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Hofbauer B, Zandawala M, Reinhard N, Rieger D, Werner C, Evers JF, Wegener C. The neuropeptide pigment-dispersing factor signals independently of Bruchpilot-labelled active zones in daily remodelled terminals of Drosophila clock neurons. Eur J Neurosci 2024; 59:2665-2685. [PMID: 38414155 DOI: 10.1111/ejn.16294] [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: 06/21/2023] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 02/29/2024]
Abstract
The small ventrolateral neurons (sLNvs) are key components of the central clock in the Drosophila brain. They signal via the neuropeptide pigment-dispersing factor (PDF) to align the molecular clockwork of different central clock neurons and to modulate downstream circuits. The dorsal terminals of the sLNvs undergo daily morphological changes that affect presynaptic sites organised by the active zone protein Bruchpilot (BRP), a homolog of mammalian ELKS proteins. However, the role of these presynaptic sites for PDF release is ill-defined. Here, we combined expansion microscopy with labelling of active zones by endogenously tagged BRP to examine the spatial correlation between PDF-containing dense-core vesicles and BRP-labelled active zones. We found that the number of BRP-labelled puncta in the sLNv terminals was similar while their density differed between Zeitgeber time (ZT) 2 and 14. The relative distance between BRP- and PDF-labelled puncta was increased in the morning, around the reported time of PDF release. Spontaneous dense-core vesicle release profiles of sLNvs in a publicly available ssTEM dataset (FAFB) consistently lacked spatial correlation to BRP-organised active zones. RNAi-mediated downregulation of brp and other active zone proteins expressed by the sLNvs did not affect PDF-dependent locomotor rhythmicity. In contrast, down-regulation of genes encoding proteins of the canonical vesicle release machinery, the dense-core vesicle-related protein CADPS, as well as PDF impaired locomotor rhythmicity. Taken together, our study suggests that PDF release from the sLNvs is independent of BRP-organised active zones, while BRP may be redistributed to active zones in a time-dependent manner.
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Affiliation(s)
- Benedikt Hofbauer
- Biocenter, Theodor-Boveri-Institute, Neurobiology and Genetics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Meet Zandawala
- Biocenter, Theodor-Boveri-Institute, Neurobiology and Genetics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
- Department of Biochemistry and Molecular Biology, University of Nevada Reno, Reno, NV, USA
| | - Nils Reinhard
- Biocenter, Theodor-Boveri-Institute, Neurobiology and Genetics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Dirk Rieger
- Biocenter, Theodor-Boveri-Institute, Neurobiology and Genetics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Christian Werner
- Biocenter, Theodor-Boveri-Institute, Department of Biotechnology and Biophysics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Jan Felix Evers
- Centre for organismal studies COS, Universität Heidelberg, Heidelberg, Germany
- Cairn GmbH, Heidelberg, Germany
| | - Christian Wegener
- Biocenter, Theodor-Boveri-Institute, Neurobiology and Genetics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
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Miyano R, Sakamoto H, Hirose K, Sakaba T. RIM-BP2 regulates Ca 2+ channel abundance and neurotransmitter release at hippocampal mossy fiber terminals. eLife 2024; 12:RP90799. [PMID: 38329474 PMCID: PMC10945523 DOI: 10.7554/elife.90799] [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: 02/09/2024] Open
Abstract
Synaptic vesicles dock and fuse at the presynaptic active zone (AZ), the specialized site for transmitter release. AZ proteins play multiple roles such as recruitment of Ca2+ channels as well as synaptic vesicle docking, priming, and fusion. However, the precise role of each AZ protein type remains unknown. In order to dissect the role of RIM-BP2 at mammalian cortical synapses having low release probability, we applied direct electrophysiological recording and super-resolution imaging to hippocampal mossy fiber terminals of RIM-BP2 knockout (KO) mice. By using direct presynaptic recording, we found the reduced Ca2+ currents. The measurements of excitatory postsynaptic currents (EPSCs) and presynaptic capacitance suggested that the initial release probability was lowered because of the reduced Ca2+ influx and impaired fusion competence in RIM-BP2 KO. Nevertheless, larger Ca2+ influx restored release partially. Consistent with presynaptic recording, STED microscopy suggested less abundance of P/Q-type Ca2+ channels at AZs deficient in RIM-BP2. Our results suggest that the RIM-BP2 regulates both Ca2+ channel abundance and transmitter release at mossy fiber synapses.
