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Zhang H, Jiao L, Yang S, Li H, Jiang X, Feng J, Zou S, Xu Q, Gu J, Wang X, Wei B. Brain-computer interfaces: the innovative key to unlocking neurological conditions. Int J Surg 2024; 110:5745-5762. [PMID: 39166947 PMCID: PMC11392146 DOI: 10.1097/js9.0000000000002022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Accepted: 07/30/2024] [Indexed: 08/23/2024]
Abstract
Neurological disorders such as Parkinson's disease, stroke, and spinal cord injury can pose significant threats to human mortality, morbidity, and functional independence. Brain-Computer Interface (BCI) technology, which facilitates direct communication between the brain and external devices, emerges as an innovative key to unlocking neurological conditions, demonstrating significant promise in this context. This comprehensive review uniquely synthesizes the latest advancements in BCI research across multiple neurological disorders, offering an interdisciplinary perspective on both clinical applications and emerging technologies. We explore the progress in BCI research and its applications in addressing various neurological conditions, with a particular focus on recent clinical studies and prospective developments. Initially, the review provides an up-to-date overview of BCI technology, encompassing its classification, operational principles, and prevalent paradigms. It then critically examines specific BCI applications in movement disorders, disorders of consciousness, cognitive and mental disorders, as well as sensory disorders, highlighting novel approaches and their potential impact on patient care. This review reveals emerging trends in BCI applications, such as the integration of artificial intelligence and the development of closed-loop systems, which represent significant advancements over previous technologies. The review concludes by discussing the prospects and directions of BCI technology, underscoring the need for interdisciplinary collaboration and ethical considerations. It emphasizes the importance of prioritizing bidirectional and high-performance BCIs, areas that have been underexplored in previous reviews. Additionally, we identify crucial gaps in current research, particularly in long-term clinical efficacy and the need for standardized protocols. The role of neurosurgery in spearheading the clinical translation of BCI research is highlighted. Our comprehensive analysis presents BCI technology as an innovative key to unlocking neurological disorders, offering a transformative approach to diagnosing, treating, and rehabilitating neurological conditions, with substantial potential to enhance patients' quality of life and advance the field of neurotechnology.
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Affiliation(s)
- Hongyu Zhang
- Department of Neurosurgery, The Fourth Affiliated Hospital of Harbin Medical University
- Harbin Medical University, Harbin
| | - Le Jiao
- Department of Neurosurgery, The First Hospital of Qiqihar, Qiqihar, Heilongjiang Province
| | | | | | | | - Jing Feng
- Department of Neurosurgery, The Fourth Affiliated Hospital of Harbin Medical University
- Harbin Medical University, Harbin
| | - Shuhuai Zou
- Department of Neurosurgery, The Fourth Affiliated Hospital of Harbin Medical University
- Harbin Medical University, Harbin
| | - Qiang Xu
- Department of Neurosurgery, The Fourth Affiliated Hospital of Harbin Medical University
- Harbin Medical University, Harbin
| | - Jianheng Gu
- Department of Neurosurgery, The Fourth Affiliated Hospital of Harbin Medical University
- Harbin Medical University, Harbin
| | - Xuefeng Wang
- Department of Neurosurgery, The Fourth Affiliated Hospital of Harbin Medical University
| | - Baojian Wei
- School of Nursing, Shandong First Medical University & Shandong Academy of Medical Sciences, Taian, Shandong, People's Republic of China
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2
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Salmanzadeh H, Halliwell RF. Antiseizure properties of fenamate NSAIDs determined in mature human stem-cell derived neuroglial circuits. Front Pharmacol 2024; 15:1385523. [PMID: 38828453 PMCID: PMC11141243 DOI: 10.3389/fphar.2024.1385523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 04/30/2024] [Indexed: 06/05/2024] Open
Abstract
Repeated and uncontrolled seizures in epilepsy result in brain cell loss and neural inflammation. Current anticonvulsants primarily target ion channels and receptors implicated in seizure activity. Identification of neurotherapeutics that can inhibit epileptiform activity and reduce inflammation in the brain may offer significant benefits in the long-term management of epilepsy. Fenamates are unique because they are both non-steroidal anti-inflammatory drugs (NSAIDs) and highly subunit selective modulators of GABAA receptors. In the current study we have investigated the hypothesis that fenamates have antiseizure properties using mature human stem cell-derived neuro-glia cell cultures, maintained in long-term culture, and previously shown to be sensitive to first, second and third generation antiepileptics. Mefenamic acid, flufenamic acid, meclofenamic acid, niflumic acid, and tolfenamic acid (each tested at 10-100 μM) attenuated 4-aminopyridine (4-AP, 100 μM) evoked epileptiform activity in a dose-dependent fashion. These actions were as effective diazepam (3-30 μM) and up to 200 times more potent than phenobarbital (300-1,000 μM). The low (micromolar) concentrations of fenamates that inhibited 4-AP evoked epileptiform activity correspond to those reported to potentiate GABAA receptor function. In contrast, the fenamates had no effect on neural spike amplitudes, indicating that their antiseizure actions did not result from inhibition of sodium-channels. The antiseizure actions of fenamates were also not replicated by either of the two non-fenamate NSAIDs, ibuprofen (10-100 μM) or indomethacin (10-100 μM), indicating that inhibition of cyclooxygenases is not the mechanism through which fenamates have anticonvulsant properties. This study therefore shows for the first time, using functionally mature human stem cell-derived neuroglial circuits, that fenamate NSAIDs have powerful antiseizure actions independent of, and in addition to their well-established anti-inflammatory properties, suggesting these drugs may provide a novel insight and new approach to the treatment of epilepsy in the future.
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Affiliation(s)
| | - Robert F. Halliwell
- Thomas J. Long School of Pharmacy, University of the Pacific, Stockton, CA, United States
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Anju K, Shoba G, Sumita A, Balakumaran MD, Vasanthi R, Kumaran R. Interaction of acridinedione dye with a globular protein in the presence of site selective and site specific binding drugs: Photophysical techniques assisted by molecular docking methods. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 258:119814. [PMID: 33932635 DOI: 10.1016/j.saa.2021.119814] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 04/08/2021] [Accepted: 04/08/2021] [Indexed: 06/12/2023]
Abstract
Photophysical investigations and molecular docking studies of photoinduced electron transfer (PET) based fluorophores of acridine family with a globular protein, Bovine Serum Albumin (BSA) bound to non-narcotic drugs like phenylbutazone (PB) and flufenamic acid (FA) were carried out in aqueous solution. PB and FA are site specific and site selective drugs, wherein PB predominantly binds at the site (I) whereas FA selectively orients towards site (II) of BSA. Acridinedione (AD) dyes, both resorcinol and dimedone based are hydrophobic in nature and exhibits a combination of both hydrophobic and hydrogen-bonding interactions that are based on the binding sites in BSA. The extent of displacement of AD from the binding sites of BSA by PB and FA are elucidated and established from variation in the fluorescence lifetime and relative amplitude distribution of free and dye bound in site (I) and site (II). The extent of binding affinity of PB-BSA and FA-BSA in the presence of AD is minimal when compared to other site I and II drugs. This is attributed to AD dye bound to several amino acid residues present in BSA such that the dye prefers multiple binding sites in BSA even in the presence of FA and PB. Further, the dye bound to several amino acid residues of BSA ascertains the combination of hydrogen-bonding, hydrophobic interactions, pi-pi and pi-alkyl interaction apart from the binding through sites (I) and (II) from molecular docking methods. The combination of fluorescence tools with molecular modelling techniques provides an excellent approach in determining the stability of these complexes containing competitive guest molecules in the presence of a fluorescence probe and the binding characteristics of dye in a micro heterogeneous environment.
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Affiliation(s)
- Krishnan Anju
- Department of Chemistry, D.G. Vaishnav College (Autonomous), 833, Gokul Bagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600106, Tamil Nadu, India
| | - Gunasekaran Shoba
- Department of Biotechnology, D.G. Vaishnav College (Autonomous) (Affiliated to University of Madras), 833, GokulBagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600106, Tamil Nadu, India
| | - Anupurath Sumita
- Department of Chemistry, Anna Adarsh College for Women, Anna Nagar, Chennai 600040, Tamil Nadu, India
| | - Manickam Dakshinamoorthi Balakumaran
- Department of Biotechnology, D.G. Vaishnav College (Autonomous) (Affiliated to University of Madras), 833, GokulBagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600106, Tamil Nadu, India
| | - Rajaraman Vasanthi
- Department of Chemistry, D.G. Vaishnav College (Autonomous), 833, Gokul Bagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600106, Tamil Nadu, India
| | - Rajendran Kumaran
- Department of Chemistry, D.G. Vaishnav College (Autonomous), 833, Gokul Bagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600106, Tamil Nadu, India.
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Hill J, Zawia NH. Fenamates as Potential Therapeutics for Neurodegenerative Disorders. Cells 2021; 10:702. [PMID: 33809987 PMCID: PMC8004804 DOI: 10.3390/cells10030702] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 03/17/2021] [Accepted: 03/19/2021] [Indexed: 11/16/2022] Open
Abstract
Neurodegenerative disorders are desperately lacking treatment options. It is imperative that drug repurposing be considered in the fight against neurodegenerative diseases. Fenamates have been studied for efficacy in treating several neurodegenerative diseases. The purpose of this review is to comprehensively present the past and current research on fenamates in the context of neurodegenerative diseases with a special emphasis on tolfenamic acid and Alzheimer's disease. Furthermore, this review discusses the major molecular pathways modulated by fenamates.
