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Groschup B, Calandra GM, Raitmayr C, Shrouder J, Llovera G, Zaki AG, Burgstaller S, Bischof H, Eroglu E, Liesz A, Malli R, Filser S, Plesnila N. Probing intracellular potassium dynamics in neurons with the genetically encoded sensor lc-LysM GEPII 1.0 in vitro and in vivo. Sci Rep 2024; 14:13753. [PMID: 38877089 PMCID: PMC11178854 DOI: 10.1038/s41598-024-62993-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 05/23/2024] [Indexed: 06/16/2024] Open
Abstract
Neuronal activity is accompanied by a net outflow of potassium ions (K+) from the intra- to the extracellular space. While extracellular [K+] changes during neuronal activity are well characterized, intracellular dynamics have been less well investigated due to lack of respective probes. In the current study we characterized the FRET-based K+ biosensor lc-LysM GEPII 1.0 for its capacity to measure intracellular [K+] changes in primary cultured neurons and in mouse cortical neurons in vivo. We found that lc-LysM GEPII 1.0 can resolve neuronal [K+] decreases in vitro during seizure-like and intense optogenetically evoked activity. [K+] changes during single action potentials could not be recorded. We confirmed these findings in vivo by expressing lc-LysM GEPII 1.0 in mouse cortical neurons and performing 2-photon fluorescence lifetime imaging. We observed an increase in the fluorescence lifetime of lc-LysM GEPII 1.0 during periinfarct depolarizations, which indicates a decrease in intracellular neuronal [K+]. Our findings suggest that lc-LysM GEPII 1.0 can be used to measure large changes in [K+] in neurons in vitro and in vivo but requires optimization to resolve smaller changes as observed during single action potentials.
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Affiliation(s)
- Bernhard Groschup
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
- Graduate School of Systemic Neurosciences, LMU Munich, Planegg-Martinsried, Germany
| | - Gian Marco Calandra
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
- Graduate School of Systemic Neurosciences, LMU Munich, Planegg-Martinsried, Germany
| | - Constanze Raitmayr
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Joshua Shrouder
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Gemma Llovera
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Asal Ghaffari Zaki
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey
- Molecular Biology, Genetics and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul, Turkey
| | - Sandra Burgstaller
- Institut für Klinische Anatomie und Zellanalytik (Österbergstraße 3), Eberhard Karls Universität Tübingen, Tübingen, Germany
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, 8010, Graz, Austria
| | - Helmut Bischof
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, 8010, Graz, Austria
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, 72076, Tübingen, Germany
| | - Emrah Eroglu
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey
- Molecular Biology, Genetics and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul, Turkey
| | - Arthur Liesz
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
- Graduate School of Systemic Neurosciences, LMU Munich, Planegg-Martinsried, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Roland Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, 8010, Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010, Graz, Austria
| | - Severin Filser
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
- Deutsches Zentrum Für Neurodegenerative Erkrankungen (DZNE), Light Microscope Facility (LMF), Bonn, Germany
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany.
- Graduate School of Systemic Neurosciences, LMU Munich, Planegg-Martinsried, Germany.
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, 72076, Tübingen, Germany.
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Bastany ZJR, Askari S, Dumont GA, Kellinghaus C, Askari B, Gharagozli K, Gorji A. Concurrent recordings of slow DC-potentials and epileptiform discharges: novel EEG amplifier and signal processing techniques. J Neurosci Methods 2023:109894. [PMID: 37245651 DOI: 10.1016/j.jneumeth.2023.109894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 05/15/2023] [Accepted: 05/19/2023] [Indexed: 05/30/2023]
Abstract
Ionic currents within the brain generate voltage oscillations consist of slow and rapid fluctuations. These bioelectrical activities include ultra-low frequency electroencephalograms (DC-EEG, frequency less than 0.1Hz) and conventional clinical electroencephalograms (AC-EEG, 0.5 to 70Hz). Although AC-EEG is commonly used for diagnosing epilepsy, recent studies indicate that DC-EEG is an essential frequency component of EEG and can provide valuable information for analyzing epileptiform discharges. During conventional EEG recordings, DC-EEG is censored by applying high-pass filtering to i) obliterate slow-wave artifacts, ii) eliminate the bioelectrodes' half-cell potential asymmetrical changes in ultralow-low frequency, and iii) prevent instrument saturation. Spreading depression (SD), which is the most prolonged fluctuation in DC-EEG, may be associated with epileptiform discharges. However, recording of SD signals from the scalp's surface can be challenging due to the filtering effect and non-neuronal slow shift potentials. In this study, we describe a novel technique to extend the frequency bandwidth of surface EEG to record SD signals. The method includes novel instrumentation, appropriate bioelectrodes, and efficient signal-processing techniques. To evaluate the accuracy of our approach, we performed a simultaneous surface recording of DC- and AC-EEG from epileptic patients during long-term video EEG monitoring, which provide a promising tool for diagnosis of epilepsy. DATA AVAILABILITY STATEMENT: The data presented in this study are available on request.
