- Department of Neurology with Institute of Translational Neurology, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany; (L.V.); (P.H.)
| | - Rahul Chaudhary
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
| | - Julian A. Schreiber
- Institute of Pharmaceutical and Medicinal Chemistry, Westfälische Wilhelms-Universität, Corren-Str. 48, D-48149 Münster, Germany;
- Cellular Electrophysiology and Molecular Biology, Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Robert-Koch-Str. 45, D-48149 Münster, Germany;
| | - Kathrin Riske
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-Universität, Waldeyer-Str. 15, D-48149 Münster, Germany; (K.R.); (A.J.)
| | - Brandon Williams
- Center for Systems Neuroscience, Neurophotonics Center, Department of Biomedical Engineering, Boston University, 610 Commonwealth Ave., Boston, MA 02215, USA; (B.W.); (J.A.W.)
| | - Hans-Christian Pape
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
| | - John A. White
- Center for Systems Neuroscience, Neurophotonics Center, Department of Biomedical Engineering, Boston University, 610 Commonwealth Ave., Boston, MA 02215, USA; (B.W.); (J.A.W.)
| | - Anna Junker
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-Universität, Waldeyer-Str. 15, D-48149 Münster, Germany; (K.R.); (A.J.)
| | - Guiscard Seebohm
- Cellular Electrophysiology and Molecular Biology, Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Robert-Koch-Str. 45, D-48149 Münster, Germany;
| | - Sven G. Meuth
- Neurology Clinic, University Clinic Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany;
| | - Petra Hundehege
- Department of Neurology with Institute of Translational Neurology, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany; (L.V.); (P.H.)
| | - Thomas Budde
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
- Correspondence:
| | - Mehrnoush Zobeiri
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
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Riel EB, Jürs BC, Cordeiro S, Musinszki M, Schewe M, Baukrowitz T. The versatile regulation of K2P channels by polyanionic lipids of the phosphoinositide and fatty acid metabolism. J Gen Physiol 2022; 154:212926. [PMID: 34928298 PMCID: PMC8693234 DOI: 10.1085/jgp.202112989] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 12/01/2021] [Indexed: 12/29/2022] Open
Abstract
Work over the past three decades has greatly advanced our understanding of the regulation of Kir K+ channels by polyanionic lipids of the phosphoinositide (e.g., PIP2) and fatty acid metabolism (e.g., oleoyl-CoA). However, comparatively little is known regarding the regulation of the K2P channel family by phosphoinositides and by long-chain fatty acid–CoA esters, such as oleoyl-CoA. We screened 12 mammalian K2P channels and report effects of polyanionic lipids on all tested channels. We observed activation of members of the TREK, TALK, and THIK subfamilies, with the strongest activation by PIP2 for TRAAK and the strongest activation by oleoyl-CoA for TALK-2. By contrast, we observed inhibition for members of the TASK and TRESK subfamilies. Our results reveal that TASK-2 channels have both activatory and inhibitory PIP2 sites with different affinities. Finally, we provided evidence that PIP2 inhibition of TASK-1 and TASK-3 channels is mediated by closure of the recently identified lower X-gate as critical mutations within the gate (i.e., L244A, R245A) prevent PIP2-induced inhibition. Our findings establish that K+ channels of the K2P family are highly sensitive to polyanionic lipids, extending our knowledge of the mechanisms of lipid regulation and implicating the metabolism of these lipids as possible effector pathways to regulate K2P channel activity.
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Affiliation(s)
- Elena B Riel
- Institute of Physiology, Kiel University, Kiel, Germany
| | - Björn C Jürs
- Institute of Physiology, Kiel University, Kiel, Germany.,Medical School Hamburg, University of Applied Sciences and Medical University, Hamburg, Germany
| | | | | | - Marcus Schewe
- Institute of Physiology, Kiel University, Kiel, Germany
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Activity of TREK-2-like Channels in the Pyramidal Neurons of Rat Medial Prefrontal Cortex Depends on Cytoplasmic Calcium. BIOLOGY 2021; 10:biology10111119. [PMID: 34827112 PMCID: PMC8614805 DOI: 10.3390/biology10111119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/26/2021] [Accepted: 10/28/2021] [Indexed: 11/22/2022]
Abstract
Simple Summary The pyramidal neurons of rat prefrontal cortex express potassium channels identified as a non-canonical splice variant of the TREK-2 channel. The main function of TREK channels is to regulate the resting membrane potential. We showed that cytoplasmic Ca2+ upregulates the activity of TREK-2-like channels. Previous studies have indicated that the activation of TREK-2 channels is mediated by PI(4,5)P2, a polyanionic lipid in the inner leaflet of the plasma membrane. While TREK channels are believed to not be regulated by calcium, our work shows otherwise. We propose a model in which calcium ions enable the formation of PI(4,5)P2 nanoclusters, which stabilize active conformation of the channel. Abstract TREK-2-like channels in the pyramidal neurons of rat prefrontal cortex are characterized by a wide range of spontaneous activity—from very low to very high—independent of the membrane potential and the stimuli that are known to activate TREK-2 channels, such as temperature or membrane stretching. The aim of this study was to discover what factors are involved in high levels of TREK-2-like channel activity in these cells. Our research focused on the PI(4,5)P2-dependent mechanism of channel activity. Single-channel patch clamp recordings were performed on freshly dissociated pyramidal neurons of rat prefrontal cortexes in both the cell-attached and inside-out configurations. To evaluate the role of endogenous stimulants, the activity of the channels was recorded in the presence of a PI(4,5)P2 analogue (PI(4,5)P2DiC8) and Ca2+. Our research revealed that calcium ions are an important factor affecting TREK-2-like channel activity and kinetics. The observation that calcium participates in the activation of TREK-2-like channels is a new finding. We showed that PI(4,5)P2-dependent TREK-2 activity occurs when the conditions for PI(4,5)P2/Ca2+ nanocluster formation are met. We present a possible model explaining the mechanism of calcium action.
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Park S, Flüthmann P, Wolany C, Goedecke L, Spenner HM, Budde T, Pape HC, Jüngling K. Neuropeptide S Receptor Stimulation Excites Principal Neurons in Murine Basolateral Amygdala through a Calcium-Dependent Decrease in Membrane Potassium Conductance. Pharmaceuticals (Basel) 2021; 14:ph14060519. [PMID: 34072275 PMCID: PMC8230190 DOI: 10.3390/ph14060519] [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: 04/20/2021] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 02/08/2023] Open
Abstract
Background: The neuropeptide S system, consisting of the 20 amino acid neuropeptide NPS and its G-protein-coupled receptor (GPCR) neuropeptide S receptor 1 (NPSR1), has been studied intensively in rodents. Although there is a lot of data retrieved from behavioral studies using pharmacology or genetic interventions, little is known about intracellular signaling cascades in neurons endogenously expressing the NPSR1. Methods: To elucidate possible G-protein-dependent signaling and effector systems, we performed whole-cell patch-clamp recordings on principal neurons of the anterior basolateral amygdala of mice. We used pharmacological interventions to characterize the NPSR1-mediated current induced by NPS application. Results: Application of NPS reliably evokes inward-directed currents in amygdalar neurons recorded in brain slice preparations of male and female mice. The NPSR1-mediated current had a reversal potential near the potassium reversal potential (EK) and was accompanied by an increase in membrane input resistance. GDP-β-S and BAPTA, but neither adenylyl cyclase inhibition nor 8-Br-cAMP, abolished the current. Intracellular tetraethylammonium or 4-aminopyridine reduced the NPS-evoked current. Conclusion: NPSR1 activation in amygdalar neurons inhibits voltage-gated potassium (K+) channels, most likely members of the delayed rectifier family. Intracellularly, Gαq signaling and calcium ions seem to be mandatory for the observed current and increased neuronal excitability.
