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Lee S, Kim J, Ryu HH, Jang H, Lee D, Lee S, Song JM, Lee YS, Ho Suh Y. SHP2 regulates GluA2 tyrosine phosphorylation required for AMPA receptor endocytosis and mGluR-LTD. Proc Natl Acad Sci U S A 2024; 121:e2316819121. [PMID: 38657042 PMCID: PMC11066993 DOI: 10.1073/pnas.2316819121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 03/29/2024] [Indexed: 04/26/2024] Open
Abstract
Posttranslational modifications regulate the properties and abundance of synaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors that mediate fast excitatory synaptic transmission and synaptic plasticity in the central nervous system. During long-term depression (LTD), protein tyrosine phosphatases (PTPs) dephosphorylate tyrosine residues in the C-terminal tail of AMPA receptor GluA2 subunit, which is essential for GluA2 endocytosis and group I metabotropic glutamate receptor (mGluR)-dependent LTD. However, as a selective downstream effector of mGluRs, the mGluR-dependent PTP responsible for GluA2 tyrosine dephosphorylation remains elusive at Schaffer collateral (SC)-CA1 synapses. In the present study, we find that mGluR5 stimulation activates Src homology 2 (SH2) domain-containing phosphatase 2 (SHP2) by increasing phospho-Y542 levels in SHP2. Under steady-state conditions, SHP2 plays a protective role in stabilizing phospho-Y869 of GluA2 by directly interacting with GluA2 phosphorylated at Y869, without affecting GluA2 phospho-Y876 levels. Upon mGluR5 stimulation, SHP2 dephosphorylates GluA2 at Y869 and Y876, resulting in GluA2 endocytosis and mGluR-LTD. Our results establish SHP2 as a downstream effector of mGluR5 and indicate a dual action of SHP2 in regulating GluA2 tyrosine phosphorylation and function. Given the implications of mGluR5 and SHP2 in synaptic pathophysiology, we propose SHP2 as a promising therapeutic target for neurodevelopmental and autism spectrum disorders.
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Affiliation(s)
- Sanghyeon Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul03080, South Korea
- Neuroscience Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
- Transplantation Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
| | - Jungho Kim
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul03080, South Korea
- Neuroscience Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
- Transplantation Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
| | - Hyun-Hee Ryu
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul03080, South Korea
- Neuroscience Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
- Department of Physiology, Seoul National University College of Medicine, Seoul03080, South Korea
| | - Hanbyul Jang
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul03080, South Korea
- Neuroscience Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
- Department of Physiology, Seoul National University College of Medicine, Seoul03080, South Korea
| | - DoEun Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul03080, South Korea
- Neuroscience Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
- Transplantation Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
| | - Seungha Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul03080, South Korea
- Neuroscience Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
- Transplantation Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
| | - Jae-man Song
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul03080, South Korea
- Neuroscience Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
- Transplantation Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
| | - Yong-Seok Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul03080, South Korea
- Neuroscience Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
- Department of Physiology, Seoul National University College of Medicine, Seoul03080, South Korea
| | - Young Ho Suh
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul03080, South Korea
- Neuroscience Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
- Transplantation Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul03080, South Korea
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2
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Braun DJ, Frazier HN, Davis VA, Coleman MJ, Rogers CB, Van Eldik LJ. Early chronic suppression of microglial p38α in a model of Alzheimer's disease does not significantly alter amyloid-associated neuropathology. PLoS One 2023; 18:e0286495. [PMID: 37256881 PMCID: PMC10231773 DOI: 10.1371/journal.pone.0286495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 05/17/2023] [Indexed: 06/02/2023] Open
Abstract
The p38 alpha mitogen-activated protein kinase (p38α) is linked to both innate and adaptive immune responses and is under investigation as a target for drug development in the context of Alzheimer's disease (AD) and other conditions with neuroinflammatory dysfunction. While preclinical data has shown that p38α inhibition can protect against AD-associated neuropathology, the underlying mechanisms are not fully elucidated. Inhibitors of p38α may provide benefit via modulation of microglial-associated neuroinflammatory responses that contribute to AD pathology. The present study tests this hypothesis by knocking out microglial p38α and assessing early-stage pathological changes. Conditional knockout of microglial p38α was accomplished in 5-month-old C57BL/6J wild-type and amyloidogenic AD model (APPswe/PS1dE9) mice using a tamoxifen-inducible Cre/loxP system under control of the Cx3cr1 promoter. Beginning at 7.5 months of age, animals underwent behavioral assessment on the open field, followed by a later radial arm water maze test and collection of cortical and hippocampal tissues at 11 months. Additional endpoint measures included quantification of proinflammatory cytokines, assessment of amyloid burden and plaque deposition, and characterization of microglia-plaque dynamics. Loss of microglial p38α did not alter behavioral outcomes, proinflammatory cytokine levels, or overall amyloid plaque burden. However, this manipulation did significantly increase hippocampal levels of soluble Aβ42 and reduce colocalization of Iba1 and 6E10 in a subset of microglia in close proximity to plaques. The data presented here suggest that rather than reducing inflammation per se, the net effect of microglial p38α inhibition in the context of early AD-type amyloid pathology is a subtle alteration of microglia-plaque interactions. Encouragingly from a therapeutic standpoint, these data suggest no detrimental effect of even substantial decreases in microglial p38α in this context. Additionally, these results support future investigations of microglial p38α signaling at different stages of disease, as well as its relationship to phagocytic processes in this particular cell-type.
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Affiliation(s)
- David J. Braun
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, United States of America
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky, United States of America
| | - Hilaree N. Frazier
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, United States of America
| | - Verda A. Davis
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, United States of America
| | - Meggie J. Coleman
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, United States of America
| | - Colin B. Rogers
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, United States of America
| | - Linda J. Van Eldik
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky, United States of America
- Department of Neuroscience, University of Kentucky, Lexington, Kentucky, United States of America
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3
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Iba M, Kim C, Kwon S, Szabo M, Horan-Portelance L, Peer CJ, Figg WD, Reed X, Ding J, Lee SJ, Rissman RA, Cookson MR, Overk C, Wrasidlo W, Masliah E. Inhibition of p38α MAPK restores neuronal p38γ MAPK and ameliorates synaptic degeneration in a mouse model of DLB/PD. Sci Transl Med 2023; 15:eabq6089. [PMID: 37163617 DOI: 10.1126/scitranslmed.abq6089] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 04/21/2023] [Indexed: 05/12/2023]
Abstract
Alterations in the p38 mitogen-activated protein kinases (MAPKs) play an important role in the pathogenesis of dementia with Lewy bodies (DLB) and Parkinson's disease (PD). Activation of the p38α MAPK isoform and mislocalization of the p38γ MAPK isoform are associated with neuroinflammation and synaptic degeneration in DLB and PD. Therefore, we hypothesized that p38α might be associated with neuronal p38γ distribution and synaptic dysfunction in these diseases. To test this hypothesis, we treated in vitro cellular and in vivo mouse models of DLB/PD with SKF-86002, a compound that attenuates inflammation by inhibiting p38α/β, and then investigated the effects of this compound on p38γ and neurodegenerative pathology. We found that inhibition of p38α reduced neuroinflammation and ameliorated synaptic, neurodegenerative, and motor behavioral deficits in transgenic mice overexpressing human α-synuclein. Moreover, treatment with SKF-86002 promoted the redistribution of p38γ to synapses and reduced the accumulation of α-synuclein in mice overexpressing human α-synuclein. Supporting the potential value of targeting p38 in DLB/PD, we found that SKF-86002 promoted the redistribution of p38γ in neurons differentiated from iPS cells derived from patients with familial PD (carrying the A53T α-synuclein mutation) and healthy controls. Treatment with SKF-86002 ameliorated α-synuclein-induced neurodegeneration in these neurons only when microglia were pretreated with this compound. However, direct treatment of neurons with SKF-86002 did not affect α-synuclein-induced neurotoxicity, suggesting that SKF-86002 treatment inhibits α-synuclein-induced neurotoxicity mediated by microglia. These findings provide a mechanistic connection between p38α and p38γ as well as a rationale for targeting this pathway in DLB/PD.
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Affiliation(s)
- Michiyo Iba
- Laboratory of Neurogenetics, Molecular Neuropathology Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Changyoun Kim
- Laboratory of Neurogenetics, Molecular Neuropathology Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Somin Kwon
- Laboratory of Neurogenetics, Molecular Neuropathology Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marcell Szabo
- Laboratory of Neurogenetics, Molecular Neuropathology Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Liam Horan-Portelance
- Laboratory of Neurogenetics, Molecular Neuropathology Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Cody J Peer
- Clinical Pharmacology Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - William D Figg
- Clinical Pharmacology Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xylena Reed
- Laboratory of Neurogenetics, Cell Biology and Gene Expression Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jinhui Ding
- Laboratory of Neurogenetics, Computational Biology Group, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Seung-Jae Lee
- Department of Biomedical Sciences, Neuroscience Research Institute, and Department of Medicine, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Robert A Rissman
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mark R Cookson
- Laboratory of Neurogenetics, Cell Biology and Gene Expression Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
| | - Cassia Overk
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Wolf Wrasidlo
- Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Eliezer Masliah
- Laboratory of Neurogenetics, Molecular Neuropathology Section, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
- Division of Neuroscience, National Institute on Aging, National Institutes of Health, Bethesda, MD 20892, USA
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4
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Huffels CFM, Middeldorp J, Hol EM. Aß Pathology and Neuron-Glia Interactions: A Synaptocentric View. Neurochem Res 2023; 48:1026-1046. [PMID: 35976488 PMCID: PMC10030451 DOI: 10.1007/s11064-022-03699-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 06/30/2022] [Accepted: 07/15/2022] [Indexed: 10/15/2022]
Abstract
Alzheimer's disease (AD) causes the majority of dementia cases worldwide. Early pathological hallmarks include the accumulation of amyloid-ß (Aß) and activation of both astrocytes and microglia. Neurons form the building blocks of the central nervous system, and astrocytes and microglia provide essential input for its healthy functioning. Their function integrates at the level of the synapse, which is therefore sometimes referred to as the "quad-partite synapse". Increasing evidence puts AD forward as a disease of the synapse, where pre- and postsynaptic processes, as well as astrocyte and microglia functioning progressively deteriorate. Here, we aim to review the current knowledge on how Aß accumulation functionally affects the individual components of the quad-partite synapse. We highlight a selection of processes that are essential to the healthy functioning of the neuronal synapse, including presynaptic neurotransmitter release and postsynaptic receptor functioning. We further discuss how Aß affects the astrocyte's capacity to recycle neurotransmitters, release gliotransmitters, and maintain ion homeostasis. We additionally review literature on how Aß changes the immunoprotective function of microglia during AD progression and conclude by summarizing our main findings and highlighting the challenges in current studies, as well as the need for further research.
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Affiliation(s)
- Christiaan F M Huffels
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Jinte Middeldorp
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
- Department of Neurobiology & Aging, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands.
