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Bullmann T, Stucki C, Kaiser N, Ziebarth K. [Fractures of the lateral condyle of the humerus in children : High risk of secondary dislocation with conservative treatment]. Unfallchirurgie (Heidelb) 2024:10.1007/s00113-024-01432-2. [PMID: 38649639 DOI: 10.1007/s00113-024-01432-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/06/2024] [Indexed: 04/25/2024]
Abstract
BACKGROUND Fractures of the lateral condyle of the humerus in children are articular fractures with difficult diagnostics due to the incompletely ossified elbow joint. The aim of this study was to evaluate the method of treatment at initial presentation and to analyze the frequency of subsequent displacement during follow-up. MATERIAL AND METHOD Retrospective analysis of the frequency of primary fracture dislocation and subsequent displacement of fractures of the lateral condyle of the humerus in children under 16 years of age between 2004 and 2021. Conventional radiographs in two planes at the time of the accident and in the follow-up after 5-7 days were evaluated. RESULTS A total of 285 fractures of the lateral condyle of the humerus were evaluated. The average age was 5.3 years. Of the fractures 109 (38.3%) were directly surgically treated in cases of primary displacement and 176 fractures (61.7%) were not primarily displaced and were initially treated conservatively. During follow-up, subsequent displacement was evident in 46 fractures (26.1%). A total of 130 fractures (45.6%) were treated conservatively and 155 fractures (54.4%) were treated surgically using open joint visualization and screw osteosynthesis or K‑wire osteosynthesis. CONCLUSION Fractures of the lateral condyle of the humerus occur more frequently in a certain age group and require targeted radiological diagnostics. Nondisplaced fractures can be treated conservatively but essential radiological follow-up shows a high number of subsequent displacements, so that open surgical stabilization is often necessary.
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Affiliation(s)
- T Bullmann
- Abteilung Kinderorthopädie, Kinderchirurgische Universitätsklinik, Inselspital Bern, Freiburgstraße 15, 3010, Bern, Schweiz.
| | - C Stucki
- Abteilung Kinderorthopädie, Kinderchirurgische Universitätsklinik, Inselspital Bern, Freiburgstraße 15, 3010, Bern, Schweiz
| | - N Kaiser
- Abteilung Kinderorthopädie, Kinderchirurgische Universitätsklinik, Inselspital Bern, Freiburgstraße 15, 3010, Bern, Schweiz
| | - K Ziebarth
- Abteilung Kinderorthopädie, Kinderchirurgische Universitätsklinik, Inselspital Bern, Freiburgstraße 15, 3010, Bern, Schweiz
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Rizalar FS, Lucht MT, Petzoldt A, Kong S, Sun J, Vines JH, Telugu NS, Diecke S, Kaas T, Bullmann T, Schmied C, Löwe D, King JS, Cho W, Hallermann S, Puchkov D, Sigrist SJ, Haucke V. Phosphatidylinositol 3,5-bisphosphate facilitates axonal vesicle transport and presynapse assembly. Science 2023; 382:223-230. [PMID: 37824668 PMCID: PMC10938084 DOI: 10.1126/science.adg1075] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 08/16/2023] [Indexed: 10/14/2023]
Abstract
Neurons relay information via specialized presynaptic compartments for neurotransmission. Unlike conventional organelles, the specialized apparatus characterizing the neuronal presynapse must form de novo. How the components for presynaptic neurotransmission are transported and assembled is poorly understood. Our results show that the rare late endosomal signaling lipid phosphatidylinositol 3,5-bisphosphate [PI(3,5)P2] directs the axonal cotransport of synaptic vesicle and active zone proteins in precursor vesicles in human neurons. Precursor vesicles are distinct from conventional secretory organelles, endosomes, and degradative lysosomes and are transported by coincident detection of PI(3,5)P2 and active ARL8 via kinesin KIF1A to the presynaptic compartment. Our findings identify a crucial mechanism that mediates the delivery of synaptic vesicle and active zone proteins to developing synapses.