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Affiliation(s)
- Jaunetta Hill
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA;
| | - Nasser H. Zawia
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA;
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI 02881, USA
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA
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5
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Dimiza F, Hatzidimitriou AG, Sanakis Y, Papadopoulos AN, Psomas G. Trinuclear and tetranuclear iron(III) complexes with fenamates: Structure and biological profile. J Inorg Biochem 2021; 218:111410. [PMID: 33721718 DOI: 10.1016/j.jinorgbio.2021.111410] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 01/16/2023]
Abstract
The interaction of FeCl3 with the fenamate non-steroidal anti-inflammatory drugs has led to the formation and isolation of trinuclear iron(III) complexes, while in the presence of the nitrogen-donors 2,2'-bipyridine or pyridine tetranuclear iron(III) complexes were derived. The five resultant complexes were characterized by diverse techniques (including infrared, electronic and Mössbauer spectroscopy) and their crystal structures were determined by single-crystal X-ray crystallography. These complexes are the first structurally characterized Fe(III)-fenamato complexes. The complexes were evaluated for their ability to scavenge in vitro free radicals such as hydroxyl, 1,1-diphenyl-2-picrylhydrazyl and 2,2΄-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid). The in vitro binding affinity of the complexes to calf-thymus (CT) DNA was examined and their interaction with serum albumins was also investigated. In total, the complexes present promising activity against the radicals tested, and they may bind tightly to CT DNA possibly via intercalation and reversibly to serum albumins.
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Affiliation(s)
- Filitsa Dimiza
- Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
| | - Antonios G Hatzidimitriou
- Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
| | - Yiannis Sanakis
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", 15310 Ag. Paraskevi, Attiki, Greece
| | - Athanasios N Papadopoulos
- Department of Nutritional Sciences and Dietetics, International Hellenic University, Sindos, Thessaloniki, Greece
| | - George Psomas
- Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
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Buntschu S, Tscherter A, Heidemann M, Streit J. Critical Components for Spontaneous Activity and Rhythm Generation in Spinal Cord Circuits in Culture. Front Cell Neurosci 2020; 14:81. [PMID: 32410961 PMCID: PMC7198714 DOI: 10.3389/fncel.2020.00081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/19/2020] [Indexed: 11/23/2022] Open
Abstract
Neuronal excitability contributes to rhythm generation in central pattern generating networks (CPGs). In spinal cord CPGs, such intrinsic excitability partly relies on persistent sodium currents (INaP), whereas respiratory CPGs additionally depend on calcium-activated cation currents (ICAN). Here, we investigated the contributions of INaP and ICAN to spontaneous rhythm generation in neuronal networks of the spinal cord and whether they mainly involve Hb9 neurons. We used cultures of ventral and transverse slices from the E13-14 embryonic rodent lumbar spinal cord on multielectrode arrays (MEAs). All cultures showed spontaneous bursts of network activity. Blocking synaptic excitation with the AMPA receptor antagonist CNQX suppressed spontaneous network bursts and left asynchronous intrinsic activity at about 30% of the electrodes. Such intrinsic activity was completely blocked at all electrodes by both the INaP blocker riluzole as well as by the ICAN blocker flufenamic acid (FFA) and the more specific TRPM4 channel antagonist 9-phenanthrol. All three antagonists also suppressed spontaneous bursting completely and strongly reduced stimulus-evoked bursts. Also, FFA reduced repetitive spiking that was induced in single neurons by injection of depolarizing current pulses to few spikes. Other antagonists of unspecific cation currents or calcium currents had no suppressing effects on either intrinsic activity (gadolinium chloride) or spontaneous bursting (the TRPC channel antagonists clemizole and ML204 and the T channel antagonist TTA-P2). Combined patch-clamp and MEA recordings showed that Hb9 interneurons were activated by network bursts but could not initiate them. Together these findings suggest that both INaP through Na+-channels and ICAN through putative TRPM4 channels contribute to spontaneous intrinsic and repetitive spiking in spinal cord neurons and thereby to the generation of network bursts.
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Affiliation(s)
| | | | | | - Jürg Streit
- Department of Physiology, University of Bern, Bern, Switzerland
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Inhibition of Fast Nerve Conduction Produced by Analgesics and Analgesic Adjuvants-Possible Involvement in Pain Alleviation. Pharmaceuticals (Basel) 2020; 13:ph13040062. [PMID: 32260535 PMCID: PMC7243109 DOI: 10.3390/ph13040062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/29/2020] [Accepted: 04/01/2020] [Indexed: 02/07/2023] Open
Abstract
Nociceptive information is transmitted from the periphery to the cerebral cortex mainly by action potential (AP) conduction in nerve fibers and chemical transmission at synapses. Although this nociceptive transmission is largely inhibited at synapses by analgesics and their adjuvants, it is possible that the antinociceptive drugs inhibit nerve AP conduction, contributing to their antinociceptive effects. Many of the drugs are reported to inhibit the nerve conduction of AP and voltage-gated Na+ and K+ channels involved in its production. Compound action potential (CAP) is a useful measure to know whether drugs act on nerve AP conduction. Clinically-used analgesics and analgesic adjuvants (opioids, non-steroidal anti-inflammatory drugs, 2-adrenoceptor agonists, antiepileptics, antidepressants and local anesthetics) were found to inhibit fast-conducting CAPs recorded from the frog sciatic nerve by using the air-gap method. Similar actions were produced by antinociceptive plant-derived chemicals. Their inhibitory actions depended on the concentrations and chemical structures of the drugs. This review article will mention the inhibitory actions of the antinociceptive compounds on CAPs in frog and mammalian peripheral (particularly, sciatic) nerves and on voltage-gated Na+ and K+ channels involved in AP production. Nerve AP conduction inhibition produced by analgesics and analgesic adjuvants is suggested to contribute to at least a part of their antinociceptive effects.
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Sun JF, Zhao MY, Xu YJ, Su Y, Kong XH, Wang ZY. Fenamates Inhibit Human Sodium Channel Nav1.2 and Protect Glutamate-Induced Injury in SH-SY5Y Cells. Cell Mol Neurobiol 2020; 40:1405-1416. [PMID: 32162200 DOI: 10.1007/s10571-020-00826-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/02/2020] [Indexed: 11/30/2022]
Abstract
Voltage-gated sodium channels are crucial mediators of neuronal damage in ischemic and excitotoxicity disease models. Fenamates have been reported to have anti-inflammatory properties following a decrease in prostaglandin synthesis. Several researches showed that fenamates appear to be ion channel modulators and potential neuroprotectants. In this study, the neuroprotective effects of tolfenamic acid, flufenamic acid, and mefenamic acid were tested by glutamate-induced injury in SH-SY5Y cells. Following this, fenamates' effects were examined on both the expression level and the function of hNav1.1 and hNav1.2, which were closely associated with neuroprotection, using Western blot and patch clamp. Finally, the effect of fenamates on the expression of apoptosis-related proteins in SH-SY5Y cells was examined. The results showed that both flufenamic acid and mefenamic acid exhibited neuroprotective effects against glutamate-induced injury in SH-SY5Y cells. They inhibited peak currents of both hNav1.1 and hNav1.2. However, fenamates exhibited decreased inhibitory effects on hNav1.1 when compared to hNav1.2. Correspondingly, the inhibitory effect of fenamates was found to be consistent with the level of neuroprotective effects in vitro. Fenamates inhibited glutamate-induced apoptosis through the modulation of the Bcl-2/Bax-dependent cell death pathways. Taken together, Nav1.2 might play a part in fenamates' neuroprotection mechanism. Nav1.2 and NMDAR might take part in the neuroprotection mechanism of the fenamates. The fenamates inhibited glutamate-induced apoptosis through modulation of the Bcl-2/Bax-dependent cell death pathways.
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Affiliation(s)
- Jian-Fang Sun
- College of Life and Health Sciences, Northeastern University, Shenyang, 110169, People's Republic of China
| | - Ming-Yi Zhao
- School of Life Sciences and Biopharmaceutical Science, Shenyang Pharmaceutical University, Shenyang, 110016, People's Republic of China
| | - Yi-Jia Xu
- School of Life Sciences and Biopharmaceutical Science, Shenyang Pharmaceutical University, Shenyang, 110016, People's Republic of China.
| | - Yang Su
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, 110004, People's Republic of China
| | - Xiao-Hua Kong
- School of Life Sciences and Biopharmaceutical Science, Shenyang Pharmaceutical University, Shenyang, 110016, People's Republic of China
| | - Zhan-You Wang
- College of Life and Health Sciences, Northeastern University, Shenyang, 110169, People's Republic of China.
