1
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Ray A, Loghinov I, Ravindranath V, Barth AL. Early hippocampal hyperexcitability and synaptic reorganization in mouse models of amyloidosis. iScience 2024; 27:110629. [PMID: 39262788 PMCID: PMC11388185 DOI: 10.1016/j.isci.2024.110629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/09/2024] [Accepted: 07/29/2024] [Indexed: 09/13/2024] Open
Abstract
The limited success of plaque-reducing therapies in Alzheimer's disease suggests that early treatment might be more effective in delaying or reversing memory impairments. Toward this end, it is important to establish the progression of synaptic and circuit changes before onset of plaques or cognitive deficits. Here, we used quantitative, fluorescence-based methods for synapse detection in CA1 pyramidal neurons to investigate the interaction between abnormal circuit activity, measured by Fos-immunoreactivity, and synapse reorganization in mouse models of amyloidosis. Using a genetically encoded, fluorescently labeled synaptic marker in juvenile mice (prior to sexual maturity), we find both synapse gain and loss depending on dendritic location. This progresses to broad synapse loss in aged mice. Elevated hippocampal activity in both CA3 and CA1 was present at weaning and preceded this reorganization. Thus, Aβ overproduction may initiate abnormal activity and subsequent input-specific synapse plasticity. These findings indicate that sustained amyloidosis drives heterogeneous and progressive circuit-wide abnormalities.
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Affiliation(s)
- Ajit Ray
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Iulia Loghinov
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Vijayalakshmi Ravindranath
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, Karnataka 560012, India
- Centre for Brain Research, Indian Institute of Science, Bengaluru, Karnataka 560012, India
| | - Alison L Barth
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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2
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Kida H, Toyoshima S, Kawakami R, Sakimoto Y, Mitsushima D. Properties of layer V pyramidal neurons in the primary motor cortex that represent acquired motor skills. Neuroscience 2024; 559:54-63. [PMID: 39209105 DOI: 10.1016/j.neuroscience.2024.08.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 08/19/2024] [Accepted: 08/22/2024] [Indexed: 09/04/2024]
Abstract
Layer V neurons in primary motor cortex (M1) are required for motor skill learning. We analyzed training-induced plasticity using a whole-cell slice patch-clamp technique with a rotor rod task, and found that training induces diverse changes in intrinsic properties and synaptic plasticity in M1 layer V neurons. Although the causal relationship between specific cellular changes and motor performance is unclear, by linking individual motor performance to cellular/synaptic functions, we identified several cellular and synaptic parameters that represent acquired motor skills. With respect to cellular properties, motor performance was positively correlated with resting membrane potential and fast afterhyperpolarization, but not with the membrane resistance, capacitance, or threshold. With respect to synaptic function, the performance was positively correlated with AMPA receptor-mediated postsynaptic currents, but not with GABAA receptor-mediated postsynaptic currents. With respect to live imaging analysis in Thy1-YFP mice, we further demonstrated a cross-correlation between motor performance, spine head volume, and self-entropy per spine. In the present study, we identified several changes in M1 layer V pyramidal neurons after motor training that represent acquired motor skills. Furthermore, training increased extracellular acetylcholine levels known to promote synaptic plasticity, which is correlated with individual motor performance. These results suggest that systematic control of specific intracellular parameters and enhancement of synaptic plasticity in M1 layer V neurons may be useful for improving motor skills.
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Affiliation(s)
- H Kida
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Yamaguchi 755-8505, Japan.
| | - S Toyoshima
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Yamaguchi 755-8505, Japan
| | - R Kawakami
- Department of Molecular Medicine for Pathogenesis, Graduate School of Medicine, Ehime University, Ehime 791-0295, Japan
| | - Y Sakimoto
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Yamaguchi 755-8505, Japan
| | - D Mitsushima
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Yamaguchi 755-8505, Japan; The Research Institute for Time Studies, Yamaguchi University, Yamaguchi 753-8511, Japan.
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3
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Timalsina B, Lee S, Kaang BK. Advances in the labelling and selective manipulation of synapses. Nat Rev Neurosci 2024:10.1038/s41583-024-00851-9. [PMID: 39174832 DOI: 10.1038/s41583-024-00851-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2024] [Indexed: 08/24/2024]
Abstract
Synapses are highly specialized neuronal structures that are essential for neurotransmission, and they are dynamically regulated throughout the lifetime. Although accumulating evidence indicates that these structures are crucial for information processing and storage in the brain, their precise roles beyond neurotransmission are yet to be fully appreciated. Genetically encoded fluorescent tools have deepened our understanding of synaptic structure and function, but developing an ideal methodology to selectively visualize, label and manipulate synapses remains challenging. Here, we provide an overview of currently available synapse labelling techniques and describe their extension to enable synapse manipulation. We categorize these approaches on the basis of their conceptual bases and target molecules, compare their advantages and limitations and propose potential modifications to improve their effectiveness. These methods have broad utility, particularly for investigating mechanisms of synaptic function and synaptopathy.
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Affiliation(s)
- Binod Timalsina
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Sangkyu Lee
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea
| | - Bong-Kiun Kaang
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon, South Korea.
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4
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Behrens L, Walter RM, Cai W, Ewers H, van Bommel B, Zemella A. Fast In Vitro Synthesis and Direct Labeling of Nanobodies for Prototyping in Microscopy Applications. ACS OMEGA 2024; 9:35374-35383. [PMID: 39184460 PMCID: PMC11339826 DOI: 10.1021/acsomega.4c01164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 07/26/2024] [Accepted: 07/26/2024] [Indexed: 08/27/2024]
Abstract
Small antigen binders, such as nanobodies, have become widely used in biomedical research and pharmaceutical development. However, the pipeline for the generation of functional conjugated probes and drugs from identified binders remains a major time-consuming bottleneck. Here, we developed a method for fast nanobody production and conjugation based on an in vitro synthesis platform. Our system allows for small batch synthesis of nanobodies with the inclusion of a noncanonical amino acid (NCAA). This NCAA can then be used for direct conjugation of molecules to the synthesized nanobody using click-chemistry, reducing the time from binder-encoding DNA to a conjugated probe tremendously. In this study, we conjugated a fluorescent dye to an anti-Green fluorescent protein (GFP) nanobody and attained a fully functional probe suitable for advanced super-resolution microscopy within a short time frame of 2 days. Our work illustrates that an in vitro synthesis platform in combination with click-chemistry can be successfully employed to produce conjugated small antigen binding probes. The fast production and conjugation, combined with the possibility for parallelization as well as precise analysis by microscopy, forms an excellent platform for nanobody prototyping. The here-illustrated method can be used for quick selection and benchmarking of obtained nanobody sequences/clones, e. g., from a phage-display, for use as conjugated small-molecule carriers. This procedure can accelerate the bioengineering of nanobodies for research and pharmaceutical applications.
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Affiliation(s)
- Lukas Behrens
- Institut
für Chemie und Biochemie, Freie Universität
Berlin, Thielallee 63, 14195 Berlin, Germany
- Branch
Bioanalytics and Bioprocesses, Fraunhofer
Institute for Cell Therapy and Immunology, Am Mühlenberg 13, 14476 Potsdam, Germany
| | - Ruben Magnus Walter
- Branch
Bioanalytics and Bioprocesses, Fraunhofer
Institute for Cell Therapy and Immunology, Am Mühlenberg 13, 14476 Potsdam, Germany
- Institute
of Biotechnology, Technische Universität
Berlin, Straße des
17. Juni 135, 10623 Berlin, Germany
| | - Weining Cai
- Institut
für Chemie und Biochemie, Freie Universität
Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Helge Ewers
- Institut
für Chemie und Biochemie, Freie Universität
Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Bas van Bommel
- Institut
für Chemie und Biochemie, Freie Universität
Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Anne Zemella
- Branch
Bioanalytics and Bioprocesses, Fraunhofer
Institute for Cell Therapy and Immunology, Am Mühlenberg 13, 14476 Potsdam, Germany
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5
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Heuer SE, Bloss EB, Howell GR. Strategies to dissect microglia-synaptic interactions during aging and in Alzheimer's disease. Neuropharmacology 2024; 254:109987. [PMID: 38705570 DOI: 10.1016/j.neuropharm.2024.109987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 04/29/2024] [Accepted: 05/02/2024] [Indexed: 05/07/2024]
Abstract
Age is the largest risk factor for developing Alzheimer's disease (AD), a neurodegenerative disorder that causes a progressive and severe dementia. The underlying cause of cognitive deficits seen in AD is thought to be the disconnection of neural circuits that control memory and executive functions. Insight into the mechanisms by which AD diverges from normal aging will require identifying precisely which cellular events are driven by aging and which are impacted by AD-related pathologies. Since microglia, the brain-resident macrophages, are known to have critical roles in the formation and maintenance of neural circuits through synaptic pruning, they are well-positioned to modulate synaptic connectivity in circuits sensitive to aging or AD. In this review, we provide an overview of the current state of the field and on emerging technologies being employed to elucidate microglia-synaptic interactions in aging and AD. We also discuss the importance of leveraging genetic diversity to study how these interactions are shaped across more realistic contexts. We propose that these approaches will be essential to define specific aging- and disease-relevant trajectories for more personalized therapeutics aimed at reducing the effects of age or AD pathologies on the brain. This article is part of the Special Issue on "Microglia".
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Affiliation(s)
- Sarah E Heuer
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA; Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Erik B Bloss
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA; Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA; Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, 04469, USA.
| | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA; Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA; Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, 04469, USA.
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6
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Falace A, Corbieres L, Palminha C, Guarnieri FC, Schaller F, Buhler E, Tuccari di San Carlo C, Montheil A, Watrin F, Manent JB, Represa A, de Chevigny A, Pallesi-Pocachard E, Cardoso C. FLNA regulates neuronal maturation by modulating RAC1-Cofilin activity in the developing cortex. Neurobiol Dis 2024; 198:106558. [PMID: 38852754 DOI: 10.1016/j.nbd.2024.106558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 06/05/2024] [Accepted: 06/05/2024] [Indexed: 06/11/2024] Open
Abstract
Periventricular nodular heterotopia (PNH), the most common brain malformation diagnosed in adulthood, is characterized by the presence of neuronal nodules along the ventricular walls. PNH is mainly associated with mutations in the FLNA gene - encoding an actin-binding protein - and patients often develop epilepsy. However, the molecular mechanisms underlying the neuronal failure still remain elusive. It has been hypothesized that dysfunctional cortical circuitry, rather than ectopic neurons, may explain the clinical manifestations. To address this issue, we depleted FLNA from cortical pyramidal neurons of a conditional Flnaflox/flox mice by timed in utero electroporation of Cre recombinase. We found that FLNA regulates dendritogenesis and spinogenesis thus promoting an appropriate excitatory/inhibitory inputs balance. We demonstrated that FLNA modulates RAC1 and cofilin activity through its interaction with the Rho-GTPase Activating Protein 24 (ARHGAP24). Collectively, we disclose an uncharacterized role of FLNA and provide strong support for neural circuit dysfunction being a consequence of FLNA mutations.
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Affiliation(s)
- Antonio Falace
- Pediatric Neurology and Muscular Diseases Unit, IRCCS Istituto "Giannina Gaslini", Genova, Italy.
| | - Lea Corbieres
- INMED, INSERM UMR1249, Aix Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Catia Palminha
- INMED, INSERM UMR1249, Aix Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Fabrizia Claudia Guarnieri
- Institute of Neuroscience, National Research Council (CNR), Vedano al Lambro (MB), Italy; IRCSS San Raffaele Scientific Institute, Milan, Italy
| | - Fabienne Schaller
- INMED, INSERM UMR1249, Aix Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Emmanuelle Buhler
- INMED, INSERM UMR1249, Aix Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Clara Tuccari di San Carlo
- Pediatric Neurology Unit and Laboratories, IRCCS Meyer Children's Hospital University of Florence, Firenze, Italy
| | - Aurelie Montheil
- INMED, INSERM UMR1249, Aix Marseille University, Parc Scientifique de Luminy, Marseille, France; INMED, INSERM UMR1249, Aix Marseille University, Molecular and Cellular Biology Platform, Parc Scientifique de Luminy, Marseille, France
| | - Françoise Watrin
- INMED, INSERM UMR1249, Aix Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Jean Bernard Manent
- INMED, INSERM UMR1249, Aix Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Alfonso Represa
- INMED, INSERM UMR1249, Aix Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Antoine de Chevigny
- INMED, INSERM UMR1249, Aix Marseille University, Parc Scientifique de Luminy, Marseille, France
| | - Emilie Pallesi-Pocachard
- INMED, INSERM UMR1249, Aix Marseille University, Parc Scientifique de Luminy, Marseille, France; INMED, INSERM UMR1249, Aix Marseille University, Molecular and Cellular Biology Platform, Parc Scientifique de Luminy, Marseille, France
| | - Carlos Cardoso
- INMED, INSERM UMR1249, Aix Marseille University, Parc Scientifique de Luminy, Marseille, France.
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7
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Froehlich T, Jenner A, Cavarischia-Rega C, Fagbadebo FO, Lurz Y, Frecot DI, Kaiser PD, Nueske S, Scholz AM, Schäffer E, Garcia-Saez AJ, Macek B, Rothbauer U. Nanobodies as novel tools to monitor the mitochondrial fission factor Drp1. Life Sci Alliance 2024; 7:e202402608. [PMID: 38816213 PMCID: PMC11140114 DOI: 10.26508/lsa.202402608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 06/01/2024] Open
Abstract
In cells, mitochondria undergo constant fusion and fission. An essential factor for fission is the mammalian dynamin-related protein 1 (Drp1). Dysregulation of Drp1 is associated with neurodegenerative diseases including Parkinson's, cardiovascular diseases and cancer, making Drp1 a pivotal biomarker for monitoring mitochondrial status and potential pathophysiological conditions. Here, we developed nanobodies (Nbs) as versatile binding molecules for proteomics, advanced microscopy and live cell imaging of Drp1. To specifically enrich endogenous Drp1 with interacting proteins for proteomics, we functionalized high-affinity Nbs into advanced capture matrices. Furthermore, we detected Drp1 by bivalent Nbs combined with site-directed fluorophore labelling in super-resolution STORM microscopy. For real-time imaging of Drp1, we intracellularly expressed fluorescently labelled Nbs, so-called chromobodies (Cbs). To improve the signal-to-noise ratio, we further converted Cbs into a "turnover-accelerated" format. With these imaging probes, we visualized the dynamics of endogenous Drp1 upon compound-induced mitochondrial fission in living cells. Considering the wide range of research applications, the presented Nb toolset will open up new possibilities for advanced functional studies of Drp1 in disease-relevant models.
