1
|
Clavet-Fournier V, Lee C, Wegner W, Brose N, Rhee J, Willig KI. Pre- and postsynaptic nanostructures increase in size and complexity after induction of long-term potentiation. iScience 2024; 27:108679. [PMID: 38213627 PMCID: PMC10783556 DOI: 10.1016/j.isci.2023.108679] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 11/09/2023] [Accepted: 12/05/2023] [Indexed: 01/13/2024] Open
Abstract
Synapses, specialized contact sites between neurons, are the fundamental elements of neuronal information transfer. Synaptic plasticity involves changes in synaptic morphology and the number of neurotransmitter receptors, and is thought to underlie learning and memory. However, it is not clear how these structural and functional changes are connected. We utilized time-lapse super-resolution STED microscopy of organotypic hippocampal brain slices and cultured neurons to visualize structural changes of the synaptic nano-organization of the postsynaptic scaffolding protein PSD95, the presynaptic scaffolding protein Bassoon, and the GluA2 subunit of AMPA receptors by chemically induced long-term potentiation (cLTP) at the level of single synapses. We found that the nano-organization of all three proteins increased in complexity and size after cLTP induction. The increase was largely synchronous, peaking at ∼60 min after stimulation. Therefore, both the size and complexity of individual pre- and post-synaptic nanostructures serve as substrates for tuning and determining synaptic strength.
Collapse
Affiliation(s)
- Valérie Clavet-Fournier
- Group of Optical Nanoscopy in Neuroscience, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Göttingen Graduate Center for Neurosciences, Biophysics, und Molecular Biosciences (GGNB), Göttingen, Germany
| | - ChungKu Lee
- Department of Molecular Neurobiology, Synaptic Physiology Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Waja Wegner
- Group of Optical Nanoscopy in Neuroscience, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - JeongSeop Rhee
- Department of Molecular Neurobiology, Synaptic Physiology Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Katrin I. Willig
- Group of Optical Nanoscopy in Neuroscience, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
| |
Collapse
|
2
|
Dzyubenko E, Willig KI, Yin D, Sardari M, Tokmak E, Labus P, Schmermund B, Hermann DM. Structural changes in perineuronal nets and their perforating GABAergic synapses precede motor coordination recovery post stroke. J Biomed Sci 2023; 30:76. [PMID: 37658339 PMCID: PMC10474719 DOI: 10.1186/s12929-023-00971-x] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 08/29/2023] [Indexed: 09/03/2023] Open
Abstract
BACKGROUND Stroke remains one of the leading causes of long-term disability worldwide, and the development of effective restorative therapies is hindered by an incomplete understanding of intrinsic brain recovery mechanisms. Growing evidence indicates that the brain extracellular matrix (ECM) has major implications for neuroplasticity. Here we explored how perineuronal nets (PNNs), the facet-like ECM layers surrounding fast-spiking interneurons, contribute to neurological recovery after focal cerebral ischemia in mice with and without induced stroke tolerance. METHODS We investigated the structural remodeling of PNNs after stroke using 3D superresolution stimulated emission depletion (STED) and structured illumination (SR-SIM) microscopy. Superresolution imaging allowed for the precise reconstruction of PNN morphology using graphs, which are mathematical constructs designed for topological analysis. Focal cerebral ischemia was induced by transient occlusion of the middle cerebral artery (tMCAO). PNN-associated synapses and contacts with microglia/macrophages were quantified using high-resolution confocal microscopy. RESULTS PNNs undergo transient structural changes after stroke allowing for the dynamic reorganization of GABAergic input to motor cortical L5 interneurons. The coherent remodeling of PNNs and their perforating inhibitory synapses precedes the recovery of motor coordination after stroke and depends on the severity of the ischemic injury. Morphological alterations in PNNs correlate with the increased surface of contact between activated microglia/macrophages and PNN-coated neurons. CONCLUSIONS Our data indicate a novel mechanism of post stroke neuroplasticity involving the tripartite interaction between PNNs, synapses, and microglia/macrophages. We propose that prolonging PNN loosening during the post-acute period can extend the opening neuroplasticity window into the chronic stroke phase.
Collapse
Affiliation(s)
- Egor Dzyubenko
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, Hufelandstraße 55, 45122, Essen, Germany.
| | - Katrin I Willig
- Group of Optical Nanoscopy in Neuroscience, Max Planck Institute for Multidisciplinary Sciences, City Campus, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Dongpei Yin
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, Hufelandstraße 55, 45122, Essen, Germany
| | - Maryam Sardari
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, Hufelandstraße 55, 45122, Essen, Germany
| | - Erdin Tokmak
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, Hufelandstraße 55, 45122, Essen, Germany
| | - Patrick Labus
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, Hufelandstraße 55, 45122, Essen, Germany
| | - Ben Schmermund
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, Hufelandstraße 55, 45122, Essen, Germany
| | - Dirk M Hermann
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, Hufelandstraße 55, 45122, Essen, Germany.
| |
Collapse
|
3
|
Grimm E, van der Hoeven F, Sardella D, Willig KI, Engel U, Veits N, Engel R, Cavalcanti-Adam EA, Bestvater F, Bordoni L, Jennemann R, Schönig K, Schiessl IM, Sandhoff R. A Clathrin light chain A reporter mouse for in vivo imaging of endocytosis. PLoS One 2022; 17:e0273660. [PMID: 36149863 PMCID: PMC9506643 DOI: 10.1371/journal.pone.0273660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 12/16/2021] [Accepted: 08/13/2022] [Indexed: 11/20/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) is one of the best studied cellular uptake pathways and its contributions to nutrient uptake, receptor signaling, and maintenance of the lipid membrane homeostasis have been already elucidated. Today, we still have a lack of understanding how the different components of this pathway cooperate dynamically in vivo. Therefore, we generated a reporter mouse model for CME by fusing eGFP endogenously in frame to clathrin light chain a (Clta) to track endocytosis in living mice. The fusion protein is expressed in all tissues, but in a cell specific manner, and can be visualized using fluorescence microscopy. Recruitment to nanobeads recorded by TIRF microscopy validated the functionality of the Clta-eGFP reporter. With this reporter model we were able to track the dynamics of Alexa594-BSA uptake in kidneys of anesthetized mice using intravital 2-photon microscopy. This reporter mouse model is not only a suitable and powerful tool to track CME in vivo in genetic or disease mouse models it can also help to shed light into the differential roles of the two clathrin light chain isoforms in health and disease.
Collapse
Affiliation(s)
- Elisabeth Grimm
- Lipid Pathobiochemistry Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
- * E-mail: (EG); (RS)
| | | | - Donato Sardella
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Katrin I. Willig
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
- Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Ulrike Engel
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
- Nikon Imaging Center at Heidelberg University and Centre of Organismal Studies (COS), Bioquant, Heidelberg, Germany
| | - Nisha Veits
- Department of Cellular Biophysics, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Robert Engel
- Lipid Pathobiochemistry Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | | | - Felix Bestvater
- Light Microscopy Core Facility, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Luca Bordoni
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Richard Jennemann
- Lipid Pathobiochemistry Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kai Schönig
- Department of Molecular Biology, Central Institute of Mental Health, Mannheim, Germany
| | | | - Roger Sandhoff
- Lipid Pathobiochemistry Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
- * E-mail: (EG); (RS)
| |
Collapse
|
4
|
Willig KI. In vivo super-resolution of the brain – How to visualize the hidden nanoplasticity? iScience 2022; 25:104961. [PMID: 36093060 PMCID: PMC9449647 DOI: 10.1016/j.isci.2022.104961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Super-resolution fluorescence microscopy has entered most biological laboratories worldwide and its benefit is undisputable. Its application to brain imaging, for example in living mice, enables the study of sub-cellular structural plasticity and brain function directly in a living mammal. The demands of brain imaging on the different super-resolution microscopy techniques (STED, RESOLFT, SIM, ISM) and labeling strategies are discussed here as well as the challenges of the required cranial window preparation. Applications of super-resolution in the anesthetized mouse brain enlighten the stability and plasticity of synaptic nanostructures. These studies show the potential of in vivo super-resolution imaging and justify its application more widely in vivo to investigate the role of nanostructures in memory and learning.