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5
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Hu Z, Ondrejcak T, Yu P, Zhang Y, Yang Y, Klyubin I, Kennelly SP, Rowan MJ, Hu NW. Do tau-synaptic long-term depression interactions in the hippocampus play a pivotal role in the progression of Alzheimer's disease? Neural Regen Res 2022; 18:1213-1219. [PMID: 36453396 PMCID: PMC9838152 DOI: 10.4103/1673-5374.360166] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Cognitive decline in Alzheimer's disease correlates with the extent of tau pathology, in particular tau hyperphosphorylation that initially appears in the transentorhinal and related regions of the brain including the hippocampus. Recent evidence indicates that tau hyperphosphorylation caused by either amyloid-β or long-term depression, a form of synaptic weakening involved in learning and memory, share similar mechanisms. Studies from our group and others demonstrate that long-term depression-inducing low-frequency stimulation triggers tau phosphorylation at different residues in the hippocampus under different experimental conditions including aging. Conversely, certain forms of long-term depression at hippocampal glutamatergic synapses require endogenous tau, in particular, phosphorylation at residue Ser396. Elucidating the exact mechanisms of interaction between tau and long-term depression may help our understanding of the physiological and pathological functions of tau/tau (hyper)phosphorylation. We first summarize experimental evidence regarding tau-long-term depression interactions, followed by a discussion of possible mechanisms by which this interplay may influence the pathogenesis of Alzheimer's disease. Finally, we conclude with some thoughts and perspectives on future research about these interactions.
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Affiliation(s)
- Zhengtao Hu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, China,Department of Gerontology, The First Affiliated Hospital of Wannan Medical College, Wuhu, Anhui Province, China
| | - Tomas Ondrejcak
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Pengpeng Yu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, China
| | - Yangyang Zhang
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, China
| | - Yin Yang
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, China,Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Igor Klyubin
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Sean P. Kennelly
- Department of Age-Related Healthcare, Tallaght University Hospital, Dublin, Ireland,Department of Medical Gerontology, Trinity College, Dublin, Ireland
| | - Michael J. Rowan
- Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland
| | - Neng-Wei Hu
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, Henan Province, China,Department of Pharmacology & Therapeutics and Institute of Neuroscience, Trinity College, Dublin, Ireland,Correspondence to: Neng-Wei Hu, .
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6
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Privitera L, Hogg EL, Lopes M, Domingos LB, Gaestel M, Müller J, Wall MJ, Corrêa SAL. The MK2 cascade mediates transient alteration in mGluR-LTD and spatial learning in a murine model of Alzheimer's disease. Aging Cell 2022; 21:e13717. [PMID: 36135933 PMCID: PMC9577942 DOI: 10.1111/acel.13717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 08/05/2022] [Accepted: 08/29/2022] [Indexed: 01/25/2023] Open
Abstract
A key aim of Alzheimer disease research is to develop efficient therapies to prevent and/or delay the irreversible progression of cognitive impairments. Early deficits in long-term potentiation (LTP) are associated with the accumulation of amyloid beta in rodent models of the disease; however, less is known about how mGluR-mediated long-term depression (mGluR-LTD) is affected. In this study, we have found that mGluR-LTD is enhanced in the APPswe /PS1dE9 mouse at 7 but returns to wild-type levels at 13 months of age. This transient over-activation of mGluR signalling is coupled with impaired LTP and shifts the dynamic range of synapses towards depression. These alterations in synaptic plasticity are associated with an inability to utilize cues in a spatial learning task. The transient dysregulation of plasticity can be prevented by genetic deletion of the MAP kinase-activated protein kinase 2 (MK2), a substrate of p38 MAPK, demonstrating that manipulating the mGluR-p38 MAPK-MK2 cascade at 7 months can prevent the shift in synapse dynamic range. Our work reveals the MK2 cascade as a potential pharmacological target to correct the over-activation of mGluR signalling.
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Affiliation(s)
- Lucia Privitera
- Bradford School of Pharmacy and Medical SciencesUniversity of BradfordBradfordUK,School of Medicine, Ninewells HospitalUniversity of DundeeDundeeUK,Barts and the London School of MedicineQueen Mary University of London Malta CampusVictoriaMalta
| | - Ellen L. Hogg
- Bradford School of Pharmacy and Medical SciencesUniversity of BradfordBradfordUK
| | - Marcia Lopes
- Bradford School of Pharmacy and Medical SciencesUniversity of BradfordBradfordUK
| | - Luana B. Domingos
- Bradford School of Pharmacy and Medical SciencesUniversity of BradfordBradfordUK
| | - Matthias Gaestel
- Institute of Cell BiochemistryHannover Medical UniversityHannoverGermany
| | - Jürgen Müller
- Bradford School of Pharmacy and Medical SciencesUniversity of BradfordBradfordUK
| | - Mark J. Wall
- School of Life SciencesUniversity of WarwickCoventryUK
| | - Sonia A. L. Corrêa
- Bradford School of Pharmacy and Medical SciencesUniversity of BradfordBradfordUK,Faculty of Science and EngineeringManchester Metropolitan UniversityManchesterUK
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Sanderson TM, Ralph LT, Amici M, Ng AN, Kaang BK, Zhuo M, Kim SJ, Georgiou J, Collingridge GL. Selective Recruitment of Presynaptic and Postsynaptic Forms of mGluR-LTD. Front Synaptic Neurosci 2022; 14:857675. [PMID: 35615440 PMCID: PMC9126322 DOI: 10.3389/fnsyn.2022.857675] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 04/20/2022] [Indexed: 12/03/2022] Open
Abstract
In area CA1 of the hippocampus, long-term depression (LTD) can be induced by activating group I metabotropic glutamate receptors (mGluRs), with the selective agonist DHPG. There is evidence that mGluR-LTD can be expressed by either a decrease in the probability of neurotransmitter release [P(r)] or by a change in postsynaptic AMPA receptor number. However, what determines the locus of expression is unknown. We investigated the expression mechanisms of mGluR-LTD using either a low (30 μM) or a high (100 μM) concentration of (RS)-DHPG. We found that 30 μM DHPG generated presynaptic LTD that required the co-activation of NMDA receptors, whereas 100 μM DHPG resulted in postsynaptic LTD that was independent of the activation of NMDA receptors. We found that both forms of LTD occur at the same synapses and that these may constitute the population with the lowest basal P(r). Our results reveal an unexpected complexity to mGluR-mediated synaptic plasticity in the hippocampus.
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Affiliation(s)
- Thomas M. Sanderson
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Liam T. Ralph
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Mascia Amici
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Ai Na Ng
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Bong-Kiun Kaang
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
- Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Min Zhuo
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Sang Jeong Kim
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - John Georgiou
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada
| | - Graham L. Collingridge
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Sinai Health System, Toronto, ON, Canada
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON, Canada
- *Correspondence: Graham L. Collingridge,
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8
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Klüssendorf M, Song I, Schau L, Morellini F, Dityatev A, Koliwer J, Kreienkamp HJ. The Golgi-Associated PDZ Domain Protein Gopc/PIST Is Required for Synaptic Targeting of mGluR5. Mol Neurobiol 2021; 58:5618-5634. [PMID: 34383253 PMCID: PMC8599212 DOI: 10.1007/s12035-021-02504-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 07/22/2021] [Indexed: 12/21/2022]
Abstract
In neuronal cells, many membrane receptors interact via their intracellular, C-terminal tails with PSD-95/discs large/ZO-1 (PDZ) domain proteins. Some PDZ proteins act as scaffold proteins. In addition, there are a few PDZ proteins such as Gopc which bind to receptors during intracellular transport. Gopc is localized at the trans-Golgi network (TGN) and binds to a variety of receptors, many of which are eventually targeted to postsynaptic sites. We have analyzed the role of Gopc by knockdown in primary cultured neurons and by generating a conditional Gopc knockout (KO) mouse line. In neurons, targeting of neuroligin 1 (Nlgn1) and metabotropic glutamate receptor 5 (mGlu5) to the plasma membrane was impaired upon depletion of Gopc, whereas NMDA receptors were not affected. In the hippocampus and cortex of Gopc KO animals, expression levels of Gopc-associated receptors were not altered, while their subcellular localization was disturbed. The targeting of mGlu5 to the postsynaptic density was reduced, coinciding with alterations in mGluR-dependent synaptic plasticity and deficiencies in a contextual fear conditioning paradigm. Our data imply Gopc in the correct subcellular sorting of its associated mGlu5 receptor in vivo.
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Affiliation(s)
- Malte Klüssendorf
- Institute for Human Genetics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Inseon Song
- Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), 39120, Magdeburg, Germany
| | - Lynn Schau
- Research Group Behavioral Biology, Center for Molecular Neurobiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Fabio Morellini
- Research Group Behavioral Biology, Center for Molecular Neurobiology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Alexander Dityatev
- Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), 39120, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), 39106, Magdeburg, Germany
- Medical Faculty, Otto-Von-Guericke University, 39120, Magdeburg, Germany
| | - Judith Koliwer
- Institute for Human Genetics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Hans-Jürgen Kreienkamp
- Institute for Human Genetics, University Medical Center Hamburg Eppendorf, Hamburg, Germany.
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9
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Tadjalli A, Seven YB, Sharma A, McCurdy CR, Bolser DC, Levitt ES, Mitchell GS. Acute morphine blocks spinal respiratory motor plasticity via long-latency mechanisms that require toll-like receptor 4 signalling. J Physiol 2021; 599:3771-3797. [PMID: 34142718 DOI: 10.1113/jp281362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 06/15/2021] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS While respiratory complications following opioid use are mainly mediated via activation of mu opioid receptors, long-latency off-target signalling via innate immune toll-like receptor 4 (TLR4) may impair other essential elements of breathing control such as respiratory motor plasticity. In adult rats, pre-treatment with a single dose of morphine blocked long-term facilitation (LTF) of phrenic motor output via a long-latency TLR4-dependent mechanism. In the phrenic motor nucleus, morphine triggered TLR4-dependent activation of microglial p38 MAPK - a key enzyme that orchestrates inflammatory signalling and is known to undermine phrenic LTF. Morphine-induced LTF loss may destabilize breathing, potentially contributing to respiratory side effects. Therefore, we suggest minimizing TLR-4 signalling may improve breathing stability during opioid therapy. ABSTRACT Opioid-induced respiratory dysfunction is a significant public health burden. While respiratory effects are mediated via mu opioid receptors, long-latency off-target opioid signalling through innate immune toll-like receptor 4 (TLR4) may modulate essential elements of breathing control, particularly respiratory motor plasticity. Plasticity in respiratory motor circuits contributes to the preservation of breathing in the face of destabilizing influences. For example, respiratory long-term facilitation (LTF), a well-studied model of respiratory motor plasticity triggered by acute intermittent hypoxia, promotes breathing stability by increasing respiratory motor drive to breathing muscles. Some forms of respiratory LTF are exquisitely sensitive to inflammation and are abolished by even a mild inflammation triggered by TLR4 activation (e.g. via systemic lipopolysaccharides). Since opioids induce inflammation and TLR4 activation, we hypothesized that opioids would abolish LTF through a TLR4-dependent mechanism. In adult Sprague Dawley rats, pre-treatment with a single systemic injection of the prototypical opioid agonist morphine blocks LTF expression several hours later in the phrenic motor system - the motor pool driving diaphragm muscle contractions. Morphine blocked phrenic LTF via TLR4-dependent mechanisms because pre-treatment with (+)-naloxone - the opioid inactive stereoisomer and novel small molecule TLR4 inhibitor - prevented impairment of phrenic LTF in morphine-treated rats. Morphine triggered TLR4-dependent activation of microglial p38 MAPK within the phrenic motor system - a key enzyme that orchestrates inflammatory signalling and undermines phrenic LTF. Morphine-induced LTF loss may destabilize breathing, potentially contributing to respiratory side effects. We suggest minimizing TLR-4 signalling may improve breathing stability during opioid therapy by restoring endogenous mechanisms of plasticity within respiratory motor circuits.