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Affiliation(s)
- Theresa Froehlich
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Andreas Jenner
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Claudia Cavarischia-Rega
- Quantitative Proteomics, Department of Biology, Institute of Cell Biology, Eberhard Karls University Tübingen, Tübingen, Germany
| | | | - Yannic Lurz
- Center for Plant Molecular Biology (ZMBP), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Desiree I Frecot
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Philipp D Kaiser
- https://ror.org/03a1kwz48 NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Stefan Nueske
- Livestock Center of the Faculty of Veterinary Medicine, Ludwig Maximilians University Munich, Munich, Germany
| | - Armin M Scholz
- Livestock Center of the Faculty of Veterinary Medicine, Ludwig Maximilians University Munich, Munich, Germany
| | - Erik Schäffer
- Center for Plant Molecular Biology (ZMBP), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Ana J Garcia-Saez
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Boris Macek
- Quantitative Proteomics, Department of Biology, Institute of Cell Biology, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Ulrich Rothbauer
- Pharmaceutical Biotechnology, Eberhard Karls University Tübingen, Tübingen, Germany
- https://ror.org/03a1kwz48 Cluster of Excellence iFIT (EXC2180) "Image-Guided and Functionally Instructed Tumor Therapies," University of Tübingen, Tübingen, Germany
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8
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Fernandes EFA, Palner M, Raval NR, Jeppesen TE, Danková D, Bærentzen SL, Werner C, Eilts J, Maric HM, Doose S, Aripaka SS, Kaalund SS, Aznar S, Kjaer A, Schlosser A, Haugaard-Kedström LM, Knudsen GM, Herth MM, Stro Mgaard K. Development of Peptide-Based Probes for Molecular Imaging of the Postsynaptic Density in the Brain. J Med Chem 2024; 67:11975-11988. [PMID: 38981131 DOI: 10.1021/acs.jmedchem.4c00615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
The postsynaptic density (PSD) comprises numerous scaffolding proteins, receptors, and signaling molecules that coordinate synaptic transmission in the brain. Postsynaptic density protein 95 (PSD-95) is a master scaffold protein within the PSD and one of its most abundant proteins and therefore constitutes a very attractive biomarker of PSD function and its pathological changes. Here, we exploit a high-affinity inhibitor of PSD-95, AVLX-144, as a template for developing probes for molecular imaging of the PSD. AVLX-144-based probes were labeled with the radioisotopes fluorine-18 and tritium, as well as a fluorescent tag. Tracer binding showed saturable, displaceable, and uneven distribution in rat brain slices, proving effective in quantitative autoradiography and cell imaging studies. Notably, we observed diminished tracer binding in human post-mortem Parkinson's disease (PD) brain slices, suggesting postsynaptic impairment in PD. We thus offer a suite of translational probes for visualizing and understanding PSD-related pathologies.
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Affiliation(s)
- Eduardo F A Fernandes
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark
| | - Mikael Palner
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, Copenhagen DK-2100, Denmark
| | - Nakul Ravi Raval
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, Copenhagen DK-2100, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3, Copenhagen DK-2200, Denmark
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut 06520, United States
| | - Troels E Jeppesen
- Department of Clinical Physiology and Nuclear Medicine & Cluster for Molecular Imaging, Copenhagen University Hospital - Rigshospitalet & Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, Copenhagen DK-2200, Denmark
| | - Daniela Danková
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark
| | - Simone L Bærentzen
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, Copenhagen DK-2100, Denmark
| | - Christian Werner
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University, Am Hubland, Würzburg D-97074, Germany
| | - Janna Eilts
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University, Am Hubland, Würzburg D-97074, Germany
| | - Hans M Maric
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark
- Rudolf Virchow Center for Integrative and Translational Bioimaging, Julius-Maximilians-University, Josef-Schneider-Str. 2, Würzburg 97080, Germany
| | - Sören Doose
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University, Am Hubland, Würzburg D-97074, Germany
| | - Sanjay Sagar Aripaka
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, Copenhagen DK-2100, Denmark
| | - Sanne Simone Kaalund
- Center for Neuroscience and Stereology, Bispebjerg University Hospital, Nielsine Nielsens Vej 6B, Copenhagen DK-2400, Denmark
| | - Susana Aznar
- Center for Neuroscience and Stereology, Bispebjerg University Hospital, Nielsine Nielsens Vej 6B, Copenhagen DK-2400, Denmark
- Center for Translational Research, Bispebjerg University Hospital, Nielsine Nielsens Vej 4B, Copenhagen DK-2400, Denmark
| | - Andreas Kjaer
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3, Copenhagen DK-2200, Denmark
- Department of Clinical Physiology and Nuclear Medicine & Cluster for Molecular Imaging, Copenhagen University Hospital - Rigshospitalet & Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, Copenhagen DK-2200, Denmark
| | - Andreas Schlosser
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University, Am Hubland, Würzburg D-97074, Germany
| | - Linda M Haugaard-Kedström
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, Copenhagen DK-2100, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3, Copenhagen DK-2200, Denmark
| | - Matthias M Herth
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark
- Neurobiology Research Unit, Rigshospitalet, Blegdamsvej 9, Copenhagen DK-2100, Denmark
- Department of Clinical Physiology and Nuclear Medicine & Cluster for Molecular Imaging, Copenhagen University Hospital - Rigshospitalet & Department of Biomedical Sciences, University of Copenhagen, Blegdamsvej 3, Copenhagen DK-2200, Denmark
| | - Kristian Stro Mgaard
- Center for Biopharmaceuticals, Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark
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9
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Kim J, Bustamante E, Sotonyi P, Maxwell N, Parameswaran P, Kent JK, Wetsel WC, Soderblom EJ, Rácz B, Soderling SH. Presynaptic Rac1 in the hippocampus selectively regulates working memory. eLife 2024; 13:RP97289. [PMID: 39046788 PMCID: PMC11268886 DOI: 10.7554/elife.97289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2024] Open
Abstract
One of the most extensively studied members of the Ras superfamily of small GTPases, Rac1 is an intracellular signal transducer that remodels actin and phosphorylation signaling networks. Previous studies have shown that Rac1-mediated signaling is associated with hippocampal-dependent working memory and longer-term forms of learning and memory and that Rac1 can modulate forms of both pre- and postsynaptic plasticity. How these different cognitive functions and forms of plasticity mediated by Rac1 are linked, however, is unclear. Here, we show that spatial working memory in mice is selectively impaired following the expression of a genetically encoded Rac1 inhibitor at presynaptic terminals, while longer-term cognitive processes are affected by Rac1 inhibition at postsynaptic sites. To investigate the regulatory mechanisms of this presynaptic process, we leveraged new advances in mass spectrometry to identify the proteomic and post-translational landscape of presynaptic Rac1 signaling. We identified serine/threonine kinases and phosphorylated cytoskeletal signaling and synaptic vesicle proteins enriched with active Rac1. The phosphorylated sites in these proteins are at positions likely to have regulatory effects on synaptic vesicles. Consistent with this, we also report changes in the distribution and morphology of synaptic vesicles and in postsynaptic ultrastructure following presynaptic Rac1 inhibition. Overall, this study reveals a previously unrecognized presynaptic role of Rac1 signaling in cognitive processes and provides insights into its potential regulatory mechanisms.
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Affiliation(s)
- Jaebin Kim
- Department of Cell Biology, Duke University School of MedicineDurhamUnited States
| | - Edwin Bustamante
- Department of Cell Biology, Duke University School of MedicineDurhamUnited States
| | - Peter Sotonyi
- Department of Anatomy and Histology, University of Veterinary MedicineBudapestHungary
| | - Nicholas Maxwell
- Department of Cell Biology, Duke University School of MedicineDurhamUnited States
| | - Pooja Parameswaran
- Department of Cell Biology, Duke University School of MedicineDurhamUnited States
| | - Julie K Kent
- Department of Cell Biology, Duke University School of MedicineDurhamUnited States
| | - William C Wetsel
- Department of Cell Biology, Duke University School of MedicineDurhamUnited States
- Department of Psychiatry and Behavioral Sciences, Duke University School of MedicineDurhamUnited States
- Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University School of MedicineDurhamUnited States
- Department of Neurobiology, Duke University School of MedicineDurhamUnited States
| | - Erik J Soderblom
- Department of Cell Biology, Duke University School of MedicineDurhamUnited States
- Proteomics and Metabolomics Shared Resource and Center for Genomic and Computational Biology, Duke University School of MedicineDurhamUnited States
| | - Bence Rácz
- Department of Anatomy and Histology, University of Veterinary MedicineBudapestHungary
| | - Scott H Soderling
- Department of Cell Biology, Duke University School of MedicineDurhamUnited States
- Department of Neurobiology, Duke University School of MedicineDurhamUnited States
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10
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Horton S, Mastrolia V, Jackson RE, Kemlo S, Pereira Machado PM, Carbajal MA, Hindges R, Fleck RA, Aguiar P, Neves G, Burrone J. Excitatory and inhibitory synapses show a tight subcellular correlation that weakens over development. Cell Rep 2024; 43:114361. [PMID: 38900634 DOI: 10.1016/j.celrep.2024.114361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/24/2024] [Accepted: 05/30/2024] [Indexed: 06/22/2024] Open
Abstract
Neurons receive correlated levels of excitation and inhibition, a feature that is important for proper brain function. However, how this relationship between excitatory and inhibitory inputs is established during the dynamic period of circuit wiring remains unexplored. Using multiple techniques, including in utero electroporation, electron microscopy, and electrophysiology, we reveal a tight correlation in the distribution of excitatory and inhibitory synapses along the dendrites of developing CA1 hippocampal neurons. This correlation was present within short dendritic stretches (<20 μm) and, surprisingly, was most pronounced during early development, sharply declining with maturity. The tight matching between excitation and inhibition was unexpected, as inhibitory synapses lacked an active zone when formed and exhibited compromised evoked release. We propose that inhibitory synapses form as a stabilizing scaffold to counterbalance growing excitation levels. This relationship diminishes over time, suggesting a critical role for a subcellular balance in early neuronal function and circuit formation.
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Affiliation(s)
- Sally Horton
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Vincenzo Mastrolia
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Rachel E Jackson
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Sarah Kemlo
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Pedro M Pereira Machado
- Centre for Ultrastructural Imaging (CUI), Kings College London, New Hunts House, Guys Hospital Campus, London SE1 1UL, UK
| | - Maria Alejandra Carbajal
- Centre for Ultrastructural Imaging (CUI), Kings College London, New Hunts House, Guys Hospital Campus, London SE1 1UL, UK
| | - Robert Hindges
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Roland A Fleck
- Centre for Ultrastructural Imaging (CUI), Kings College London, New Hunts House, Guys Hospital Campus, London SE1 1UL, UK
| | - Paulo Aguiar
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Guilherme Neves
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK.
| | - Juan Burrone
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK.
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11
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Onishi T, Hirose K, Sakaba T. Molecular tools to capture active neural circuits. Front Neural Circuits 2024; 18:1449459. [PMID: 39100199 PMCID: PMC11294111 DOI: 10.3389/fncir.2024.1449459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2024] [Accepted: 07/08/2024] [Indexed: 08/06/2024] Open
Abstract
To understand how neurons and neural circuits function during behaviors, it is essential to record neuronal activity in the brain in vivo. Among the various technologies developed for recording neuronal activity, molecular tools that induce gene expression in an activity-dependent manner have attracted particular attention for their ability to clarify the causal relationships between neuronal activity and behavior. In this review, we summarize recently developed activity-dependent gene expression tools and their potential contributions to the study of neural circuits.
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Affiliation(s)
- Taichi Onishi
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo City, Bunkyo, Japan
| | - Kenzo Hirose
- Department of Pharmacology, Graduate School of Medicine, The University of Tokyo, Bunkyo City, Bunkyo, Japan
| | - Takeshi Sakaba
- Graduate School of Brain Science, Doshisha University, Kyotanabe, Kyoto, Japan
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12
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Tullis JE, Bayer KU. Induction of LTP mechanisms in dually innervated dendritic spines. Sci Rep 2024; 14:15855. [PMID: 38982271 PMCID: PMC11233660 DOI: 10.1038/s41598-024-66871-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 07/04/2024] [Indexed: 07/11/2024] Open
Abstract
Dendritic spines are the postsynaptic compartments of excitatory synapses, however, a substantial subset of spines additionally receives inhibitory input. In such dually innervated spines (DiSs), excitatory long-term potentiation (LTP) mechanisms are suppressed, but can be enabled by blocking tonic inhibitory GABAB receptor signaling. Here we show that LTP mechanisms at DiSs are also enabled by two other excitatory LTP stimuli. In hippocampal neurons, these chemical LTP (cLTP) stimuli induced robust movement of the Ca2+/calmodulin-dependent protein kinase II (CaMKII) to DiSs. Such synaptic CaMKII accumulation is an essential LTP mechanism at singly innervated spines (SiSs). Indeed, CaMKII accumulation at DiSs was also accompanied by other readouts for successful LTP induction: spine growth and surface insertion of GluA1. Thus, DiSs are capable of the same LTP mechanisms as SiSs, although induction of these mechanism additionally requires either reduced inhibitory signaling or increased excitatory stimulation. This additional regulation may provide further computational control.
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Affiliation(s)
- Jonathan E Tullis
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - K Ulrich Bayer
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.
- Program in Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.