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Affiliation(s)
- Rinako Miyano
- Graduate School of Brain Science, Doshisha UniversityKyotoJapan
| | - Hirokazu Sakamoto
- Department of Pharmacology, Graduate School of Medicine, The University of TokyoBunkyo-kuJapan
| | - Kenzo Hirose
- Department of Pharmacology, Graduate School of Medicine, The University of TokyoBunkyo-kuJapan
- International Research Center for Neurointelligence (WPI-IRCN), The University of TokyoBunkyo-kuJapan
| | - Takeshi Sakaba
- Graduate School of Brain Science, Doshisha UniversityKyotoJapan
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3
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Mrestani A, Dannhäuser S, Pauli M, Kollmannsberger P, Hübsch M, Morris L, Langenhan T, Heckmann M, Paul MM. Nanoscaled RIM clustering at presynaptic active zones revealed by endogenous tagging. Life Sci Alliance 2023; 6:e202302021. [PMID: 37696575 PMCID: PMC10494931 DOI: 10.26508/lsa.202302021] [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: 03/02/2023] [Revised: 08/27/2023] [Accepted: 08/28/2023] [Indexed: 09/13/2023] Open
Abstract
Chemical synaptic transmission involves neurotransmitter release from presynaptic active zones (AZs). The AZ protein Rab-3-interacting molecule (RIM) is important for normal Ca2+-triggered release. However, its precise localization within AZs of the glutamatergic neuromuscular junctions of Drosophila melanogaster remains elusive. We used CRISPR/Cas9-assisted genome engineering of the rim locus to incorporate small epitope tags for targeted super-resolution imaging. A V5-tag, derived from simian virus 5, and an HA-tag, derived from human influenza virus, were N-terminally fused to the RIM Zinc finger. Whereas both variants are expressed in co-localization with the core AZ scaffold Bruchpilot, electrophysiological characterization reveals that AP-evoked synaptic release is disturbed in rimV5-Znf but not in rimHA-Znf In addition, rimHA-Znf synapses show intact presynaptic homeostatic potentiation. Combining super-resolution localization microscopy and hierarchical clustering, we detect ∼10 RIMHA-Znf subclusters with ∼13 nm diameter per AZ that are compacted and increased in numbers in presynaptic homeostatic potentiation.
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Affiliation(s)
- Achmed Mrestani
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- Department of Neurology, Leipzig University Medical Center, Leipzig, Germany
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Sven Dannhäuser
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Martin Pauli
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | | | - Martha Hübsch
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Lydia Morris
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Tobias Langenhan
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Manfred Heckmann
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Mila M Paul
- https://ror.org/00fbnyb24 Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- https://ror.org/03pvr2g57 Department of Orthopedic Trauma, Hand, Plastic and Reconstructive Surgery, University Hospital of Würzburg, Würzburg, Germany
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Sigrist SJ, Haucke V. Orchestrating vesicular and nonvesicular membrane dynamics by intrinsically disordered proteins. EMBO Rep 2023; 24:e57758. [PMID: 37680133 PMCID: PMC10626433 DOI: 10.15252/embr.202357758] [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: 07/05/2023] [Revised: 08/22/2023] [Accepted: 08/24/2023] [Indexed: 09/09/2023] Open
Abstract
Compartmentalization by membranes is a common feature of eukaryotic cells and serves to spatiotemporally confine biochemical reactions to control physiology. Membrane-bound organelles such as the endoplasmic reticulum (ER), the Golgi complex, endosomes and lysosomes, and the plasma membrane, continuously exchange material via vesicular carriers. In addition to vesicular trafficking entailing budding, fission, and fusion processes, organelles can form membrane contact sites (MCSs) that enable the nonvesicular exchange of lipids, ions, and metabolites, or the secretion of neurotransmitters via subsequent membrane fusion. Recent data suggest that biomolecule and information transfer via vesicular carriers and via MCSs share common organizational principles and are often mediated by proteins with intrinsically disordered regions (IDRs). Intrinsically disordered proteins (IDPs) can assemble via low-affinity, multivalent interactions to facilitate membrane tethering, deformation, fission, or fusion. Here, we review our current understanding of how IDPs drive the formation of multivalent protein assemblies and protein condensates to orchestrate vesicular and nonvesicular transport with a special focus on presynaptic neurotransmission. We further discuss how dysfunction of IDPs causes disease and outline perspectives for future research.