Collapse
|
5
|
Wegner W, Steffens H, Gregor C, Wolf F, Willig KI. Environmental enrichment enhances patterning and remodeling of synaptic nanoarchitecture as revealed by STED nanoscopy. eLife 2022; 11:73603. [PMID: 35195066 PMCID: PMC8903838 DOI: 10.7554/elife.73603] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [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: 09/03/2021] [Accepted: 02/22/2022] [Indexed: 12/04/2022] Open
Abstract
Synaptic plasticity underlies long-lasting structural and functional changes to brain circuitry and its experience-dependent remodeling can be fundamentally enhanced by environmental enrichment. It is however unknown, whether and how the environmental enrichment alters the morphology and dynamics of individual synapses. Here, we present a virtually crosstalk-free two-color in vivo stimulated emission depletion (STED) microscope to simultaneously superresolve the dynamics of endogenous PSD95 of the post-synaptic density and spine geometry in the mouse cortex. In general, the spine head geometry and PSD95 assemblies were highly dynamic, their changes depended linearly on their original size but correlated only mildly. With environmental enrichment, the size distributions of PSD95 and spine head sizes were sharper than in controls, indicating that synaptic strength is set more uniformly. The topography of the PSD95 nanoorganization was more dynamic after environmental enrichment; changes in size were smaller but more correlated than in mice housed in standard cages. Thus, two-color in vivo time-lapse imaging of synaptic nanoorganization uncovers a unique synaptic nanoplasticity associated with the enhanced learning capabilities under environmental enrichment.
Collapse
Affiliation(s)
- Waja Wegner
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
| | - Heinz Steffens
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
| | - Carola Gregor
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Fred Wolf
- Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
| | - Katrin I Willig
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
| |
Collapse
|
6
|
Kuljis DA, Micheva KD, Ray A, Wegner W, Bowman R, Madison DV, Willig KI, Barth AL. Gephyrin-Lacking PV Synapses on Neocortical Pyramidal Neurons. Int J Mol Sci 2021; 22:ijms221810032. [PMID: 34576197 PMCID: PMC8467468 DOI: 10.3390/ijms221810032] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/01/2021] [Accepted: 09/07/2021] [Indexed: 11/26/2022] Open
Abstract
Gephyrin has long been thought of as a master regulator for inhibitory synapses, acting as a scaffold to organize γ-aminobutyric acid type A receptors (GABAARs) at the post-synaptic density. Accordingly, gephyrin immunostaining has been used as an indicator of inhibitory synapses; despite this, the pan-synaptic localization of gephyrin to specific classes of inhibitory synapses has not been demonstrated. Genetically encoded fibronectin intrabodies generated with mRNA display (FingRs) against gephyrin (Gephyrin.FingR) reliably label endogenous gephyrin, and can be tagged with fluorophores for comprehensive synaptic quantitation and monitoring. Here we investigated input- and target-specific localization of gephyrin at a defined class of inhibitory synapse, using Gephyrin.FingR proteins tagged with EGFP in brain tissue from transgenic mice. Parvalbumin-expressing (PV) neuron presynaptic boutons labeled using Cre- dependent synaptophysin-tdTomato were aligned with postsynaptic Gephyrin.FingR puncta. We discovered that more than one-third of PV boutons adjacent to neocortical pyramidal (Pyr) cell somas lack postsynaptic gephyrin labeling. This finding was confirmed using correlative fluorescence and electron microscopy. Our findings suggest some inhibitory synapses may lack gephyrin. Gephyrin-lacking synapses may play an important role in dynamically regulating cell activity under different physiological conditions.
Collapse
Affiliation(s)
- Dika A. Kuljis
- Center for the Neural Basis of Cognition, Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA; (D.A.K.); (A.R.); (R.B.)
| | - Kristina D. Micheva
- Department of Molecular and Cellular Physiology, Stanford University, Palo Alto, CA 94304, USA; (K.D.M.); (D.V.M.)
| | - Ajit Ray
- Center for the Neural Basis of Cognition, Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA; (D.A.K.); (A.R.); (R.B.)
| | - Waja Wegner
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, 37075 Göttingen, Germany; (W.W.); (K.I.W.)
- Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Ryan Bowman
- Center for the Neural Basis of Cognition, Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA; (D.A.K.); (A.R.); (R.B.)
| | - Daniel V. Madison
- Department of Molecular and Cellular Physiology, Stanford University, Palo Alto, CA 94304, USA; (K.D.M.); (D.V.M.)
| | - Katrin I. Willig
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, 37075 Göttingen, Germany; (W.W.); (K.I.W.)
- Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Alison L. Barth
- Center for the Neural Basis of Cognition, Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA; (D.A.K.); (A.R.); (R.B.)
- Correspondence: ; Tel.: +1-412-268-1198
| |
Collapse
|
7
|
Willig KI, Wegner W, Müller A, Calvet-Fournier V, Steffens H. Multi-label in vivo STED microscopy by parallelized switching of reversibly switchable fluorescent proteins. Cell Rep 2021; 35:109192. [PMID: 34077731 DOI: 10.1016/j.celrep.2021.109192] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/08/2021] [Accepted: 05/07/2021] [Indexed: 01/07/2023] Open
Abstract
Despite the tremendous success of super-resolution microscopy, multi-color in vivo applications are still rare. Here we present live-cell multi-label STED microscopy in vivo and in vitro by combining spectrally separated excitation and detection with temporal sequential imaging of reversibly switchable fluorescent proteins (RSFPs). Triple-label STED microscopy resolves pre- and postsynaptic nano-organizations in vivo in mouse visual cortex employing EGFP, Citrine, and the RSFP rsEGP2. Combining the positive and negative switching RSFPs Padron and Dronpa-M159T enables dual-label STED microscopy. All labels are recorded quasi-simultaneously by parallelized on- and off-switching of the RSFPs within the fast-scanning axis. Depletion is performed by a single STED beam so that all channels automatically co-align. Such an addition of a second or third marker merely requires a switching laser, minimizing setup complexity. Our technique enhances in vivo STED microscopy, making it a powerful tool for studying multiple synaptic nano-organizations or the tripartite synapse in vivo.
Collapse
Affiliation(s)
- Katrin I Willig
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany; Max Planck Institute of Experimental Medicine, Göttingen, Germany; Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.
| | - Waja Wegner
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany; Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Antonia Müller
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany; Max Planck Institute of Experimental Medicine, Göttingen, Germany; Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
| | - Valérie Calvet-Fournier
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany; Max Planck Institute of Experimental Medicine, Göttingen, Germany; Göttingen Graduate Center for Neurosciences, Biophysics, und Molecular Biosciences (GGNB), Göttingen, Germany
| | - Heinz Steffens
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany; Max Planck Institute of Experimental Medicine, Göttingen, Germany
| |
Collapse
|
8
|
Ambrozkiewicz MC, Borisova E, Schwark M, Ripamonti S, Schaub T, Smorodchenko A, Weber AI, Rhee HJ, Altas B, Yilmaz R, Mueller S, Piepkorn L, Horan ST, Straussberg R, Zaqout S, Jahn O, Dere E, Rosário M, Boehm-Sturm P, Borck G, Willig KI, Rhee J, Tarabykin V, Kawabe H. The murine ortholog of Kaufman oculocerebrofacial syndrome protein Ube3b regulates synapse number by ubiquitinating Ppp3cc. Mol Psychiatry 2021; 26:1980-1995. [PMID: 32249816 DOI: 10.1038/s41380-020-0714-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 02/21/2020] [Accepted: 03/11/2020] [Indexed: 12/11/2022]
Abstract
Kaufman oculocerebrofacial syndrome (KOS) is a severe autosomal recessive disorder characterized by intellectual disability, developmental delays, microcephaly, and characteristic dysmorphisms. Biallelic mutations of UBE3B, encoding for a ubiquitin ligase E3B are causative for KOS. In this report, we characterize neuronal functions of its murine ortholog Ube3b and show that Ube3b regulates dendritic branching in a cell-autonomous manner. Moreover, Ube3b knockout (KO) neurons exhibit increased density and aberrant morphology of dendritic spines, altered synaptic physiology, and changes in hippocampal circuit activity. Dorsal forebrain-specific Ube3b KO animals show impaired spatial learning, altered social interactions, and repetitive behaviors. We further demonstrate that Ube3b ubiquitinates the catalytic γ-subunit of calcineurin, Ppp3cc, the overexpression of which phenocopies Ube3b loss with regard to dendritic spine density. This work provides insights into the molecular pathologies underlying intellectual disability-like phenotypes in a genetically engineered mouse model.
