151
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Zhang W, Wu Q, Lu YL, Gong QH, Zhang F, Shi JS. Protective effects of Dendrobium nobile Lindl. alkaloids on amyloid beta (25-35)-induced neuronal injury. Neural Regen Res 2017; 12:1131-1136. [PMID: 28852396 PMCID: PMC5558493 DOI: 10.4103/1673-5374.211193] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Dendrobium nobile Lindl. alkaloids (DNLA), the active ingredients of a traditional Chinese medicine Dendrobium, have been shown to have anti-oxidative effects, anti-inflammatory action, and protective effect on neurons against oxygen-glucose deprivation. However, it is not clear whether DNLA reduces amyloid-beta (Aβ)-induced neuronal injury. In this study, cortical neurons were treated with DNLA at different concentrations (0.025, 0.25, and 2.5 mg/L) for 24 hours, followed by administration of Aβ25-35 (10 μM). Aβ25-35 treatments increased cell injury as determined by the leakage of lactate dehydrogenase, which was accompanied by chromatin condensation and mitochondrial tumefaction. The damage caused by Aβ25-35 on these cellular properties was markedly attenuated when cells were pretreated with DNLA. Treatment with Aβ25-35 down-regulated the expressions of postsynaptic density-95 mRNA and decreased the protein expression of synaptophysin and postsynaptic density-95, all changes were significantly reduced by pretreatment of cells with DNLA. These findings suggest that DNLA reduces the cytotoxicity induced by Aβ25-35 in rat primary cultured neurons. The protective mechanism that DNLA confers on the synaptic integrity of cultured neurons might be mediated, at least in part, through the upregulation of neurogenesis related proteins synaptophysin and postsynaptic density-95.
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Affiliation(s)
- Wei Zhang
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou Province, China
| | - Qin Wu
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou Province, China
| | - Yan-Liu Lu
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou Province, China
| | - Qi-Hai Gong
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou Province, China
| | - Feng Zhang
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou Province, China
| | - Jing-Shan Shi
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou Province, China
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152
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Ke C, Gao F, Tian X, Li C, Shi D, He W, Tian Y. Slit2/Robo1 Mediation of Synaptic Plasticity Contributes to Bone Cancer Pain. Mol Neurobiol 2017; 54:295-307. [PMID: 26738857 DOI: 10.1007/s12035-015-9564-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/29/2015] [Indexed: 12/11/2022]
Abstract
Synaptic plasticity is fundamental to spinal sensitivity of bone cancer pain. Here, we have shown that excitatory synaptogenesis contributes to bone cancer pain. New synapse formation requires neurite outgrowth and an interaction between axons and dendrites, accompanied by the appositional organization of presynaptic and postsynaptic specializations. We have shown that Slit2, Robo1, and RhoA act as such cues that promote neurite outgrowth and guide the axon for synapse formation. Sarcoma inoculation induces excitatory synaptogenesis and bone cancer pain which are reversed by Slit2 knockdown but aggravated by Robo1 knockdown. Synaptogenesis of cultured neurons are inhibited by Slit2 knockdown but enhanced by Robo1 knockdown. Sarcoma implantation induces an increase in Slit2 and decreases Robo1 and RhoA, while Slit2 knockdown results in an increase of Robo1 and RhoA. These results have demonstrated a molecular mechanism of synaptogenesis in bone cancer pain.
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Affiliation(s)
- Changbin Ke
- Institute of Anesthesiology and Pain (IAP) and Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan City, 442000, Hubei Province, China
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Feng Gao
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xuebi Tian
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Caijuan Li
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Dai Shi
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Wensheng He
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yuke Tian
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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153
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Imig C, Cooper BH. 3D Analysis of Synaptic Ultrastructure in Organotypic Hippocampal Slice Culture by High-Pressure Freezing and Electron Tomography. Methods Mol Biol 2017; 1538:215-231. [PMID: 27943193 DOI: 10.1007/978-1-4939-6688-2_15] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Transmission electron microscopy serves as a valuable tool for synaptic structure-function analyses aimed at identifying morphological features or modifications associated with specific developmental stages or dysfunctional synaptic states. By utilizing cryo-preparation techniques to minimize the introduction of structural artifacts during sample preparation, and electron tomography to reconstruct the 3D ultrastructural architecture of a synapse, the spatial organization and morphological properties of synaptic organelles and subcompartments can be quantified with unparalleled precision. In this chapter, we present an experimental approach combining organotypic slice culture, high-pressure freezing, automated freeze-substitution, and electron tomography to investigate spatial relationships between synaptic vesicles and active zone release sites in synapses from lethal mouse mutants.
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Affiliation(s)
- Cordelia Imig
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075, Göttingen, Germany
| | - Benjamin H Cooper
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075, Göttingen, Germany.
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154
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Palmitoylation regulates glutamate receptor distributions in postsynaptic densities through control of PSD95 conformation and orientation. Proc Natl Acad Sci U S A 2016; 113:E8482-E8491. [PMID: 27956638 DOI: 10.1073/pnas.1612963113] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Postsynaptic density protein 95 (PSD95) and synapse-associated protein 97 (SAP97) are homologous scaffold proteins with different N-terminal domains, possessing either a palmitoylation site (PSD95) or an L27 domain (SAP97). Here, we measured PSD95 and SAP97 conformation in vitro and in postsynaptic densities (PSDs) using FRET and EM, and examined how conformation regulated interactions with AMPA-type and NMDA-type glutamate receptors (AMPARs/NMDARs). Palmitoylation of PSD95 changed its conformation from a compact to an extended configuration. PSD95 associated with AMPARs (via transmembrane AMPAR regulatory protein subunits) or NMDARs [via glutamate ionotropic receptor NMDA-type subunit 2B (GluN2B) subunits] only in its palmitoylated and extended conformation. In contrast, in its extended conformation, SAP97 associates with NMDARs, but not with AMPARs. Within PSDs, PSD95 and SAP97 were largely in the extended conformation, but had different orientations. PSD95 oriented perpendicular to the PSD membrane, with its palmitoylated, N-terminal domain at the membrane. SAP97 oriented parallel to the PSD membrane, likely as a dimer through interactions of its N-terminal L27 domain. Changing PSD95 palmitoylation in PSDs altered PSD95 and AMPAR levels but did not affect NMDAR levels. These results indicate that in PSDs, PSD95 palmitoylation, conformation, and its interactions are dynamic when associated with AMPARs and more stable when associated with NMDARs. Altogether, our results are consistent with differential regulation of PSD95 palmitoylation in PSDs resulting from the clustering of palmitoylating and depalmitoylating enzymes into AMPAR nanodomains segregated away from NMDAR nanodomains.
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155
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Protein Crowding within the Postsynaptic Density Can Impede the Escape of Membrane Proteins. J Neurosci 2016; 36:4276-95. [PMID: 27076425 DOI: 10.1523/jneurosci.3154-15.2016] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 02/19/2016] [Indexed: 01/03/2023] Open
Abstract
UNLABELLED Mechanisms regulating lateral diffusion and positioning of glutamate receptors within the postsynaptic density (PSD) determine excitatory synaptic strength. Scaffold proteins in the PSD are abundant receptor binding partners, yet electron microscopy suggests that the PSD is highly crowded, potentially restricting the diffusion of receptors regardless of binding. However, the contribution of macromolecular crowding to receptor retention remains poorly understood. We combined experimental and computational approaches to test the effect of synaptic crowding on receptor movement and positioning in Sprague Dawley rat hippocampal neurons. We modeled AMPA receptor diffusion in synapses where the distribution of scaffold proteins was determined from photoactivated localization microscopy experiments, and receptor-scaffold association and dissociation rates were adjusted to fit single-molecule tracking and fluorescence recovery measurements. Simulations predicted that variation of receptor size strongly influences the fractional synaptic area the receptor may traverse, and the proportion that may exchange in and out of the synapse. To test the model experimentally, we designed a set of novel transmembrane (TM) probes. A single-pass TM protein with one PDZ binding motif concentrated in the synapse as do AMPARs yet was more mobile there than the much larger AMPAR. Furthermore, either the single binding motif or an increase in cytoplasmic bulk through addition of a single GFP slowed synaptic movement of a small TM protein. These results suggest that both crowding and binding limit escape of AMPARs from the synapse. Moreover, tight protein packing within the PSD may modulate the synaptic dwell time of many TM proteins important for synaptic function. SIGNIFICANCE STATEMENT Small alterations to the distribution within synapses of key transmembrane proteins, such as receptors, can dramatically change synaptic strength. Indeed, many diseases are thought to unbalance neural circuit function in this manner. Processes that regulate this in healthy synapses are unclear, however. By combining computer simulations with imaging methods that examined protein dynamics at multiple scales in space and time, we showed that both steric effects and protein-protein binding each regulate the mobility of receptors in the synapse. Our findings extend our knowledge of the synapse as a crowded environment that counteracts molecular diffusion, and support the idea that both molecular collisions and biochemical binding can be involved in the regulation of neural circuit performance.