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13
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Fukata Y, Fukata M, MacGillavry HD, Nair D, Hosy E. Celebrating the Birthday of AMPA Receptor Nanodomains: Illuminating the Nanoscale Organization of Excitatory Synapses with 10 Nanocandles. J Neurosci 2024; 44:e2104232024. [PMID: 38839340 PMCID: PMC11154862 DOI: 10.1523/jneurosci.2104-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 04/02/2024] [Accepted: 04/03/2024] [Indexed: 06/07/2024] Open
Abstract
A decade ago, in 2013, and over the course of 4 summer months, three separate observations were reported that each shed light independently on a new molecular organization that fundamentally reshaped our perception of excitatory synaptic transmission (Fukata et al., 2013; MacGillavry et al., 2013; Nair et al., 2013). This discovery unveiled an intricate arrangement of AMPA-type glutamate receptors and their principal scaffolding protein PSD-95, at synapses. This breakthrough was made possible, thanks to advanced super-resolution imaging techniques. It fundamentally changed our understanding of excitatory synaptic architecture and paved the way for a brand-new area of research. In this Progressions article, the primary investigators of the nanoscale organization of synapses have come together to chronicle the tale of their discovery. We recount the initial inquiry that prompted our research, the preceding studies that inspired our work, the technical obstacles that were encountered, and the breakthroughs that were made in the subsequent decade in the realm of nanoscale synaptic transmission. We review the new discoveries made possible by the democratization of super-resolution imaging techniques in the field of excitatory synaptic physiology and architecture, first by the extension to other glutamate receptors and to presynaptic proteins and then by the notion of trans-synaptic organization. After describing the organizational modifications occurring in various pathologies, we discuss briefly the latest technical developments made possible by super-resolution imaging and emerging concepts in synaptic physiology.
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Affiliation(s)
- Yuko Fukata
- Division of Molecular and Cellular Pharmacology, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Masaki Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Division of Neuropharmacology, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
- Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
| | - Harold D MacGillavry
- Division of Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, The Netherlands
| | - Deepak Nair
- Centre for Neuroscience, Indian Institute of Science, Bangalore 560012, Karnataka, India
| | - Eric Hosy
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, CNRS UMR5297, Bordeaux F-33000, France
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14
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Zhu S, Shen Z, Wu X, Han W, Jia B, Lu W, Zhang M. Demixing is a default process for biological condensates formed via phase separation. Science 2024; 384:920-928. [PMID: 38781377 DOI: 10.1126/science.adj7066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 04/15/2024] [Indexed: 05/25/2024]
Abstract
Excitatory and inhibitory synapses do not overlap even when formed on one submicron-sized dendritic protrusion. How excitatory and inhibitory postsynaptic cytomatrices or densities (e/iPSDs) are segregated is not understood. Broadly, why membraneless organelles are naturally segregated in cellular subcompartments is unclear. Using biochemical reconstitutions in vitro and in cells, we demonstrate that ePSDs and iPSDs spontaneously segregate into distinct condensed molecular assemblies through phase separation. Tagging iPSD scaffold gephyrin with a PSD-95 intrabody (dissociation constant ~4 nM) leads to mistargeting of gephyrin to ePSD condensates. Unexpectedly, formation of iPSD condensates forces the intrabody-tagged gephyrin out of ePSD condensates. Thus, instead of diffusion-governed spontaneous mixing, demixing is a default process for biomolecules in condensates. Phase separation can generate biomolecular compartmentalization specificities that cannot occur in dilute solutions.
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Affiliation(s)
- Shihan Zhu
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
- School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Zeyu Shen
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
- School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xiandeng Wu
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
| | - Wenyan Han
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20824, USA
| | - Bowen Jia
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China
| | - Wei Lu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20824, USA
| | - Mingjie Zhang
- School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, China
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15
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Suppermpool A, Lyons DG, Broom E, Rihel J. Sleep pressure modulates single-neuron synapse number in zebrafish. Nature 2024; 629:639-645. [PMID: 38693264 PMCID: PMC11096099 DOI: 10.1038/s41586-024-07367-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 03/27/2024] [Indexed: 05/03/2024]
Abstract
Sleep is a nearly universal behaviour with unclear functions1. The synaptic homeostasis hypothesis proposes that sleep is required to renormalize the increases in synaptic number and strength that occur during wakefulness2. Some studies examining either large neuronal populations3 or small patches of dendrites4 have found evidence consistent with the synaptic homeostasis hypothesis, but whether sleep merely functions as a permissive state or actively promotes synaptic downregulation at the scale of whole neurons is unclear. Here, by repeatedly imaging all excitatory synapses on single neurons across sleep-wake states of zebrafish larvae, we show that synapses are gained during periods of wake (either spontaneous or forced) and lost during sleep in a neuron-subtype-dependent manner. However, synapse loss is greatest during sleep associated with high sleep pressure after prolonged wakefulness, and lowest in the latter half of an undisrupted night. Conversely, sleep induced pharmacologically during periods of low sleep pressure is insufficient to trigger synapse loss unless adenosine levels are boosted while noradrenergic tone is inhibited. We conclude that sleep-dependent synapse loss is regulated by sleep pressure at the level of the single neuron and that not all sleep periods are equally capable of fulfilling the functions of synaptic homeostasis.
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Affiliation(s)
- Anya Suppermpool
- Department of Cell and Developmental Biology, University College London, London, UK
- UCL Ear Institute, University College London, London, UK
| | - Declan G Lyons
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Elizabeth Broom
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Jason Rihel
- Department of Cell and Developmental Biology, University College London, London, UK.
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16
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Okur Z, Schlauri N, Bitsikas V, Panopoulou M, Ortiz R, Schwaiger M, Karmakar K, Schreiner D, Scheiffele P. Control of neuronal excitation-inhibition balance by BMP-SMAD1 signalling. Nature 2024; 629:402-409. [PMID: 38632412 PMCID: PMC11078759 DOI: 10.1038/s41586-024-07317-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 03/14/2024] [Indexed: 04/19/2024]
Abstract
Throughout life, neuronal networks in the mammalian neocortex maintain a balance of excitation and inhibition, which is essential for neuronal computation1,2. Deviations from a balanced state have been linked to neurodevelopmental disorders, and severe disruptions result in epilepsy3-5. To maintain balance, neuronal microcircuits composed of excitatory and inhibitory neurons sense alterations in neural activity and adjust neuronal connectivity and function. Here we identify a signalling pathway in the adult mouse neocortex that is activated in response to increased neuronal network activity. Overactivation of excitatory neurons is signalled to the network through an increase in the levels of BMP2, a growth factor that is well known for its role as a morphogen in embryonic development. BMP2 acts on parvalbumin-expressing (PV) interneurons through the transcription factor SMAD1, which controls an array of glutamatergic synapse proteins and components of perineuronal nets. PV-interneuron-specific disruption of BMP2-SMAD1 signalling is accompanied by a loss of glutamatergic innervation in PV cells, underdeveloped perineuronal nets and decreased excitability. Ultimately, this impairment of the functional recruitment of PV interneurons disrupts the cortical excitation-inhibition balance, with mice exhibiting spontaneous epileptic seizures. Our findings suggest that developmental morphogen signalling is repurposed to stabilize cortical networks in the adult mammalian brain.
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Affiliation(s)
- Zeynep Okur
- Biozentrum, University of Basel, Basel, Switzerland
| | - Nadia Schlauri
- Biozentrum, University of Basel, Basel, Switzerland
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | | | | | - Raul Ortiz
- Biozentrum, University of Basel, Basel, Switzerland
| | - Michaela Schwaiger
- Swiss Institute of Bioinformatics, Basel, Switzerland
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Kajari Karmakar
- Biozentrum, University of Basel, Basel, Switzerland
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
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17
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Xu N, Cao R, Chen SY, Gou XZ, Wang B, Luo HM, Gao F, Tang AH. Structural and functional reorganization of inhibitory synapses by activity-dependent cleavage of neuroligin-2. Proc Natl Acad Sci U S A 2024; 121:e2314541121. [PMID: 38657049 PMCID: PMC11067042 DOI: 10.1073/pnas.2314541121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 03/21/2024] [Indexed: 04/26/2024] Open
Abstract
Recent evidence has demonstrated that the transsynaptic nanoscale organization of synaptic proteins plays a crucial role in regulating synaptic strength in excitatory synapses. However, the molecular mechanism underlying this transsynaptic nanostructure in inhibitory synapses still remains unclear and its impact on synapse function in physiological or pathological contexts has not been demonstrated. In this study, we utilized an engineered proteolysis technique to investigate the effects of acute cleavage of neuroligin-2 (NL2) on synaptic transmission. Our results show that the rapid cleavage of NL2 led to impaired synaptic transmission by reducing both neurotransmitter release probability and quantum size. These changes were attributed to the dispersion of RIM1/2 and GABAA receptors and a weakened spatial alignment between them at the subsynaptic scale, as observed through superresolution imaging and model simulations. Importantly, we found that endogenous NL2 undergoes rapid MMP9-dependent cleavage during epileptic activities, which further exacerbates the decrease in inhibitory transmission. Overall, our study demonstrates the significant impact of nanoscale structural reorganization on inhibitory transmission and unveils ongoing modulation of mature GABAergic synapses through active cleavage of NL2 in response to hyperactivity.
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Affiliation(s)
- Na Xu
- Department of Neurology, Institute on Aging and Brain Disorders, The First Affiliated Hospital, University of Science and Technology of China, Luyang District, Hefei, Anhui 230001, China
- Anhui Province Key Laboratory of Biomedical Imaging and Intelligent Processing, Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, 5089 Wangjiang West Road, Gaoxin District, Hefei, Anhui 230088, China
- Ministry of Education Key Laboratory for Membrane-less Organelles and Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Shushan District, Hefei, Anhui 230027, China
| | - Ran Cao
- Anhui Province Key Laboratory of Biomedical Imaging and Intelligent Processing, Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, 5089 Wangjiang West Road, Gaoxin District, Hefei, Anhui 230088, China
- Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Baohe District, Hefei, Anhui 230026, China
| | - Si-Yu Chen
- Ministry of Education Key Laboratory for Membrane-less Organelles and Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Shushan District, Hefei, Anhui 230027, China
- Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Baohe District, Hefei, Anhui 230026, China
| | - Xu-Zhuo Gou
- Anhui Province Key Laboratory of Biomedical Imaging and Intelligent Processing, Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, 5089 Wangjiang West Road, Gaoxin District, Hefei, Anhui 230088, China
- Ministry of Education Key Laboratory for Membrane-less Organelles and Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Shushan District, Hefei, Anhui 230027, China
- Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Baohe District, Hefei, Anhui 230026, China
| | - Bin Wang
- Anhui Province Key Laboratory of Biomedical Imaging and Intelligent Processing, Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, 5089 Wangjiang West Road, Gaoxin District, Hefei, Anhui 230088, China
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan 450001, China
| | - Hong-Mei Luo
- Anhui Province Key Laboratory of Biomedical Imaging and Intelligent Processing, Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, 5089 Wangjiang West Road, Gaoxin District, Hefei, Anhui 230088, China
- Ministry of Education Key Laboratory for Membrane-less Organelles and Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Shushan District, Hefei, Anhui 230027, China
| | - Feng Gao
- Department of Neurology, Institute on Aging and Brain Disorders, The First Affiliated Hospital, University of Science and Technology of China, Luyang District, Hefei, Anhui 230001, China
| | - Ai-Hui Tang
- Department of Neurology, Institute on Aging and Brain Disorders, The First Affiliated Hospital, University of Science and Technology of China, Luyang District, Hefei, Anhui 230001, China
- Anhui Province Key Laboratory of Biomedical Imaging and Intelligent Processing, Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, 5089 Wangjiang West Road, Gaoxin District, Hefei, Anhui 230088, China
- Ministry of Education Key Laboratory for Membrane-less Organelles and Cellular Dynamics, Division of Life Sciences and Medicine, University of Science and Technology of China, Shushan District, Hefei, Anhui 230027, China
- Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Baohe District, Hefei, Anhui 230026, China
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18
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Brown CN, Bayer KU. Studying CaMKII: Tools and standards. Cell Rep 2024; 43:113982. [PMID: 38517893 PMCID: PMC11088445 DOI: 10.1016/j.celrep.2024.113982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/19/2024] [Accepted: 03/06/2024] [Indexed: 03/24/2024] Open
Abstract
The Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII) is a ubiquitous mediator of cellular Ca2+ signals with both enzymatic and structural functions. Here, we briefly introduce the complex regulation of CaMKII and then provide a comprehensive overview of the expanding toolbox to study CaMKII. Beyond a variety of distinct mutants, these tools now include optical methods for measurement and manipulation, with the latter including light-induced inhibition, stimulation, and sequestration. Perhaps most importantly, there are now three mechanistically distinct classes of specific CaMKII inhibitors, and their combined use enables the interrogation of CaMKII functions in a manner that is powerful and sophisticated yet also accessible. This review aims to provide guidelines for the interpretation of the results obtained with these tools, with careful consideration of their direct and indirect effects.
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Affiliation(s)
- Carolyn Nicole Brown
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Karl Ulrich Bayer
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
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19
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Braun D, Rosenberg AM, Rabaniam E, Haruvi R, Malamud D, Barbara R, Aiznkot T, Levavi-Sivan B, Kawashima T. High-resolution tracking of unconfined zebrafish behavior reveals stimulatory and anxiolytic effects of psilocybin. Mol Psychiatry 2024; 29:1046-1062. [PMID: 38233467 PMCID: PMC11176078 DOI: 10.1038/s41380-023-02391-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 12/12/2023] [Accepted: 12/19/2023] [Indexed: 01/19/2024]
Abstract
Serotonergic psychedelics are emerging therapeutics for psychiatric disorders, yet their underlying mechanisms of action in the brain remain largely elusive. Here, we developed a wide-field behavioral tracking system for larval zebrafish and investigated the effects of psilocybin, a psychedelic serotonin receptor agonist. Machine learning analyses of precise body kinematics identified latent behavioral states reflecting spontaneous exploration, visually-driven rapid swimming, and irregular swim patterns following stress exposure. Using this method, we found that acute psilocybin treatment has two behavioral effects: [i] facilitation of spontaneous exploration ("stimulatory") and [ii] prevention of irregular swim patterns following stress exposure ("anxiolytic"). These effects differed from the effect of acute SSRI treatment and were rather similar to the effect of ketamine treatment. Neural activity imaging in the dorsal raphe nucleus suggested that psilocybin inhibits serotonergic neurons by activating local GABAergic neurons, consistent with psychedelic-induced suppression of serotonergic neurons in mammals. These findings pave the way for using larval zebrafish to elucidate neural mechanisms underlying the behavioral effects of serotonergic psychedelics.