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Affiliation(s)
- Filiz Sila Rizalar
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Max T. Lucht
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Astrid Petzoldt
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| | - Shuhan Kong
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Jiachen Sun
- Department of Chemistry, University of Illinois Chicago, Chicago, IL 60607, USA
| | - James H. Vines
- School of Biosciences, University of Sheffield, Firth Court Western Bank, Sheffield S10 2TN, UK
| | - Narasimha Swamy Telugu
- Max-Delbrück-Centrum für Molekulare Medizin (MDC), Technology Platform Pluripotent Stem Cells, Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Sebastian Diecke
- Max-Delbrück-Centrum für Molekulare Medizin (MDC), Technology Platform Pluripotent Stem Cells, Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Thomas Kaas
- Leipzig University, Carl-Ludwig-Institute of Physiology, Faculty of Medicine, 04103 Leipzig, Germany
| | - Torsten Bullmann
- Leipzig University, Carl-Ludwig-Institute of Physiology, Faculty of Medicine, 04103 Leipzig, Germany
| | - Christopher Schmied
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Delia Löwe
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Jason S. King
- School of Biosciences, University of Sheffield, Firth Court Western Bank, Sheffield S10 2TN, UK
| | - Wonhwa Cho
- Department of Chemistry, University of Illinois Chicago, Chicago, IL 60607, USA
| | - Stefan Hallermann
- Leipzig University, Carl-Ludwig-Institute of Physiology, Faculty of Medicine, 04103 Leipzig, Germany
| | - Dmytro Puchkov
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Stephan J. Sigrist
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
- Charité – Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
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3
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Steinke S, Kirmann T, Loi EA, Nerlich J, Weichard I, Kuhn P, Bullmann T, Ritzau-Jost A, Rizalar FS, Prüss H, Haucke V, Geis C, Hust M, Hallermann S. NMDA-receptor-Fc-fusion constructs neutralize anti-NMDA receptor antibodies. Brain 2023; 146:1812-1820. [PMID: 36866449 PMCID: PMC10151181 DOI: 10.1093/brain/awac497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 04/29/2022] [Revised: 11/15/2022] [Accepted: 12/12/2022] [Indexed: 03/04/2023] Open
Abstract
N-methyl-d-aspartate receptor (NMDAR) encephalitis is the most common subtype of autoimmune encephalitis characterized by a complex neuropsychiatric syndrome usually including memory impairment. Patients develop an intrathecal immune response against NMDARs with antibodies that presumably bind to the amino-terminal domain of the GluN1 subunit. The therapeutic response to immunotherapy is often delayed. Therefore, new therapeutic approaches for fast neutralization of NMDAR antibodies are needed. Here, we developed fusion constructs consisting of the Fc part of immunoglobulin G and the amino-terminal domains of either GluN1 or combinations of GluN1 with GluN2A or GluN2B. Surprisingly, both GluN1 and GluN2 subunits were required to generate high-affinity epitopes. The construct with both subunits efficiently prevented NMDAR binding of patient-derived monoclonal antibodies and of patient CSF containing high-titre NMDAR antibodies. Furthermore, it inhibited the internalization of NMDARs in rodent dissociated neurons and human induced pluripotent stem cell-derived neurons. Finally, the construct stabilized NMDAR currents recorded in rodent neurons and rescued memory defects in passive-transfer mouse models using intrahippocampal injections. Our results demonstrate that both GluN1 and GluN2B subunits contribute to the main immunogenic region of the NMDAR and provide a promising strategy for fast and specific treatment of NMDAR encephalitis, which could complement immunotherapy.