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Affiliation(s)
- Zoya J R Bastany
- Electrical and Computer Engineering Department, The University of British Columbia, Vancouver, Canada; BC Children's Hospital Research Institute, Vancouver, Canada
| | - Shahbaz Askari
- Electrical and Computer Engineering Department, The University of British Columbia, Vancouver, Canada; BC Children's Hospital Research Institute, Vancouver, Canada
| | - Guy A Dumont
- Electrical and Computer Engineering Department, The University of British Columbia, Vancouver, Canada; BC Children's Hospital Research Institute, Vancouver, Canada
| | | | - Baran Askari
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran
| | - Kurosh Gharagozli
- Epilepsy Research Center, Loghman hospital, Department of Neurology, Shahid Beheshti University of Medical Science, Tehran, Iran
| | - Ali Gorji
- Electrical and Computer Engineering Department, The University of British Columbia, Vancouver, Canada; Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Neurosurgery, Westfälische Wilhelms-Universität Münster, Germany; Epilepsy Research Center, Westfälische Wilhelms-Universität Münster, Germany.
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Berhouma M, Eker OF, Dailler F, Rheims S, Balanca B. Cortical Spreading Depolarizations in Aneurysmal Subarachnoid Hemorrhage: An Overview of Current Knowledge and Future Perspectives. Adv Tech Stand Neurosurg 2022; 45:229-244. [PMID: 35976452 DOI: 10.1007/978-3-030-99166-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Despite significant advances in the management of aneurysmal subarachnoid hemorrhage (SAH), morbidity and mortality remain devastating particularly for high-grade SAH. Poor functional outcome usually results from delayed cerebral ischemia (DCI). The pathogenesis of DCI during aneurysmal SAH has historically been attributed to cerebral vasospasm, but spreading depolarizations (SDs) are now considered to play a central role in DCI. During SAH, SDs may produce an inverse hemodynamic response leading to spreading ischemia. Several animal models have contributed to a better understanding of the pathogenesis of SDs during aneurysmal SAH and provided new therapeutic approaches including N-methyl-D-aspartate receptor antagonists and phosphodiesterase inhibitors. Herein we review the current knowledge in the field of SDs' pathogenesis and we detail the key experimental and clinical studies that have opened interesting new therapeutic approaches to prevent DCI in aneurysmal SAH.
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Affiliation(s)
- Moncef Berhouma
- Department of Neurosurgical Oncology and Vascular Neurosurgery, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon (Lyon University Hospital), Lyon, France.
- Creatis Lab, CNRS UMR 5220, INSERM U1206, Lyon 1 University, INSA Lyon, Lyon, France.
| | - Omer Faruk Eker
- Creatis Lab, CNRS UMR 5220, INSERM U1206, Lyon 1 University, INSA Lyon, Lyon, France
- Department of Interventional Neuroradiology, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon (Lyon University Hospital), Lyon, France
| | - Frederic Dailler
- Department of Neuro-Anesthesia and Neuro-Critical Care, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon (Lyon University Hospital), Lyon, France
| | - Sylvain Rheims
- Department of Functional Neurology and Epileptology, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon (Lyon University Hospital), Lyon, France
- Lyon's Neurosciences Research Center, INSERM U1028/CNRS, UMR 5292, University of Lyon, Lyon, France
| | - Baptiste Balanca
- Department of Neuro-Anesthesia and Neuro-Critical Care, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon (Lyon University Hospital), Lyon, France
- Lyon's Neurosciences Research Center, INSERM U1028/CNRS, UMR 5292, University of Lyon, Lyon, France
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Association of cortical spreading depression and seizures in patients with medically intractable epilepsy. Clin Neurophysiol 2020; 131:2861-2874. [PMID: 33152524 DOI: 10.1016/j.clinph.2020.09.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/14/2020] [Accepted: 09/07/2020] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Monitoring of the ultra-low frequency potentials, particularly cortical spreading depression (CSD), is excluded in epilepsy monitoring due to technical barriers imposed by the scalp ultra-low frequency electroencephalogram (EEG). As a result, clinical studies of CSD have been limited to invasive EEG. Therefore, the occurrence of CSD and its interaction with epileptiform field potentials (EFP) require investigation in epilepsy monitoring. METHODS Using a novel AC/DC-EEG approach, the occurrence of DC potentials in patients with intractable epilepsy presenting different symptoms of aura was investigated during long-term video-EEG monitoring. RESULTS Various forms of slow potentials, including simultaneous negative direct current (DC) potentials and prolonged EFP, propagated negative DC potentials, and non-propagated single negative DC potentials were recorded from the scalp of the epileptic patients. The propagated and single negative DC potentials preceded the prolonged EFP with a time lag and seizure appeared at the final shoulder of some instances of the propagated negative DC potentials. The slow potential deflections had a high amplitude and prolonged duration and propagated slowly through the brain. The high-frequency EEG was suppressed in the vicinity of the negative DC potential propagations. CONCLUSIONS The study is the first to report the recording of the propagated and single negative DC potentials with EFP at the scalp of patients with intractable epilepsy. The negative DC potentials preceded the prolonged EFP and may trigger seizures. The propagated and single negative DC potentials may be considered as CSD. SIGNIFICANCE Recordings of CSD may serve as diagnostic and prognostic monitoring tools in epilepsy.
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Abbott NJ, Nicholson C, Verkhratsky A. Introduction: Special Issue in Honor of Eva Syková. Neurochem Res 2019; 45:1-4. [PMID: 31858377 DOI: 10.1007/s11064-019-02924-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 11/27/2019] [Indexed: 12/12/2022]
Affiliation(s)
- N Joan Abbott
- Institute of Pharmaceutical Sciences, King's College, London, SE1 9NH, UK
| | - Charles Nicholson
- Department of Neuroscience & Physiology, NYU School of Medicine, New York, NY, 10016, USA.
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK
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