Collapse
Affiliation(s)
- Mateusz C Ambrozkiewicz
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany. .,International Max Planck Research School for Neurosciences, Georg-August-Universität Göttingen, Griesebachstr. 5, 37077, Göttingen, Germany. .,Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany.
| | - Ekaterina Borisova
- Institute of Neuroscience, Lobachevsky University of Nizhny Novgorod, pr. Gagarina 24, Nizhny Novgorod, Russian Federation
| | - Manuela Schwark
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Silvia Ripamonti
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Theres Schaub
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Alina Smorodchenko
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - A Ioana Weber
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Hong Jun Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Bekir Altas
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany.,International Max Planck Research School for Neurosciences, Georg-August-Universität Göttingen, Griesebachstr. 5, 37077, Göttingen, Germany
| | - Rüstem Yilmaz
- Center for Rare Diseases (ZSE Ulm), Ulm University Hospital, Eythstraße 24, 89075, Ulm, Germany
| | - Susanne Mueller
- Department of Experimental Neurology and Center for Stroke Research, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.,NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Lars Piepkorn
- Proteomics Group, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Stephen T Horan
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Rachel Straussberg
- Institute of Child Neurology, Schneider's Children Medical Center, Petah Tikvah, Israel.,Sackler School of Medicine, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Sami Zaqout
- Basic Medical Science Department, College of Medicine, QU Health, Qatar University, Doha, Qatar
| | - Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Ekrem Dere
- Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Marta Rosário
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Philipp Boehm-Sturm
- Department of Experimental Neurology and Center for Stroke Research, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany.,NeuroCure Cluster of Excellence and Charité Core Facility 7T Experimental MRIs, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Guntram Borck
- Center for Rare Diseases (ZSE Ulm), Ulm University Hospital, Eythstraße 24, 89075, Ulm, Germany
| | - Katrin I Willig
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - JeongSeop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Victor Tarabykin
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany.,Institute of Neuroscience, Lobachevsky University of Nizhny Novgorod, pr. Gagarina 24, Nizhny Novgorod, Russian Federation
| | - Hiroshi Kawabe
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Str. 3, 37075, Göttingen, Germany. .,Division of Pathogenetic Signaling, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, 1-5-6 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan. .,Department of Gerontology, Laboratory of Molecular Life Science, Institute of Biomedical Research and Innovation, Foundation for Biomedical Research and Innovation at Kobe, 2-2 Minatojima-minamimachi Chuo-ku, Kobe, 650-0047, Japan.
| |
Collapse
|
9
|
Steffens H, Mott AC, Li S, Wegner W, Švehla P, Kan VWY, Wolf F, Liebscher S, Willig KI. Stable but not rigid: Chronic in vivo STED nanoscopy reveals extensive remodeling of spines, indicating multiple drivers of plasticity. Sci Adv 2021; 7:7/24/eabf2806. [PMID: 34108204 PMCID: PMC8189587 DOI: 10.1126/sciadv.abf2806] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/22/2021] [Indexed: 06/01/2023]
Abstract
Excitatory synapses on dendritic spines of pyramidal neurons are considered a central memory locus. To foster both continuous adaption and the storage of long-term information, spines need to be plastic and stable at the same time. Here, we advanced in vivo STED nanoscopy to superresolve distinct features of spines (head size and neck length/width) in mouse neocortex for up to 1 month. While LTP-dependent changes predict highly correlated modifications of spine geometry, we find both, uncorrelated and correlated dynamics, indicating multiple independent drivers of spine remodeling. The magnitude of this remodeling suggests substantial fluctuations in synaptic strength. Despite this high degree of volatility, all spine features exhibit persistent components that are maintained over long periods of time. Furthermore, chronic nanoscopy uncovers structural alterations in the cortex of a mouse model of neurodegeneration. Thus, at the nanoscale, stable dendritic spines exhibit a delicate balance of stability and volatility.
Collapse
Affiliation(s)
- Heinz Steffens
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
- Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Alexander C Mott
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
- Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Siyuan Li
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
- BioMedical Center, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Waja Wegner
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
- Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Pavel Švehla
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
- BioMedical Center, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Vanessa W Y Kan
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
- BioMedical Center, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Fred Wolf
- Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Max Planck Institute for Dynamics and Self-Organization; Campus Institute for Dynamics of Biological Networks, Göttingen, Germany
| | - Sabine Liebscher
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany.
- BioMedical Center, Faculty of Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Katrin I Willig
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany.
- Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
| |
Collapse
|
10
|
Steffens H, Wegner W, Willig KI. In vivo STED microscopy: A roadmap to nanoscale imaging in the living mouse. Methods 2020; 174:42-48. [DOI: 10.1016/j.ymeth.2019.05.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/15/2019] [Accepted: 05/21/2019] [Indexed: 11/28/2022] Open
|
11
|
Stahlberg MA, Ramakrishnan C, Willig KI, Boyden ES, Deisseroth K, Dean C. Investigating the feasibility of channelrhodopsin variants for nanoscale optogenetics. Neurophotonics 2019; 6:015007. [PMID: 30854405 PMCID: PMC6393647 DOI: 10.1117/1.nph.6.1.015007] [Citation(s) in RCA: 10] [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] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/05/2019] [Indexed: 06/09/2023]
Abstract
Optogenetics has revolutionized the study of circuit function in the brain, by allowing activation of specific ensembles of neurons by light. However, this technique has not yet been exploited extensively at the subcellular level. Here, we test the feasibility of a focal stimulation approach using stimulated emission depletion/reversible saturable optical fluorescence transitions-like illumination, whereby switchable light-gated channels are focally activated by a laser beam of one wavelength and deactivated by an overlapping donut-shaped beam of a different wavelength, confining activation to a center focal region. This method requires that activated channelrhodopsins are inactivated by overlapping illumination of a distinct wavelength and that photocurrents are large enough to be detected at the nanoscale. In tests of current optogenetic tools, we found that ChR2 C128A/H134R/T159C and CoChR C108S and C108S/D136A-activated with 405-nm light and inactivated by coillumination with 594-nm light-and C1V1 E122T/C167S-activated by 561-nm light and inactivated by 405-nm light-were most promising in terms of highest photocurrents and efficient inactivation with coillumination. Although further engineering of step-function channelrhodopsin variants with higher photoconductances will be required to employ this approach at the nanoscale, our findings provide a framework to guide future development of this technique.
Collapse
Affiliation(s)
- Markus A. Stahlberg
- European Neuroscience Institute, Trans-Synaptic Signaling Group, Goettingen, Germany
| | - Charu Ramakrishnan
- Stanford University, Howard Hughes Medical Institute, Department of Bioengineering, Department of Psychiatry, CNC Program, Stanford, California, United States
| | - Katrin I. Willig
- University Medical Center, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Goettingen, Germany
| | - Edward S. Boyden
- MIT Media Lab and McGovern Institute, Departments of Brain and Cognitive Science and Biological Engineering, Cambridge, Massachusetts, United States
| | - Karl Deisseroth
- Stanford University, Howard Hughes Medical Institute, Department of Bioengineering, Department of Psychiatry, CNC Program, Stanford, California, United States
| | - Camin Dean
- European Neuroscience Institute, Trans-Synaptic Signaling Group, Goettingen, Germany
| |
Collapse
|
12
|
Neef J, Urban NT, Ohn TL, Frank T, Jean P, Hell SW, Willig KI, Moser T. Quantitative optical nanophysiology of Ca 2+ signaling at inner hair cell active zones. Nat Commun 2018; 9:290. [PMID: 29348575 PMCID: PMC5773603 DOI: 10.1038/s41467-017-02612-y] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 12/14/2017] [Indexed: 12/17/2022] Open
Abstract
Ca2+ influx triggers the release of synaptic vesicles at the presynaptic active zone (AZ). A quantitative characterization of presynaptic Ca2+ signaling is critical for understanding synaptic transmission. However, this has remained challenging to establish at the required resolution. Here, we employ confocal and stimulated emission depletion (STED) microscopy to quantify the number (20-330) and arrangement (mostly linear 70 nm × 100-600 nm clusters) of Ca2+ channels at AZs of mouse cochlear inner hair cells (IHCs). Establishing STED Ca2+ imaging, we analyze presynaptic Ca2+ signals at the nanometer scale and find confined elongated Ca2+ domains at normal IHC AZs, whereas Ca2+ domains are spatially spread out at the AZs of bassoon-deficient IHCs. Performing 2D-STED fluorescence lifetime analysis, we arrive at estimates of the Ca2+ concentrations at stimulated IHC AZs of on average 25 µM. We propose that IHCs form bassoon-dependent presynaptic Ca2+-channel clusters of similar density but scalable length, thereby varying the number of Ca2+ channels amongst individual AZs.
Collapse
Affiliation(s)
- Jakob Neef
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37099, Göttingen, Germany.,Collaborative Research Center 889, University of Göttingen, 37075 Göttingen, Germany.,Bernstein Focus for Neurotechnology, University of Göttingen, 37075 Göttingen, Germany.,Synaptic Nanophysiology Group, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany
| | - Nicolai T Urban
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany. .,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, 37099 Göttingen, Germany.
| | - Tzu-Lun Ohn
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37099, Göttingen, Germany.,Collaborative Research Center 889, University of Göttingen, 37075 Göttingen, Germany.,Bernstein Focus for Neurotechnology, University of Göttingen, 37075 Göttingen, Germany
| | - Thomas Frank
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37099, Göttingen, Germany.,Friedrich Miescher Institute for Biomedical Research, 4058, Basel, Switzerland
| | - Philippe Jean
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37099, Göttingen, Germany
| | - Stefan W Hell
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, 37099 Göttingen, Germany
| | - Katrin I Willig
- Collaborative Research Center 889, University of Göttingen, 37075 Göttingen, Germany. .,Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany. .,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, 37099 Göttingen, Germany. .,Optical Nanoscopy in Neuroscience, University Medical Center Göttingen, 37099, Göttingen, Germany.