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Affiliation(s)
- Stephan Steinke
- Technische Universität Braunschweig, Institut für Biochemie, Biotechnologie und Bioinformatik, Department Medizinische Biotechnologie, Braunschweig 38106, Germany
| | - Toni Kirmann
- Faculty of Medicine, Carl-Ludwig-Institute of Physiology, Leipzig University, Leipzig 04103, Germany
| | - Eleonora A Loi
- Section Translational Neuroimmunology, Department for Neurology, Jena University Hospital, 07747 Jena, Germany
| | - Jana Nerlich
- Faculty of Medicine, Carl-Ludwig-Institute of Physiology, Leipzig University, Leipzig 04103, Germany
| | - Iron Weichard
- Faculty of Medicine, Carl-Ludwig-Institute of Physiology, Leipzig University, Leipzig 04103, Germany
| | | | - Torsten Bullmann
- Faculty of Medicine, Carl-Ludwig-Institute of Physiology, Leipzig University, Leipzig 04103, Germany
| | - Andreas Ritzau-Jost
- Faculty of Medicine, Carl-Ludwig-Institute of Physiology, Leipzig University, Leipzig 04103, Germany
| | - Filiz Sila Rizalar
- Department of Molecular Pharamcology and Cell Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany.,Faculty of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin 14195, Germany
| | - Harald Prüss
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin 10117, Germany.,Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Volker Haucke
- Department of Molecular Pharamcology and Cell Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany.,Faculty of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin 14195, Germany
| | - Christian Geis
- Section Translational Neuroimmunology, Department for Neurology, Jena University Hospital, 07747 Jena, Germany
| | - Michael Hust
- Technische Universität Braunschweig, Institut für Biochemie, Biotechnologie und Bioinformatik, Department Medizinische Biotechnologie, Braunschweig 38106, Germany
| | - Stefan Hallermann
- Faculty of Medicine, Carl-Ludwig-Institute of Physiology, Leipzig University, Leipzig 04103, Germany
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Hörning M, Bullmann T, Shibata T. Local Membrane Curvature Pins and Guides Excitable Membrane Waves in Chemotactic and Macropinocytic Cells - Biomedical Insights From an Innovative Simple Model. Front Cell Dev Biol 2021; 9:670943. [PMID: 34604207 PMCID: PMC8479871 DOI: 10.3389/fcell.2021.670943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 02/22/2021] [Accepted: 08/16/2021] [Indexed: 11/13/2022] Open
Abstract
PIP3 dynamics observed in membranes are responsible for the protruding edge formation in cancer and amoeboid cells. The mechanisms that maintain those PIP3 domains in three-dimensional space remain elusive, due to limitations in observation and analysis techniques. Recently, a strong relation between the cell geometry, the spatial confinement of the membrane, and the excitable signal transduction system has been revealed by Hörning and Shibata (2019) using a novel 3D spatiotemporal analysis methodology that enables the study of membrane signaling on the entire membrane (Hörning and Shibata, 2019). Here, using 3D spatial fluctuation and phase map analysis on actin polymerization inhibited Dictyostelium cells, we reveal a spatial asymmetry of PIP3 signaling on the membrane that is mediated by the contact perimeter of the plasma membrane — the spatial boundary around the cell-substrate adhered area on the plasma membrane. We show that the contact perimeter guides PIP3 waves and acts as a pinning site of PIP3 phase singularities, that is, the center point of spiral waves. The contact perimeter serves as a diffusion influencing boundary that is regulated by a cell size- and shape-dependent curvature. Our findings suggest an underlying mechanism that explains how local curvature can favor actin polymerization when PIP3 domains get pinned at the curved protrusive membrane edges in amoeboid cells.
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Affiliation(s)
- Marcel Hörning
- Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Stuttgart, Germany.,Laboratory for Physical Biology, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Torsten Bullmann
- Carl-Ludwig-Institute for Physiology, University of Leipzig, Leipzig, Germany
| | - Tatsuo Shibata
- Laboratory for Physical Biology, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
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Urakubo H, Bullmann T, Kubota Y, Oba S, Ishii S. UNI-EM: An Environment for Deep Neural Network-Based Automated Segmentation of Neuronal Electron Microscopic Images. Sci Rep 2019; 9:19413. [PMID: 31857624 PMCID: PMC6923391 DOI: 10.1038/s41598-019-55431-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 11/28/2019] [Indexed: 12/19/2022] Open
Abstract
Recently, there has been rapid expansion in the field of micro-connectomics, which targets the three-dimensional (3D) reconstruction of neuronal networks from stacks of two-dimensional (2D) electron microscopy (EM) images. The spatial scale of the 3D reconstruction increases rapidly owing to deep convolutional neural networks (CNNs) that enable automated image segmentation. Several research teams have developed their own software pipelines for CNN-based segmentation. However, the complexity of such pipelines makes their use difficult even for computer experts and impossible for non-experts. In this study, we developed a new software program, called UNI-EM, for 2D and 3D CNN-based segmentation. UNI-EM is a software collection for CNN-based EM image segmentation, including ground truth generation, training, inference, postprocessing, proofreading, and visualization. UNI-EM incorporates a set of 2D CNNs, i.e., U-Net, ResNet, HighwayNet, and DenseNet. We further wrapped flood-filling networks (FFNs) as a representative 3D CNN-based neuron segmentation algorithm. The 2D- and 3D-CNNs are known to demonstrate state-of-the-art level segmentation performance. We then provided two example workflows: mitochondria segmentation using a 2D CNN and neuron segmentation using FFNs. By following these example workflows, users can benefit from CNN-based segmentation without possessing knowledge of Python programming or CNN frameworks.
