1
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Harris KM, Kuwajima M, Flores JC, Zito K. Synapse-specific structural plasticity that protects and refines local circuits during LTP and LTD. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230224. [PMID: 38853547 DOI: 10.1098/rstb.2023.0224] [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: 10/17/2023] [Accepted: 01/05/2024] [Indexed: 06/11/2024] Open
Abstract
Synapses form trillions of connections in the brain. Long-term potentiation (LTP) and long-term depression (LTD) are cellular mechanisms vital for learning that modify the strength and structure of synapses. Three-dimensional reconstruction from serial section electron microscopy reveals three distinct pre- to post-synaptic arrangements: strong active zones (AZs) with tightly docked vesicles, weak AZs with loose or non-docked vesicles, and nascent zones (NZs) with a postsynaptic density but no presynaptic vesicles. Importantly, LTP can be temporarily saturated preventing further increases in synaptic strength. At the onset of LTP, vesicles are recruited to NZs, converting them to AZs. During recovery of LTP from saturation (1-4 h), new NZs form, especially on spines where AZs are most enlarged by LTP. Sentinel spines contain smooth endoplasmic reticulum (SER), have the largest synapses and form clusters with smaller spines lacking SER after LTP recovers. We propose a model whereby NZ plasticity provides synapse-specific AZ expansion during LTP and loss of weak AZs that drive synapse shrinkage during LTD. Spine clusters become functionally engaged during LTP or disassembled during LTD. Saturation of LTP or LTD probably acts to protect recently formed memories from ongoing plasticity and may account for the advantage of spaced over massed learning. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Kristen M Harris
- Department of Neuroscience and Center for Learning and Memory, The University of Texas at Austin , Austin, TX 78712, USA
| | - Masaaki Kuwajima
- Department of Neuroscience and Center for Learning and Memory, The University of Texas at Austin , Austin, TX 78712, USA
| | - Juan C Flores
- Center for Neuroscience, University of California , Davis, CA 95618, USA
| | - Karen Zito
- Center for Neuroscience, University of California , Davis, CA 95618, USA
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2
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Caya-Bissonnette L, Béïque JC. Half a century legacy of long-term potentiation. Curr Biol 2024; 34:R640-R662. [PMID: 38981433 DOI: 10.1016/j.cub.2024.05.008] [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
In 1973, two papers from Bliss and Lømo and from Bliss and Gardner-Medwin reported that high-frequency synaptic stimulation in the dentate gyrus of rabbits resulted in a long-lasting increase in synaptic strength. This form of synaptic plasticity, commonly referred to as long-term potentiation (LTP), was immediately considered as an attractive mechanism accounting for the ability of the brain to store information. In this historical piece looking back over the past 50 years, we discuss how these two landmark contributions directly motivated a colossal research effort and detail some of the resulting milestones that have shaped our evolving understanding of the molecular and cellular underpinnings of LTP. We highlight the main features of LTP, cover key experiments that defined its induction and expression mechanisms, and outline the evidence supporting a potential role of LTP in learning and memory. We also briefly explore some ramifications of LTP on network stability, consider current limitations of LTP as a model of associative memory, and entertain future research orientations.
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Affiliation(s)
- Léa Caya-Bissonnette
- Graduate Program in Neuroscience, University of Ottawa, 451 ch. Smyth Road (3501N), Ottawa, ON K1H 8M5, Canada; Brain and Mind Research Institute's Centre for Neural Dynamics and Artificial Intelligence, 451 ch. Smyth Road (3501N), Ottawa, ON K1H 8M5, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, 451 ch. Smyth Road (3501N), Ottawa, ON K1H 8M5, Canada
| | - Jean-Claude Béïque
- Brain and Mind Research Institute's Centre for Neural Dynamics and Artificial Intelligence, 451 ch. Smyth Road (3501N), Ottawa, ON K1H 8M5, Canada; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, 451 ch. Smyth Road (3501N), Ottawa, ON K1H 8M5, Canada.
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3
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Lee CT, Bell M, Bonilla-Quintana M, Rangamani P. Biophysical Modeling of Synaptic Plasticity. Annu Rev Biophys 2024; 53:397-426. [PMID: 38382115 DOI: 10.1146/annurev-biophys-072123-124954] [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] [Indexed: 02/23/2024]
Abstract
Dendritic spines are small, bulbous compartments that function as postsynaptic sites and undergo intense biochemical and biophysical activity. The role of the myriad signaling pathways that are implicated in synaptic plasticity is well studied. A recent abundance of quantitative experimental data has made the events associated with synaptic plasticity amenable to quantitative biophysical modeling. Spines are also fascinating biophysical computational units because spine geometry, signal transduction, and mechanics work in a complex feedback loop to tune synaptic plasticity. In this sense, ideas from modeling cell motility can inspire us to develop multiscale approaches for predictive modeling of synaptic plasticity. In this article, we review the key steps in postsynaptic plasticity with a specific focus on the impact of spine geometry on signaling, cytoskeleton rearrangement, and membrane mechanics. We summarize the main experimental observations and highlight how theory and computation can aid our understanding of these complex processes.
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Affiliation(s)
- Christopher T Lee
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA;
| | - Miriam Bell
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA;
| | - Mayte Bonilla-Quintana
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA;
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA;
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4
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Bressloff PC. Asymptotic analysis of particle cluster formation in the presence of anchoring sites. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2024; 47:30. [PMID: 38720027 PMCID: PMC11078859 DOI: 10.1140/epje/s10189-024-00425-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 04/15/2024] [Indexed: 05/12/2024]
Abstract
The aggregation or clustering of proteins and other macromolecules plays an important role in the formation of large-scale molecular assemblies within cell membranes. Examples of such assemblies include lipid rafts, and postsynaptic domains (PSDs) at excitatory and inhibitory synapses in neurons. PSDs are rich in scaffolding proteins that can transiently trap transmembrane neurotransmitter receptors, thus localizing them at specific spatial positions. Hence, PSDs play a key role in determining the strength of synaptic connections and their regulation during learning and memory. Recently, a two-dimensional (2D) diffusion-mediated aggregation model of PSD formation has been developed in which the spatial locations of the clusters are determined by a set of fixed anchoring sites. The system is kept out of equilibrium by the recycling of particles between the cell membrane and interior. This results in a stationary distribution consisting of multiple clusters, whose average size can be determined using an effective mean-field description of the particle concentration around each anchored cluster. In this paper, we derive corrections to the mean-field approximation by applying the theory of diffusion in singularly perturbed domains. The latter is a powerful analytical method for solving two-dimensional (2D) and three-dimensional (3D) diffusion problems in domains where small holes or perforations have been removed from the interior. Applications range from modeling intracellular diffusion, where interior holes could represent subcellular structures such as organelles or biological condensates, to tracking the spread of chemical pollutants or heat from localized sources. In this paper, we take the bounded domain to be the cell membrane and the holes to represent anchored clusters. The analysis proceeds by partitioning the membrane into a set of inner regions around each cluster, and an outer region where mean-field interactions occur. Asymptotically matching the inner and outer stationary solutions generates an asymptotic expansion of the particle concentration, which includes higher-order corrections to mean-field theory that depend on the positions of the clusters and the boundary of the domain. Motivated by a recent study of light-activated protein oligomerization in cells, we also develop the analogous theory for cluster formation in a three-dimensional (3D) domain. The details of the asymptotic analysis differ from the 2D case due to the contrasting singularity structure of 2D and 3D Green's functions.
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Affiliation(s)
- Paul C Bressloff
- Department of Mathematics, Imperial College London, London, SW7 2AZ, UK.
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5
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Zinchenko VP, Dolgacheva LP, Tuleukhanov ST. Calcium-permeable AMPA and kainate receptors of GABAergic neurons. Biophys Rev 2024; 16:165-171. [PMID: 38737208 PMCID: PMC11078900 DOI: 10.1007/s12551-024-01184-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 03/16/2024] [Indexed: 05/14/2024] Open
Abstract
This Commentary presents a brief discussion of the action of glutamate calcium permeable receptors present with neurons on the release of the neurotransmitter gamma-aminobutyric acid (GABA). In particular, Glutamate sensitive Kainic Acid Receptors (KARs) and α-Amino-3-hydroxy-5-Methyl-4-isoxazole Propionic Acid Receptor (AMPARs) are Na+ channels that typically cause neuronal cells to depolarize and release GABA. Some of these receptors are also permeable to Ca2+ and are hence involved in the calcium-dependent release of GABA neurotransmitters. Calcium-permeable kainate and AMPA receptors (CP-KARs and CP-AMPARs) are predominantly located in GABAergic neurons in the mature brain and their primary role is to regulate GABA release. AMPARs which do not contain the GluA2 subunit are mainly localized in the postsynaptic membrane. CP-KAR receptors are located mainly in the presynapse. GABAergic neurons expressing CP-KARs and CP-AMPARs respond to excitation earlier and faster, suppressing hyperexcitation of other neurons by the advanced GABA release due to an early rapid [Ca2+]i increase. CP-AMPARs have demonstrated a more pronounced impact on plasticity compared to NMDARs because of their capacity to elevate intracellular Ca2+ levels independently of voltage. GABAergic neurons that express CP-AMPARs contribute to the disinhibition of glutamatergic neurons by suppressing GABAergic neurons that express CP-KARs. Hence, the presence of glutamate CP-KARs and CP-AMPARs is crucial in governing hyperexcitation and synaptic plasticity in GABAergic neurons.
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Affiliation(s)
- V. P. Zinchenko
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Institute of Cell Biophysics of the Russian Academy of Sciences, Institutskaya 3, Pushchino, Russia 142290
| | - L. P. Dolgacheva
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Institute of Cell Biophysics of the Russian Academy of Sciences, Institutskaya 3, Pushchino, Russia 142290
| | - S. T. Tuleukhanov
- Al-Farabi Kazakh National University, 050040 Al-Farabi Avenue 71, Almaty, Republic of Kazakhstan
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6
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Zhang W, Jin M, Lu Z, Li T, Wang H, Yuan Z, Wei C. Whole Genome Resequencing Reveals Selection Signals Related to Wool Color in Sheep. Animals (Basel) 2023; 13:3265. [PMID: 37893989 PMCID: PMC10603731 DOI: 10.3390/ani13203265] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/10/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
Wool color is controlled by a variety of genes. Although the gene regulation of some wool colors has been studied in relative depth, there may still be unknown genetic variants and control genes for some colors or different breeds of wool that need to be identified and recognized by whole genome resequencing. Therefore, we used whole genome resequencing data to compare and analyze sheep populations of different breeds by population differentiation index and nucleotide diversity ratios (Fst and θπ ratio) as well as extended haplotype purity between populations (XP-EHH) to reveal selection signals related to wool coloration in sheep. Screening in the non-white wool color group (G1 vs. G2) yielded 365 candidate genes, among which PDE4B, GMDS, GATA1, RCOR1, MAPK4, SLC36A1, and PPP3CA were associated with the formation of non-white wool; an enrichment analysis of the candidate genes yielded 21 significant GO terms and 49 significant KEGG pathways (p < 0.05), among which 17 GO terms and 21 KEGG pathways were associated with the formation of non-white wool. Screening in the white wool color group (G2 vs. G1) yielded 214 candidate genes, including ABCD4, VSX2, ITCH, NNT, POLA1, IGF1R, HOXA10, and DAO, which were associated with the formation of white wool; an enrichment analysis of the candidate genes revealed 9 significant GO-enriched pathways and 19 significant KEGG pathways (p < 0.05), including 5 GO terms and 12 KEGG pathways associated with the formation of white wool. In addition to furthering our understanding of wool color genetics, this research is important for breeding purposes.
