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Conjoint analysis of influence of LC-HCL and Mor-HCL on Vth and neurite length in hippocampal neuronal network. Neurosci Lett 2021; 751:135801. [PMID: 33705932 DOI: 10.1016/j.neulet.2021.135801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 01/25/2021] [Accepted: 03/01/2021] [Indexed: 11/21/2022]
Abstract
Lidocaine hydrochloride (LC-HCl) and morphine hydrochloride (Mor-HCl) are two kinds of most prevalently used anesthetics. However, their influences on electrical excitability of hippocampal neuronal networks and hippocampal brain slices were rarely studied. Previously, our group have assessed the influence of acetylcholine, alcohol and temperature change on the excitability of neural networks with the so-called Voltage Threshold Measurement Method (VTMM) based on microelectrode array (MEA). In this paper, we will study the influence of LC-HCl and Mor-HCl on the electrical excitability of neural networks and the morphological features of neurons, and discuss the relations between the changes of electrical excitability of neural networks and the morphological changes of neurons. The results of VTMM showed: The voltage threshold (VTh) of hippocampal neuronal networks and hippocampal brain slices first increased and then decreased as the LC-HCl concentration increased. The VTh of hippocampal neuronal networks and hippocampal brain slices increased as the Mor-HCl concentration increased. The results of HCS experiments showed: The neurite length change of cultured hippocampal neuronal networks increased first and then decreased with increased LC-HCl concentration, but decreased as the Mor-HCl concentration increased. The combined analysis of VTMM and HCS experiments showed that under effects of the two drugs, the VTh and the hippocampal neurite length were strongly negatively correlated.
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Almeida CGM, Costa-Higuchi K, Piovesan AR, Moro CF, Venturin GT, Greggio S, Costa-Ferro ZS, Salamoni SD, Peigneur S, Tytgat J, de Lima ME, Silva CND, Vinadé L, Rowan EG, DaCosta JC, Dal Belo CA, Carlini CR. Neurotoxic and convulsant effects induced by jack bean ureases on the mammalian nervous system. Toxicology 2021; 454:152737. [PMID: 33631299 DOI: 10.1016/j.tox.2021.152737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/18/2021] [Accepted: 02/20/2021] [Indexed: 12/14/2022]
Abstract
Ureases are microbial virulence factors either because of the enzymatic release of ammonia or due to many other non-enzymatic effects. Here we studied two neurotoxic urease isoforms, Canatoxin (CNTX) and Jack Bean Urease (JBU), produced by the plant Canavalia ensiformis, whose mechanisms of action remain elusive. The neurotoxins provoke convulsions in rodents (LD50 ∼2 mg/kg) and stimulate exocytosis in cell models, affecting intracellular calcium levels. Here, electrophysiological and brain imaging techniques were applied to elucidate their mode of action. While systemic administration of the toxins causes tonic-clonic seizures in rodents, JBU injected into rat hippocampus induced spike-wave discharges similar to absence-like seizures. JBU reduced the amplitude of compound action potential from mouse sciatic nerve in a tetrodotoxin-insensitive manner. Hippocampal slices from CNTX-injected animals or slices treated in vitro with JBU failed to induce long term potentiation upon tetanic stimulation. Rat cortical synaptosomes treated with JBU released L-glutamate. JBU increased the intracellular calcium levels and spontaneous firing rate in rat hippocampus neurons. MicroPET scans of CNTX-injected rats revealed increased [18]Fluoro-deoxyglucose uptake in epileptogenesis-related areas like hippocampus and thalamus. Curiously, CNTX did not affect voltage-gated sodium, calcium or potassium channels currents, neither did it interfere on cholinergic receptors, suggesting an indirect mode of action that could be related to the ureases' membrane-disturbing properties. Understanding the neurotoxic mode of action of C. ensiformis ureases could help to unveil the so far underappreciated relevance of these toxins in diseases caused by urease-producing microorganisms, in which the human central nervous system is affected.
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Affiliation(s)
- Carlos Gabriel Moreira Almeida
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Medicine and Health Sciences, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Kiyo Costa-Higuchi
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Materials Technology and Engineering, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Angela Regina Piovesan
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Celular and Molecular Biology, Center of Biotechnology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Carlo Frederico Moro
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Medicine and Health Sciences, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Gianina Teribele Venturin
- Preclinical Research Center, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Samuel Greggio
- Preclinical Research Center, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Zaquer Susana Costa-Ferro
- Laboratory of Neuroscience, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Simone Denise Salamoni
- Laboratory of Neuroscience, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Steve Peigneur
- Laboratory of Toxicology & Pharmacology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Jan Tytgat
- Laboratory of Toxicology & Pharmacology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Maria Elena de Lima
- Institute of Teaching and Research, Santa Casa de Belo Horizonte, Belo Horizonte, MG, Brazil
| | | | - Lúcia Vinadé
- Laboratory of Neurobiology and Toxinology (Lanetox), Universidade Federal do Pampa, São Gabriel, RS, Brazil
| | - Edward G Rowan
- Strathclyde Institute for Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Jaderson Costa DaCosta
- Laboratory of Neuroscience, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Cháriston André Dal Belo
- Laboratory of Neurobiology and Toxinology (Lanetox), Universidade Federal do Pampa, São Gabriel, RS, Brazil.