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Affiliation(s)
- Hidetoshi Urakubo
- Integrated Systems Biology Laboratory, Department of Systems Science, Graduate School of Informatics, Kyoto University, Yoshida-Honmachi 36-1, Sakyo-ku, Kyoto, 606-8501, Japan.
| | - Torsten Bullmann
- Integrated Systems Biology Laboratory, Department of Systems Science, Graduate School of Informatics, Kyoto University, Yoshida-Honmachi 36-1, Sakyo-ku, Kyoto, 606-8501, Japan.,Carl-Ludwig-Institute for Physiology, University Leipzig, Liebigstr. 27, 04103, Leipzig, Germany
| | - Yoshiyuki Kubota
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, 5-1 Myodaiji-Higashiyama, Okazaki, Aichi, 444-8787, Japan.,Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), 5-1 Myodaiji-Higashiyama, Okazaki, Aichi, 444-8787, Japan
| | - Shigeyuki Oba
- Integrated Systems Biology Laboratory, Department of Systems Science, Graduate School of Informatics, Kyoto University, Yoshida-Honmachi 36-1, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Shin Ishii
- Integrated Systems Biology Laboratory, Department of Systems Science, Graduate School of Informatics, Kyoto University, Yoshida-Honmachi 36-1, Sakyo-ku, Kyoto, 606-8501, Japan
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6
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Bullmann T, Radivojevic M, Huber ST, Deligkaris K, Hierlemann A, Frey U. Large-Scale Mapping of Axonal Arbors Using High-Density Microelectrode Arrays. Front Cell Neurosci 2019; 13:404. [PMID: 31555099 PMCID: PMC6742744 DOI: 10.3389/fncel.2019.00404] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [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: 05/23/2019] [Accepted: 08/20/2019] [Indexed: 12/30/2022] Open
Abstract
Understanding the role of axons in neuronal information processing is a fundamental task in neuroscience. Over the last years, sophisticated patch-clamp investigations have provided unexpected and exciting data on axonal phenomena and functioning, but there is still a need for methods to investigate full axonal arbors at sufficient throughput. Here, we present a new method for the simultaneous mapping of the axonal arbors of a large number of individual neurons, which relies on their extracellular signals that have been recorded with high-density microelectrode arrays (HD-MEAs). The segmentation of axons was performed based on the local correlation of extracellular signals. Comparison of the results with both, ground truth and receiver operator characteristics, shows that the new segmentation method outperforms previously used methods. Using a standard HD-MEA, we mapped the axonal arbors of 68 neurons in <6 h. The fully automated method can be extended to new generations of HD-MEAs with larger data output and is estimated to provide data of axonal arbors of thousands of neurons within recording sessions of a few hours.
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Affiliation(s)
- Torsten Bullmann
- RIKEN Quantitative Biology Center, RIKEN, Kobe, Japan.,Graduate School of Informatics, Kyoto University, Kyoto, Japan.,Carl Ludwig Institute for Physiology, University of Leipzig, Leipzig, Germany
| | - Milos Radivojevic
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | | | - Kosmas Deligkaris
- RIKEN Quantitative Biology Center, RIKEN, Kobe, Japan.,Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Andreas Hierlemann
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Urs Frey
- RIKEN Quantitative Biology Center, RIKEN, Kobe, Japan.,Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland.,MaxWell Biosystems AG, Basel, Switzerland
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Bullmann T, Feneberg E, Kretzschmann TP, Ogunlade V, Holzer M, Arendt T. Hibernation Impairs Odor Discrimination - Implications for Alzheimer's Disease. Front Neuroanat 2019; 13:69. [PMID: 31379517 PMCID: PMC6646461 DOI: 10.3389/fnana.2019.00069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [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: 02/26/2019] [Accepted: 06/21/2019] [Indexed: 11/13/2022] Open
Abstract
Reversible formation of PHF-like phosphorylated tau, an early feature of Alzheimer's disease (AD) was previously shown to occur in torpor during hibernation in the Golden hamster (Syrian hamster, Mesocricetus auratus). Here, we tackled the question to what extent hibernating Golden hamsters can serve as a model for the early stage of AD. During early AD, anosmia, the loss of olfactory function, is a common and typical feature. We, thus, investigated tau phosphorylation, synaptic plasticity and behavioral physiology of the olfactory system during hibernation. Tau was phosphorylated on several AD-relevant epitopes, and distribution of PHF-like phosphorylated tau in the olfactory bulb was quite similar to what is seen in AD. Tau phosphorylation was not associated with a destabilization of microtubules and did not lead to fibril formation. Previously, we observed a transient spine reduction in pyramidal cells in the hippocampus, which is correlated with the distribution of phosphorylated tau. Here we show that granule cells in the olfactory bulb are devoid of phosphorylated tau and maintain their spines number during torpor. No reduction of synaptic proteins was observed. However, hibernation did impair the recall performance in a two-odor discrimination task. We conclude that hibernation is associated with a specific olfactory memory deficit, which might not be attributed to the formation of PHF-like phosphorylated tau within the olfactory bulb. We discuss a possible involvement of modulatory input provided by cholinergic neurons in the basal forebrain, which are affected by hibernation.