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Affiliation(s)
- Arash Tadjalli
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA.,Department of Physical Therapy, University of Florida, Gainesville, FL, USA
| | - Yasin B Seven
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA.,Department of Physical Therapy, University of Florida, Gainesville, FL, USA
| | - Abhisheak Sharma
- Department of Pharmaceutics, University of Florida, Gainesville, FL, USA
| | | | - Donald C Bolser
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA.,Department of Physiological Sciences, University of Florida, Gainesville, FL, USA
| | - Erica S Levitt
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA.,Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Gordon S Mitchell
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL, USA.,Department of Physical Therapy, University of Florida, Gainesville, FL, USA
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10
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When Good Kinases Go Rogue: GSK3, p38 MAPK and CDKs as Therapeutic Targets for Alzheimer's and Huntington's Disease. Int J Mol Sci 2021; 22:ijms22115911. [PMID: 34072862 PMCID: PMC8199025 DOI: 10.3390/ijms22115911] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 05/26/2021] [Accepted: 05/28/2021] [Indexed: 01/18/2023] Open
Abstract
Alzheimer's disease (AD) is a mostly sporadic brain disorder characterized by cognitive decline resulting from selective neurodegeneration in the hippocampus and cerebral cortex whereas Huntington's disease (HD) is a monogenic inherited disorder characterized by motor abnormalities and psychiatric disturbances resulting from selective neurodegeneration in the striatum. Although there have been numerous clinical trials for these diseases, they have been unsuccessful. Research conducted over the past three decades by a large number of laboratories has demonstrated that abnormal actions of common kinases play a key role in the pathogenesis of both AD and HD as well as several other neurodegenerative diseases. Prominent among these kinases are glycogen synthase kinase (GSK3), p38 mitogen-activated protein kinase (MAPK) and some of the cyclin-dependent kinases (CDKs). After a brief summary of the molecular and cell biology of AD and HD this review covers what is known about the role of these three groups of kinases in the brain and in the pathogenesis of the two neurodegenerative disorders. The potential of targeting GSK3, p38 MAPK and CDKS as effective therapeutics is also discussed as is a brief discussion on the utilization of recently developed drugs that simultaneously target two or all three of these groups of kinases. Multi-kinase inhibitors either by themselves or in combination with strategies currently being used such as immunotherapy or secretase inhibitors for AD and knockdown for HD could represent a more effective therapeutic approach for these fatal neurodegenerative diseases.
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11
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Urbano-Gámez JD, Casañas JJ, Benito I, Montesinos ML. Prenatal treatment with rapamycin restores enhanced hippocampal mGluR-LTD and mushroom spine size in a Down's syndrome mouse model. Mol Brain 2021; 14:84. [PMID: 34034796 PMCID: PMC8152312 DOI: 10.1186/s13041-021-00795-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 05/18/2021] [Indexed: 11/10/2022] Open
Abstract
Down syndrome (DS) is the most frequent genetic cause of intellectual disability including hippocampal-dependent memory deficits. We have previously reported hippocampal mTOR (mammalian target of rapamycin) hyperactivation, and related plasticity as well as memory deficits in Ts1Cje mice, a DS experimental model. Here we characterize the proteome of hippocampal synaptoneurosomes (SNs) from these mice, and found a predicted alteration of synaptic plasticity pathways, including long term depression (LTD). Accordingly, mGluR-LTD (metabotropic Glutamate Receptor-LTD) is enhanced in the hippocampus of Ts1Cje mice and this is correlated with an increased proportion of a particular category of mushroom spines in hippocampal pyramidal neurons. Remarkably, prenatal treatment of these mice with rapamycin has a positive pharmacological effect on both phenotypes, supporting the therapeutic potential of rapamycin/rapalogs for DS intellectual disability.
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Affiliation(s)
- Jesús David Urbano-Gámez
- Departamento de Fisiología Médica Y Biofísica, Universidad de Sevilla, Av. Sánchez-Pizjuán 4, 41009, Sevilla, Spain.,Instituto de Biomedicina de Sevilla, IBIS/Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
| | - Juan José Casañas
- Departamento de Fisiología Médica Y Biofísica, Universidad de Sevilla, Av. Sánchez-Pizjuán 4, 41009, Sevilla, Spain.,Instituto de Biomedicina de Sevilla, IBIS/Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
| | - Itziar Benito
- Departamento de Fisiología Médica Y Biofísica, Universidad de Sevilla, Av. Sánchez-Pizjuán 4, 41009, Sevilla, Spain.,Instituto de Biomedicina de Sevilla, IBIS/Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.,Servicio de Animalario, Hospital Universitario Virgen Macarena (HUVM), 41009, Sevilla, Spain
| | - María Luz Montesinos
- Departamento de Fisiología Médica Y Biofísica, Universidad de Sevilla, Av. Sánchez-Pizjuán 4, 41009, Sevilla, Spain. .,Instituto de Biomedicina de Sevilla, IBIS/Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain.
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12
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Upreti C, Woodruff CM, Zhang XL, Yim MJ, Zhou ZY, Pagano AM, Rehanian DS, Yin D, Kandel ER, Stanton PK, Nicholls RE. Loss of retinoid X receptor gamma subunit impairs group 1 mGluR mediated electrophysiological responses and group 1 mGluR dependent behaviors. Sci Rep 2021; 11:5552. [PMID: 33692389 PMCID: PMC7946894 DOI: 10.1038/s41598-021-84943-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 02/17/2021] [Indexed: 11/09/2022] Open
Abstract
Retinoid X receptors are members of the nuclear receptor family that regulate gene expression in response to retinoic acid and related ligands. Group 1 metabotropic glutamate receptors are G-protein coupled transmembrane receptors that activate intracellular signaling cascades in response to the neurotransmitter, glutamate. These two classes of molecules have been studied independently and found to play important roles in regulating neuronal physiology with potential clinical implications for disorders such as depression, schizophrenia, Parkinson's and Alzheimer's disease. Here we show that mice lacking the retinoid X receptor subunit, RXRγ, exhibit impairments in group 1 mGluR-mediated electrophysiological responses at hippocampal Schaffer collateral-CA1 pyramidal cell synapses, including impaired group 1 mGluR-dependent long-term synaptic depression (LTD), reduced group 1 mGluR-induced calcium release, and loss of group 1 mGluR-activated voltage-sensitive currents. These animals also exhibit impairments in a subset of group 1 mGluR-dependent behaviors, including motor performance, spatial object recognition, and prepulse inhibition. Together, these observations demonstrate convergence between the RXRγ and group 1 mGluR signaling pathways that may function to coordinate their regulation of neuronal activity. They also identify RXRγ as a potential target for the treatment of disorders in which group 1 mGluR signaling has been implicated.
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Affiliation(s)
- Chirag Upreti
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA
| | - Caitlin M Woodruff
- Department of Neuroscience, Columbia University, 3227 Broadway, New York, NY, 10027, USA
| | - Xiao-Lei Zhang
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA
| | - Michael J Yim
- Department of Neuroscience, Columbia University, 3227 Broadway, New York, NY, 10027, USA
| | - Zhen-Yu Zhou
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA.,Department of Neurology, New York Medical College, Valhalla, NY, 10595, USA
| | - Andrew M Pagano
- Department of Neuroscience, Columbia University, 3227 Broadway, New York, NY, 10027, USA
| | - Dina S Rehanian
- Department of Pathology and Cell Biology, Columbia University, 630 West 168thStreet, New York, NY, 10032, USA.,Taub Institute for Research on Alzheimer's Disease and Aging Brain, Columbia University, 630 West 168thStreet, New York, NY, 10032, USA
| | - Deqi Yin
- Department of Neuroscience, Columbia University, 3227 Broadway, New York, NY, 10027, USA.,Howard Hughes Medical Institute, Columbia University, 3227 Broadway, New York, NY, 10027, USA
| | - Eric R Kandel
- Department of Neuroscience, Columbia University, 3227 Broadway, New York, NY, 10027, USA.,Howard Hughes Medical Institute, Columbia University, 3227 Broadway, New York, NY, 10027, USA.,Kavli Institute for Brain Science, Columbia University, 3227 Broadway, New York, NY, 10027, USA.,Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, 3227 Broadway, New York, NY, 10027, USA
| | - Patric K Stanton
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, 10595, USA.,Department of Neurology, New York Medical College, Valhalla, NY, 10595, USA
| | - Russell E Nicholls
- Department of Pathology and Cell Biology, Columbia University, 630 West 168thStreet, New York, NY, 10032, USA. .,Taub Institute for Research on Alzheimer's Disease and Aging Brain, Columbia University, 630 West 168thStreet, New York, NY, 10032, USA.
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13
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Wong L, Chong YS, Lin W, Kisiswa L, Sim E, Ibáñez CF, Sajikumar S. Age-related changes in hippocampal-dependent synaptic plasticity and memory mediated by p75 neurotrophin receptor. Aging Cell 2021; 20:e13305. [PMID: 33448137 PMCID: PMC7884039 DOI: 10.1111/acel.13305] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 11/25/2020] [Accepted: 12/23/2020] [Indexed: 12/16/2022] Open
Abstract
The plasticity mechanisms in the nervous system that are important for learning and memory are greatly impacted during aging. Notably, hippocampal-dependent long-term plasticity and its associative plasticity, such as synaptic tagging and capture (STC), show considerable age-related decline. The p75 neurotrophin receptor (p75NTR ) is a negative regulator of structural and functional plasticity in the brain and thus represents a potential candidate to mediate age-related alterations. However, the mechanisms by which p75NTR affects synaptic plasticity of aged neuronal networks and ultimately contribute to deficits in cognitive function have not been well characterized. Here, we report that mutant mice lacking the p75NTR were resistant to age-associated changes in long-term plasticity, associative plasticity, and associative memory. Our study shows that p75NTR is responsible for age-dependent disruption of hippocampal homeostatic plasticity by modulating several signaling pathways, including BDNF, MAPK, Arc, and RhoA-ROCK2-LIMK1-cofilin. p75NTR may thus represent an important therapeutic target for limiting the age-related memory and cognitive function deficits.
