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Lewen A, Ta TT, Cesetti T, Hollnagel JO, Papageorgiou IE, Chausse B, Kann O. Neuronal gamma oscillations and activity-dependent potassium transients remain regular after depletion of microglia in postnatal cortex tissue. J Neurosci Res 2020; 98:1953-1967. [PMID: 32638411 DOI: 10.1002/jnr.24689] [Citation(s) in RCA: 5] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/09/2020] [Accepted: 06/12/2020] [Indexed: 12/28/2022]
Abstract
Microglial cells (resident macrophages) feature rapid activation in CNS disease and can acquire multiple phenotypes exerting neuroprotection or neurotoxicity. The functional impact of surveying ("resting") microglia on neural excitability and neurotransmission in physiology is widely unknown, however. We addressed this issue in male rat hippocampal slice cultures (in situ) by pharmacological microglial ablation within days and by characterizing neuronal gamma-band oscillations (30-70 Hz) that are highly sensitive to neuromodulators and disturbances in ion and energy regulation. Gamma oscillations support action potential timing and synaptic plasticity, associate with higher brain functions like perception and memory, and require precise communication between excitatory pyramidal cells and inhibitory (GABAergic) interneurons. The slice cultures featured well-preserved hippocampal cytoarchitecture and parvalbumin-positive interneuron networks, microglia with ramified morphology, and low basal levels of IL-6, TNF-α, and nitric oxide (NO). Stimulation of slice cultures with the pro-inflammatory cytokine IFN-γ or bacterial LPS serving as positive controls for microglial reactivity induced MHC-II expression and increased cytokine and NO release. Chronic exposure of slice cultures to liposome-encapsulated clodronate reduced the microglial cell population by about 96%, whereas neuronal structures, astrocyte GFAP expression, and basal levels of cytokines and NO were unchanged. Notably, the properties of gamma oscillations reflecting frequency, number and synchronization of synapse activity were regular after microglial depletion. Also, electrical stimulus-induced transients of the extracellular potassium concentration ([K+ ]o ) reflecting cellular K+ efflux, clearance and buffering were unchanged. This suggests that nonreactive microglia are dispensable for neuronal homeostasis and neuromodulation underlying network signaling and rhythm generation in cortical tissue.
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Affiliation(s)
- Andrea Lewen
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Thuy-Truc Ta
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Tiziana Cesetti
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Jan-Oliver Hollnagel
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Ismini E Papageorgiou
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany.,Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
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2
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Amelung N, Maus V, Behme D, Papageorgiou IE, Leyhe JR, Knauth M, Psychogios MN. Evaluation of an optimized metal artifact reduction algorithm for flat-detector angiography compared to DSA imaging in follow-up after neurovascular procedures. BMC Med Imaging 2019; 19:66. [PMID: 31412810 PMCID: PMC6694691 DOI: 10.1186/s12880-019-0352-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [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: 04/02/2019] [Accepted: 06/23/2019] [Indexed: 11/18/2022] Open
Abstract
Background Flat detector CT – angiography (FDCTA) has become a valuable imaging tool in post- and peri-interventional imaging after neurovascular procedures. Metal artifacts produced by radiopaque implants like clips or coils still impair image quality. Methods FDCTA was performed in periprocedural or follow-up imaging of 21 patients, who had received neurovascular treatment. Raw data was sent to a dedicated workstation and subsequently a metal artifact reduction algorithm (MARA) was applied. Two neuroradiologists examined the images. Results Application of MARA improved image appearance and led to a significant reduction of metal artifacts. After application of MARA only 8 datasets (34% of the images) were rated as having many or extensive artifacts, before MARA 15 (65%) of the images had extensive or many artifacts. Twenty percent more cases of reperfusion were diagnosed after application of MARA, congruent to the results of digital subtraction angiography (DSA) imaging. Also 3 (13% of datasets) images, which could not be evaluated before application of MARA, could be analyzed after metal artifact reduction and reperfusion could be excluded. Conclusion Application of MARA improved image evaluation, reduced the extent of metal artifacts, and more cases of reperfusion could be detected or excluded, congruent to DSA imaging.