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Involvement of TRPC4 and 5 Channels in Persistent Firing in Hippocampal CA1 Pyramidal Cells. Cells 2020; 9:cells9020365. [PMID: 32033274 PMCID: PMC7072216 DOI: 10.3390/cells9020365] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/29/2020] [Accepted: 02/01/2020] [Indexed: 12/17/2022] Open
Abstract
Persistent neural activity has been observed in vivo during working memory tasks, and supports short-term (up to tens of seconds) retention of information. While synaptic and intrinsic cellular mechanisms of persistent firing have been proposed, underlying cellular mechanisms are not yet fully understood. In vitro experiments have shown that individual neurons in the hippocampus and other working memory related areas support persistent firing through intrinsic cellular mechanisms that involve the transient receptor potential canonical (TRPC) channels. Recent behavioral studies demonstrating the involvement of TRPC channels on working memory make the hypothesis that TRPC driven persistent firing supports working memory a very attractive one. However, this view has been challenged by recent findings that persistent firing in vitro is unchanged in TRPC knock out (KO) mice. To assess the involvement of TRPC channels further, we tested novel and highly specific TRPC channel blockers in cholinergically induced persistent firing in mice CA1 pyramidal cells for the first time. The application of the TRPC4 blocker ML204, TRPC5 blocker clemizole hydrochloride, and TRPC4 and 5 blocker Pico145, all significantly inhibited persistent firing. In addition, intracellular application of TRPC4 and TRPC5 antibodies significantly reduced persistent firing. Taken together these results indicate that TRPC4 and 5 channels support persistent firing in CA1 pyramidal neurons. Finally, we discuss possible scenarios causing these controversial observations on the role of TRPC channels in persistent firing.
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10
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Dimiza F, Lazou M, Papadopoulos AN, Hatzidimitriou AG, Psomas G. Manganese(II) coordination compounds of carboxylate non-steroidal anti-inflammatory drugs. J Inorg Biochem 2020; 203:110906. [DOI: 10.1016/j.jinorgbio.2019.110906] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/30/2019] [Accepted: 10/24/2019] [Indexed: 02/06/2023]
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11
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Sun JF, Xu YJ, Kong XH, Su Y, Wang ZY. Fenamates inhibit human sodium channel Nav1.7 and Nav1.8. Neurosci Lett 2019; 696:67-73. [DOI: 10.1016/j.neulet.2018.12.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/06/2018] [Accepted: 12/04/2018] [Indexed: 11/27/2022]
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12
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Chuhma N, Mingote S, Yetnikoff L, Kalmbach A, Ma T, Ztaou S, Sienna AC, Tepler S, Poulin JF, Ansorge M, Awatramani R, Kang UJ, Rayport S. Dopamine neuron glutamate cotransmission evokes a delayed excitation in lateral dorsal striatal cholinergic interneurons. eLife 2018; 7:39786. [PMID: 30295607 PMCID: PMC6175576 DOI: 10.7554/elife.39786] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 09/18/2018] [Indexed: 02/06/2023] Open
Abstract
Dopamine neurons have different synaptic actions in the ventral and dorsal striatum (dStr), but whether this heterogeneity extends to dStr subregions has not been addressed. We have found that optogenetic activation of dStr dopamine neuron terminals in mouse brain slices pauses the firing of cholinergic interneurons in both the medial and lateral subregions, while in the lateral subregion the pause is shorter due to a subsequent excitation. This excitation is mediated mainly by metabotropic glutamate receptor 1 (mGluR1) and partially by dopamine D1-like receptors coupled to transient receptor potential channel 3 and 7. DA neurons do not signal to spiny projection neurons in the medial dStr, while they elicit ionotropic glutamate responses in the lateral dStr. The DA neurons mediating these excitatory signals are in the substantia nigra (SN). Thus, SN dopamine neurons engage different receptors in different postsynaptic neurons in different dStr subregions to convey strikingly different signals. Editorial note This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
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Affiliation(s)
- Nao Chuhma
- Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, United States.,Department of Psychiatry, Columbia University, New York, United States
| | - Susana Mingote
- Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, United States.,Department of Psychiatry, Columbia University, New York, United States
| | - Leora Yetnikoff
- Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, United States.,Department of Psychology, College of Staten Island, New York, United States.,CUNY Neuroscience Collaborative, The Graduate Center, City University of New York, New York, United States
| | - Abigail Kalmbach
- Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, United States.,Department of Psychiatry, Columbia University, New York, United States.,Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, United States
| | - Thong Ma
- Department of Neurology, Columbia University, New York, United States
| | - Samira Ztaou
- Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, United States.,Department of Psychiatry, Columbia University, New York, United States
| | - Anna-Claire Sienna
- Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, United States.,Department of Psychiatry, Columbia University, New York, United States
| | - Sophia Tepler
- Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, United States.,Department of Psychiatry, Columbia University, New York, United States
| | | | - Mark Ansorge
- Department of Psychiatry, Columbia University, New York, United States.,Department of Developmental Neuroscience, New York State Psychiatric Institute, New York, United States
| | | | - Un Jung Kang
- Department of Neurology, Columbia University, New York, United States
| | - Stephen Rayport
- Department of Molecular Therapeutics, New York State Psychiatric Institute, New York, United States.,Department of Psychiatry, Columbia University, New York, United States
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Ansari SS, Yousuf I, Arjmand F, Siddiqi MK, Naqvi S. Exploring the intermolecular interactions and contrasting binding of flufenamic acid with hemoglobin and lysozyme: A biophysical and docking insight. Int J Biol Macromol 2018; 116:1105-1118. [DOI: 10.1016/j.ijbiomac.2018.05.052] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 04/22/2018] [Accepted: 05/10/2018] [Indexed: 12/13/2022]
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14
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Kumar V, Tewari S, Balendra, Karmakar S, Ramanan A. Synthesis, Crystal Structures and Binding Studies of Flufenamic‐ Acid‐Based Metal Complexes. ChemistrySelect 2018. [DOI: 10.1002/slct.201800992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Vineet Kumar
- Department of ChemistryIndian Institute of Technology Delhi, Hauz Khas New Delhi-110016 India
| | - Shailabh Tewari
- Department of ChemistryIndian Institute of Technology Delhi, Hauz Khas New Delhi-110016 India
| | - Balendra
- Department of ChemistryIndian Institute of Technology Delhi, Hauz Khas New Delhi-110016 India
| | - Sandip Karmakar
- Department of ChemistryIndian Institute of Technology Delhi, Hauz Khas New Delhi-110016 India
| | - Arunachalam Ramanan
- Department of ChemistryIndian Institute of Technology Delhi, Hauz Khas New Delhi-110016 India
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15
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Suzuki R, Fujita T, Mizuta K, Kumamoto E. Inhibition by non-steroidal anti-inflammatory drugs of compound action potentials in frog sciatic nerve fibers. Biomed Pharmacother 2018; 103:326-335. [PMID: 29665554 DOI: 10.1016/j.biopha.2018.04.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/06/2018] [Accepted: 04/06/2018] [Indexed: 02/01/2023] Open
Abstract
AIMS Although antinociception produced by non-steroidal anti-inflammatory drugs (NSAIDs) is partly attributed to nerve conduction inhibition, this has not been thoroughly examined yet. The aim of the present study was to reveal quantitatively how various types of NSAIDs affect compound action potentials (CAPs), a measure of nerve conduction. MAIN METHODS CAPs were recorded from the frog sciatic nerve by using the air-gap method. KEY FINDINGS Soaking the sciatic nerve with acetic acid-based NSAIDs (diclofenac and aceclofenac) reduced the peak amplitude of CAP in a concentration-dependent manner; their IC50 values were 0.94 and 0.47 mM, respectively. Other acetic acid-based NSAIDs (indomethacin, acemetacin and etodolac) also inhibited CAPs [the extent of inhibition: some 40% (1 mM), 40% (0.5 mM) and 15% (1 mM), respectively], except for sulindac and felbinac at 1 mM that had no effects on CAP peak amplitudes. A similar inhibition was produced by fenamic acid-based NSAIDs [tolfenamic acid (IC50 = 0.29 mM), meclofenamic acid (0.19 mM), flufenamic acid (0.22 mM) and mefenamic acid] which are similar in chemical structure to diclofenac and aceclofenac; their derivatives (2,6-dichlorodiphenylamine and N-phenylanthranilic acid) also inhibited. On the other hand, salicylic acid-based (aspirin), propionic acid-based (ketoprofen, naproxen, ibuprofen, loxoprofen and flurbiprofen) and enolic acid-based (meloxicam and piroxicam) NSAIDs had no effects on CAP peak amplitudes. SIGNIFICANCE At least a part of antinociception produced by NSAIDs used as a dermatological drug to alleviate pain may be attributed to their inhibitory effects on nerve conduction, which depend on the chemical structures of NSAIDs.
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Affiliation(s)
- Rika Suzuki
- Department of Physiology, Saga Medical School, Nabeshima 5-1-1, Saga 849-8501, Japan
| | - Tsugumi Fujita
- Department of Physiology, Saga Medical School, Nabeshima 5-1-1, Saga 849-8501, Japan
| | - Kotaro Mizuta
- Department of Physiology, Saga Medical School, Nabeshima 5-1-1, Saga 849-8501, Japan
| | - Eiichi Kumamoto
- Department of Physiology, Saga Medical School, Nabeshima 5-1-1, Saga 849-8501, Japan.