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Affiliation(s)
- Lik‐Wei Wong
- Department of PhysiologyNational University of SingaporeSingapore CitySingapore
- Life Sciences Institute Neurobiology ProgrammeNational University of SingaporeSingapore CitySingapore
- Healthy Longevity Translational Research ProgrammeYong Loo Lin School of MedicineNational University of SingaporeSingapore CitySingapore
| | - Yee Song Chong
- Department of PhysiologyNational University of SingaporeSingapore CitySingapore
- Life Sciences Institute Neurobiology ProgrammeNational University of SingaporeSingapore CitySingapore
| | - Wei Lin
- Department of PhysiologyNational University of SingaporeSingapore CitySingapore
- Life Sciences Institute Neurobiology ProgrammeNational University of SingaporeSingapore CitySingapore
| | - Lilian Kisiswa
- Department of PhysiologyNational University of SingaporeSingapore CitySingapore
- Life Sciences Institute Neurobiology ProgrammeNational University of SingaporeSingapore CitySingapore
| | - Eunice Sim
- Department of PhysiologyNational University of SingaporeSingapore CitySingapore
- Life Sciences Institute Neurobiology ProgrammeNational University of SingaporeSingapore CitySingapore
| | - Carlos F. Ibáñez
- Department of PhysiologyNational University of SingaporeSingapore CitySingapore
- Life Sciences Institute Neurobiology ProgrammeNational University of SingaporeSingapore CitySingapore
- Department of NeuroscienceKarolinska InstituteStockholmSweden
| | - Sreedharan Sajikumar
- Department of PhysiologyNational University of SingaporeSingapore CitySingapore
- Life Sciences Institute Neurobiology ProgrammeNational University of SingaporeSingapore CitySingapore
- Healthy Longevity Translational Research ProgrammeYong Loo Lin School of MedicineNational University of SingaporeSingapore CitySingapore
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14
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Beamer E, Corrêa SAL. The p38 MAPK-MK2 Signaling Axis as a Critical Link Between Inflammation and Synaptic Transmission. Front Cell Dev Biol 2021; 9:635636. [PMID: 33585492 PMCID: PMC7876405 DOI: 10.3389/fcell.2021.635636] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/11/2021] [Indexed: 01/04/2023] Open
Abstract
p38 is a mitogen-activated protein kinase (MAPK), that responds primarily to stress stimuli. p38 has a number of targets for phosphorylation, including MAPK-activated protein kinase 2 (MK2). MK2 primarily functions as a master regulator of RNA-binding proteins, indirectly controlling gene expression at the level of translation. The role of MK2 in regulating the synthesis of pro-inflammatory cytokines downstream of inflammation and cellular stress is well-described. A significant amount of evidence, however, now points to a role for the p38MAPK-MK2 signaling axis in mediating synaptic plasticity through control of AMPA receptor trafficking and the morphology of dendritic spines. These processes are mediated through control of cytoskeletal dynamics via the activation of cofilin-1 and possibly control of the expression of Arc/Arg3.1. There is evidence that MK2 is necessary for group I metabotropic glutamate receptors long-term depression (mGluR-LTD). Disruption of this signaling may play an important role in mediating cognitive dysfunction in neurological disorders such as fragile X syndrome and Alzheimer’s disease. To date, the role of neuronal MK2 mediating synaptic plasticity in response to inflammatory stimuli has not yet been investigated. In immune cells, it is clear that MK2 is phosphorylated following activation of a broad range of cell surface receptors for cytokines and other inflammatory mediators. We propose that neuronal MK2 may be an important player in the link between inflammatory states and dysregulation of synaptic plasticity underlying cognitive functions. Finally, we discuss the potential of the p38MAPK-MK2 signaling axis as target for therapeutic intervention in a number of neurological disorders.
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Affiliation(s)
- Edward Beamer
- Faculty of Science and Engineering, Department of Life Sciences, Manchester Metropolitan University Manchester, Manchester, United Kingdom
| | - Sonia A L Corrêa
- Faculty of Science and Engineering, Department of Life Sciences, Manchester Metropolitan University Manchester, Manchester, United Kingdom
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15
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Tadjalli A, Seven YB, Perim RR, Mitchell GS. Systemic inflammation suppresses spinal respiratory motor plasticity via mechanisms that require serine/threonine protein phosphatase activity. J Neuroinflammation 2021; 18:28. [PMID: 33468163 PMCID: PMC7816383 DOI: 10.1186/s12974-021-02074-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 01/05/2021] [Indexed: 01/05/2023] Open
Abstract
Background Inflammation undermines multiple forms of neuroplasticity. Although inflammation and its influence on plasticity in multiple neural systems has been extensively studied, its effects on plasticity of neural networks controlling vital life functions, such as breathing, are less understood. In this study, we investigated the signaling mechanisms whereby lipopolysaccharide (LPS)-induced systemic inflammation impairs plasticity within the phrenic motor system—a major spinal respiratory motor pool that drives contractions of the diaphragm muscle. Here, we tested the hypotheses that lipopolysaccharide-induced systemic inflammation (1) blocks phrenic motor plasticity by a mechanism that requires cervical spinal okadaic acid-sensitive serine/threonine protein phosphatase (PP) 1/2A activity and (2) prevents phosphorylation/activation of extracellular signal-regulated kinase 1/2 mitogen activated protein kinase (ERK1/2 MAPK)—a key enzyme necessary for the expression of phrenic motor plasticity. Methods To study phrenic motor plasticity, we utilized a well-characterized model for spinal respiratory plasticity called phrenic long-term facilitation (pLTF). pLTF is characterized by a long-lasting, progressive enhancement of inspiratory phrenic nerve motor drive following exposures to moderate acute intermittent hypoxia (mAIH). In anesthetized, vagotomized and mechanically ventilated adult Sprague Dawley rats, we examined the effect of inhibiting cervical spinal serine/threonine PP 1/2A activity on pLTF expression in sham-vehicle and LPS-treated rats. Using immunofluorescence optical density analysis, we compared mAIH-induced phosphorylation/activation of ERK 1/2 MAPK with and without LPS-induced inflammation in identified phrenic motor neurons. Results We confirmed that mAIH-induced pLTF is abolished 24 h following low-dose systemic LPS (100 μg/kg, i.p.). Cervical spinal delivery of the PP 1/2A inhibitor, okadaic acid, restored pLTF in LPS-treated rats. LPS also prevented mAIH-induced enhancement in phrenic motor neuron ERK1/2 MAPK phosphorylation. Thus, a likely target for the relevant okadaic acid-sensitive protein phosphatases is ERK1/2 MAPK or its upstream activators. Conclusions This study increases our understanding of fundamental mechanisms whereby inflammation disrupts neuroplasticity in a critical population of motor neurons necessary for breathing, and highlights key roles for serine/threonine protein phosphatases and ERK1/2 MAPK kinase in the plasticity of mammalian spinal respiratory motor circuits.
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Affiliation(s)
- Arash Tadjalli
- Breathing Research and Therapeutics Center, Department of Physical Therapy and The McKnight Brain Institute, College of Public Health & Health Professions, University of Florida, 1225 Center Drive, PO Box 100154, Gainesville, FL, 32610, USA
| | - Yasin B Seven
- Breathing Research and Therapeutics Center, Department of Physical Therapy and The McKnight Brain Institute, College of Public Health & Health Professions, University of Florida, 1225 Center Drive, PO Box 100154, Gainesville, FL, 32610, USA
| | - Raphael R Perim
- Breathing Research and Therapeutics Center, Department of Physical Therapy and The McKnight Brain Institute, College of Public Health & Health Professions, University of Florida, 1225 Center Drive, PO Box 100154, Gainesville, FL, 32610, USA
| | - Gordon S Mitchell
- Breathing Research and Therapeutics Center, Department of Physical Therapy and The McKnight Brain Institute, College of Public Health & Health Professions, University of Florida, 1225 Center Drive, PO Box 100154, Gainesville, FL, 32610, USA.
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16
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van Gelder CAGH, Penning R, Veth TS, Catsburg LAE, Hoogenraad CC, MacGillavry HD, Altelaar M. Temporal Quantitative Proteomics of mGluR-induced Protein Translation and Phosphorylation in Neurons. Mol Cell Proteomics 2020; 19:1952-1968. [PMID: 32912969 PMCID: PMC7710149 DOI: 10.1074/mcp.ra120.002199] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/04/2020] [Indexed: 01/12/2023] Open
Abstract
At neuronal synapses, activation of group I metabotropic glutamate receptors (mGluR1/5) triggers a form of long-term depression (mGluR-LTD) that relies on new protein synthesis and the internalization of AMPA-type glutamate receptors. Dysregulation of these processes has been implicated in the development of mental disorders such as autism spectrum disorders and therefore merit a better understanding on a molecular level. Here, to study mGluR-induced signaling pathways, we integrated quantitative phosphoproteomics with the analyses of newly synthesized proteins via bio-orthogonal amino acids (azidohomoalanine) in a pulsed labeling strategy in cultured hippocampal neurons stimulated with DHPG, a specific agonist for group I mGluRs. We identified several kinases with important roles in DHPG-induced mGluR activation, which we confirmed using small molecule kinase inhibitors. Furthermore, changes in the AMPA receptor endocytosis pathway in both protein synthesis and protein phosphorylation were identified, whereby Intersectin-1 was validated as a novel player in this pathway. This study revealed several new insights into the molecular pathways downstream of group I mGluR activation in hippocampal neurons, and provides a rich resource for further analyses.
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Affiliation(s)
- Charlotte A G H van Gelder
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands; Netherlands Proteomics Center, Utrecht, The Netherlands
| | - Renske Penning
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands; Netherlands Proteomics Center, Utrecht, The Netherlands
| | - Tim S Veth
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands; Netherlands Proteomics Center, Utrecht, The Netherlands
| | - Lisa A E Catsburg
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Casper C Hoogenraad
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Harold D MacGillavry
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
| | - Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands; Netherlands Proteomics Center, Utrecht, The Netherlands.
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17
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Sharma M, Sajikumar S. G9a/GLP Complex Acts as a Bidirectional Switch to Regulate Metabotropic Glutamate Receptor-Dependent Plasticity in Hippocampal CA1 Pyramidal Neurons. Cereb Cortex 2020; 29:2932-2946. [PMID: 29982412 DOI: 10.1093/cercor/bhy161] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 06/14/2018] [Accepted: 06/17/2018] [Indexed: 02/01/2023] Open
Abstract
Metabotropic glutamate receptor-dependent long-term depression (mGluR-LTD) is conventionally considered to be solely dependent on local protein synthesis. Given the impact of epigenetics on memory, the intriguing question is whether epigenetic regulation influences mGluR-LTD as well. G9a/GLP histone lysine methyltransferase complex is crucial for brain development and goal-directed learning as well as for drug-addiction. In this study, we analyzed whether the epigenetic regulation by G9a/GLP complex affects mGluR-LTD in CA1 hippocampal pyramidal neurons of 5-7 weeks old male Wistar rats. In hippocampal slices with intact CA1 dendritic regions, inhibition of G9a/GLP activity abolished mGluR-LTD. The inhibition of this complex upregulated the expression of plasticity proteins like PKMζ, which mediated the prevention of mGluR-LTD expression by regulating the NSF-GluA2-mediated trafficking of AMPA receptors towards the postsynaptic site. G9a/GLP inhibition during the induction of mGluR-LTD also downregulated the protein levels of phosphorylated-GluA2 and Arc. Interestingly, G9a/GLP inhibition could not impede the mGluR-LTD when the cell-body was severed. Our study highlights the role of G9a/GLP complex in intact neuronal network as a bidirectional switch; when turned on, it facilitates the expression of mGluR-LTD, and when turned off, it promotes the expression of long-term potentiation.
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Affiliation(s)
- Mahima Sharma
- Department of Physiology, National University of Singapore, 2 Medical Drive, MD9, Singapore, Singapore.,Neurobiology/Aging Programme, Life Sciences Institute, Centre for Life Sciences, 28 Medical Drive, Singapore, Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, National University of Singapore, 2 Medical Drive, MD9, Singapore, Singapore.,Neurobiology/Aging Programme, Life Sciences Institute, Centre for Life Sciences, 28 Medical Drive, Singapore, Singapore
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18
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Asih PR, Prikas E, Stefanoska K, Tan ARP, Ahel HI, Ittner A. Functions of p38 MAP Kinases in the Central Nervous System. Front Mol Neurosci 2020; 13:570586. [PMID: 33013322 PMCID: PMC7509416 DOI: 10.3389/fnmol.2020.570586] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 08/18/2020] [Indexed: 12/22/2022] Open
Abstract
Mitogen-activated protein (MAP) kinases are a central component in signaling networks in a multitude of mammalian cell types. This review covers recent advances on specific functions of p38 MAP kinases in cells of the central nervous system. Unique and specific functions of the four mammalian p38 kinases are found in all major cell types in the brain. Mechanisms of p38 activation and downstream phosphorylation substrates in these different contexts are outlined and how they contribute to functions of p38 in physiological and under disease conditions. Results in different model organisms demonstrated that p38 kinases are involved in cognitive functions, including functions related to anxiety, addiction behavior, neurotoxicity, neurodegeneration, and decision making. Finally, the role of p38 kinases in psychiatric and neurological conditions and the current progress on therapeutic inhibitors targeting p38 kinases are covered and implicate p38 kinases in a multitude of CNS-related physiological and disease states.