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Affiliation(s)
- Stephan J Sigrist
- Department of Biology, Chemistry, PharmacyFreie Universität BerlinBerlinGermany
| | - Volker Haucke
- Department of Biology, Chemistry, PharmacyFreie Universität BerlinBerlinGermany
- Department of Molecular Pharmacology and Cell BiologyLeibniz Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
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5
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Krout M, Oh KH, Xiong A, Frankel EB, Kurshan PT, Kim H, Richmond JE. C. elegans Clarinet/CLA-1 recruits RIMB-1/RIM-binding protein and UNC-13 to orchestrate presynaptic neurotransmitter release. Proc Natl Acad Sci U S A 2023; 120:e2220856120. [PMID: 37186867 PMCID: PMC10214197 DOI: 10.1073/pnas.2220856120] [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: 12/07/2022] [Accepted: 04/05/2023] [Indexed: 05/17/2023] Open
Abstract
Synaptic transmission requires the coordinated activity of multiple synaptic proteins that are localized at the active zone (AZ). We previously identified a Caenorhabditis elegans protein named Clarinet (CLA-1) based on homology to the AZ proteins Piccolo, Rab3-interactingmolecule (RIM)/UNC-10 and Fife. At the neuromuscular junction (NMJ), cla-1 null mutants exhibit release defects that are greatly exacerbated in cla-1;unc-10 double mutants. To gain insights into the coordinated roles of CLA-1 and UNC-10, we examined the relative contributions of each to the function and organization of the AZ. Using a combination of electrophysiology, electron microscopy, and quantitative fluorescence imaging we explored the functional relationship of CLA-1 to other key AZ proteins including: RIM1, Cav2.1 channels, RIM1-binding protein, and Munc13 (C. elegans UNC-10, UNC-2, RIMB-1 and UNC-13, respectively). Our analyses show that CLA-1 acts in concert with UNC-10 to regulate UNC-2 calcium channel levels at the synapse via recruitment of RIMB-1. In addition, CLA-1 exerts a RIMB-1-independent role in the localization of the priming factor UNC-13. Thus C. elegans CLA-1/UNC-10 exhibit combinatorial effects that have overlapping design principles with other model organisms: RIM/RBP and RIM/ELKS in mouse and Fife/RIM and BRP/RBP in Drosophila. These data support a semiconserved arrangement of AZ scaffolding proteins that are necessary for the localization and activation of the fusion machinery within nanodomains for precise coupling to Ca2+ channels.
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Affiliation(s)
- Mia Krout
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL60607
| | - Kelly H. Oh
- Department of Cell Biology and Anatomy, Center for Cancer Cell Biology, Immunology, and Infection, Chicago Medical School, School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL60064
| | - Ame Xiong
- Department of Cell Biology and Anatomy, Center for Cancer Cell Biology, Immunology, and Infection, Chicago Medical School, School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, IL60064
| | - Elisa B. Frankel
- Department of Genetics, Albert Einstein College of Medicine, New York, NY10461
| | - Peri T. Kurshan
- Department of Genetics, Albert Einstein College of Medicine, New York, NY10461
| | - Hongkyun Kim
- Department of Genetics, Albert Einstein College of Medicine, New York, NY10461
| | - Janet E. Richmond
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL60607
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6
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Lefebvre-Omar C, Liu E, Dalle C, d'Incamps BL, Bigou S, Daube C, Karpf L, Davenne M, Robil N, Jost Mousseau C, Blanchard S, Tournaire G, Nicaise C, Salachas F, Lacomblez L, Seilhean D, Lobsiger CS, Millecamps S, Boillée S, Bohl D. Neurofilament accumulations in amyotrophic lateral sclerosis patients' motor neurons impair axonal initial segment integrity. Cell Mol Life Sci 2023; 80:150. [PMID: 37184603 DOI: 10.1007/s00018-023-04797-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 04/24/2023] [Accepted: 05/03/2023] [Indexed: 05/16/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is the most common motor neuron (MN) disease in adults with no curative treatment. Neurofilament (NF) level in patient' fluids have recently emerged as the prime biomarker of ALS disease progression, while NF accumulation in MNs of patients is the oldest and one of the best pathological hallmarks. However, the way NF accumulations could lead to MN degeneration remains unknown. To assess NF accumulations and study the impact on MNs, we compared MNs derived from induced pluripotent stem cells (iPSC) of patients carrying mutations in C9orf72, SOD1 and TARDBP genes, the three main ALS genetic causes. We show that in all mutant MNs, light NF (NF-L) chains rapidly accumulate in MN soma, while the phosphorylated heavy/medium NF (pNF-M/H) chains pile up in axonal proximal regions of only C9orf72 and SOD1 MNs. Excitability abnormalities were also only observed in these latter MNs. We demonstrate that the integrity of the MN axonal initial segment (AIS), the region of action potential initiation and responsible for maintaining axonal integrity, is impaired in the presence of pNF-M/H accumulations in C9orf72 and SOD1 MNs. We establish a strong correlation between these pNF-M/H accumulations, an AIS distal shift, increased axonal calibers and modified repartition of sodium channels. The results expand our understanding of how NF accumulation could dysregulate components of the axonal cytoskeleton and disrupt MN homeostasis. With recent cumulative evidence that AIS alterations are implicated in different brain diseases, preserving AIS integrity could have important therapeutic implications for ALS.