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156
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Keller B, García-Sevilla JA. Inhibitory effects of imidazoline receptor ligands on basal and kainic acid-induced neurotoxic signalling in mice. J Psychopharmacol 2016; 30:875-86. [PMID: 27302941 DOI: 10.1177/0269881116652579] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This in vivo study assessed the potential of the imidazoline receptor (IR) ligands moxonidine (selective I1-IR), BU224 (selective I2-IR) and LSL61122 (mixed I1/I2-IR) to dampen excitotoxic signalling induced by kainic acid (KA; 45 mg/kg) in the mouse brain (hippocampus and cerebral cortex). KA triggered a strong behavioural syndrome (seizures; maximal at 60-90 minutes) and sustained stimulation (at 72 hours with otherwise normal mouse behaviour) of pro-apoptotic c-Jun-N-terminal kinases (JNK) and calpain with increased cleavage of p35 into neurotoxic p25 (cyclin-dependent kinase 5 [Cdk5] activators) in mouse hippocampus. Pretreatment (five days) with LSL61122 (10 mg/kg), but not moxonidine (1 mg/kg) or BU224 (20 mg/kg), attenuated the KA-induced behavioural syndrome, and all three IR ligands inhibited JNK and calpain activation, as well as p35/p25 cleavage after KA in the hippocampus (effects also observed after acute IR drug treatments). Efaroxan (I1-IR, 10 mg/kg) and idazoxan (I2-IR, 10 mg/kg), postulated IR antagonists, did not antagonise the effects of moxonidine and LSL61122 on KA targets (these IR ligands showed agonistic properties inhibiting pro-apoptotic JNK). Brain subcellular preparations revealed reduced synaptosomal postsynaptic density-95 protein contents (a mediator of JNK activation) and indicated increased p35/Cdk5 complexes (with pro-survival functions) after treatment with moxonidine, BU224 and LSL61122. These results showed that I1- and I2-IR ligands (moxonidine and BU224), and especially the mixed I1/I2-IR ligand LSL61122, are partly neuroprotective against KA-induced excitotoxic signalling. These findings suggest a therapeutic potential of IR drugs in disorders associated with glutamate-mediated neurodegeneration.
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Affiliation(s)
- Benjamin Keller
- Laboratory of Neuropharmacology, IUNICS-IdISPa, University of the Balearic Islands (UIB), Palma de Mallorca, Spain Redes Temáticas de Investigación Cooperativa en Salud-Red de Trastornos Adictivos (RETICS-RTA), ISCIII, Madrid, Spain
| | - Jesús A García-Sevilla
- Laboratory of Neuropharmacology, IUNICS-IdISPa, University of the Balearic Islands (UIB), Palma de Mallorca, Spain Redes Temáticas de Investigación Cooperativa en Salud-Red de Trastornos Adictivos (RETICS-RTA), ISCIII, Madrid, Spain
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157
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Zhan H, Bruckner J, Zhang Z, O’Connor-Giles K. Three-dimensional imaging of Drosophila motor synapses reveals ultrastructural organizational patterns. J Neurogenet 2016; 30:237-246. [PMID: 27981875 PMCID: PMC5281062 DOI: 10.1080/01677063.2016.1253693] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 10/22/2016] [Accepted: 10/24/2016] [Indexed: 01/18/2023]
Abstract
We combined cryo-preservation of intact Drosophila larvae and electron tomography with comprehensive segmentation of key features to reconstruct the complete ultrastructure of a model glutamatergic synapse in a near-to-native state. Presynaptically, we detail a complex network of filaments that connects and organizes synaptic vesicles. We link the complexity of this synaptic vesicle network to proximity to the active zone cytomatrix, consistent with the model that these protein structures function together to regulate synaptic vesicle pools. We identify a net-shaped network of electron-dense filaments spanning the synaptic cleft that suggests conserved organization of trans-synaptic adhesion complexes at excitatory synapses. Postsynaptically, we characterize a regular pattern of macromolecules that yields structural insights into the scaffolding of neurotransmitter receptors. Together, these analyses reveal an unexpected level of conservation in the nanoscale organization of diverse glutamatergic synapses and provide a structural foundation for understanding the molecular machines that regulate synaptic communication at a powerful model synapse.
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Affiliation(s)
- Hong Zhan
- Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706
| | - Joseph Bruckner
- Cell and Molecular Biology Training Program, University of Wisconsin-Madison, Madison, WI 53706
| | - Ziheng Zhang
- Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706
| | - Kate O’Connor-Giles
- Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI 53706
- Cell and Molecular Biology Training Program, University of Wisconsin-Madison, Madison, WI 53706
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706
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158
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Dosemeci A, Weinberg RJ, Reese TS, Tao-Cheng JH. The Postsynaptic Density: There Is More than Meets the Eye. Front Synaptic Neurosci 2016; 8:23. [PMID: 27594834 PMCID: PMC4990544 DOI: 10.3389/fnsyn.2016.00023] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 07/25/2016] [Indexed: 11/28/2022] Open
Abstract
The postsynaptic density (PSD), apparent in electron micrographs as a dense lamina just beneath the postsynaptic membrane, includes a deeper layer, the “pallium”, containing a scaffold of Shank and Homer proteins. Though poorly defined in traditionally prepared thin-section electron micrographs, the pallium becomes denser and more conspicuous during intense synaptic activity, due to the reversible addition of CaMKII and other proteins. In this Perspective article, we review the significance of CaMKII-mediated recruitment of proteins to the pallium with respect to both the trafficking of receptors and the remodeling of spine shape that follow synaptic stimulation. We suggest that the level and duration of CaMKII translocation and activation in the pallium will shape activity-induced changes in the spine.
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Affiliation(s)
- Ayse Dosemeci
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH) Bethesda, MD, USA
| | - Richard J Weinberg
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill Chapel Hill, NC, USA
| | - Thomas S Reese
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH) Bethesda, MD, USA
| | - Jung-Hwa Tao-Cheng
- Electron Microscopy Facility, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH) Bethesda, MD, USA
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159
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A Network of Three Types of Filaments Organizes Synaptic Vesicles for Storage, Mobilization, and Docking. J Neurosci 2016; 36:3222-30. [PMID: 26985032 DOI: 10.1523/jneurosci.2939-15.2016] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED Synaptic transmission between neurons requires precise management of synaptic vesicles. While individual molecular components of the presynaptic terminal are well known, exactly how the molecules are organized into a molecular machine serving the storage and mobilization of synaptic vesicles to the active zone remains unclear. Here we report three filament types associated with synaptic vesicles in glutamatergic synapses revealed by electron microscope tomography in unstimulated, dissociated rat hippocampal neurons. One filament type, likely corresponding to the SNAREpin complex, extends from the active zone membrane and surrounds docked vesicles. A second filament type contacts all vesicles throughout the active zone and pairs vesicles together. On the third filament type, vesicles attach to side branches extending from the long filament core and form vesicle clusters that are distributed throughout the vesicle cloud and along the active zone membrane. Detailed analysis of presynaptic structure reveals how each of the three filament types interacts with synaptic vesicles, providing a means to traffic reserved and recycled vesicles from the cloud of vesicles into the docking position at the active zone. SIGNIFICANCE STATEMENT The formation and release of synaptic vesicles has been extensively investigated. Explanations of the release of synaptic vesicles generally begin with the movement of vesicles from the cloud into the synaptic active zone. However, the presynaptic terminal is filled with filamentous material that would appear to limit vesicular diffusion. Here, we provide a systematic description of three filament types connecting synaptic vesicles. A picture emerges illustrating how the cooperative attachment and release of these three filament types facilitate the movement of vesicles to the active zone to become docked in preparation for release.
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160
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Negative regulation of microRNA-132 in expression of synaptic proteins in neuronal differentiation of embryonic neural stem cells. Neurochem Int 2016; 97:26-33. [DOI: 10.1016/j.neuint.2016.04.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 04/07/2016] [Accepted: 04/26/2016] [Indexed: 02/06/2023]
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161
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Molecular evidence of synaptic pathology in the CA1 region in schizophrenia. NPJ SCHIZOPHRENIA 2016; 2:16022. [PMID: 27430010 PMCID: PMC4944906 DOI: 10.1038/npjschz.2016.22] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 05/21/2016] [Accepted: 05/23/2016] [Indexed: 11/09/2022]
Abstract
Alterations of postsynaptic density (PSD)95-complex proteins in schizophrenia ostensibly induce deficits in synaptic plasticity, the molecular process underlying cognitive functions. Although some PSD95-complex proteins have been previously examined in the hippocampus in schizophrenia, the status of other equally important molecules is unclear. This is especially true in the cornu ammonis (CA)1 hippocampal subfield, a region that is critically involved in the pathophysiology of the illness. We thus performed a quantitative immunoblot experiment to examine PSD95 and several of its associated proteins in the CA1 region, using post mortem brain samples derived from schizophrenia subjects with age-, sex-, and post mortem interval-matched controls (n=20/group). Our results indicate a substantial reduction in PSD95 protein expression (-61.8%). Further analysis showed additional alterations to the scaffold protein Homer1 (Homer1a: +42.9%, Homer1b/c: -24.6%), with a twofold reduction in the ratio of Homer1b/c:Homer1a isoforms (P=0.011). Metabotropic glutamate receptor 1 (mGluR1) protein levels were significantly reduced (-32.7%), and Preso, a protein that supports interactions between Homer1 or PSD95 with mGluR1, was elevated (+83.3%). Significant reduction in synaptophysin (-27.8%) was also detected, which is a validated marker of synaptic density. These findings support the presence of extensive molecular abnormalities to PSD95 and several of its associated proteins in the CA1 region in schizophrenia, offering a small but significant step toward understanding how proteins in the PSD are altered in the schizophrenia brain, and their relevance to overall hippocampal and cognitive dysfunction in the illness.
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162
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Changes in synaptic plasticity and expression of glutamate receptor subunits in the CA1 and CA3 areas of the hippocampus after transient global ischemia. Neuroscience 2016; 327:64-78. [PMID: 27090818 DOI: 10.1016/j.neuroscience.2016.04.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 12/26/2022]
Abstract
Excess glutamate release from the presynaptic membrane has been thought to be the major cause of ischemic neuronal death. Although both CA1 and CA3 pyramidal neurons receive presynaptic glutamate input, transient cerebral ischemia induces CA1 neurons to die while CA3 neurons remain relatively intact. This suggests that changes in the properties of pyramidal cells may be the main cause related to ischemic neuronal death. Our previous studies have shown that the densities of dendritic spines and asymmetric synapses in the CA1 area are increased at 12h and 24h after ischemia. In the present study, we investigated changes in synaptic structures in the CA3 area and compared the expression of glutamate receptors in the CA1 and CA3 hippocampal regions of rats after ischemia. Our results demonstrated that the NR2B/NR2A ratio became larger after ischemia although the expression of both the NR2B subunit (activation of apoptotic pathway) and NR2A subunit (activation of survival pathway) decreased in the CA1 area from 6h to 48h after reperfusion. Furthermore, expression of the GluR2 subunit (calcium impermeable) of the AMPA receptor class significantly decreased while the GluR1 subunit (calcium permeable) remained unchanged at the same examined reperfusion times, which subsequently caused an increase in the GluR1/GluR2 ratio. Despite these notable differences in subunit expression, there were no obvious changes in the density of synapses or expression of NMDAR and AMPAR subunits in the CA3 area after ischemia. These results suggest that delayed CA1 neuronal death may be related to the dramatic fluctuation in the synaptic structure and relative upregulation of NR2B and GluR1 subunits induced by transient global ischemia.