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37099, Göttingen, Germany. .,Collaborative Research Center 889, University of Göttingen, 37075 Göttingen, Germany. .,Bernstein Focus for Neurotechnology, University of Göttingen, 37075 Göttingen, Germany. .,Synaptic Nanophysiology Group, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany. .,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, 37099 Göttingen, Germany. .,Bernstein Center for Computational Neuroscience, University of Göttingen, 37075 Göttingen, Germany.
| |
Collapse
|
13
|
Wegner W, Mott AC, Grant SGN, Steffens H, Willig KI. In vivo STED microscopy visualizes PSD95 sub-structures and morphological changes over several hours in the mouse visual cortex. Sci Rep 2018; 8:219. [PMID: 29317733 PMCID: PMC5760696 DOI: 10.1038/s41598-017-18640-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 12/14/2017] [Indexed: 12/23/2022] Open
Abstract
The post-synaptic density (PSD) is an electron dense region consisting of ~1000 proteins, found at the postsynaptic membrane of excitatory synapses, which varies in size depending upon synaptic strength. PSD95 is an abundant scaffolding protein in the PSD and assembles a family of supercomplexes comprised of neurotransmitter receptors, ion channels, as well as signalling and structural proteins. We use superresolution STED (STimulated Emission Depletion) nanoscopy to determine the size and shape of PSD95 in the anaesthetised mouse visual cortex. Adult knock-in mice expressing eGFP fused to the endogenous PSD95 protein were imaged at time points from 1 min to 6 h. Superresolved large assemblies of PSD95 show different sub-structures; most large assemblies were ring-like, some horse-shoe or figure-8 shaped, and shapes were continuous or made up of nanoclusters. The sub-structure appeared stable during the shorter (minute) time points, but after 1 h, more than 50% of the large assemblies showed a change in sub-structure. Overall, these data showed a sub-morphology of large PSD95 assemblies which undergo changes within the 6 hours of observation in the anaesthetised mouse.
Collapse
Affiliation(s)
- Waja Wegner
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany.,Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.,Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Alexander C Mott
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany.,Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Seth G N Grant
- Genes to Cognition Program, Centre for Clinical Brain Sciences, Chancellor's Building, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Heinz Steffens
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany.,Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.,Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Katrin I Willig
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany. .,Collaborative Research Center 889, University of Göttingen, Göttingen, Germany. .,Max Planck Institute of Experimental Medicine, Göttingen, Germany.
| |
Collapse
|
14
|
Wegner W, Ilgen P, Gregor C, van Dort J, Mott AC, Steffens H, Willig KI. In vivo mouse and live cell STED microscopy of neuronal actin plasticity using far-red emitting fluorescent proteins. Sci Rep 2017; 7:11781. [PMID: 28924236 PMCID: PMC5603588 DOI: 10.1038/s41598-017-11827-4] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 08/30/2017] [Indexed: 12/30/2022] Open
Abstract
The study of proteins in dendritic processes within the living brain is mainly hampered by the diffraction limit of light. STED microscopy is so far the only far-field light microscopy technique to overcome the diffraction limit and resolve dendritic spine plasticity at superresolution (nanoscopy) in the living mouse. After having tested several far-red fluorescent proteins in cell culture we report here STED microscopy of the far-red fluorescent protein mNeptune2, which showed best results for our application to superresolve actin filaments at a resolution of ~80 nm, and to observe morphological changes of actin in the cortex of a living mouse. We illustrate in vivo far-red neuronal actin imaging in the living mouse brain with superresolution for time periods of up to one hour. Actin was visualized by fusing mNeptune2 to the actin labels Lifeact or Actin-Chromobody. We evaluated the concentration dependent influence of both actin labels on the appearance of dendritic spines; spine number was significantly reduced at high expression levels whereas spine morphology was normal at low expression.
Collapse
Affiliation(s)
- Waja Wegner
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
- Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Peter Ilgen
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
- Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Carola Gregor
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Joris van Dort
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
- Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Alexander C Mott
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
- Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Heinz Steffens
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
- Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Katrin I Willig
- Optical Nanoscopy in Neuroscience, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, Göttingen, Germany.
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany.
- Max Planck Institute of Experimental Medicine, Göttingen, Germany.
| |
Collapse
|
15
|
Belov VN, Mitronova GY, Bossi ML, Boyarskiy VP, Hebisch E, Geisler C, Kolmakov K, Wurm CA, Willig KI, Hell SW. Cover Picture: Masked Rhodamine Dyes of Five Principal Colors Revealed by Photolysis of a 2-Diazo-1-Indanone Caging Group: Synthesis, Photophysics, and Light Microscopy Applications (Chem. Eur. J. 41/2014). Chemistry 2014. [DOI: 10.1002/chem.201490170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
16
|
Belov VN, Mitronova GY, Bossi ML, Boyarskiy VP, Hebisch E, Geisler C, Kolmakov K, Wurm CA, Willig KI, Hell SW. Masked rhodamine dyes of five principal colors revealed by photolysis of a 2-diazo-1-indanone caging group: synthesis, photophysics, and light microscopy applications. Chemistry 2014; 20:13162-73. [PMID: 25196166 DOI: 10.1002/chem.201403316] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [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: 04/29/2014] [Indexed: 12/17/2022]
Abstract
Caged rhodamine dyes (Rhodamines NN) of five basic colors were synthesized and used as "hidden" markers in subdiffractional and conventional light microscopy. These masked fluorophores with a 2-diazo-1-indanone group can be irreversibly photoactivated, either by irradiation with UV- or violet light (one-photon process), or by exposure to intense red light (λ∼750 nm; two-photon mode). All dyes possess a very small 2-diazoketone caging group incorporated into the 2-diazo-1-indanone residue with a quaternary carbon atom (C-3) and a spiro-9H-xanthene fragment. Initially they are non-colored (pale yellow), non-fluorescent, and absorb at λ=330-350 nm (molar extinction coefficient (ε)≈10(4) M(-1) cm(-1)) with a band edge that extends to about λ=440 nm. The absorption and emission bands of the uncaged derivatives are tunable over a wide range (λ=511-633 and 525-653 nm, respectively). The unmasked dyes are highly colored and fluorescent (ε=3-8×10(4) M(-1) cm(-1) and fluorescence quantum yields (ϕ)=40-85% in the unbound state and in methanol). By stepwise and orthogonal protection of carboxylic and sulfonic acid groups a highly water-soluble caged red-emitting dye with two sulfonic acid residues was prepared. Rhodamines NN were decorated with amino-reactive N-hydroxysuccinimidyl ester groups, applied in aqueous buffers, easily conjugated with proteins, and readily photoactivated (uncaged) with λ=375-420 nm light or intense red light (λ=775 nm). Protein conjugates with optimal degrees of labeling (3-6) were prepared and uncaged with λ=405 nm light in aqueous buffer solutions (ϕ=20-38%). The photochemical cleavage of the masking group generates only molecular nitrogen. Some 10-40% of the non-fluorescent (dark) byproducts are also formed. However, they have low absorbance and do not quench the fluorescence of the uncaged dyes. Photoactivation of the individual molecules of Rhodamines NN (e.g., due to reversible or irreversible transition to a "dark" non-emitting state or photobleaching) provides multicolor images with subdiffractional optical resolution. The applicability of these novel caged fluorophores in super-resolution optical microscopy is exemplified.
Collapse
Affiliation(s)
- Vladimir N Belov
- NanoBiophotonics Department, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen (Germany), Fax: (+49) 551-201-2505.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Willig KI, Steffens H, Gregor C, Herholt A, Rossner MJ, Hell SW. Nanoscopy of filamentous actin in cortical dendrites of a living mouse. Biophys J 2014; 106:L01-3. [PMID: 24411266 DOI: 10.1016/j.bpj.2013.11.1119] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 11/12/2013] [Accepted: 11/13/2013] [Indexed: 01/03/2023] Open
Abstract
We demonstrate superresolution fluorescence microscopy (nanoscopy) of protein distributions in a mammalian brain in vivo. Stimulated emission depletion microscopy reveals the morphology of the filamentous actin in dendritic spines down to 40 μm in the molecular layer of the visual cortex of an anesthetized mouse. Consecutive recordings at 43-70 nm resolution reveal dynamical changes in spine morphology.