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Affiliation(s)
- Nadine Amelung
- Institute for Diagnostic and Interventional Neuroradiology, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany.
| | - Volker Maus
- Institute for Diagnostic and Interventional Neuroradiology, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany
| | - Daniel Behme
- Institute for Diagnostic and Interventional Neuroradiology, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany
| | - Ismini E Papageorgiou
- Institute for Diagnostic and Interventional Radiology, University Hospital of Jena, Am Klinikum 1, 07747, Jena, Germany.,Institute for Radiology, Südharz Klinikum Nordhausen, Dr. Robert Koch Straße 39, 99734, Nordhausen, Germany
| | - Johanna Rosemarie Leyhe
- Institute for Diagnostic and Interventional Neuroradiology, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany
| | - Michael Knauth
- Institute for Diagnostic and Interventional Neuroradiology, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany
| | - Marios Nikos Psychogios
- Institute for Diagnostic and Interventional Neuroradiology, University Medicine Göttingen, Robert Koch Straße 40, 37075, Göttingen, Germany
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3
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Schneider J, Berndt N, Papageorgiou IE, Maurer J, Bulik S, Both M, Draguhn A, Holzhütter HG, Kann O. Local oxygen homeostasis during various neuronal network activity states in the mouse hippocampus. J Cereb Blood Flow Metab 2019; 39:859-873. [PMID: 29099662 PMCID: PMC6501513 DOI: 10.1177/0271678x17740091] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cortical information processing comprises various activity states emerging from timed synaptic excitation and inhibition. However, the underlying energy metabolism is widely unknown. We determined the cerebral metabolic rate of oxygen (CMRO2) along a tissue depth of <0.3 mm in the hippocampal CA3 region during various network activities, including gamma oscillations and sharp wave-ripples that occur during wakefulness and sleep. These physiological states associate with sensory perception and memory formation, and critically depend on perisomatic GABA inhibition. Moreover, we modelled vascular oxygen delivery based on quantitative microvasculature analysis. (1) Local CMRO2 was highest during gamma oscillations (3.4 mM/min), medium during sharp wave-ripples, asynchronous activity and isoflurane application (2.0-1.6 mM/min), and lowest during tetrodotoxin application (1.4 mM/min). (2) Energy expenditure of axonal and synaptic signaling accounted for >50% during gamma oscillations. (3) CMRO2 positively correlated with number and synchronisation of activated synapses, and neural multi-unit activity. (4) The median capillary distance was 44 µm. (5) The vascular oxygen partial pressure of 33 mmHg was needed to sustain oxidative phosphorylation during gamma oscillations. We conclude that gamma oscillations featuring high energetics require a hemodynamic response to match oxygen consumption of respiring mitochondria, and that perisomatic inhibition significantly contributes to the brain energy budget.
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Affiliation(s)
- Justus Schneider
- 1 Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Nikolaus Berndt
- 2 Computational Systems Biochemistry, Institute of Biochemistry, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ismini E Papageorgiou
- 1 Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Jana Maurer
- 1 Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Sascha Bulik
- 2 Computational Systems Biochemistry, Institute of Biochemistry, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Martin Both
- 1 Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Andreas Draguhn
- 1 Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Hermann-Georg Holzhütter
- 2 Computational Systems Biochemistry, Institute of Biochemistry, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Oliver Kann
- 1 Institute of Physiology and Pathophysiology, and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
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Papageorgiou IE, Valous NA, Lahrmann B, Janova H, Klaft ZJ, Koch A, Schneider UC, Vajkoczy P, Heppner FL, Grabe N, Halama N, Heinemann U, Kann O. Astrocytic glutamine synthetase is expressed in the neuronal somatic layers and down-regulated proportionally to neuronal loss in the human epileptic hippocampus. Glia 2018; 66:920-933. [DOI: 10.1002/glia.23292] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 12/20/2017] [Accepted: 12/21/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Ismini E. Papageorgiou
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326; Heidelberg D-69120 Germany
- Interdisciplinary Center for Neurosciences, University of Heidelberg, Im Neuenheimer Feld 364; Heidelberg D-69120 Germany