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Transient Receptor Potential Channels TRPM4 and TRPC3 Critically Contribute to Respiratory Motor Pattern Formation but not Rhythmogenesis in Rodent Brainstem Circuits. eNeuro 2018; 5:eN-NWR-0332-17. [PMID: 29435486 PMCID: PMC5806591 DOI: 10.1523/eneuro.0332-17.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 01/12/2018] [Accepted: 01/16/2018] [Indexed: 12/17/2022] Open
Abstract
Transient receptor potential channel, TRPM4, the putative molecular substrate for Ca2+-activated nonselective cation current (ICAN), is hypothesized to generate bursting activity of pre-Bötzinger complex (pre-BötC) inspiratory neurons and critically contribute to respiratory rhythmogenesis. Another TRP channel, TRPC3, which mediates Na+/Ca2+ fluxes, may be involved in regulating Ca2+-related signaling, including affecting TRPM4/ICAN in respiratory pre-BötC neurons. However, TRPM4 and TRPC3 expression in pre-BötC inspiratory neurons and functional roles of these channels remain to be determined. By single-cell multiplex RT-PCR, we show mRNA expression for these channels in pre-BötC inspiratory neurons in rhythmically active medullary in vitro slices from neonatal rats and mice. Functional contributions were analyzed with pharmacological inhibitors of TRPM4 or TRPC3 in vitro as well as in mature rodent arterially perfused in situ brainstem-spinal cord preparations. Perturbations of respiratory circuit activity were also compared with those by a blocker of ICAN. Pharmacologically attenuating endogenous activation of TRPM4, TRPC3, or ICANin vitro similarly reduced the amplitude of inspiratory motoneuronal activity without significant perturbations of inspiratory frequency or variability of the rhythm. Amplitude perturbations were correlated with reduced inspiratory glutamatergic pre-BötC neuronal activity, monitored by multicellular dynamic calcium imaging in vitro. In more intact circuits in situ, the reduction of pre-BötC and motoneuronal inspiratory activity amplitude was accompanied by reduced post-inspiratory motoneuronal activity, without disruption of rhythm generation. We conclude that endogenously activated TRPM4, which likely mediates ICAN, and TRPC3 channels in pre-BötC inspiratory neurons play fundamental roles in respiratory pattern formation but are not critically involved in respiratory rhythm generation.
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Lin EC, Combe CL, Gasparini S. Differential Contribution of Ca 2+-Dependent Mechanisms to Hyperexcitability in Layer V Neurons of the Medial Entorhinal Cortex. Front Cell Neurosci 2017; 11:182. [PMID: 28713246 PMCID: PMC5491848 DOI: 10.3389/fncel.2017.00182] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 06/13/2017] [Indexed: 11/13/2022] Open
Abstract
Temporal lobe epilepsy is characterized by recurrent seizures in one or both temporal lobes of the brain; some in vitro models show that epileptiform discharges initiate in entorhinal layer V neurons and then spread into other areas of the temporal lobe. We previously found that, in the presence of GABAA receptor antagonists, stimulation of afferent fibers, terminating both at proximal and distal dendritic locations, initiated hyperexcitable bursts in layer V medial entorhinal neurons. We investigated the differential contribution of Ca2+-dependent mechanisms to the plateaus underlying these bursts at proximal and distal synapses. We found that the NMDA glutamatergic antagonist D,L-2-amino-5-phosphonovaleric acid (APV; 50 μM) reduced both the area and duration of the bursts at both proximal and distal synapses by about half. The L-type Ca2+ channel blocker nimodipine (10 μM) and the R- and T-type Ca2+ channel blocker NiCl2 (200 μM) decreased the area of the bursts to a lesser extent; none of these effects appeared to be location-dependent. Remarkably, the perfusion of flufenamic acid (FFA; 100 μM), to block Ca2+-activated non-selective cation currents (ICAN) mediated by transient receptor potential (TRP) channels, had a location-dependent effect, by abolishing burst firing and switching the suprathreshold response to a single action potential (AP) for proximal stimulation, but only minimally affecting the bursts evoked by distal stimulation. A similar outcome was found when FFA was pressure-applied locally around the proximal dendrite of the recorded neurons and in the presence of a selective blocker of melastatin TRP (TRPM) channels, 9-phenanthrol (100 μM), whereas a selective blocker of canonical TRP (TRPC) channels, SKF 96365, did not affect the bursts. These results indicate that different mechanisms might contribute to the initiation of hyperexcitability in layer V neurons at proximal and distal synapses and could shed light on the initiation of epileptiform activity in the entorhinal cortex.
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Affiliation(s)
- Eric C Lin
- Neuroscience Center of Excellence, Louisiana State University Health Sciences CenterNew Orleans, LA, United States
| | - Crescent L Combe
- Neuroscience Center of Excellence, Louisiana State University Health Sciences CenterNew Orleans, LA, United States
| | - Sonia Gasparini
- Neuroscience Center of Excellence, Louisiana State University Health Sciences CenterNew Orleans, LA, United States.,Department of Cell Biology and Anatomy, Louisiana State University Health Sciences CenterNew Orleans, LA, United States
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Pongkorpsakol P, Yimnual C, Chatsudthipong V, Rukachaisirikul V, Muanprasat C. Cellular mechanisms underlying the inhibitory effect of flufenamic acid on chloride secretion in human intestinal epithelial cells. J Pharmacol Sci 2017; 134:93-100. [PMID: 28651800 DOI: 10.1016/j.jphs.2017.05.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/09/2017] [Accepted: 05/19/2017] [Indexed: 01/10/2023] Open
Abstract
Intestinal Cl- secretion is involved in the pathogenesis of secretory diarrheas including cholera. We recently demonstrated that flufenamic acid (FFA) suppressed Vibrio cholerae El Tor variant-induced intestinal fluid secretion via mechanisms involving AMPK activation and NF-κB-suppression. The present study aimed to investigate the effect of FFA on transepithelial Cl- secretion in human intestinal epithelial (T84) cells. FFA inhibited cAMP-dependent Cl- secretion in T84 cell monolayers with IC50 of ∼8 μM. Other fenamate drugs including tolfenamic acid, meclofenamic acid and mefenamic acid exhibited the same effect albeit with lower potency. FFA also inhibited activities of CFTR, a cAMP-activated apical Cl- channel, and KCNQ1/KCNE3, a cAMP-activated basolateral K+ channel. Mechanisms of CFTR inhibition by FFA did not involve activation of its negative regulators. Interestingly, FFA inhibited Ca2+-dependent Cl- secretion with IC50 of ∼10 μM. FFA inhibited activities of Ca2+-activated Cl- channels and KCa3.1, a Ca2+-activated basolateral K+ channels, but had no effect on activities of Na+-K+-Cl- cotransporters and Na+-K+ ATPases. These results indicate that FFA inhibits both cAMP and Ca2+-dependent Cl- secretion by suppressing activities of both apical Cl- channels and basolateral K+ channels. FFA and other fenamate drugs may be useful in the treatment of secretory diarrheas.
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Affiliation(s)
- Pawin Pongkorpsakol
- Translational Medicine Graduate Program, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Rama VI Road, Rajathevi, Bangkok 10400, Thailand
| | - Chantapol Yimnual
- Department of Physiology, Faculty of Science, Mahidol University, Rama VI Road, Rajathevi, Bangkok 10400, Thailand
| | - Varanuj Chatsudthipong
- Department of Physiology, Faculty of Science, Mahidol University, Rama VI Road, Rajathevi, Bangkok 10400, Thailand
| | - Vatcharin Rukachaisirikul
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
| | - Chatchai Muanprasat
- Department of Physiology, Faculty of Science, Mahidol University, Rama VI Road, Rajathevi, Bangkok 10400, Thailand; Excellent Center for Drug Discovery (ECDD), Mahidol University, Rama VI Road, Rajathevi, Bangkok 10400, Thailand.
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Respiratory Rhythm Generation: The Whole Is Greater Than the Sum of the Parts. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1015:147-161. [DOI: 10.1007/978-3-319-62817-2_9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Quaresma S, André V, Fernandes A, Duarte MT. Mechanochemistry – A green synthetic methodology leading to metallodrugs, metallopharmaceuticals and bio-inspired metal-organic frameworks. Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2016.09.033] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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21
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Tarushi A, Kastanias P, Raptopoulou CP, Psycharis V, Kessissoglou DP, Papadopoulos AN, Psomas G. Zinc complexes of flufenamic acid: Characterization and biological evaluation. J Inorg Biochem 2016; 163:332-345. [PMID: 27155725 DOI: 10.1016/j.jinorgbio.2016.04.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/12/2016] [Accepted: 04/18/2016] [Indexed: 12/19/2022]
Abstract
The reaction of ZnCl2 with the non-steroidal anti-inflammatory drug flufenamic acid (Hfluf) led to the formation of complex [Zn(fluf-O)2(MeOH)4], 1. When the reaction takes places in the presence of a N,N'-donor heterocyclic ligand such as 2.2'-bipyridylamine (bipyam), 2.2'-bipyridine (bipy), 1.10-phenanthroline (phen) and 2.2'-dipyridylketone oxime (Hpko), the complexes [Zn(fluf)2(bipyam)], 2, [Zn(fluf)2(bipy)], 3, [Zn(fluf)(phen)2(H2O)](fluf)·0.2MeOH, 4·0.2MeOH and [Zn(fluf)2(Hpko)2], 5 were isolated, respectively. The complexes were characterized by physicochemical and spectroscopic techniques and the crystal structures of complexes 2 and 4 were determined by X-ray crystallography. The ability of the complexes to scavenge 1.1-diphenyl-picrylhydrazyl, 2.2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals and to inhibit soybean lipoxygenase was evaluated; the complexes were more active than free Hfluf. The interaction of the complexes with serum albumins was investigated by fluorescence emission spectroscopy and the corresponding binding constants were calculated. UV-vis spectroscopy, viscosity measurements and fluorescence emission spectroscopy for the competitive studies of the complexes with ethidium bromide were the techniques employed to monitor the interaction of the complexes with calf-thymus DNA and revealed intercalation as the most possible mode of binding.