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Affiliation(s)
- Torsten Bullmann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Emily Feneberg
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Tanja Petra Kretzschmann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Vera Ogunlade
- Department of Neuropathology, University of Leipzig, Leipzig, Germany
| | - Max Holzer
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Thomas Arendt
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
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Deligkaris K, Bullmann T, Frey U. Extracellularly Recorded Somatic and Neuritic Signal Shapes and Classification Algorithms for High-Density Microelectrode Array Electrophysiology. Front Neurosci 2016; 10:421. [PMID: 27683541 PMCID: PMC5021702 DOI: 10.3389/fnins.2016.00421] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [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: 07/11/2016] [Accepted: 08/29/2016] [Indexed: 11/13/2022] Open
Abstract
High-density microelectrode arrays (HDMEA) have been recently introduced to study principles of neural function at high spatial resolution. However, the exact nature of the experimentally observed extracellular action potentials (EAPs) is still incompletely understood. The soma, axon and dendrites of a neuron can all exhibit regenerative action potentials that could be sensed with HDMEA electrodes. Here, we investigate the contribution of distinct neuronal sources of activity in HDMEA recordings from low-density neuronal cultures. We recorded EAPs with HDMEAs having 11,011 electrodes and then fixed and immunostained the cultures with β3-tubulin for high-resolution fluorescence imaging. Immunofluorescence images overlaid with the activity maps showed EAPs both at neuronal somata and distal neurites. Neuritic EAPs had mostly narrow triphasic shapes, consisting of a positive, a pronounced negative peak and a second positive peak. EAPs near somata had wide monophasic or biphasic shapes with a main negative peak, and following optional positive peak. We show that about 86% of EAP recordings consist of somatic spikes, while the remaining 14% represent neuritic spikes. Furthermore, the adaptation of the waveform shape during bursts of these neuritic spikes suggested that they originate from axons, rather than from dendrites. Our study improves the understanding of HDMEA signals and can aid in the identification of the source of EAPs.
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Affiliation(s)
- Kosmas Deligkaris
- RIKEN Quantitative Biology Center, RIKENKobe, Japan; Graduate School of Frontier Biosciences, Osaka UniversityOsaka, Japan
| | | | - Urs Frey
- RIKEN Quantitative Biology Center, RIKENKobe, Japan; Graduate School of Frontier Biosciences, Osaka UniversityOsaka, Japan; Department of Biosystems Science and Engineering, ETH ZurichBasel, Switzerland
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Bullmann T, Seeger G, Stieler J, Hanics J, Reimann K, Kretzschmann TP, Hilbrich I, Holzer M, Alpár A, Arendt T. Tau phosphorylation-associated spine regression does not impair hippocampal-dependent memory in hibernating golden hamsters. Hippocampus 2015; 26:301-18. [DOI: 10.1002/hipo.22522] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 08/12/2015] [Accepted: 08/31/2015] [Indexed: 01/12/2023]
Affiliation(s)
- Torsten Bullmann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
- Frey Initiative Research Unit, RIKEN Quantitative Biology Center; Japan
| | - Gudrun Seeger
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Jens Stieler
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - János Hanics
- MTA-SE NAP B Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences; Budapest Hungary
- Department of Anatomy; Semmelweis University; Budapest Hungary
| | - Katja Reimann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Tanja Petra Kretzschmann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Isabel Hilbrich
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Max Holzer
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
| | - Alán Alpár
- MTA-SE NAP B Research Group of Experimental Neuroanatomy and Developmental Biology, Hungarian Academy of Sciences; Budapest Hungary
- Department of Anatomy; Semmelweis University; Budapest Hungary
| | - Thomas Arendt
- Department of Molecular and Cellular Mechanisms of Neurodegeneration; Paul Flechsig Institute of Brain Research, University of Leipzig; Leipzig Germany
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Bullmann T, Arendt T, Frey U, Hanashima C. A transportable, inexpensive electroporator for in utero electroporation. Dev Growth Differ 2015; 57:369-377. [PMID: 25988525 DOI: 10.1111/dgd.12216] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [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: 03/09/2015] [Revised: 03/31/2015] [Accepted: 04/08/2015] [Indexed: 01/14/2023]
Abstract
Electroporation is a useful technique to study gene function during development but its broad application is hampered due to the expensive equipment needed. We describe the construction of a transportable, simple and inexpensive electroporator delivering square pulses with varying length and amplitude. The device was successfully used for in utero electroporation in mouse with a performance comparable to that of commercial products.