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163
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Fernandes J, Soares JCK, do Amaral Baliego LGZ, Arida RM. A single bout of resistance exercise improves memory consolidation and increases the expression of synaptic proteins in the hippocampus. Hippocampus 2016; 26:1096-103. [PMID: 27008926 DOI: 10.1002/hipo.22590] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 03/09/2016] [Accepted: 03/10/2016] [Indexed: 02/06/2023]
Abstract
Over the past decade, several studies have indicated that chronic resistance exercise (i.e., strength training, weight lifting, etc.) is beneficial for brain health and cognitive function. However, little is known about the effects of a single bout of resistance exercise on brain function, particularly on memory consolidation. Therefore, the purpose of the present study is to examine the effects of a single bout of resistance exercise applied immediately after the training of fear conditioning on memory consolidation and on the expression of IGF-1 and synaptic proteins in the hippocampus. Male Wistar rats were familiarized with climbing a ladder without a load for 3 days and randomly assigned into control (CTL) and resistance exercise (RES) groups. The RES group was subjected to a single bout of resistance exercise applied immediately after fear conditioning training. Subsequently, the animals were tested for contextual (24 h) and tone (48 h) fear memory. Another group of animals were subjected to a single bout of resistance exercise and euthanized 24 h later for hippocampal analysis of IGF-1 and synaptic proteins (synapsin I, synaptophysin, and PSD-95). The exercised rats improved contextual but not tone fear memory. Hippocampal IGF-1 was not altered by resistance exercise. However, the levels of synapsin I, synaptophysin, and PSD-95 increased significantly in the RES group. The results suggested that a single bout of resistance exercise applied immediately after fear conditioning could improve contextual memory, probably through the activation of pre- and postsynaptic machinery required for memory consolidation. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Jansen Fernandes
- Department of Physiology, Universidade Federal De São Paulo (UNIFESP), São Paulo, Brazil
| | | | | | - Ricardo Mario Arida
- Department of Physiology, Universidade Federal De São Paulo (UNIFESP), São Paulo, Brazil
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164
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Posttranslational Modifications Regulate the Postsynaptic Localization of PSD-95. Mol Neurobiol 2016; 54:1759-1776. [PMID: 26884267 DOI: 10.1007/s12035-016-9745-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/22/2016] [Indexed: 01/08/2023]
Abstract
The postsynaptic density (PSD) consists of a lattice-like array of interacting proteins that organizes and stabilizes synaptic receptors, ion channels, structural proteins, and signaling molecules required for normal synaptic transmission and synaptic function. The scaffolding and hub protein postsynaptic density protein-95 (PSD-95) is a major element of central chemical synapses and interacts with glutamate receptors, cell adhesion molecules, and cytoskeletal elements. In fact, PSD-95 can regulate basal synaptic stability as well as the activity-dependent structural plasticity of the PSD and, therefore, of the excitatory chemical synapse. Several studies have shown that PSD-95 is highly enriched at excitatory synapses and have identified multiple protein structural domains and protein-protein interactions that mediate PSD-95 function and trafficking to the postsynaptic region. PSD-95 is also a target of several signaling pathways that induce posttranslational modifications, including palmitoylation, phosphorylation, ubiquitination, nitrosylation, and neddylation; these modifications determine the synaptic stability and function of PSD-95 and thus regulate the fates of individual dendritic spines in the nervous system. In the present work, we review the posttranslational modifications that regulate the synaptic localization of PSD-95 and describe their functional consequences. We also explore the signaling pathways that induce such changes.
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165
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Abstract
Precise regulation of protein assembly at specialized membrane domains is essential for diverse cellular functions including synaptic transmission. However, it is incompletely understood how protein clustering at the plasma membrane is initiated, maintained and controlled. Protein palmitoylation, a common post-translational modification, regulates protein targeting to the plasma membrane. Such modified proteins are enriched in these specialized membrane domains. In this review, we focus on palmitoylation of PSD-95, which is a major postsynaptic scaffolding protein and makes discrete postsynaptic nanodomains in a palmitoylation-dependent manner and discuss a determinant role of local palmitoylation cycles in creating highly localized hotspots at the membrane where specific proteins concentrate to organize functional domains.
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166
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Wee KSL, Tan FCK, Cheong YP, Khanna S, Low CM. Ontogenic Profile and Synaptic Distribution of GluN3 Proteins in the Rat Brain and Hippocampal Neurons. Neurochem Res 2015; 41:290-7. [DOI: 10.1007/s11064-015-1794-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 11/27/2015] [Accepted: 11/28/2015] [Indexed: 12/01/2022]
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167
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PSD-95 family MAGUKs are essential for anchoring AMPA and NMDA receptor complexes at the postsynaptic density. Proc Natl Acad Sci U S A 2015; 112:E6983-92. [PMID: 26604311 DOI: 10.1073/pnas.1517045112] [Citation(s) in RCA: 195] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The postsynaptic density (PSD)-95 family of membrane-associated guanylate kinases (MAGUKs) are major scaffolding proteins at the PSD in glutamatergic excitatory synapses, where they maintain and modulate synaptic strength. How MAGUKs underlie synaptic strength at the molecular level is still not well understood. Here, we explore the structural and functional roles of MAGUKs at hippocampal excitatory synapses by simultaneous knocking down PSD-95, PSD-93, and synapse-associated protein (SAP)102 and combining electrophysiology and transmission electron microscopic (TEM) tomography imaging to analyze the resulting changes. Acute MAGUK knockdown greatly reduces synaptic transmission mediated by α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptors (AMPARs) and N-methyl-d-aspartate receptors (NMDARs). This knockdown leads to a significant rise in the number of silent synapses, diminishes the size of PSDs without changes in pre- or postsynaptic membrane, and depletes the number of membrane-associated PSD-95-like vertical filaments and transmembrane structures, identified as AMPARs and NMDARs by EM tomography. The differential distribution of these receptor-like structures and dependence of their abundance on PSD size matches that of AMPARs and NMDARs in the hippocampal synapses. The loss of these structures following MAGUK knockdown tracks the reduction in postsynaptic AMPAR and NMDAR transmission, confirming the structural identities of these two types of receptors. These results demonstrate that MAGUKs are required for anchoring both types of glutamate receptors at the PSD and are consistent with a structural model where MAGUKs, corresponding to membrane-associated vertical filaments, are the essential structural proteins that anchor and organize both types of glutamate receptors and govern the overall molecular organization of the PSD.
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Levy JM, Chen X, Reese TS, Nicoll RA. Synaptic Consolidation Normalizes AMPAR Quantal Size following MAGUK Loss. Neuron 2015; 87:534-48. [PMID: 26247861 DOI: 10.1016/j.neuron.2015.07.015] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 06/09/2015] [Accepted: 07/20/2015] [Indexed: 11/15/2022]
Abstract
The mechanisms controlling synapse growth and maintenance are of critical importance for learning and memory. The MAGUK family of synaptic scaffolding proteins is abundantly expressed at glutamatergic central synapses, but their importance in controlling the synaptic content of glutamate receptors is poorly understood. Here, we use a chained RNAi-mediated knockdown approach to simultaneously remove PSD-93, PSD-95, and SAP102, the MAGUKs previously shown to be responsible for synaptic localization of glutamate receptors. We find that MAGUKs are specifically responsible for creating functional synapses after initial spine formation by filling functionally silent spines with glutamate receptors. Removal of the MAGUKs causes a transient reduction in AMPA receptor quantal size followed by synaptic consolidation resulting in a normalization of quantal size at the few remaining functional synapses. Consolidation requires signaling through L-type calcium channels, CaM kinase kinase, and the GluA2 AMPA receptor subunit, akin to a homeostatic process.
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Affiliation(s)
- Jonathan M Levy
- Neuroscience Graduate Program, University of California San Francisco, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Xiaobing Chen
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thomas S Reese
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Roger A Nicoll
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94158, USA.
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170
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Hruska M, Henderson NT, Xia NL, Le Marchand SJ, Dalva MB. Anchoring and synaptic stability of PSD-95 is driven by ephrin-B3. Nat Neurosci 2015; 18:1594-605. [PMID: 26479588 PMCID: PMC5396457 DOI: 10.1038/nn.4140] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 09/17/2015] [Indexed: 02/07/2023]
Abstract
Organization of signaling complexes at excitatory synapses by Membrane Associated Guanylate Kinase (MAGUK) proteins regulates synapse development, plasticity, senescence, and disease. Post-translational modification of MAGUK family proteins can drive their membrane localization, yet it is unclear how these intracellular proteins are targeted to sites of synaptic contact. Here we show using super-resolution imaging, biochemical approaches, and in vivo models that the trans-synaptic organizing protein, ephrin-B3, controls the synaptic localization and stability of PSD-95 and links these events to changes in neuronal activity via negative regulation of a novel MAPK-dependent phosphorylation site on ephrin-B3 (S332). Unphosphorylated ephrin-B3 is enriched at synapses, interacts directly with and stabilizes PSD-95 at synapses. Activity induced phosphorylation of S332 disperses ephrin-B3 from synapses, prevents the interaction with, and enhances the turnover of PSD-95. Thus, ephrin-B3 specifies the synaptic localization of PSD-95 and likely links the synaptic stability of PSD-95 to changes in neuronal activity.