Collapse
Affiliation(s)
- Katrin I Willig
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany; Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany.
| | - Heinz Steffens
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Carola Gregor
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Alexander Herholt
- Department of Molecular Neurobiology and Department of Psychiatry, Ludwig-Maximilians-University, München, Germany
| | - Moritz J Rossner
- Department of Molecular Neurobiology and Department of Psychiatry, Ludwig-Maximilians-University, München, Germany
| | - Stefan W Hell
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany; Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany.
| |
Collapse
|
18
|
Agarwal A, Zhang M, Trembak-Duff I, Unterbarnscheidt T, Radyushkin K, Dibaj P, Martins de Souza D, Boretius S, Brzózka MM, Steffens H, Berning S, Teng Z, Gummert MN, Tantra M, Guest PC, Willig KI, Frahm J, Hell SW, Bahn S, Rossner MJ, Nave KA, Ehrenreich H, Zhang W, Schwab MH. Dysregulated expression of neuregulin-1 by cortical pyramidal neurons disrupts synaptic plasticity. Cell Rep 2014; 8:1130-45. [PMID: 25131210 DOI: 10.1016/j.celrep.2014.07.026] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 04/04/2014] [Accepted: 07/16/2014] [Indexed: 12/17/2022] Open
Abstract
Neuregulin-1 (NRG1) gene variants are associated with increased genetic risk for schizophrenia. It is unclear whether risk haplotypes cause elevated or decreased expression of NRG1 in the brains of schizophrenia patients, given that both findings have been reported from autopsy studies. To study NRG1 functions in vivo, we generated mouse mutants with reduced and elevated NRG1 levels and analyzed the impact on cortical functions. Loss of NRG1 from cortical projection neurons resulted in increased inhibitory neurotransmission, reduced synaptic plasticity, and hypoactivity. Neuronal overexpression of cysteine-rich domain (CRD)-NRG1, the major brain isoform, caused unbalanced excitatory-inhibitory neurotransmission, reduced synaptic plasticity, abnormal spine growth, altered steady-state levels of synaptic plasticity-related proteins, and impaired sensorimotor gating. We conclude that an "optimal" level of NRG1 signaling balances excitatory and inhibitory neurotransmission in the cortex. Our data provide a potential pathomechanism for impaired synaptic plasticity and suggest that human NRG1 risk haplotypes exert a gain-of-function effect.
Collapse
Affiliation(s)
- Amit Agarwal
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21025, USA
| | - Mingyue Zhang
- Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, 48149 Muenster Germany
| | - Irina Trembak-Duff
- Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, 48149 Muenster Germany
| | - Tilmann Unterbarnscheidt
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Konstantin Radyushkin
- Clinical Neuroscience, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Payam Dibaj
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | | | - Susann Boretius
- Biomedizinische NMR Forschungs GmbH, Max Planck Institute of Biophysical Chemistry, 37077 Göttingen, Germany
| | - Magdalena M Brzózka
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Heinz Steffens
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Sebastian Berning
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Zenghui Teng
- Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, 48149 Muenster Germany
| | - Maike N Gummert
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Martesa Tantra
- Clinical Neuroscience, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Peter C Guest
- Institute of Biotechnology, University of Cambridge, Cambridge CB2 1QT, UK
| | - Katrin I Willig
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR Forschungs GmbH, Max Planck Institute of Biophysical Chemistry, 37077 Göttingen, Germany
| | - Stefan W Hell
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Sabine Bahn
- Institute of Biotechnology, University of Cambridge, Cambridge CB2 1QT, UK
| | - Moritz J Rossner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Hannelore Ehrenreich
- Clinical Neuroscience, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Weiqi Zhang
- Laboratory of Molecular Psychiatry, Department of Psychiatry, University of Münster, 48149 Muenster Germany.
| | - Markus H Schwab
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany.
| |
Collapse
|
19
|
Willig KI, Barrantes FJ. Recent applications of superresolution microscopy in neurobiology. Curr Opin Chem Biol 2014; 20:16-21. [PMID: 24793373 DOI: 10.1016/j.cbpa.2014.03.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/26/2014] [Accepted: 03/26/2014] [Indexed: 01/05/2023]
Abstract
Chemical synapses in brain are structural differentiations where excitatory or inhibitory signals are vectorially transmitted between two neurons. Excitatory synapses occur mostly on dendritic spines, submicron sized protrusions of the neuronal dendritic arborizations. Axons establish contacts with these tiny specializations purported to be the smallest functional processing units in the central nervous system. The minute size of synapses and their macromolecular constituents creates an inherent difficulty for imaging but makes them an ideal object for superresolution microscopy. Here we discuss some representative examples of nanoscopy studies, ranging from quantification of receptors and scaffolding proteins in postsynaptic densities and their dynamic behavior, to imaging of synaptic vesicle proteins and dendritic spines in living neurons or even live animals.
Collapse
Affiliation(s)
- Katrin I Willig
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany; Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37077 Göttingen, Germany.
| | - Francisco J Barrantes
- Laboratory of Molecular Neurobiology, BIOMED, Faculty of Medical Sciences, Catholic University of Argentina, UCA-CONICET, 1107 Buenos Aires, Argentina.
| |
Collapse
|
20
|
Jensen NA, Danzl JG, Willig KI, Lavoie-Cardinal F, Brakemann T, Hell SW, Jakobs S. Coordinate-targeted and coordinate-stochastic super-resolution microscopy with the reversibly switchable fluorescent protein Dreiklang. Chemphyschem 2014; 15:756-62. [PMID: 24497300 DOI: 10.1002/cphc.201301034] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Indexed: 11/06/2022]
Abstract
Diffraction-unlimited far-field super-resolution fluorescence (nanoscopy) methods typically rely on transiently transferring fluorophores between two states, whereby this transfer is usually laid out as a switch. However, depending on whether this is induced in a spatially controlled manner using a pattern of light (coordinate-targeted) or stochastically on a single-molecule basis, specific requirements on the fluorophores are imposed. Therefore, the fluorophores are usually utilized just for one class of methods only. In this study we demonstrate that the reversibly switchable fluorescent protein Dreiklang enables live-cell recordings in both spatially controlled and stochastic modes. We show that the Dreiklang chromophore entails three different light-induced switching mechanisms, namely a reversible photochemical one, off-switching by stimulated emission, and a reversible transfer to a long-lived dark state from the S1 state, all of which can be utilized to overcome the diffraction barrier. We also find that for the single-molecule-based stochastic GSDIM approach (ground-state depletion followed by individual molecule return), Dreiklang provides a larger number of on-off localization events as compared to its progenitor Citrine. Altogether, Dreiklang is a versatile probe for essentially all popular forms of live-cell fluorescence nanoscopy.
Collapse
Affiliation(s)
- Nickels A Jensen
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37070 Göttingen (Germany)
| | | | | | | | | | | | | |
Collapse
|
21
|
Eggeling C, Willig KI, Barrantes FJ. STED microscopy of living cells--new frontiers in membrane and neurobiology. J Neurochem 2013; 126:203-12. [PMID: 23506404 DOI: 10.1111/jnc.12243] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 02/18/2013] [Accepted: 03/13/2013] [Indexed: 11/30/2022]
Abstract
Recent developments in fluorescence far-field microscopy such as STED microscopy have accomplished observation of the living cell with a spatial resolution far below the diffraction limit. Here, we briefly review the current approaches to super-resolution optical microscopy and present the implementation of STED microscopy for novel insights into live cell mechanisms, with a focus on neurobiology and plasma membrane dynamics.
Collapse
Affiliation(s)
- Christian Eggeling
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
| | | | | |
Collapse
|
22
|
Nizamov S, Willig KI, Sednev MV, Belov VN, Hell SW. Phosphorylated 3-heteroarylcoumarins and their use in fluorescence microscopy and nanoscopy. Chemistry 2012; 18:16339-48. [PMID: 23111986 DOI: 10.1002/chem.201202382] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 09/13/2012] [Indexed: 11/06/2022]
Abstract
Photostable and bright fluorescent dyes with large Stokes shifts are widely used as markers in far-field optical microscopy, but the variety of useful dyes is limited. The present study introduces new 3-heteroaryl coumarins decorated with a primary phosphate group (OP(O)(OH)(2)) attached to C-4 in 2,2,4-trimethyl-1,2-dihydroquinoline fragment fused with the coumarin fluorophore. The general synthetic route is based on the Suzuki reaction of 3-bromocoumarines with hetarylboronic acids followed by oxidation of the methyl group at the C=C bond with SeO(2) (to an aldehyde), reduction with NaBH(4) (to an alcohol), and conversion into a primary phosphate. The 4 position in the coumarin system may be unsubstituted or bear a methyl group. Phosphorylated coumarins were found to have high fluorescence quantum yields in the free state and after conjugation with proteins (in aqueous buffers). In super-resolution light microscopy with stimulated emission depletion (STED), the new coumarin dyes provide an optical resolution of 40-60 nm with a low background signal. Due to their large Stokes shifts and high photostability, phosphorylated coumarins enable to combine multilabel imaging (using one detector and several excitation sources) with diffraction unlimited optical resolution.