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O'Reilly C, Iavarone E, Yi J, Hill SL. Rodent somatosensory thalamocortical circuitry: Neurons, synapses, and connectivity. Neurosci Biobehav Rev 2021; 126:213-235. [PMID: 33766672 DOI: 10.1016/j.neubiorev.2021.03.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 02/15/2021] [Accepted: 03/14/2021] [Indexed: 01/21/2023]
Abstract
As our understanding of the thalamocortical system deepens, the questions we face become more complex. Their investigation requires the adoption of novel experimental approaches complemented with increasingly sophisticated computational modeling. In this review, we take stock of current data and knowledge about the circuitry of the somatosensory thalamocortical loop in rodents, discussing common principles across modalities and species whenever appropriate. We review the different levels of organization, including the cells, synapses, neuroanatomy, and network connectivity. We provide a complete overview of this system that should be accessible for newcomers to this field while nevertheless being comprehensive enough to serve as a reference for seasoned neuroscientists and computational modelers studying the thalamocortical system. We further highlight key gaps in data and knowledge that constitute pressing targets for future experimental work. Filling these gaps would provide invaluable information for systematically unveiling how this system supports behavioral and cognitive processes.
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Affiliation(s)
- Christian O'Reilly
- Azrieli Centre for Autism Research, Montreal Neurological Institute, McGill University, Montreal, Canada; Ronin Institute, Montclair, NJ, USA; Blue Brain Project, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland.
| | - Elisabetta Iavarone
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Jane Yi
- Brain Mind Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Sean L Hill
- Blue Brain Project, École Polytechnique Fédérale de Lausanne, Geneva, Switzerland; Department of Psychiatry, University of Toronto, Toronto, Canada; Centre for Addiction and Mental Health, Toronto, Canada.
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Herrmann AM, Cerina M, Bittner S, Meuth SG, Budde T. Intracellular fluoride influences TASK mediated currents in human T cells. J Immunol Methods 2020; 487:112875. [PMID: 33031794 DOI: 10.1016/j.jim.2020.112875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 08/14/2020] [Accepted: 10/01/2020] [Indexed: 10/23/2022]
Abstract
The expression of Kv1.3 and KCa channels in human T cells is essential for maintaining cell activation, proliferation and migration during an inflammatory response. Recently, an additional residual current, sensitive to anandamide and A293, compounds specifically inhibiting currents mediated by TASK channels, was observed after complete pharmacological blockade of Kv1.3 and KCa channels. This finding was not consistently observed throughout different studies and, an in-depth review of the different recording conditions used for the electrophysiological analysis of K+ currents in T cells revealed fluoride as major anionic component of the pipette intracellular solutions in the initial studies. While fluoride is frequently used to stabilize electrophysiological recordings, it is known as G-protein activator and to influence the intracellular Ca2+ concentration, which are mechanisms known to modulate TASK channel functioning. Therefore, we systemically addressed different fluoride- and chloride-based pipette solutions in whole-cell patch-clamp experiments in human T cells and used specific blockers to identify membrane currents carried by TASK and Kv1.3 channels. We found that fluoride increased the decay time constant of K+ outward currents, reduced the degree of the sustained current component and diminished the effect of the specific TASK channels blocker A293. These findings indicate that the use of fluoride-based pipette solutions may hinder the identification of a functional TASK channel component in electrophysiological experiments.
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Affiliation(s)
- Alexander M Herrmann
- Department of Neurology with Institute of Translational Neurology, Münster University Hospital, Münster, Germany.
| | - Manuela Cerina
- Department of Neurology with Institute of Translational Neurology, Münster University Hospital, Münster, Germany
| | - Stefan Bittner
- Department of Neurology, University of Mainz, Mainz, Germany
| | - Sven G Meuth
- Department of Neurology with Institute of Translational Neurology, Münster University Hospital, Münster, Germany
| | - Thomas Budde
- Institute of Physiology I, Westfälische-Wilhems Universität Münster, Münster, Germany.
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12
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Gillet C, Kurth S, Kuenzel T. Muscarinic modulation of M and h currents in gerbil spherical bushy cells. PLoS One 2020; 15:e0226954. [PMID: 31940388 PMCID: PMC6961914 DOI: 10.1371/journal.pone.0226954] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 12/10/2019] [Indexed: 11/18/2022] Open
Abstract
Descending cholinergic fibers innervate the cochlear nucleus. Spherical bushy cells, principal neurons of the anterior part of the ventral cochlear nucleus, are depolarized by cholinergic agonists on two different time scales. A fast and transient response is mediated by alpha-7 homomeric nicotinic receptors while a slow and long-lasting response is mediated by muscarinic receptors. Spherical bushy cells were shown to express M3 receptors, but the receptor subtypes involved in the slow muscarinic response were not physiologically identified yet. Whole-cell patch clamp recordings combined with pharmacology and immunohistochemistry were performed to identify the muscarinic receptor subtypes and the effector currents involved. Spherical bushy cells also expressed both M1 and M2 receptors. The M1 signal was stronger and mainly somatic while the M2 signal was localized in the neuropil and on the soma of bushy cells. Physiologically, the M-current was observed for the gerbil spherical bushy cells and was inhibited by oxotremorine-M application. Surprisingly, long application of carbachol showed only a transient depolarization. Even though no muscarinic depolarization could be detected, the input resistance increased suggesting a decrease in the cell conductance that matched with the closure of M-channels. The hyperpolarization-activated currents were also affected by muscarinic activation and counteracted the effect of the inactivation of M-current on the membrane potential. We hypothesize that this double muscarinic action might allow adaptation of effects during long durations of cholinergic activation.
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Affiliation(s)
- Charlène Gillet
- Auditory Neurophysiology Group, Department of Chemosensation, RWTH Aachen University, Worringerweg, Aachen, Germany
| | - Stefanie Kurth
- Department of Chemosensation, RWTH Aachen University, Worringerweg, Aachen, Germany
| | - Thomas Kuenzel
- Auditory Neurophysiology Group, Department of Chemosensation, RWTH Aachen University, Worringerweg, Aachen, Germany
- Department of Chemosensation, RWTH Aachen University, Worringerweg, Aachen, Germany
- * E-mail:
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13
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Muscarinic receptor stimulation induces TASK1 channel endocytosis through a PKC-Pyk2-Src pathway in PC12 cells. Cell Signal 2020; 65:109434. [DOI: 10.1016/j.cellsig.2019.109434] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/01/2019] [Accepted: 10/01/2019] [Indexed: 11/21/2022]
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14
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TASK-3 Gene Knockdown Dampens Invasion and Migration and Promotes Apoptosis in KATO III and MKN-45 Human Gastric Adenocarcinoma Cell Lines. Int J Mol Sci 2019; 20:ijms20236077. [PMID: 31810225 PMCID: PMC6928893 DOI: 10.3390/ijms20236077] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 11/26/2019] [Accepted: 11/27/2019] [Indexed: 12/13/2022] Open
Abstract
Incidence and mortality of gastric cancer is increasing worldwide, in part, because of the lack of new therapeutic targets to treat this disease. Different types of ion channels participate in the hallmarks of cancer. In this context, ion channels are known to exert control over the cell cycle, mechanisms that support survival, angiogenesis, migration, and cell invasion. In particular, TASK-3 (KCNK9), a member of the K2P potassium channel family, has attracted much interest because of its oncogenic properties. However, despite multiple lines of evidence linking TASK-3 to tumorigenesis in various types of cancer, its relationship with gastric cancer has not been fully examined. Therefore, we set out to assess the effect of TASK-3 gene knockdown on KATO III and MKN-45 human gastric adenocarcinoma cell lines by using a short hairpin RNA (shRNA)-mediated knockdown. Our results demonstrate that knocking down TASK-3 reduces cell proliferation and viability because of an increase in apoptosis without an apparent effect on cell cycle checkpoints. In addition, cell migration and invasion are reduced after knocking down TASK-3 in these cell lines. The present study highlights TASK-3 as a key protein involved in migration and cell survival in gastric cancer and corroborates its potential as a therapeutic target for gastric cancer treatment.