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Affiliation(s)
- Cynthia Lefebvre-Omar
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Elise Liu
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Carine Dalle
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Boris Lamotte d'Incamps
- Université Paris-Cité, CNRS, Saints-Pères Paris Institute for the Neurosciences, Paris, France
| | - Stéphanie Bigou
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Clément Daube
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Léa Karpf
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Marc Davenne
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | | | - Coline Jost Mousseau
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Stéphane Blanchard
- Institut Pasteur, INSERM U1115, Unité Biothérapies pour les Maladies Neurodégénératives, Paris, France
| | - Guillaume Tournaire
- Institut Pasteur, INSERM U1115, Unité Biothérapies pour les Maladies Neurodégénératives, Paris, France
| | | | - François Salachas
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
- Département de Neurologie, Assistance Publique Hôpitaux de Paris (APHP), Centre de Référence SLA Ile de France, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Lucette Lacomblez
- Département de Neurologie, Assistance Publique Hôpitaux de Paris (APHP), Centre de Référence SLA Ile de France, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Danielle Seilhean
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
- Département de Neuropathologie, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Christian S Lobsiger
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Stéphanie Millecamps
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Séverine Boillée
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Delphine Bohl
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute-ICM, Inserm, CNRS, AP-HP, Hôpital de la Pitié-Salpêtrière, Paris, France.
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7
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Synaptic Development in Diverse Olfactory Neuron Classes Uses Distinct Temporal and Activity-Related Programs. J Neurosci 2023; 43:28-55. [PMID: 36446587 PMCID: PMC9838713 DOI: 10.1523/jneurosci.0884-22.2022] [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: 05/12/2022] [Revised: 10/18/2022] [Accepted: 11/02/2022] [Indexed: 12/03/2022] Open
Abstract
Developing neurons must meet core molecular, cellular, and temporal requirements to ensure the correct formation of synapses, resulting in functional circuits. However, because of the vast diversity in neuronal class and function, it is unclear whether or not all neurons use the same organizational mechanisms to form synaptic connections and achieve functional and morphologic maturation. Moreover, it remains unknown whether neurons united in a common goal and comprising the same sensory circuit develop on similar timescales and use identical molecular approaches to ensure the formation of the correct number of synapses. To begin to answer these questions, we took advantage of the Drosophila antennal lobe (AL), a model olfactory circuit with remarkable genetic access and synapse-level resolution. Using tissue-specific genetic labeling of active zones, we performed a quantitative analysis of synapse formation in multiple classes of neurons of both sexes throughout development and adulthood. We found that olfactory receptor neurons (ORNs), projection neurons (PNs), and local interneurons (LNs) each have unique time courses of synaptic development, addition, and refinement, demonstrating that each class follows a distinct developmental program. This raised the possibility that these classes may also have distinct molecular requirements for synapse formation. We genetically altered neuronal activity in each neuronal subtype and observed differing effects on synapse number based on the neuronal class examined. Silencing neuronal activity in ORNs, PNs, and LNs impaired synaptic development but only in ORNs did enhancing neuronal activity influence synapse formation. ORNs and LNs demonstrated similar impairment of synaptic development with enhanced activity of a master kinase, GSK-3β, suggesting that neuronal activity and GSK-3β kinase activity function in a common pathway. ORNs also, however, demonstrated impaired synaptic development with GSK-3β loss-of-function, suggesting additional activity-independent roles in development. Ultimately, our results suggest that the requirements for synaptic development are not uniform across all neuronal classes with considerable diversity existing in both their developmental time frames and molecular requirements. These findings provide novel insights into the mechanisms of synaptic development and lay the foundation for future work determining their underlying etiologies.SIGNIFICANCE STATEMENT Distinct olfactory neuron classes in Drosophila develop a mature synaptic complement over unique timelines and using distinct activity-dependent and molecular programs, despite having the same generalized goal of olfactory sensation.
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Dannhäuser S, Mrestani A, Gundelach F, Pauli M, Komma F, Kollmannsberger P, Sauer M, Heckmann M, Paul MM. Endogenous tagging of Unc-13 reveals nanoscale reorganization at active zones during presynaptic homeostatic potentiation. Front Cell Neurosci 2022; 16:1074304. [PMID: 36589286 PMCID: PMC9797049 DOI: 10.3389/fncel.2022.1074304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 11/23/2022] [Indexed: 12/15/2022] Open
Abstract
Introduction Neurotransmitter release at presynaptic active zones (AZs) requires concerted protein interactions within a dense 3D nano-hemisphere. Among the complex protein meshwork the (M)unc-13 family member Unc-13 of Drosophila melanogaster is essential for docking of synaptic vesicles and transmitter release. Methods We employ minos-mediated integration cassette (MiMIC)-based gene editing using GFSTF (EGFP-FlAsH-StrepII-TEV-3xFlag) to endogenously tag all annotated Drosophila Unc-13 isoforms enabling visualization of endogenous Unc-13 expression within the central and peripheral nervous system. Results and discussion Electrophysiological characterization using two-electrode voltage clamp (TEVC) reveals that evoked and spontaneous synaptic transmission remain unaffected in unc-13 GFSTF 3rd instar larvae and acute presynaptic homeostatic potentiation (PHP) can be induced at control levels. Furthermore, multi-color structured-illumination shows precise co-localization of Unc-13GFSTF, Bruchpilot, and GluRIIA-receptor subunits within the synaptic mesoscale. Localization microscopy in combination with HDBSCAN algorithms detect Unc-13GFSTF subclusters that move toward the AZ center during PHP with unaltered Unc-13GFSTF protein levels.