Collapse
Affiliation(s)
- Shamil Nizamov
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | | | | | | | | |
Collapse
|
23
|
Abstract
Lens-based fluorescence microscopy, which has long been limited in resolution to about 200 nanometers by diffraction, is rapidly evolving into a nanoscale imaging technique. Here, we show that the superresolution fluorescence microscopy called RESOLFT enables comparatively fast and continuous imaging of sensitive, nanosized features in living brain tissue. Using low-intensity illumination to switch photochromic fluorescent proteins reversibly between a fluorescent and a nonfluorescent state, we increased the resolution more than 3-fold over that of confocal microscopy in all dimensions. Dendritic spines located 10-50 μm deep inside living organotypic hippocampal brain slices were recorded for hours without signs of degradation. Using a fast-switching protein increased the imaging speed 50-fold over reported RESOLFT schemes, which in turn enabled the recording of spontaneous and stimulated changes of dendritic actin filaments and spine morphology occurring on time scales from seconds to hours.
Collapse
Affiliation(s)
- Ilaria Testa
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | | | | | | | | | | |
Collapse
|
24
|
Willig KI, Nägerl UV. Stimulated emission depletion (STED) imaging of dendritic spines in living hippocampal slices. Cold Spring Harb Protoc 2012; 2012:2012/5/pdb.prot069260. [PMID: 22550296 DOI: 10.1101/pdb.prot069260] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The confluence of innovations in transgenic labeling and light microscopy techniques in recent years has greatly advanced our understanding of dynamic cell biological events underlying neuronal function and plasticity. Increasingly, it has become possible to perform fundamental experiments inside the relevant subcellular compartments of a neuron embedded in three-dimensional living tissues. Overcoming the limiting role of diffraction in far-field light microscopy, nanoscopy is advancing our ability to see and manipulate cellular events well below the diffraction barrier of ∼200 nm. The first concrete and implemented concept of nanoscopy was STED (stimulated emission depletion) microscopy. This article gives an example of the power that STED microscopy holds for neuroscience research. It provides a method for live-cell time-lapse imaging of the dynamic morphology of dendritic spines of pyramidal neurons. Imaging is performed in an organotypic hippocampal slice culture system, with yellow fluorescent protein (YFP) used as a volume marker for the synaptic structures. In addition, the article describes the basic elements needed to assemble a custom-built STED microscope capable of live cell imaging and how to use it for physiology experiments.
Collapse
|
25
|
Urban NT, Willig KI, Hell SW, Nägerl UV. STED nanoscopy of actin dynamics in synapses deep inside living brain slices. Biophys J 2011; 101:1277-84. [PMID: 21889466 DOI: 10.1016/j.bpj.2011.07.027] [Citation(s) in RCA: 234] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 06/15/2011] [Accepted: 07/19/2011] [Indexed: 11/19/2022] Open
Abstract
It is difficult to investigate the mechanisms that mediate long-term changes in synapse function because synapses are small and deeply embedded inside brain tissue. Although recent fluorescence nanoscopy techniques afford improved resolution, they have so far been restricted to dissociated cells or tissue surfaces. However, to study synapses under realistic conditions, one must image several cell layers deep inside more-intact, three-dimensional preparations that exhibit strong light scattering, such as brain slices or brains in vivo. Using aberration-reducing optics, we demonstrate that it is possible to achieve stimulated emission depletion superresolution imaging deep inside scattering biological tissue. To illustrate the power of this novel (to our knowledge) approach, we resolved distinct distributions of actin inside dendrites and spines with a resolution of 60-80 nm in living organotypic brain slices at depths up to 120 μm. In addition, time-lapse stimulated emission depletion imaging revealed changes in actin-based structures inside spines and spine necks, and showed that these dynamics can be modulated by neuronal activity. Our approach greatly facilitates investigations of actin dynamics at the nanoscale within functionally intact brain tissue.
Collapse
Affiliation(s)
- Nicolai T Urban
- Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | | | | | | |
Collapse
|
26
|
Tønnesen J, Nadrigny F, Willig KI, Wedlich-Söldner R, Nägerl UV. Two-color STED microscopy of living synapses using a single laser-beam pair. Biophys J 2011; 101:2545-52. [PMID: 22098754 DOI: 10.1016/j.bpj.2011.10.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 10/07/2011] [Accepted: 10/12/2011] [Indexed: 10/15/2022] Open
Abstract
The advent of superresolution microscopy has opened up new research opportunities into dynamic processes at the nanoscale inside living biological specimens. This is particularly true for synapses, which are very small, highly dynamic, and embedded in brain tissue. Stimulated emission depletion (STED) microscopy, a recently developed laser-scanning technique, has been shown to be well suited for imaging living synapses in brain slices using yellow fluorescent protein as a single label. However, it would be highly desirable to be able to image presynaptic boutons and postsynaptic spines, which together form synapses, using two different fluorophores. As STED microscopy uses separate laser beams for fluorescence excitation and quenching, incorporation of multicolor imaging for STED is more difficult than for conventional light microscopy. Although two-color schemes exist for STED microscopy, these approaches have several drawbacks due to their complexity, cost, and incompatibility with common labeling strategies and fluorophores. Therefore, we set out to develop a straightforward method for two-color STED microscopy that permits the use of popular green-yellow fluorescent labels such as green fluorescent protein, yellow fluorescent protein, Alexa Fluor 488, and calcein green. Our new (to our knowledge) method is based on a single-excitation/STED laser-beam pair to simultaneously excite and quench pairs of these fluorophores, whose signals can be separated by spectral detection and linear unmixing. We illustrate the potential of this approach by two-color superresolution time-lapse imaging of axonal boutons and dendritic spines in living organotypic brain slices.
Collapse
Affiliation(s)
- Jan Tønnesen
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France
| | | | | | | | | |
Collapse
|
27
|
van den Bogaart G, Meyenberg K, Risselada HJ, Amin H, Willig KI, Hubrich BE, Dier M, Hell SW, Grubmüller H, Diederichsen U, Jahn R. Membrane protein sequestering by ionic protein-lipid interactions. Nature 2011; 479:552-5. [PMID: 22020284 PMCID: PMC3409895 DOI: 10.1038/nature10545] [Citation(s) in RCA: 446] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 09/07/2011] [Indexed: 01/01/2023]
Abstract
Neuronal exocytosis is catalyzed by the SNARE protein syntaxin-1A1. Syntaxin-1A is clustered in the plasma membrane at sites where synaptic vesicles undergo exocytosis2,3. However, how syntaxin-1A is sequestered is unknown. Here, we show that syntaxin clustering is mediated by electrostatic interactions with the strongly anionic lipid phosphatidylinositol-4,5-bisphosphate (PIP2). We found with super-resolution STED microscopy on the plasma membrane of PC12 cells that PIP2 is the dominant inner-leaflet lipid in ~73 nm-sized microdomains. This high accumulation of PIP2 was required for syntaxin-1A sequestering, as destruction of PIP2 by the phosphatase synaptojanin-1 reduced syntaxin-1A clustering. Furthermore, co-reconstitution of PIP2 and the C-terminal part of syntaxin-1A in artificial giant unilamellar vesicles resulted in segregation of PIP2 and syntaxin-1A into distinct domains even when cholesterol was absent. Our results demonstrate that electrostatic protein-lipid interactions can result in the formation of microdomains independent of cholesterol or lipid phases.
Collapse
Affiliation(s)
- Geert van den Bogaart
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Abstract
We demonstrate live-cell STED microscopy of two protein species using photochromic green fluorescent proteins as markers. The reversible photoswitching of two markers is implemented so that they can be discerned with a single excitation and STED wavelength and a single detection channel. Dual-label STED microscopy is shown in living mammalian cells.