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15
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Albrecht S, Korr S, Nowack L, Narayanan V, Starost L, Stortz F, Araúzo‐Bravo MJ, Meuth SG, Kuhlmann T, Hundehege P. The K
2P
‐channel TASK1 affects Oligodendroglial differentiation but not myelin restoration. Glia 2019; 67:870-883. [DOI: 10.1002/glia.23577] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/23/2018] [Accepted: 11/26/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Stefanie Albrecht
- Institute of NeuropathologyUniversity Hospital Münster Münster Germany
| | - Sabrina Korr
- Institute of NeuropathologyUniversity Hospital Münster Münster Germany
- Department of Neurology with Institute of Translational NeurologyUniversity Hospital Münster Münster Germany
- Cells in Motion, Cluster of Excellence Münster Germany
| | - Luise Nowack
- Institute of NeuropathologyUniversity Hospital Münster Münster Germany
- Department of Neurology with Institute of Translational NeurologyUniversity Hospital Münster Münster Germany
| | - Venu Narayanan
- Department of Neurology with Institute of Translational NeurologyUniversity Hospital Münster Münster Germany
| | - Laura Starost
- Institute of NeuropathologyUniversity Hospital Münster Münster Germany
| | - Franziska Stortz
- Institute of NeuropathologyUniversity Hospital Münster Münster Germany
| | - Marcos J. Araúzo‐Bravo
- Group of Computational Biology and Systems Biomedicine, Biodonostia Health Research Institute San Sebastian Spain
- IKERBASQUE, Basque Foundation for Science Bilbao Spain
| | - Sven G. Meuth
- Department of Neurology with Institute of Translational NeurologyUniversity Hospital Münster Münster Germany
- Cells in Motion, Cluster of Excellence Münster Germany
| | - Tanja Kuhlmann
- Institute of NeuropathologyUniversity Hospital Münster Münster Germany
| | - Petra Hundehege
- Department of Neurology with Institute of Translational NeurologyUniversity Hospital Münster Münster Germany
- Cells in Motion, Cluster of Excellence Münster Germany
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16
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Hackelberg S, Oliver D. Metabotropic Acetylcholine and Glutamate Receptors Mediate PI(4,5)P 2 Depletion and Oscillations in Hippocampal CA1 Pyramidal Neurons in situ. Sci Rep 2018; 8:12987. [PMID: 30154490 PMCID: PMC6113233 DOI: 10.1038/s41598-018-31322-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 08/17/2018] [Indexed: 01/24/2023] Open
Abstract
The sensitivity of many ion channels to phosphatidylinositol-4,5-bisphosphate (PIP2) levels in the cell membrane suggests that PIP2 fluctuations are important and general signals modulating neuronal excitability. Yet the PIP2 dynamics of central neurons in their native environment remained largely unexplored. Here, we examined the behavior of PIP2 concentrations in response to activation of Gq-coupled neurotransmitter receptors in rat CA1 hippocampal neurons in situ in acute brain slices. Confocal microscopy of the PIP2-selective molecular sensors tubbyCT-GFP and PLCδ1-PH-GFP showed that pharmacological activation of muscarinic acetylcholine (mAChR) or group I metabotropic glutamate (mGluRI) receptors induces transient depletion of PIP2 in the soma as well as in the dendritic tree. The observed PIP2 dynamics were receptor-specific, with mAChR activation inducing stronger PIP2 depletion than mGluRI, whereas agonists of other Gαq-coupled receptors expressed in CA1 neurons did not induce measureable PIP2 depletion. Furthermore, the data show for the first time neuronal receptor-induced oscillations of membrane PIP2 concentrations. Oscillatory behavior indicated that neurons can rapidly restore PIP2 levels during persistent activation of Gq and PLC. Electrophysiological responses to receptor activation resembled PIP2 dynamics in terms of time course and receptor specificity. Our findings support a physiological function of PIP2 in regulating electrical activity.
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Affiliation(s)
- Sandra Hackelberg
- Institute of Physiology and Pathophysiology, Philipps University, 35037, Marburg, Germany
- The Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Dominik Oliver
- Institute of Physiology and Pathophysiology, Philipps University, 35037, Marburg, Germany.
- DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling, GRK 2213, Philipps University, Marburg, Germany.
- Center for Mind, Brain and Behavior (CMBB), Marburg and Giessen, Germany.
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17
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Sonoda T, Lee SK, Birnbaumer L, Schmidt TM. Melanopsin Phototransduction Is Repurposed by ipRGC Subtypes to Shape the Function of Distinct Visual Circuits. Neuron 2018; 99:754-767.e4. [PMID: 30017393 PMCID: PMC6107377 DOI: 10.1016/j.neuron.2018.06.032] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 01/07/2018] [Accepted: 06/20/2018] [Indexed: 12/15/2022]
Abstract
Melanopsin is expressed in distinct types of intrinsically photosensitive retinal ganglion cells (ipRGCs), which drive behaviors from circadian photoentrainment to contrast detection. A major unanswered question is how the same photopigment, melanopsin, influences such vastly different functions. Here we show that melanopsin's role in contrast detection begins in the retina, via direct effects on M4 ipRGC (ON alpha RGC) signaling. This influence persists across an unexpectedly wide range of environmental light levels ranging from starlight to sunlight, which considerably expands the functional reach of melanopsin on visual processing. Moreover, melanopsin increases the excitability of M4 ipRGCs via closure of potassium leak channels, a previously unidentified target of the melanopsin phototransduction cascade. Strikingly, this mechanism is selective for image-forming circuits, as M1 ipRGCs (involved in non-image forming behaviors), exhibit a melanopsin-mediated decrease in excitability. Thus, melanopsin signaling is repurposed by ipRGC subtypes to shape distinct visual behaviors.
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Affiliation(s)
- Takuma Sonoda
- Department of Neurobiology, Northwestern University, Evanston, IL, USA; Northwestern University Interdepartmental Neuroscience Program, Northwestern University, Chicago, IL, USA
| | - Seul Ki Lee
- Department of Neurobiology, Northwestern University, Evanston, IL, USA
| | - Lutz Birnbaumer
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, USA; Institute of Biomedical Research (BIOMED), School of Medical Sciences, Catholic University of Argentina, Buenos Aires, Argentina
| | - Tiffany M Schmidt
- Department of Neurobiology, Northwestern University, Evanston, IL, USA.