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Affiliation(s)
- Dotan Braun
- Department of Brain Sciences, Weizmann Institute of Science, 234 Herzl Street, Rehovot, Israel
- The Jerusalem Mental Health Center, Jerusalem, Israel
| | - Ayelet M Rosenberg
- Department of Brain Sciences, Weizmann Institute of Science, 234 Herzl Street, Rehovot, Israel
| | - Elad Rabaniam
- Department of Brain Sciences, Weizmann Institute of Science, 234 Herzl Street, Rehovot, Israel
| | - Ravid Haruvi
- Department of Brain Sciences, Weizmann Institute of Science, 234 Herzl Street, Rehovot, Israel
| | - Dorel Malamud
- Department of Brain Sciences, Weizmann Institute of Science, 234 Herzl Street, Rehovot, Israel
| | - Rani Barbara
- Department of Brain Sciences, Weizmann Institute of Science, 234 Herzl Street, Rehovot, Israel
| | - Tomer Aiznkot
- Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food, and Environment, Hebrew University of Jerusalem, 229 Herzl Street, Rehovot, Israel
| | - Berta Levavi-Sivan
- Department of Animal Sciences, The Robert H. Smith Faculty of Agriculture, Food, and Environment, Hebrew University of Jerusalem, 229 Herzl Street, Rehovot, Israel
| | - Takashi Kawashima
- Department of Brain Sciences, Weizmann Institute of Science, 234 Herzl Street, Rehovot, Israel.
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20
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Kim J, Bustamante E, Sotonyi P, Maxwell ND, Parameswaran P, Kent JK, Wetsel WC, Soderblom EJ, Rácz B, Soderling SH. Presynaptic Rac1 in the hippocampus selectively regulates working memory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.18.585488. [PMID: 38562715 PMCID: PMC10983896 DOI: 10.1101/2024.03.18.585488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
One of the most extensively studied members of the Ras superfamily of small GTPases, Rac1 is an intracellular signal transducer that remodels actin and phosphorylation signaling networks. Previous studies have shown that Rac1-mediated signaling is associated with hippocampal-dependent working memory and longer-term forms of learning and memory and that Rac1 can modulate forms of both pre- and postsynaptic plasticity. How these different cognitive functions and forms of plasticity mediated by Rac1 are linked, however, is unclear. Here, we show that spatial working memory is selectively impaired following the expression of a genetically encoded Rac1-inhibitor at presynaptic terminals, while longer-term cognitive processes are affected by Rac1 inhibition at postsynaptic sites. To investigate the regulatory mechanisms of this presynaptic process, we leveraged new advances in mass spectrometry to identify the proteomic and post-translational landscape of presynaptic Rac1 signaling. We identified serine/threonine kinases and phosphorylated cytoskeletal signaling and synaptic vesicle proteins enriched with active Rac1. The phosphorylated sites in these proteins are at positions likely to have regulatory effects on synaptic vesicles. Consistent with this, we also report changes in the distribution and morphology of synaptic vesicles and in postsynaptic ultrastructure following presynaptic Rac1 inhibition. Overall, this study reveals a previously unrecognized presynaptic role of Rac1 signaling in cognitive processes and provides insights into its potential regulatory mechanisms.
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Affiliation(s)
- Jaebin Kim
- Department of Cell Biology, Duke University Medical School, Durham, North Carolina, USA
| | - Edwin Bustamante
- Department of Cell Biology, Duke University Medical School, Durham, North Carolina, USA
| | - Peter Sotonyi
- Department of Anatomy and Histology, University of Veterinary Medicine, Budapest, Hungary
| | - Nicholas D Maxwell
- Department of Cell Biology, Duke University Medical School, Durham, North Carolina, USA
| | - Pooja Parameswaran
- Department of Cell Biology, Duke University Medical School, Durham, North Carolina, USA
| | - Julie K Kent
- Department of Cell Biology, Duke University Medical School, Durham, North Carolina, USA
| | - William C Wetsel
- Department of Cell Biology, Duke University Medical School, Durham, North Carolina, USA
- Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical School, Durham, North Carolina, USA
- Department of Neurobiology, Duke University Medical School, Durham, North Carolina, USA
| | - Erik J Soderblom
- Department of Cell Biology, Duke University Medical School, Durham, North Carolina, USA
- Mouse Behavioral and Neuroendocrine Analysis Core Facility, Duke University Medical School, Durham, North Carolina, USA
| | - Bence Rácz
- Department of Anatomy and Histology, University of Veterinary Medicine, Budapest, Hungary
| | - Scott H Soderling
- Department of Cell Biology, Duke University Medical School, Durham, North Carolina, USA
- Department of Neurobiology, Duke University Medical School, Durham, North Carolina, USA
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21
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Doszyn O, Dulski T, Zmorzynska J. Diving into the zebrafish brain: exploring neuroscience frontiers with genetic tools, imaging techniques, and behavioral insights. Front Mol Neurosci 2024; 17:1358844. [PMID: 38533456 PMCID: PMC10963419 DOI: 10.3389/fnmol.2024.1358844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/27/2024] [Indexed: 03/28/2024] Open
Abstract
The zebrafish (Danio rerio) is increasingly used in neuroscience research. Zebrafish are relatively easy to maintain, and their high fecundity makes them suitable for high-throughput experiments. Their small, transparent embryos and larvae allow for easy microscopic imaging of the developing brain. Zebrafish also share a high degree of genetic similarity with humans, and are amenable to genetic manipulation techniques, such as gene knockdown, knockout, or knock-in, which allows researchers to study the role of specific genes relevant to human brain development, function, and disease. Zebrafish can also serve as a model for behavioral studies, including locomotion, learning, and social interactions. In this review, we present state-of-the-art methods to study the brain function in zebrafish, including genetic tools for labeling single neurons and neuronal circuits, live imaging of neural activity, synaptic dynamics and protein interactions in the zebrafish brain, optogenetic manipulation, and the use of virtual reality technology for behavioral testing. We highlight the potential of zebrafish for neuroscience research, especially regarding brain development, neuronal circuits, and genetic-based disorders and discuss its certain limitations as a model.
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Affiliation(s)
| | | | - J. Zmorzynska
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology in Warsaw (IIMCB), Warsaw, Poland
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22
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Li J, Miramontes TG, Czopka T, Monk KR. Synaptic input and Ca 2+ activity in zebrafish oligodendrocyte precursor cells contribute to myelin sheath formation. Nat Neurosci 2024; 27:219-231. [PMID: 38216650 DOI: 10.1038/s41593-023-01553-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 12/13/2023] [Indexed: 01/14/2024]
Abstract
In the nervous system, only one type of neuron-glial synapse is known to exist: that between neurons and oligodendrocyte precursor cells (OPCs), yet their composition, assembly, downstream signaling and in vivo functions remain largely unclear. Here, we address these questions using in vivo microscopy in zebrafish spinal cord and identify postsynaptic molecules PSD-95 and gephyrin in OPCs. The puncta containing these molecules in OPCs increase during early development and decrease upon OPC differentiation. These puncta are highly dynamic and frequently assemble at 'hotspots'. Gephyrin hotspots and synapse-associated Ca2+ activity in OPCs predict where a subset of myelin sheaths forms in differentiated oligodendrocytes. Further analyses reveal that spontaneous synaptic release is integral to OPC Ca2+ activity, while evoked synaptic release contributes only in early development. Finally, disruption of the synaptic genes dlg4a/dlg4b, gphnb and nlgn3b impairs OPC differentiation and myelination. Together, we propose that neuron-OPC synapses are dynamically assembled and can predetermine myelination patterns through Ca2+ signaling.
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Affiliation(s)
- Jiaxing Li
- Vollum Institute, Oregon Health & Science University, Portland, OR, USA.
| | | | - Tim Czopka
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Kelly R Monk
- Vollum Institute, Oregon Health & Science University, Portland, OR, USA.
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23
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Niraula S, Yan SS, Subramanian J. Amyloid Pathology Impairs Experience-Dependent Inhibitory Synaptic Plasticity. J Neurosci 2024; 44:e0702232023. [PMID: 38050105 PMCID: PMC10860629 DOI: 10.1523/jneurosci.0702-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 11/09/2023] [Accepted: 11/14/2023] [Indexed: 12/06/2023] Open
Abstract
Alzheimer's disease patients and mouse models exhibit aberrant neuronal activity and altered excitatory-to-inhibitory synaptic ratio. Using multicolor two-photon microscopy, we test how amyloid pathology alters the structural dynamics of excitatory and inhibitory synapses and their adaptation to altered visual experience in vivo in the visual cortex. We show that the baseline dynamics of mature excitatory synapses and their adaptation to visual deprivation are not altered in amyloidosis. Likewise, the baseline dynamics of inhibitory synapses are not affected. In contrast, visual deprivation fails to induce inhibitory synapse loss in amyloidosis, a phenomenon observed in nonpathological conditions. Intriguingly, inhibitory synapse loss associated with visual deprivation in nonpathological mice is accompanied by subtle broadening of spontaneous but not visually evoked calcium transients. However, such broadening does not manifest in the context of amyloidosis. We also show that excitatory and inhibitory synapse loss is locally clustered under the nonpathological state. In contrast, a fraction of synapse loss is not locally clustered in amyloidosis, indicating an impairment in inhibitory synapse adaptation to changes in excitatory synaptic activity.
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Affiliation(s)
- Suraj Niraula
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
| | - Shirley ShiDu Yan
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
- Department of Surgery, Vagelos College of Physicians and Surgeons of Columbia University, New York, New York 10032
| | - Jaichandar Subramanian
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
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24
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Vieira MM, Peng S, Won S, Hong E, Inati SK, Thurm A, Thiam AH, Kim S, Myers SJ, Badger JD, Traynelis SF, Lu W, Roche KW. A Frameshift Variant of GluN2A Identified in an Epilepsy Patient Results in NMDA Receptor Mistargeting. J Neurosci 2024; 44:e0557232023. [PMID: 38050135 PMCID: PMC10860613 DOI: 10.1523/jneurosci.0557-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 08/24/2023] [Accepted: 11/14/2023] [Indexed: 12/06/2023] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) are crucial for neuronal development and synaptic plasticity. Dysfunction of NMDARs is associated with multiple neurodevelopmental disorders, including epilepsy, autism spectrum disorder, and intellectual disability. Understanding the impact of genetic variants of NMDAR subunits can shed light on the mechanisms of disease. Here, we characterized the functional implications of a de novo mutation of the GluN2A subunit (P1199Rfs*32) resulting in the truncation of the C-terminal domain. The variant was identified in a male patient with epileptic encephalopathy, multiple seizure types, severe aphasia, and neurobehavioral changes. Given the known role of the CTD in NMDAR trafficking, we examined changes in receptor localization and abundance at the postsynaptic membrane using a combination of molecular assays in heterologous cells and rat primary neuronal cultures. We observed that the GluN2A P1199Rfs*32-containing receptors traffic efficiently to the postsynaptic membrane but have increased extra-synaptic expression relative to WT GluN2A-containing NMDARs. Using in silico predictions, we hypothesized that the mutant would lose all PDZ interactions, except for the recycling protein Scribble1. Indeed, we observed impaired binding to the scaffolding protein postsynaptic protein-95 (PSD-95); however, we found the mutant interacts with Scribble1, which facilitates the recycling of both the mutant and the WT GluN2A. Finally, we found that neurons expressing GluN2A P1199Rfs*32 have fewer synapses and decreased spine density, indicating compromised synaptic transmission in these neurons. Overall, our data show that GluN2A P1199Rfs*32 is a loss-of-function variant with altered membrane localization in neurons and provide mechanistic insight into disease etiology.
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Affiliation(s)
- M M Vieira
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda 20892, Maryland
| | - S Peng
- Synapse and Neural Circuit Research Section, NINDS, NIH, Bethesda 20892, Maryland
| | - S Won
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda 20892, Maryland
| | - E Hong
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda 20892, Maryland
| | - S K Inati
- Neurophysiology of Epilepsy Unit, NINDS, NIH, Bethesda 20892, Maryland
| | - A Thurm
- National Institute of Mental Health, National Institutes of Health, Bethesda 20892, Maryland
| | - A H Thiam
- Office of the Clinical Director, NINDS, NIH, Bethesda 20892, Maryland
| | - S Kim
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta 30322, Georgia
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta 30322, Georgia
| | - S J Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta 30322, Georgia
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta 30322, Georgia
| | - J D Badger
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda 20892, Maryland
| | - S F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta 30322, Georgia
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta 30322, Georgia
| | - W Lu
- Synapse and Neural Circuit Research Section, NINDS, NIH, Bethesda 20892, Maryland
| | - K W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda 20892, Maryland
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25
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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] [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.
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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
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26
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Rimbault C, Breillat C, Compans B, Toulmé E, Vicente FN, Fernandez-Monreal M, Mascalchi P, Genuer C, Puente-Muñoz V, Gauthereau I, Hosy E, Claverol S, Giannone G, Chamma I, Mackereth CD, Poujol C, Choquet D, Sainlos M. Engineering paralog-specific PSD-95 recombinant binders as minimally interfering multimodal probes for advanced imaging techniques. eLife 2024; 13:e69620. [PMID: 38167295 PMCID: PMC10803022 DOI: 10.7554/elife.69620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 12/04/2023] [Indexed: 01/05/2024] Open
Abstract
Despite the constant advances in fluorescence imaging techniques, monitoring endogenous proteins still constitutes a major challenge in particular when considering dynamics studies or super-resolution imaging. We have recently evolved specific protein-based binders for PSD-95, the main postsynaptic scaffold proteins at excitatory synapses. Since the synthetic recombinant binders recognize epitopes not directly involved in the target protein activity, we consider them here as tools to develop endogenous PSD-95 imaging probes. After confirming their lack of impact on PSD-95 function, we validated their use as intrabody fluorescent probes. We further engineered the probes and demonstrated their usefulness in different super-resolution imaging modalities (STED, PALM, and DNA-PAINT) in both live and fixed neurons. Finally, we exploited the binders to enrich at the synapse genetically encoded calcium reporters. Overall, we demonstrate that these evolved binders constitute a robust and efficient platform to selectively target and monitor endogenous PSD-95 using various fluorescence imaging techniques.
