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Cucchiara F, Frumento P, Banfi T, Sesso G, Di Galante M, D'Ascanio P, Valvo G, Sicca F, Faraguna U. Electrophysiological features of sleep in children with Kir4.1 channel mutations and Autism-Epilepsy phenotype: a preliminary study. Sleep 2021; 43:5625283. [PMID: 31722434 PMCID: PMC7157183 DOI: 10.1093/sleep/zsz255] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 09/17/2019] [Indexed: 12/24/2022] Open
Abstract
Study Objectives Recently, a role for gain-of-function (GoF) mutations of the astrocytic potassium channel Kir4.1 (KCNJ10 gene) has been proposed in subjects with Autism–Epilepsy phenotype (AEP). Epilepsy and autism spectrum disorder (ASD) are common and complexly related to sleep disorders. We tested whether well characterized mutations in KCNJ10 could result in specific sleep electrophysiological features, paving the way to the discovery of a potentially relevant biomarker for Kir4.1-related disorders. Methods For this case–control study, we recruited seven children with ASD either comorbid or not with epilepsy and/or EEG paroxysmal abnormalities (AEP) carrying GoF mutations of KCNJ10 and seven children with similar phenotypes but wild-type for the same gene, comparing period-amplitude features of slow waves detected by fronto-central bipolar EEG derivations (F3-C3, F4-C4, and Fz-Cz) during daytime naps. Results Children with Kir4.1 mutations displayed longer slow waves periods than controls, in Fz-Cz (mean period = 112,617 ms ± SE = 0.465 in mutated versus mean period = 105,249 ms ± SE = 0.375 in controls, p < 0.001). An analog result was found in F3-C3 (mean period = 125,706 ms ± SE = 0.397 in mutated versus mean period = 120,872 ms ± SE = 0.472 in controls, p < 0.001) and F4-C4 (mean period = 127,914 ms ± SE = 0.557 in mutated versus mean period = 118,174 ms ± SE = 0.442 in controls, p < 0.001). Conclusion This preliminary finding suggests that period-amplitude slow wave features are modified in subjects carrying Kir4.1 GoF mutations. Potential clinical applications of this finding are discussed.
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Affiliation(s)
- Federico Cucchiara
- SONNOLab, Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy.,Clinical Pharmacology and Pharmacogenetic Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Paolo Frumento
- Unit of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Tommaso Banfi
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pontedera, Italy
| | - Gianluca Sesso
- Neuropsychiatry Complex Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Marco Di Galante
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Paola D'Ascanio
- SONNOLab, Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy
| | - Giulia Valvo
- Child and Adolescent Neuropsychiatric Unit, Azienda USL Toscana Sudest, Grosseto, Italy
| | - Federico Sicca
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Ugo Faraguna
- SONNOLab, Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy
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Popov A, Brazhe A, Denisov P, Sutyagina O, Li L, Lazareva N, Verkhratsky A, Semyanov A. Astrocyte dystrophy in ageing brain parallels impaired synaptic plasticity. Aging Cell 2021; 20:e13334. [PMID: 33675569 PMCID: PMC7963330 DOI: 10.1111/acel.13334] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 12/30/2020] [Accepted: 02/08/2021] [Indexed: 01/02/2023] Open
Abstract
Little is known about age-dependent changes in structure and function of astrocytes and of the impact of these on the cognitive decline in the senescent brain. The prevalent view on the age-dependent increase in reactive astrogliosis and astrocytic hypertrophy requires scrutiny and detailed analysis. Using two-photon microscopy in conjunction with 3D reconstruction, Sholl and volume fraction analysis, we demonstrate a significant reduction in the number and the length of astrocytic processes, in astrocytic territorial domains and in astrocyte-to-astrocyte coupling in the aged brain. Probing physiology of astrocytes with patch clamp, and Ca2+ imaging revealed deficits in K+ and glutamate clearance and spatiotemporal reorganisation of Ca2+ events in old astrocytes. These changes paralleled impaired synaptic long-term potentiation (LTP) in hippocampal CA1 in old mice. Our findings may explain the astroglial mechanisms of age-dependent decline in learning and memory.