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Affiliation(s)
- Prita R Asih
- Dementia Research Centre, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Emmanuel Prikas
- Dementia Research Centre, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Kristie Stefanoska
- Dementia Research Centre, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Amanda R P Tan
- Dementia Research Centre, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Holly I Ahel
- Dementia Research Centre, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Arne Ittner
- Dementia Research Centre, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
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19
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Chemogenetic Activation of Excitatory Neurons Alters Hippocampal Neurotransmission in a Dose-Dependent Manner. eNeuro 2019; 6:ENEURO.0124-19.2019. [PMID: 31645362 PMCID: PMC6860986 DOI: 10.1523/eneuro.0124-19.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 09/26/2019] [Accepted: 09/30/2019] [Indexed: 11/21/2022] Open
Abstract
Designer receptors exclusively activated by designer drugs (DREADD)-based chemogenetic tools are extensively used to manipulate neuronal activity in a cell type-specific manner. Whole-cell patch-clamp recordings indicate membrane depolarization, coupled with increased neuronal firing rate, following administration of the DREADD ligand, clozapine-N-oxide (CNO) to activate the Gq-coupled DREADD, hM3Dq. Although hM3Dq has been used to enhance neuronal firing in order to manipulate diverse behaviors, often within 30 min to 1 h after CNO administration, the physiological effects on excitatory neurotransmission remain poorly understood. We investigated the influence of CNO-mediated hM3Dq DREADD activation on distinct aspects of hippocampal excitatory neurotransmission at the Schaffer collateral-CA1 synapse in hippocampal slices derived from mice expressing hM3Dq in Ca2+/calmodulin-dependent protein kinase α (CamKIIα)-positive excitatory neurons. Our results indicate a clear dose-dependent effect on field EPSP (fEPSP) slope, with no change noted at the lower dose of CNO (1 µM) and a significant, long-term decline in fEPSP slope observed at higher doses (5-20 µM). Further, we noted a robust θ burst stimulus (TBS) induced long-term potentiation (LTP) in the presence of the lower CNO (1 µM) dose, which was significantly attenuated at the higher CNO (20 µM) dose. Whole-cell patch-clamp recording revealed both complex dose-dependent regulation of excitability, and spontaneous and evoked activity of CA1 pyramidal neurons in response to hM3Dq activation across CNO concentrations. Our data indicate that CNO-mediated activation of the hM3Dq DREADD results in dose-dependent regulation of excitatory hippocampal neurotransmission and highlight the importance of careful interpretation of behavioral experiments involving chemogenetic manipulation.
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Privitera L, Hogg EL, Gaestel M, Wall MJ, Corrêa SAL. The MK2 cascade regulates mGluR-dependent synaptic plasticity and reversal learning. Neuropharmacology 2019; 155:121-130. [PMID: 31129151 DOI: 10.1016/j.neuropharm.2019.05.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 05/17/2019] [Accepted: 05/18/2019] [Indexed: 12/29/2022]
Abstract
The ability to either erase or update the memories of a previously learned spatial task is an essential process that is required to modify behaviour in a changing environment. Current evidence suggests that the neural representation of such cognitive flexibility involves the balancing of synaptic potentiation (acquisition of memories) with synaptic depression (modulation and updating previously acquired memories). Here we demonstrate that the p38 MAPK/MAPK-activated protein kinase 2 (MK2) cascade is required to maintain the precise tuning of long-term potentiation and long-term depression at CA1 synapses of the hippocampus which is correlated with efficient reversal learning. Using the MK2 knockout (KO) mouse, we show that mGluR-LTD, but not NMDAR-LTD, is markedly impaired in mice aged between 4 and 5 weeks (juvenile) to 7 months (mature adult). Although the amplitude of LTP was the same as in wildtype mice, priming of LTP by the activation of group I metabotropic receptors was impaired in MK2 KO mice. Consistent with unaltered LTP amplitude and compromised mGluR-LTD, MK2 KO mice had intact spatial learning when performing the Barnes maze task, but showed specific deficits in selecting the most efficient combination of search strategies to perform the task reversal. Findings from this study suggest that the mGluR-p38-MK2 cascade is important for cognitive flexibility by regulating LTD amplitude and the priming of LTP.
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Affiliation(s)
- Lucia Privitera
- (a)Bradford School of Pharmacy and Medical Sciences, University of Bradford, Bradford, BD7 1DP, United Kingdom
| | - Ellen L Hogg
- (a)Bradford School of Pharmacy and Medical Sciences, University of Bradford, Bradford, BD7 1DP, United Kingdom
| | - Matthias Gaestel
- Institute of Cell Biochemistry, Hannover Medical University, 30625, Hannover, Germany
| | - Mark J Wall
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Sonia A L Corrêa
- (a)Bradford School of Pharmacy and Medical Sciences, University of Bradford, Bradford, BD7 1DP, United Kingdom.
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Yousef M, Babür E, Delibaş S, Tan B, Çimen A, Dursun N, Süer C. Adult-Onset Hypothyroidism Alters the Metaplastic Properties of Dentate Granule Cells by Decreasing Akt Phosphorylation. J Mol Neurosci 2019; 68:647-657. [PMID: 31069661 DOI: 10.1007/s12031-019-01323-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 04/22/2019] [Indexed: 12/15/2022]
Abstract
The expression of homosynaptic long-term depression (LTD) governs the subsequent induction of long-term potentiation (LTP) at hippocampal synapses. This process, called metaplasticity, is associated with a transient increase in the levels of several kinases, such as extracellular signal-regulated protein kinases 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and Akt kinase. It has been increasingly realized that the chemical changes in the hippocampus caused by hypothyroidism may be the key underlying causes of the learning deficits, memory loss, and impaired LTP associated with this disease. However, the functional role of thyroid hormones in the "plasticity of synaptic plasticity" has only begun to be elucidated. To address this issue, we sought to determine whether the administration of 6-n-propyl-2-thiouracil (PTU) alters the relationship between priming and the induction of subsequent LTP and related signaling molecules. The activation of ERK1/2, JNK, and Akt was measured in the hippocampus at least 95 min after priming onset. We found that priming stimulation at 5 Hz for 3 s negatively impacted the induction of LTP by subsequent tetanic stimulation in hypothyroid animals, as manifested by a more rapid decrease in the fEPSP slope and population spike amplitude. This phenomenon was accompanied by lower levels of phosphorylated Akt in the surgically removed hippocampus of the hypothyroid rats compared to the euthyroid rats. The metaplastic response and the expression of these proteins in the 1-Hz-primed hippocampus were not different between the two groups. These observations suggest that decreased PI3K/Akt signaling may be involved in the compromised metaplastic regulation of LTP observed in hypothyroidism, which may account for the learning difficulties/cognitive impairments associated with this condition.
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Affiliation(s)
- Marwa Yousef
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Ercan Babür
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Sumeyra Delibaş
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Burak Tan
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Ayşenur Çimen
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Nurcan Dursun
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Cem Süer
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey.
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Cahill EN, Milton AL. Neurochemical and molecular mechanisms underlying the retrieval-extinction effect. Psychopharmacology (Berl) 2019; 236:111-132. [PMID: 30656364 PMCID: PMC6373198 DOI: 10.1007/s00213-018-5121-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 11/12/2018] [Indexed: 12/26/2022]
Abstract
Extinction within the reconsolidation window, or 'retrieval-extinction', has received much research interest as a possible technique for targeting the reconsolidation of maladaptive memories with a behavioural intervention. However, it remains to be determined whether the retrieval-extinction effect-a long-term reduction in fear behaviour, which appears resistant to spontaneous recovery, renewal and reinstatement-depends specifically on destabilisation of the original memory (the 'reconsolidation-update' account) or represents facilitation of an extinction memory (the 'extinction-facilitation' account). We propose that comparing the neurotransmitter systems, receptors and intracellular signalling pathways recruited by reconsolidation, extinction and retrieval-extinction will provide a way of distinguishing between these accounts.
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Affiliation(s)
- Emma N Cahill
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3EG, UK
| | - Amy L Milton
- Department of Psychology, University of Cambridge, Downing Site, Cambridge, CB2 3EB, UK.
- Behavioural and Clinical Neuroscience Institute, Cambridge, CB2 3EB, UK.
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Depotentiation of Long-Term Potentiation Is Associated with Epitope-Specific Tau Hyper-/Hypophosphorylation in the Hippocampus of Adult Rats. J Mol Neurosci 2018; 67:193-203. [PMID: 30498986 DOI: 10.1007/s12031-018-1224-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 11/18/2018] [Indexed: 01/19/2023]
Abstract
It is well-known that some kinases which are involved in the induction of synaptic plasticity probably modulate tau phosphorylation. However, how depression of potentiated synaptic strength contributes to tau phosphorylation is unclear because of the lack of experiments in which depotentiation of LTP was induced. Field excitatory postsynaptic potential (fEPSP) and population spike (PS) were recorded from the dentate gyrus in response to the perforant pathway stimulation. To induce LTP, high-frequency stimulation (HFS) was used, while, for depotentiation of LTP, low-frequency stimulation (LFS) consisting of 900 pulses at 1 Hz was applied 5 min after tetanization. In some experiments, a neutral protocol at 0.033 Hz was applied throughout the experiment without any induction of synaptic plasticity. One-hertz depotentiation protocol was able to decrease fEPSP slope which was previously increased by HFS, whereas no significant change in fEPSP slope and PS amplitude was observed in neutral protocol experiments. Relative to saline infusion, LTP was lower in magnitude and was more reversed by subsequent LFS in the presence of ERK1/2 inhibitor. Western blot experiments indicated that tau protein was hyperphosphorylated at ser416 epitope but rather hypophosphorylated at thr231 epitope in the whole hippocampus upon depotentiation of LTP. These changes concomitantly occurred with a notable increase in the levels of total tau and in the levels of phosphorylated form of the extracellular signal-regulated protein kinases 1 and 2 (ERK1/2). ERK1/2 inhibition resulted in a decrease in phosphorylation of tau at p416Tau when ERK1/2 was inhibited. These findings indicate that some forms of long-term plastic changes might be related with epitope-specific tau phosphorylation and ERK1/2 activation in the hippocampus. Therefore, we emphasize that tau may be crucial for physiological learning as well as Alzheimer's disease pathology.