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Affiliation(s)
- Charlotte Rimbault
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | - Christelle Breillat
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | - Benjamin Compans
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | - Estelle Toulmé
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | - Filipe Nunes Vicente
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | - Monica Fernandez-Monreal
- University of Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4BordeauxFrance
| | - Patrice Mascalchi
- University of Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4BordeauxFrance
| | - Camille Genuer
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | - Virginia Puente-Muñoz
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | - Isabel Gauthereau
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | - Eric Hosy
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | | | - Gregory Giannone
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | - Ingrid Chamma
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | | | - Christel Poujol
- University of Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4BordeauxFrance
| | - Daniel Choquet
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
| | - Matthieu Sainlos
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297BordeauxFrance
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27
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Altas B, Tuffy LP, Patrizi A, Dimova K, Soykan T, Brandenburg C, Romanowski AJ, Whitten JR, Robertson CD, Khim SN, Crutcher GW, Ambrozkiewicz MC, Yagensky O, Krueger-Burg D, Hammer M, Hsiao HH, Laskowski PR, Dyck L, Puche AC, Sassoè-Pognetto M, Chua JJE, Urlaub H, Jahn O, Brose N, Poulopoulos A. Region-Specific Phosphorylation Determines Neuroligin-3 Localization to Excitatory Versus Inhibitory Synapses. Biol Psychiatry 2023:S0006-3223(23)01799-7. [PMID: 38154503 PMCID: PMC11209832 DOI: 10.1016/j.biopsych.2023.12.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023]
Abstract
BACKGROUND Neuroligin-3 is a postsynaptic adhesion molecule involved in synapse development and function. It is implicated in rare, monogenic forms of autism, and its shedding is critical to the tumor microenvironment of gliomas. While other members of the neuroligin family exhibit synapse-type specificity in localization and function through distinct interactions with postsynaptic scaffold proteins, the specificity of neuroligin-3 synaptic localization remains largely unknown. METHODS We investigated the synaptic localization of neuroligin-3 across regions in mouse and human brain samples after validating antibody specificity in knockout animals. We raised a phospho-specific neuroligin antibody and used phosphoproteomics, cell-based assays, and in utero CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/Cas9) knockout and gene replacement to identify mechanisms that regulate neuroligin-3 localization to distinct synapse types. RESULTS Neuroligin-3 exhibits region-dependent synapse specificity, largely localizing to excitatory synapses in cortical regions and inhibitory synapses in subcortical regions of the brain in both mice and humans. We identified specific phosphorylation of cortical neuroligin-3 at a key binding site for recruitment to inhibitory synapses, while subcortical neuroligin-3 remained unphosphorylated. In vitro, phosphomimetic mutation of that site disrupted neuroligin-3 association with the inhibitory postsynaptic scaffolding protein gephyrin. In vivo, phosphomimetic mutants of neuroligin-3 localized to excitatory postsynapses, while phospho-null mutants localized to inhibitory postsynapses. CONCLUSIONS These data reveal an unexpected region-specific pattern of neuroligin-3 synapse specificity, as well as a phosphorylation-dependent mechanism that regulates its recruitment to either excitatory or inhibitory synapses. These findings add to our understanding of how neuroligin-3 is involved in conditions that may affect the balance of excitation and inhibition.
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Affiliation(s)
- Bekir Altas
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Liam P Tuffy
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Annarita Patrizi
- Department of Neuroscience Rita Levi Montalcini, University of Turin, Turin, Italy
| | - Kalina Dimova
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany; Neuroproteomics Group, Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Tolga Soykan
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Cheryl Brandenburg
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Andrea J Romanowski
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Julia R Whitten
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Colin D Robertson
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Saovleak N Khim
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Garrett W Crutcher
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Mateusz C Ambrozkiewicz
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Oleksandr Yagensky
- Research Group Protein Trafficking in Synaptic Development and Function, Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Dilja Krueger-Burg
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Matthieu Hammer
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - He-Hsuan Hsiao
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Pawel R Laskowski
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Lydia Dyck
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Adam C Puche
- Department of Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland
| | | | - John J E Chua
- Research Group Protein Trafficking in Synaptic Development and Function, Laboratory of Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany; Bioanalytics Group, Institute of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Olaf Jahn
- Neuroproteomics Group, Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany; Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Alexandros Poulopoulos
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, Maryland; Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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28
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Piot L, Heroven C, Bossi S, Zamith J, Malinauskas T, Johnson C, Wennagel D, Stroebel D, Charrier C, Aricescu AR, Mony L, Paoletti P. GluD1 binds GABA and controls inhibitory plasticity. Science 2023; 382:1389-1394. [PMID: 38060673 DOI: 10.1126/science.adf3406] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 10/25/2023] [Indexed: 12/23/2023]
Abstract
Fast synaptic neurotransmission in the vertebrate central nervous system relies primarily on ionotropic glutamate receptors (iGluRs), which drive neuronal excitation, and type A γ-aminobutyric acid receptors (GABAARs), which are responsible for neuronal inhibition. However, the GluD1 receptor, an iGluR family member, is present at both excitatory and inhibitory synapses. Whether and how GluD1 activation may affect inhibitory neurotransmission is unknown. In this work, by using a combination of biochemical, structural, and functional analyses, we demonstrate that GluD1 binds GABA, a previously unknown feature of iGluRs. GluD1 activation produces long-lasting enhancement of GABAergic synaptic currents in the adult mouse hippocampus through a non-ionotropic mechanism that is dependent on trans-synaptic anchoring. The identification of GluD1 as a GABA receptor that controls inhibitory synaptic plasticity challenges the classical dichotomy between glutamatergic and GABAergic receptors.
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Affiliation(s)
- Laura Piot
- Institut de Biologie de l'ENS (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, F-75005 Paris, France
| | | | - Simon Bossi
- Institut de Biologie de l'ENS (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, F-75005 Paris, France
| | - Joseph Zamith
- Institut de Biologie de l'ENS (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, F-75005 Paris, France
| | - Tomas Malinauskas
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Chris Johnson
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Doris Wennagel
- Institut de Biologie de l'ENS (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, F-75005 Paris, France
| | - David Stroebel
- Institut de Biologie de l'ENS (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, F-75005 Paris, France
| | - Cécile Charrier
- Institut de Biologie de l'ENS (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, F-75005 Paris, France
| | | | - Laetitia Mony
- Institut de Biologie de l'ENS (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, F-75005 Paris, France
| | - Pierre Paoletti
- Institut de Biologie de l'ENS (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, F-75005 Paris, France
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29
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Libé-Philippot B, Lejeune A, Wierda K, Louros N, Erkol E, Vlaeminck I, Beckers S, Gaspariunaite V, Bilheu A, Konstantoulea K, Nyitrai H, De Vleeschouwer M, Vennekens KM, Vidal N, Bird TW, Soto DC, Jaspers T, Dewilde M, Dennis MY, Rousseau F, Comoletti D, Schymkowitz J, Theys T, de Wit J, Vanderhaeghen P. LRRC37B is a human modifier of voltage-gated sodium channels and axon excitability in cortical neurons. Cell 2023; 186:5766-5783.e25. [PMID: 38134874 PMCID: PMC10754148 DOI: 10.1016/j.cell.2023.11.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 06/28/2023] [Accepted: 11/27/2023] [Indexed: 12/24/2023]
Abstract
The enhanced cognitive abilities characterizing the human species result from specialized features of neurons and circuits. Here, we report that the hominid-specific gene LRRC37B encodes a receptor expressed in human cortical pyramidal neurons (CPNs) and selectively localized to the axon initial segment (AIS), the subcellular compartment triggering action potentials. Ectopic expression of LRRC37B in mouse CPNs in vivo leads to reduced intrinsic excitability, a distinctive feature of some classes of human CPNs. Molecularly, LRRC37B binds to the secreted ligand FGF13A and to the voltage-gated sodium channel (Nav) β-subunit SCN1B. LRRC37B concentrates inhibitory effects of FGF13A on Nav channel function, thereby reducing excitability, specifically at the AIS level. Electrophysiological recordings in adult human cortical slices reveal lower neuronal excitability in human CPNs expressing LRRC37B. LRRC37B thus acts as a species-specific modifier of human neuron excitability, linking human genome and cell evolution, with important implications for human brain function and diseases.
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Affiliation(s)
- Baptiste Libé-Philippot
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; KUL, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
| | - Amélie Lejeune
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; KUL, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
| | - Keimpe Wierda
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; Electrophysiology Unit, VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium
| | - Nikolaos Louros
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; Department of Cellular and Molecular Medicine, KUL, 3000 Leuven, Belgium
| | - Emir Erkol
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; KUL, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
| | - Ine Vlaeminck
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; Electrophysiology Unit, VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium
| | - Sofie Beckers
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; KUL, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
| | - Vaiva Gaspariunaite
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; KUL, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
| | - Angéline Bilheu
- Université Libre de Bruxelles (ULB), Institute for Interdisciplinary Research (IRIBHM), 1070 Brussels, Belgium
| | - Katerina Konstantoulea
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; Department of Cellular and Molecular Medicine, KUL, 3000 Leuven, Belgium
| | - Hajnalka Nyitrai
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; KUL, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
| | - Matthias De Vleeschouwer
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; Department of Cellular and Molecular Medicine, KUL, 3000 Leuven, Belgium
| | - Kristel M Vennekens
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; KUL, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
| | - Niels Vidal
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; KUL, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium
| | - Thomas W Bird
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Daniela C Soto
- Genome Center, MIND Institute, and Department of Biochemistry & Molecular Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Tom Jaspers
- Laboratory for Therapeutic and Diagnostic Antibodies, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Maarten Dewilde
- Laboratory for Therapeutic and Diagnostic Antibodies, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Megan Y Dennis
- Genome Center, MIND Institute, and Department of Biochemistry & Molecular Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Frederic Rousseau
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; Department of Cellular and Molecular Medicine, KUL, 3000 Leuven, Belgium
| | - Davide Comoletti
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand; Child Health Institute of New Jersey, Rutgers University, New Brunswick, NJ 08901, USA
| | - Joost Schymkowitz
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; Department of Cellular and Molecular Medicine, KUL, 3000 Leuven, Belgium
| | - Tom Theys
- KUL, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium; Research Group Experimental Neurosurgery and Neuroanatomy, KUL, 3000 Leuven, Belgium
| | - Joris de Wit
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; KUL, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium.
| | - Pierre Vanderhaeghen
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium; KUL, Department of Neurosciences, Leuven Brain Institute, 3000 Leuven, Belgium; Université Libre de Bruxelles (ULB), Institute for Interdisciplinary Research (IRIBHM), 1070 Brussels, Belgium.
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Kim SC, Mitchell SJ, Qamar S, Whitcomb DJ, Ruepp MD, St George-Hyslop P, Cho K. Mimicking hypomethylation of FUS requires liquid-liquid phase separation to induce synaptic dysfunctions. Acta Neuropathol Commun 2023; 11:199. [PMID: 38105257 PMCID: PMC10726623 DOI: 10.1186/s40478-023-01703-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 11/29/2023] [Indexed: 12/19/2023] Open
Abstract
The hypomethylation of fused in sarcoma (FUS) in frontotemporal lobar degeneration promotes the formation of irreversible condensates of FUS. However, the mechanisms by which these hypomethylated FUS condensates cause neuronal dysfunction are unknown. Here we report that expression of FUS constructs mimicking hypomethylated FUS causes aberrant dendritic FUS condensates in CA1 neurons. These hypomethylated FUS condensates exhibit spontaneous, and activity induced movement within the dendrite. They impair excitatory synaptic transmission, postsynaptic density-95 expression, and dendritic spine plasticity. These neurophysiological defects are dependent upon both the dendritic localisation of the condensates, and their ability to undergo liquid-liquid phase separation. These results indicate that the irreversible liquid-liquid phase separation is a key component of hypomethylated FUS pathophysiology in sporadic FTLD, and this can cause synapse dysfunction in sporadic FTLD.
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Affiliation(s)
- Seung Chan Kim
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, UK-Dementia Research Institute, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, SE5 9NU, UK
| | - Scott J Mitchell
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, UK-Dementia Research Institute, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, SE5 9NU, UK
| | - Seema Qamar
- Department of Clinical Neurosciences, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | | | - Marc-David Ruepp
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, UK-Dementia Research Institute, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, SE5 9NU, UK
| | - Peter St George-Hyslop
- Department of Clinical Neurosciences, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
- Department of Medicine (Division of Neurology), University Health Network and Tanz Centre for Research In Neurodegenerative Diseases, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 3H2, Canada
- Taub Institute For Research On Alzheimer's Disease and the Aging Brain, Department of Neurology, Columbia University Irving Medical Center, 630 West 168 Street, New York, NY, 10032, USA
| | - Kwangwook Cho
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, UK-Dementia Research Institute, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, SE5 9NU, UK.
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31
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Welle TM, Rajgor D, Garcia JD, Kareemo D, Zych SM, Gookin SE, Martinez TP, Dell’Acqua ML, Ford CP, Kennedy MJ, Smith KR. miRNA-mediated control of gephyrin synthesis drives sustained inhibitory synaptic plasticity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.12.570420. [PMID: 38168421 PMCID: PMC10760056 DOI: 10.1101/2023.12.12.570420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Activity-dependent protein synthesis is crucial for many long-lasting forms of synaptic plasticity. However, our understanding of the translational mechanisms controlling inhibitory synapses is limited. One distinct form of inhibitory long-term potentiation (iLTP) enhances postsynaptic clusters of GABAARs and the primary inhibitory scaffold, gephyrin, to promote sustained synaptic strengthening. While we previously found that persistent iLTP requires mRNA translation, the precise mechanisms controlling gephyrin translation during this process remain unknown. Here, we identify miR153 as a novel regulator of Gphn mRNA translation which controls gephyrin protein levels and synaptic clustering, ultimately impacting GABAergic synaptic structure and function. We find that iLTP induction downregulates miR153, reversing its translational suppression of Gphn mRNA and allowing for increased de novo gephyrin protein synthesis and synaptic clustering during iLTP. Finally, we find that reduced miR153 expression during iLTP is driven by an excitation-transcription coupling pathway involving calcineurin, NFAT and HDACs, which also controls the miRNA-dependent upregulation of GABAARs. Overall, this work delineates a miRNA-dependent post-transcriptional mechanism that controls the expression of the key synaptic scaffold, gephyrin, and may converge with parallel miRNA pathways to coordinate gene upregulation to maintain inhibitory synaptic plasticity.