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Affiliation(s)
- Martin Hruska
- Department of Neuroscience and the Farber Institute for Neuroscience, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, Pennsylvania, USA
| | - Nathan T Henderson
- Department of Neuroscience and the Farber Institute for Neuroscience, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, Pennsylvania, USA
| | - Nan L Xia
- Department of Neuroscience and the Farber Institute for Neuroscience, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, Pennsylvania, USA
| | - Sylvain J Le Marchand
- Department of Neuroscience and the Farber Institute for Neuroscience, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, Pennsylvania, USA
| | - Matthew B Dalva
- Department of Neuroscience and the Farber Institute for Neuroscience, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, Pennsylvania, USA
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171
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Neonatal vaccination with bacillus Calmette-Guérin and hepatitis B vaccines modulates hippocampal synaptic plasticity in rats. J Neuroimmunol 2015; 288:1-12. [PMID: 26531688 DOI: 10.1016/j.jneuroim.2015.08.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 08/08/2015] [Accepted: 08/19/2015] [Indexed: 11/21/2022]
Abstract
Immune activation can exert multiple effects on synaptic transmission. Our study demonstrates the influence of neonatal vaccination on hippocampal synaptic plasticity in rats under normal physiological conditions. The results revealed that neonatal BCG vaccination enhanced synaptic plasticity. In contrast, HBV hampered it. Furthermore, we found that the cytokine balance shifted in favour of the T helper type 1/T helper type 2 immune response in BCG/HBV-vaccinated rats in the periphery. The peripheral IFN-γ:IL-4 ratio was positively correlated with BDNF and IGF-1 in the hippocampus. BCG raised IFN-γ, IL-4, BDNF and IGF-1 and reduced IL-1β, IL-6, and TNF-α in the hippocampus, whereas, HBV triggered the opposite effects.
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172
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Wang LF, Wei L, Qiao SM, Gao XN, Gao YB, Wang SM, Zhao L, Dong J, Xu XP, Zhou HM, Hu XJ, Peng RY. Microwave-Induced Structural and Functional Injury of Hippocampal and PC12 Cells Is Accompanied by Abnormal Changes in the NMDAR-PSD95-CaMKII Pathway. Pathobiology 2015; 82:181-94. [PMID: 26337368 DOI: 10.1159/000398803] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 04/09/2015] [Indexed: 11/19/2022] Open
Abstract
Recent studies have highlighted the important role of the postsynaptic NMDAR-PSD95-CaMKII pathway for synaptic transmission and related neuronal injury. Here, we tested changes in the components of this pathway upon microwave-induced neuronal structure and function impairments. Ultrastructural and functional changes were induced in hippocampal neurons of rats and in PC12 cells exposed to microwave radiation. We detected abnormal protein and mRNA expression, as well as posttranslational modifications in the NMDAR-PSD95-CaMKII pathway and its associated components, such as synapsin I, following microwave radiation exposure of rats and PC12 cells. Thus, microwave radiation may induce neuronal injury via changes in the molecular organization of postsynaptic density and modulation of the biochemical cascade that potentiates synaptic transmission.
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Affiliation(s)
- Li-Feng Wang
- Laboratory of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, China
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Rat Nasal Respiratory Mucosa-Derived Ectomesenchymal Stem Cells Differentiate into Schwann-Like Cells Promoting the Differentiation of PC12 Cells and Forming Myelin In Vitro. Stem Cells Int 2015; 2015:328957. [PMID: 26339250 PMCID: PMC4539076 DOI: 10.1155/2015/328957] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 01/03/2015] [Accepted: 01/04/2015] [Indexed: 01/23/2023] Open
Abstract
Schwann cell (SC) transplantation as a cell-based therapy can enhance peripheral and central nerve repair experimentally, but it is limited by the donor site morbidity for clinical application. We investigated weather respiratory mucosa stem cells (REMSCs), a kind of ectomesenchymal stem cells (EMSCs), isolated from rat nasal septum can differentiate into functional Schwann-like cells (SC-like cells). REMSCs proliferated quickly in vitro and expressed the neural crest markers (nestin, vimentin, SOX10, and CD44). Treated with a mixture of glial growth factors for 7 days, REMSCs differentiated into SC-like cells. The differentiated REMSCs (dREMSCs) exhibited a spindle-like morphology similar to SC cells. Immunocytochemical staining and Western blotting indicated that SC-like cells expressed the glial markers (GFAP, S100β, Galc, and P75) and CNPase. When cocultured with dREMSCs for 5 days, PC12 cells differentiated into mature neuron-like cells with long neurites. More importantly, dREMSCs could form myelin structures with the neurites of PC12 cells at 21 days in vitro. Our data indicated that REMSCs, a kind of EMSCs, could differentiate into SC-like cells and have the ability to promote the differentiation of PC12 cells and form myelin in vitro.
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174
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The LGI1-ADAM22 protein complex directs synapse maturation through regulation of PSD-95 function. Proc Natl Acad Sci U S A 2015; 112:E4129-37. [PMID: 26178195 DOI: 10.1073/pnas.1511910112] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Synapse development is coordinated by a number of transmembrane and secreted proteins that come together to form synaptic organizing complexes. Whereas a variety of synaptogenic proteins have been characterized, much less is understood about the molecular networks that support the maintenance and functional maturation of nascent synapses. Here, we demonstrate that leucine-rich, glioma-inactivated protein 1 (LGI1), a secreted protein previously shown to modulate synaptic AMPA receptors, is a paracrine signal released from pre- and postsynaptic neurons that acts specifically through a disintegrin and metalloproteinase protein 22 (ADAM22) to set postsynaptic strength. We go on to describe a novel role for ADAM22 in maintaining excitatory synapses through PSD-95/Dlg1/zo-1 (PDZ) domain interactions. Finally, we show that in the absence of LGI1, the mature synapse scaffolding protein PSD-95, but not the immature synapse scaffolding protein SAP102, is unable to modulate synaptic transmission. These results indicate that LGI1 and ADAM22 form an essential synaptic organizing complex that coordinates the maturation of excitatory synapses by regulating the functional incorporation of PSD-95.
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175
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Fitzgerald PJ, Pinard CR, Camp MC, Feyder M, Sah A, Bergstrom H, Graybeal C, Liu Y, Schlüter O, Grant SG, Singewald N, Xu W, Holmes A. Durable fear memories require PSD-95. Mol Psychiatry 2015; 20:901-12. [PMID: 25510511 PMCID: PMC4469631 DOI: 10.1038/mp.2014.161] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 07/28/2014] [Accepted: 10/15/2014] [Indexed: 12/13/2022]
Abstract
Traumatic fear memories are highly durable but also dynamic, undergoing repeated reactivation and rehearsal over time. Although overly persistent fear memories underlie anxiety disorders, such as posttraumatic stress disorder, the key neural and molecular mechanisms underlying fear memory durability remain unclear. Postsynaptic density 95 (PSD-95) is a synaptic protein regulating glutamate receptor anchoring, synaptic stability and certain types of memory. Using a loss-of-function mutant mouse lacking the guanylate kinase domain of PSD-95 (PSD-95(GK)), we analyzed the contribution of PSD-95 to fear memory formation and retrieval, and sought to identify the neural basis of PSD-95-mediated memory maintenance using ex vivo immediate-early gene mapping, in vivo neuronal recordings and viral-mediated knockdown (KD) approaches. We show that PSD-95 is dispensable for the formation and expression of recent fear memories, but essential for the formation of precise and flexible fear memories and for the maintenance of memories at remote time points. The failure of PSD-95(GK) mice to retrieve remote cued fear memory was associated with hypoactivation of the infralimbic (IL) cortex (but not the anterior cingulate cortex (ACC) or prelimbic cortex), reduced IL single-unit firing and bursting, and attenuated IL gamma and theta oscillations. Adeno-associated virus-mediated PSD-95 KD in the IL, but not the ACC, was sufficient to impair recent fear extinction and remote fear memory, and remodel IL dendritic spines. Collectively, these data identify PSD-95 in the IL as a critical mechanism supporting the durability of fear memories over time. These preclinical findings have implications for developing novel approaches to treating trauma-based anxiety disorders that target the weakening of overly persistent fear memories.
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Affiliation(s)
- Paul J. Fitzgerald
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, NIH
| | - Courtney R. Pinard
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, NIH
| | - Marguerite C. Camp
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, NIH
| | - Michael Feyder
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, NIH
| | - Anupam Sah
- Department of Pharmacology & Toxicology, University of Innsbruck, Innsbruck, Austria
| | - Hadley Bergstrom
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, NIH
| | - Carolyn Graybeal
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, NIH
| | - Yan Liu
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | - Seth G.N. Grant
- Centre for Clinical Brain Sciences and Centre for Neuroregeneration, The University of Edinburgh, Edinburgh, UK
| | - Nicolas Singewald
- Department of Pharmacology & Toxicology, University of Innsbruck, Innsbruck, Austria
| | - Weifeng Xu
- Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, NIH
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High B, Cole AA, Chen X, Reese TS. Electron microscopic tomography reveals discrete transcleft elements at excitatory and inhibitory synapses. Front Synaptic Neurosci 2015; 7:9. [PMID: 26113817 PMCID: PMC4461817 DOI: 10.3389/fnsyn.2015.00009] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 05/28/2015] [Indexed: 12/24/2022] Open
Abstract
Electron microscopy has revealed an abundance of material in the clefts of synapses in the mammalian brain, and the biochemical and functional characteristics of proteins occupying synaptic clefts are well documented. However, the detailed spatial organization of the proteins in the synaptic clefts remains unclear. Electron microscope tomography provides a way to delineate and map the proteins spanning the synaptic cleft because freeze substitution preserves molecular details with sufficient contrast to visualize individual cleft proteins. Segmentation and rendering of electron dense material connected across the cleft reveals discrete structural elements that are readily classified into five types at excitatory synapses and four types at inhibitory synapses. Some transcleft elements resemble shapes and sizes of known proteins and could represent single dimers traversing the cleft. Some of the types of cleft elements at inhibitory synapses roughly matched the structure and proportional frequency of cleft elements at excitatory synapses, but the patterns of deployments in the cleft are quite different. Transcleft elements at excitatory synapses were often evenly dispersed in clefts of uniform (18 nm) width but some types show preference for the center or edges of the cleft. Transcleft elements at inhibitory synapses typically were confined to a peripheral region of the cleft where it narrowed to only 6 nm wide. Transcleft elements in both excitatory and inhibitory synapses typically avoid places where synaptic vesicles attach to the presynaptic membrane. These results illustrate that elements spanning synaptic clefts at excitatory and inhibitory synapses consist of distinct structures arranged by type in a specific but different manner at excitatory and inhibitory synapses.