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Affiliation(s)
- Alketa Tarushi
- Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, P.O. Box 135, GR-54124 Thessaloniki, Greece
| | - Philippos Kastanias
- Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, P.O. Box 135, GR-54124 Thessaloniki, Greece
| | - Catherine P Raptopoulou
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", GR-15310 Aghia Paraskevi Attikis, Greece
| | - Vassilis Psycharis
- Institute of Nanoscience and Nanotechnology, NCSR "Demokritos", GR-15310 Aghia Paraskevi Attikis, Greece
| | - Dimitris P Kessissoglou
- Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, P.O. Box 135, GR-54124 Thessaloniki, Greece
| | - Athanasios N Papadopoulos
- Department of Nutrition and Dietetics, Faculty of Food Technology and Nutrition, Alexandrion Technological Educational Institution, Sindos, Thessaloniki, Greece
| | - George Psomas
- Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, P.O. Box 135, GR-54124 Thessaloniki, Greece.
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22
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Tserkezidou C, Hatzidimitriou AG, Psomas G. Nickel(II) complexes of flufenamic acid: Characterization, structure and interaction with DNA and albumins. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.05.044] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Malami S, Kyari H, Danjuma NM, Ya'u J, Hussaini IM. Anticonvulsant properties of methanol leaf extract of Laggera Aurita Linn. F. (Asteraceae) in laboratory animals. JOURNAL OF ETHNOPHARMACOLOGY 2016; 191:301-306. [PMID: 27321277 DOI: 10.1016/j.jep.2016.06.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 06/13/2016] [Accepted: 06/13/2016] [Indexed: 06/06/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Preparation of Laggera aurita Linn. (Asteraceae) is widely used in traditional medicine to treat various kinds of diseases such as epilepsy, malaria, fever, pain and asthma. Its efficacy is widely acclaimed among communities in Northern Nigeria. AIM OF THE STUDY The present study is aimed at establishing the possible anticonvulsant effects of the methanol leaf extract of Laggera aurita using acute and chronic anticonvulsant models. MATERIALS AND METHOD Median lethal dose (LD50) was determined in mice and rats via oral and intraperitoneal routes. Anticonvulsant screening of the extract was performed using maximal electroshock-induced seizure test in day-old chicks; pentylenetetrazole-, strychnine- and picrotoxin- induced seizure models in mice. Similarly; its effects on pentylenetetrazole-induce kindling in rats as well as when co-administered with fluphenamic and cyproheptadine in mice, were evaluated. RESULTS Median lethal dose (LD50) values were found to be >5000mg/kg, p.o. and 2154mg/kg, i.p., each for both rats and mice. The extract showed dose dependent protection against tonic hind limb extension (THLE) and significantly (p<0.05) decreased the mean recovery from seizure in the maximal electroshock-induced seizure. In the pentylenetetrazole-induced seizure model, the extract offered 50% protection at 600mg/kg and also increased the mean onset of seizure at all doses with significant (p<0.05) increase at the highest dose (600mg/kg). Similarly the extract produced significant (p<0.05) increase in the onset of seizures in both strychnine- and picrotoxin- induced seizure models, at all the doses except at 150mg/kg for the picrotoxin model. Co-administration of fluphenamic acid (FFA) (5mg/kg) and the extract (600mg/kg) showed an enhanced effect with percentage protection of 70% while co-administration of FFA (5mg/kg) and phenytoin (5mg/kg) as well phenytoin (5mg/kg) and the extract (600mg/kg) produced an additive effect. Administration of the extract (600mg/kg), phenytoin (20mg/kg) and cyproheptadine (4mg/kg) offered 40%, 100% and 0% protection against THLE, each respectively, while co-administration of cyproheptadine (4mg/kg) and the extract (600mg/kg) as well as co-administration of cyproheptadine (4mg/kg) and phenytoin (20mg/kg) offered reduced protection of 20% and 50% each respectively. The extract at all doses reduced the severity of seizure episodes induced by PTZ-induced kindling. CONCLUSION The results suggest that the methanol leaf extract of Laggera aurita possesses anticonvulsant and antiepileptogenic properties.
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Affiliation(s)
- S Malami
- Department of Pharmacology and Therapeutics, Bayero University, Kano, Nigeria.
| | - H Kyari
- Department of Pharmacology and Therapeutics, Ahmadu Bello University, Zaria, Nigeria
| | - N M Danjuma
- Department of Pharmacology and Therapeutics, Ahmadu Bello University, Zaria, Nigeria
| | - J Ya'u
- Department of Pharmacology and Therapeutics, Ahmadu Bello University, Zaria, Nigeria
| | - I M Hussaini
- Department of Pharmacology, University of Maiduguri, Maiduguri, Nigeria
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Tsiliou S, Kefala LA, Hatzidimitriou AG, Kessissoglou DP, Perdih F, Papadopoulos AN, Turel I, Psomas G. Cobalt(II) complexes with non-steroidal anti-inflammatory drugs and α-diimines. J Inorg Biochem 2016; 160:125-39. [DOI: 10.1016/j.jinorgbio.2015.12.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 11/23/2015] [Accepted: 12/16/2015] [Indexed: 01/16/2023]
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25
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Photochemical transformation of flufenamic acid by artificial sunlight in aqueous solutions. J Photochem Photobiol A Chem 2016. [DOI: 10.1016/j.jphotochem.2015.10.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Rybak IA, Molkov YI, Jasinski PE, Shevtsova NA, Smith JC. Rhythmic bursting in the pre-Bötzinger complex: mechanisms and models. PROGRESS IN BRAIN RESEARCH 2015; 209:1-23. [PMID: 24746040 DOI: 10.1016/b978-0-444-63274-6.00001-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The pre-Bötzinger complex (pre-BötC), a neural structure involved in respiratory rhythm generation, can generate rhythmic bursting activity in vitro that persists after blockade of synaptic inhibition. Experimental studies have identified two mechanisms potentially involved in this activity: one based on the persistent sodium current (INaP) and the other involving calcium (ICa) and/or calcium-activated nonspecific cation (ICAN) currents. In this modeling study, we investigated bursting generated in single neurons and excitatory neural populations with randomly distributed conductances of INaP and ICa. We analyzed the possible roles of these currents, the Na(+)/K(+) pump, synaptic mechanisms, and network interactions in rhythmic bursting generated under different conditions. We show that a population of synaptically coupled excitatory neurons with randomly distributed INaP- and/or ICAN-mediated burst generating mechanisms can operate in different oscillatory regimes with bursting dependent on either current or independent of both. The existence of multiple oscillatory regimes and their state dependence may explain rhythmic activities observed in the pre-BötC under different conditions.
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Affiliation(s)
- Ilya A Rybak
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA.
| | - Yaroslav I Molkov
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA; Department of Mathematical Sciences, Indiana University-Purdue University, Indianapolis, IN, USA
| | - Patrick E Jasinski
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Natalia A Shevtsova
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Jeffrey C Smith
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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Wittkowski KM, Sonakya V, Bigio B, Tonn MK, Shic F, Ascano M, Nasca C, Gold-Von Simson G. A novel computational biostatistics approach implies impaired dephosphorylation of growth factor receptors as associated with severity of autism. Transl Psychiatry 2014; 4:e354. [PMID: 24473445 PMCID: PMC3905234 DOI: 10.1038/tp.2013.124] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 11/16/2013] [Accepted: 11/25/2013] [Indexed: 01/05/2023] Open
Abstract
The prevalence of autism spectrum disorders (ASDs) has increased 20-fold over the past 50 years to >1% of US children. Although twin studies attest to a high degree of heritability, the genetic risk factors are still poorly understood. We analyzed data from two independent populations using u-statistics for genetically structured wide-locus data and added data from unrelated controls to explore epistasis. To account for systematic, but disease-unrelated differences in (non-randomized) genome-wide association studies (GWAS), a correlation between P-values and minor allele frequency with low granularity data and for conducting multiple tests in overlapping genetic regions, we present a novel study-specific criterion for 'genome-wide significance'. From recent results in a comorbid disease, childhood absence epilepsy, we had hypothesized that axonal guidance and calcium signaling are involved in autism as well. Enrichment of the results in both studies with related genes confirms this hypothesis. Additional ASD-specific variations identified in this study suggest protracted growth factor signaling as causing more severe forms of ASD. Another cluster of related genes suggests chloride and potassium ion channels as additional ASD-specific drug targets. The involvement of growth factors suggests the time of accelerated neuronal growth and pruning at 9-24 months of age as the period during which treatment with ion channel modulators would be most effective in preventing progression to more severe forms of autism. By extension, the same computational biostatistics approach could yield profound insights into the etiology of many common diseases from the genetic data collected over the last decade.