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18
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Godazgar M, Zhang Q, Chibalina MV, Rorsman P. Biphasic voltage-dependent inactivation of human Na V 1.3, 1.6 and 1.7 Na + channels expressed in rodent insulin-secreting cells. J Physiol 2018; 596:1601-1626. [PMID: 29441586 PMCID: PMC5924821 DOI: 10.1113/jp275587] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/06/2018] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS Na+ current inactivation is biphasic in insulin-secreting cells, proceeding with two voltage dependences that are half-maximal at ∼-100 mV and -60 mV. Inactivation of voltage-gated Na+ (NaV ) channels occurs at ∼30 mV more negative voltages in insulin-secreting Ins1 and primary β-cells than in HEK, CHO or glucagon-secreting αTC1-6 cells. The difference in inactivation between Ins1 and non-β-cells persists in the inside-out patch configuration, discounting an involvement of a diffusible factor. In Ins1 cells and primary β-cells, but not in HEK cells, inactivation of a single NaV subtype is biphasic and follows two voltage dependences separated by 30-40 mV. We propose that NaV channels adopt different inactivation behaviours depending on the local membrane environment. ABSTRACT Pancreatic β-cells are equipped with voltage-gated Na+ channels that undergo biphasic voltage-dependent steady-state inactivation. A small Na+ current component (10-15%) inactivates over physiological membrane potentials and contributes to action potential firing. However, the major Na+ channel component is completely inactivated at -90 to -80 mV and is therefore inactive in the β-cell. It has been proposed that the biphasic inactivation reflects the contribution of different NaV α-subunits. We tested this possibility by expression of TTX-resistant variants of the NaV subunits found in β-cells (NaV 1.3, NaV 1.6 and NaV 1.7) in insulin-secreting Ins1 cells and in non-β-cells (including HEK and CHO cells). We found that all NaV subunits inactivated at 20-30 mV more negative membrane potentials in Ins1 cells than in HEK or CHO cells. The more negative inactivation in Ins1 cells does not involve a diffusible intracellular factor because the difference between Ins1 and CHO persisted after excision of the membrane. NaV 1.7 inactivated at 15--20 mV more negative membrane potentials than NaV 1.3 and NaV 1.6 in Ins1 cells but this small difference is insufficient to solely explain the biphasic inactivation in Ins1 cells. In Ins1 cells, but never in the other cell types, widely different components of NaV inactivation (separated by 30 mV) were also observed following expression of a single type of NaV α-subunit. The more positive component exhibited a voltage dependence of inactivation similar to that found in HEK and CHO cells. We propose that biphasic NaV inactivation in insulin-secreting cells reflects insertion of channels in membrane domains that differ with regard to lipid and/or membrane protein composition.
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Affiliation(s)
- Mahdieh Godazgar
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineUniversity of OxfordChurchill HospitalOxfordOX3 7LEUK
| | - Quan Zhang
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineUniversity of OxfordChurchill HospitalOxfordOX3 7LEUK
| | - Margarita V. Chibalina
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineUniversity of OxfordChurchill HospitalOxfordOX3 7LEUK
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of MedicineUniversity of OxfordChurchill HospitalOxfordOX3 7LEUK
- Metabolic PhysiologyDepartment of Neuroscience and PhysiologyMedicinaregatan 11GothenburgS‐413 09Sweden
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19
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Zobeiri M, Chaudhary R, Datunashvili M, Heuermann RJ, Lüttjohann A, Narayanan V, Balfanz S, Meuth P, Chetkovich DM, Pape HC, Baumann A, van Luijtelaar G, Budde T. Modulation of thalamocortical oscillations by TRIP8b, an auxiliary subunit for HCN channels. Brain Struct Funct 2018; 223:1537-1564. [PMID: 29168010 PMCID: PMC5869905 DOI: 10.1007/s00429-017-1559-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 10/30/2017] [Indexed: 12/16/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels have important functions in controlling neuronal excitability and generating rhythmic oscillatory activity. The role of tetratricopeptide repeat-containing Rab8b-interacting protein (TRIP8b) in regulation of hyperpolarization-activated inward current, I h, in the thalamocortical system and its functional relevance for the physiological thalamocortical oscillations were investigated. A significant decrease in I h current density, in both thalamocortical relay (TC) and cortical pyramidal neurons was found in TRIP8b-deficient mice (TRIP8b-/-). In addition basal cAMP levels in the brain were found to be decreased while the availability of the fast transient A-type K+ current, I A, in TC neurons was increased. These changes were associated with alterations in intrinsic properties and firing patterns of TC neurons, as well as intrathalamic and thalamocortical network oscillations, revealing a significant increase in slow oscillations in the delta frequency range (0.5-4 Hz) during episodes of active-wakefulness. In addition, absence of TRIP8b suppresses the normal desynchronization response of the EEG during the switch from slow-wave sleep to wakefulness. It is concluded that TRIP8b is necessary for the modulation of physiological thalamocortical oscillations due to its direct effect on HCN channel expression in thalamus and cortex and that mechanisms related to reduced cAMP signaling may contribute to the present findings.
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Affiliation(s)
- Mehrnoush Zobeiri
- Institut für Physiologie I, Westfälische Wilhelms-Universität, 48149, Münster, Germany.
| | - Rahul Chaudhary
- Institut für Physiologie I, Westfälische Wilhelms-Universität, 48149, Münster, Germany
| | - Maia Datunashvili
- Institut für Physiologie I, Westfälische Wilhelms-Universität, 48149, Münster, Germany
| | - Robert J Heuermann
- Davee Department of Neurology and Clinical Neurosciences and Department of Physiology, Feinberg School of Medicine, Northwestern University, 60611Chicago, USA
| | - Annika Lüttjohann
- Institut für Physiologie I, Westfälische Wilhelms-Universität, 48149, Münster, Germany
| | - Venu Narayanan
- Department of Neurology and Institute of Translational Neurology, Westfälische Wilhelms-Universität, 48149, Münster, Germany
| | - Sabine Balfanz
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Patrick Meuth
- Institut für Physiologie I, Westfälische Wilhelms-Universität, 48149, Münster, Germany
| | - Dane M Chetkovich
- Davee Department of Neurology and Clinical Neurosciences and Department of Physiology, Feinberg School of Medicine, Northwestern University, 60611Chicago, USA
| | - Hans-Christian Pape
- Institut für Physiologie I, Westfälische Wilhelms-Universität, 48149, Münster, Germany
| | - Arnd Baumann
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, 52425, Jülich, Germany
| | | | - Thomas Budde
- Institut für Physiologie I, Westfälische Wilhelms-Universität, 48149, Münster, Germany.
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20
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Brown DA. Regulation of neural ion channels by muscarinic receptors. Neuropharmacology 2017; 136:383-400. [PMID: 29154951 DOI: 10.1016/j.neuropharm.2017.11.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 10/26/2017] [Accepted: 11/13/2017] [Indexed: 12/20/2022]
Abstract
The excitable behaviour of neurons is determined by the activity of their endogenous membrane ion channels. Since muscarinic receptors are not themselves ion channels, the acute effects of muscarinic receptor stimulation on neuronal function are governed by the effects of the receptors on these endogenous neuronal ion channels. This review considers some principles and factors determining the interaction between subtypes and classes of muscarinic receptors with neuronal ion channels, and summarizes the effects of muscarinic receptor stimulation on a number of different channels, the mechanisms of receptor - channel transduction and their direct consequences for neuronal activity. Ion channels considered include potassium channels (voltage-gated, inward rectifier and calcium activated), voltage-gated calcium channels, cation channels and chloride channels. This article is part of the Special Issue entitled 'Neuropharmacology on Muscarinic Receptors'.