Collapse
Affiliation(s)
- Katrin I Willig
- Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
| | | | | | | | | |
Collapse
|
29
|
Lalkens B, Testa I, Willig KI, Hell SW. MRT letter: Nanoscopy of protein colocalization in living cells by STED and GSDIM. Microsc Res Tech 2011; 75:1-6. [PMID: 21678524 DOI: 10.1002/jemt.21026] [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] [Received: 03/30/2011] [Accepted: 03/30/2011] [Indexed: 11/05/2022]
Abstract
We report the use of superresolution fluorescence microscopy for studying the nanoscale distribution of protein colocalization in living mammalian cells. Nanoscale imaging is attained both by a targeted and a stochastic fluorescence on-off switching superresolution method, namely by stimulated emission depletion (STED) and ground state depletion microscopy followed by individual molecular return (GSDIM), respectively. Analysis of protein colocalization is performed by bimolecular fluorescence complementation (BiFC). Specifically, a nonfluorescent fragment of the yellow fluorescent protein Citrine is fused to tubulin while a counterpart nonfluorescent fragment is fused to the microtubulin-associated protein MAP2 such that fluorescence is reconstituted on contact of the fragment-carrying proteins. Images with resolution down to 65 nm prove a powerful new way for studying protein colocalization in living cells at the nanoscale.
Collapse
Affiliation(s)
- Birka Lalkens
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
| | | | | | | |
Collapse
|
30
|
Watanabe S, Punge A, Hollopeter G, Willig KI, Hobson RJ, Davis MW, Hell SW, Jorgensen EM. Protein localization in electron micrographs using fluorescence nanoscopy. Nat Methods 2010; 8:80-4. [PMID: 21102453 PMCID: PMC3059187 DOI: 10.1038/nmeth.1537] [Citation(s) in RCA: 307] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2010] [Accepted: 10/20/2010] [Indexed: 11/09/2022]
Abstract
A complete portrait of a cell requires a detailed description of its molecular topography: proteins must be linked to particular organelles. Immunocytochemical electron microscopy can reveal locations of proteins with nanometer resolution but is limited by the quality of fixation, the paucity of antibodies and the inaccessibility of antigens. Here we describe correlative fluorescence electron microscopy for the nanoscopic localization of proteins in electron micrographs. We tagged proteins with the fluorescent proteins Citrine or tdEos and expressed them in Caenorhabditis elegans, fixed the worms and embedded them in plastic. We imaged the tagged proteins from ultrathin sections using stimulated emission depletion (STED) microscopy or photoactivated localization microscopy (PALM). Fluorescence correlated with organelles imaged in electron micrographs from the same sections. We used these methods to localize histones, a mitochondrial protein and a presynaptic dense projection protein in electron micrographs.
Collapse
Affiliation(s)
- Shigeki Watanabe
- Department of Biology and Howard Hughes Medical Institute, University of Utah, Salt Lake City, Utah, USA
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Hein B, Willig KI, Wurm CA, Westphal V, Jakobs S, Hell SW. Stimulated emission depletion nanoscopy of living cells using SNAP-tag fusion proteins. Biophys J 2010; 98:158-63. [PMID: 20074516 DOI: 10.1016/j.bpj.2009.09.053] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 09/20/2009] [Accepted: 09/21/2009] [Indexed: 11/30/2022] Open
Abstract
We show far-field fluorescence nanoscopy of different structural elements labeled with an organic dye within living mammalian cells. The diffraction barrier limiting far-field light microscopy is outperformed by using stimulated emission depletion. We used the tagging protein hAGT (SNAP-tag), which covalently binds benzylguanine-substituted organic dyes, for labeling. Tetramethylrhodamine was used to image the cytoskeleton (vimentin and microtubule-associated protein 2) as well as structures located at the cell membrane (caveolin and connexin-43) with a resolution down to 40 nm. Comparison with structures labeled with the yellow fluorescent protein Citrine validates this labeling approach. Nanoscopic movies showing the movement of connexin-43 clusters across the cell membrane evidence the capability of this technique to observe structural changes on the nanoscale over time. Pulsed or continuous-wave lasers for excitation and stimulated emission depletion yield images of similar resolution in living cells. Hence fusion proteins that bind modified organic dyes expand widely the application range of far-field fluorescence nanoscopy of living cells.
Collapse
Affiliation(s)
- Birka Hein
- Max Planck Institute for Biophysical Chemistry, Department of NanoBiophotonics, Göttingen, Germany
| | | | | | | | | | | |
Collapse
|
32
|
Han KY, Willig KI, Rittweger E, Jelezko F, Eggeling C, Hell SW. Three-dimensional stimulated emission depletion microscopy of nitrogen-vacancy centers in diamond using continuous-wave light. Nano Lett 2009; 9:3323-9. [PMID: 19634862 DOI: 10.1021/nl901597v] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Charged nitrogen-vacancy (NV) color centers in diamond are excellent luminescence sources for far-field fluorescence nanoscopy by stimulated emission depletion (STED). Here we show that these photostable color centers can be visualized by STED using simple continuous-wave or high repetition pulsed lasers (76 MHz) at wavelengths >700 nm for STED. Furthermore, we show that NV centers can be imaged in three dimensions (3D) inside the diamond crystal and present single-photon signatures of single color centers recorded in high density samples, demonstrating a new recording scheme for STED and related far-field nanoscopy approaches. Finally, we exemplify the potential of using nanodiamonds containing NV centers as luminescence tags in STED microscopy. Our results offer new experimental avenues in nanooptics, nanotechnology, and the life sciences.
Collapse
Affiliation(s)
- Kyu Young Han
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | | | | | | | | | | |
Collapse
|
33
|
Willig KI, Hein B, Nägerl UV, Hell SW. STED Nanoscopy in Living Cells using Live Cell Compatible Markers. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
34
|
Abstract
We report stimulated emission depletion (STED) fluorescence microscopy with continuous wave (CW) laser beams. Lateral fluorescence confinement from the scanning focal spot delivered a resolution of 29-60 nm in the focal plane, corresponding to a 5-8-fold improvement over the diffraction barrier. Axial spot confinement increased the axial resolution by 3.5-fold. We observed three-dimensional (3D) subdiffraction resolution in 3D image stacks. Viable for fluorophores with low triplet yield, the use of CW light sources greatly simplifies the implementation of this concept of far-field fluorescence nanoscopy.
Collapse
Affiliation(s)
- Katrin I Willig
- Max Planck Institute for Biophysical Chemistry, Department of NanoBiophotonics, Am Fassberg 11, 37077 Göttingen, Germany
| | | | | | | |
Collapse
|
35
|
Sieber JJ, Willig KI, Kutzner C, Gerding-Reimers C, Harke B, Donnert G, Rammner B, Eggeling C, Hell SW, Grubmüller H, Lang T. Anatomy and Dynamics of a Supramolecular Membrane Protein Cluster. Science 2007; 317:1072-6. [PMID: 17717182 DOI: 10.1126/science.1141727] [Citation(s) in RCA: 317] [Impact Index Per Article: 18.6] [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: 11/02/2022]
Abstract
Most plasmalemmal proteins organize in submicrometer-sized clusters whose architecture and dynamics are still enigmatic. With syntaxin 1 as an example, we applied a combination of far-field optical nanoscopy, biochemistry, fluorescence recovery after photobleaching (FRAP) analysis, and simulations to show that clustering can be explained by self-organization based on simple physical principles. On average, the syntaxin clusters exhibit a diameter of 50 to 60 nanometers and contain 75 densely crowded syntaxins that dynamically exchange with freely diffusing molecules. Self-association depends on weak homophilic protein-protein interactions. Simulations suggest that clustering immobilizes and conformationally constrains the molecules. Moreover, a balance between self-association and crowding-induced steric repulsions is sufficient to explain both the size and dynamics of syntaxin clusters and likely of many oligomerizing membrane proteins that form supramolecular structures.
Collapse
Affiliation(s)
- Jochen J Sieber
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Kellner RR, Baier CJ, Willig KI, Hell SW, Barrantes FJ. Nanoscale organization of nicotinic acetylcholine receptors revealed by stimulated emission depletion microscopy. Neuroscience 2006; 144:135-43. [PMID: 17049171 DOI: 10.1016/j.neuroscience.2006.08.071] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2006] [Revised: 08/22/2006] [Accepted: 08/29/2006] [Indexed: 11/22/2022]
Abstract
Acetylcholine receptor (AChR) supramolecular aggregates that have hitherto only been accessible to examination by electron microscopy were imaged with stimulated emission depletion (STED) fluorescence microscopy, providing resolution beyond limits of diffraction of classical wide-field or confocal microscopes. We examined a Chinese hamster ovary cell liner CHO-K1/A5, that stably expresses adult murine AChR. Whereas confocal microscopy displays AChR clusters as diffraction-limited dots of approximately 200 nm diameter, STED microscopy yields nanoclusters with a peak size distribution of approximately 55 nm. Utilizing this resolution, we show that cholesterol depletion by acute (30 min, 37 degrees C) exposure to methyl-beta-cyclodextrin alters the short and long range organization of AChR nanoclusters on the cell surface. In the short range, AChRs form larger nanoclusters, possibly related to the alteration of cholesterol-dependent protein-protein associations. Ripley's K-test on STED images reveals changes in nanocluster distribution on larger scales (0.5-3.5 microm), which possibly are related to the abolition of cytoskeletal physical barriers preventing the lateral diffusion of AChR nanoclusters.