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Affiliation(s)
- Brigit High
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Strokes, National Institutes of Health Bethesda, MD, USA
| | - Andy A Cole
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Strokes, National Institutes of Health Bethesda, MD, USA ; Department of Cell and Molecular Biology, Northwestern University Chicago, IL, USA
| | - Xiaobing Chen
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Strokes, National Institutes of Health Bethesda, MD, USA
| | - Thomas S Reese
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Strokes, National Institutes of Health Bethesda, MD, USA
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Patel S, Roncaglia P, Lovering RC. Using Gene Ontology to describe the role of the neurexin-neuroligin-SHANK complex in human, mouse and rat and its relevance to autism. BMC Bioinformatics 2015; 16:186. [PMID: 26047810 PMCID: PMC4458007 DOI: 10.1186/s12859-015-0622-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 05/20/2015] [Indexed: 12/24/2022] Open
Abstract
Background People with an autistic spectrum disorder (ASD) display a variety of characteristic behavioral traits, including impaired social interaction, communication difficulties and repetitive behavior. This complex neurodevelopment disorder is known to be associated with a combination of genetic and environmental factors. Neurexins and neuroligins play a key role in synaptogenesis and neurexin-neuroligin adhesion is one of several processes that have been implicated in autism spectrum disorders. Results In this report we describe the manual annotation of a selection of gene products known to be associated with autism and/or the neurexin-neuroligin-SHANK complex and demonstrate how a focused annotation approach leads to the creation of more descriptive Gene Ontology (GO) terms, as well as an increase in both the number of gene product annotations and their granularity, thus improving the data available in the GO database. Conclusions The manual annotations we describe will impact on the functional analysis of a variety of future autism-relevant datasets. Comprehensive gene annotation is an essential aspect of genomic and proteomic studies, as the quality of gene annotations incorporated into statistical analysis tools affects the effective interpretation of data obtained through genome wide association studies, next generation sequencing, proteomic and transcriptomic datasets. Electronic supplementary material The online version of this article (doi:10.1186/s12859-015-0622-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sejal Patel
- Institute of Medical Science, University of Toronto, Medical Sciences Building, 1 King's College Circle, Toronto, M5S 1A8, Canada. .,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, 250 College Street, Toronto, M5T 1R8, Canada. .,Centre for Cardiovascular Genetics, Institute of Cardiovascular Science, University College London, Rayne Building, 5 University Street, London, WC1E 6JF, UK.
| | - Paola Roncaglia
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK. .,The Gene Ontology Consortium, .
| | - Ruth C Lovering
- Centre for Cardiovascular Genetics, Institute of Cardiovascular Science, University College London, Rayne Building, 5 University Street, London, WC1E 6JF, UK.
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Goyer D, Fensky L, Hilverling AM, Kurth S, Kuenzel T. Expression of the postsynaptic scaffold PSD-95 and development of synaptic physiology during giant terminal formation in the auditory brainstem of the chicken. Eur J Neurosci 2015; 41:1416-29. [PMID: 25903469 DOI: 10.1111/ejn.12902] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/19/2015] [Indexed: 11/29/2022]
Abstract
In the avian nucleus magnocellularis (NM) endbulb of Held giant synapses develop from temporary bouton terminals. The molecular regulation of this process is not well understood. Furthermore, it is unknown how the postsynaptic specialization of the endbulb synapses develops. We therefore analysed expression of the postsynaptic scaffold protein PSD-95 during the transition from bouton-to-endbulb synapses. PSD-95 has been implicated in the regulation of the strength of glutamatergic synapses and could accordingly be of functional relevance for giant synapse formation. PSD-95 protein was expressed at synaptic sites in embryonic chicken auditory brainstem and upregulated between embryonic days (E)12 and E16. We applied immunofluorescence staining and confocal microscopy to quantify pre-and postsynaptic protein signals during bouton-to-endbulb transition. Giant terminal formation progressed along the tonotopic axis in NM, but was absent in low-frequency NM. We found a tonotopic gradient of postsynaptic PSD-95 signals in NM. Furthermore, PSD-95 immunosignals showed the greatest increase between E12 and E15, temporally preceding the bouton-to-endbulb transition. We then applied whole-cell electrophysiology to measure synaptic currents elicited by synaptic terminals during bouton-to-endbulb transition. With progressing endbulb formation postsynaptic currents rose more rapidly and synapses were less susceptible to short-term depression, but currents were not different in amplitude or decay-time constant. We conclude that development of presynaptic specializations follows postsynaptic development and speculate that the early PSD-95 increase could play a functional role in endbulb formation.
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Affiliation(s)
- David Goyer
- Department of Zoology/Animal Physiology, Institute for Biology II, RWTH Aachen University, Worringer Weg 3, D-52074, Aachen, Germany
| | - Luisa Fensky
- Department of Zoology/Animal Physiology, Institute for Biology II, RWTH Aachen University, Worringer Weg 3, D-52074, Aachen, Germany
| | - Anna Maria Hilverling
- Department of Zoology/Animal Physiology, Institute for Biology II, RWTH Aachen University, Worringer Weg 3, D-52074, Aachen, Germany
| | - Stefanie Kurth
- Department of Zoology/Animal Physiology, Institute for Biology II, RWTH Aachen University, Worringer Weg 3, D-52074, Aachen, Germany
| | - Thomas Kuenzel
- Department of Zoology/Animal Physiology, Institute for Biology II, RWTH Aachen University, Worringer Weg 3, D-52074, Aachen, Germany
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Hafner AS, Penn AC, Grillo-Bosch D, Retailleau N, Poujol C, Philippat A, Coussen F, Sainlos M, Opazo P, Choquet D. Lengthening of the Stargazin Cytoplasmic Tail Increases Synaptic Transmission by Promoting Interaction to Deeper Domains of PSD-95. Neuron 2015; 86:475-89. [PMID: 25843401 DOI: 10.1016/j.neuron.2015.03.013] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 11/17/2014] [Accepted: 02/23/2015] [Indexed: 11/28/2022]
Abstract
PSD-95 is a prominent organizer of the postsynaptic density (PSD) that can present a filamentous orientation perpendicular to the plasma membrane. Interactions between PSD-95 and transmembrane proteins might be particularly sensitive to this orientation, as "long" cytoplasmic tails might be required to reach deeper PSD-95 domains. Extension/retraction of transmembrane protein C-tails offer a new way of regulating binding to PSD-95. Using stargazin as a model, we found that enhancing the apparent length of stargazin C-tail through phosphorylation or by an artificial linker was sufficient to potentiate binding to PSD-95, AMPAR anchoring, and synaptic transmission. A linear extension of stargazin C-tail facilitates binding to PSD-95 by preferentially engaging interaction with the farthest located PDZ domains regarding to the plasma membrane, which present a greater affinity for the stargazin PDZ-domain-binding motif. Our study reveals that the concerted orientation of the stargazin C-tail and PSD-95 is a major determinant of synaptic strength.
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Affiliation(s)
- Anne-Sophie Hafner
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Andrew C Penn
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Dolors Grillo-Bosch
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Natacha Retailleau
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Christel Poujol
- Bordeaux Imaging Center, UMS 3420 CNRS, US4 INSERM, University of Bordeaux, 33000 Bordeaux, France
| | - Amandine Philippat
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Françoise Coussen
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Matthieu Sainlos
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France
| | - Patricio Opazo
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France.
| | - Daniel Choquet
- University of Bordeaux, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; CNRS, Interdisciplinary Institute for Neuroscience, UMR 5297, 33000 Bordeaux, France; Bordeaux Imaging Center, UMS 3420 CNRS, US4 INSERM, University of Bordeaux, 33000 Bordeaux, France.
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180
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Zhu D, Li C, Swanson AM, Villalba RM, Guo J, Zhang Z, Matheny S, Murakami T, Stephenson JR, Daniel S, Fukata M, Hall RA, Olson JJ, Neigh GN, Smith Y, Rainnie DG, Van Meir EG. BAI1 regulates spatial learning and synaptic plasticity in the hippocampus. J Clin Invest 2015; 125:1497-508. [PMID: 25751059 DOI: 10.1172/jci74603] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 01/15/2015] [Indexed: 12/16/2022] Open
Abstract
Synaptic plasticity is the ability of synapses to modulate the strength of neuronal connections; however, the molecular factors that regulate this feature are incompletely understood. Here, we demonstrated that mice lacking brain-specific angiogenesis inhibitor 1 (BAI1) have severe deficits in hippocampus-dependent spatial learning and memory that are accompanied by enhanced long-term potentiation (LTP), impaired long-term depression (LTD), and a thinning of the postsynaptic density (PSD) at hippocampal synapses. We showed that compared with WT animals, mice lacking Bai1 exhibit reduced protein levels of the canonical PSD component PSD-95 in the brain, which stems from protein destabilization. We determined that BAI1 prevents PSD-95 polyubiquitination and degradation through an interaction with murine double minute 2 (MDM2), the E3 ubiquitin ligase that regulates PSD-95 stability. Restoration of PSD-95 expression in hippocampal neurons in BAI1-deficient mice by viral gene therapy was sufficient to compensate for Bai1 loss and rescued deficits in synaptic plasticity. Together, our results reveal that interaction of BAI1 with MDM2 in the brain modulates PSD-95 levels and thereby regulates synaptic plasticity. Moreover, these results suggest that targeting this pathway has therapeutic potential for a variety of neurological disorders.