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Lemche E. Early Life Stress and Epigenetics in Late-onset Alzheimer's Dementia: A Systematic Review. Curr Genomics 2018; 19:522-602. [PMID: 30386171 PMCID: PMC6194433 DOI: 10.2174/1389202919666171229145156] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 07/27/2017] [Accepted: 12/12/2017] [Indexed: 11/22/2022] Open
Abstract
Involvement of life stress in Late-Onset Alzheimer's Disease (LOAD) has been evinced in longitudinal cohort epidemiological studies, and endocrinologic evidence suggests involvements of catecholamine and corticosteroid systems in LOAD. Early Life Stress (ELS) rodent models have successfully demonstrated sequelae of maternal separation resulting in LOAD-analogous pathology, thereby supporting a role of insulin receptor signalling pertaining to GSK-3beta facilitated tau hyper-phosphorylation and amyloidogenic processing. Discussed are relevant ELS studies, and findings from three mitogen-activated protein kinase pathways (JNK/SAPK pathway, ERK pathway, p38/MAPK pathway) relevant for mediating environmental stresses. Further considered were the roles of autophagy impairment, neuroinflammation, and brain insulin resistance. For the meta-analytic evaluation, 224 candidate gene loci were extracted from reviews of animal studies of LOAD pathophysiological mechanisms, of which 60 had no positive results in human LOAD association studies. These loci were combined with 89 gene loci confirmed as LOAD risk genes in previous GWAS and WES. Of the 313 risk gene loci evaluated, there were 35 human reports on epigenomic modifications in terms of methylation or histone acetylation. 64 microRNA gene regulation mechanisms were published for the compiled loci. Genomic association studies support close relations of both noradrenergic and glucocorticoid systems with LOAD. For HPA involvement, a CRHR1 haplotype with MAPT was described, but further association of only HSD11B1 with LOAD found; however, association of FKBP1 and NC3R1 polymorphisms was documented in support of stress influence to LOAD. In the brain insulin system, IGF2R, INSR, INSRR, and plasticity regulator ARC, were associated with LOAD. Pertaining to compromised myelin stability in LOAD, relevant associations were found for BIN1, RELN, SORL1, SORCS1, CNP, MAG, and MOG. Regarding epigenetic modifications, both methylation variability and de-acetylation were reported for LOAD. The majority of up-to-date epigenomic findings include reported modifications in the well-known LOAD core pathology loci MAPT, BACE1, APP (with FOS, EGR1), PSEN1, PSEN2, and highlight a central role of BDNF. Pertaining to ELS, relevant loci are FKBP5, EGR1, GSK3B; critical roles of inflammation are indicated by CRP, TNFA, NFKB1 modifications; for cholesterol biosynthesis, DHCR24; for myelin stability BIN1, SORL1, CNP; pertaining to (epi)genetic mechanisms, hTERT, MBD2, DNMT1, MTHFR2. Findings on gene regulation were accumulated for BACE1, MAPK signalling, TLR4, BDNF, insulin signalling, with most reports for miR-132 and miR-27. Unclear in epigenomic studies remains the role of noradrenergic signalling, previously demonstrated by neuropathological findings of childhood nucleus caeruleus degeneration for LOAD tauopathy.
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Affiliation(s)
- Erwin Lemche
- Section of Cognitive Neuropsychiatry, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
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25
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Joffe ME, Centanni SW, Jaramillo AA, Winder DG, Conn PJ. Metabotropic Glutamate Receptors in Alcohol Use Disorder: Physiology, Plasticity, and Promising Pharmacotherapies. ACS Chem Neurosci 2018; 9:2188-2204. [PMID: 29792024 PMCID: PMC6192262 DOI: 10.1021/acschemneuro.8b00200] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Developing efficacious treatments for alcohol use disorder (AUD) has proven difficult. The insidious nature of the disease necessitates a deep understanding of its underlying biology as well as innovative approaches to ameliorate ethanol-related pathophysiology. Excessive ethanol seeking and relapse are generated by long-term changes to membrane properties, synaptic physiology, and plasticity throughout the limbic system and associated brain structures. Each of these factors can be modulated by metabotropic glutamate (mGlu) receptors, a diverse set of G protein-coupled receptors highly expressed throughout the central nervous system. Here, we discuss how different components of the mGlu receptor family modulate neurotransmission in the limbic system and other brain regions involved in AUD etiology. We then describe how these processes are dysregulated following ethanol exposure and speculate about how mGlu receptor modulation might restore such pathophysiological changes. To that end, we detail the current understanding of the behavioral pharmacology of mGlu receptor-directed drug-like molecules in animal models of AUD. Together, this review highlights the prominent position of the mGlu receptor system in the pathophysiology of AUD and provides encouragement that several classes of mGlu receptor modulators may be translated as viable treatment options.
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Affiliation(s)
- Max E. Joffe
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
| | - Samuel W. Centanni
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37212, United States
| | - Anel A. Jaramillo
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37212, United States
| | - Danny G. Winder
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37212, United States
| | - P. Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, Tennessee 37232-0697, United States
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26
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Porto RR, Dutra FD, Crestani AP, Holsinger RMD, Quillfeldt JA, Homem de Bittencourt PI, de Oliveira Alvares L. HSP70 Facilitates Memory Consolidation of Fear Conditioning through MAPK Pathway in the Hippocampus. Neuroscience 2018; 375:108-118. [PMID: 29374537 DOI: 10.1016/j.neuroscience.2018.01.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 01/09/2018] [Accepted: 01/15/2018] [Indexed: 01/08/2023]
Abstract
Heat shock proteins of the 70-kDa (HSP70) family are cytoprotective molecular chaperones that are present in neuronal cells and can be induced by a variety of homeostatically stressful situations (not only proteostatic insults), but also by synaptic activity, including learning tasks. Physiological stimuli that induce long-term memory formation are also capable of stimulating the synthesis of HSP70 through the activation of heat shock transcription factor-1 (HSF1). In this study, we investigated the influence of HSP70 on fear memory consolidation and MAPK activity. Male rats were trained in contextual fear conditioning task and HSP70 content was analyzed by western blot in the hippocampus at different time points. We observed rapid and transient elevations in HSP70 60 min following training. Double immunofluorescence with GFAP and HSP72 revealed that astrocytes were not the site for HSP72 induction by CFC training. HSP72 distribution markedly surrounded synapses between Shaffer collateral and CA1 pyramidal cells. Infusion of recombinant HSP70 (hspa1a) into the dorsal hippocampus immediately after training facilitated memory consolidation and enhanced ERK activity while decreasing the activated forms of JNK and p38 in the hippocampus. Blocking endogenous extracellular HSP70 through the administration of specific antibody did not produce any further effect on memory consolidation when applied immediately after training, suggesting that it is indeed acting intracellularly. Induction of HSP70 after fear conditioning is fast and can act as a signaling molecule, modulating MAPK downstream signaling during memory consolidation in the hippocampus, which is crucial for fear memory formation.
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Affiliation(s)
- Rossana R Porto
- Neurobiology of Memory Laboratory, Biophysics Department, Biosciences Institute, Federal University of Rio Grande do Sul, Porto Alegre, RS 91509-900, Brazil; Laboratory of Cellular Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS 90046-900, Brazil; Graduate Program in Neuroscience, Institute of Basic Health Sciences Federal University of Rio Grande do Sul, Porto Alegre, RS 90046-900, Brazil; Laboratory of Molecular Neuroscience and Dementia, Brain & Mind Centre, The University of Sydney, Camperdown, New South Wales 2050, Australia
| | - Fabrício D Dutra
- Graduate Program in Neuroscience, Institute of Basic Health Sciences Federal University of Rio Grande do Sul, Porto Alegre, RS 90046-900, Brazil
| | - Ana Paula Crestani
- Neurobiology of Memory Laboratory, Biophysics Department, Biosciences Institute, Federal University of Rio Grande do Sul, Porto Alegre, RS 91509-900, Brazil; Graduate Program in Neuroscience, Institute of Basic Health Sciences Federal University of Rio Grande do Sul, Porto Alegre, RS 90046-900, Brazil
| | - R M Damian Holsinger
- Laboratory of Molecular Neuroscience and Dementia, Brain & Mind Centre, The University of Sydney, Camperdown, New South Wales 2050, Australia
| | - Jorge A Quillfeldt
- Neurobiology of Memory Laboratory, Biophysics Department, Biosciences Institute, Federal University of Rio Grande do Sul, Porto Alegre, RS 91509-900, Brazil; Graduate Program in Neuroscience, Institute of Basic Health Sciences Federal University of Rio Grande do Sul, Porto Alegre, RS 90046-900, Brazil
| | - Paulo Ivo Homem de Bittencourt
- Laboratory of Cellular Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS 90046-900, Brazil
| | - Lucas de Oliveira Alvares
- Neurobiology of Memory Laboratory, Biophysics Department, Biosciences Institute, Federal University of Rio Grande do Sul, Porto Alegre, RS 91509-900, Brazil; Graduate Program in Neuroscience, Institute of Basic Health Sciences Federal University of Rio Grande do Sul, Porto Alegre, RS 90046-900, Brazil.
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Low-frequency stimulation induces a durable long-term depression in young adult hyperthyroid rats: the role of p38 mitogen-activated protein kinase and protein phosphatase 1. Neuroreport 2018; 27:640-6. [PMID: 27128724 DOI: 10.1097/wnr.0000000000000589] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Long-term potentiation and long-term depression (LTD) are cellular mechanisms of learning and memory in the mammalian brain. We have previously shown that adult hyperthyroid rats showed a delay in the acquisition of a place learning task and attenuated long-term potentiation. However, changes in LTD in hyperthyroidism remain unclear. Rats were administered 0.2 mg/kg/day of L-thyroxine for 21 days starting at postnatal day 40 to induce hyperthyroidism. LTD was induced in the dentate gyrus using low-frequency stimulation (LFS) of the perforant pathway. The mRNA expressions of p38 mitogen-activated protein kinase (p38-MAPK) and protein phosphatase 1 (PP1) were evaluated using a quantitative reverse transcriptase PCR. In control rats, a standard LFS protocol induced a slight depression of the population spike (PS) amplitude during the induction phase of LTD (76±13% vs. baseline), but a small potentiation of the PS amplitude was observed in the early (107±18%) and late (111±20%) phases of LTD. Interestingly, in the hyperthyroid rats, the same LFS protocol induced a reliable LTD in the dentate gyrus of the hippocampus as evidenced by a marked depression in the PS amplitude during the induction (54±6% vs. baseline) and the early phases (56±8%) of LTD. Elevated mRNA levels of p38-MAPK and PP1 were observed in the hippocampus of the LFS-treated hyperthyroid rats compared with the hippocampus of the vehicle-treated hyperthyroid rats. No significant change in p38-MAPK or PP1 mRNA expression was observed in the euthyroid rats. The present study shows that a standard LFS protocol can induce a durable depression of synaptic strength and an upregulation of PP1 and p38-MAPK mRNA in hyperthyroid rats. We conclude that hyperthyroidism can induce molecular changes associated with degeneration of the hippocampus. The relationship between the levels of thyroid hormone and dementia requires further investigation.