| | - Celia Regina Carlini
- Laboratory of Neurotoxins, Brain Institute of Rio Grande do Sul (BraIns), Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Medicine and Health Sciences, School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil; Scholl of Medicine, Pontificía Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Winlow W, Polese G, Moghadam HF, Ahmed IA, Di Cosmo A. Sense and Insensibility - An Appraisal of the Effects of Clinical Anesthetics on Gastropod and Cephalopod Molluscs as a Step to Improved Welfare of Cephalopods. Front Physiol 2018; 9:1147. [PMID: 30197598 PMCID: PMC6117391 DOI: 10.3389/fphys.2018.01147] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/31/2018] [Indexed: 12/24/2022] Open
Abstract
Recent progress in animal welfare legislation stresses the need to treat cephalopod molluscs, such as Octopus vulgaris, humanely, to have regard for their wellbeing and to reduce their pain and suffering resulting from experimental procedures. Thus, appropriate measures for their sedation and analgesia are being introduced. Clinical anesthetics are renowned for their ability to produce unconsciousness in vertebrate species, but their exact mechanisms of action still elude investigators. In vertebrates it can prove difficult to specify the differences of response of particular neuron types given the multiplicity of neurons in the CNS. However, gastropod molluscs such as Aplysia, Lymnaea, or Helix, with their large uniquely identifiable nerve cells, make studies on the cellular, subcellular, network and behavioral actions of anesthetics much more feasible, particularly as identified cells may also be studied in culture, isolated from the rest of the nervous system. To date, the sorts of study outlined above have never been performed on cephalopods in the same way as on gastropods. However, criteria previously applied to gastropods and vertebrates have proved successful in developing a method for humanely anesthetizing Octopus with clinical doses of isoflurane, i.e., changes in respiratory rate, color pattern and withdrawal responses. However, in the long term, further refinements will be needed, including recordings from the CNS of intact animals in the presence of a variety of different anesthetic agents and their adjuvants. Clues as to their likely responsiveness to other appropriate anesthetic agents and muscle relaxants can be gained from background studies on gastropods such as Lymnaea, given their evolutionary history.
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Affiliation(s)
- William Winlow
- Department of Biology, University of Naples Federico II, Naples, Italy
- Institute of Ageing and Chronic Diseases, University of Liverpool, Liverpool, United Kingdom
- NPC Newton, Preston, United Kingdom
| | - Gianluca Polese
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Hadi-Fathi Moghadam
- Department of Physiology, Faculty of Medicine, Physiology Research Centre, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | | | - Anna Di Cosmo
- Department of Biology, University of Naples Federico II, Naples, Italy
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Armstrong R, Riaz S, Hasan S, Iqbal F, Rice T, Syed N. Mechanisms of Anesthetic Action and Neurotoxicity: Lessons from Molluscs. Front Physiol 2018; 8:1138. [PMID: 29410627 PMCID: PMC5787087 DOI: 10.3389/fphys.2017.01138] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 12/27/2017] [Indexed: 01/17/2023] Open
Abstract
Anesthesia is a prerequisite for most surgical procedures in both animals and humans. Significant strides have been made in search of effective and safer compounds that elicit rapid induction and recovery from anesthesia. However, recent studies have highlighted possible negative effects of several anesthetic agents on the developing brain. The precise nature of this cytotoxicity remains to be determined mainly due to the complexity and the intricacies of the mammalian brain. Various invertebrates have contributed significantly toward our understanding of how both local and general anesthetics affect intrinsic membrane and synaptic properties. Moreover, the ability to reconstruct in vitro synapses between individually identifiable pre- and postsynaptic neurons is a unique characteristic of molluscan neurons allowing us to ask fundamental questions vis-à-vis the long-term effects of anesthetics on neuronal viability and synaptic connectivity. Here, we highlight some of the salient aspects of various molluscan organisms and their contributions toward our understanding of the fundamental mechanisms underlying the actions of anesthetic agents as well as their potential detrimental effects on neuronal growth and synaptic connectivity. We also present some novel preliminary data regarding a newer anesthetic agent, dexmedetomidine, and its effects on synaptic transmission between Lymnaea neurons. The findings presented here underscore the importance of invertebrates for research in the field of anesthesiology while highlighting their relevance to both vertebrates and humans.