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Affiliation(s)
- Torsten Bullmann
- Frey Initiative Research Unit, RIKEN Quantitative Biology Center, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan.,Laboratory for Neocortical Development, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan.,Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstraβe 19, 04103, Leipzig, Germany
| | - Thomas Arendt
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute of Brain Research, University of Leipzig, Liebigstraβe 19, 04103, Leipzig, Germany
| | - Urs Frey
- Frey Initiative Research Unit, RIKEN Quantitative Biology Center, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
| | - Carina Hanashima
- Laboratory for Neocortical Development, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan
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Obien MEJ, Deligkaris K, Bullmann T, Bakkum DJ, Frey U. Revealing neuronal function through microelectrode array recordings. Front Neurosci 2015; 8:423. [PMID: 25610364 PMCID: PMC4285113 DOI: 10.3389/fnins.2014.00423] [Citation(s) in RCA: 296] [Impact Index Per Article: 32.9] [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: 10/07/2014] [Accepted: 12/03/2014] [Indexed: 12/26/2022] Open
Abstract
Microelectrode arrays and microprobes have been widely utilized to measure neuronal activity, both in vitro and in vivo. The key advantage is the capability to record and stimulate neurons at multiple sites simultaneously. However, unlike the single-cell or single-channel resolution of intracellular recording, microelectrodes detect signals from all possible sources around every sensor. Here, we review the current understanding of microelectrode signals and the techniques for analyzing them. We introduce the ongoing advancements in microelectrode technology, with focus on achieving higher resolution and quality of recordings by means of monolithic integration with on-chip circuitry. We show how recent advanced microelectrode array measurement methods facilitate the understanding of single neurons as well as network function.
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Affiliation(s)
| | - Kosmas Deligkaris
- RIKEN Quantitative Biology Center, RIKEN Kobe, Japan ; Graduate School of Frontier Biosciences, Osaka University Osaka, Japan
| | | | - Douglas J Bakkum
- Department of Biosystems Science and Engineering, ETH Zurich Basel, Switzerland
| | - Urs Frey
- RIKEN Quantitative Biology Center, RIKEN Kobe, Japan ; Graduate School of Frontier Biosciences, Osaka University Osaka, Japan ; Department of Biosystems Science and Engineering, ETH Zurich Basel, Switzerland
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Arendt T, Bullmann T. Neuronal plasticity in hibernation and the proposed role of the microtubule-associated protein tau as a "master switch" regulating synaptic gain in neuronal networks. Am J Physiol Regul Integr Comp Physiol 2013; 305:R478-89. [PMID: 23824962 DOI: 10.1152/ajpregu.00117.2013] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present paper provides an overview of adaptive changes in brain structure and learning abilities during hibernation as a behavioral strategy used by several mammalian species to minimize energy expenditure under current or anticipated inhospitable environmental conditions. One cellular mechanism that contributes to the regulated suppression of metabolism and thermogenesis during hibernation is reversible phosphorylation of enzymes and proteins, which limits rates of flux through metabolic pathways. Reversible phosphorylation during hibernation also affects synaptic membrane proteins, a process known to be involved in synaptic plasticity. This mechanism of reversible protein phosphorylation also affects the microtubule-associated protein tau, thereby generating a condition that in the adult human brain is associated with aggregation of tau protein to paired helical filaments (PHFs), as observed in Alzheimer's disease. Here, we put forward the concept that phosphorylation of tau is a neuroprotective mechanism to escape NMDA-mediated hyperexcitability of neurons that would otherwise occur during slow gradual cooling of the brain. Phosphorylation of tau and its subsequent targeting to subsynaptic sites might, thus, work as a kind of "master switch," regulating NMDA receptor-mediated synaptic gain in a wide array of neuronal networks, thereby enabling entry into torpor. If this condition lasts too long, however, it may eventually turn into a pathological trigger, driving a cascade of events leading to neurodegeneration, as in Alzheimer's disease or other "tauopathies".