- Present address: Institute of Radiology, Südharz Klinikum Nordhausen gGmbH, Dr.-Robert-Koch-Str. 39; Nordhausen D-99734 Germany
| | - Nektarios A. Valous
- Applied Tumor Immunity Clinical Cooperation Unit, National Center for Tumor Diseases, German Cancer Research Center, Im Neuenheimer Feld 460; Heidelberg D-69120 Germany
- Department of Medical Oncology; National Center for Tumor Diseases, University Hospital Heidelberg, Im Neuenheimer Feld 460; Heidelberg D-69120 Germany
| | - Bernd Lahrmann
- Hamamatsu Tissue Imaging and Analysis Center (TIGA), National Center for Tumor Diseases, BIOQUANT, Im Neuenheimer Feld 267, University of Heidelberg; Heidelberg D-69120 Germany
- Steinbeis Transfer Center for Medical Systems Biology, Heckerstr. 9; Heidelberg D-69124 Germany
| | - Hana Janova
- Division of Clinical Neuroscience; Max Planck Institute of Experimental Medicine, Hermann-Rein-str. 3; Göttingen D-37075 Germany
| | - Zin-Juan Klaft
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1; Berlin D-10117 Germany
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Charitéplatz 1; Berlin D-10117 Germany
| | - Arend Koch
- Institute of Neuropathology, Charité-Universitätsmedizin Berlin, Charité Campus Mitte, Charitéplatz 1; Berlin D-10117 Germany
| | - Ulf C. Schneider
- Department of Neurosurgery; Charité-Universitätsmedizin Berlin, Campus Virchow Medical Center, Augustenplatz 1; Berlin D-11353 Germany
| | - Peter Vajkoczy
- Department of Neurosurgery; Charité-Universitätsmedizin Berlin, Campus Virchow Medical Center, Augustenplatz 1; Berlin D-11353 Germany
| | - Frank L. Heppner
- Institute of Neuropathology, Charité-Universitätsmedizin Berlin, Charité Campus Mitte, Charitéplatz 1; Berlin D-10117 Germany
| | - Niels Grabe
- Hamamatsu Tissue Imaging and Analysis Center (TIGA), National Center for Tumor Diseases, BIOQUANT, Im Neuenheimer Feld 267, University of Heidelberg; Heidelberg D-69120 Germany
- Steinbeis Transfer Center for Medical Systems Biology, Heckerstr. 9; Heidelberg D-69124 Germany
| | - Niels Halama
- Department of Medical Oncology; National Center for Tumor Diseases, University Hospital Heidelberg, Im Neuenheimer Feld 460; Heidelberg D-69120 Germany
| | - Uwe Heinemann
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1; Berlin D-10117 Germany
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Charitéplatz 1; Berlin D-10117 Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Im Neuenheimer Feld 326; Heidelberg D-69120 Germany
- Interdisciplinary Center for Neurosciences, University of Heidelberg, Im Neuenheimer Feld 364; Heidelberg D-69120 Germany
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Dellios N, Teichgraeber U, Chelaru R, Malich A, Papageorgiou IE. Computer-aided Detection Fidelity of Pulmonary Nodules in Chest Radiograph. J Clin Imaging Sci 2017; 7:8. [PMID: 28299236 PMCID: PMC5341301 DOI: 10.4103/jcis.jcis_75_16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [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: 08/17/2016] [Accepted: 01/23/2017] [Indexed: 11/30/2022] Open
Abstract
Aim: The most ubiquitous chest diagnostic method is the chest radiograph. A common radiographic finding, quite often incidental, is the nodular pulmonary lesion. The detection of small lesions out of complex parenchymal structure is a daily clinical challenge. In this study, we investigate the efficacy of the computer-aided detection (CAD) software package SoftView™ 2.4A for bone suppression and OnGuard™ 5.2 (Riverain Technologies, Miamisburg, OH, USA) for automated detection of pulmonary nodules in chest radiographs. Subjects and Methods: We retrospectively evaluated a dataset of 100 posteroanterior chest radiographs with pulmonary nodular lesions ranging from 5 to 85 mm. All nodules were confirmed with a consecutive computed tomography scan and histologically classified as 75% malignant. The number of detected lesions by observation in unprocessed images was compared to the number and dignity of CAD-detected lesions in bone-suppressed images (BSIs). Results: SoftView™ BSI does not affect the objective lesion-to-background contrast. OnGuard™ has a stand-alone sensitivity of 62% and specificity of 58% for nodular lesion detection in chest radiographs. The false positive rate is 0.88/image and the false negative (FN) rate is 0.35/image. From the true positive lesions, 20% were proven benign and 80% were malignant. FN lesions were 47% benign and 53% malignant. Conclusion: We conclude that CAD does not qualify for a stand-alone standard of diagnosis. The use of CAD accompanied with a critical radiological assessment of the software suggested pattern appears more realistic. Accordingly, it is essential to focus on studies assessing the quality-time-cost profile of real-time (as opposed to retrospective) CAD implementation in clinical diagnostics.