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Affiliation(s)
- Wentao Zhang
- State Key Laboratory of Animal Biotech Breeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China; (W.Z.); (M.J.); (T.L.); (H.W.)
| | - Meilin Jin
- State Key Laboratory of Animal Biotech Breeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China; (W.Z.); (M.J.); (T.L.); (H.W.)
| | - Zengkui Lu
- Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou 730050, China;
| | - Taotao Li
- State Key Laboratory of Animal Biotech Breeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China; (W.Z.); (M.J.); (T.L.); (H.W.)
| | - Huihua Wang
- State Key Laboratory of Animal Biotech Breeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China; (W.Z.); (M.J.); (T.L.); (H.W.)
| | - Zehu Yuan
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, China;
| | - Caihong Wei
- State Key Laboratory of Animal Biotech Breeding, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences (CAAS), Beijing 100193, China; (W.Z.); (M.J.); (T.L.); (H.W.)
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7
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Bell MK, Lee CT, Rangamani P. Spatiotemporal modelling reveals geometric dependence of AMPAR dynamics on dendritic spine morphology. J Physiol 2023; 601:3329-3350. [PMID: 36326020 DOI: 10.1113/jp283407] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 11/01/2022] [Indexed: 08/02/2023] Open
Abstract
The modification of neural circuits depends on the strengthening and weakening of synaptic connections. Synaptic strength is often correlated to the density of the ionotropic, glutamatergic receptors, AMPARs, (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors) at the postsynaptic density (PSD). While AMPAR density is known to change based on complex biological signalling cascades, the effect of geometric factors such as dendritic spine shape, size and curvature remain poorly understood. In this work, we developed a deterministic, spatiotemporal model to study the dynamics of AMPARs during long-term potentiation (LTP). This model includes a minimal set of biochemical events that represent the upstream signalling events, trafficking of AMPARs to and from the PSD, lateral diffusion in the plane of the spine membrane, and the presence of an extrasynaptic AMPAR pool. Using idealized and realistic spine geometries, we show that the dynamics and increase of bound AMPARs at the PSD depends on a combination of endo- and exocytosis, membrane diffusion, the availability of free AMPARs and intracellular signalling interactions. We also found non-monotonic relationships between spine volume and the change in AMPARs at the PSD, suggesting that spines restrict changes in AMPARs to optimize resources and prevent runaway potentiation. KEY POINTS: Synaptic plasticity involves dynamic biochemical and physical remodelling of small protrusions called dendritic spines along the dendrites of neurons. Proper synaptic functionality within these spines requires changes in receptor number at the synapse, which has implications for downstream neural functions, such as learning and memory formation. In addition to being signalling subcompartments, spines also have unique morphological features that can play a role in regulating receptor dynamics on the synaptic surface. We have developed a spatiotemporal model that couples biochemical signalling and receptor trafficking modalities in idealized and realistic spine geometries to investigate the role of biochemical and biophysical factors in synaptic plasticity. Using this model, we highlight the importance of spine size and shape in regulating bound AMPA receptor dynamics that govern synaptic plasticity, and predict how spine shape might act to reset synaptic plasticity as a built-in resource optimization and regulation tool.
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Affiliation(s)
- Miriam K Bell
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA
| | - Christopher T Lee
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, USA
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8
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Xia X, Zhang G, Pica Ciamarra M, Jiao Y, Ni R. The Role of Receptor Uniformity in Multivalent Binding. JACS AU 2023; 3:1385-1391. [PMID: 37234107 PMCID: PMC10207130 DOI: 10.1021/jacsau.3c00052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/13/2023] [Accepted: 04/11/2023] [Indexed: 05/27/2023]
Abstract
Multivalency is prevalent in various biological systems and applications due to the superselectivity that arises from the cooperativity of multivalent binding. Traditionally, it was thought that weaker individual binding would improve the selectivity in multivalent targeting. Here, using analytical mean field theory and Monte Carlo simulations, we discover that, for receptors that are highly uniformly distributed, the highest selectivity occurs at an intermediate binding energy and can be significantly greater than the weak binding limit. This is caused by an exponential relationship between the bound fraction and receptor concentration, which is influenced by both the strength and combinatorial entropy of binding. Our findings not only provide new guidelines for the rational design of biosensors using multivalent nanoparticles but also introduce a new perspective in understanding biological processes involving multivalency.
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Affiliation(s)
- Xiuyang Xia
- School
of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, 637459 Singapore
- Division
of Physics and Applied Physics, School of Physical and Mathematical
Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore
| | - Ge Zhang
- Department
of Physics, City University of Hong Kong, 518057 Kowloon, Hong Kong China
| | - Massimo Pica Ciamarra
- Division
of Physics and Applied Physics, School of Physical and Mathematical
Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore
| | - Yang Jiao
- Materials
Science and Engineering, Arizona State University, Tempe, Arizona 85287, United States
| | - Ran Ni
- School
of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 62 Nanyang Drive, 637459 Singapore
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9
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Sun C, Schuman E. A multi-omics view of neuronal subcellular protein synthesis. Curr Opin Neurobiol 2023; 80:102705. [PMID: 36913750 DOI: 10.1016/j.conb.2023.102705] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 03/13/2023]
Abstract
While it has long been known that protein synthesis is necessary for long-term memory in the brain, the logistics of neuronal protein synthesis is complicated by the extensive subcellular compartmentalization of the neuron. Local protein synthesis solves many of the logistic problems posed by the extreme complexity of dendritic and axonal arbors and the huge number of synapses. Here we review recent multi-omic and quantitative studies that elaborate a systems view of decentralized neuronal protein synthesis. We highlight recent insights from the transcriptomic, translatomic, and proteomic levels, discuss the nuanced logic of local protein synthesis for different protein features, and list the missing information needed to build a comprehensive logistic model for neuronal protein supply.
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Affiliation(s)
- Chao Sun
- Max Planck Institute for Brain Research, Frankfurt, Germany; Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Denmark; Aarhus University, Department of Molecular Biology and Genetics, Universitetsbyen 81, 8000 Aarhus C, Denmark. https://twitter.com/LukeChaoSun
| | - Erin Schuman
- Max Planck Institute for Brain Research, Frankfurt, Germany.
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10
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Quantifying postsynaptic receptor dynamics: insights into synaptic function. Nat Rev Neurosci 2023; 24:4-22. [PMID: 36352031 DOI: 10.1038/s41583-022-00647-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2022] [Indexed: 11/11/2022]
Abstract
The molecular composition of presynaptic and postsynaptic neuronal terminals is dynamic, and yet long-term stabilizations in postsynaptic responses are necessary for synaptic development and long-term plasticity. The need to reconcile these concepts is further complicated by learning- and memory-related plastic changes in the molecular make-up of synapses. Advances in single-particle tracking mean that we can now quantify the number and diffusive properties of specific synaptic molecules, while statistical thermodynamics provides a framework to analyse these molecular fluctuations. In this Review, we discuss the use of these approaches to gain quantitative descriptions of the processes underlying the turnover, long-term stability and plasticity of postsynaptic receptors and show how these can help us to understand the balance between local molecular turnover and synaptic structural identity and integrity.
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11
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Michaluk P, Rusakov DA. Monitoring cell membrane recycling dynamics of proteins using whole-cell fluorescence recovery after photobleaching of pH-sensitive genetic tags. Nat Protoc 2022; 17:3056-3079. [PMID: 36064755 DOI: 10.1038/s41596-022-00732-4] [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: 11/21/2021] [Accepted: 06/07/2022] [Indexed: 11/08/2022]
Abstract
Population behavior of signaling molecules on the cell surface is key to their adaptive function. Live imaging of proteins tagged with fluorescent molecules has been an essential tool in understanding this behavior. Typically, genetic or chemical tags are used to target molecules present throughout the cell, whereas antibody-based tags label the externally exposed molecular domains only. Both approaches could potentially overlook the intricate process of in-out membrane recycling in which target molecules appear or disappear on the cell surface. This limitation is overcome by using a pH-sensitive fluorescent tag, such as Super-Ecliptic pHluorin (SEP), because its emission depends on whether it resides inside or outside the cell. Here we focus on the main glial glutamate transporter GLT1 and describe a genetic design that equips GLT1 molecules with SEP without interfering with the transporter's main function. Expressing GLT1-SEP in astroglia in cultures or in hippocampal slices enables monitoring of the real-time dynamics of the cell-surface and cytosolic fractions of the transporter in living cells. Whole-cell fluorescence recovery after photobleaching and quantitative image-kinetic analysis of the resulting time-lapse images enables assessment of the rate of GLT1-SEP recycling on the cell surface, a fundamental trafficking parameter unattainable previously. The present protocol takes 15-20 d to set up cell preparations, and 2-3 d to carry out live cell experiments and data analyses. The protocol can be adapted to study different membrane molecules of interest, particularly those proteins whose lifetime on the cell surface is critical to their adaptive function.
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Affiliation(s)
- Piotr Michaluk
- UCL Queen Square Institute of Neurology, University College London, London, UK.
- BRAINCITY, Laboratory of Neurobiology, Nencki Institute of Experimental Biology PAS, Warsaw, Poland.
| | - Dmitri A Rusakov
- UCL Queen Square Institute of Neurology, University College London, London, UK.
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12
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Barrantes FJ. Fluorescence microscopy imaging of a neurotransmitter receptor and its cell membrane lipid milieu. Front Mol Biosci 2022; 9:1014659. [PMID: 36518846 PMCID: PMC9743973 DOI: 10.3389/fmolb.2022.1014659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 11/01/2022] [Indexed: 05/02/2024] Open
Abstract
Hampered by the diffraction phenomenon, as expressed in 1873 by Abbe, applications of optical microscopy to image biological structures were for a long time limited to resolutions above the ∼200 nm barrier and restricted to the observation of stained specimens. The introduction of fluorescence was a game changer, and since its inception it became the gold standard technique in biological microscopy. The plasma membrane is a tenuous envelope of 4 nm-10 nm in thickness surrounding the cell. Because of its highly versatile spectroscopic properties and availability of suitable instrumentation, fluorescence techniques epitomize the current approach to study this delicate structure and its molecular constituents. The wide spectral range covered by fluorescence, intimately linked to the availability of appropriate intrinsic and extrinsic probes, provides the ability to dissect membrane constituents at the molecular scale in the spatial domain. In addition, the time resolution capabilities of fluorescence methods provide complementary high precision for studying the behavior of membrane molecules in the time domain. This review illustrates the value of various fluorescence techniques to extract information on the topography and motion of plasma membrane receptors. To this end I resort to a paradigmatic membrane-bound neurotransmitter receptor, the nicotinic acetylcholine receptor (nAChR). The structural and dynamic picture emerging from studies of this prototypic pentameric ligand-gated ion channel can be extrapolated not only to other members of this superfamily of ion channels but to other membrane-bound proteins. I also briefly discuss the various emerging techniques in the field of biomembrane labeling with new organic chemistry strategies oriented to applications in fluorescence nanoscopy, the form of fluorescence microscopy that is expanding the depth and scope of interrogation of membrane-associated phenomena.