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Affiliation(s)
- Theresa M. Welle
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
- T.M.W and D.R. contributed equally to this work
| | - Dipen Rajgor
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
- T.M.W and D.R. contributed equally to this work
| | - Joshua D. Garcia
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Dean Kareemo
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Sarah M. Zych
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Sara E. Gookin
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Tyler P. Martinez
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Mark L. Dell’Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Christopher P. Ford
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Matthew J. Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Katharine R. Smith
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
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32
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Olah SS, Kareemo DJ, Buchta WC, Sinnen BL, Miller CN, Actor-Engel HS, Gookin SE, Winborn CS, Kleinjan MS, Crosby KC, Aoto J, Smith KR, Kennedy MJ. Acute reorganization of postsynaptic GABA A receptors reveals the functional impact of molecular nanoarchitecture at inhibitory synapses. Cell Rep 2023; 42:113331. [PMID: 37910506 PMCID: PMC10782565 DOI: 10.1016/j.celrep.2023.113331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 09/01/2023] [Accepted: 10/06/2023] [Indexed: 11/03/2023] Open
Abstract
Neurotransmitter receptors partition into nanometer-scale subdomains within the postsynaptic membrane that are precisely aligned with presynaptic neurotransmitter release sites. While spatial coordination between pre- and postsynaptic elements is observed at both excitatory and inhibitory synapses, the functional significance of this molecular architecture has been challenging to evaluate experimentally. Here we utilized an optogenetic clustering approach to acutely alter the nanoscale organization of the postsynaptic inhibitory scaffold gephyrin while monitoring synaptic function. Gephyrin clustering rapidly enlarged postsynaptic area, laterally displacing GABAA receptors from their normally precise apposition with presynaptic active zones. Receptor displacement was accompanied by decreased synaptic GABAA receptor currents even though presynaptic release probability and the overall abundance and function of synaptic GABAA receptors remained unperturbed. Thus, acutely repositioning neurotransmitter receptors within the postsynaptic membrane profoundly influences synaptic efficacy, establishing the functional importance of precision pre-/postsynaptic molecular coordination at inhibitory synapses.
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Affiliation(s)
- Samantha S Olah
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Dean J Kareemo
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - William C Buchta
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Brooke L Sinnen
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Carley N Miller
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Hannah S Actor-Engel
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Sara E Gookin
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Christina S Winborn
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Mason S Kleinjan
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Kevin C Crosby
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Jason Aoto
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Katharine R Smith
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Matthew J Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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33
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Pol E, Côme E, Merlaud Z, Gouhier J, Russeau M, Scotto-Lomassese S, Moutkine I, Marques X, Lévi S. NKCC1 and KCC2 Chloride Transporters Have Different Membrane Dynamics on the Surface of Hippocampal Neurons. Cells 2023; 12:2363. [PMID: 37830575 PMCID: PMC10571912 DOI: 10.3390/cells12192363] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 09/12/2023] [Accepted: 09/20/2023] [Indexed: 10/14/2023] Open
Abstract
Na-K-2Cl cotransporter 1 (NKCC1) regulates chloride influx in neurons and thereby GABAA receptor activity in normal and pathological conditions. Here, we characterized in hippocampal neurons the membrane expression, distribution and dynamics of exogenous NKCC1a and NKCC1b isoforms and compared them to those of the chloride extruder K-Cl cotransporter 2 (KCC2). We found that NKCC1a and NKCC1b behave quite similarly. NKCC1a/1b but not KCC2 are present along the axon initial segment where they are confined. Moreover, NKCC1a/1b are detected in the somato-dendritic compartment at a lower level than KCC2, where they form fewer, smaller and less compact clusters at perisynaptic and extrasynaptic sites. Interestingly, ~60% of dendritic clusters of NKCC1a/1b are colocalized with KCC2. They are larger and brighter than those devoid of KCC2, suggesting a particular NKCC1a/1b-KCC2 relationship. In agreement with the reduced dendritic clustering of NKCC1a/1b compared with that of KCC2, NKCC1a/1b are more mobile on the dendrite than KCC2, suggesting weaker cytoskeletal interaction. NKCC1a/b are confined to endocytic zones, where they spend more time than KCC2. However, they spend less time in these compartments than at the synapses, suggesting that they can rapidly leave endocytic zones to increase the membrane pool, which can happen in pathological conditions. Thus, NKCC1a/b have different membrane dynamics and clustering from KCC2, which helps to explain their low level in the neuronal membrane, while allowing a rapid increase in the membrane pool under pathological conditions.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Sabine Lévi
- Institut du Fer à Moulin, Institut National de la Santé Et de la Recherche Médicale (INSERM) UMR-S 1270, Sorbonne Université, 75005 Paris, France; (E.P.); (E.C.); (Z.M.); (J.G.); (M.R.); (S.S.-L.); (I.M.); (X.M.)
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34
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Del Rivero Morfin PJ, Chavez DS, Jayaraman S, Yang L, Kochiss AL, Colecraft HM, Liu XS, Marx SO, Rajadhyaksha AM, Ben-Johny M. A Genetically Encoded Actuator Selectively Boosts L-type Calcium Channels in Diverse Physiological Settings. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.22.558856. [PMID: 37790372 PMCID: PMC10542531 DOI: 10.1101/2023.09.22.558856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
L-type Ca 2+ channels (Ca V 1.2/1.3) convey influx of calcium ions (Ca 2+ ) that orchestrate a bevy of biological responses including muscle contraction and gene transcription. Deficits in Ca V 1 function play a vital role in cardiac and neurodevelopmental disorders. Yet conventional pharmacological approaches to upregulate Ca V 1 are limited, as excessive Ca 2+ influx leads to cytotoxicity. Here, we develop a genetically encoded enhancer of Ca V 1.2/1.3 channels (GeeC) to manipulate Ca 2+ entry in distinct physiological settings. Specifically, we functionalized a nanobody that targets the Ca V macromolecular complex by attaching a minimal effector domain from a Ca V enhancer-leucine rich repeat containing protein 10 (Lrrc10). In cardiomyocytes, GeeC evoked a 3-fold increase in L-type current amplitude. In neurons, GeeC augmented excitation-transcription (E-T) coupling. In all, GeeC represents a powerful strategy to boost Ca V 1.2/1.3 function in distinct physiological settings and, in so doing, lays the groundwork to illuminate new insights on neuronal and cardiac physiology and disease.
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35
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Hoshino N, Kanadome T, Takasugi T, Itoh M, Kaneko R, Inoue YU, Inoue T, Hirabayashi T, Watanabe M, Matsuda T, Nagai T, Tarusawa E, Yagi T. Visualization of trans homophilic interaction of clustered protocadherin in neurons. Proc Natl Acad Sci U S A 2023; 120:e2301003120. [PMID: 37695902 PMCID: PMC10515168 DOI: 10.1073/pnas.2301003120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 07/20/2023] [Indexed: 09/13/2023] Open
Abstract
Clustered protocadherin (Pcdh) functions as a cell recognition molecule through the homophilic interaction in the central nervous system. However, its interactions have not yet been visualized in neurons. We previously reported PcdhγB2-Förster resonance energy transfer (FRET) probes to be applicable only to cell lines. Herein, we designed γB2-FRET probes by fusing FRET donor and acceptor fluorescent proteins to a single γB2 molecule and succeeded in visualizing γB2 homophilic interaction in cultured hippocampal neurons. The γB2-FRET probe localized in the soma and neurites, and FRET signals, which were observed at contact sites between neurites, eliminated by ethylene glycol tetraacetic acid (EGTA) addition. Live imaging revealed that the FRET-negative γB2 signals rapidly moved along neurites and soma, whereas the FRET-positive signals remained in place. We observed that the γB2 proteins at synapses rarely interact homophilically. The γB2-FRET probe might allow us to elucidate the function of the homophilic interaction and the cell recognition mechanism.
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Affiliation(s)
- Natsumi Hoshino
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
| | - Takashi Kanadome
- Department of Biomolecular Science and Engineering, SANKEN, Osaka University, Ibaraki, Osaka567-0047, Japan
- Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama332-0012, Japan
| | - Tomomi Takasugi
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
| | - Mizuho Itoh
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
| | - Ryosuke Kaneko
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
| | - Yukiko U. Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo187-8501, Japan
| | - Takayoshi Inoue
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo187-8501, Japan
| | - Takahiro Hirabayashi
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
- Clinical Medicine Research Laboratory, Shonan University of Medical Sciences, Yokohama244-0806, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Faculty of Medicine, Hokkaido University, Sapporo, Hokkaido060-8638, Japan
| | - Tomoki Matsuda
- Department of Biomolecular Science and Engineering, SANKEN, Osaka University, Ibaraki, Osaka567-0047, Japan
| | - Takeharu Nagai
- Department of Biomolecular Science and Engineering, SANKEN, Osaka University, Ibaraki, Osaka567-0047, Japan
| | - Etsuko Tarusawa
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
| | - Takeshi Yagi
- KOKORO-Biology Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka565-0871, Japan
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36
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Rivera JF, Weng W, Huang H, Rao S, Herring BE, Arnold DB. ATLAS: A rationally designed anterograde transsynaptic tracer. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.12.557425. [PMID: 37745471 PMCID: PMC10515852 DOI: 10.1101/2023.09.12.557425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Neural circuits, which constitute the substrate for brain processing, can be traced in the retrograde direction, from postsynaptic to presynaptic cells, using methods based on introducing modified rabies virus into genetically marked cell types. These methods have revolutionized the field of neuroscience. However, similarly reliable, transsynaptic, and non-toxic methods to trace circuits in the anterograde direction are not available. Here, we describe such a method based on an antibody-like protein selected against the extracellular N-terminus of the AMPA receptor subunit GluA1 (AMPA.FingR). ATLAS (Anterograde Transsynaptic Label based on Antibody-like Sensors) is engineered to release the AMPA.FingR and its payload, which can include Cre recombinase, from presynaptic sites into the synaptic cleft, after which it binds to GluA1, enters postsynaptic cells through endocytosis and subsequently carries its payload to the nucleus. Testing in vivo and in dissociated cultures shows that ATLAS mediates monosynaptic tracing from genetically determined cells that is strictly anterograde, synaptic, and non-toxic. Moreover, ATLAS shows activity dependence, which may make tracing active circuits that underlie specific behaviors possible.
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Affiliation(s)
- Jacqueline F. Rivera
- Department of Biology, University of Southern California, Los Angeles, CA 90089
- These authors contributed equally
| | - Weiguang Weng
- Department of Biology, University of Southern California, Los Angeles, CA 90089
- These authors contributed equally
| | - Haoyang Huang
- Department of Biology, University of Southern California, Los Angeles, CA 90089
- These authors contributed equally
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089
| | - Sadhna Rao
- Department of Biology, University of Southern California, Los Angeles, CA 90089
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089
| | - Bruce E. Herring
- Department of Biology, University of Southern California, Los Angeles, CA 90089
| | - Don B. Arnold
- Department of Biology, University of Southern California, Los Angeles, CA 90089
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37
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David TI, Pestov NB, Korneenko TV, Barlev NA. Non-Immunoglobulin Synthetic Binding Proteins for Oncology. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:1232-1247. [PMID: 37770391 DOI: 10.1134/s0006297923090043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/01/2023] [Accepted: 08/01/2023] [Indexed: 09/30/2023]
Abstract
Extensive application of technologies like phage display in screening peptide and protein combinatorial libraries has not only facilitated creation of new recombinant antibodies but has also significantly enriched repertoire of the protein binders that have polypeptide scaffolds without homology to immunoglobulins. These innovative synthetic binding protein (SBP) platforms have grown in number and now encompass monobodies/adnectins, DARPins, lipocalins/anticalins, and a variety of miniproteins such as affibodies and knottins, among others. They serve as versatile modules for developing complex affinity tools that hold promise in both diagnostic and therapeutic settings. An optimal scaffold typically has low molecular weight, minimal immunogenicity, and demonstrates resistance against various challenging conditions, including proteolysis - making it potentially suitable for peroral administration. Retaining functionality under reducing intracellular milieu is also advantageous. However, paramount to its functionality is the scaffold's ability to tolerate mutations across numerous positions, allowing for the formation of a sufficiently large target binding region. This is achieved through the library construction, screening, and subsequent expression in an appropriate system. Scaffolds that exhibit high thermodynamic stability are especially coveted by the developers of new SBPs. These are steadily making their way into clinical settings, notably as antagonists of oncoproteins in signaling pathways. This review surveys the diverse landscape of SBPs, placing particular emphasis on the inhibitors targeting the oncoprotein KRAS, and highlights groundbreaking opportunities for SBPs in oncology.
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Affiliation(s)
- Temitope I David
- Institute of Biomedical Chemistry, Moscow, 119121, Russia
- Laboratory of Molecular Oncology, Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, 141701, Russia
| | - Nikolay B Pestov
- Institute of Biomedical Chemistry, Moscow, 119121, Russia.