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Affiliation(s)
- Nikolaos Dellios
- Department of Experimental Radiology, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich-Schiller University, Jena, Germany; Institute of Radiology, Suedharz Hospital Nordhausen gGmbH, Nordhausen, Germany
| | - Ulf Teichgraeber
- Department of Experimental Radiology, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich-Schiller University, Jena, Germany
| | - Robert Chelaru
- Institute of Radiology, Suedharz Hospital Nordhausen gGmbH, Nordhausen, Germany
| | - Ansgar Malich
- Institute of Radiology, Suedharz Hospital Nordhausen gGmbH, Nordhausen, Germany
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6
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Albrecht A, Ivens S, Papageorgiou IE, Çalışkan G, Saiepour N, Brück W, Richter-Levin G, Heinemann U, Stork O. Shifts in excitatory/inhibitory balance by juvenile stress: A role for neuron-astrocyte interaction in the dentate gyrus. Glia 2016; 64:911-22. [PMID: 26875694 DOI: 10.1002/glia.22970] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [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: 01/29/2015] [Revised: 01/11/2016] [Accepted: 01/11/2016] [Indexed: 12/25/2022]
Abstract
Childhood trauma is a well-described risk factor for the development of stress-related psychopathology such as posttraumatic stress disorder or depression later in life. Childhood adversity can be modeled in rodents by juvenile stress (JS) protocols, resulting in impaired coping with stressful challenges in adulthood. In the current study, we investigated the long-lasting impact of JS on the expression of molecular factors for glutamate and γ-aminobutyric acid (GABA) uptake and turnover in sublayers of the dentate gyrus (DG) using laser microdissection and quantitative real-time polymerase chain reaction. We observed reduced mRNA expression levels after JS for factors mediating astrocytic glutamate and GABA uptake and degradation. These alterations were prominently observed in the dorsal but not ventral DG granule cell layer, indicating a lasting change in astrocytic GABA and glutamate metabolism that may affect dorsal DG network activity. Indeed, we observed increased inhibition and a lack of facilitation in response to paired-pulse stimulation at short interstimulus intervals in the dorsal DG after JS, while no alterations were evident in basal synaptic transmission or forms of long-term plasticity. The shift in paired-pulse response was mimicked by pharmacologically blocking the astrocytic GABA transporter GAT-3 in naïve animals. Accordingly, reduced expression levels of GAT-3 were confirmed at the protein level in the dorsal granule cell layer of rats stressed in juvenility. Together, these data demonstrate a lasting shift in the excitatory/inhibitory balance of dorsal DG network activity by JS that appears to be mediated by decreased GABA uptake into astrocytes.