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Affiliation(s)
- Francisco J. Barrantes
- Biomedical Research Institute (BIOMED), Catholic University of Argentina (UCA)–National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina
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13
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Martín MG, Dotti CG. Plasma membrane and brain dysfunction of the old: Do we age from our membranes? Front Cell Dev Biol 2022; 10:1031007. [PMID: 36274849 PMCID: PMC9582647 DOI: 10.3389/fcell.2022.1031007] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 09/20/2022] [Indexed: 11/26/2022] Open
Abstract
One of the characteristics of aging is a gradual hypo-responsiveness of cells to extrinsic stimuli, mainly evident in the pathways that are under hormone control, both in the brain and in peripheral tissues. Age-related resistance, i.e., reduced response of receptors to their ligands, has been shown to Insulin and also to leptin, thyroid hormones and glucocorticoids. In addition, lower activity has been reported in aging for ß-adrenergic receptors, adenosine A2B receptor, and several other G-protein-coupled receptors. One of the mechanisms proposed to explain the loss of sensitivity to hormones and neurotransmitters with age is the loss of receptors, which has been observed in several tissues. Another mechanism that is finding more and more experimental support is related to the changes that occur with age in the lipid composition of the neuronal plasma membrane, which are responsible for changes in the receptors’ coupling efficiency to ligands, signal attenuation and pathway desensitization. In fact, recent works have shown that altered membrane composition—as occurs during neuronal aging—underlies reduced response to glutamate, to the neurotrophin BDNF, and to insulin, all these leading to cognition decay and epigenetic alterations in the old. In this review we present evidence that altered functions of membrane receptors due to altered plasma membrane properties may be a triggering factor in physiological decline, decreased brain function, and increased vulnerability to neuropathology in aging.
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Affiliation(s)
- Mauricio G. Martín
- Cellular and Molecular Neurobiology Department, Instituto Ferreyra (INIMEC)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Córdoba (UNC), Córdoba, Argentina
- *Correspondence: Mauricio G. Martín, ; Carlos G. Dotti,
| | - Carlos G. Dotti
- Molecular Neuropathology Unit, Physiological and Pathological Processes Program, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Madrid, Spain
- *Correspondence: Mauricio G. Martín, ; Carlos G. Dotti,
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14
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Li X, Hémond G, Godin AG, Doyon N. Computational modeling of trans-synaptic nanocolumns, a modulator of synaptic transmission. Front Comput Neurosci 2022; 16:969119. [PMID: 36249484 PMCID: PMC9554614 DOI: 10.3389/fncom.2022.969119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 09/01/2022] [Indexed: 12/01/2022] Open
Abstract
Understanding synaptic transmission is of crucial importance in neuroscience. The spatial organization of receptors, vesicle release properties and neurotransmitter molecule diffusion can strongly influence features of synaptic currents. Newly discovered structures coined trans-synaptic nanocolumns were shown to align presynaptic vesicles release sites and postsynaptic receptors. However, how these structures, spanning a few tens of nanometers, shape synaptic signaling remains little understood. Given the difficulty to probe submicroscopic structures experimentally, computer modeling is a useful approach to investigate the possible functional impacts and role of nanocolumns. In our in silico model, as has been experimentally observed, a nanocolumn is characterized by a tight distribution of postsynaptic receptors aligned with the presynaptic vesicle release site and by the presence of trans-synaptic molecules which can modulate neurotransmitter molecule diffusion. In this work, we found that nanocolumns can play an important role in reinforcing synaptic current mostly when the presynaptic vesicle contains a small number of neurotransmitter molecules. Our work proposes a new methodology to investigate in silico how the existence of trans-synaptic nanocolumns, the nanometric organization of the synapse and the lateral diffusion of receptors shape the features of the synaptic current such as its amplitude and kinetics.
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Affiliation(s)
- Xiaoting Li
- Department of Mathematics and Statistics, Université Laval, Québec City, QC, Canada
- Department of Psychiatry and Neuroscience, Université Laval, Québec City, QC, Canada
- CERVO Brain Research Centre, Québec City, QC, Canada
| | - Gabriel Hémond
- Department of Physics, Université Laval, Québec City, QC, Canada
| | - Antoine G. Godin
- Department of Psychiatry and Neuroscience, Université Laval, Québec City, QC, Canada
- CERVO Brain Research Centre, Québec City, QC, Canada
- *Correspondence: Antoine G. Godin
| | - Nicolas Doyon
- Department of Mathematics and Statistics, Université Laval, Québec City, QC, Canada
- CERVO Brain Research Centre, Québec City, QC, Canada
- Nicolas Doyon
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15
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Saavedra LA, Buena-Maizón H, Barrantes FJ. Mapping the Nicotinic Acetylcholine Receptor Nanocluster Topography at the Cell Membrane with STED and STORM Nanoscopies. Int J Mol Sci 2022; 23:ijms231810435. [PMID: 36142349 PMCID: PMC9499342 DOI: 10.3390/ijms231810435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/01/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
The cell-surface topography and density of nicotinic acetylcholine receptors (nAChRs) play a key functional role in the synapse. Here we employ in parallel two labeling and two super-resolution microscopy strategies to characterize the distribution of this receptor at the plasma membrane of the mammalian clonal cell line CHO-K1/A5. Cells were interrogated with two targeted techniques (confocal microscopy and stimulated emission depletion (STED) nanoscopy) and single-molecule nanoscopy (stochastic optical reconstruction microscopy, STORM) using the same fluorophore, Alexa Fluor 647, tagged onto either α-bungarotoxin (BTX) or the monoclonal antibody mAb35. Analysis of the topography of nanometer-sized aggregates (“nanoclusters”) was carried out using STORMGraph, a quantitative clustering analysis for single-molecule localization microscopy based on graph theory and community detection, and ASTRICS, an inter-cluster similarity algorithm based on computational geometry. Antibody-induced crosslinking of receptors resulted in nanoclusters with a larger number of receptor molecules and higher densities than those observed in BTX-labeled samples. STORM and STED provided complementary information, STED rendering a direct map of the mesoscale nAChR distribution at distances ~10-times larger than the nanocluster centroid distances measured in STORM samples. By applying photon threshold filtering analysis, we show that it is also possible to detect the mesoscale organization in STORM images.
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16
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Schumm RD, Bressloff PC. Local accumulation times in a diffusion-trapping model of receptor dynamics at proximal axodendritic synapses. Phys Rev E 2022; 105:064407. [PMID: 35854532 DOI: 10.1103/physreve.105.064407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/18/2022] [Indexed: 11/07/2022]
Abstract
The lateral diffusion and trapping of neurotransmitter receptors within the postsynaptic membrane of a neuron play a key role in determining synaptic strength and plasticity. Trapping is mediated by the reversible binding of receptors to scaffolding proteins (slots) within a synapse. In this paper we introduce a method for analyzing the transient dynamics of proximal axodendritic synapses in a diffusion-trapping model of receptor trafficking. Given a population of spatially distributed synapses, each of which has a fixed number of slots, we calculate the rate of relaxation to the steady-state distribution of bound slots (synaptic weights) in terms of a set of local accumulation times. Assuming that the rates of exocytosis and endocytosis are sufficiently slow, we show that the steady-state synaptic weights are independent of each other (purely local). On the other hand, the local accumulation time of a given synapse depends on the number of slots and the spatial location of all the synapses, indicating a form of transient heterosynaptic plasticity. This suggests that local accumulation time measurements could provide useful information regarding the distribution of synaptic weights within a dendrite.
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Affiliation(s)
- Ryan D Schumm
- Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, Utah 84112, USA
| | - P C Bressloff
- Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, Utah 84112, USA
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17
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Bonilla-Quintana M, Rangamani P. Can biophysical models of dendritic spines be used to explore synaptic changes associated with addiction? Phys Biol 2022; 19. [PMID: 35508164 DOI: 10.1088/1478-3975/ac6cbe] [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: 01/06/2022] [Accepted: 05/04/2022] [Indexed: 11/11/2022]
Abstract
Effective treatments that prevent or reduce drug relapse vulnerability should be developed to relieve the high burden of drug addiction on society. This will only be possible by enhancing the understanding of the molecular mechanisms underlying the neurobiology of addiction. Recent experimental data have shown that dendritic spines, small protrusions from the dendrites that receive excitatory input, of spiny neurons in the nucleus accumbens exhibit morphological changes during drug exposure and withdrawal. Moreover, these changes relate to the characteristic drug-seeking behavior of addiction. However, due to the complexity of the dendritic spines, we do not yet fully understand the processes underlying their structural changes in response to different inputs. We propose that biophysical models can enhance the current understanding of these processes by incorporating different, and sometimes, discrepant experimental data to identify the shared underlying mechanisms and generate experimentally testable hypotheses. This review aims to give an up-to-date report on biophysical models of dendritic spines, focusing on those models that describe their shape changes, which are well-known to relate to learning and memory. Moreover, it examines how these models can enhance our understanding of the effect of the drugs and the synaptic changes during withdrawal, as well as during neurodegenerative disease progression such as Alzheimer's disease.
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Affiliation(s)
- Mayte Bonilla-Quintana
- Mechanical Aerospace Engineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California, 92093-0021, UNITED STATES
| | - Padmini Rangamani
- Mechanical Aerospace Engineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California, 92093-0021, UNITED STATES
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18
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Abstract
N-methyl-d-aspartate receptors (NMDARs) and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs) are excitatory neurotransmission receptors of the central nervous system and play vital roles in synaptic plasticity. Although not fully elucidated, visceral hypersensitivity is one of the most well-characterized pathophysiologic abnormalities of functional gastrointestinal diseases and appears to be associated with increased synaptic plasticity. In this study, we review the updated findings on the physiology of NMDARs and AMPARs and their relation to visceral hypersensitivity, which propose directions for future research in this field with evolving importance.
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Abstract
The last century was characterized by a significant scientific effort aimed at unveiling the neurobiological basis of learning and memory. Thanks to the characterization of the mechanisms regulating the long-term changes of neuronal synaptic connections, it was possible to understand how specific neural networks shape themselves during the acquisition of memory traces or complex motor tasks. In this chapter, we will summarize the mechanisms underlying the main forms of synaptic plasticity taking advantage of the studies performed in the hippocampus and in the nucleus striatum, key brain structures that play a crucial role in cognition. Moreover, we will discuss how the molecular pathways involved in the induction of physiologic synaptic long-term changes could be disrupted during neurodegenerative and neuroinflammatory disorders, highlighting the translational relevance of this intriguing research field.
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Affiliation(s)
- Andrea Mancini
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, Perugia, Italy.
| | - Antonio de Iure
- IRCCS San Raffaele Roma, Laboratory of Experimental Neurophysiology, Rome, Italy
| | - Barbara Picconi
- IRCCS San Raffaele Roma, Laboratory of Experimental Neurophysiology, Rome, Italy; University San Raffaele, Rome, Italy.
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20
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Zhang Y, Li L, Wang J. Tuning cellular uptake of nanoparticles via ligand density: Contribution of configurational entropy. Phys Rev E 2021; 104:054405. [PMID: 34942735 DOI: 10.1103/physreve.104.054405] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 10/25/2021] [Indexed: 01/01/2023]
Abstract
The bioactivity of nanoparticles (NPs) crucially depends on their ability to cross biological membranes. A fundamental understanding of cell-NP interaction is hence essential to improve the performance of the NP-based biomedical applications. Although extensive studies of cellular uptake have converged upon the idea that the uptake process is mainly regulated by the elastic deformation of the cell membrane or NP, recent experimental observations indicate the ligand density as another critical factor in modulating NP uptake into cells. In this study, we propose a theoretical model of the wrapping of an elastic vesicle NP by a finite lipid membrane to depict the relevant energetic and morphological evolutions during the wrapping process driven by forming receptor-ligand bonds. In this model, the deformations of the membrane and the vesicle NP are assumed to follow the continuum Canham-Helfrich framework, whereas the change of configurational entropy of receptors is described from statistical thermodynamics. Results show that the ligand density strongly affects the binding energy and configurational entropy of free receptors, thereby altering the morphology of the vesicle-membrane system in the steady wrapping state. For the wrapping process by the finite lipid membrane, we also find that there exists optimal ligand density for the maximum wrapping degree. These predictions are consistent with relevant experimental observations reported in the literature. We have further observed that there are transitions of various wrapping phases (no wrapping, partial wrapping, and full wrapping) in terms of ligand density, membrane tension, and molecular binding energy. In particular, the ligand and receptor shortage regimes for the small and high ligand density are, respectively, identified. These results may provide guidelines for the rational design of nanocarriers for drug delivery.