- Laboratory of Tick-Borne Encephalitis and Other Viral Encephalitides, Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products, Russian Academy of Sciences, Moscow, 108819, Russia
- Group of Cross-Linking Enzymes, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
| | - Tatyana V Korneenko
- Group of Cross-Linking Enzymes, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia
| | - Nikolai A Barlev
- Institute of Biomedical Chemistry, Moscow, 119121, Russia
- Laboratory of Tick-Borne Encephalitis and Other Viral Encephalitides, Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products, Russian Academy of Sciences, Moscow, 108819, Russia
- Institute of Cytology Russian Academy of Sciences, St.-Petersburg, 194064, Russia
- School of Medicine, Nazarbayev University, Astana, 010000, Kazakhstan
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38
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Larsen ME, Buonarati OR, Qian H, Hell JW, Bayer KU. Stimulating β-adrenergic receptors promotes synaptic potentiation by switching CaMKII movement from LTD to LTP mode. J Biol Chem 2023; 299:104706. [PMID: 37061000 PMCID: PMC10200978 DOI: 10.1016/j.jbc.2023.104706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 03/31/2023] [Accepted: 04/06/2023] [Indexed: 04/17/2023] Open
Abstract
Learning, memory, and cognition are thought to require synaptic plasticity, specifically including hippocampal long-term potentiation and depression (LTP and LTD). LTP versus LTD is induced by high-frequency stimulation versus low-frequency, but stimulating β-adrenergic receptors (βARs) enables LTP induction also by low-frequency stimulation (1 Hz) or theta frequencies (∼5 Hz) that do not cause plasticity by themselves. In contrast to high-frequency stimulation-LTP, such βAR-LTP requires Ca2+-flux through L-type voltage-gated Ca2+-channels, not N-methyl-D-aspartate-type glutamate receptors. Surprisingly, we found that βAR-LTP still required a nonionotropic scaffolding function of the N-methyl-D-aspartate-type glutamate receptor: the stimulus-induced binding of the Ca2+/calmodulin-dependent protein kinase II (CaMKII) to its GluN2B subunit that mediates CaMKII movement to excitatory synapses. In hippocampal neurons, β-adrenergic stimulation with isoproterenol (Iso) transformed LTD-type CaMKII movement to LTP-type movement, resulting in CaMKII movement to excitatory instead of inhibitory synapses. Additionally, Iso enabled induction of a major cell-biological feature of LTP in response to LTD stimuli: increased surface expression of GluA1 fused with super-ecliptic pHluorein. Like for βAR-LTP in hippocampal slices, the Iso effects on CaMKII movement and surface expression of GluA1 fused with super-ecliptic pHluorein involved L-type Ca2+-channels and specifically required β2-ARs. Taken together, these results indicate that Iso transforms LTD stimuli to LTP signals by switching CaMKII movement and GluN2B binding to LTP mode.
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Affiliation(s)
- Matthew E Larsen
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Program in Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Olivia R Buonarati
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Hai Qian
- Department of Pharmacology, University of Iowa, Iowa City, Iowa, USA
| | - Johannes W Hell
- Department of Pharmacology, University of Iowa, Iowa City, Iowa, USA; Department of Pharmacology, University of California at Davis, Davis, California, USA.
| | - K Ulrich Bayer
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Program in Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
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Parisi MJ, Aimino MA, Mosca TJ. A conditional strategy for cell-type-specific labeling of endogenous excitatory synapses in Drosophila. CELL REPORTS METHODS 2023; 3:100477. [PMID: 37323572 PMCID: PMC10261928 DOI: 10.1016/j.crmeth.2023.100477] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 02/28/2023] [Accepted: 04/19/2023] [Indexed: 06/17/2023]
Abstract
Chemical neurotransmission occurs at specialized contacts where neurotransmitter release machinery apposes neurotransmitter receptors to underlie circuit function. A series of complex events underlies pre- and postsynaptic protein recruitment to neuronal connections. To better study synaptic development in individual neurons, we need cell-type-specific strategies to visualize endogenous synaptic proteins. Although presynaptic strategies exist, postsynaptic proteins remain less studied because of a paucity of cell-type-specific reagents. To study excitatory postsynapses with cell-type specificity, we engineered dlg1[4K], a conditionally labeled marker of Drosophila excitatory postsynaptic densities. With binary expression systems, dlg1[4K] labels central and peripheral postsynapses in larvae and adults. Using dlg1[4K], we find that distinct rules govern postsynaptic organization in adult neurons, multiple binary expression systems can concurrently label pre- and postsynapse in a cell-type-specific manner, and neuronal DLG1 can sometimes localize presynaptically. These results validate our strategy for conditional postsynaptic labeling and demonstrate principles of synaptic organization.
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Affiliation(s)
- Michael J. Parisi
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Michael A. Aimino
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Timothy J. Mosca
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
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Tullis JE, Bayer KU. Distinct synaptic pools of DAPK1 differentially regulate activity-dependent synaptic CaMKII accumulation. iScience 2023; 26:106723. [PMID: 37216104 PMCID: PMC10192646 DOI: 10.1016/j.isci.2023.106723] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/18/2023] [Accepted: 04/19/2023] [Indexed: 05/24/2023] Open
Abstract
The death-associated protein kinase 1 (DAPK1) regulates the synaptic movement of the Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII). Synaptic CaMKII accumulation is mediated via binding to the NMDA-receptor subunit GluN2B and is required for long-term potentiation (LTP). By contrast, long-term depression (LTD) instead requires specific suppression of this movement, which is mediated by competitive DAPK1 binding to GluN2B. We find here that DAPK1 localizes to synapses via two distinct mechanisms: basal localization requires F-actin, but retention of DAPK1 at synapses during LTD requires an additional binding mode, likely to GluN2B. While F-actin binding mediates DAPK1 enrichment at synapses, it is not sufficient to suppress synaptic CaMKII movement. However, it is a prerequisite that enables the additional LTD-specific binding mode of DAPK1, which in turn mediates suppression of the CaMKII movement. Thus, both modes of synaptic DAPK1 localization work together to regulate synaptic CaMKII localization and thereby synaptic plasticity.
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Affiliation(s)
- Jonathan E. Tullis
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - K. Ulrich Bayer
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Program in Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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Mackay JP, Smith-Dijak AI, Koch ET, Zhang P, Fung E, Nassrallah WB, Buren C, Schmidt M, Hayden MR, Raymond LA. Axonal ER Ca 2+ Release Selectively Enhances Activity-Independent Glutamate Release in a Huntington Disease Model. J Neurosci 2023; 43:3743-3763. [PMID: 36944490 PMCID: PMC10198457 DOI: 10.1523/jneurosci.1593-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 03/08/2023] [Accepted: 03/15/2023] [Indexed: 03/23/2023] Open
Abstract
Action potential (AP)-independent (miniature) neurotransmission occurs at all chemical synapses but remains poorly understood, particularly in pathologic contexts. Axonal endoplasmic reticulum (ER) Ca2+ stores are thought to influence miniature neurotransmission, and aberrant ER Ca2+ handling is implicated in progression of Huntington disease (HD). Here, we report elevated mEPSC frequencies in recordings from YAC128 mouse (HD-model) neurons (from cortical cultures and striatum-containing brain slices, both from male and female animals). Pharmacological experiments suggest that this is mediated indirectly by enhanced tonic ER Ca2+ release. Calcium imaging, using an axon-localized sensor, revealed slow AP-independent ER Ca2+ release waves in both YAC128 and WT cultures. These Ca2+ waves occurred at similar frequencies in both genotypes but spread less extensively and were of lower amplitude in YAC128 axons, consistent with axonal ER Ca2+ store depletion. Surprisingly, basal cytosolic Ca2+ levels were lower in YAC128 boutons and YAC128 mEPSCs were less sensitive to intracellular Ca2+ chelation. Together, these data suggest that elevated miniature glutamate release in YAC128 cultures is associated with axonal ER Ca2+ depletion but not directly mediated by ER Ca2+ release into the cytoplasm. In contrast to increased mEPSC frequencies, cultured YAC128 cortical neurons showed less frequent AP-dependent (spontaneous) Ca2+ events in soma and axons, although evoked glutamate release detected by an intensity-based glutamate-sensing fluorescence reporter in brain slices was similar between genotypes. Our results indicate that axonal ER dysfunction selectively elevates miniature glutamate release from cortical terminals in HD. This, together with reduced spontaneous cortical neuron firing, may cause a shift from activity-dependent to -independent glutamate release in HD, with potential implications for fidelity and plasticity of cortical excitatory signaling.SIGNIFICANCE STATEMENT Miniature neurotransmitter release persists at all chemical neuronal synapses in the absence of action potential firing but remains poorly understood, particularly in disease states. We show enhanced miniature glutamate release from cortical neurons in the YAC128 mouse Huntington disease model. This effect is mediated by axonal ER Ca2+ store depletion, but is not obviously due to elevated ER-to-cytosol Ca2+ release. Conversely, YAC128 cortical pyramidal neurons fired fewer action potentials and evoked cortical glutamate release was similar between WT an YAC128 preparations, indicating axonal ER depletion selectively enhances miniature glutamate release in YAC128 mice. These results extend our understanding of action potential independent neurotransmission and highlight a potential involvement of elevated miniature glutamate release in Huntington disease pathology.
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Affiliation(s)
- James P Mackay
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health
| | - Amy I Smith-Dijak
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health
- Graduate Program in Neuroscience
| | - Ellen T Koch
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health
- Graduate Program in Neuroscience
| | - Peng Zhang
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106
| | - Evan Fung
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health
| | - Wissam B Nassrallah
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health
- MD/PhD Program
| | - Caodu Buren
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health
- Graduate Program in Neuroscience
| | - Mandi Schmidt
- Graduate Program in Neuroscience
- Centre for Molecular Medicine and Therapeutics, British Columbia Children's Hospital Research Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, British Columbia Children's Hospital Research Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Lynn A Raymond
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health
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Parker SS, Ly KT, Grant AD, Sweetland J, Wang AM, Parker JD, Roman MR, Saboda K, Roe DJ, Padi M, Wolgemuth CW, Langlais P, Mouneimne G. EVL and MIM/MTSS1 regulate actin cytoskeletal remodeling to promote dendritic filopodia in neurons. J Cell Biol 2023; 222:e202106081. [PMID: 36828364 PMCID: PMC9998662 DOI: 10.1083/jcb.202106081] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 11/22/2022] [Accepted: 01/20/2023] [Indexed: 02/25/2023] Open
Abstract
Dendritic spines are the postsynaptic compartment of a neuronal synapse and are critical for synaptic connectivity and plasticity. A developmental precursor to dendritic spines, dendritic filopodia (DF), facilitate synapse formation by sampling the environment for suitable axon partners during neurodevelopment and learning. Despite the significance of the actin cytoskeleton in driving these dynamic protrusions, the actin elongation factors involved are not well characterized. We identified the Ena/VASP protein EVL as uniquely required for the morphogenesis and dynamics of DF. Using a combination of genetic and optogenetic manipulations, we demonstrated that EVL promotes protrusive motility through membrane-direct actin polymerization at DF tips. EVL forms a complex at nascent protrusions and DF tips with MIM/MTSS1, an I-BAR protein important for the initiation of DF. We proposed a model in which EVL cooperates with MIM to coalesce and elongate branched actin filaments, establishing the dynamic lamellipodia-like architecture of DF.
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Affiliation(s)
- Sara S. Parker
- Department of Cellular and Molecular Medicine, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Kenneth Tran Ly
- Department of Cellular and Molecular Medicine, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Adam D. Grant
- Cancer Biology Program, University of Arizona Cancer Center, Tucson, AZ, USA
| | - Jillian Sweetland
- Department of Cellular and Molecular Medicine, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Ashley M. Wang
- Department of Cellular and Molecular Medicine, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - James D. Parker
- Department of Cellular and Molecular Medicine, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Mackenzie R. Roman
- Division of Endocrinology, Department of Medicine, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Kathylynn Saboda
- University of Arizona Cancer Center and Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - Denise J. Roe
- University of Arizona Cancer Center and Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
| | - Megha Padi
- Cancer Biology Program, University of Arizona Cancer Center, Tucson, AZ, USA
- Department of Molecular and Cellular Biology, College of Science, University of Arizona, Tucson, AZ, USA
| | - Charles W. Wolgemuth
- University of Arizona Cancer Center and Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA
- Department of Molecular and Cellular Biology, College of Science, University of Arizona, Tucson, AZ, USA
- Department of Physics, College of Science, University of Arizona, Tucson, AZ, USA
- Johns Hopkins Physical Sciences-Oncology Center, Johns Hopkins University, Baltimore, MD, USA
| | - Paul Langlais
- Division of Endocrinology, Department of Medicine, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Ghassan Mouneimne
- Department of Cellular and Molecular Medicine, College of Medicine, University of Arizona, Tucson, AZ, USA
- Cancer Biology Program, University of Arizona Cancer Center, Tucson, AZ, USA
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Kleinjan MS, Buchta WC, Ogelman R, Hwang IW, Kuwajima M, Hubbard DD, Kareemo DJ, Prikhodko O, Olah SL, Gomez Wulschner LE, Abraham WC, Franco SJ, Harris KM, Oh WC, Kennedy MJ. Dually innervated dendritic spines develop in the absence of excitatory activity and resist plasticity through tonic inhibitory crosstalk. Neuron 2023; 111:362-371.e6. [PMID: 36395772 PMCID: PMC9899020 DOI: 10.1016/j.neuron.2022.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 07/13/2022] [Accepted: 10/31/2022] [Indexed: 11/17/2022]
Abstract
Dendritic spines can be directly connected to both inhibitory and excitatory presynaptic terminals, resulting in nanometer-scale proximity of opposing synaptic functions. While dually innervated spines (DiSs) are observed throughout the central nervous system, their developmental timeline and functional properties remain uncharacterized. Here we used a combination of serial section electron microscopy, live imaging, and local synapse activity manipulations to investigate DiS development and function in rodent hippocampus. Dual innervation occurred early in development, even on spines where the excitatory input was locally silenced. Synaptic NMDA receptor currents were selectively reduced at DiSs through tonic GABAB receptor signaling. Accordingly, spine enlargement normally associated with long-term potentiation on singly innervated spines (SiSs) was blocked at DiSs. Silencing somatostatin interneurons or pharmacologically blocking GABABRs restored NMDA receptor function and structural plasticity to levels comparable to neighboring SiSs. Thus, hippocampal DiSs are stable structures where function and plasticity are potently regulated by nanometer-scale GABAergic signaling.