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Affiliation(s)
- Sven Dannhäuser
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Achmed Mrestani
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- Department of Neurology, Leipzig University Medical Center, Leipzig, Germany
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Florian Gundelach
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- Center of Mental Health, Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Würzburg, Würzburg, Germany
| | - Martin Pauli
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Fabian Komma
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Philip Kollmannsberger
- Center for Computational and Theoretical Biology, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Manfred Heckmann
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Mila M Paul
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- Department of Orthopedic Trauma, Hand, Plastic and Reconstructive Surgery, University Hospital of Würzburg, Würzburg, Germany
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9
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Turrel O, Ramesh N, Escher MJF, Pooryasin A, Sigrist SJ. Transient active zone remodeling in the Drosophila mushroom body supports memory. Curr Biol 2022; 32:4900-4913.e4. [PMID: 36327980 DOI: 10.1016/j.cub.2022.10.017] [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: 12/16/2021] [Revised: 08/15/2022] [Accepted: 10/06/2022] [Indexed: 11/22/2022]
Abstract
Elucidating how the distinct components of synaptic plasticity dynamically orchestrate the distinct stages of memory acquisition and maintenance within neuronal networks remains a major challenge. Specifically, plasticity processes tuning the functional and also structural state of presynaptic active zone (AZ) release sites are widely observed in vertebrates and invertebrates, but their behavioral relevance remains mostly unclear. We here provide evidence that a transient upregulation of presynaptic AZ release site proteins supports aversive olfactory mid-term memory in the Drosophila mushroom body (MB). Upon paired aversive olfactory conditioning, AZ protein levels (ELKS-family BRP/(m)unc13-family release factor Unc13A) increased for a few hours with MB-lobe-specific dynamics. Kenyon cell (KC, intrinsic MB neurons)-specific knockdown (KD) of BRP did not affect aversive olfactory short-term memory (STM) but strongly suppressed aversive mid-term memory (MTM). Different proteins crucial for the transport of AZ biosynthetic precursors (transport adaptor Aplip1/Jip-1; kinesin motor IMAC/Unc104; small GTPase Arl8) were also specifically required for the formation of aversive olfactory MTM. Consistent with the merely transitory increase of AZ proteins, BRP KD did not interfere with the formation of aversive olfactory long-term memory (LTM; i.e., 1 day). Our data suggest that the remodeling of presynaptic AZ refines the MB circuitry after paired aversive conditioning, over a time window of a few hours, to display aversive olfactory memories.
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Affiliation(s)
- Oriane Turrel
- Institute for Biology/Genetics, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany
| | - Niraja Ramesh
- Institute for Biology/Genetics, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany
| | - Marc J F Escher
- Institute for Biology/Genetics, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany
| | - Atefeh Pooryasin
- Institute for Biology/Genetics, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany
| | - Stephan J Sigrist
- Institute for Biology/Genetics, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany; NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Charitéplatz 1, 10117 Berlin, Germany.
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10
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Sun SY, Li XW, Cao R, Zhao Y, Sheng N, Tang AH. Correlative Assembly of Subsynaptic Nanoscale Organizations During Development. Front Synaptic Neurosci 2022; 14:748184. [PMID: 35685244 PMCID: PMC9171000 DOI: 10.3389/fnsyn.2022.748184] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 03/11/2022] [Indexed: 11/17/2022] Open
Abstract
Nanoscale organization of presynaptic proteins determines the sites of transmitter release, and its alignment with assemblies of postsynaptic receptors through nanocolumns is suggested to optimize the efficiency of synaptic transmission. However, it remains unknown how these nano-organizations are formed during development. In this study, we used super-resolution stochastic optical reconstruction microscopy (STORM) imaging technique to systematically analyze the evolvement of subsynaptic organization of three key synaptic proteins, namely, RIM1/2, GluA1, and PSD-95, during synapse maturation in cultured hippocampal neurons. We found that volumes of synaptic clusters and their subsynaptic heterogeneity increase as synapses get matured. Synapse sizes of presynaptic and postsynaptic compartments correlated well at all stages, while only more mature synapses demonstrated a significant correlation between presynaptic and postsynaptic nano-organizations. After a long incubation with an inhibitor of action potentials or AMPA receptors, both presynaptic and postsynaptic compartments showed increased synaptic cluster volume and subsynaptic heterogeneity; however, the trans-synaptic alignment was intact. Together, our results characterize the evolvement of subsynaptic protein architectures during development and demonstrate that the nanocolumn is organized more likely by an intrinsic mechanism and independent of synaptic activities.