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Affiliation(s)
- Thomas Arendt
- Paul Flechsig Institute of Brain Research, Universität Leipzig, Germany.
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Bullmann T, Härtig W, Holzer M, Arendt T. Expression of the embryonal isoform (0N/3R) of the microtubule-associated protein tau in the adult rat central nervous system. J Comp Neurol 2010; 518:2538-53. [PMID: 20503426 DOI: 10.1002/cne.22351] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Tau is a microtubule-associated protein expressed predominantly in neurons. The transcript of the tau gene is alternatively spliced. Resulting isoforms contain three or four microtubule-binding repeats. The shortest tau isoform contains only three repeats (3R) and is expressed at birth. Previous data on rodents suggested that this isoform is no longer expressed during adulthood. It is replaced by tau isoforms containing four repeats (4R). The adult 4R tau isoforms bind to microtubules with higher affinity than 3R tau isoforms. Therefore, this isoform switch may reflect a need for more dynamic microtubules during development. Recently, we observed in rats that the 3R tau isoform is transiently expressed in adult neurogenesis. Subsequently, we performed an immunohistochemical labeling of the 3R tau isoform on serial sections of the adult rat brain. Interestingly, the 3R tau isoform is not only expressed in neuronal precursor cells. It is also present in mature neurons of the olfactory bulb, magnocellular neurosecretory system, posterolateral hypothalamus, locus coeruleus, raphe nucleus, solitary nucleus, medial septum and diagonal band, olfactory tuberculus, and piriform/olfactory cortex. This expression pattern is similar to that observed for the polysialylated form of the neuronal cell adhesion molecule (PSA-NCAM) and the microtubule-associated proteins doublecortin and collapsin response mediating protein (CRMP-4/TUC-4/Ulip-1), which are also highly expressed during early development. The retention of a juvenile phenotype in some neurons might be associated with a functionally significant neuronal plasticity.
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Affiliation(s)
- Torsten Bullmann
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute of Brain Research, University of Leipzig, 04109 Leipzig, Germany.
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Bullmann T, Stevenson PA. Nitric Oxide as an Efferent Modulator of Circadian Pacemaker Neurones in the Eye of the Marine Mollusc Bulla gouldiana~!2008-04-11~!2008-06-27~!2008-08-26~! ACTA ACUST UNITED AC 2010. [DOI: 10.2174/1874336600801010018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Bullmann T, Holzer M, Mori H, Arendt T. Pattern of tau isoforms expression during development
in vivo. Int J Dev Neurosci 2009; 27:591-7. [DOI: 10.1016/j.ijdevneu.2009.06.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Revised: 05/19/2009] [Accepted: 06/09/2009] [Indexed: 01/18/2023] Open
Affiliation(s)
- Torsten Bullmann
- Paul Flechsig Institute of Brain ResearchDepartment of Cellular and Molecular Mechanisms of NeurodegenerationUniversity of LeipzigJahnallee 5904019LeipzigGermany
| | - Max Holzer
- Paul Flechsig Institute of Brain ResearchDepartment of Cellular and Molecular Mechanisms of NeurodegenerationUniversity of LeipzigJahnallee 5904019LeipzigGermany
| | - Hiroshi Mori
- Department of NeuroscienceGraduate School of MedicineOsaka City University1‐4‐3 AsahimachiAbenoku545‐8585OsakaJapan
| | - Thomas Arendt
- Paul Flechsig Institute of Brain ResearchDepartment of Cellular and Molecular Mechanisms of NeurodegenerationUniversity of LeipzigJahnallee 5904019LeipzigGermany
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Stieler JT, Bullmann T, Kohl F, Barnes BM, Arendt T. PHF-like tau phosphorylation in mammalian hibernation is not associated with p25-formation. J Neural Transm (Vienna) 2009; 116:345-50. [PMID: 19184336 DOI: 10.1007/s00702-008-0181-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Accepted: 12/19/2008] [Indexed: 01/03/2023]
Abstract
In Alzheimer's disease and related disorders, hyperphosphorylation of tau is associated with an increased activity of cyclin dependent kinase 5 (cdk5). Elevated cdk5 activity is thought to be due to the formation of p25 and thereby represents a critical element in the dysregulation of tau phosphorylation under pathological conditions. However, there is still a controversy regarding the correlation of p25 generation and tau pathology. Recently, we demonstrated physiological, paired helical filament-like tau phosphorylation that reversibly occurs in hibernating mammals. Here we used this model to test whether the tau phosphorylation in hibernation is associated with the formation of p25. Analysing brain material of arctic ground squirrels and Syrian hamsters we found no evidence for a hibernation dependent generation of p25. Hence, we suppose that phosphorylation of tau does not require the formation of p25. Instead we suggest that the truncation of p35 to p25 represents a characteristic of pathological alterations and may contribute to aggregation and deposition of hyperphosphorylated tau.