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Affiliation(s)
- Yudie Zhang
- Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000, China
| | - Long Li
- Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000, China.,PULS Group, Institute for Theoretical Physics, FAU Erlangen-Nürnberg, Erlangen 91058, Germany
| | - Jizeng Wang
- Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000, China
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21
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Kopach O, Voitenko N. Spinal AMPA receptors: Amenable players in central sensitization for chronic pain therapy? Channels (Austin) 2021; 15:284-297. [PMID: 33565904 PMCID: PMC7889122 DOI: 10.1080/19336950.2021.1885836] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 02/01/2021] [Accepted: 02/01/2021] [Indexed: 02/08/2023] Open
Abstract
The activity-dependent trafficking of AMPA receptors (AMPAR) mediates synaptic strength and plasticity, while the perturbed trafficking of the receptors of different subunit compositions has been linked to memory impairment and to causing neuropathology. In the spinal cord, nociceptive-induced changes in AMPAR trafficking determine the central sensitization of the dorsal horn (DH): changes in AMPAR subunit composition compromise the balance between synaptic excitation and inhibition, rendering interneurons hyperexcitable to afferent inputs, and promoting Ca2+ influx into the DH neurons, thereby amplifying neuronal hyperexcitability. The DH circuits become over-excitable and carry out aberrant sensory processing; this causes an increase in pain sensation in central sensory pathways, giving rise to chronic pain syndrome. Current knowledge of the contribution of spinal AMPAR to the cellular mechanisms relating to chronic pain provides opportunities for developing target-based therapies for chronic pain intervention.
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Affiliation(s)
- Olga Kopach
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
- Present Address: Department of Clinical and Experimental Epilepsy, Queen Square Institute of Neurology, University College London, London, UK
| | - Nana Voitenko
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
- Kyiv Academic University, Kyiv, Ukraine
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22
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Vallés AS, Barrantes FJ. Nanoscale Sub-Compartmentalization of the Dendritic Spine Compartment. Biomolecules 2021; 11:1697. [PMID: 34827695 PMCID: PMC8615865 DOI: 10.3390/biom11111697] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 01/04/2023] Open
Abstract
Compartmentalization of the membrane is essential for cells to perform highly specific tasks and spatially constrained biochemical functions in topographically defined areas. These membrane lateral heterogeneities range from nanoscopic dimensions, often involving only a few molecular constituents, to micron-sized mesoscopic domains resulting from the coalescence of nanodomains. Short-lived domains lasting for a few milliseconds coexist with more stable platforms lasting from minutes to days. This panoply of lateral domains subserves the great variety of demands of cell physiology, particularly high for those implicated in signaling. The dendritic spine, a subcellular structure of neurons at the receiving (postsynaptic) end of central nervous system excitatory synapses, exploits this compartmentalization principle. In its most frequent adult morphology, the mushroom-shaped spine harbors neurotransmitter receptors, enzymes, and scaffolding proteins tightly packed in a volume of a few femtoliters. In addition to constituting a mesoscopic lateral heterogeneity of the dendritic arborization, the dendritic spine postsynaptic membrane is further compartmentalized into spatially delimited nanodomains that execute separate functions in the synapse. This review discusses the functional relevance of compartmentalization and nanodomain organization in synaptic transmission and plasticity and exemplifies the importance of this parcelization in various neurotransmitter signaling systems operating at dendritic spines, using two fast ligand-gated ionotropic receptors, the nicotinic acetylcholine receptor and the glutamatergic receptor, and a second-messenger G-protein coupled receptor, the cannabinoid receptor, as paradigmatic examples.
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Affiliation(s)
- Ana Sofía Vallés
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (UNS-CONICET), Bahía Blanca 8000, Argentina;
| | - Francisco J. Barrantes
- Laboratory of Molecular Neurobiology, Institute of Biomedical Research (BIOMED), UCA-CONICET, Av. Alicia Moreau de Justo 1600, Buenos Aires C1107AFF, Argentina
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23
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Sun C, Nold A, Fusco CM, Rangaraju V, Tchumatchenko T, Heilemann M, Schuman EM. The prevalence and specificity of local protein synthesis during neuronal synaptic plasticity. SCIENCE ADVANCES 2021; 7:eabj0790. [PMID: 34533986 PMCID: PMC8448450 DOI: 10.1126/sciadv.abj0790] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
To supply proteins to their vast volume, neurons localize mRNAs and ribosomes in dendrites and axons. While local protein synthesis is required for synaptic plasticity, the abundance and distribution of ribosomes and nascent proteins near synapses remain elusive. Here, we quantified the occurrence of local translation and visualized the range of synapses supplied by nascent proteins during basal and plastic conditions. We detected dendritic ribosomes and nascent proteins at single-molecule resolution using DNA-PAINT and metabolic labeling. Both ribosomes and nascent proteins positively correlated with synapse density. Ribosomes were detected at ~85% of synapses with ~2 translational sites per synapse; ~50% of the nascent protein was detected near synapses. The amount of locally synthesized protein detected at a synapse correlated with its spontaneous Ca2+ activity. A multifold increase in synaptic nascent protein was evident following both local and global plasticity at respective scales, albeit with substantial heterogeneity between neighboring synapses.
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Affiliation(s)
- Chao Sun
- Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Andreas Nold
- Max Planck Institute for Brain Research, Frankfurt, Germany
- Institute of Experimental Epileptology and Cognition Research, Life and Brain Center, Universitätsklinikum Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | | | | | - Tatjana Tchumatchenko
- Max Planck Institute for Brain Research, Frankfurt, Germany
- Institute of Experimental Epileptology and Cognition Research, Life and Brain Center, Universitätsklinikum Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe University, Frankfurt, Germany
| | - Erin M. Schuman
- Max Planck Institute for Brain Research, Frankfurt, Germany
- Corresponding author.
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24
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Law E, Li Y, Kahraman O, Haselwandter CA. Stochastic self-assembly of reaction-diffusion patterns in synaptic membranes. Phys Rev E 2021; 104:014403. [PMID: 34412234 DOI: 10.1103/physreve.104.014403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 06/14/2021] [Indexed: 11/07/2022]
Abstract
Synaptic receptor and scaffold molecules self-assemble into membrane protein domains, which play an important role in signal transmission across chemical synapses. Experiment and theory have shown that the formation of receptor-scaffold domains of the characteristic size observed in nerve cells can be understood from the receptor and scaffold reaction and diffusion processes suggested by experiments. We employ here kinetic Monte Carlo (KMC) simulations to explore the self-assembly of synaptic receptor-scaffold domains in a stochastic lattice model of receptor and scaffold reaction-diffusion dynamics. For reaction and diffusion rates within the ranges of values suggested by experiments we find, in agreement with previous mean-field calculations, self-assembly of receptor-scaffold domains of a size similar to that observed in experiments. Comparisons between the results of our KMC simulations and mean-field solutions suggest that the intrinsic noise associated with receptor and scaffold reaction and diffusion processes accelerates the self-assembly of receptor-scaffold domains, and confers increased robustness to domain formation. In agreement with experimental observations, our KMC simulations yield a prevalence of scaffolds over receptors in receptor-scaffold domains. Our KMC simulations show that receptor and scaffold reaction-diffusion dynamics can inherently give rise to plasticity in the overall properties of receptor-scaffold domains, which may be utilized by nerve cells to regulate the receptor number at chemical synapses.
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Affiliation(s)
- Everest Law
- Department of Physics and Astronomy and Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California 90089, USA
| | - Yiwei Li
- Department of Physics and Astronomy and Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California 90089, USA
| | - Osman Kahraman
- Department of Physics and Astronomy and Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California 90089, USA
| | - Christoph A Haselwandter
- Department of Physics and Astronomy and Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, California 90089, USA
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25
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Rapid Ca 2+ channel accumulation contributes to cAMP-mediated increase in transmission at hippocampal mossy fiber synapses. Proc Natl Acad Sci U S A 2021; 118:2016754118. [PMID: 33622791 DOI: 10.1073/pnas.2016754118] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The cyclic adenosine monophosphate (cAMP)-dependent potentiation of neurotransmitter release is important for higher brain functions such as learning and memory. To reveal the underlying mechanisms, we applied paired pre- and postsynaptic recordings from hippocampal mossy fiber-CA3 synapses. Ca2+ uncaging experiments did not reveal changes in the intracellular Ca2+ sensitivity for transmitter release by cAMP, but suggested an increase in the local Ca2+ concentration at the release site, which was much lower than that of other synapses before potentiation. Total internal reflection fluorescence (TIRF) microscopy indicated a clear increase in the local Ca2+ concentration at the release site within 5 to 10 min, suggesting that the increase in local Ca2+ is explained by the simple mechanism of rapid Ca2+ channel accumulation. Consistently, two-dimensional time-gated stimulated emission depletion microscopy (gSTED) microscopy showed an increase in the P/Q-type Ca2+ channel cluster size near the release sites. Taken together, this study suggests a potential mechanism for the cAMP-dependent increase in transmission at hippocampal mossy fiber-CA3 synapses, namely an accumulation of active zone Ca2+ channels.
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26
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Ramsey AM, Tang AH, LeGates TA, Gou XZ, Carbone BE, Thompson SM, Biederer T, Blanpied TA. Subsynaptic positioning of AMPARs by LRRTM2 controls synaptic strength. SCIENCE ADVANCES 2021; 7:7/34/eabf3126. [PMID: 34417170 PMCID: PMC8378824 DOI: 10.1126/sciadv.abf3126] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 06/30/2021] [Indexed: 05/07/2023]
Abstract
Recent evidence suggests that nano-organization of proteins within synapses may control the strength of communication between neurons in the brain. The unique subsynaptic distribution of glutamate receptors, which cluster in nanoalignment with presynaptic sites of glutamate release, supports this hypothesis. However, testing it has been difficult because mechanisms controlling subsynaptic organization remain unknown. Reasoning that transcellular interactions could position AMPA receptors (AMPARs), we targeted a key transsynaptic adhesion molecule implicated in controlling AMPAR number, LRRTM2, using engineered, rapid proteolysis. Severing the LRRTM2 extracellular domain led quickly to nanoscale declustering of AMPARs away from release sites, not prompting their escape from synapses until much later. This rapid remodeling of AMPAR position produced significant deficits in evoked, but not spontaneous, postsynaptic receptor activation. These results dissociate receptor numbers from their nanopositioning in determination of synaptic function and support the novel concept that adhesion molecules acutely position receptors to dynamically control synaptic strength.