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Tidball P, Burn HV, Teh KL, Volianskis A, Collingridge GL, Fitzjohn SM. Differential ability of the dorsal and ventral rat hippocampus to exhibit group I metabotropic glutamate receptor-dependent synaptic and intrinsic plasticity. Brain Neurosci Adv 2017; 1. [PMID: 28413831 PMCID: PMC5390859 DOI: 10.1177/2398212816689792] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: The hippocampus is critically involved in learning and memory processes. Although once considered a relatively homogenous structure, it is now clear that the hippocampus can be divided along its longitudinal axis into functionally distinct domains, responsible for the encoding of different types of memory or behaviour. Although differences in extrinsic connectivity are likely to contribute to this functional differentiation, emerging evidence now suggests that cellular and molecular differences at the level of local hippocampal circuits may also play a role. Methods: In this study, we have used extracellular field potential recordings to compare basal input/output function and group I metabotropic glutamate receptor-dependent forms of synaptic and intrinsic plasticity in area CA1 of slices taken from the dorsal and ventral sectors of the adult rat hippocampus. Results: Using two extracellular electrodes to simultaneously record field EPSPs and population spikes, we show that dorsal and ventral hippocampal slices differ in their basal levels of excitatory synaptic transmission, paired-pulse facilitation, and EPSP-to-Spike coupling. Furthermore, we show that slices taken from the ventral hippocampus have a greater ability than their dorsal counterparts to exhibit long-term depression of synaptic transmission and EPSP-to-Spike potentiation induced by transient application of the group I mGluR agonist (RS)-3,5-dihydroxyphenylglycine. Conclusions: Together, our results provide further evidence that the information processing properties of local hippocampal circuits differ in the dorsal and ventral hippocampal sectors, and that these differences may in turn contribute to the functional differentiation that exists along the hippocampal longitudinal axis.
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Affiliation(s)
- Patrick Tidball
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Hannah V Burn
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Kai Lun Teh
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Arturas Volianskis
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Graham L Collingridge
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Stephen M Fitzjohn
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
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Kang SJ, Kaang BK. Metabotropic glutamate receptor dependent long-term depression in the cortex. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2016; 20:557-564. [PMID: 27847432 PMCID: PMC5106389 DOI: 10.4196/kjpp.2016.20.6.557] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 08/23/2016] [Accepted: 08/23/2016] [Indexed: 02/07/2023]
Abstract
Metabotropic glutamate receptor (mGluR)-dependent long-term depression (LTD), a type of synaptic plasticity, is characterized by a reduction in the synaptic response, mainly at the excitatory synapses of the neurons. The hippocampus and the cerebellum have been the most extensively studied regions in mGluR-dependent LTD, and Group 1 mGluR has been reported to be mainly involved in this synaptic LTD at excitatory synapses. However, mGluR-dependent LTD in other brain regions may be involved in the specific behaviors or diseases. In this paper, we focus on five cortical regions and review the literature that implicates their contribution to the pathogenesis of several behaviors and specific conditions associated with mGluR-dependent LTD.
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Affiliation(s)
- Sukjae Joshua Kang
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea
| | - Bong-Kiun Kaang
- Center for Neuron and Disease, Frontier Institutes of Life Science and of Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.; Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea
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30
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Mirisis AA, Alexandrescu A, Carew TJ, Kopec AM. The Contribution of Spatial and Temporal Molecular Networks in the Induction of Long-term Memory and Its Underlying Synaptic Plasticity. AIMS Neurosci 2016; 3:356-384. [PMID: 27819030 PMCID: PMC5096789 DOI: 10.3934/neuroscience.2016.3.356] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The ability to form long-lasting memories is critical to survival and thus is highly conserved across the animal kingdom. By virtue of its complexity, this same ability is vulnerable to disruption by a wide variety of neuronal traumas and pathologies. To identify effective therapies with which to treat memory disorders, it is critical to have a clear understanding of the cellular and molecular mechanisms which subserve normal learning and memory. A significant challenge to achieving this level of understanding is posed by the wide range of distinct temporal and spatial profiles of molecular signaling induced by learning-related stimuli. In this review we propose that a useful framework within which to address this challenge is to view the molecular foundation of long-lasting plasticity as composed of unique spatial and temporal molecular networks that mediate signaling both within neurons (such as via kinase signaling) as well as between neurons (such as via growth factor signaling). We propose that evaluating how cells integrate and interpret these concurrent and interacting molecular networks has the potential to significantly advance our understanding of the mechanisms underlying learning and memory formation.
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Affiliation(s)
- Anastasios A. Mirisis
- Center for Neural Science, New York University, New York, NY, USA
- Department of Biology, New York University, New York, NY, USA
| | - Anamaria Alexandrescu
- Center for Neural Science, New York University, New York, NY, USA
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, USA
| | - Thomas J. Carew
- Center for Neural Science, New York University, New York, NY, USA
| | - Ashley M. Kopec
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
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31
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Abbas AK. Protein Synthesis Inhibitors Did Not Interfere with Long-Term Depression Induced either Electrically in Juvenile Rats or Chemically in Middle-Aged Rats. PLoS One 2016; 11:e0161270. [PMID: 27517693 PMCID: PMC4982604 DOI: 10.1371/journal.pone.0161270] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/02/2016] [Indexed: 11/26/2022] Open
Abstract
In testing the hypothesis that long-term potentiation (LTP) maintenance depends on triggered protein synthesis, we found no effect of protein synthesis inhibitors (PSIs) on LTP stabilization. Similarly, some studies reported a lack of effect of PSIs on long-term depression (LTD); the lack of effect on LTD has been suggested to be resulting from the short time recordings. If this proposal were true, LTD might exhibit sensitivity to PSIs when the recording intervals were enough long. We firstly induced LTD by a standard protocol involving low frequency stimulation, which is suitable for eliciting NMDAR-LTD in CA1 area of hippocampal slices obtained from juvenile Sprague-Dawley rats. This LTD was persistent for intervals in range of 8–10 h. Treating slices with anisomycin, however, did not interfere with the magnitude and persistence of this form of LTD. The failure of anisomycin to block synaptic-LTD might be relied on the age of animal, the type of protein synthesis inhibitors and/or the inducing protocol. To verify whether those variables altogether were determinant, NMDA or DHPG was used to chemically elicit LTD recorded up to 10 h on hippocampal slices obtained from middle-aged rats. In either form of LTD, cycloheximide did not interfere with LTD stabilization. Furthermore, DHPG application did show an increase in the global protein synthesis as assayed by radiolabeled methodology indicating that though triggered protein synthesis can occur but not necessarily required for LTD expression. The findings confirm that stabilized LTD in either juvenile, or middle-aged rats can be independent of triggered protein synthesis. Although the processes responsible for the independence of LTD stabilization on the triggered protein synthesis are not yet defined, these findings raise the possibility that de novo protein synthesis is not universally necessary.
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Affiliation(s)
- Abdul-Karim Abbas
- Institute of Neuroscience and Physiology, University of Gothenburg, Box 432, SE-40530, Gothenburg, Sweden
- * E-mail:
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32
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Sanderson TM, Hogg EL, Collingridge GL, Corrêa SAL. Hippocampal metabotropic glutamate receptor long-term depression in health and disease: focus on mitogen-activated protein kinase pathways. J Neurochem 2016; 139 Suppl 2:200-214. [PMID: 26923875 DOI: 10.1111/jnc.13592] [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: 12/07/2015] [Revised: 02/16/2016] [Accepted: 02/21/2016] [Indexed: 12/16/2022]
Abstract
Group I metabotropic glutamate receptor (mGluR) dependent long-term depression (LTD) is a major form of synaptic plasticity underlying learning and memory. The molecular mechanisms involved in mGluR-LTD have been investigated intensively for the last two decades. In this 60th anniversary special issue article, we review the recent advances in determining the mechanisms that regulate the induction, transduction and expression of mGluR-LTD in the hippocampus, with a focus on the mitogen-activated protein kinase (MAPK) pathways. In particular we discuss the requirement of p38 MAPK and extracellular signal-regulated kinase 1/2 (ERK 1/2) activation. The recent advances in understanding the signaling cascades regulating mGluR-LTD are then related to the cognitive impairments observed in neurological disorders, such as fragile X syndrome and Alzheimer's disease. mGluR-LTD is a form of synaptic plasticity that impacts on memory formation. In the hippocampus mitogen-activated protein kinases (MAPKs) have been found to be important in mGluR-LTD. In this 60th anniversary special issue article, we review the independent and complementary roles of two classes of MAPK, p38 and ERK1/2 and link this to the aberrant mGluR-LTD that has an important role in diseases. This article is part of the 60th Anniversary special issue.
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Affiliation(s)
- Thomas M Sanderson
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK
| | - Ellen L Hogg
- Bradford School of Pharmacy, Faculty of Life Sciences, University of Bradford, Bradford, UK
| | - Graham L Collingridge
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK. .,Department of Physiology, University of Toronto, Toronto, Ontario, Canada. .,Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.
| | - Sonia A L Corrêa
- Bradford School of Pharmacy, Faculty of Life Sciences, University of Bradford, Bradford, UK.
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Guntupalli S, Widagdo J, Anggono V. Amyloid-β-Induced Dysregulation of AMPA Receptor Trafficking. Neural Plast 2016; 2016:3204519. [PMID: 27073700 PMCID: PMC4814684 DOI: 10.1155/2016/3204519] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 02/28/2016] [Indexed: 01/22/2023] Open
Abstract
Evidence from neuropathological, genetic, animal model, and biochemical studies has indicated that the accumulation of amyloid-beta (Aβ) is associated with, and probably induces, profound neuronal changes in brain regions critical for memory and cognition in the development of Alzheimer's disease (AD). There is considerable evidence that synapses are particularly vulnerable to AD, establishing synaptic dysfunction as one of the earliest events in pathogenesis, prior to neuronal loss. It is clear that excessive Aβ levels can disrupt excitatory synaptic transmission and plasticity, mainly due to dysregulation of the AMPA and NMDA glutamate receptors in the brain. Importantly, AMPA receptors are the principal glutamate receptors that mediate fast excitatory neurotransmission. This is essential for synaptic plasticity, a cellular correlate of learning and memory, which are the cognitive functions that are most disrupted in AD. Here we review recent advances in the field and provide insights into the molecular mechanisms that underlie Aβ-induced dysfunction of AMPA receptor trafficking. This review focuses primarily on NMDA receptor- and metabotropic glutamate receptor-mediated signaling. In particular, we highlight several mechanisms that underlie synaptic long-term depression as common signaling pathways that are hijacked by the neurotoxic effects of Aβ.
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Affiliation(s)
- Sumasri Guntupalli
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jocelyn Widagdo
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Victor Anggono
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
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34
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Li Y, Shang J, Jiang Z, Zhang L, Su X. Regulation mechanism of peptides derived from sea cucumber ( Apostichopus japonicas) for modulation of learning and memory. Food Sci Biotechnol 2016; 25:241-246. [PMID: 30263263 DOI: 10.1007/s10068-016-0035-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 06/08/2015] [Accepted: 09/14/2015] [Indexed: 10/22/2022] Open
Abstract
Peptides derived from the sea cucumber Apostichopus japonicas have immunomodulatory and antioxidant activities. Three dosage levels of peptide hydrolysates were fed to Institute of Cancer Research (ICR) mice. Standardized Y and Morris water mazes were used to determine the effects of A. japonicas peptides on learning and memory. All 3 mouse test groups showed reductions in the latency period (LP), the number of times that a mouse swam over the location of a platform (NCP), the ratio of the distance from a target quadrant to the total swimming distance (DTQ), and the time spent in the target quadrant (TTQ). Microarray analysis was then carried out and 308 genes were differentially expressed between groups, of which 235 were up and 73 were down regulated in the brains of test group animals, compared with control group animals. Expressions of genes identified in microarrays were then analyzed using qRT-PCR.