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Affiliation(s)
- Shi-Yan Sun
- Chinese Academy of Sciences (CAS) Key Laboratory of Brain Function and Disease, 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, Hefei, China
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, China
| | - Xiao-Wei Li
- Chinese Academy of Sciences (CAS) Key Laboratory of Brain Function and Disease, 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, Hefei, China
| | - Ran Cao
- Chinese Academy of Sciences (CAS) Key Laboratory of Brain Function and Disease, 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, Hefei, China
| | - Yang Zhao
- Chinese Academy of Sciences (CAS) Key Laboratory of Brain Function and Disease, 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, Hefei, China
- State Key Laboratory of Genetic Resources and Evolution in Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Nengyin Sheng
- State Key Laboratory of Genetic Resources and Evolution in Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- Nengyin Sheng
| | - Ai-Hui Tang
- Chinese Academy of Sciences (CAS) Key Laboratory of Brain Function and Disease, 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, Hefei, China
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, China
- *Correspondence: Ai-Hui Tang
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11
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Paul MM, Dannhäuser S, Morris L, Mrestani A, Hübsch M, Gehring J, Hatzopoulos GN, Pauli M, Auger GM, Bornschein G, Scholz N, Ljaschenko D, Müller M, Sauer M, Schmidt H, Kittel RJ, DiAntonio A, Vakonakis I, Heckmann M, Langenhan T. The human cognition-enhancing CORD7 mutation increases active zone number and synaptic release. Brain 2022; 145:3787-3802. [DOI: 10.1093/brain/awac011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/29/2021] [Accepted: 12/16/2021] [Indexed: 11/13/2022] Open
Abstract
Abstract
Humans carrying the CORD7 (cone-rod dystrophy 7) mutation possess increased verbal IQ and working memory. This autosomal dominant syndrome is caused by the single-amino acid R844H exchange (human numbering) located in the 310 helix of the C2A domain of RIMS1/RIM1 (Rab3-interacting molecule 1). RIM is an evolutionarily conserved multi-domain protein and essential component of presynaptic active zones, which is centrally involved in fast, Ca2+-triggered neurotransmitter release. How the CORD7 mutation affects synaptic function has remained unclear thus far. Here, we established Drosophila melanogaster as a disease model for clarifying the effects of the CORD7 mutation on RIM function and synaptic vesicle release.
To this end, using protein expression and X-ray crystallography, we solved the molecular structure of the Drosophila C2A domain at 1.92 Å resolution and by comparison to its mammalian homolog ascertained that the location of the CORD7 mutation is structurally conserved in fly RIM. Further, CRISPR/Cas9-assisted genomic engineering was employed for the generation of rim alleles encoding the R915H CORD7 exchange or R915E,R916E substitutions (fly numbering) to effect local charge reversal at the 310 helix. Through electrophysiological characterization by two-electrode voltage clamp and focal recordings we determined that the CORD7 mutation exerts a semi-dominant rather than a dominant effect on synaptic transmission resulting in faster, more efficient synaptic release and increased size of the readily releasable pool but decreased sensitivity for the fast calcium chelator BAPTA. In addition, the rim CORD7 allele increased the number of presynaptic active zones but left their nanoscopic organization unperturbed as revealed by super-resolution microscopy of the presynaptic scaffold protein Bruchpilot/ELKS/CAST.
We conclude that the CORD7 mutation leads to tighter release coupling, an increased readily releasable pool size and more release sites thereby promoting more efficient synaptic transmitter release. These results strongly suggest that similar mechanisms may underlie the CORD7 disease phenotype in patients and that enhanced synaptic transmission may contribute to their increased cognitive abilities.