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Affiliation(s)
- David A Brown
- Department of Neuroscience, Physiology & Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
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21
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Affiliation(s)
- Donghee Kim
- Department of Physiology and Biophysics, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL, 60064, USA
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22
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Matsuoka H, Inoue M. Molecular mechanism for muscarinic M 1 receptor-mediated endocytosis of TWIK-related acid-sensitive K + 1 channels in rat adrenal medullary cells. J Physiol 2017; 595:6851-6867. [PMID: 28944482 DOI: 10.1113/jp275039] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 09/15/2017] [Indexed: 01/25/2023] Open
Abstract
KEY POINTS The muscarinic acetylcholine receptor (mAChR)-mediated increase in excitability in rat adrenal medullary cells is at least in part due to inhibition of TWIK (tandem of P domains in a weak inwardly rectifying K+ channel)-related acid-sensitive K+ (TASK)1 channels. In this study we focused on the molecular mechanism of mAChR-mediated inhibition of TASK1 channels. Exposure to muscarine resulted in a clathrin-dependent endocytosis of TASK1 channels following activation of the muscarinic M1 receptor (M1 R). This muscarinic signal for the endocytosis was mediated in sequence by phospholipase C (PLC), protein kinase C (PKC), and then the non-receptor tyrosine kinase Src with the consequent tyrosine phosphorylation of TASK1. The present results establish that TASK1 channels are tyrosine phosphorylated and internalized in a clathrin-dependent manner in response to M1 R stimulation and this translocation is at least in part responsible for muscarinic inhibition of TASK1 channels in rat AM cells. ABSTRACT Activation of muscarinic receptor (mAChR) in rat adrenal medullary (AM) cells induces depolarization through the inhibition of TWIK-related acid-sensitive K+ (TASK)1 channels. Here, pharmacological and immunological approaches were used to elucidate the molecular mechanism for this mAChR-mediated inhibition. TASK1-like immunoreactive (IR) material was mainly located at the cell periphery in dissociated rat AM cells, and its majority was internalized in response to muscarine. The muscarine-induced inward current and translocation of TASK1 were suppressed by dynasore, a dynamin inhibitor. The muscarinic translocation was suppressed by MT7, a specific M1 antagonist, and the dose-response curves for muscarinic agonist-induced translocation were similar to those for the muscarinic inhibition of TASK1 currents. The muscarine-induced inward current and/or translocation of TASK1 were suppressed by inhibitors for phospholipase C (PLC), protein kinase C (PKC), and/or Src. TASK1 channels in AM cells and PC12 cells were transiently associated with Src and were tyrosine phosphorylated in response to muscarinic stimulation. After internalization, TASK1 channels were quickly dephosphorylated even while they remained in the cytoplasm. The cytoplasmic TASK1-like IR material quickly recycled back to the cell periphery after muscarine stimulation for 0.5 min, but not 10 min. We conclude that M1 R stimulation results in internalization of TASK1 channels through the PLC-PKC-Src pathway with the consequent phosphorylation of tyrosine and that this M1 R-mediated internalization is at least in part responsible for muscarinic inhibition of TASK1 channels in rat AM cells.
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Affiliation(s)
- Hidetada Matsuoka
- Department of Cell and Systems Physiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, 807-8555, Japan
| | - Masumi Inoue
- Department of Cell and Systems Physiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu, 807-8555, Japan
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23
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Leist M, Rinné S, Datunashvili M, Aissaoui A, Pape HC, Decher N, Meuth SG, Budde T. Acetylcholine-dependent upregulation of TASK-1 channels in thalamic interneurons by a smooth muscle-like signalling pathway. J Physiol 2017; 595:5875-5893. [PMID: 28714121 DOI: 10.1113/jp274527] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/10/2017] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS The ascending brainstem transmitter acetylcholine depolarizes thalamocortical relay neurons while it induces hyperpolarization in local circuit inhibitory interneurons. Sustained K+ currents are modulated in thalamic neurons to control their activity modes; for the interneurons the molecular nature of the underlying ion channels is as yet unknown. Activation of TASK-1 K+ channels results in hyperpolarization of interneurons and suppression of their action potential firing. The modulation cascade involves a non-receptor tyrosine kinase, c-Src. The present study identifies a novel pathway for the activation of TASK-1 channels in CNS neurons that resembles cholinergic signalling and TASK-1 current modulation during hypoxia in smooth muscle cells. ABSTRACT The dorsal part of the lateral geniculate nucleus (dLGN) is the main thalamic site for state-dependent transmission of visual information. Non-retinal inputs from the ascending arousal system and inhibition provided by γ-aminobutyric acid (GABA)ergic local circuit interneurons (INs) control neuronal activity within the dLGN. In particular, acetylcholine (ACh) depolarizes thalamocortical relay neurons by inhibiting two-pore domain potassium (K2P ) channels. Conversely, ACh also hyperpolarizes INs via an as-yet-unknown mechanism. By using whole cell patch-clamp recordings in brain slices and appropriate pharmacological tools we here report that stimulation of type 2 muscarinic ACh receptors induces IN hyperpolarization by recruiting the G-protein βγ subunit (Gβγ), class-1A phosphatidylinositol-4,5-bisphosphate 3-kinase, and cellular and sarcoma (c-Src) tyrosine kinase, leading to activation of two-pore domain weakly inwardly rectifying K+ channel (TWIK)-related acid-sensitive K+ (TASK)-1 channels. The latter was confirmed by the use of TASK-1-deficient mice. Furthermore inhibition of phospholipase Cβ as well as an increase in the intracellular level of phosphatidylinositol-3,4,5-trisphosphate facilitated the muscarinic effect. Our results have uncovered a previously unknown role of c-Src tyrosine kinase in regulating IN function in the brain and identified a novel mechanism by which TASK-1 channels are activated in neurons.
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Affiliation(s)
- Michael Leist
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Susanne Rinné
- Institut für Physiologie und Pathophysiologie, AG Vegetative Physiologie, Philipps-Universität, Deutschhausstraße 1-2, D-35037, Marburg, Germany
| | - Maia Datunashvili
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Ania Aissaoui
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Hans-Christian Pape
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
| | - Niels Decher
- Institut für Physiologie und Pathophysiologie, AG Vegetative Physiologie, Philipps-Universität, Deutschhausstraße 1-2, D-35037, Marburg, Germany
| | - Sven G Meuth
- Department of Neurology, Westfälische Wilhelms-Universität, Albert-Schweitzer-Campus 1, D-48149, Münster, Germany
| | - Thomas Budde
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149, Münster, Germany
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24
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Woo J, Shin DH, Kim HJ, Yoo HY, Zhang YH, Nam JH, Kim WK, Kim SJ. Inhibition of TREK-2 K(+) channels by PI(4,5)P2: an intrinsic mode of regulation by intracellular ATP via phosphatidylinositol kinase. Pflugers Arch 2016; 468:1389-402. [PMID: 27283411 DOI: 10.1007/s00424-016-1847-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 05/28/2016] [Accepted: 05/30/2016] [Indexed: 11/28/2022]
Abstract
TWIK-related two-pore domain K(+) channels 1 and 2 (TREKs) are activated under various physicochemical conditions. However, the directions in which they are regulated by PI(4,5)P2 and intracellular ATP are not clearly presented yet. In this study, we investigated the effects of ATP and PI(4,5)P2 on overexpressed TREKs (HEK293T and COS-7) and endogenously expressed TREK-2 (mouse astrocytes and WEHI-231 B cells). In all of these cells, both TREK-1 and TREK-2 currents were spontaneously increased by dialysis with ATP-free pipette solution for whole-cell recording (ITREK-1,w-c and ITREK-2w-c) or by membrane excision for inside-out patch clamping without ATP (ITREK-1,i-o and ITREK-2,i-o). Steady state ITREK-2,i-o was reversibly decreased by 3 mM ATP applied to the cytoplasmic side, and this reduction was prevented by wortmannin, a PI-kinase inhibitor. An exogenous application of PI(4,5)P2 inhibited the spontaneously increased ITREKs,i-o, suggesting that intrinsic PI(4,5)P2 maintained by intracellular ATP and PI kinase may set the basal activity of TREKs in the intact cells. The inhibition of intrinsic TREK-2 by ATP was more prominent in WEHI-231 cells than astrocytes. Interestingly, unspecific screening of negative charges by poly-L-lysine also inhibited ITREK-2,i-o. Application of PI(4,5)P2 after the poly-L-lysine treatment showed dose-dependent dual effects, initial activation and subsequent inhibition of ITREK-2,i-o at low and high concentrations, respectively. In HEK293T cells coexpressing TREK-2 and a voltage-sensitive PI(4,5)P2 phosphatase, sustained depolarization increased ITREK-2,w-c initially (<5 s) but then decreased the current below the control level. In HEK293T cells coexpressing TREK-2 and type 3 muscarinic receptor, application of carbachol induced transient activation and sustained suppression of ITREK-2,w-c and cell-attached ITREK-2. The inhibition of TREK-2 by unspecific electrostatic quenching, extensive dephosphorylation, or sustained hydrolysis of PI(4,5)P2 suggests the existence of dual regulatory modes that depend on PI(4,5)P2 concentration.