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181
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Wang H. Fragile X mental retardation protein: from autism to neurodegenerative disease. Front Cell Neurosci 2015; 9:43. [PMID: 25729352 PMCID: PMC4325920 DOI: 10.3389/fncel.2015.00043] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 01/28/2015] [Indexed: 11/13/2022] Open
Affiliation(s)
- Hansen Wang
- Faculty of Medicine, University of Toronto Toronto, ON, Canada
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182
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183
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Yang Y, Li G, Zhao D, Yu H, Zheng X, Peng X, Zhang X, Fu T, Hu X, Niu M, Ji X, Zou L, Wang J. Computational discovery and experimental verification of tyrosine kinase inhibitor pazopanib for the reversal of memory and cognitive deficits in rat model neurodegeneration. Chem Sci 2015; 6:2812-2821. [PMID: 28706670 PMCID: PMC5489033 DOI: 10.1039/c4sc03416c] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/12/2015] [Indexed: 01/10/2023] Open
Abstract
Pazopanib, a tyrosine kinase inhibitor marketed for cancer treatment, abrogates the course of neurodegeneration.
Cognition and memory impairment are hallmarks of the pathological cascade of various neurodegenerative disorders. Herein, we developed a novel computational strategy with two-dimensional virtual screening for not only affinity but also specificity. We integrated the two-dimensional virtual screening with ligand screening for 3D shape, electrostatic similarity and local binding site similarity to find existing drugs that may reduce the signs of cognitive deficits. For the first time, we found that pazopanib, a tyrosine kinase inhibitor marketed for cancer treatment, inhibits acetylcholinesterase (AchE) activities at sub-micromolar concentration. We evaluated and compared the effects of intragastrically-administered pazopanib with donepezil, a marketed AchE inhibitor, in cognitive and behavioral assays including the novel object recognition test, Y maze and Morris water maze test. Surprisingly, we found that pazopanib can restore memory loss and cognitive dysfunction to a similar extent as donepezil in a dosage of 15 mg kg–1, only one fifth of the equivalent clinical dosage for cancer treatment. Furthermore, we demonstrated that pazopanib dramatically enhances the hippocampal Ach levels and increases the expression of the synaptic marker SYP. These findings suggest that pazopanib may become a viable treatment option for memory and cognitive deficits with a good safety profile in humans.
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Affiliation(s)
- Yongliang Yang
- Center for Molecular Medicine , School of Life Science and Biotechnology , Dalian University of Technology , Dalian , 116023 , P. R. China .
| | - Guohui Li
- Laboratory of Molecular Modeling and Design , State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , 457 Zhongshan Rd. , Dalian 116023 , P. R. China .
| | - Dongyu Zhao
- Center for Molecular Medicine , School of Life Science and Biotechnology , Dalian University of Technology , Dalian , 116023 , P. R. China .
| | - Haoyang Yu
- Department of Life Science and Biopharmaceutics , Shenyang Pharmaceutical University , Shenyang 110016 , P. R. China .
| | - Xiliang Zheng
- State Key Laboratory of Electroanalytical Chemistry , Changchun Institute of Applied Chemistry , Chinese Academy of Sciences , Changchun , Jilin , P. R. China
| | - Xiangda Peng
- Laboratory of Molecular Modeling and Design , State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , 457 Zhongshan Rd. , Dalian 116023 , P. R. China .
| | - Xiaoe Zhang
- Center for Molecular Medicine , School of Life Science and Biotechnology , Dalian University of Technology , Dalian , 116023 , P. R. China .
| | - Ting Fu
- Laboratory of Molecular Modeling and Design , State Key Laboratory of Molecular Reaction Dynamics , Dalian Institute of Chemical Physics , Chinese Academy of Sciences , 457 Zhongshan Rd. , Dalian 116023 , P. R. China .
| | - Xiaoqing Hu
- Center for Molecular Medicine , School of Life Science and Biotechnology , Dalian University of Technology , Dalian , 116023 , P. R. China .
| | - Mingshan Niu
- Center for Molecular Medicine , School of Life Science and Biotechnology , Dalian University of Technology , Dalian , 116023 , P. R. China .
| | - Xuefei Ji
- Department of Life Science and Biopharmaceutics , Shenyang Pharmaceutical University , Shenyang 110016 , P. R. China .
| | - Libo Zou
- Department of Life Science and Biopharmaceutics , Shenyang Pharmaceutical University , Shenyang 110016 , P. R. China .
| | - Jin Wang
- State Key Laboratory of Electroanalytical Chemistry , Changchun Institute of Applied Chemistry , Chinese Academy of Sciences , Changchun , Jilin , P. R. China.,Department of Chemistry and Physics , State University of New York , Stony Brook , New York , USA .
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184
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Zinc deficiency in rats is associated with up-regulation of hippocampal NMDA receptor. Prog Neuropsychopharmacol Biol Psychiatry 2015; 56:254-63. [PMID: 25290638 DOI: 10.1016/j.pnpbp.2014.09.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 08/31/2014] [Accepted: 09/19/2014] [Indexed: 12/12/2022]
Abstract
RATIONALE Data indicated that zinc deficiency may contribute to the development of depression; however changes induced by zinc deficiency are not fully described. OBJECTIVES In the present paper we tested whether the dietary zinc restriction in rats causes alterations in N-methyl-D-aspartate receptor (NMDAR) subunits in brain regions that are relevant to depression. METHODS Male Sprague Dawley rats were fed a zinc adequate diet (ZnA, 50 mg Zn/kg) or a zinc deficient diet (ZnD, 3 mg Zn/kg) for 4 or 6weeks. Then, the behavior of the rats was examined in the forced swim test, sucrose intake test and social interaction test. Western blot assays were used to study the alterations in NMDAR subunits GluN2A and GluN2B and proteins associated with NMDAR signaling in the hippocampus (Hp) and prefrontal cortex (PFC). RESULTS Following 4 or 6 weeks of zinc restriction, behavioral despair, anhedonia and a reduction of social behavior occurred in rats with concomitant increased expression of GluN2A and GluN2B and decreased expression of the PSD-95, p-CREB and BDNF protein levels in the Hp. The up-regulation of GluN2A protein was also found in the PFC, but only after prolonged (6 weeks) zinc deprivation. CONCLUSIONS The procedure of zinc restriction in rats causes behavioral changes that share some similarities to the pathophysiology of depression. Obtained data indicated that depressive-like behavior induced by zinc deficiency is associated with the changes in NMDAR signaling pathway.
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185
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Weiler NC, Collman F, Vogelstein JT, Burns R, Smith SJ. Synaptic molecular imaging in spared and deprived columns of mouse barrel cortex with array tomography. Sci Data 2014; 1:140046. [PMID: 25977797 PMCID: PMC4411012 DOI: 10.1038/sdata.2014.46] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 10/21/2014] [Indexed: 01/26/2023] Open
Abstract
A major question in neuroscience is how diverse subsets of synaptic connections in neural circuits are affected by experience dependent plasticity to form the basis for behavioral learning and memory. Differences in protein expression patterns at individual synapses could constitute a key to understanding both synaptic diversity and the effects of plasticity at different synapse populations. Our approach to this question leverages the immunohistochemical multiplexing capability of array tomography (ATomo) and the columnar organization of mouse barrel cortex to create a dataset comprising high resolution volumetric images of spared and deprived cortical whisker barrels stained for over a dozen synaptic molecules each. These dataset has been made available through the Open Connectome Project for interactive online viewing, and may also be downloaded for offline analysis using web, Matlab, and other interfaces.
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Affiliation(s)
- Nicholas C Weiler
- Graduate Program in Neurosciences, Stanford University School of Medicine, Stanford, California 94305, USA
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Forrest Collman
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305, USA
- Allen Institute for Brain Science, Seattle, Washington 98103, USA
| | - Joshua T Vogelstein
- Department of Statistical Science, Duke University, Durham, North Carolina 27708, USA
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Randal Burns
- Department of Computer Science, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Stephen J Smith
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305, USA
- Allen Institute for Brain Science, Seattle, Washington 98103, USA
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186
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Lisman J, Raghavachari S. Biochemical principles underlying the stable maintenance of LTP by the CaMKII/NMDAR complex. Brain Res 2014; 1621:51-61. [PMID: 25511992 DOI: 10.1016/j.brainres.2014.12.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 12/01/2014] [Accepted: 12/03/2014] [Indexed: 11/17/2022]
Abstract
Memory involves the storage of information at synapses by an LTP-like process. This information storage is synapse specific and can endure for years despite the turnover of all synaptic proteins. There must, therefore, be special principles that underlie the stability of LTP. Recent experimental results suggest that LTP is maintained by the complex of CaMKII with the NMDAR. Here we consider the specifics of the CaMKII/NMDAR molecular switch, with the goal of understanding the biochemical principles that underlie stable information storage by synapses. Consideration of a variety of experimental results suggests that multiple principles are involved. One switch requirement is to prevent spontaneous transitions from the off to the on state. The highly cooperative nature of CaMKII autophosphorylation by Ca(2+) (Hill coefficient of 8) and the fact that formation of the CaMKII/NMDAR complex requires release of CaMKII from actin are mechanisms that stabilize the off state. The stability of the on state depends critically on intersubunit autophosphorylation, a process that restores any loss of pT286 due to phosphatase activity. Intersubunit autophosphorylation is also important in explaining why on state stability is not compromised by protein turnover. Recent evidence suggests that turnover occurs by subunit exchange. Thus, stability could be achieved if a newly inserted unphosphorylated subunit was autophosphorylated by a neighboring subunit. Based on other recent work, we posit a novel mechanism that enhances the stability of the on state by protection of pT286 from phosphatases. We posit that the binding of the NMNDAR to CaMKII forces pT286 into the catalytic site of a neighboring subunit, thereby protecting pT286 from phosphatases. A final principle concerns the role of structural changes. The binding of CaMKII to the NMDAR may act as a tag to organize the binding of further proteins that produce the synapse enlargement that underlies late LTP. We argue that these structural changes not only enhance transmission, but also enhance the stability of the CaMKII/NMDAR complex. Together, these principles provide a mechanistic framework for understanding how individual synapses produce stable information storage. This article is part of a Special Issue entitled SI: Brain and Memory.