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Affiliation(s)
- Mila M. Paul
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany
- Department of Orthopaedic Trauma, Hand, Plastic and Reconstructive Surgery, University Hospital of Würzburg, 97080 Würzburg, Germany
| | - Sven Dannhäuser
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany
| | - Lydia Morris
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103 Leipzig, Germany
| | - Achmed Mrestani
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103 Leipzig, Germany
- Department of Neurology, Leipzig University Medical Center, 04103 Leipzig, Germany
| | - Martha Hübsch
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany
| | - Jennifer Gehring
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany
| | | | - Martin Pauli
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany
| | - Genevieve M. Auger
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103 Leipzig, Germany
| | - Grit Bornschein
- Carl Ludwig Institute of Physiology, Medical Faculty, Leipzig University, 04103 Leipzig, Germany
| | - Nicole Scholz
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103 Leipzig, Germany
| | - Dmitrij Ljaschenko
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103 Leipzig, Germany
| | - Martin Müller
- Department of Molecular Life Sciences, University of Zürich, 8057 Zürich, Switzerland
| | - Markus Sauer
- Department of Biotechnology and Biophysics, University of Würzburg, 97074 Würzburg, Germany
| | - Hartmut Schmidt
- Carl Ludwig Institute of Physiology, Medical Faculty, Leipzig University, 04103 Leipzig, Germany
| | - Robert J. Kittel
- Carl Ludwig Institute of Physiology, Medical Faculty, Leipzig University, 04103 Leipzig, Germany
- Department of Animal Physiology, Institute of Biology, Leipzig University, 04103 Leipzig, Germany
| | - Aaron DiAntonio
- Department of Molecular Biology and Pharmacology, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | | | - Manfred Heckmann
- Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany
| | - Tobias Langenhan
- Division of General Biochemistry, Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, 04103 Leipzig, Germany
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12
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Abstract
Fluorescence imaging techniques play a pivotal role in our understanding of the nervous system. The emergence of various super-resolution microscopy methods and specialized fluorescent probes enables direct insight into neuronal structure and protein arrangements in cellular subcompartments with so far unmatched resolution. Super-resolving visualization techniques in neurons unveil a novel understanding of cytoskeletal composition, distribution, motility, and signaling of membrane proteins, subsynaptic structure and function, and neuron-glia interaction. Well-defined molecular targets in autoimmune and neurodegenerative disease models provide excellent starting points for in-depth investigation of disease pathophysiology using novel and innovative imaging methodology. Application of super-resolution microscopy in human brain samples and for testing clinical biomarkers is still in its infancy but opens new opportunities for translational research in neurology and neuroscience. In this review, we describe how super-resolving microscopy has improved our understanding of neuronal and brain function and dysfunction in the last two decades.
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Affiliation(s)
- Christian Werner
- Department of Biotechnology & Biophysics, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Markus Sauer
- Department of Biotechnology & Biophysics, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Christian Geis
- Section Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747 Jena, Germany
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13
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Oh KH, Krout MD, Richmond JE, Kim H. UNC-2 CaV2 Channel Localization at Presynaptic Active Zones Depends on UNC-10/RIM and SYD-2/Liprin-α in Caenorhabditis elegans. J Neurosci 2021; 41:4782-4794. [PMID: 33975919 PMCID: PMC8260173 DOI: 10.1523/jneurosci.0076-21.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/07/2021] [Accepted: 04/29/2021] [Indexed: 12/20/2022] Open
Abstract
Presynaptic active zone proteins couple calcium influx with synaptic vesicle exocytosis. However, the control of presynaptic calcium channel localization by active zone proteins is not completely understood. In a Caenorhabditis elegans (C. elegans) forward genetic screen, we find that UNC-10/RIM (Rab3-interacting molecule) and SYD-2/Liprin-α regulate presynaptic localization of UNC-2, the CaV2 channel ortholog. We further quantitatively analyzed live animals using endogenously GFP-tagged UNC-2 and active zone components. Consistent with the interaction between RIM and CaV2 in mammals, the intensity and number of UNC-2 channel puncta at presynaptic terminals were greatly reduced in unc-10 mutant animals. To understand how SYD-2 regulates presynaptic UNC-2 channel localization, we analyzed presynaptic localization of endogenous SYD-2, UNC-10, RIMB-1/RIM-BP (RIM binding protein), and ELKS-1. Our analysis revealed that although SYD-2 is the most critical for active zone assembly, loss of SYD-2 function does not completely abolish presynaptic localization of UNC-10, RIMB-1, and ELKS-1, suggesting an existence of SYD-2-independent active zone assembly. UNC-2 localization analysis in double and triple mutants of active zone components show that SYD-2 promotes UNC-2 localization by partially controlling UNC-10 localization, and ELKS-1 and RIMB-1 also contribute to UNC-2 channel localization. In addition, we find that core active zone proteins are unequal in their abundance. Although the abundance of UNC-10 at the active zone is comparable to UNC-2, SYD-2 and ELKS-1 are twice more and RIMB-1 four times more abundant than UNC-2. Together our data show that UNC-10, SYD-2, RIMB-1, and ELKS-1 control presynaptic UNC-2 channel localization in redundant yet distinct manners.SIGNIFICANCE STATEMENT Precise control of neurotransmission is dependent on the tight coupling of the calcium influx through voltage-gated calcium channels (VGCCs) to the exocytosis machinery at the presynaptic active zones. However, how these VGCCs are tethered to the active zone is incompletely understood. To understand the mechanism of presynaptic VGCC localization, we performed a C. elegans forward genetic screen and quantitatively analyzed endogenous active zones and presynaptic VGCCs. In addition to RIM, our study finds that SYD-2/Liprin-α is critical for presynaptic localization of VGCCs. Yet, the loss of SYD-2, a core active zone scaffolding protein, does not completely abolish the presynaptic localization of the VGCC, showing that the active zone is a resilient structure assembled by redundant mechanisms.