Collapse
Affiliation(s)
- R R Kellner
- Max Planck Institute for Biophysical Chemistry, Department of NanoBiophotonics, 37077 Göttingen, Germany
| | | | | | | | | |
Collapse
|
37
|
Fitzner D, Schneider A, Kippert A, Möbius W, Willig KI, Hell SW, Bunt G, Gaus K, Simons M. Myelin basic protein-dependent plasma membrane reorganization in the formation of myelin. EMBO J 2006; 25:5037-48. [PMID: 17036049 PMCID: PMC1630406 DOI: 10.1038/sj.emboj.7601376] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Accepted: 09/11/2006] [Indexed: 11/09/2022] Open
Abstract
During vertebrate development, oligodendrocytes wrap their plasma membrane around axons to produce myelin, a specialized membrane highly enriched in galactosylceramide (GalC) and cholesterol. Here, we studied the formation of myelin membrane sheets in a neuron-glia co-culture system. We applied different microscopy techniques to visualize lipid packing and dynamics in the oligodendroglial plasma membrane. We used the fluorescent dye Laurdan to examine the lipid order with two-photon microscopy and observed that neurons induce a dramatic lipid condensation of the oligodendroglial membrane. On a nanoscale resolution, using stimulated emission depletion and fluorescence resonance energy transfer microscopy, we demonstrated a neuronal-dependent clustering of GalC in oligodendrocytes. Most importantly these changes in lipid organization of the oligodendroglial plasma membrane were not observed in shiverer mice that do not express the myelin basic protein. Our data demonstrate that neurons induce the condensation of the myelin-forming bilayer in oligodendrocytes and that MBP is involved in this process of plasma membrane rearrangement. We propose that this mechanism is essential for myelin to perform its insulating function during nerve conduction.
Collapse
Affiliation(s)
- Dirk Fitzner
- Centre for Biochemistry and Molecular Cell Biology, University of Göttingen, Göttingen, Germany
- Max-Planck-Institute for Experimental Medicine, Göttingen, Germany
| | - Anja Schneider
- Centre for Biochemistry and Molecular Cell Biology, University of Göttingen, Göttingen, Germany
- Max-Planck-Institute for Experimental Medicine, Göttingen, Germany
| | - Angelika Kippert
- Centre for Biochemistry and Molecular Cell Biology, University of Göttingen, Göttingen, Germany
- Max-Planck-Institute for Experimental Medicine, Göttingen, Germany
| | - Wiebke Möbius
- Max-Planck-Institute for Experimental Medicine, Göttingen, Germany
| | - Katrin I Willig
- Department of NanoBiophotonics, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Stefan W Hell
- Department of NanoBiophotonics, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Gertrude Bunt
- Max-Planck-Institute for Experimental Medicine, Göttingen, Germany
| | - Katharina Gaus
- Centre for Vascular Research at the School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Mikael Simons
- Centre for Biochemistry and Molecular Cell Biology, University of Göttingen, Göttingen, Germany
- Max-Planck-Institute for Experimental Medicine, Göttingen, Germany
- Centre for Biochemistry and Molecular Cell Biology, Max-Planck Institute for Experimental Medicine, University of Göttingen, Hermann Rein Str. 3, 37073 Göttingen, Germany. Tel.: +49 551 3899533; Fax: +49 551 3899201; E-mail:
| |
Collapse
|
38
|
Willig KI, Kellner RR, Medda R, Hein B, Jakobs S, Hell SW. Nanoscale resolution in GFP-based microscopy. Nat Methods 2006; 3:721-3. [PMID: 16896340 DOI: 10.1038/nmeth922] [Citation(s) in RCA: 291] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2006] [Accepted: 07/17/2006] [Indexed: 11/09/2022]
Abstract
We report attainment of subdiffraction resolution using stimulated emission depletion (STED) microscopy with GFP-labeled samples. The approximately 70 nm lateral resolution attained in this study is demonstrated by imaging GFP-labeled viruses and the endoplasmic reticulum (ER) of a mammalian cell. Our results mark the advent of nanoscale biological microscopy with genetically encoded markers.
Collapse
Affiliation(s)
- Katrin I Willig
- Max Planck Institute for Biophysical Chemistry, Department of NanoBiophotonics, Am Fassberg 11, 37077 Göttingen, Germany
| | | | | | | | | | | |
Collapse
|
39
|
Kittel RJ, Wichmann C, Rasse TM, Fouquet W, Schmidt M, Schmid A, Wagh DA, Pawlu C, Kellner RR, Willig KI, Hell SW, Buchner E, Heckmann M, Sigrist SJ. Bruchpilot promotes active zone assembly, Ca2+ channel clustering, and vesicle release. Science 2006; 312:1051-4. [PMID: 16614170 DOI: 10.1126/science.1126308] [Citation(s) in RCA: 578] [Impact Index Per Article: 32.1] [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: 11/02/2022]
Abstract
The molecular organization of presynaptic active zones during calcium influx-triggered neurotransmitter release is the focus of intense investigation. The Drosophila coiled-coil domain protein Bruchpilot (BRP) was observed in donut-shaped structures centered at active zones of neuromuscular synapses by using subdiffraction resolution STED (stimulated emission depletion) fluorescence microscopy. At brp mutant active zones, electron-dense projections (T-bars) were entirely lost, Ca2+ channels were reduced in density, evoked vesicle release was depressed, and short-term plasticity was altered. BRP-like proteins seem to establish proximity between Ca2+ channels and vesicles to allow efficient transmitter release and patterned synaptic plasticity.
Collapse
Affiliation(s)
- Robert J Kittel
- European Neuroscience Institute Göttingen, Grisebachstrasse 5, 37077 Göttingen, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Willig KI, Rizzoli SO, Westphal V, Jahn R, Hell SW. STED microscopy reveals that synaptotagmin remains clustered after synaptic vesicle exocytosis. Nature 2006; 440:935-9. [PMID: 16612384 DOI: 10.1038/nature04592] [Citation(s) in RCA: 678] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Accepted: 01/20/2006] [Indexed: 11/08/2022]
Abstract
Synaptic transmission is mediated by neurotransmitters that are stored in synaptic vesicles and released by exocytosis upon activation. The vesicle membrane is then retrieved by endocytosis, and synaptic vesicles are regenerated and re-filled with neurotransmitter. Although many aspects of vesicle recycling are understood, the fate of the vesicles after fusion is still unclear. Do their components diffuse on the plasma membrane, or do they remain together? This question has been difficult to answer because synaptic vesicles are too small (approximately 40 nm in diameter) and too densely packed to be resolved by available fluorescence microscopes. Here we use stimulated emission depletion (STED) to reduce the focal spot area by about an order of magnitude below the diffraction limit, thereby resolving individual vesicles in the synapse. We show that synaptotagmin I, a protein resident in the vesicle membrane, remains clustered in isolated patches on the presynaptic membrane regardless of whether the nerve terminals are mildly active or intensely stimulated. This suggests that at least some vesicle constituents remain together during recycling. Our study also demonstrates that questions involving cellular structures with dimensions of a few tens of nanometres can be resolved with conventional far-field optics and visible light.
Collapse
Affiliation(s)
- Katrin I Willig
- Departments of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | | | | | | | | |
Collapse
|
41
|
Abstract
In the plasma membrane, syntaxin 1 and syntaxin 4 clusters define sites at which secretory granules and caveolae fuse, respectively. It is widely believed that lipid phases are mandatory for cluster formation, as cluster integrity depends on cholesterol. Here we report that the native lipid environment is not sufficient for correct syntaxin 1 clustering and that additional cytoplasmic protein-protein interactions, primarily involving the SNARE motif, are required. Apparently no specific cofactors are needed because i), clusters form equally well in nonneuronal cells, and ii), as revealed by nanoscale subdiffraction resolution provided by STED microscopy, the number of clusters directly depends on the syntaxin 1 concentration. For syntaxin 4 clustering the N-terminal domain and the linker region are also dispensable. Moreover, clustering is specific because in both cluster types syntaxins mutually exclude one another at endogenous levels. We suggest that the SNARE motifs of syntaxin 1 and 4 mediate specific syntaxin clustering by homooligomerization, thereby spatially separating sites for different biological activities. Thus, syntaxin clustering represents a mechanism of membrane patterning that is based on protein-protein interactions.
Collapse
Affiliation(s)
- Jochen J Sieber
- Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | | | | | | | | |
Collapse
|