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Affiliation(s)
- K M Wittkowski
- The Rockefeller University, Center for Clinical and Translational Science, New York, NY, USA
| | - V Sonakya
- The Rockefeller University, Center for Clinical and Translational Science, New York, NY, USA
| | - B Bigio
- The Rockefeller University, Center for Clinical and Translational Science, New York, NY, USA
| | - M K Tonn
- Hochschule Koblenz, RheinAhrCampus, Joseph-Rovan-Allee 2, Remagen, Germany
| | - F Shic
- Yale School of Medicine, Yale Autism Program, New Haven, CT, USA
| | - M Ascano
- Tuschl Laboratory of RNA Molecular Biology, The Rockefeller University, New York, NY, USA
| | - C Nasca
- McEwen Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY, USA
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Do canonical transient receptor potential channels mediate cholinergic excitation of cortical pyramidal neurons? Neuroreport 2014; 24:550-4. [PMID: 23652155 DOI: 10.1097/wnr.0b013e3283621344] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Activation of M1-type muscarinic acetylcholine receptors excites neocortical pyramidal neurons, in part by gating a nonselective cation conductance that produces calcium-dependent 'afterdepolarizing potentials' (ADPs) following short trains of action potentials. Although the identity of the cation conductance mediating the ADP is not known, previous work has implicated canonical transient receptor potential (TRPC) channels, specifically the TRPC5 and TRPC6 subtypes. Using pharmacological and genetic approaches, we tested the role of TRPC channels in generating cholinergic ADPs in layer 5 pyramidal neurons in the mouse medial prefrontal cortex (mPFC). A variety of compounds that block TRPC channels, including 2-aminoethoxydiphenyl borate, flufenamic acid, lanthanum, SKF-96365, and Pyr-3, had little, if any, impact on cholinergic ADPs. Similarly, genetic deletion of several TRPC subunits, including TPRC1, TRPC5, and TRPC6 (single knockouts), or both TRPC5 and TRPC6 together (double knockout), failed to reduce the amplitude of cholinergic ADPs. These data suggest that TRPC5 and TRPC6 subunits are not required for cholinergic excitation of layer 5 pyramidal neurons in the mouse mPFC and that the focus of future work should be expanded to test the involvement of other potential ionic effectors.
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Bradley E, Webb TI, Hollywood MA, Sergeant GP, McHale NG, Thornbury KD. The cardiac sodium current Na(v)1.5 is functionally expressed in rabbit bronchial smooth muscle cells. Am J Physiol Cell Physiol 2013; 305:C427-35. [PMID: 23784541 DOI: 10.1152/ajpcell.00034.2013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A collagenase-proteinase mixture was used to isolate airway smooth muscle cells (ASMC) from rabbit bronchi, and membrane currents were recorded using the whole cell patch-clamp technique. Stepping from -100 mV to a test potential of -40 mV evoked a fast voltage-dependent Na(+) current, sometimes with an amplitude of several nanoamperes. The current disappeared within 15 min of exposure to papain + DTT (n = 6). Comparison of the current in ASMC with current mediated by NaV1.5 α-subunits expressed in human embryonic kidney cells revealed similar voltage dependences of activation (V1/2 = -42 mV for NaV1.5) and sensitivities to TTX (IC50 = 1.1 and 1.2 μM for ASMC and NaV1.5, respectively). The current in ASMC was also blocked by lidocaine (IC50 = 160 μM). Although veratridine, an agonist of voltage-gated Na(+) channels, reduced the peak current by 33%, it slowed inactivation, resulting in a fourfold increase in sustained current (measured at 25 ms after onset). In current-clamp mode, veratridine prolonged evoked action potentials from 37 ± 9 to 1,053 ± 410 ms (n = 8). Primers for NaV1.2-1.9 were used to amplify mRNA from groups of ∼20 isolated ASMC and from whole bronchial tissue by RT-PCR. Transcripts for NaV1.2, NaV1.3, and NaV1.5-1.9 were detected in whole tissue, but only NaV1.2 and NaV1.5 were detected in single cells. We conclude that freshly dispersed rabbit ASMC express a fast voltage-gated Na(+) current that is mediated mainly by the NaV1.5 subtype.
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Affiliation(s)
- E Bradley
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
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Park YY, Johnston D, Gray R. Slowly inactivating component of Na+ current in peri-somatic region of hippocampal CA1 pyramidal neurons. J Neurophysiol 2013; 109:1378-90. [PMID: 23236005 PMCID: PMC3602831 DOI: 10.1152/jn.00435.2012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 12/07/2012] [Indexed: 11/22/2022] Open
Abstract
The properties of voltage-gated ion channels on the neuronal membrane shape electrical activity such as generation and backpropagation of action potentials, initiation of dendritic spikes, and integration of synaptic inputs. Subthreshold currents mediated by sodium channels are of interest because of their activation near rest, slow inactivation kinetics, and consequent effects on excitability. Modulation of these currents can also perturb physiological responses of a neuron that might underlie pathological states such as epilepsy. Using nucleated patches from the peri-somatic region of hippocampal CA1 neurons, we recorded a slowly inactivating component of the macroscopic Na(+) current (which we have called INaS) that shared many biophysical properties with the persistent Na(+) current, INaP, but showed distinctively faster inactivating kinetics. Ramp voltage commands with a velocity of 400 mV/s were found to elicit this component of Na(+) current reliably. INaS also showed a more hyperpolarized I-V relationship and slower inactivation than those of the fast transient Na(+) current (INaT) recorded in the same patches. The peak amplitude of INaS was proportional to the peak amplitude of INaT but was much smaller in amplitude. Hexanol, riluzole, and ranolazine, known Na(+) channel blockers, were tested to compare their effects on both INaS and INaT. The peak conductance of INaS was preferentially blocked by hexanol and riluzole, but the shift of half-inactivation voltage (V1/2) was only observed in the presence of riluzole. Current-clamp measurements with hexanol suggested that INaS was involved in generation of an action potential and in upregulation of neuronal excitability.
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Affiliation(s)
- Yul Young Park
- Center for Learning and Memory, Univ. of Texas at Austin, Austin, TX 78712-0805, USA
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Tolia C, Papadopoulos AN, Raptopoulou CP, Psycharis V, Garino C, Salassa L, Psomas G. Copper(II) interacting with the non-steroidal antiinflammatory drug flufenamic acid: structure, antioxidant activity and binding to DNA and albumins. J Inorg Biochem 2013; 123:53-65. [PMID: 23528572 DOI: 10.1016/j.jinorgbio.2013.02.009] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 02/08/2013] [Accepted: 02/20/2013] [Indexed: 12/20/2022]
Abstract
Copper(II) complexes with the non-steroidal antiinflammatory drug flufenamic acid (Hfluf) in the presence of N,N-dimethylformamide (DMF) or nitrogen donor heterocyclic ligands (2,2'-bipyridylamine (bipyam), 1,10-phenanthroline (phen), 2,2'-bipyridine (bipy) or pyridine (py)) have been synthesized and characterized. The crystal structures of [Cu2(fluf)4(DMF)2], 1, and [Cu(fluf)(bipyam)Cl], 2, have been determined by X-ray crystallography. Density functional theory (DFT) (CAM-B3LYP/LANL2DZ/6-31G**) was employed to determine the structure of complex 2 and its analogues (complexes [Cu(fluf)(phen)Cl], 3, [Cu(fluf)(bipy)Cl], 4 and [Cu(fluf)2(py)2], 5). Time-dependent DFT calculations of doublet-doublet transitions show that the lowest-energy band in the absorption spectrum of 2-5 has a mixed d-d/LMCT character. UV study of the interaction of the complexes with calf-thymus DNA (CT DNA) has shown that the complexes can bind to CT DNA with [Cu(fluf)(bipy)Cl] exhibiting the highest binding constant to CT DNA. The complexes can bind to CT DNA via intercalation as concluded by studying the cyclic voltammograms of the complexes in the presence of CT DNA solution and by DNA solution viscosity measurements. Competitive studies with ethidium bromide (EB) have shown that the complexes can displace the DNA-bound EB suggesting strong competition with EB. Flufenamic acid and its Cu(II) complexes exhibit good binding affinity to human or bovine serum albumin protein with high binding constant values. All compounds have been tested for their antioxidant and free radical scavenging activity as well as for their in vitro inhibitory activity against soybean lipoxygenase showing significant activity with [Cu(fluf)(phen)Cl] being the most active.
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Affiliation(s)
- Charikleia Tolia
- Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
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The TRPM4 non-selective cation channel contributes to the mammalian atrial action potential. J Mol Cell Cardiol 2013; 59:11-9. [PMID: 23416167 DOI: 10.1016/j.yjmcc.2013.01.019] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 01/15/2013] [Accepted: 01/28/2013] [Indexed: 01/21/2023]
Abstract
The TRPM4 calcium-activated non-selective monovalent cation channel has been reported in mammalian atrial cardiomyocytes, but its implication in this tissue remains unknown. We used a combination of pharmacological tools and disruption of the Trpm4 gene in mice to investigate the channel implication in atrial action potential (AP). To search for TRPM4 activity, single channel currents were recorded on freshly isolated atrial cardiomyocytes using the patch-clamp technique. To investigate TRPM4 implication in AP, the transmembrane potential was recorded on the multicellular preparation using intracellular microelectrodes after isolating the mouse atrium, under electrical stimulation (rate=5Hz). Isolated atrial cardiomyocytes from the Trpm4(+/+) mouse expressed a typical TRPM4 current while cardiomyocytes from Trpm4(-/-) mouse did not. The Trpm4(+/+) mouse atrium exhibited AP durations at 50, 70 and 90% repolarization of 8.9±0.5ms, 16.0±1.0ms, and 30.2±1.6ms, respectively. The non-selective cation channel inhibitor flufenamic acid (10(-6) and 10(-5)mol·L(-1)) produced a concentration-dependent decrease in AP duration. Similarly, the TRPM4-inhibitor 9-phenanthrol reversibly reduced the duration of AP with an EC50 at 21×10(-6)mol·L(-1), which is similar to that reported for TRPM4 current inhibition in HEK-293 cells. 9-Phenanthrol had no effect on other AP parameters. The effect of 9-phenanthrol is markedly reduced in the mouse ventricle, which displays only weak expression of the channel. Moreover, atria from Trpm4(-/-) mice exhibited an AP that was 20% shorter than that of atria from littermate control mice, and the effect of 9-phenanthrol on AP was abolished in the Trpm4(-/-) mice. Our results showed that TRPM4 is implicated in the waveform of the atrial action potential. It is thus a potential target for pharmacological approaches against atrial arrhythmias.