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Affiliation(s)
- Anne Albrecht
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.,The Institute for the Study of Affective Neuroscience (ISAN), Haifa, Israel.,Institute of Biology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Sebastian Ivens
- Department of Psychiatry and Psychotherapy, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ismini E Papageorgiou
- Institute of Diagnostic and Interventional Neuroradiology, University of Göttingen, Göttingen, Germany
| | - Gürsel Çalışkan
- Institute of Biology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.,Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Nasrin Saiepour
- Institute of Neuropathology, University of Göttingen, Göttingen, Germany
| | - Wolfgang Brück
- Institute of Neuropathology, University of Göttingen, Göttingen, Germany
| | - Gal Richter-Levin
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.,The Institute for the Study of Affective Neuroscience (ISAN), Haifa, Israel.,Department of Psychology, University of Haifa, Haifa, Israel
| | - Uwe Heinemann
- Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Oliver Stork
- Institute of Biology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Universitätsplatz 2, Germany
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7
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Schneider J, Lewen A, Ta TT, Galow LV, Isola R, Papageorgiou IE, Kann O. A reliable model for gamma oscillations in hippocampal tissue. J Neurosci Res 2015; 93:1067-78. [PMID: 25808046 DOI: 10.1002/jnr.23590] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [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: 11/27/2014] [Revised: 02/16/2015] [Accepted: 02/27/2015] [Indexed: 12/13/2022]
Abstract
Gamma oscillations (30-100 Hz) reflect a fast brain rhythm that provides a fundamental mechanism of complex neuronal information processing in the hippocampus and in the neocortex in vivo. Gamma oscillations have been implicated in higher brain functions, such as sensory perception, motor activity, and memory formation. Experimental studies on synaptic transmission and bioenergetics underlying gamma oscillations have primarily used acute slices of the hippocampus. This study tests whether organotypic hippocampal slice cultures of the rat provide an alternative model for cortical gamma oscillations in vitro. Our findings are that 1) slice cultures feature well-preserved laminated architecture and neuronal morphology; 2) slice cultures of different maturation stages (7-28 days in vitro) reliably express gamma oscillations at about 40 Hz as induced by cholinergic (acetylcholine) or glutamatergic (kainate) receptor agonists; 3) the peak frequency of gamma oscillations depends on the temperature, with an increase of ∼ 3.5 Hz per degree Celsius for the range of 28-36 °C; 4) most slice cultures show persistent gamma oscillations for ∼ 1 hr during electrophysiological local field potential recordings, and later alterations may occur; and 5) in slice cultures, glucose at a concentration of 5 mM in the recording solution is sufficient to power gamma oscillations, and additional energy substrate supply with monocarboxylate metabolite lactate (2 mM) exclusively increases the peak frequency by ∼ 4 Hz. This study shows that organotypic hippocampal slice cultures provide a reliable model to study agonist-induced gamma oscillations at glucose levels near the physiological range.
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Affiliation(s)
- Justus Schneider
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences, University of Heidelberg, Heidelberg, Germany
| | - Andrea Lewen
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences, University of Heidelberg, Heidelberg, Germany
| | - Thuy-Truc Ta
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences, University of Heidelberg, Heidelberg, Germany
| | - Lukas V Galow
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences, University of Heidelberg, Heidelberg, Germany
| | - Raffaella Isola
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences, University of Heidelberg, Heidelberg, Germany
| | - Ismini E Papageorgiou
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences, University of Heidelberg, Heidelberg, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences, University of Heidelberg, Heidelberg, Germany
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8
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Galow LV, Schneider J, Lewen A, Ta TT, Papageorgiou IE, Kann O. Energy substrates that fuel fast neuronal network oscillations. Front Neurosci 2014; 8:398. [PMID: 25538552 PMCID: PMC4256998 DOI: 10.3389/fnins.2014.00398] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [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: 10/14/2014] [Accepted: 11/18/2014] [Indexed: 01/03/2023] Open
Abstract
Fast neuronal network oscillations in the gamma-frequency band (30–−100 Hz) provide a fundamental mechanism of complex neuronal information processing in the hippocampus and neocortex of mammals. Gamma oscillations have been implicated in higher brain functions such as sensory perception, motor activity, and memory formation. The oscillations emerge from precise synapse interactions between excitatory principal neurons such as pyramidal cells and inhibitory GABAergic interneurons, and they are associated with high energy expenditure. However, both energy substrates and metabolic pathways that are capable to power cortical gamma oscillations have been less defined. Here, we investigated the energy sources fueling persistent gamma oscillations in the CA3 subfield of organotypic hippocampal slice cultures of the rat. This preparation permits superior oxygen supply as well as fast application of glucose, glycolytic metabolites or drugs such as glycogen phosphorylase inhibitor during extracellular recordings of the local field potential. Our findings are: (i) gamma oscillations persist in the presence of glucose (10 mmol/L) for greater than 60 min in slice cultures while (ii) lowering glucose levels (2.5 mmol/L) significantly reduces the amplitude of the oscillation. (iii) Gamma oscillations are absent at low concentration of lactate (2 mmol/L). (iv) Gamma oscillations persist at high concentration (20 mmol/L) of either lactate or pyruvate, albeit showing significant reductions in the amplitude. (v) The breakdown of glycogen significantly delays the decay of gamma oscillations during glucose deprivation. However, when glucose is present, the turnover of glycogen is not essential to sustain gamma oscillations. Our study shows that fast neuronal network oscillations can be fueled by different energy-rich substrates, with glucose being most effective.