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Affiliation(s)
- Joohan Woo
- Department of Physiology, College of Medicine, Seoul National University, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, South Korea
| | - Dong Hoon Shin
- Division of Natural Medical Sciences, College of Health Science, Chosun University, Gwang-Ju, 501-759, South Korea
| | - Hyun Jong Kim
- Department of Physiology and Ion Channel Disease Research Center, College of Medicine, Dongguk University, Kyungju, 780-714, South Korea
| | - Hae Young Yoo
- Chung-Ang University Red Cross College of Nursing, Seoul, 100-031, South Korea
| | - Yin-Hua Zhang
- Department of Physiology, College of Medicine, Seoul National University, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, South Korea
| | - Joo Hyun Nam
- Department of Physiology and Ion Channel Disease Research Center, College of Medicine, Dongguk University, Kyungju, 780-714, South Korea
| | - Woo Kyung Kim
- Department of Physiology and Ion Channel Disease Research Center, College of Medicine, Dongguk University, Kyungju, 780-714, South Korea
| | - Sung Joon Kim
- Department of Physiology, College of Medicine, Seoul National University, 103 Daehak-ro, Jongno-gu, Seoul, 110-799, South Korea.
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25
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Ehling P, Meuth P, Eichinger P, Herrmann AM, Bittner S, Pawlowski M, Pankratz S, Herty M, Budde T, Meuth SG. Human T cells in silico: Modelling their electrophysiological behaviour in health and disease. J Theor Biol 2016; 404:236-250. [PMID: 27288542 DOI: 10.1016/j.jtbi.2016.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/27/2016] [Accepted: 06/01/2016] [Indexed: 01/27/2023]
Abstract
Although various types of ion channels are known to have an impact on human T cell effector functions, their exact mechanisms of influence are still poorly understood. The patch clamp technique is a well-established method for the investigation of ion channels in neurons and T cells. However, small cell sizes and limited selectivity of pharmacological blockers restrict the value of this experimental approach. Building a realistic T cell computer model therefore can help to overcome these kinds of limitations as well as reduce the overall experimental effort. The computer model introduced here was fed off ion channel parameters from literature and new experimental data. It is capable of simulating the electrophysiological behaviour of resting and activated human CD4(+) T cells under basal conditions and during extracellular acidification. The latter allows for the very first time to assess the electrophysiological consequences of tissue acidosis accompanying most forms of inflammation.
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Affiliation(s)
- Petra Ehling
- Department of Neurology, and Institute of Translational Neurology, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Münster, Germany.
| | - Patrick Meuth
- Department of Neurology, and Institute of Translational Neurology, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Münster, Germany
| | - Paul Eichinger
- Department of Neurology, and Institute of Translational Neurology, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Münster, Germany; Department of Neuroradiology, Klinikum rechts der Isar, Technische Universität München TUM, Ismaninger Strasse 22, 81675 Munich, Germany
| | - Alexander M Herrmann
- Department of Neurology, and Institute of Translational Neurology, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Münster, Germany
| | - Stefan Bittner
- Department of Neurology, University Medical Center of the Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Matthias Pawlowski
- Department of Neurology, and Institute of Translational Neurology, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Münster, Germany; Wellcome Trust and MRC Cambridge Stem Cell Institute, and Anne McLaren Laboratory for Regenerative Medicine, University of Cambridge, West Forvie Building, Forvie Site, Robinson Way, Cambridge, UK
| | - Susann Pankratz
- Department of Neurology, and Institute of Translational Neurology, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Münster, Germany
| | - Michael Herty
- RWTH Aachen University, Mathematics (Continuous optimization), Templergraben 55, 52056 Aachen, Germany
| | - Thomas Budde
- Institute of Physiology I, Westfälische Wilhelms-Universität Münster, Robert-Koch-Str. 27a, 48149 Münster, Germany
| | - Sven G Meuth
- Department of Neurology, and Institute of Translational Neurology, Westfälische Wilhelms-Universität Münster, Albert-Schweitzer-Campus 1, Building A1, 48149 Münster, Germany
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26
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Villalpando-Vargas F, Medina-Ceja L. Sparteine as an anticonvulsant drug: Evidence and possible mechanism of action. Seizure 2016; 39:49-55. [PMID: 27262285 DOI: 10.1016/j.seizure.2016.05.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 05/12/2016] [Accepted: 05/18/2016] [Indexed: 10/21/2022] Open
Abstract
Sparteine is a quinolizidine alkaloid extracted from Lupinus that has numerous pharmacological properties both in humans and animal models. In the central nervous system, sparteine reduces locomotor activity, has light analgesic effects, also has no effects on short-term memory or spatial learning and does not induce changes in behavior or electroencephalographic (EEG) activity. However, the anticonvulsant profile of sparteine is not fully characterized in experimental animals and there are no data in humans. Therefore, the present review focuses on the experimental evidence supporting the anticonvulsant action of sparteine in models of acute seizures and status epilepticus (SE), as well as its possible mechanisms of action. The evidence that supports the anticonvulsant effect of (-)-Sparteine sulfate includes the inhibition of seizures induced by maximal electro-stimulation, a delay in the onset of convulsive behavior and the prolongation of survival time in mice treated with pentylenetetrazole (PTZ). Additionally, sparteine delays the onset of convulsive behavior and decreases the severity and mortality of rats treated with PTZ and pilocarpine. Sparteine decreases amplitude and frequency or blocks the epileptiform activity induced by PTZ, pilocarpine and kainic acid. Sparteine may decrease hyperexcitability through the activation of the M2 and M4 subtypes of mAChRs, which is a probable mechanism of action that together with its systemic effects may favor its anticonvulsant effects against seizures and SE.
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Affiliation(s)
- Fridha Villalpando-Vargas
- Laboratory of Neurophysiology and Neurochemistry, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Jalisco, Mexico
| | - Laura Medina-Ceja
- Laboratory of Neurophysiology and Neurochemistry, Department of Cellular and Molecular Biology, CUCBA, University of Guadalajara, Jalisco, Mexico.