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Affiliation(s)
- Austin M Ramsey
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Ai-Hui Tang
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Tara A LeGates
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | - Beatrice E Carbone
- Department of Neurology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Scott M Thompson
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Thomas Biederer
- Department of Neurology, Yale School of Medicine, New Haven, CT 06520, USA
| | - Thomas A Blanpied
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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27
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Maingret F, Groc L. Characterization of the Functional Cross-Talk between Surface GABA A and Dopamine D5 Receptors. Int J Mol Sci 2021; 22:4867. [PMID: 34064454 PMCID: PMC8125140 DOI: 10.3390/ijms22094867] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/27/2021] [Accepted: 04/30/2021] [Indexed: 01/17/2023] Open
Abstract
The γ-aminobutyric acid type A receptor (GABAAR) plays a major role in fast inhibitory synaptic transmission and is highly regulated by the neuromodulator dopamine. In this aspect, most of the attention has been focused on the classical intracellular signaling cascades following dopamine G-protein-coupled receptor activation. Interestingly, the GABAAR and dopamine D5 receptor (D5R) have been shown to physically interact in the hippocampus, but whether a functional cross-talk occurs is still debated. In the present study, we use a combination of imaging and single nanoparticle tracking in live hippocampal neurons to provide evidence that GABAARs and D5Rs form dynamic surface clusters. Disrupting the GABAAR-D5R interaction with a competing peptide leads to an increase in the diffusion coefficient and the explored area of both receptors, and a drop in immobile synaptic GABAARs. By means of patch-clamp recordings, we show that this fast lateral redistribution of surface GABAARs correlates with a robust depression in the evoked GABAergic currents. Strikingly, it also shifts in time the expression of long-term potentiation at glutamatergic synapses. Together, our data both set the plasma membrane as the primary stage of a functional interplay between GABAAR and D5R, and uncover a non-canonical role in regulating synaptic transmission.
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Affiliation(s)
- François Maingret
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, UMR 5297, 33076 Bordeaux, France;
- CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33076 Bordeaux, France
| | - Laurent Groc
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, UMR 5297, 33076 Bordeaux, France;
- CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33076 Bordeaux, France
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28
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Dolgacheva LP, Tuleukhanov ST, Zinchenko VP. Participation of Ca2+-Permeable AMPA Receptors in Synaptic Plasticity. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2020. [DOI: 10.1134/s1990747820030046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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29
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Fricke S, Metzdorf K, Ohm M, Haak S, Heine M, Korte M, Zagrebelsky M. Fast Regulation of GABA AR Diffusion Dynamics by Nogo-A Signaling. Cell Rep 2020; 29:671-684.e6. [PMID: 31618635 DOI: 10.1016/j.celrep.2019.09.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/02/2019] [Accepted: 09/06/2019] [Indexed: 12/29/2022] Open
Abstract
Precisely controlling the excitatory and inhibitory balance is crucial for the stability and information-processing ability of neuronal networks. However, the molecular mechanisms maintaining this balance during ongoing sensory experiences are largely unclear. We show that Nogo-A signaling reciprocally regulates excitatory and inhibitory transmission. Loss of function for Nogo-A signaling through S1PR2 rapidly increases GABAAR diffusion, thereby decreasing their number at synaptic sites and the amplitude of GABAergic mIPSCs at CA3 hippocampal neurons. This increase in GABAAR diffusion rate is correlated with an increase in Ca2+ influx and requires the calcineurin-mediated dephosphorylation of the γ2 subunit at serine 327. These results suggest that Nogo-A signaling rapidly strengthens inhibitory GABAergic transmission by restricting the diffusion dynamics of GABAARs. Together with the observation that Nogo-A signaling regulates excitatory transmission in an opposite manner, these results suggest a crucial role for Nogo-A signaling in modulating the excitation and inhibition balance to restrict synaptic plasticity.
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Affiliation(s)
- Steffen Fricke
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany
| | - Kristin Metzdorf
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany
| | - Melanie Ohm
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany
| | - Stefan Haak
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany
| | - Martin Heine
- Molecular Physiology Group, Leibniz Institute of Neurobiology, Magdeburg 39118, Germany; Functional Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University, Mainz 55128, Germany
| | - Martin Korte
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany; Helmholtz Centre for Infection Research, AG NIND, Inhoffenstr. 7, Braunschweig 38124, Germany
| | - Marta Zagrebelsky
- Zoological Institute, Division of Cellular Neurobiology, TU Braunschweig, Braunschweig 38108, Germany.
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Mancini A, Mazzocchetti P, Sciaccaluga M, Megaro A, Bellingacci L, Beccano-Kelly DA, Di Filippo M, Tozzi A, Calabresi P. From Synaptic Dysfunction to Neuroprotective Strategies in Genetic Parkinson's Disease: Lessons From LRRK2. Front Cell Neurosci 2020; 14:158. [PMID: 32848606 PMCID: PMC7399363 DOI: 10.3389/fncel.2020.00158] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 05/12/2020] [Indexed: 12/11/2022] Open
Abstract
The pathogenesis of Parkinson’s disease (PD) is thought to rely on a complex interaction between the patient’s genetic background and a variety of largely unknown environmental factors. In this scenario, the investigation of the genetic bases underlying familial PD could unveil key molecular pathways to be targeted by new disease-modifying therapies, still currently unavailable. Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are responsible for the majority of inherited familial PD cases and can also be found in sporadic PD, but the pathophysiological functions of LRRK2 have not yet been fully elucidated. Here, we will review the evidence obtained in transgenic LRRK2 experimental models, characterized by altered striatal synaptic transmission, mitochondrial dysfunction, and α-synuclein aggregation. Interestingly, the processes triggered by mutant LRRK2 might represent early pathological phenomena in the pathogenesis of PD, anticipating the typical neurodegenerative features characterizing the late phases of the disease. A comprehensive view of LRRK2 neuronal pathophysiology will support the possible clinical application of pharmacological compounds targeting this protein, with potential therapeutic implications for patients suffering from both familial and sporadic PD.
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Affiliation(s)
- Andrea Mancini
- Section of Neurology, Department of Medicine, University of Perugia, Perugia, Italy
| | - Petra Mazzocchetti
- Section of Neurology, Department of Medicine, University of Perugia, Perugia, Italy
| | - Miriam Sciaccaluga
- Section of Neurology, Department of Medicine, University of Perugia, Perugia, Italy
| | - Alfredo Megaro
- Section of Neurology, Department of Medicine, University of Perugia, Perugia, Italy
| | - Laura Bellingacci
- Section of Physiology and Biochemistry, Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Dayne A Beccano-Kelly
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | | | - Alessandro Tozzi
- Section of Physiology and Biochemistry, Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Paolo Calabresi
- Neurologia, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Rome, Italy.,Neuroscience Department, Università Cattolica del Sacro Cuore, Rome, Italy
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31
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Garzon Dasgupta AK, Martyanov AA, Filkova AA, Panteleev MA, Sveshnikova AN. Development of a Simple Kinetic Mathematical Model of Aggregation of Particles or Clustering of Receptors. Life (Basel) 2020; 10:E97. [PMID: 32604803 PMCID: PMC7345685 DOI: 10.3390/life10060097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 06/24/2020] [Indexed: 12/24/2022] Open
Abstract
The process of clustering of plasma membrane receptors in response to their agonist is the first step in signal transduction. The rate of the clustering process and the size of the clusters determine further cell responses. Here we aim to demonstrate that a simple 2-differential equation mathematical model is capable of quantitative description of the kinetics of 2D or 3D cluster formation in various processes. Three mathematical models based on mass action kinetics were considered and compared with each other by their ability to describe experimental data on GPVI or CR3 receptor clustering (2D) and albumin or platelet aggregation (3D) in response to activation. The models were able to successfully describe experimental data without losing accuracy after switching between complex and simple models. However, additional restrictions on parameter values are required to match a single set of parameters for the given experimental data. The extended clustering model captured several properties of the kinetics of cluster formation, such as the existence of only three typical steady states for this system: unclustered receptors, receptor dimers, and clusters. Therefore, a simple kinetic mass-action-law-based model could be utilized to adequately describe clustering in response to activation both in 2D and in 3D.
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Affiliation(s)
- Andrei K. Garzon Dasgupta
- Faculty of Physics, Lomonosov Moscow State University, 1/2 Leninskie gory, 119991 Moscow, Russia; (A.K.G.D.); (A.A.M.); (A.A.F.); (M.A.P.)
- National Medical Research Centеr of Pediatric Hematology, Oncology and Immunology named after Dmitry Rogachev, 1 Samory Mashela St, 117198 Moscow, Russia
| | - Alexey A. Martyanov
- Faculty of Physics, Lomonosov Moscow State University, 1/2 Leninskie gory, 119991 Moscow, Russia; (A.K.G.D.); (A.A.M.); (A.A.F.); (M.A.P.)
- National Medical Research Centеr of Pediatric Hematology, Oncology and Immunology named after Dmitry Rogachev, 1 Samory Mashela St, 117198 Moscow, Russia
- Institute for Biochemical Physics (IBCP), Russian Academy of Sciences (RAS), Russian Federation, Kosyigina 4, 119334 Moscow, Russia
- Center for Theoretical Problems of Physico-Сhemical Pharmacology, Russian Academy of Sciences, 30 Srednyaya Kalitnikovskaya str., 109029 Moscow, Russia
| | - Aleksandra A. Filkova
- Faculty of Physics, Lomonosov Moscow State University, 1/2 Leninskie gory, 119991 Moscow, Russia; (A.K.G.D.); (A.A.M.); (A.A.F.); (M.A.P.)
- National Medical Research Centеr of Pediatric Hematology, Oncology and Immunology named after Dmitry Rogachev, 1 Samory Mashela St, 117198 Moscow, Russia
- Center for Theoretical Problems of Physico-Сhemical Pharmacology, Russian Academy of Sciences, 30 Srednyaya Kalitnikovskaya str., 109029 Moscow, Russia
| | - Mikhail A. Panteleev
- Faculty of Physics, Lomonosov Moscow State University, 1/2 Leninskie gory, 119991 Moscow, Russia; (A.K.G.D.); (A.A.M.); (A.A.F.); (M.A.P.)
- National Medical Research Centеr of Pediatric Hematology, Oncology and Immunology named after Dmitry Rogachev, 1 Samory Mashela St, 117198 Moscow, Russia
- Center for Theoretical Problems of Physico-Сhemical Pharmacology, Russian Academy of Sciences, 30 Srednyaya Kalitnikovskaya str., 109029 Moscow, Russia
- Faculty of Biological and Medical Physics, Moscow Institute of Physics and Technology, 9 Institutskii per., 141700 Dolgoprudnyi, Russia
| | - Anastasia N. Sveshnikova
- Faculty of Physics, Lomonosov Moscow State University, 1/2 Leninskie gory, 119991 Moscow, Russia; (A.K.G.D.); (A.A.M.); (A.A.F.); (M.A.P.)
- National Medical Research Centеr of Pediatric Hematology, Oncology and Immunology named after Dmitry Rogachev, 1 Samory Mashela St, 117198 Moscow, Russia
- Center for Theoretical Problems of Physico-Сhemical Pharmacology, Russian Academy of Sciences, 30 Srednyaya Kalitnikovskaya str., 109029 Moscow, Russia
- Department of Normal Physiology, Sechenov First Moscow State Medical University, 8/2 Trubetskaya St., 119991 Moscow, Russia
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32
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Shaw JE, Koleske AJ. Functional interactions of ion channels with the actin cytoskeleton: does coupling to dynamic actin regulate NMDA receptors? J Physiol 2020; 599:431-441. [PMID: 32034761 DOI: 10.1113/jp278702] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/14/2020] [Indexed: 01/12/2023] Open
Abstract
Synapses are enriched in the cytoskeletal protein actin, which determines the shape of the pre- and postsynaptic compartments, organizes the neurotransmitter release machinery, and provides a framework for trafficking of components. In the postsynaptic compartment, interactions with actin or its associated proteins are also critical for the localization and activity of synaptic neurotransmitter receptors and ion channels. Actin binding proteins, including spectrin and α-actinin, serve as molecular linkages between the actin cytoskeleton and a diverse collection of receptors, including the NMDA receptor (NMDAR) and voltage-gated Na+ channels. The actin cytoskeleton can regulate neurotransmitter receptors and ion channels by controlling their trafficking and localization at the synapse and by directly gating receptor channel opening. We highlight evidence that synaptic actin couples physically and functionally to the NMDAR and supports its activity. The molecular mechanisms by which actin regulates NMDARs are only just emerging, and recent advancements in light and electron microscopy-based imaging techniques should aide in elucidating these mechanisms.