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Affiliation(s)
- Jens Thorsten Stieler
- Department of Molecular and Cellular Mechanisms of Neurodegeneration, Paul Flechsig Institute of Brain Research, University of Leipzig, Jahnallee 59, 04109, Leipzig, Germany.
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Härtig W, Stieler J, Boerema AS, Wolf J, Schmidt U, Weissfuss J, Bullmann T, Strijkstra AM, Arendt T. Hibernation model of tau phosphorylation in hamsters: selective vulnerability of cholinergic basal forebrain neurons - implications for Alzheimer's disease. Eur J Neurosci 2007; 25:69-80. [PMID: 17241268 DOI: 10.1111/j.1460-9568.2006.05250.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Neurofibrillar tangles made up of 'paired helical filaments' (PHFs) consisting of hyperphosphorylated microtubule-associated protein tau are major hallmarks of Alzheimer's disease (AD). Tangle formation selectively affects certain neuronal types and systematically progresses throughout numerous brain areas, which reflects a hierarchy of neuronal vulnerability and provides the basis for the neuropathological staging of disease severity. Mechanisms underlying this selective neuronal vulnerability are unknown. We showed previously that reversible PHF-like phosphorylation of tau occurs during obligate hibernation. Here we extend these findings to facultative hibernators such as Syrian hamsters (Mesocricetus auratus) forced into hibernation. In this model, we showed in the basal forebrain projection system that cholinergic neurons are selectively affected by PHF-like phosphorylated tau, while gamma-aminobutyric acid (GABA)ergic neurons are largely spared, which shows strong parallels to the situation in AD. Formation of PHF-tau in these neurons apparently does not affect their function as pacemaker for terminating hibernation. We conclude that although formation of PHF-like phosphorylated tau in the mammalian brain follows a certain hierarchy, affecting some neurons more frequently than others, it is not necessarily associated with impaired neuronal function and viability. This indicates a more general link between PHF-like phosphorylation of tau and the adaptation of neurons under conditions of a 'vita minima'.
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Affiliation(s)
- Wolfgang Härtig
- Department of Neurochemistry, Paul Flechsig Institute for Brain Research, University of Leipzig, Jahnallee 59, 04109 Leipzig, Germany.
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Bullmann T, de Silva R, Holzer M, Mori H, Arendt T. Expression of embryonic tau protein isoforms persist during adult neurogenesis in the hippocampus. Hippocampus 2007; 17:98-102. [PMID: 17183532 DOI: 10.1002/hipo.20255] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Tau is a microtubule-associated protein with a developmentally regulated expression of multiple isoforms. The neonatal isoform is devoid of two amino terminal inserts and contains only three instead of four microtubule-binding repeats (0N/3R-tau). We investigated the temporal expression pattern of 0N-tau and 3R-tau in the rat hippocampus. After the decline of 0N- and 3R-tau immunoreactivity during the postnatal development both isoforms remain highly expressed in a few cells residing beneath the granule cell layer. Coexpression of the polysialylated neuronal cell adhesion molecule, doublecortin, and incorporated bromodeoxyuridine showed that these cells are proliferating progenitor cells. In contrast mature granule cells express the adult tau protein isoform containing one aminoterminal insert domain (1N-tau). Therefore a shift in tau isoform expression takes place during adult neurogenesis, which might be related to migration, differentiation, and integration in the granule cell layer. A model for studying shifts in tau isoform expression in a defined subset of neurons might help to understand the etiology of tauopathies, when isoform composition is crucial for neurodegeneration, as in Pick's disease or FTDP-17.
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Affiliation(s)
- Torsten Bullmann
- Department of Neuroanatomy, Paul-Flechsig Institute of Brain Research, University of Leipzig, Leipzig, Germany
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