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Affiliation(s)
- Alexander Popov
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Institute of NeuroscienceNizhny Novgorod UniversityNizhny NovgorodRussia
| | - Alexey Brazhe
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Faculty of BiologyMoscow State UniversityMoscowRussia
| | - Pavel Denisov
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Institute of NeuroscienceNizhny Novgorod UniversityNizhny NovgorodRussia
| | - Oksana Sutyagina
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Institute of NeuroscienceNizhny Novgorod UniversityNizhny NovgorodRussia
| | - Li Li
- Department of PhysiologyJiaxing University College of MedicineZhejiang ProChina
| | | | - Alexei Verkhratsky
- Sechenov First Moscow State Medical UniversityMoscowRussia
- Faculty of Biology, Medicine and HealthThe University of ManchesterManchesterUK
- Achucarro Center for NeuroscienceIKERBASQUEBasque Foundation for ScienceBilbaoSpain
- Department of NeurosciencesUniversity of the Basque Country UPV/EHU and CIBERNEDLeioaSpain
| | - Alexey Semyanov
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Faculty of BiologyMoscow State UniversityMoscowRussia
- Sechenov First Moscow State Medical UniversityMoscowRussia
- Department of PhysiologyJiaxing University College of MedicineZhejiang ProChina
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Walch E, Murphy TR, Cuvelier N, Aldoghmi M, Morozova C, Donohue J, Young G, Samant A, Garcia S, Alvarez C, Bilas A, Davila D, Binder DK, Fiacco TA. Astrocyte-Selective Volume Increase in Elevated Extracellular Potassium Conditions Is Mediated by the Na +/K + ATPase and Occurs Independently of Aquaporin 4. ASN Neuro 2020; 12:1759091420967152. [PMID: 33092407 PMCID: PMC7586494 DOI: 10.1177/1759091420967152] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 09/23/2020] [Indexed: 12/26/2022] Open
Abstract
Astrocytes and neurons have been shown to swell across a variety of different conditions, including increases in extracellular potassium concentration (^[K+]o). The mechanisms involved in the coupling of K+ influx to water movement into cells leading to cell swelling are not well understood and remain controversial. Here, we set out to determine the effects of ^[K+]o on rapid volume responses of hippocampal CA1 pyramidal neurons and stratum radiatum astrocytes using real-time confocal volume imaging. First, we found that elevating [K+]o within a physiological range (to 6.5 mM and 10.5 mM from a baseline of 2.5 mM), and even up to pathological levels (26 mM), produced dose-dependent increases in astrocyte volume, with absolutely no effect on neuronal volume. In the absence of compensating for addition of KCl by removal of an equal amount of NaCl, neurons actually shrank in ^[K+]o, while astrocytes continued to exhibit rapid volume increases. Astrocyte swelling in ^[K+]o was not dependent on neuronal firing, aquaporin 4, the inwardly rectifying potassium channel Kir 4.1, the sodium bicarbonate cotransporter NBCe1, , or the electroneutral cotransporter, sodium-potassium-chloride cotransporter type 1 (NKCC1), but was significantly attenuated in 1 mM barium chloride (BaCl2) and by the Na+/K+ ATPase inhibitor ouabain. Effects of 1 mM BaCl2 and ouabain applied together were not additive and, together with reports that BaCl2 can inhibit the NKA at high concentrations, suggests a prominent role for the astrocyte NKA in rapid astrocyte volume increases occurring in ^[K+]o. These findings carry important implications for understanding mechanisms of cellular edema, regulation of the brain extracellular space, and brain tissue excitability.
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Affiliation(s)
- Erin Walch
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, United States
- Center for Glial-Neuronal Interactions, University of California, Riverside, Riverside, United States
| | - Thomas R. Murphy
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
| | - Nicholas Cuvelier
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
- Interdepartmental Graduate Program in Neuroscience, University of California, Riverside, Riverside, United States
| | - Murad Aldoghmi
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
| | - Cristine Morozova
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
- Undergraduate Major in Neuroscience, University of California, Riverside, Riverside, United States
| | - Jordan Donohue
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
- Interdepartmental Graduate Program in Neuroscience, University of California, Riverside, Riverside, United States
| | - Gaby Young
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
- Undergraduate Major in Neuroscience, University of California, Riverside, Riverside, United States
| | - Anuja Samant
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
- Undergraduate Major in Neuroscience, University of California, Riverside, Riverside, United States
| | - Stacy Garcia
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
- Undergraduate Major in Neuroscience, University of California, Riverside, Riverside, United States
| | - Camila Alvarez
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
- Undergraduate Major in Neuroscience, University of California, Riverside, Riverside, United States
| | - Alex Bilas
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
- Interdepartmental Graduate Program in Neuroscience, University of California, Riverside, Riverside, United States
| | - David Davila
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
| | - Devin K. Binder
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, United States
- Center for Glial-Neuronal Interactions, University of California, Riverside, Riverside, United States
- Interdepartmental Graduate Program in Neuroscience, University of California, Riverside, Riverside, United States
| | - Todd A. Fiacco
- Center for Glial-Neuronal Interactions, University of California, Riverside, Riverside, United States