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Affiliation(s)
- John Lisman
- Brandeis University, Department of Biology and Volen Center for Complex Systems, 415 South Street-MS008, Waltham, MA 02454, United States Minor Outlying Islands.
| | - Sridhar Raghavachari
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, United States
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187
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Petrini EM, Barberis A. Diffusion dynamics of synaptic molecules during inhibitory postsynaptic plasticity. Front Cell Neurosci 2014; 8:300. [PMID: 25294987 PMCID: PMC4171989 DOI: 10.3389/fncel.2014.00300] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 09/05/2014] [Indexed: 12/24/2022] Open
Abstract
The plasticity of inhibitory transmission is expected to play a key role in the modulation of neuronal excitability and network function. Over the last two decades, the investigation of the determinants of inhibitory synaptic plasticity has allowed distinguishing presynaptic and postsynaptic mechanisms. While there has been a remarkable progress in the characterization of presynaptically-expressed plasticity of inhibition, the postsynaptic mechanisms of inhibitory long-term synaptic plasticity only begin to be unraveled. At postsynaptic level, the expression of inhibitory synaptic plasticity involves the rearrangement of the postsynaptic molecular components of the GABAergic synapse, including GABAA receptors, scaffold proteins and structural molecules. This implies a dynamic modulation of receptor intracellular trafficking and receptor surface lateral diffusion, along with regulation of the availability and distribution of scaffold proteins. This Review will focus on the mechanisms of the multifaceted molecular reorganization of the inhibitory synapse during postsynaptic plasticity, with special emphasis on the key role of protein dynamics to ensure prompt and reliable activity-dependent adjustments of synaptic strength.
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Affiliation(s)
- Enrica Maria Petrini
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genoa, Italy
| | - Andrea Barberis
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genoa, Italy
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188
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Linsalata AE, Chen X, Winters CA, Reese TS. Electron tomography on γ-aminobutyric acid-ergic synapses reveals a discontinuous postsynaptic network of filaments. J Comp Neurol 2014; 522:921-36. [PMID: 23982982 DOI: 10.1002/cne.23453] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 08/05/2013] [Accepted: 08/13/2013] [Indexed: 12/16/2022]
Abstract
The regulation of synaptic strength at γ-aminobutyric acid (GABA)-ergic synapses is dependent on the dynamic capture, retention, and modulation of GABA A-type receptors by cytoplasmic proteins at GABAergic postsynaptic sites. How these proteins are oriented and organized in the postsynaptic cytoplasm is not yet established. To better understand these structures and gain further insight into the mechanisms by which they regulate receptor populations at postsynaptic sites, we utilized electron tomography to examine GABAergic synapses in dissociated rat hippocampal cultures. GABAergic synapses were identified and selected for tomography by using a set of criteria derived from the structure of immunogold-labeled GABAergic synapses. Tomography revealed a complex postsynaptic network composed of filaments that extend ∼ 100 nm into the cytoplasm from the postsynaptic membrane. The distribution of these postsynaptic filaments was strikingly similar to that of the immunogold label for gephyrin. Filaments were interconnected through uniform patterns of contact, forming complexes composed of 2-12 filaments each. Complexes did not link to form an integrated, continuous scaffold, suggesting that GABAergic postsynaptic specializations are less rigidly organized than glutamatergic postsynaptic densities.
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Affiliation(s)
- Alexander E Linsalata
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, 20892
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189
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Changes in memory and synaptic plasticity induced in male rats after maternal exposure to bisphenol A. Toxicology 2014; 322:51-60. [DOI: 10.1016/j.tox.2014.05.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 04/30/2014] [Accepted: 05/01/2014] [Indexed: 11/17/2022]
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190
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Nikitczuk JS, Patil SB, Matikainen-Ankney BA, Scarpa J, Shapiro ML, Benson DL, Huntley GW. N-cadherin regulates molecular organization of excitatory and inhibitory synaptic circuits in adult hippocampus in vivo. Hippocampus 2014; 24:943-962. [PMID: 24753442 DOI: 10.1002/hipo.22282] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 04/09/2014] [Indexed: 12/31/2022]
Abstract
N-Cadherin and β-catenin form a transsynaptic adhesion complex required for spine and synapse development. In adulthood, N-cadherin mediates persistent synaptic plasticity, but whether the role of N-cadherin at mature synapses is similar to that at developing synapses is unclear. To address this, we conditionally ablated N-cadherin from excitatory forebrain synapses in mice starting in late postnatal life and examined hippocampal structure and function in adulthood. In the absence of N-cadherin, β-catenin levels were reduced, but numbers of excitatory synapses were unchanged, and there was no impact on number or shape of dendrites or spines. However, the composition of synaptic molecules was altered. Levels of GluA1 and its scaffolding protein PSD95 were diminished and the density of immunolabeled puncta was decreased, without effects on other glutamate receptors and their scaffolding proteins. Additionally, loss of N-cadherin at excitatory synapses triggered increases in the density of markers for inhibitory synapses and decreased severity of hippocampal seizures. Finally, adult mutant mice were profoundly impaired in hippocampal-dependent memory for spatial episodes. These results demonstrate a novel function for the N-cadherin/β-catenin complex in regulating ionotropic receptor composition of excitatory synapses, an appropriate balance of excitatory and inhibitory synaptic proteins and the maintenance of neural circuitry necessary to generate flexible yet persistent cognitive and synaptic function.
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Affiliation(s)
- Jessica S Nikitczuk
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - Shekhar B Patil
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - Bridget A Matikainen-Ankney
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - Joseph Scarpa
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - Matthew L Shapiro
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - Deanna L Benson
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
| | - George W Huntley
- Fishberg Department of Neuroscience, Friedman Brain Institute and The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY 10029
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191
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Bustos FJ, Varela-Nallar L, Campos M, Henriquez B, Phillips M, Opazo C, Aguayo LG, Montecino M, Constantine-Paton M, Inestrosa NC, van Zundert B. PSD95 suppresses dendritic arbor development in mature hippocampal neurons by occluding the clustering of NR2B-NMDA receptors. PLoS One 2014; 9:e94037. [PMID: 24705401 PMCID: PMC3976375 DOI: 10.1371/journal.pone.0094037] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 03/10/2014] [Indexed: 11/19/2022] Open
Abstract
Considerable evidence indicates that the NMDA receptor (NMDAR) subunits NR2A and NR2B are critical mediators of synaptic plasticity and dendritogenesis; however, how they differentially regulate these processes is unclear. Here we investigate the roles of the NR2A and NR2B subunits, and of their scaffolding proteins PSD-95 and SAP102, in remodeling the dendritic architecture of developing hippocampal neurons (2–25 DIV). Analysis of the dendritic architecture and the temporal and spatial expression patterns of the NMDARs and anchoring proteins in immature cultures revealed a strong positive correlation between synaptic expression of the NR2B subunit and dendritogenesis. With maturation, the pruning of dendritic branches was paralleled by a strong reduction in overall and synaptic expression of NR2B, and a significant elevation in synaptic expression of NR2A and PSD95. Using constructs that alter the synaptic composition, we found that either over-expression of NR2B or knock-down of PSD95 by shRNA-PSD95 augmented dendritogenesis in immature neurons. Reactivation of dendritogenesis could also be achieved in mature cultured neurons, but required both manipulations simultaneously, and was accompanied by increased dendritic clustering of NR2B. Our results indicate that the developmental increase in synaptic expression of PSD95 obstructs the synaptic clustering of NR2B-NMDARs, and thereby restricts reactivation of dendritic branching. Experiments with shRNA-PSD95 and chimeric NR2A/NR2B constructs further revealed that C-terminus of the NR2B subunit (tail) was sufficient to induce robust dendritic branching in mature hippocampal neurons, and suggest that the NR2B tail is important in recruiting calcium-dependent signaling proteins and scaffolding proteins necessary for dendritogenesis.
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Affiliation(s)
- Fernando J. Bustos
- Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile
- Faculty of Biological Science, Universidad de Concepción, Concepción, Chile
- FONDAP Center for Genome Regulation, Santiago, Chile
| | - Lorena Varela-Nallar
- Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile
- Department of Molecular and Cellular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Matias Campos
- Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile
| | - Berta Henriquez
- Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile
| | - Marnie Phillips
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Carlos Opazo
- Faculty of Biological Science, Universidad de Concepción, Concepción, Chile
| | - Luis G. Aguayo
- Faculty of Biological Science, Universidad de Concepción, Concepción, Chile
| | - Martin Montecino
- Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile
- FONDAP Center for Genome Regulation, Santiago, Chile
| | - Martha Constantine-Paton
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Nibaldo C. Inestrosa
- Department of Molecular and Cellular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Brigitte van Zundert
- Center for Biomedical Research, Faculty of Biological Sciences and Faculty of Medicine, Universidad Andres Bello, Santiago, Chile
- * E-mail:
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192
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Abstract
The appearance and disappearance of dendritic spines, accompanied by synapse formation and elimination may underlie the experience-dependent reorganization of cortical circuits. The exact temporal relationship between spine and synapse formation in vivo remains unclear, as does the extent to which synapse formation enhances the stability of newly formed spines and whether transient spines produce synapses. We used in utero electroporation of DsRedExpress- and eGFP-tagged postsynaptic density protein 95 (PSD-95) to investigate the relationship between spine and PSD stability in mouse neocortical L2/3 pyramidal cells in vivo. Similar to previous studies, spines and synapses appeared and disappeared, even in naive animals. Cytosolic spine volumes and PSD-95-eGFP levels in spines covaried over time, suggesting that the strength of many individual synapses continuously changes in the adult neocortex. The minority of newly formed spines acquired PSD-95-eGFP puncta. Spines that failed to acquire a PSD rarely survived for more than a day. Although PSD-95-eGFP accumulation was associated with increased spine lifetimes, most new spines with a PSD did not convert into persistent spines. This indicates that transient spines may serve to produce short-lived synaptic contacts. Persistent spines that were destined to disappear showed, on average, reduced PSD-95-eGFP levels well before the actual pruning event. Altogether, our data indicate that the PSD size relates to spine stability in vivo.