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Affiliation(s)
- Juliana E Shaw
- Department of Molecular Biophysics and Biochemistry , Yale University, New Haven, CT, 06520, USA
| | - Anthony J Koleske
- Department of Molecular Biophysics and Biochemistry , Yale University, New Haven, CT, 06520, USA.,Department of Neuroscience, Yale University, New Haven, CT, 06520, USA
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33
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Linking Nanoscale Dynamics of AMPA Receptor Organization to Plasticity of Excitatory Synapses and Learning. J Neurosci 2019; 38:9318-9329. [PMID: 30381423 DOI: 10.1523/jneurosci.2119-18.2018] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/21/2018] [Accepted: 09/21/2018] [Indexed: 11/21/2022] Open
Abstract
The spatiotemporal organization of neurotransmitter receptors in the postsynaptic membrane is a fundamental determinant of synaptic transmission and thus of information processing by the brain. The ionotropic AMPA subtype of glutamate receptors (AMPARs) mediate fast excitatory synaptic transmission in the CNS. The number of AMPARs located en face presynaptic glutamate release sites sets the efficacy of synaptic transmission. Understanding how this number is set and regulated has been the topic of intense research in the last two decades. We showed that AMPARs are not stable in the synapse as initially thought. They continuously enter and exit the postsynaptic density by lateral diffusion, and they exchange between the neuronal surface and intracellular compartments by endocytosis and exocytosis at extrasynaptic sites. Regulation of these various trafficking pathways has emerged as a key mechanism for activity-dependent plasticity of synaptic transmission, a process important for learning and memory. I here present my view of these findings. In particular, the advent of super-resolution microscopy and single-molecule tracking has helped to uncover the intricacy of AMPARs' dynamic organization at the nanoscale. In addition, AMPAR surface diffusion is highly regulated by a variety of factors, including neuronal activity, stress hormones, and neurodegeneration, suggesting that AMPAR diffusion-trapping may play a central role in synapse function. Using innovative tools to understand further the link between receptor dynamics and synapse plasticity is now unveiling new molecular mechanisms of learning. Modifying AMPAR dynamics may emerge as a new target to correct synapse dysfunction in the diseased brain.
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34
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Campbell BFN, Tyagarajan SK. Cellular Mechanisms Contributing to the Functional Heterogeneity of GABAergic Synapses. Front Mol Neurosci 2019; 12:187. [PMID: 31456660 PMCID: PMC6700328 DOI: 10.3389/fnmol.2019.00187] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 07/19/2019] [Indexed: 11/24/2022] Open
Abstract
GABAergic inhibitory neurotransmission contributes to diverse aspects of brain development and adult plasticity, including the expression of complex cognitive processes. This is afforded for in part by the dynamic adaptations occurring at inhibitory synapses, which show great heterogeneity both in terms of upstream signaling and downstream effector mechanisms. Single-particle tracking and live imaging have revealed that complex receptor-scaffold interactions critically determine adaptations at GABAergic synapses. Super-resolution imaging studies have shown that protein interactions at synaptic sites contribute to nano-scale scaffold re-arrangements through post-translational modifications (PTMs), facilitating receptor and scaffold recruitment to synaptic sites. Additionally, plasticity mechanisms may be affected by the protein composition at individual synapses and the type of pre-synaptic input. This mini-review article examines recent discoveries of plasticity mechanisms that are operational within GABAergic synapses and discusses their contribution towards functional heterogeneity in inhibitory neurotransmission.
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Affiliation(s)
| | - Shiva K Tyagarajan
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
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35
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Morton PE, Perrin C, Levitt J, Matthews DR, Marsh RJ, Pike R, McMillan D, Maloney A, Poland S, Ameer-Beg S, Parsons M. TNFR1 membrane reorganization promotes distinct modes of TNFα signaling. Sci Signal 2019; 12:eaaw2418. [PMID: 31363067 DOI: 10.1126/scisignal.aaw2418] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Signaling by the ubiquitously expressed tumor necrosis factor receptor 1 (TNFR1) after ligand binding plays an essential role in determining whether cells exhibit survival or death. TNFR1 forms distinct signaling complexes that initiate gene expression programs downstream of the transcriptional regulators NFκB and AP-1 and promote different functional outcomes, such as inflammation, apoptosis, and necroptosis. Here, we investigated the ways in which TNFR1 was organized at the plasma membrane at the nanoscale level to elicit different signaling outcomes. We confirmed that TNFR1 forms preassembled clusters at the plasma membrane of adherent cells in the absence of ligand. After trimeric TNFα binding, TNFR1 clusters underwent a conformational change, which promoted lateral mobility, their association with the kinase MEKK1, and activation of the JNK/p38/NFκB pathway. These phenotypes required a minimum of two TNFR1-TNFα contact sites; fewer binding sites resulted in activation of NFκB but not JNK and p38. These data suggest that distinct modes of TNFR1 signaling depend on nanoscale changes in receptor organization.
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Affiliation(s)
- Penny E Morton
- Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - Camille Perrin
- Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - James Levitt
- Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - Daniel R Matthews
- Nikon Imaging Centre, King's College London, Hodgkin Building, Guy's Campus, London SE1 1UL, UK
| | - Richard J Marsh
- Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - Rosemary Pike
- Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - David McMillan
- UCB Celltech, 208 Bath Road, Slough, Berkshire SL1 3WE, UK
| | - Alison Maloney
- UCB Celltech, 208 Bath Road, Slough, Berkshire SL1 3WE, UK
| | - Simon Poland
- Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
- School of Cancer and Pharmaceutical Sciences, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - Simon Ameer-Beg
- Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
- School of Cancer and Pharmaceutical Sciences, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | - Maddy Parsons
- Randall Centre for Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK.
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36
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Dupuis JP, Groc L. Surface trafficking of neurotransmitter receptors: From cultured neurons to intact brain preparations. Neuropharmacology 2019; 169:107642. [PMID: 31108111 DOI: 10.1016/j.neuropharm.2019.05.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 05/14/2019] [Accepted: 05/16/2019] [Indexed: 12/14/2022]
Abstract
Over the last decade, developments in single molecule imaging have changed our vision of synaptic physiology. By providing high spatio-temporal resolution maps of the molecular actors of neurotransmissions, these techniques have revealed that pre- and post-synaptic proteins are not randomly distributed but precisely organized at the nanoscale, and that this specific organization is dynamically regulated. At the centre of synaptic transmissions, neurotransmitter receptors have been shown to form nanodomains at synapses and to dynamically move in and out of these confinement areas through lateral diffusion within the membrane plane on millisecond timescales, thereby directly contributing to the regulation of synaptic transmission and plasticity. Since the vast majority of these discoveries originated from observations made on dissociated neurons lacking several features of brain tissue (e.g. three-dimensional organization, tissue density), they were initially considered with caution. However, the recent implementation of single-particle tracking (SPT) approaches in cultured and acute brain preparations confirmed that early findings on the dynamic properties of receptors at the surface of neurons can be extended to more physiological conditions. Taking example of dopamine D1 and NMDA glutamate receptors we here review our current knowledge of the features of neurotransmitter receptor surface diffusion in intact brain tissue. Through detailed comparison with cultured neurons, we also discuss how these biophysical properties are influenced by the complexity of the extracellular environment. This article is part of the special issue entitled 'Mobility and trafficking of neuronal membrane proteins'.
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Affiliation(s)
- Julien P Dupuis
- Université de Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000, Bordeaux, France; CNRS, IINS UMR 5297, 33000, Bordeaux, France
| | - Laurent Groc
- Université de Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000, Bordeaux, France; CNRS, IINS UMR 5297, 33000, Bordeaux, France.
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37
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Kim T, Tanaka-Yamamoto K. Postsynaptic Stability and Variability Described by a Stochastic Model of Endosomal Trafficking. Front Cell Neurosci 2019; 13:72. [PMID: 30863286 PMCID: PMC6399135 DOI: 10.3389/fncel.2019.00072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 02/13/2019] [Indexed: 12/04/2022] Open
Abstract
Neurons undergo dynamic processes of constitutive AMPA-type glutamate receptor (AMPAR) trafficking, such as the insertion and internalization of AMPARs by exocytosis and endocytosis, while stably maintaining synaptic efficacy. Studies using advanced imaging techniques have suggested that the frequency of these constitutive trafficking processes, as well as the number of AMPARs that are involved in a particular event highly fluctuate. In addition, mechanisms that trigger some forms of synaptic plasticity have been shown to include not only these processes but also additional fluctuating processes, such as the sorting of AMPARs to late endosomes (LEs). Thus, the regulation of postsynaptic AMPARs by the endosomal trafficking system appears to have superficially conflicting properties between the stability or organized control of plasticity and highly fluctuating or stochastic processes. However, it is not clear how the endosomal trafficking system reconciles and utilizes such conflicting properties. Although deterministic models have been effective to describe the stable maintenance of synaptic AMPAR numbers by constitutive recycling, as well as the involvement of endosomal trafficking in synaptic plasticity, they do not take stochasticity into account. In this study, we introduced the stochasticity into the model of each crucial machinery of the endosomal trafficking system. The specific questions we solved by our improved model are whether stability is accomplished even with a combination of fluctuating processes, and how overall variability occurs while controlling long-term synaptic depression (LTD). Our new stochastic model indeed demonstrated the stable regulation of postsynaptic AMPAR numbers at the basal state and during LTD maintenance, despite fast fluctuations in AMPAR numbers as well as high variability in the time course and amounts of LTD. In addition, our analysis suggested that the high variability arising from this stochasticity is beneficial for reproducing the relatively constant timing of LE sorting for LTD. We therefore propose that the coexistence of stability and stochasticity in the endosomal trafficking system is suitable for stable synaptic transmission and the reliable induction of synaptic plasticity, with variable properties that have been observed experimentally.