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Affiliation(s)
- Ryden Armstrong
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Saba Riaz
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Sean Hasan
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Fahad Iqbal
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Tiffany Rice
- Department of Anesthesia, Alberta Children's Hospital, University of Calgary, Calgary, AB, Canada
| | - Naweed Syed
- Vi Riddell Pain Program, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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Lu TZ, Kostelecki W, Sun CLF, Dong N, Pérez Velázquez JL, Feng ZP. High sensitivity of spontaneous spike frequency to sodium leak current in a Lymnaea pacemaker neuron. Eur J Neurosci 2016; 44:3011-3022. [PMID: 27711993 DOI: 10.1111/ejn.13426] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/25/2016] [Accepted: 09/30/2016] [Indexed: 11/28/2022]
Abstract
The spontaneous rhythmic firing of action potentials in pacemaker neurons depends on the biophysical properties of voltage-gated ion channels and background leak currents. The background leak current includes a large K+ and a small Na+ component. We previously reported that a Na+ -leak current via U-type channels is required to generate spontaneous action potential firing in the identified respiratory pacemaker neuron, RPeD1, in the freshwater pond snail Lymnaea stagnalis. We further investigated the functional significance of the background Na+ current in rhythmic spiking of RPeD1 neurons. Whole-cell patch-clamp recording and computational modeling approaches were carried out in isolated RPeD1 neurons. The whole-cell current of the major ion channel components in RPeD1 neurons were characterized, and a conductance-based computational model of the rhythmic pacemaker activity was simulated with the experimental measurements. We found that the spiking rate is more sensitive to changes in the Na+ leak current as compared to the K+ leak current, suggesting a robust function of Na+ leak current in regulating spontaneous neuronal firing activity. Our study provides new insight into our current understanding of the role of Na+ leak current in intrinsic properties of pacemaker neurons.
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Affiliation(s)
- T Z Lu
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - W Kostelecki
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Neurosciences and Mental Health, Hospital for Sick Children, Toronto, ON, Canada
| | - C L F Sun
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - N Dong
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - J L Pérez Velázquez
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada.,Neurosciences and Mental Health, Hospital for Sick Children, Toronto, ON, Canada
| | - Z-P Feng
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
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Shakuo T, Lin ST, Onimaru H. The Effects of Lidocaine on Central Respiratory Neuron Activity and Nociceptive-Related Responses in the Brainstem–Spinal Cord Preparation of the Newborn Rat. Anesth Analg 2016; 122:1586-93. [DOI: 10.1213/ane.0000000000001205] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Budán F, Kovács N, Engelmann P, Horváth I, Veres DS, Németh P, Szigeti K, Máthé D. Longitudinal in vivo MR imaging of live earthworms. ACTA ACUST UNITED AC 2014; 321:479-89. [PMID: 25059556 DOI: 10.1002/jez.1880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 06/14/2014] [Accepted: 06/14/2014] [Indexed: 11/08/2022]
Abstract
Earthworm (Oligochaeta, Lumbricidae) species are used widely in eco-toxicological tests especially with contaminated soils. These long-term tests are reliable, but a high sample size is needed. Magnetic resonance imaging (MRI) can produce fast, robust, sensitive, and longitudinal morphological results using a small sample size. Performing longitudinal in vivo examinations of earthworms using MRI requires the need for anesthetics to completely avoid earthworm's moving. Our goal was to develop a simple and non-invasive method to anesthetize earthworms for in vivo longitudinal imaging studies. We investigated a number of different anesthesia methods and found that propan-2-ol and its vapor was optimal. We used a commercial sequential nanoScan® PET/MRI system (Mediso Ltd, Hungary, Budapest) to explore feasibility of MR imaging in immobilized earthworms. It was possible to visualize via micro MRI the brain, gastrointestinal tract, seminal vesicles, calciferous gland (Morren gland), and main blood vessels of the circulatory system. Our findings show the possibilities to examine changes in morphology using MRI of certain organs using a reversible, long-term immobilization method.
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Affiliation(s)
- Ferenc Budán
- CROmed, Translational Research Centers, Budapest, Baross utca, Hungary
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Lidocaine treatment during synapse reformation periods permanently inhibits NGF-induced excitation in an identified reconstructed synapse of Lymnaea stagnalis. J Anesth 2011; 26:45-53. [DOI: 10.1007/s00540-011-1257-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 09/22/2011] [Indexed: 10/15/2022]
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Onizuka S, Kasaba T, Takasaki M. The Effect of Lidocaine on Cholinergic Neurotransmission in an Identified Reconstructed Synapse. Anesth Analg 2008; 107:1236-42. [DOI: 10.1213/ane.0b013e31818064f6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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