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Guinamard R, Simard C, Del Negro C. Flufenamic acid as an ion channel modulator. Pharmacol Ther 2013; 138:272-84. [PMID: 23356979 DOI: 10.1016/j.pharmthera.2013.01.012] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 12/26/2012] [Indexed: 12/29/2022]
Abstract
Flufenamic acid has been known since the 1960s to have anti-inflammatory properties attributable to the reduction of prostaglandin synthesis. Thirty years later, flufenamic acid appeared to be an ion channel modulator. Thus, while its use in medicine diminished, its use in ionic channel research expanded. Flufenamic acid commonly not only affects non-selective cation channels and chloride channels, but also modulates potassium, calcium and sodium channels with effective concentrations ranging from 10(-6)M in TRPM4 channel inhibition to 10(-3)M in two-pore outwardly rectifying potassium channel activation. Because flufenamic acid effects develop and reverse rapidly, it is a convenient and widely used tool. However, given the broad spectrum of its targets, experimental results have to be interpreted cautiously. Here we provide an overview of ion channels targeted by flufenamic acid to aid in interpreting its effects at the molecular, cellular, and system levels. If it is used with good practices, flufenamic acid remains a useful tool for ion channel research. Understanding the targets of FFA may help reevaluate its physiological impacts and revive interest in its therapeutic potential.
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Jasinski PE, Molkov YI, Shevtsova NA, Smith JC, Rybak IA. Sodium and calcium mechanisms of rhythmic bursting in excitatory neural networks of the pre-Bötzinger complex: a computational modelling study. Eur J Neurosci 2013; 37:212-30. [PMID: 23121313 PMCID: PMC3659238 DOI: 10.1111/ejn.12042] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 08/13/2012] [Accepted: 09/26/2012] [Indexed: 11/29/2022]
Abstract
The neural mechanisms generating rhythmic bursting activity in the mammalian brainstem, particularly in the pre-Bötzinger complex (pre-BötC), which is involved in respiratory rhythm generation, and in the spinal cord (e.g. locomotor rhythmic activity) that persist after blockade of synaptic inhibition remain poorly understood. Experimental studies in rodent medullary slices containing the pre-BötC identified two mechanisms that could potentially contribute to the generation of rhythmic bursting: one based on the persistent Na(+) current (I(NaP)), and the other involving the voltage-gated Ca(2+) current (I(Ca)) and the Ca(2+) -activated nonspecific cation current (I(CAN)), activated by intracellular Ca(2+) accumulated from extracellular and intracellular sources. However, the involvement and relative roles of these mechanisms in rhythmic bursting are still under debate. In this theoretical/modelling study, we investigated Na(+)-dependent and Ca(2+)-dependent bursting generated in single cells and heterogeneous populations of synaptically interconnected excitatory neurons with I(NaP) and I(Ca) randomly distributed within populations. We analysed the possible roles of network connections, ionotropic and metabotropic synaptic mechanisms, intracellular Ca(2+) release, and the Na(+)/K(+) pump in rhythmic bursting generated under different conditions. We show that a heterogeneous population of excitatory neurons can operate in different oscillatory regimes with bursting dependent on I(NaP) and/or I(CAN), or independent of both. We demonstrate that the operating bursting mechanism may depend on neuronal excitation, synaptic interactions within the network, and the relative expression of particular ionic currents. The existence of multiple oscillatory regimes and their state dependence demonstrated in our models may explain different rhythmic activities observed in the pre-BötC and other brainstem/spinal cord circuits under different experimental conditions.
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Affiliation(s)
- Patrick E. Jasinski
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Yaroslav I. Molkov
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
- Department of Mathematical Sciences, Indiana University – Purdue University, Indianapolis, IN, USA
| | - Natalia A. Shevtsova
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Jeffrey C. Smith
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Ilya A. Rybak
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
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Yu YH, Xie W, Bao Y, Li HM, Hu SJ, Xing JL. Saikosaponin a mediates the anticonvulsant properties in the HNC models of AE and SE by inhibiting NMDA receptor current and persistent sodium current. PLoS One 2012; 7:e50694. [PMID: 23209812 PMCID: PMC3510157 DOI: 10.1371/journal.pone.0050694] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 10/23/2012] [Indexed: 11/18/2022] Open
Abstract
Epilepsy is one of the most common neurological disorders, yet its treatment remains unsatisfactory. Saikosaponin a (SSa), a triterpene saponin derived from Bupleurum chinensis DC., has been demonstrated to have significant antiepileptic activity in a variety of epilepsy models in vivo. However, the electrophysiological activities and mechanisms of the antiepileptic properties of SSa remain unclear. In this study, whole-cell current-clamp recordings were used to evaluate the anticonvulsant activities of SSa in the hippocampal neuronal culture (HNC) models of acquired epilepsy (AE) and status epilepticus (SE). Whole-cell voltage-clamp recordings were used to evaluate the modulation effects of SSa on NMDA-evoked current and sodium currents in cultured hippocampal neurons. We found that SSa effectively terminated spontaneous recurrent epileptiform discharges (SREDs) in the HNC model of AE and continuous epileptiform high-frequency bursts (SE) in the HNC model of SE, in a concentration-dependent manner with an IC(50) of 0.42 µM and 0.62 µM, respectively. Furthermore, SSa significantly reduced the peak amplitude of NMDA-evoked current and the peak current amplitude of I(NaP). These results suggest for the first time that the inhibitions of NMDA receptor current and I(NaP) may be the underlying mechanisms of SSa's anticonvulsant properties, including the suppression of SREDs and SE in the HNC models of AE and SE. In addition, effectively abolishing the refractory SE implies that SSa may be a potential anticonvulsant candidate for the clinical treatment of epilepsy.
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Affiliation(s)
- Yun-Hong Yu
- Department of Traditional Chinese Medicine, Nanfang Hospital, Southern Medical University, Guang Zhou, People’s Republic of China
- School of Traditional Chinese Medicine, Southern Medical University, Guang Zhou, People’s Republic of China
- Institute of Neuroscience, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - Wei Xie
- Department of Traditional Chinese Medicine, Nanfang Hospital, Southern Medical University, Guang Zhou, People’s Republic of China
- School of Traditional Chinese Medicine, Southern Medical University, Guang Zhou, People’s Republic of China
- * E-mail: (WX); (JLX)
| | - Yong Bao
- Department of Neurology, Traditional Chinese Hospital of Lu’an, Lu’an, People’s Republic of China
| | - Hui-Ming Li
- Institute of Neuroscience, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - San-Jue Hu
- Institute of Neuroscience, Fourth Military Medical University, Xi’an, People’s Republic of China
| | - Jun-Ling Xing
- Institute of Neuroscience, Fourth Military Medical University, Xi’an, People’s Republic of China
- * E-mail: (WX); (JLX)
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36
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Saito Y, Yanagawa Y. Ca(2+)-activated ion currents triggered by ryanodine receptor-mediated Ca(2+) release control firing of inhibitory neurons in the prepositus hypoglossi nucleus. J Neurophysiol 2012; 109:389-404. [PMID: 23100137 DOI: 10.1152/jn.00617.2012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Spontaneous miniature outward currents (SMOCs) are known to exist in smooth muscles and peripheral neurons, and evidence for the presence of SMOCs in central neurons has been accumulating. SMOCs in central neurons are induced through Ca(2+)-activated K(+) (K(Ca)) channels, which are activated through Ca(2+)-induced Ca(2+) release from the endoplasmic reticulum via ryanodine receptors (RyRs). Previously, we found that some neurons in the prepositus hypoglossi nucleus (PHN) showed spontaneous outward currents (SOCs). In the present study, we used whole cell recordings in slice preparations of the rat brain stem to investigate the following: 1) the ionic mechanisms of SOCs, 2) the types of neurons exhibiting frequent SOCs, and 3) the effect of Ca(2+)-activated conductance on neuronal firing. Pharmacological analyses revealed that SOCs were induced via the activation of small-conductance-type K(Ca) (SK) channels and RyRs, indicating that SOCs correspond to SMOCs. An analysis of the voltage responses to current pulses of the fluorescence-expressing inhibitory neurons of transgenic rats revealed that inhibitory neurons frequently exhibited SOCs. Abolition of SOCs via blockade of SK channels enhanced the frequency of spontaneous firing of inhibitory PHN neurons. However, abolition of SOCs via blockade of RyRs reduced the firing frequency and hyperpolarized the membrane potential. Similar reductions in firing frequency and hyperpolarization were also observed when Ca(2+)-activated nonselective cation (CAN) channels were blocked. These results suggest that, in inhibitory neurons in the PHN, Ca(2+) release via RyRs activates SK and CAN channels, and these channels regulate spontaneous firing in a complementary manner.