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Affiliation(s)
- Taegon Kim
- Center for Functional Connectomics, Korea Institute of Science and Technology (KIST), Seoul, South Korea
| | - Keiko Tanaka-Yamamoto
- Center for Functional Connectomics, Korea Institute of Science and Technology (KIST), Seoul, South Korea.,Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul, South Korea
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38
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Taylor BK, Sinha GP, Donahue RR, Grachen CM, Morón JA, Doolen S. Opioid receptors inhibit the spinal AMPA receptor Ca 2+ permeability that mediates latent pain sensitization. Exp Neurol 2019; 314:58-66. [PMID: 30660616 DOI: 10.1016/j.expneurol.2019.01.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 12/24/2018] [Accepted: 01/05/2019] [Indexed: 01/02/2023]
Abstract
Acute inflammation induces sensitization of nociceptive neurons and triggers the accumulation of calcium permeable (CP) α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs) in the dorsal horn of the spinal cord. This coincides with behavioral signs of acute inflammatory pain, but whether CP-AMPARs contribute to chronic pain remains unclear. To evaluate this question, we first constructed current-voltage (IV) curves of C-fiber stimulus-evoked, AMPAR-mediated EPSCs in lamina II to test for inward rectification, a key characteristic of CP-AMPARs. We found that the intraplantar injection of complete Freund's adjuvant (CFA) induced an inward rectification at 3 d that persisted to 21 d after injury. Furthermore, the CP- AMPAR antagonist IEM-1460 (50 μM) inhibited AMPAR-evoked Ca2+ transients 21d after injury but had no effect in uninflamed mice. We then used a model of long-lasting vulnerability for chronic pain that is determined by the balance between latent central sensitization (LCS) and mu opioid receptor constitutive activity (MORCA). When administered 21 d after the intraplantar injection of CFA, intrathecal administration of the MORCA inverse agonist naltrexone (NTX, 1 μg, i.t.) reinstated mechanical hypersensitivity, and superfusion of spinal cord slices with NTX (10 μM) increased the peak amplitude of AMPAR-evoked Ca2+ transients in lamina II neurons. The CP-AMPAR antagonist naspm (0-10 nmol, i.t.) inhibited these NTX-induced increases in mechanical hypersensitivity. NTX had no effect in uninflamed mice. Subsequent western blot analysis of the postsynaptic density membrane fraction from lumbar dorsal horn revealed that CFA increased GluA1 expression at 2 d and GluA4 expression at both 2 and 21 d post-injury, indicating that not just the GluA1 subunit, but also the GluA4 subunit, contributes to the expression of CP-AMPARs and synaptic strength during hyperalgesia. GluA2 expression increased at 21 d, an unexpected result that requires further study. We conclude that after tissue injury, dorsal horn AMPARs retain a Ca2+ permeability that underlies LCS. Because of their effectiveness in reducing naltrexone-induced reinstatement of hyperalgesia and potentiation of AMPAR-evoked Ca2+ signals, CP-AMPAR inhibitors are a promising class of agents for the treatment of chronic inflammatory pain.
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Affiliation(s)
- Bradley K Taylor
- Department of Anesthesiology, Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, 200 Lothrop St. Pittsburgh, PA 15213, USA; Department of Physiology, University of Kentucky School of Medicine, 800 Rose, St. Lexington, KY 40536-0298, USA.
| | - Ghanshyam P Sinha
- Department of Anesthesiology, Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, 200 Lothrop St. Pittsburgh, PA 15213, USA; Department of Physiology, University of Kentucky School of Medicine, 800 Rose, St. Lexington, KY 40536-0298, USA.
| | - Renee R Donahue
- Department of Physiology, University of Kentucky School of Medicine, 800 Rose, St. Lexington, KY 40536-0298, USA.
| | - Carolyn M Grachen
- Department of Anesthesiology, Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, 200 Lothrop St. Pittsburgh, PA 15213, USA; Department of Physiology, University of Kentucky School of Medicine, 800 Rose, St. Lexington, KY 40536-0298, USA.
| | - Jose A Morón
- Department of Anesthesiology, Washington University Pain Center, Washington University School of Medicine, 600 South Euclid, St Louis, MO 63110, USA.
| | - Suzanne Doolen
- Department of Anesthesiology, Pittsburgh Center for Pain Research, University of Pittsburgh School of Medicine, 200 Lothrop St. Pittsburgh, PA 15213, USA; Department of Physiology, University of Kentucky School of Medicine, 800 Rose, St. Lexington, KY 40536-0298, USA.
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39
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Coker HLE, Cheetham MR, Kattnig DR, Wang YJ, Garcia-Manyes S, Wallace MI. Controlling Anomalous Diffusion in Lipid Membranes. Biophys J 2019; 116:1085-1094. [PMID: 30846364 DOI: 10.1016/j.bpj.2018.12.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 11/21/2018] [Accepted: 12/14/2018] [Indexed: 12/24/2022] Open
Abstract
Diffusion in cell membranes is not just simple two-dimensional Brownian motion but typically depends on the timescale of the observation. The physical origins of this anomalous subdiffusion are unresolved, and model systems capable of quantitative and reproducible control of membrane diffusion have been recognized as a key experimental bottleneck. Here, we control anomalous diffusion using supported lipid bilayers containing lipids derivatized with polyethylene glycol (PEG) headgroups. Bilayers with specific excluded area fractions are formed by control of PEG lipid mole fraction. These bilayers exhibit a switch in diffusive behavior, becoming anomalous as bilayer continuity is disrupted. Using a combination of single-molecule fluorescence and interferometric imaging, we measure the anomalous behavior in this model over four orders of magnitude in time. Diffusion in these bilayers is well described by a power-law dependence of the mean-square displacement with observation time. Anomaleity in this system can be tailored by simply controlling the mole fraction of PEG lipid, producing bilayers with diffusion parameters similar to those observed for anomalous diffusion in biological membranes.
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Affiliation(s)
- Helena L E Coker
- Department of Chemistry, King's College London, London, United Kingdom; Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Matthew R Cheetham
- Department of Chemistry, King's College London, London, United Kingdom; Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Daniel R Kattnig
- Living Systems Institute & Department of Physics, University of Exeter, Exeter, United Kingdom
| | - Yong J Wang
- Department of Physics, King's College London, London, United Kingdom
| | | | - Mark I Wallace
- Department of Chemistry, King's College London, London, United Kingdom.
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40
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Thal LB, Tomlinson ID, Quinlan MA, Kovtun O, Blakely RD, Rosenthal SJ. Single Quantum Dot Imaging Reveals PKCβ-Dependent Alterations in Membrane Diffusion and Clustering of an Attention-Deficit Hyperactivity Disorder/Autism/Bipolar Disorder-Associated Dopamine Transporter Variant. ACS Chem Neurosci 2019; 10:460-471. [PMID: 30153408 PMCID: PMC6411462 DOI: 10.1021/acschemneuro.8b00350] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The dopamine transporter (DAT) is a transmembrane protein that terminates dopamine signaling in the brain by driving rapid dopamine reuptake into presynaptic nerve terminals. Several lines of evidence indicate that DAT dysfunction is linked to neuropsychiatric disorders such as attention-deficit/hyperactivity disorder (ADHD), bipolar disorder (BPD), and autism spectrum disorder (ASD). Indeed, individuals with these disorders have been found to express the rare, functional DAT coding variant Val559, which confers anomalous dopamine efflux (ADE) in vitro and in vivo. To elucidate the impact of the DAT Val559 variant on membrane diffusion dynamics, we implemented our antagonist-conjugated quantum dot (QD) labeling approach to monitor the lateral mobility of single particle-labeled transporters in transfected HEK-293 and SK-N-MC cells. Our results demonstrate significantly higher diffusion coefficients of DAT Val559 compared to those of DAT Ala559, effects likely determined by elevated N-terminal transporter phosphorylation. We also provide pharmacological evidence that PKCβ-mediated signaling supports enhanced DAT Val559 membrane diffusion rates. Additionally, our results are complimented with diffusion rates of phosphomimicked and phosphorylation-occluded DAT variants. Furthermore, we show DAT Val559 has a lower propensity for membrane clustering, which may be caused by a mutation-derived shift out of membrane microdomains leading to faster lateral membrane diffusion rates. These findings further demonstrate a functional impact of DAT Val559 and suggest that changes in transporter localization and lateral mobility may sustain ADE and contribute to alterations in dopamine signaling underlying multiple neuropsychiatric disorders.
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41
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Hrabetova S, Cognet L, Rusakov DA, Nägerl UV. Unveiling the Extracellular Space of the Brain: From Super-resolved Microstructure to In Vivo Function. J Neurosci 2018; 38:9355-9363. [PMID: 30381427 PMCID: PMC6706003 DOI: 10.1523/jneurosci.1664-18.2018] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 09/25/2018] [Accepted: 09/26/2018] [Indexed: 11/21/2022] Open
Abstract
The extracellular space occupies approximately one-fifth of brain volume, molding a spider web of gaps filled with interstitial fluid and extracellular matrix where neurons and glial cells perform in concert. Yet, very little is known about the spatial organization and dynamics of the extracellular space, let alone its influence on brain function, owing to a lack of appropriate techniques (and a traditional bias toward the inside of cells, not the spaces in between). At the same time, it is clear that understanding fundamental brain functions, such as synaptic transmission, memory, sleep, and recovery from disease, calls for more focused research on the extracellular space of the brain. This review article highlights several key research areas, covering recent methodological and conceptual progress that illuminates this understudied, yet critically important, brain compartment, providing insights into the opportunities and challenges of this nascent field.
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Affiliation(s)
- Sabina Hrabetova
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, New York 11203
| | - Laurent Cognet
- Université de Bordeaux, Laboratoire Photonique Numérique et Nanosciences, F-33400 Talence, France
- Institut d'Optique and Centre National de la Recherche Scientifique, F-33400 Talence, France
| | - Dmitri A Rusakov
- Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
| | - U Valentin Nägerl
- Institut Interdisciplinaire des Neurosciences, Université de Bordeaux, 33077 Bordeaux, France, and
- Institut Interdisciplinaire des Neurosciences, Centre National de la Recherche, 33077 Bordeaux, France
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42
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Weatherill EE, Coker HLE, Cheetham MR, Wallace MI. Urea-mediated anomalous diffusion in supported lipid bilayers. Interface Focus 2018; 8:20180028. [PMID: 30443327 PMCID: PMC6227775 DOI: 10.1098/rsfs.2018.0028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2018] [Indexed: 12/16/2022] Open
Abstract
Diffusion in biological membranes is seldom simply Brownian motion; instead, the rate of diffusion is dependent on the time scale of observation and so is often described as anomalous. In order to help better understand this phenomenon, model systems are needed where the anomalous diffusion of the lipid bilayer can be tuned and quantified. We recently demonstrated one such model by controlling the excluded area fraction in supported lipid bilayers (SLBs) through the incorporation of lipids derivatized with polyethylene glycol. Here, we extend this work, using urea to induce anomalous diffusion in SLBs. By tuning incubation time and urea concentration, we produce bilayers that exhibit anomalous behaviour on the same scale as that observed in biological membranes.
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Affiliation(s)
- E. E. Weatherill
- Department of Chemistry, Britannia House, King's College London, 7 Trinity Street, London SE1 1DB, UK
| | - H. L. E. Coker
- Department of Chemistry, Britannia House, King's College London, 7 Trinity Street, London SE1 1DB, UK
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
| | - M. R. Cheetham
- Department of Chemistry, Britannia House, King's College London, 7 Trinity Street, London SE1 1DB, UK
- Cavendish Laboratory, Department of Physics, NanoPhotonics Centre, University of Cambridge, Cambridge CB3 0HE, UK
| | - M. I. Wallace
- Department of Chemistry, Britannia House, King's College London, 7 Trinity Street, London SE1 1DB, UK
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43
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Goo BMSS, Sanstrum BJ, Holden DZY, Yu Y, James NG. Arc/Arg3.1 has an activity-regulated interaction with PICK1 that results in altered spatial dynamics. Sci Rep 2018; 8:14675. [PMID: 30279480 PMCID: PMC6168463 DOI: 10.1038/s41598-018-32821-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 05/25/2018] [Indexed: 01/28/2023] Open
Abstract
Activity-regulated cytoskeleton-associated protein (Arc; also known as Arg3.1) is an immediate early gene product that is transcribed in dendritic spines and, to date, has been best characterized as a positive regulator of AMPAR endocytosis during long-term depression (LTD) through interaction with endocytic proteins. Here, we show that protein interacting with C terminal kinase 1 (PICK1), a protein known to bind to the GluA2 subunit of AMPARs and associated with AMPAR trafficking, was pulled-down from brain homogenates and synaptosomes when using Arc as immobilized bait. Fluctuation and FLIM-FRET-Phasor analysis revealed direct interaction between these proteins when co-expressed that was increased under depolarizing conditions in live cells. At the plasma membrane, Arc-mCherry oligomerization was found to be concentration dependent. Additionally, co-expression of Arc-mCherry and EGFP-PICK1 followed by depolarizing conditions resulted in significant increases in the number and size of puncta containing both proteins. Furthermore, we identified the Arc binding region to be the first 126 amino acids of the PICK1 BAR domain. Overall, our data support a novel interaction and model where PICK1 mediates Arc regulation of AMPARs particularly under depolarizing conditions.