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193
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Hirabayashi A, Fukunaga Y, Miyazawa A. Structural analysis of the PSD-95 cluster by electron tomography and CEMOVIS: a proposal for the application of the genetically encoded metallothionein tag. Microscopy (Oxf) 2014; 63:227-34. [DOI: 10.1093/jmicro/dfu006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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194
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195
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Visualizing the Ultrastructures and Dynamics of Synapses by Single-Molecule Nanoscopy. NEUROMETHODS 2014. [DOI: 10.1007/978-1-4614-9179-8_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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196
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MacDougall MJ, Fine A. The expression of long-term potentiation: reconciling the preists and the postivists. Philos Trans R Soc Lond B Biol Sci 2013; 369:20130135. [PMID: 24298138 DOI: 10.1098/rstb.2013.0135] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Long-term potentiation (LTP) of excitatory synaptic transmission in the hippocampus has been investigated in great detail over the past 40 years. Where and how LTP is actually expressed, however, remain controversial issues. Considerable evidence has been offered to support both pre- and postsynaptic contributions to LTP expression. Though it is widely held that postsynaptic expression mechanisms are the primary contributors to LTP expression, evidence for that conclusion is amenable to alternative explanations. Here, we briefly review some key contributions to the 'locus' debate and describe data that support a dominant role for presynaptic mechanisms. Recognition of the state-dependency of expression mechanisms, and consideration of the consequences of the spatial relationship between postsynaptic glutamate receptors and presynaptic vesicular release sites, lead to a model that may reconcile views from both sides of the synapse.
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Affiliation(s)
- Matthew J MacDougall
- Department of Physiology and Biophysics, Dalhousie University Faculty of Medicine, , Halifax, Nova Scotia, Canada , B3H 4R2
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197
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Super-resolution imaging reveals that AMPA receptors inside synapses are dynamically organized in nanodomains regulated by PSD95. J Neurosci 2013; 33:13204-24. [PMID: 23926273 DOI: 10.1523/jneurosci.2381-12.2013] [Citation(s) in RCA: 424] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The spatiotemporal organization of neurotransmitter receptors in postsynaptic membranes is a fundamental determinant of synaptic transmission and information processing by the brain. Using four independent super-resolution light imaging methods and EM of genetically tagged and endogenous receptors, we show that, in rat hippocampal neurons, AMPARs are often highly concentrated inside synapses into a few clusters of ∼70 nm that contain ∼20 receptors. AMPARs are stabilized reversibly in these nanodomains and diffuse freely outside them. Nanodomains are dynamic in their shape and position within synapses and can form or disappear within minutes, although they are mostly stable for up to 1 h. AMPAR nanodomains are often, but not systematically, colocalized with clusters of the scaffold protein PSD95, which are generally of larger size than AMPAR nanoclusters. PSD95 expression level regulates AMPAR nanodomain size and compactness in parallel to miniature EPSC amplitude. Monte Carlo simulations further indicate the impact of AMPAR concentration in clusters on the efficacy of synaptic transmission. The observation that AMPARs are highly concentrated in nanodomains, instead of diffusively distributed in the PSD as generally thought, has important consequences on our understanding of excitatory neurotransmission. Furthermore, our results indicate that glutamatergic synaptic transmission is controlled by the nanometer-scale regulation of the size of these highly concentrated nanodomains.
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198
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Phosphorylation of threonine-19 of PSD-95 by GSK-3β is required for PSD-95 mobilization and long-term depression. J Neurosci 2013; 33:12122-35. [PMID: 23864697 DOI: 10.1523/jneurosci.0131-13.2013] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Activity of glycogen synthase kinase-3β (GSK-3β) is required for long-term depression (LTD) via molecular mechanisms that are incompletely understood. Here, we report that PSD-95, a major scaffold protein of the postsynaptic density (PSD) that promotes synaptic strength, is phosphorylated on threonine-19 (T19) by GSK-3β. In cultured rat hippocampal neurons, phosphorylation of T19 increases rapidly with chemical LTD and is attenuated by pharmacologic or genetic suppression of GSK-3β. In organotypic rat hippocampal slices, we find that a nonphosphorylatable PSD-95 mutant (T19A) tagged with photoactivatable green fluorescent protein (PAGFP) shows enhanced stability in dendritic spines versus wild-type PSD-95, whereas the phosphomimetic mutant (PSD-95-T19D) is more readily dispersed. Further, overexpression of PSD-95-T19A, but not WT-PSD-95, impairs AMPA receptor internalization and the induction of LTD. These data indicate that phosphorylation on T19 by GSK-3β destabilizes PSD-95 within the PSD and is a critical step for AMPA receptor mobilization and LTD.
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199
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Fukata Y, Dimitrov A, Boncompain G, Vielemeyer O, Perez F, Fukata M. Local palmitoylation cycles define activity-regulated postsynaptic subdomains. ACTA ACUST UNITED AC 2013; 202:145-61. [PMID: 23836932 PMCID: PMC3704990 DOI: 10.1083/jcb.201302071] [Citation(s) in RCA: 210] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Local palmitoylation machinery has an instructive role in creating activity-responsive PSD-95 nanodomains, which contribute to postsynaptic density (re)organization. Distinct PSD-95 clusters are primary landmarks of postsynaptic densities (PSDs), which are specialized membrane regions for synapses. However, the mechanism that defines the locations of PSD-95 clusters and whether or how they are reorganized inside individual dendritic spines remains controversial. Because palmitoylation regulates PSD-95 membrane targeting, we combined a conformation-specific recombinant antibody against palmitoylated PSD-95 with live-cell super-resolution imaging and discovered subsynaptic nanodomains composed of palmitoylated PSD-95 that serve as elementary units of the PSD. PSD-95 in nanodomains underwent continuous de/repalmitoylation cycles driven by local palmitoylating activity, ensuring the maintenance of compartmentalized PSD-95 clusters within individual spines. Plasma membrane targeting of DHHC2 palmitoyltransferase rapidly recruited PSD-95 to the plasma membrane and proved essential for postsynaptic nanodomain formation. Furthermore, changes in synaptic activity rapidly reorganized PSD-95 nano-architecture through plasma membrane–inserted DHHC2. Thus, the first genetically encoded antibody sensitive to palmitoylation reveals an instructive role of local palmitoylation machinery in creating activity-responsive PSD-95 nanodomains, contributing to the PSD (re)organization.
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Affiliation(s)
- Yuko Fukata
- Division of Membrane Physiology, Department of Cell Physiology, National Institute for Physiological Sciences, Okazaki, Aichi 444-8787, Japan
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Ke C, Li C, Huang X, Cao F, Shi D, He W, Bu H, Gao F, Cai T, Hinton AO, Tian Y. Protocadherin20 promotes excitatory synaptogenesis in dorsal horn and contributes to bone cancer pain. Neuropharmacology 2013; 75:181-90. [PMID: 23911744 DOI: 10.1016/j.neuropharm.2013.07.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 07/04/2013] [Accepted: 07/15/2013] [Indexed: 01/13/2023]
Abstract
The majority of patients with metastatic bone disease experience moderate to severe pain. Bone cancer pain is usually progressive as the disease advances, and is very difficult to treat due to the poor understanding of the underlying mechanisms. Recent studies demonstrated that synaptic plasticity induces spinal cord sensitization and contributes to bone cancer pain. However, whether the synaptic plasticity is due to modifications of existing synapses or the formation of new synaptic connections is still unknown. Here we showed that a carcinoma implantation into a rats' tibia induced a significant increase in the number of excitability synapses in the dorsal horn, which contributes to the development of bone cancer pain. Previous studies identified that non-clustered protocadherins play significant roles in neuronal development and other implications in neurological disorders. In the present study, we showed that Protocadherin20 was significantly increased in the dorsal horn of cancer-bearing rats, while knockdown of Protocadherin20 with RNAi lentivirus reversed bone cancer-induced pain behaviors and decreased excitatory synaptogenesis in ipsilateral dorsal horn. In an in vitro study, we showed that knockdown of Protocadherin20 inhibited neurite outgrowth and excitatory synapse formation of dorsal neurons. These findings indicate that Protocadherin20 is required for the development of bone cancer pain probably by promoting the excitability synaptogenesis.
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Affiliation(s)
- Changbin Ke
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; Department of Anesthesiology, Taihe Hospital, Hubei University of Medicine, Shiyan City, Hubei Province 442000, China
| | - Caijuan Li
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaoxia Huang
- Department of Nephrology, Taihe Hospital, Hubei University of Medicine, Shiyan City, Hubei Province 442000, China
| | - Fei Cao
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Dai Shi
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Wensheng He
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Huilian Bu
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Feng Gao
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Tiantian Cai
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Antentor Othrell Hinton
- Integrative Molecular and Biomedical Sciences Graduate Program CNRC Baylor College of Medicine, Houston, TX 77030, USA
| | - Yuke Tian
- Department of Anesthesiology and Pain Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
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