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Affiliation(s)
- Mason S Kleinjan
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - William C Buchta
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Roberto Ogelman
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - In-Wook Hwang
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Masaaki Kuwajima
- Department of Neuroscience, University of Texas at Austin, Austin, TX 78712, USA
| | - Dusten D Hubbard
- Department of Neuroscience, University of Texas at Austin, Austin, TX 78712, USA
| | - Dean J Kareemo
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Olga Prikhodko
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Samantha L Olah
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Luis E Gomez Wulschner
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Santos J Franco
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Kristen M Harris
- Department of Neuroscience, University of Texas at Austin, Austin, TX 78712, USA
| | - Won Chan Oh
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - Matthew J Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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Lateral Diffusion of NKCC1 Contributes to Chloride Homeostasis in Neurons and Is Rapidly Regulated by the WNK Signaling Pathway. Cells 2023; 12:cells12030464. [PMID: 36766805 PMCID: PMC9914440 DOI: 10.3390/cells12030464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/27/2023] [Accepted: 01/28/2023] [Indexed: 02/04/2023] Open
Abstract
An upregulation of the Na+-K+-2Cl- cotransporter NKCC1, the main chloride importer in mature neurons, can lead to depolarizing/excitatory responses mediated by GABA type A receptors (GABAARs) and, thus, to hyperactivity. Understanding the regulatory mechanisms of NKCC1 would help prevent intra-neuronal chloride accumulation that occurs in pathologies with defective inhibition. The cell mechanisms regulating NKCC1 are poorly understood. Here, we report in mature hippocampal neurons that GABAergic activity controls the membrane diffusion and clustering of NKCC1 via the chloride-sensitive WNK lysine deficient protein kinase 1 (WNK1) and the downstream Ste20 Pro-line Asparagine Rich Kinase (SPAK) kinase that directly phosphorylates NKCC1 on key threonine residues. At rest, this signaling pathway has little effect on intracellular Cl- concentration, but it participates in the elevation of intraneuronal Cl- concentration in hyperactivity conditions associated with an up-regulation of NKCC1. The fact that the main chloride exporter, the K+-Cl- cotransporter KCC2, is also regulated in mature neurons by the WNK1 pathway indicates that this pathway will be a target of choice in the pathology.
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45
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Quantitative Fluorescence Analysis Reveals Dendrite-Specific Thalamocortical Plasticity in L5 Pyramidal Neurons during Learning. J Neurosci 2023; 43:584-600. [PMID: 36639912 PMCID: PMC9888508 DOI: 10.1523/jneurosci.1372-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/28/2022] [Accepted: 11/23/2022] [Indexed: 12/14/2022] Open
Abstract
High-throughput anatomic data can stimulate and constrain new hypotheses about how neural circuits change in response to experience. Here, we use fluorescence-based reagents for presynaptic and postsynaptic labeling to monitor changes in thalamocortical synapses onto different compartments of layer 5 (L5) pyramidal (Pyr) neurons in somatosensory (barrel) cortex from mixed-sex mice during whisker-dependent learning (Audette et al., 2019). Using axonal fills and molecular-genetic tags for synapse identification in fixed tissue from Rbp4-Cre transgenic mice, we found that thalamocortical synapses from the higher-order posterior medial thalamic nucleus showed rapid morphologic changes in both presynaptic and postsynaptic structures at the earliest stages of sensory association training. Detected increases in thalamocortical synaptic size were compartment specific, occurring selectively in the proximal dendrites onto L5 Pyr and not at inputs onto their apical tufts in L1. Both axonal and dendritic changes were transient, normalizing back to baseline as animals became expert in the task. Anatomical measurements were corroborated by electrophysiological recordings at different stages of training. Thus, fluorescence-based analysis of input- and target-specific synapses can reveal compartment-specific changes in synapse properties during learning.SIGNIFICANCE STATEMENT Synaptic changes underlie the cellular basis of learning, experience, and neurologic diseases. Neuroanatomical methods to assess synaptic plasticity can provide critical spatial information necessary for building models of neuronal computations during learning and experience but are technically and fiscally intensive. Here, we describe a confocal fluorescence microscopy-based analytical method to assess input, cell type, and dendritic location-specific synaptic plasticity in a sensory learning assay. Our method not only confirms prior electrophysiological measurements but allows us to predict functional strength of synapses in a pathway-specific manner. Our findings also indicate that changes in primary sensory cortices are transient, occurring during early learning. Fluorescence-based synapse identification can be an efficient and easily adopted approach to study synaptic changes in a variety of experimental paradigms.
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Ruiz-Reig N, García-Sánchez D, Schakman O, Gailly P, Tissir F. Inhibitory synapse dysfunction and epileptic susceptibility associated with KIF2A deletion in cortical interneurons. Front Mol Neurosci 2023; 15:1110986. [PMID: 36733270 PMCID: PMC9887042 DOI: 10.3389/fnmol.2022.1110986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 12/30/2022] [Indexed: 01/18/2023] Open
Abstract
Malformation of cortical development (MCD) is a family of neurodevelopmental disorders, which usually manifest with intellectual disability and early-life epileptic seizures. Mutations in genes encoding microtubules (MT) and MT-associated proteins are one of the most frequent causes of MCD in humans. KIF2A is an atypical kinesin that depolymerizes MT in ATP-dependent manner and regulates MT dynamics. In humans, single de novo mutations in KIF2A are associated with MCD with epileptic seizures, posterior pachygyria, microcephaly, and partial agenesis of corpus callosum. In this study, we conditionally ablated KIF2A in forebrain inhibitory neurons and assessed its role in development and function of inhibitory cortical circuits. We report that adult mice with specific deletion of KIF2A in GABAergic interneurons display abnormal behavior and increased susceptibility to epilepsy. KIF2A is essential for tangential migration of cortical interneurons, their positioning in the cerebral cortex, and for formation of inhibitory synapses in vivo. Our results shed light on how KIF2A deregulation triggers functional alterations in neuronal circuitries and contributes to epilepsy.
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Affiliation(s)
- Nuria Ruiz-Reig
- Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium,*Correspondence: Nuria Ruiz-Reig, Fadel Tissir, ;
| | | | - Olivier Schakman
- Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Philippe Gailly
- Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Fadel Tissir
- Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium,College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar,*Correspondence: Nuria Ruiz-Reig, Fadel Tissir, ;
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47
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mGluR5 is transiently confined in perisynaptic nanodomains to shape synaptic function. Nat Commun 2023; 14:244. [PMID: 36646691 PMCID: PMC9842668 DOI: 10.1038/s41467-022-35680-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 12/19/2022] [Indexed: 01/18/2023] Open
Abstract
The unique perisynaptic distribution of postsynaptic metabotropic glutamate receptors (mGluRs) at excitatory synapses is predicted to directly shape synaptic function, but mechanistic insight into how this distribution is regulated and impacts synaptic signaling is lacking. We used live-cell and super-resolution imaging approaches, and developed molecular tools to resolve and acutely manipulate the dynamic nanoscale distribution of mGluR5. Here we show that mGluR5 is dynamically organized in perisynaptic nanodomains that localize close to, but not in the synapse. The C-terminal domain of mGluR5 critically controlled perisynaptic confinement and prevented synaptic entry. We developed an inducible interaction system to overcome synaptic exclusion of mGluR5 and investigate the impact on synaptic function. We found that mGluR5 recruitment to the synapse acutely increased synaptic calcium responses. Altogether, we propose that transient confinement of mGluR5 in perisynaptic nanodomains allows flexible modulation of synaptic function.
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48
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Guerrier C, Dellazizzo Toth T, Galtier N, Haas K. An Algorithm Based on a Cable-Nernst Planck Model Predicting Synaptic Activity throughout the Dendritic Arbor with Micron Specificity. Neuroinformatics 2023; 21:207-220. [PMID: 36348198 DOI: 10.1007/s12021-022-09609-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/02/2022] [Indexed: 11/09/2022]
Abstract
Recent technological advances have enabled the recording of neurons in intact circuits with a high spatial and temporal resolution, creating the need for modeling with the same precision. In particular, the development of ultra-fast two-photon microscopy combined with fluorescence-based genetically-encoded Ca2+-indicators allows capture of full-dendritic arbor and somatic responses associated with synaptic input and action potential output. The complexity of dendritic arbor structures and distributed patterns of activity over time results in the generation of incredibly rich 4D datasets that are challenging to analyze (Sakaki et al. in Frontiers in Neural Circuits 14:33, 2020). Interpreting neural activity from fluorescence-based Ca2+ biosensors is challenging due to non-linear interactions between several factors influencing intracellular calcium ion concentration and its binding to sensors, including the ionic dynamics driven by diffusion, electrical gradients and voltage-gated conductances. To investigate those dynamics, we designed a model based on a Cable-like equation coupled to the Nernst-Planck equations for ionic fluxes in electrolytes. We employ this model to simulate signal propagation and ionic electrodiffusion across a dendritic arbor. Using these simulation results, we then designed an algorithm to detect synapses from Ca2+ imaging datasets. We finally apply this algorithm to experimental Ca2+-indicator datasets from neurons expressing jGCaMP7s (Dana et al. in Nature Methods 16:649-657, 2019), using full-dendritic arbor sampling in vivo in the Xenopus laevis optic tectum using fast random-access two-photon microscopy. Our model reproduces the dynamics of visual stimulus-evoked jGCaMP7s-mediated calcium signals observed experimentally, and the resulting algorithm allows prediction of the location of synapses across the dendritic arbor. Our study provides a way to predict synaptic activity and location on dendritic arbors, from fluorescence data in the full dendritic arbor of a neuron recorded in the intact and awake developing vertebrate brain.
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Affiliation(s)
- Claire Guerrier
- Université Côte d'azur, LJAD, CNRS UMR7351, Nice, France. .,CNRS - IRL3457, CRM, Université de Montréal, Montréal, Canada.
| | | | | | - Kurt Haas
- Djavad Mowafaghian Centre for Brain Health, UBC - Vancouver, Vancouver, Canada
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49
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Kida H, Kawakami R, Sakai K, Otaku H, Imamura K, Han TZ, Sakimoto Y, Mitsushima D. Motor training promotes both synaptic and intrinsic plasticity of layer V pyramidal neurons in the primary motor cortex. J Physiol 2023; 601:335-353. [PMID: 36515167 DOI: 10.1113/jp283755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 11/23/2022] [Indexed: 12/15/2022] Open
Abstract
Layer V neurons in the primary motor cortex (M1) are important for motor skill learning. Since pretreatment of either CNQX or APV in rat M1 layer V impaired rotor rod learning, we analysed training-induced synaptic plasticity by whole-cell patch-clamp technique in acute brain slices. Rats trained for 1 day showed a decrease in small inhibitory postsynaptic current (mIPSC) frequency and an increase in the paired-pulse ratio of evoked IPSCs, suggesting a transient decrease in presynaptic GABA release in the early phase. Rats trained for 2 days showed an increase in miniature excitatory postsynaptic current (mEPSC) amplitudes/frequency and elevated AMPA/NMDA ratios, suggesting a long-term strengthening of AMPA receptor-mediated excitatory synapses. Importantly, rotor rod performance in trained rats was correlated with the mean mEPSC amplitude and the frequency obtained from that animal. In current-clamp analysis, 1-day-trained rats transiently decreased the current-induced firing rate, while 2-day-trained rats returned to pre-training levels, suggesting dynamic changes in intrinsic properties. Furthermore, western blot analysis of layer V detected decreased phosphorylation of Ser408-409 in GABAA receptor β3 subunits in 1-day-trained rats, and increased phosphorylation of Ser831 in AMPA receptor GluA1 subunits in 2-day-trained rats. Finally, live-imaging analysis of Thy1-YFP transgenic mice showed that the training rapidly recruited a substantial number of spines for long-term plasticity in M1 layer V neurons. Taken together, these results indicate that motor training induces complex and diverse plasticity in M1 layer V pyramidal neurons. KEY POINTS: Here we examined motor training-induced synaptic and intrinsic plasticity of layer V pyramidal neurons in the primary motor cortex. The training reduced presynaptic GABA release in the early phase, but strengthened AMPA receptor-mediated excitatory synapses in the later phase: acquired motor performance after training correlated with the strength of excitatory synapses rather than inhibitory synapses. As to the intrinsic property, the training transiently decreased the firing rate in the early phase, but returned to pre-training levels in the later phase. Western blot analysis detected decreased phosphorylation of Ser408-409 in GABAA receptor β3 subunits in the acute phase, and increased phosphorylation of Ser831 in AMPA receptor GluA1 subunits in the later phase. Live-imaging analysis of Thy1-YFP transgenic mice showed rapid and long-term spine plasticity in M1 layer V neurons, suggesting training-induced increases in self-entropy per spine.
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Affiliation(s)
- H Kida
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - R Kawakami
- Department of Molecular Medicine for Pathogenesis, Graduate School of Medicine, Ehime University, Ehime, Japan
| | - K Sakai
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - H Otaku
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - K Imamura
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - Thiri-Zin Han
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - Y Sakimoto
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan
| | - Dai Mitsushima
- Department of Physiology, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan.,The Research Institute for Time Studies, Yamaguchi University, Yamaguchi, Japan
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Frank M, Nabb AT, Gilbert SP, Bentley M. Propofol attenuates kinesin-mediated axonal vesicle transport and fusion. Mol Biol Cell 2022; 33:ar119. [PMID: 36103253 PMCID: PMC9634964 DOI: 10.1091/mbc.e22-07-0276] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Propofol is a widely used general anesthetic, yet the understanding of its cellular effects is fragmentary. General anesthetics are not as innocuous as once believed and have a wide range of molecular targets that include kinesin motors. Propofol, ketamine, and etomidate reduce the distances that Kinesin-1 KIF5 and Kinesin-2 KIF3 travel along microtubules in vitro. These transport kinesins are highly expressed in the CNS, and their dysfunction leads to a range of human pathologies including neurodevelopmental and neurodegenerative diseases. While in vitro data suggest that general anesthetics may disrupt kinesin transport in neurons, this hypothesis remains untested. Here we find that propofol treatment of hippocampal neurons decreased vesicle transport mediated by Kinesin-1 KIF5 and Kinesin-3 KIF1A ∼25-60%. Propofol treatment delayed delivery of the KIF5 cargo NgCAM to the distal axon. Because KIF1A participates in axonal transport of presynaptic vesicles, we tested whether prolonged propofol treatment affects synaptic vesicle fusion mediated by VAMP2. The data show that propofol-induced transport delay causes a significant decrease in vesicle fusion in distal axons. These results are the first to link a propofol-induced delay in neuronal trafficking to a decrease in axonal vesicle fusion, which may alter physiological function during and after anesthesia.
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Affiliation(s)
- Madeline Frank
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Alec T. Nabb
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Susan P. Gilbert
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Marvin Bentley
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180,*Address correspondence to: Marvin Bentley ()
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