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Affiliation(s)
- Brandee M S S Goo
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, 651 Ilalo St., BSB 222, University of Hawaii, Honolulu, HI, 96813, USA
| | - Bethany J Sanstrum
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, 651 Ilalo St., BSB 222, University of Hawaii, Honolulu, HI, 96813, USA
| | - Diana Z Y Holden
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, 651 Ilalo St., BSB 222, University of Hawaii, Honolulu, HI, 96813, USA
| | | | - Nicholas G James
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, 651 Ilalo St., BSB 222, University of Hawaii, Honolulu, HI, 96813, USA.
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44
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Berthoux C, Barre A, Bockaert J, Marin P, Bécamel C. Sustained Activation of Postsynaptic 5-HT2A Receptors Gates Plasticity at Prefrontal Cortex Synapses. Cereb Cortex 2018; 29:1659-1669. [DOI: 10.1093/cercor/bhy064] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 02/26/2018] [Indexed: 01/01/2023] Open
Affiliation(s)
- Coralie Berthoux
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université de Montpellier, Montpellier, France
| | - Alexander Barre
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université de Montpellier, Montpellier, France
| | - Joël Bockaert
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université de Montpellier, Montpellier, France
| | - Philippe Marin
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université de Montpellier, Montpellier, France
| | - Carine Bécamel
- Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Université de Montpellier, Montpellier, France
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45
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Borroto-Escuela DO, Tarakanov AO, Brito I, Fuxe K. Glutamate heteroreceptor complexes in the brain. Pharmacol Rep 2018; 70:936-950. [PMID: 32002960 DOI: 10.1016/j.pharep.2018.04.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 03/26/2018] [Accepted: 04/09/2018] [Indexed: 10/17/2022]
Abstract
The existence of mGluR, NMDAR, AMPAR and putative KAR heteroreceptor complexes in synaptic and extrasynaptic regions of brain glutamate synapses represents a major integrative mechanism. Our aim in the current article is to analyze if the formation of the different types glutamate hetereceptor complexes involves the contribution of triplet amino acid homologies (protriplets) in a postulated receptor interface based on the triplet puzzle theory. Seven main sets (lists) of receptor pairs in databases were used containing various sets (lists) of human receptor heteromers and nonheteromers obtained from the available scientific publications including the publically available GPCR-hetnet database. Brain mGluR1-mGluR5 and mGluR2-mGluR4 isoreceptor complexes were demonstrated with a predominant extrasynaptic localization at a post- and prejunctional localization. The existence of putative mGluR4-mGluR7 heteroreceptor complexes in the basal ganglia is proposed. Metabotropic glutamate receptor subtypes also participated in the formation of a large number of heteroreceptor complexes like mGluR1-A1R, mGluR5-A2AR, mGluR5-D2R and D2R-A2AR-mGluR5, located in relation to glutamate synapses, especially in the basal ganglia. A putative mGluR1-GABAB1/2 heterocomplex may also exist. NMDAR heteroreceptor complexes were also demonstrated as a fundamental integrative mechanism in the glutamate synapse and its extrasynaptic membranes. It represented fundamental work on inter alia NMDAR-mGluR5, NMDAR-D1R and NMDAR-D2R heteroreceptor complexes involving both antagonistic and facilitatory allosteric receptor-receptor interactions. As to AMPA receptors, a heterocomplex was found for the interaction between IFNgR1 and the AMPAR mediated via the subunit GluA1 which may be of relevance for neuroinflammation. AMPAR-D2R heteroreceptor complexes were also demonstrated. Besides glutamate heteroreceptor complexes and their allosteric receptor-receptor interactions, a significant mechanism for the functional crosstalk can also be phosphorylation and/or reorganization of adapter proteins with dynamic binding to the two receptors modulating the allosteric receptor mechanism.
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Affiliation(s)
- Dasiel O Borroto-Escuela
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Biomolecular Science, Section of Physiology, University of Urbino, Campus Scientifico Enrico Mattei, Urbino, Italy.,Grupo Bohío-Estudio, Observatorio Cubano de Neurociencias, Yaguajay, Cuba
| | - Alexander O Tarakanov
- St. Petersburg Institute for Informatics and Automation, Russian Academy of Sciences, Saint Petersburg, Russia
| | - Ismel Brito
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Grupo Bohío-Estudio, Observatorio Cubano de Neurociencias, Yaguajay, Cuba
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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46
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Sequences Flanking the Gephyrin-Binding Site of GlyRβ Tune Receptor Stabilization at Synapses. eNeuro 2018; 5:eN-NWR-0042-17. [PMID: 29464196 PMCID: PMC5818551 DOI: 10.1523/eneuro.0042-17.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 12/26/2017] [Accepted: 01/15/2018] [Indexed: 12/18/2022] Open
Abstract
The efficacy of synaptic transmission is determined by the number of neurotransmitter receptors at synapses. Their recruitment depends upon the availability of postsynaptic scaffolding molecules that interact with specific binding sequences of the receptor. At inhibitory synapses, gephyrin is the major scaffold protein that mediates the accumulation of heteromeric glycine receptors (GlyRs) via the cytoplasmic loop in the β-subunit (β-loop). This binding involves high- and low-affinity interactions, but the molecular mechanism of this bimodal binding and its implication in GlyR stabilization at synapses remain unknown. We have approached this question using a combination of quantitative biochemical tools and high-density single molecule tracking in cultured rat spinal cord neurons. The high-affinity binding site could be identified and was shown to rely on the formation of a 310-helix C-terminal to the β-loop core gephyrin-binding motif. This site plays a structural role in shaping the core motif and represents the major contributor to the synaptic confinement of GlyRs by gephyrin. The N-terminal flanking sequence promotes lower affinity interactions by occupying newly identified binding sites on gephyrin. Despite its low affinity, this binding site plays a modulatory role in tuning the mobility of the receptor. Together, the GlyR β-loop sequences flanking the core-binding site differentially regulate the affinity of the receptor for gephyrin and its trapping at synapses. Our experimental approach thus bridges the gap between thermodynamic aspects of receptor-scaffold interactions and functional receptor stabilization at synapses in living cells.
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47
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Schmitz LJM, Klaassen RV, Ruiperez-Alonso M, Zamri AE, Stroeder J, Rao-Ruiz P, Lodder JC, van der Loo RJ, Mansvelder HD, Smit AB, Spijker S. The AMPA receptor-associated protein Shisa7 regulates hippocampal synaptic function and contextual memory. eLife 2017; 6:24192. [PMID: 29199957 PMCID: PMC5737659 DOI: 10.7554/elife.24192] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 12/02/2017] [Indexed: 12/20/2022] Open
Abstract
Glutamatergic synapses rely on AMPA receptors (AMPARs) for fast synaptic transmission and plasticity. AMPAR auxiliary proteins regulate receptor trafficking, and modulate receptor mobility and its biophysical properties. The AMPAR auxiliary protein Shisa7 (CKAMP59) has been shown to interact with AMPARs in artificial expression systems, but it is unknown whether Shisa7 has a functional role in glutamatergic synapses. We show that Shisa7 physically interacts with synaptic AMPARs in mouse hippocampus. Shisa7 gene deletion resulted in faster AMPAR currents in CA1 synapses, without affecting its synaptic expression. Shisa7 KO mice showed reduced initiation and maintenance of long-term potentiation of glutamatergic synapses. In line with this, Shisa7 KO mice showed a specific deficit in contextual fear memory, both short-term and long-term after conditioning, whereas auditory fear memory and anxiety-related behavior were normal. Thus, Shisa7 is a bona-fide AMPAR modulatory protein affecting channel kinetics of AMPARs, necessary for synaptic hippocampal plasticity, and memory recall.
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Affiliation(s)
- Leanne J M Schmitz
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands.,Sylics (Synaptologics BV), Amsterdam, The Netherlands
| | - Remco V Klaassen
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
| | - Marta Ruiperez-Alonso
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Azra Elia Zamri
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands.,Université de Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, Bordeaux, France
| | - Jasper Stroeder
- Sylics (Synaptologics BV), Amsterdam, The Netherlands.,Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Priyanka Rao-Ruiz
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
| | - Johannes C Lodder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Rolinka J van der Loo
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands.,Sylics (Synaptologics BV), Amsterdam, The Netherlands
| | - Huib D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
| | - Sabine Spijker
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, Amsterdam, The Netherlands
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48
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Heller JP, Rusakov DA. The Nanoworld of the Tripartite Synapse: Insights from Super-Resolution Microscopy. Front Cell Neurosci 2017; 11:374. [PMID: 29225567 PMCID: PMC5705901 DOI: 10.3389/fncel.2017.00374] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 11/10/2017] [Indexed: 12/17/2022] Open
Abstract
Synaptic connections between individual nerve cells are fundamental to the process of information transfer and storage in the brain. Over the past decades a third key partner of the synaptic machinery has been unveiled: ultrathin processes of electrically passive astroglia which often surround pre- and postsynaptic structures. The recent advent of super-resolution (SR) microscopy has begun to uncover the dynamic nanoworld of synapses and their astroglial environment. Here we overview and discuss the current progress in our understanding of the synaptic nanoenvironment, as gleaned from the imaging methods that go beyond the diffraction limit of conventional light microscopy. We argue that such methods are essential to achieve a new level of comprehension pertinent to the principles of signal integration in the brain.
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Affiliation(s)
- Janosch P Heller
- UCL Institute of Neurology, University College London, London, United Kingdom
| | - Dmitri A Rusakov
- UCL Institute of Neurology, University College London, London, United Kingdom.,Institute of Neuroscience, University of Nizhny Novgorod, Nizhny Novgorod, Russia
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49
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Abstract
The emerging technological revolution in genetically encoded molecular sensors and super-resolution imaging provides neuroscientists with a pass to the real-time nano-world. On this small scale, however, classical principles of electrophysiology do not always apply. This is in large part because the nanoscopic heterogeneities in ionic concentrations and the local electric fields associated with individual ions and their movement can no longer be ignored. Here, we review basic principles of molecular electrodiffusion in the cellular environment of organized brain tissue. We argue that accurate interpretation of physiological observations on the nanoscale requires a better understanding of the underlying electrodiffusion phenomena.
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50
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Han B, Fang Y, Feng M, Hu H, Hao Y, Ma C, Huo X, Meng L, Zhang X, Wu F, Li J. Brain Membrane Proteome and Phosphoproteome Reveal Molecular Basis Associating with Nursing and Foraging Behaviors of Honeybee Workers. J Proteome Res 2017; 16:3646-3663. [DOI: 10.1021/acs.jproteome.7b00371] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Bin Han
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Yu Fang
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Mao Feng
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Han Hu
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Yue Hao
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Chuan Ma
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Xinmei Huo
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Lifeng Meng
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Xufeng Zhang
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Fan Wu
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Jianke Li
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
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