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Affiliation(s)
- Lukas V Galow
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg Heidelberg, Germany
| | - Justus Schneider
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg Heidelberg, Germany
| | - Andrea Lewen
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg Heidelberg, Germany
| | - Thuy-Truc Ta
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg Heidelberg, Germany
| | - Ismini E Papageorgiou
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg Heidelberg, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg Heidelberg, Germany
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9
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Kreis P, Hendricusdottir R, Kay L, Papageorgiou IE, van Diepen M, Mack T, Ryves J, Harwood A, Leslie NR, Kann O, Parsons M, Eickholt BJ. Phosphorylation of the actin binding protein Drebrin at S647 is regulated by neuronal activity and PTEN. PLoS One 2013; 8:e71957. [PMID: 23940795 PMCID: PMC3733845 DOI: 10.1371/journal.pone.0071957] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 07/04/2013] [Indexed: 01/24/2023] Open
Abstract
Defects in actin dynamics affect activity-dependent modulation of synaptic transmission and neuronal plasticity, and can cause cognitive impairment. A salient candidate actin-binding protein linking synaptic dysfunction to cognitive deficits is Drebrin (DBN). However, the specific mode of how DBN is regulated at the central synapse is largely unknown. In this study we identify and characterize the interaction of the PTEN tumor suppressor with DBN. Our results demonstrate that PTEN binds DBN and that this interaction results in the dephosphorylation of a site present in the DBN C-terminus--serine 647. PTEN and pS647-DBN segregate into distinct and complimentary compartments in neurons, supporting the idea that PTEN negatively regulates DBN phosphorylation at this site. We further demonstrate that neuronal activity increases phosphorylation of DBN at S647 in hippocampal neurons in vitro and in ex vivo hippocampus slices exhibiting seizure activity, potentially by inducing rapid dissociation of the PTEN:DBN complex. Our results identify a novel mechanism by which PTEN is required to maintain DBN phosphorylation at dynamic range and signifies an unusual regulation of an actin-binding protein linked to cognitive decline and degenerative conditions at the CNS synapse.
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Affiliation(s)
- Patricia Kreis
- MRC Centre for Developmental Neurobiology, King’s College London, London, United Kingdom
| | - Rita Hendricusdottir
- MRC Centre for Developmental Neurobiology, King’s College London, London, United Kingdom
| | - Louise Kay
- MRC Centre for Developmental Neurobiology, King’s College London, London, United Kingdom
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Ismini E. Papageorgiou
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Michiel van Diepen
- MRC Centre for Developmental Neurobiology, King’s College London, London, United Kingdom
- Novartis Pharmaceuticals UK Limited, Horsham, United Kingdom
| | - Till Mack
- Cluster of Excellence NeuroCure and Institute of Biochemistry, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jonny Ryves
- Cardiff School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Adrian Harwood
- Cardiff School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | | | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Maddy Parsons
- The Randall Division of Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Britta J. Eickholt
- MRC Centre for Developmental Neurobiology, King’s College London, London, United Kingdom
- Cluster of Excellence NeuroCure and Institute of Biochemistry, Charité - Universitätsmedizin Berlin, Berlin, Germany
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10
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Kann O, Taubenberger N, Huchzermeyer C, Papageorgiou IE, Benninger F, Heinemann U, Kovács R. Muscarinic receptor activation determines the effects of store-operated Ca2+-entry on excitability and energy metabolism in pyramidal neurons. Cell Calcium 2012; 51:40-50. [DOI: 10.1016/j.ceca.2011.10.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 10/14/2011] [Accepted: 10/19/2011] [Indexed: 10/15/2022]
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11
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Papageorgiou IE, Gabriel S, Fetani AF, Kann O, Heinemann U. Redistribution of astrocytic glutamine synthetase in the hippocampus of chronic epileptic rats. Glia 2011; 59:1706-18. [DOI: 10.1002/glia.21217] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 06/16/2011] [Indexed: 01/01/2023]
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