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27
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Leist M, Datunashvilli M, Kanyshkova T, Zobeiri M, Aissaoui A, Cerina M, Romanelli MN, Pape HC, Budde T. Two types of interneurons in the mouse lateral geniculate nucleus are characterized by different h-current density. Sci Rep 2016; 6:24904. [PMID: 27121468 PMCID: PMC4848471 DOI: 10.1038/srep24904] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 04/06/2016] [Indexed: 12/27/2022] Open
Abstract
Although hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels and the corresponding h-current (Ih) have been shown to fundamentally shape the activity pattern in the thalamocortical network, little is known about their function in local circuit GABAergic interneurons (IN) of the dorsal part of the lateral geniculate nucleus (dLGN). By combining electrophysiological, molecular biological, immunohistochemical and cluster analysis, we characterized the properties of Ih and the expression profile of HCN channels in IN. Passive and active electrophysiological properties of IN differed. Two subclasses of IN were resolved by unsupervised cluster analysis. Small cells were characterized by depolarized resting membrane potentials (RMP), stronger anomalous rectification, higher firing frequency of faster action potentials (APs), appearance of rebound bursting, and higher Ih current density compared to the large IN. The depolarization exerted by sustained HCN channel activity facilitated neuronal firing. In addition to cyclic nucleotides, Ih in IN was modulated by PIP2 probably based on the abundant expression of the HCN3 isoform. Furthermore, only IN with larger cell diameters expressed neuronal nitric oxide synthase (nNOS). It is discussed that Ih in IN is modulated by neurotransmitters present in the thalamus and that the specific properties of Ih in these cells closely reflect their modulatory options.
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Affiliation(s)
- Michael Leist
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany
| | - Maia Datunashvilli
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany.,Laboratory of Sleep-Wakefulness Cycle Studies, Faculty of Arts and Science, Ilia State University, Kakutsa Cholokashvili Ave 3/5, Tbilisi 0162, Georgia
| | - Tatyana Kanyshkova
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany
| | - Mehrnoush Zobeiri
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany
| | - Ania Aissaoui
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany
| | - Manuela Cerina
- Institut für Physiologie I - Neuropathophysiologie, Albert-Schweitzer Campus 1, 48149 Münster, Germany
| | - Maria Novella Romanelli
- Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, Via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy
| | - Hans-Christian Pape
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany
| | - Thomas Budde
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149 Münster, Germany
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28
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Villalpando-Vargas F, Medina-Ceja L. Effect of sparteine on status epilepticus induced in rats by pentylenetetrazole, pilocarpine and kainic acid. Brain Res 2015. [DOI: 10.1016/j.brainres.2015.07.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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29
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Kollert S, Dombert B, Döring F, Wischmeyer E. Activation of TRESK channels by the inflammatory mediator lysophosphatidic acid balances nociceptive signalling. Sci Rep 2015. [PMID: 26224542 PMCID: PMC4519772 DOI: 10.1038/srep12548] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
In dorsal root ganglia (DRG) neurons TRESK channels constitute a major current component of the standing outward current IKSO. A prominent physiological role of TRESK has been attributed to pain sensation. During inflammation mediators of pain e.g. lysophosphatidic acid (LPA) are released and modulate nociception. We demonstrate co-expression of TRESK and LPA receptors in DRG neurons. Heterologous expression of TRESK and LPA receptors in Xenopus oocytes revealed augmentation of basal K+ currents upon LPA application. In DRG neurons nociception can result from TRPV1 activation by capsaicin or LPA. Upon co-expression in Xenopus oocytes LPA simultaneously increased both depolarising TRPV1 and hyperpolarising TRESK currents. Patch-clamp recordings in cultured DRG neurons from TRESK[wt] mice displayed increased IKSO after application of LPA whereas under these conditions IKSO in neurons from TRESK[ko] mice remained unaltered. Under current-clamp conditions LPA application differentially modulated excitability in these genotypes upon depolarising pulses. Spike frequency was attenuated in TRESK[wt] neurons and, in contrast, augmented in TRESK[ko] neurons. Accordingly, excitation of nociceptive neurons by LPA is balanced by co-activation of TRESK channels. Hence excitation of sensory neurons is strongly controlled by the activity of TRESK channels, which therefore are good candidates for the treatment of pain disorders.
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Affiliation(s)
- Sina Kollert
- Institute of Physiology, AG Molecular Electrophysiology, University of Würzburg, 97070 Würzburg Germany
| | - Benjamin Dombert
- Institute for Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Frank Döring
- Institute of Physiology, AG Molecular Electrophysiology, University of Würzburg, 97070 Würzburg Germany
| | - Erhard Wischmeyer
- Institute of Physiology, AG Molecular Electrophysiology, University of Würzburg, 97070 Würzburg Germany
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30
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Phosphoinositide dynamics in the postsynaptic membrane compartment: Mechanisms and experimental approach. Eur J Cell Biol 2015; 94:401-14. [DOI: 10.1016/j.ejcb.2015.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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31
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Ehling P, Bittner S, Meuth SG, Budde T. TASK, TREK & Co.: a mutable potassium channel family for diverse tasks in the brain. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s13295-015-0007-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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32
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Rivas-Ramírez P, Cadaveira-Mosquera A, Lamas JA, Reboreda A. Muscarinic modulation of TREK currents in mouse sympathetic superior cervical ganglion neurons. Eur J Neurosci 2015; 42:1797-807. [PMID: 25899939 DOI: 10.1111/ejn.12930] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 03/30/2015] [Accepted: 04/20/2015] [Indexed: 01/05/2023]
Abstract
Muscarinic receptors play a key role in the control of neurotransmission in the autonomic ganglia, which has mainly been ascribed to the regulation of potassium M-currents and voltage-dependent calcium currents. Muscarinic agonists provoke depolarization of the membrane potential and a reduction in spike frequency adaptation in postganglionic neurons, effects that may be explained by M-current inhibition. Here, we report the presence of a riluzole-activated current (IRIL ) that flows through the TREK-2 channels, and that is also inhibited by muscarinic agonists in neurons of the mouse superior cervical ganglion (mSCG). The muscarinic agonist oxotremorine-M (Oxo-M) inhibited the IRIL by 50%, an effect that was abolished by pretreatment with atropine or pirenzepine, but was unaffected in the presence of himbacine. Moreover, these antagonists had similar effects on single-channel TREK-2 currents. IRIL inhibition was unaffected by pretreatment with pertussis toxin. The protein kinase C blocker bisindolylmaleimide did not have an effect, and neither did the inositol triphosphate antagonist 2-aminoethoxydiphenylborane. Nevertheless, the IRIL was markedly attenuated by the phospholipase C (PLC) inhibitor ET-18-OCH3. Finally, the phosphatidylinositol-3-kinase/phosphatidylinositol-4-kinase inhibitor wortmannin strongly attenuated the IRIL , whereas blocking phosphatidylinositol 4,5-bisphosphate (PIP2 ) depletion consistently prevented IRIL inhibition by Oxo-M. These results demonstrate that TREK-2 currents in mSCG neurons are inhibited by muscarinic agonists that activate M1 muscarinic receptors, reducing PIP2 levels via a PLC-dependent pathway. The similarities between the signaling pathways regulating the IRIL and the M-current in the same neurons reflect an important role of this new pathway in the control of autonomic ganglia excitability.