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
- Interdepartmental Graduate Program in Neuroscience, University of California, Riverside, Riverside, United States
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5
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Breithausen B, Kautzmann S, Boehlen A, Steinhäuser C, Henneberger C. Limited contribution of astroglial gap junction coupling to buffering of extracellular K + in CA1 stratum radiatum. Glia 2019; 68:918-931. [PMID: 31743499 DOI: 10.1002/glia.23751] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/25/2019] [Accepted: 10/29/2019] [Indexed: 12/21/2022]
Abstract
Astrocytes form large networks, in which individual cells are connected via gap junctions. It is thought that this astroglial gap junction coupling contributes to the buffering of extracellular K+ increases. However, it is largely unknown how the control of extracellular K+ by astroglial gap junction coupling depends on the underlying activity patterns and on the magnitude of extracellular K+ increases. We explored this dependency in acute hippocampal slices (CA1, stratum radiatum) by direct K+ -sensitive microelectrode recordings and acute pharmacological inhibition of gap junctions. K+ transients evoked by synaptic and axonal activity were largely unaffected by acute astroglial uncoupling in slices obtained from young and adult rats. Iontophoretic K+ -application enabled us to generate K+ gradients with defined spatial properties and magnitude. By varying the K+ -iontophoresis position and protocol, we found that acute pharmacological uncoupling increases the amplitude of K+ transients once their initial amplitude exceeded ~10 mM. Our experiments demonstrate that the contribution of gap junction coupling to buffering of extracellular K+ gradients is limited to large and localized K+ increases.
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Affiliation(s)
- Björn Breithausen
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany
| | - Steffen Kautzmann
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany
| | - Anne Boehlen
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, University of Bonn Medical School, Bonn, Germany.,Institute of Neurology, University College London, London, UK.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
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6
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Wanke E, Gullo F, Dossi E, Valenza G, Becchetti A. Neuron-glia cross talk revealed in reverberating networks by simultaneous extracellular recording of spikes and astrocytes' glutamate transporter and K+ currents. J Neurophysiol 2016; 116:2706-2719. [PMID: 27683885 PMCID: PMC5133298 DOI: 10.1152/jn.00509.2016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 09/22/2016] [Indexed: 01/11/2023] Open
Abstract
In neocortex networks, we simultaneously captured spikes and the slower astrocytes' K+and glutamate transporter (GluT) currents with the use of individual MEA electrodes. Inward and outward K+currents in different regions of the glial syncytium suggested that spatial buffering was operant. Moreover, in organotypic slices from ventral tegmental area and prefrontal cortex, the large GluT current amplitudes allowed to measure transporter currents with a single electrode. Our method allows direct study of the dynamic interplay of different cell types in excitable and nonexcitable tissue. Astrocytes uptake synaptically released glutamate with electrogenic transporters (GluT) and buffer the spike-dependent extracellular K+ excess with background K+ channels. We studied neuronal spikes and the slower astrocytic signals on reverberating neocortical cultures and organotypic slices from mouse brains. Spike trains and glial responses were simultaneously captured from individual sites of multielectrode arrays (MEA) by splitting the recorded traces into appropriate filters and reconstructing the original signal by deconvolution. GluT currents were identified by using dl-threo-β-benzyloxyaspartate (TBOA). K+ currents were blocked by 30 μM Ba2+, suggesting a major contribution of inwardly rectifying K+ currents. Both types of current were tightly correlated with the spike rate, and their astrocytic origin was tested in primary cultures by blocking glial proliferation with cytosine β-d-arabinofuranoside (AraC). The spike-related, time-locked inward and outward K+ currents in different regions of the astrocyte syncytium were consistent with the assumptions of the spatial K+ buffering model. In organotypic slices from ventral tegmental area and prefrontal cortex, the GluT current amplitudes exceeded those observed in primary cultures by several orders of magnitude, which allowed to directly measure transporter currents with a single electrode. Simultaneously measuring cell signals displaying widely different amplitudes and kinetics will help clarify the neuron-glia interplay and make it possible to follow the cross talk between different cell types in excitable as well as nonexcitable tissue.
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Affiliation(s)
- Enzo Wanke
- Department of Biotechnologies and Biosciences and Milan Center For Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy; and
| | - Francesca Gullo
- Department of Biotechnologies and Biosciences and Milan Center For Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy; and
| | - Elena Dossi
- Department of Biotechnologies and Biosciences and Milan Center For Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy; and
| | - Gaetano Valenza
- Research Centre "E. Piaggio" and Department of Information Engineering, School of Engineering, University of Pisa, Pisa, Italy
| | - Andrea Becchetti
- Department of Biotechnologies and Biosciences and Milan Center For Neuroscience (NeuroMI), University of Milano-Bicocca, Milan, Italy; and
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