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Affiliation(s)
- Yasuhiko Saito
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
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37
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Kuo SP, Lu HW, Trussell LO. Intrinsic and synaptic properties of vertical cells of the mouse dorsal cochlear nucleus. J Neurophysiol 2012; 108:1186-98. [PMID: 22572947 DOI: 10.1152/jn.00778.2011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Multiple classes of inhibitory interneurons shape the activity of principal neurons of the dorsal cochlear nucleus (DCN), a primary target of auditory nerve fibers in the mammalian brain stem. Feedforward inhibition mediated by glycinergic vertical cells (also termed tuberculoventral or corn cells) is thought to contribute importantly to the sound-evoked response properties of principal neurons, but the cellular and synaptic properties that determine how vertical cells function are unclear. We used transgenic mice in which glycinergic neurons express green fluorescent protein (GFP) to target vertical cells for whole cell patch-clamp recordings in acute slices of DCN. We found that vertical cells express diverse intrinsic spiking properties and could fire action potentials at high, sustained spiking rates. Using paired recordings, we directly examined synapses made by vertical cells onto fusiform cells, a primary DCN principal cell type. Vertical cell synapses produced unexpectedly small-amplitude unitary currents in fusiform cells, and additional experiments indicated that multiple vertical cells must be simultaneously active to inhibit fusiform cell spike output. Paired recordings also revealed that a major source of inhibition to vertical cells comes from other vertical cells.
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Affiliation(s)
- Sidney P Kuo
- Neuroscience Graduate Program, Oregon Health and Science University, Portland, OR, USA
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38
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Merriam LA, Roman CW, Baran CN, Girard BM, May V, Parsons RL. Pretreatment with nonselective cationic channel inhibitors blunts the PACAP-induced increase in guinea pig cardiac neuron excitability. J Mol Neurosci 2012; 48:721-9. [PMID: 22528456 DOI: 10.1007/s12031-012-9763-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 03/26/2012] [Indexed: 11/29/2022]
Abstract
Calcium influx is required for the pituitary adenylyl cyclase activating polypeptide (PACAP)-induced increase in guinea pig cardiac neuron excitability, noted as a change from a phasic to multiple action potential firing pattern. Intracellular recordings indicated that pretreatment with the nonselective cationic channel inhibitors, 2-aminoethoxydiphenylborate (2-APB), 1-[β-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole HCl (SKF 96365), and flufenamic acid (FFA) reduced the 20-nM PACAP-induced excitability increase. Additional experiments tested whether 2-APB, FFA, and SKF 96365 could suppress the increase in excitability by PACAP once it had developed. The increased action potential firing remained following application of 2-APB but was diminished by FFA. SKF 96365 transiently depressed the PACAP-induced excitability increase. A decrease and recovery of action potential amplitude paralleled the excitability shift. Since semiquantitative PCR indicated that cardiac neurons express TRPC subunit transcripts, we hypothesize that PACAP activates calcium-permeable, nonselective cationic channels, which possibly are members of the TRPC family. Our results are consistent with calcium influx being required for the initiation of the PACAP-induced increase in excitability, but suggest that it may not be required to sustain the peptide effect. The present results also demonstrate that nonselective cationic channel inhibitors could have other actions, which might contribute to the inhibition of the PACAP-induced excitability increase.
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Affiliation(s)
- Laura A Merriam
- Department of Anatomy and Neurobiology, College of Medicine, University of Vermont, Burlington, VT 05405, USA
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39
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Chi Y, Li K, Yan Q, Koizumi S, Shi L, Takahashi S, Zhu Y, Matsue H, Takeda M, Kitamura M, Yao J. Nonsteroidal Anti-Inflammatory Drug Flufenamic Acid Is a Potent Activator of AMP-Activated Protein Kinase. J Pharmacol Exp Ther 2011; 339:257-66. [DOI: 10.1124/jpet.111.183020] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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40
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Membrane voltage fluctuations reduce spike frequency adaptation and preserve output gain in CA1 pyramidal neurons in a high-conductance state. J Neurosci 2011; 31:3880-93. [PMID: 21389243 DOI: 10.1523/jneurosci.5076-10.2011] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Modulating the gain of the input-output function of neurons is critical for processing of stimuli and network dynamics. Previous gain control mechanisms have suggested that voltage fluctuations play a key role in determining neuronal gain in vivo. Here we show that, under increased membrane conductance, voltage fluctuations restore Na(+) current and reduce spike frequency adaptation in rat hippocampal CA1 pyramidal neurons in vitro. As a consequence, membrane voltage fluctuations produce a leftward shift in the frequency-current relationship without a change in gain, relative to an increase in conductance alone. Furthermore, we show that these changes have important implications for the integration of inhibitory inputs. Due to the ability to restore Na(+) current, hyperpolarizing membrane voltage fluctuations mediated by GABA(A)-like inputs can increase firing rate in a high-conductance state. Finally, our data show that the effects on gain and synaptic integration are mediated by voltage fluctuations within a physiologically relevant range of frequencies (10-40 Hz).
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Lee CR, Witkovsky P, Rice ME. Regulation of Substantia Nigra Pars Reticulata GABAergic Neuron Activity by H₂O₂ via Flufenamic Acid-Sensitive Channels and K ATP Channels. Front Syst Neurosci 2011; 5:14. [PMID: 21503158 PMCID: PMC3074506 DOI: 10.3389/fnsys.2011.00014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2011] [Accepted: 03/05/2011] [Indexed: 11/13/2022] Open
Abstract
Substantia nigra pars reticulata (SNr) GABAergic neurons are key output neurons of the basal ganglia. Given the role of these neurons in motor control, it is important to understand factors that regulate their firing rate and pattern. One potential regulator is hydrogen peroxide (H₂O₂), a reactive oxygen species that is increasingly recognized as a neuromodulator. We used whole-cell current clamp recordings of SNr GABAergic neurons in guinea-pig midbrain slices to determine how H₂O₂ affects the activity of these neurons and to explore the classes of ion channels underlying those effects. Elevation of H₂O₂ levels caused an increase in the spontaneous firing rate of SNr GABAergic neurons, whether by application of exogenous H₂O₂ or amplification of endogenous H₂O₂ through inhibition of glutathione peroxidase with mercaptosuccinate. This effect was reversed by flufenamic acid (FFA), implicating transient receptor potential (TRP) channels. Conversely, depletion of endogenous H₂O₂ by catalase, a peroxidase enzyme, decreased spontaneous firing rate and firing precision of SNr neurons, demonstrating tonic control of firing rate by H₂O₂. Elevation of H₂O₂ in the presence of FFA revealed an inhibition of tonic firing that was prevented by blockade of ATP-sensitive K(+) (K(ATP)) channels with glibenclamide. In contrast to guinea-pig SNr neurons, the dominant effect of H₂O₂ elevation in mouse SNr GABAergic neurons was hyperpolarization, indicating a species difference in H₂O₂-dependent regulation. Thus, H₂O₂ is an endogenous modulator of SNr GABAergic neurons, acting primarily through presumed TRP channels in guinea-pig SNr, with additional modulation via K(ATP) channels to regulate SNr output.
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Affiliation(s)
- Christian R Lee
- Department of Neurosurgery, New York University School of Medicine New York, NY, USA
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42
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Mrejeru A, Wei A, Ramirez JM. Calcium-activated non-selective cation currents are involved in generation of tonic and bursting activity in dopamine neurons of the substantia nigra pars compacta. J Physiol 2011; 589:2497-514. [PMID: 21486760 DOI: 10.1113/jphysiol.2011.206631] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Nigral dopamine neurons are transiently activated by high frequency glutamatergic inputs relaying reward-predicting sensory information. The tonic firing pattern of dopamine cells responds to these inputs with a transient burst of spikes that requires NMDA receptors. Here, we show that NMDA receptor activation further excites the cell by recruiting a calcium-activated non-selective cation current (ICAN) capable of generating a plateau potential. Burst firing in vitro is eliminated after blockade of ICAN with flufenamic acid, 9-phenanthrol, or intracellular BAPTA. ICAN is likely to be mediated by a transient receptor potential (TRP) channel, and RT-PCR was used to confirm expression of TRPM2 and TRPM4mRNA in substantia nigra pars compacta.We propose that ICAN is selectively activated during burst firing to boost NMDA currents and allow plateau potentials. This boost mechanism may render DA cells vulnerable to excitotoxicity.
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Affiliation(s)
- Ana Mrejeru
- Committee on Neurobiology, University of Chicago, Chicago, IL 60637, USA
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43
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Hill AA, Garcia AJ, Zanella S, Upadhyaya R, Ramirez JM. Graded reductions in oxygenation evoke graded reconfiguration of the isolated respiratory network. J Neurophysiol 2010; 105:625-39. [PMID: 21084689 DOI: 10.1152/jn.00237.2010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neurons depend on aerobic metabolism, yet are very sensitive to oxidative stress and, as a consequence, typically operate in a low O(2) environment. The balance between blood flow and metabolic activity, both of which can vary spatially and dynamically, suggests that local O(2) availability markedly influences network output. Yet the understanding of the underlying O(2)-sensing mechanisms is limited. Are network responses regulated by discrete O(2)-sensing mechanisms or, rather, are they the consequence of inherent O(2) sensitivities of mechanisms that generate the network activity? We hypothesized that a broad range of O(2) tensions progressively modulates network activity of the pre-Bötzinger complex (preBötC), a neuronal network critical to the central control of breathing. Rhythmogenesis was measured from the preBötC in transverse neonatal mouse brain stem slices that were exposed to graded reductions in O(2) between 0 and 95% O(2), producing tissue oxygenation values ranging from 20 ± 18 (mean ± SE) to 440 ± 56 Torr at the slice surface, respectively. The response of the preBötC to graded changes in O(2) is progressive for some metrics and abrupt for others, suggesting that different aspects of the respiratory network have different sensitivities to O(2).
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Affiliation(s)
- Andrew A Hill
- New Jersey Institute of Technology and Rutgers University, 195 University Drive, Boyden Hall, Newark, NJ 07102, USA.
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