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Affiliation(s)
- P Rivas-Ramírez
- Department of Functional Biology and Health Sciences, Faculty of Biology - CINBIO-IBIV, University of Vigo, Campus Lagoas-Marcosende, 36310, Vigo, Spain
| | - A Cadaveira-Mosquera
- Department of Functional Biology and Health Sciences, Faculty of Biology - CINBIO-IBIV, University of Vigo, Campus Lagoas-Marcosende, 36310, Vigo, Spain
| | - J A Lamas
- Department of Functional Biology and Health Sciences, Faculty of Biology - CINBIO-IBIV, University of Vigo, Campus Lagoas-Marcosende, 36310, Vigo, Spain
| | - A Reboreda
- Department of Functional Biology and Health Sciences, Faculty of Biology - CINBIO-IBIV, University of Vigo, Campus Lagoas-Marcosende, 36310, Vigo, Spain
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33
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Cerina M, Szkudlarek HJ, Coulon P, Meuth P, Kanyshkova T, Nguyen XV, Göbel K, Seidenbecher T, Meuth SG, Pape HC, Budde T. Thalamic Kv 7 channels: pharmacological properties and activity control during noxious signal processing. Br J Pharmacol 2015; 172:3126-40. [PMID: 25684311 DOI: 10.1111/bph.13113] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 01/27/2015] [Accepted: 02/10/2015] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND PURPOSE The existence of functional K(v)7 channels in thalamocortical (TC) relay neurons and the effects of the K(+)-current termed M-current (I(M)) on thalamic signal processing have long been debated. Immunocytochemical evidence suggests their presence in this brain region. Therefore, we aimed to verify their existence, pharmacological properties and function in regulating activity in neurons of the ventrobasal thalamus (VB). EXPERIMENTAL APPROACH Characterization of K(v)7 channels was performed by combining in vitro, in vivo and in silico techniques with a pharmacological approach. Retigabine (30 μM) and XE991 (20 μM), a specific K(v)7 channel enhancer and blocker, respectively, were applied in acute brain slices during electrophysiological recordings. The effects of intrathalamic injection of retigabine (3 mM, 300 nL) and/or XE991 (2 mM, 300 nL) were investigated in freely moving animals during hot-plate tests by recording behaviour and neuronal activity. KEY RESULTS K(v)7.2 and K(v)7.3 subunits were found to be abundantly expressed in TC neurons of mouse VB. A slow K(+)-current with properties of IM was activated by retigabine and inhibited by XE991. K(v)7 channel activation evoked membrane hyperpolarization, a reduction in tonic action potential firing, and increased burst firing in vitro and in computational models. Single-unit recordings and pharmacological intervention demonstrated a specific burst-firing increase upon I(M) activation in vivo. A K(v)7 channel-mediated increase in pain threshold was associated with fewer VB units responding to noxious stimuli, and increased burst firing in responsive neurons. CONCLUSIONS AND IMPLICATIONS K(v)7 channel enhancement alters somatosensory activity and may reflect an anti-nociceptive mechanism during acute pain processing.
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Affiliation(s)
- Manuela Cerina
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
| | - Hanna J Szkudlarek
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
| | - Philippe Coulon
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
| | - Patrick Meuth
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany.,Department of Neurology, Westfälische Wilhelms-University, Münster, Germany
| | - Tatyana Kanyshkova
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
| | - Xuan Vinh Nguyen
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
| | - Kerstin Göbel
- Department of Neurology, Westfälische Wilhelms-University, Münster, Germany
| | - Thomas Seidenbecher
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
| | - Sven G Meuth
- Department of Neurology, Westfälische Wilhelms-University, Münster, Germany.,Institute of Physiology-Neuropathophysiology, Westfälische Wilhelms-University, Münster, Germany
| | - Hans-Christian Pape
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
| | - Thomas Budde
- Institute of Physiology I, Westfälische Wilhelms-University, Münster, Germany
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34
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Renigunta V, Schlichthörl G, Daut J. Much more than a leak: structure and function of K₂p-channels. Pflugers Arch 2015; 467:867-94. [PMID: 25791628 DOI: 10.1007/s00424-015-1703-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 03/09/2015] [Indexed: 11/27/2022]
Abstract
Over the last decade, we have seen an enormous increase in the number of experimental studies on two-pore-domain potassium channels (K2P-channels). The collection of reviews and original articles compiled for this special issue of Pflügers Archiv aims to give an up-to-date summary of what is known about the physiology and pathophysiology of K2P-channels. This introductory overview briefly describes the structure of K2P-channels and their function in different organs. Its main aim is to provide some background information for the 19 reviews and original articles of this special issue of Pflügers Archiv. It is not intended to be a comprehensive review; instead, this introductory overview focuses on some unresolved questions and controversial issues, such as: Do K2P-channels display voltage-dependent gating? Do K2P-channels contribute to the generation of action potentials? What is the functional role of alternative translation initiation? Do K2P-channels have one or two or more gates? We come to the conclusion that we are just beginning to understand the extremely complex regulation of these fascinating channels, which are often inadequately described as 'leak channels'.
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Affiliation(s)
- Vijay Renigunta
- Institute of Physiology and Pathophysiology, Marburg University, 35037, Marburg, Germany
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35
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Ehling P, Cerina M, Budde T, Meuth SG, Bittner S. The CNS under pathophysiologic attack--examining the role of K₂p channels. Pflugers Arch 2014; 467:959-72. [PMID: 25482672 DOI: 10.1007/s00424-014-1664-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 11/17/2014] [Accepted: 11/28/2014] [Indexed: 10/24/2022]
Abstract
Members of the two-pore domain K(+) channel (K2P) family are increasingly recognized as being potential targets for therapeutic drugs and could play a role in the diagnosis and treatment of neurologic disorders. Their broad and diverse expression pattern in pleiotropic cell types, importance in cellular function, unique biophysical properties, and sensitivity toward pathophysiologic parameters represent the basis for their involvement in disorders of the central nervous system (CNS). This review will focus on multiple sclerosis (MS) and stroke, as there is growing evidence for the involvement of K2P channels in these two major CNS disorders. In MS, TASK1-3 channels are expressed on T lymphocytes and are part of a signaling network regulating Ca(2+)- dependent pathways that are mandatory for T cell activation, differentiation, and effector functions. In addition, TASK1 channels are involved in neurodegeneration, resulting in autoimmune attack of CNS cells. On the blood-brain barrier, TREK1 channels regulate immune cell trafficking under autoinflammatory conditions. Cerebral ischemia shares some pathophysiologic similarities with MS, including hypoxia and extracellular acidosis. On a cellular level, K2P channels can have both proapoptotic and antiapoptotic effects, either promoting neurodegeneration or protecting neurons from ischemic cell death. TASK1 and TREK1 channels have a neuroprotective effect on stroke development, whereas TASK2 channels have a detrimental effect on neuronal survival under ischemic conditions. Future research in preclinical models is needed to provide a more detailed understanding of the contribution of K2P channel family members to neurologic disorders, before translation to the clinic is an option.
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Affiliation(s)
- Petra Ehling
- Department of Neurology, University of Münster, Münster, Germany,
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36
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Bista P, Cerina M, Ehling P, Leist M, Pape HC, Meuth SG, Budde T. The role of two-pore-domain background K⁺ (K₂p) channels in the thalamus. Pflugers Arch 2014; 467:895-905. [PMID: 25346156 DOI: 10.1007/s00424-014-1632-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 10/09/2014] [Accepted: 10/12/2014] [Indexed: 12/15/2022]
Abstract
The thalamocortical system is characterized by two fundamentally different activity states, namely synchronized burst firing and tonic action potential generation, which mainly occur during the behavioral states of sleep and wakefulness, respectively. The switch between the two firing modes is crucially governed by the bidirectional modulation of members of the K2P channel family, namely tandem of P domains in a weakly inward rectifying K(+) (TWIK)-related acid-sensitive K(+) (TASK) and TWIK-related K(+) (TREK) channels, in thalamocortical relay (TC) neurons. Several physicochemical stimuli including neurotransmitters, protons, di- and multivalent cations as well as clinically used drugs have been shown to modulate K2P channels in these cells. With respect to modulation of these channels by G-protein-coupled receptors, PLCβ plays a unique role with both substrate breakdown and product synthesis exerting important functions. While the degradation of PIP2 leads to the closure of TREK channels, the production of DAG induces the inhibition of TASK channels. Therefore, TASK and TREK channels were found to be central elements in the control of thalamic activity modes. Since research has yet focused on identifying the muscarinic pathway underling the modulation of TASK and TREK channels in TC neurons, future studies should address other thalamic cell types and members of the K2P channel family.
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Affiliation(s)
- Pawan Bista
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, 48149, Münster, Germany
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