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Affiliation(s)
- Kelly H Oh
- Center for Cancer Cell Biology, Immunology, and Infection, Department of Cell Biology and Anatomy, Chicago Medical School, School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois 60064
| | - Mia D Krout
- Department of Biological Science, University of Illinois at Chicago, Chicago, Illinois 60607
| | - Janet E Richmond
- Department of Biological Science, University of Illinois at Chicago, Chicago, Illinois 60607
| | - Hongkyun Kim
- Center for Cancer Cell Biology, Immunology, and Infection, Department of Cell Biology and Anatomy, Chicago Medical School, School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois 60064
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14
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Krinner S, Predoehl F, Burfeind D, Vogl C, Moser T. RIM-Binding Proteins Are Required for Normal Sound-Encoding at Afferent Inner Hair Cell Synapses. Front Mol Neurosci 2021; 14:651935. [PMID: 33867935 PMCID: PMC8044855 DOI: 10.3389/fnmol.2021.651935] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/22/2021] [Indexed: 11/19/2022] Open
Abstract
The afferent synapses between inner hair cells (IHC) and spiral ganglion neurons are specialized to faithfully encode sound with sub-millisecond precision over prolonged periods of time. Here, we studied the role of Rab3 interacting molecule-binding proteins (RIM-BP) 1 and 2 – multidomain proteins of the active zone known to directly interact with RIMs, Bassoon and CaV1.3 – in IHC presynaptic function and hearing. Recordings of auditory brainstem responses and otoacoustic emissions revealed that genetic disruption of RIM-BPs 1 and 2 in mice (RIM-BP1/2–/–) causes a synaptopathic hearing impairment exceeding that found in mice lacking RIM-BP2 (RIM-BP2–/–). Patch-clamp recordings from RIM-BP1/2–/– IHCs indicated a subtle impairment of exocytosis from the readily releasable pool of synaptic vesicles that had not been observed in RIM-BP2–/– IHCs. In contrast, the reduction of Ca2+-influx and sustained exocytosis was similar to that in RIMBP2–/– IHCs. We conclude that both RIM-BPs are required for normal sound encoding at the IHC synapse, whereby RIM-BP2 seems to take the leading role.
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Affiliation(s)
- Stefanie Krinner
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Collaborative Research Center 1286, University of Göttingen, Göttingen, Germany.,Auditory Neuroscience Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Friederike Predoehl
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Dinah Burfeind
- Presynaptogenesis and Intracellular Transport in Hair Cells Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Christian Vogl
- Auditory Neuroscience Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Presynaptogenesis and Intracellular Transport in Hair Cells Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Tobias Moser
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany.,Collaborative Research Center 1286, University of Göttingen, Göttingen, Germany.,Auditory Neuroscience Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Multiscale Bioimaging Cluster of Excellence, University of Göttingen, Göttingen, Germany
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15
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Minehart JA, Speer CM. A Picture Worth a Thousand Molecules-Integrative Technologies for Mapping Subcellular Molecular Organization and Plasticity in Developing Circuits. Front Synaptic Neurosci 2021; 12:615059. [PMID: 33469427 PMCID: PMC7813761 DOI: 10.3389/fnsyn.2020.615059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 12/07/2020] [Indexed: 12/23/2022] Open
Abstract
A key challenge in developmental neuroscience is identifying the local regulatory mechanisms that control neurite and synaptic refinement over large brain volumes. Innovative molecular techniques and high-resolution imaging tools are beginning to reshape our view of how local protein translation in subcellular compartments drives axonal, dendritic, and synaptic development and plasticity. Here we review recent progress in three areas of neurite and synaptic study in situ-compartment-specific transcriptomics/translatomics, targeted proteomics, and super-resolution imaging analysis of synaptic organization and development. We discuss synergies between sequencing and imaging techniques for the discovery and validation of local molecular signaling mechanisms regulating synaptic development, plasticity, and maintenance in circuits.
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Affiliation(s)
| | - Colenso M. Speer
- Department of Biology, University of Maryland, College Park, MD, United States
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