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Affiliation(s)
- Yanyan Li
- 1Jiangsu Center for Drug Screening, Jiangsu Center for Pharmacodynamics Research and Evaluation, Key Laboratory of Drug Quality Control and Pharmacovigilance of the Ministry of Education, China Pharmaceutical University, Nanjing, 210009 China
| | - Jing Shang
- 1Jiangsu Center for Drug Screening, Jiangsu Center for Pharmacodynamics Research and Evaluation, Key Laboratory of Drug Quality Control and Pharmacovigilance of the Ministry of Education, China Pharmaceutical University, Nanjing, 210009 China
| | - Zhenzhou Jiang
- 1Jiangsu Center for Drug Screening, Jiangsu Center for Pharmacodynamics Research and Evaluation, Key Laboratory of Drug Quality Control and Pharmacovigilance of the Ministry of Education, China Pharmaceutical University, Nanjing, 210009 China
| | - Luyong Zhang
- 1Jiangsu Center for Drug Screening, Jiangsu Center for Pharmacodynamics Research and Evaluation, Key Laboratory of Drug Quality Control and Pharmacovigilance of the Ministry of Education, China Pharmaceutical University, Nanjing, 210009 China
| | - Xiurong Su
- 2School of Marine Science, Ningbo University, Ningbo, 315211 China
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Hogg EL, Müller J, Corrêa SAL. Does the MK2-dependent Production of TNFα Regulate mGluR-dependent Synaptic Plasticity? Curr Neuropharmacol 2016; 14:474-80. [PMID: 27296641 PMCID: PMC4983755 DOI: 10.2174/1570159x13666150624165939] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/22/2015] [Accepted: 06/26/2015] [Indexed: 11/22/2022] Open
Abstract
The molecular mechanisms and signalling cascades that trigger the induction of group I metabotropic glutamate receptor (GI-mGluR)-dependent long-term depression (LTD) have been the subject of intensive investigation for nearly two decades. The generation of genetically modified animals has played a crucial role in elucidating the involvement of key molecules regulating the induction and maintenance of mGluR-LTD. In this review we will discuss the requirement of the newly discovered MAPKAPK-2 (MK2) and MAPKAPK-3 (MK3) signalling cascade in regulating GI-mGluR-LTD. Recently, it has been shown that the absence of MK2 impaired the induction of GI-mGluR-dependent LTD, an effect that is caused by reduced internalization of AMPA receptors (AMPAR). As the MK2 cascade directly regulates tumour necrosis factor alpha (TNFα) production, this review will examine the evidence that the release of TNFα acts to regulate glutamate receptor expression and therefore may play a functional role in the impairment of GI-mGluRdependent LTD and the cognitive deficits observed in MK2/3 double knockout animals. The strong links of increased TNFα production in both aging and neurodegenerative disease could implicate the action of MK2 in these processes.
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Affiliation(s)
| | | | - Sônia A L Corrêa
- School of Life Sciences, Bradford University, Bradford, BD18 3LX.
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36
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Coordination between Translation and Degradation Regulates Inducibility of mGluR-LTD. Cell Rep 2015; 10:1459-1466. [PMID: 25753412 PMCID: PMC4559485 DOI: 10.1016/j.celrep.2015.02.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 12/08/2014] [Accepted: 02/03/2015] [Indexed: 11/30/2022] Open
Abstract
Dendritic protein homeostasis is crucial for most forms of long-term synaptic plasticity, and its dysregulation is linked to a wide range of brain disorders. Current models of metabotropic glutamate receptor mediated long-term depression (mGluR-LTD) suggest that rapid, local synthesis of key proteins is necessary for the induction and expression of LTD. Here, we find that mGluR-LTD can be induced in the absence of translation if the proteasome is concurrently inhibited. We report that enhanced pro-teasomal degradation during the expression of mGluR-LTD depletes dendritic proteins and inhibits subsequent inductions of LTD. Moreover, proteasome inhibition can rescue mGluR-LTD in mice null for the RNA binding protein Sam68, which we show here lack mGluR-dependent translation and LTD. Our study provides mechanistic insights for how changes in dendritic protein abundance regulate mGluR-LTD induction. We propose that Sam68-mediated translation helps to counterbalance degradation, ensuring that protein levels briefly remain above a permissive threshold during LTD induction.
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37
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Mans RA, Warmus BA, Smith CC, McMahon LL. An acetylcholinesterase inhibitor, eserine, induces long-term depression at CA3-CA1 synapses in the hippocampus of adult rats. J Neurophysiol 2014; 112:2388-97. [PMID: 25143547 DOI: 10.1152/jn.00048.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Studies in humans and rodents support a role for muscarinic ACh receptor (mAChR) and nicotinic AChR in learning and memory, and both regulate hippocampal synaptic plasticity using complex and often times opposing mechanisms. Acetylcholinesterase (AChE) inhibitors are commonly prescribed to enhance cholinergic signaling in Alzheimer's disease in hopes of rescuing cognitive function, caused, in part, by degeneration of cholinergic innervation to the hippocampus and cortex. Unfortunately, therapeutic efficacy is moderate and inconsistent, perhaps due to unanticipated mechanisms. M1 mAChRs bidirectionally control synaptic strength at CA3-CA1 synapses; weak pharmacological activation using carbachol (CCh) facilitates potentiation, whereas strong agonism induces muscarinic long-term depression (mLTD) via an ERK-dependent mechanism. Here, we tested the prediction that accumulation of extracellular ACh via inhibition of AChE is sufficient to induce LTD at CA3-CA1 synapses in hippocampal slices from adult rats. Although AChE inhibition with eserine induces LTD, it unexpectedly does not share properties with mLTD induced by CCh, as reported previously. Eserine-LTD was prevented by the M3 mAChR-preferring antagonist 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (4-DAMP), and pharmacological inhibition of MEK was completely ineffective. Additionally, pharmacological inhibition of p38 MAPK prevents mLTD but has no effect on eserine-LTD. Finally, long-term expression of eserine-LTD is partially dependent on a decrease in presynaptic release probability, likely caused by tonic activation of mAChRs by the sustained increase in extracellular ACh. Thus these findings extend current literature by showing that pharmacological AChE inhibition causes a prolonged decrease in presynaptic glutamate release at CA3-CA1 synapses, in addition to inducing a likely postsynaptic form of LTD.
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Affiliation(s)
- Robert Alan Mans
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama; Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - Brian A Warmus
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Caroline C Smith
- Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama; and
| | - Lori L McMahon
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama; Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama; and
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38
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Rapid regulation of endoplasmic reticulum dynamics in dendritic spines by NMDA receptor activation. Mol Brain 2014; 7:60. [PMID: 25242397 PMCID: PMC4237958 DOI: 10.1186/s13041-014-0060-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 08/12/2014] [Indexed: 01/24/2023] Open
Abstract
Endoplasmic reticulum (ER) is motile within dendritic spines, but the mechanisms underlying its regulation are poorly understood. To address this issue, we have simultaneously imaged morphology and ER content of dendritic spines in cultured dissociated mouse hippocampal neurons. Over a 10 min period, spines were highly dynamic, with spines both increasing and decreasing in volume. ER was present in approximately 50% of spines and was also highly dynamic, with a net increase over this period of time. Inhibition of the endogenous activation of NMDA receptors resulted in a reduction in ER growth. Conversely, augmentation of the synaptic activation of NMDA receptors, by elimination of striatal-enriched protein tyrosine phosphatase (STEP), resulted in enhanced ER growth. Therefore, NMDA receptors rapidly regulate spine ER dynamics.
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39
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Eales KL, Palygin O, O'Loughlin T, Rasooli-Nejad S, Gaestel M, Müller J, Collins DR, Pankratov Y, Corrêa SAL. The MK2/3 cascade regulates AMPAR trafficking and cognitive flexibility. Nat Commun 2014; 5:4701. [PMID: 25134715 PMCID: PMC4143933 DOI: 10.1038/ncomms5701] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 07/16/2014] [Indexed: 12/26/2022] Open
Abstract
The interplay between long-term potentiation and long-term depression (LTD) is thought to be involved in learning and memory formation. One form of LTD expressed in the hippocampus is initiated by the activation of the group 1 metabotropic glutamate receptors (mGluRs). Importantly, mGluRs have been shown to be critical for acquisition of new memories and for reversal learning, processes that are thought to be crucial for cognitive flexibility. Here we provide evidence that MAPK-activated protein kinases 2 and 3 (MK2/3) regulate neuronal spine morphology, synaptic transmission and plasticity. Furthermore, mGluR-LTD is impaired in the hippocampus of MK2/3 double knockout (DKO) mice, an observation that is mirrored by deficits in endocytosis of GluA1 subunits. Consistent with compromised mGluR-LTD, MK2/3 DKO mice have distinctive deficits in hippocampal-dependent spatial reversal learning. These novel findings demonstrate that the MK2/3 cascade plays a strategic role in controlling synaptic plasticity and cognition.
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Affiliation(s)
- Katherine L Eales
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Oleg Palygin
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Thomas O'Loughlin
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | | | - Matthias Gaestel
- Institute of Biochemistry, Hannover Medical University, 30625 Hannover, Germany
| | - Jürgen Müller
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Dawn R Collins
- Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Yuriy Pankratov
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Sonia A L Corrêa
- 1] School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK [2] School of Life Sciences, University of Bradford, Bradford BD7 1DP, UK
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40
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Changes in mGlu5 receptor-dependent synaptic plasticity and coupling to homer proteins in the hippocampus of Ube3A hemizygous mice modeling angelman syndrome. J Neurosci 2014; 34:4558-66. [PMID: 24672001 DOI: 10.1523/jneurosci.1846-13.2014] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Angelman syndrome (AS) is caused by the loss of Ube3A, an ubiquitin ligase that commits specific proteins to proteasomal degradation. How this defect causes autism and other pathological phenotypes associated with AS is unknown. Long-term depression (LTD) of excitatory synaptic transmission mediated by type 5 metabotropic glutamate (mGlu5) receptors was enhanced in hippocampal slices of Ube3A(m-/p+) mice, which model AS. No changes were found in NMDA-dependent LTD induced by low-frequency stimulation. mGlu5 receptor-dependent LTD in AS mice was sensitive to the protein synthesis inhibitor anisomycin, and relied on the same signaling pathways as in wild-type mice, e.g., the mitogen-activated protein kinase (MAPK) pathway, the phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycine pathway, and protein tyrosine phosphatase. Neither the stimulation of MAPK and PI3K nor the increase in Arc (activity-regulated cytoskeleton-associated protein) levels in response to mGlu5 receptor activation were abnormal in hippocampal slices from AS mice compared with wild-type mice. mGlu5 receptor expression and mGlu1/5 receptor-mediated polyphosphoinositide hydrolysis were also unchanged in the hippocampus of AS mice. In contrast, AS mice showed a reduced expression of the short Homer protein isoform Homer 1a, and an increased coupling of mGlu5 receptors to Homer 1b/c proteins in the hippocampus. These findings support the link between Homer proteins and monogenic autism, and lay the groundwork for the use of mGlu5 receptor antagonists in AS.
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41
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Anastasio TJ. Computational identification of potential multitarget treatments for ameliorating the adverse effects of amyloid-β on synaptic plasticity. Front Pharmacol 2014; 5:85. [PMID: 24847263 PMCID: PMC4021136 DOI: 10.3389/fphar.2014.00085] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Accepted: 04/07/2014] [Indexed: 11/24/2022] Open
Abstract
The leading hypothesis on Alzheimer Disease (AD) is that it is caused by buildup of the peptide amyloid-β (Aβ), which initially causes dysregulation of synaptic plasticity and eventually causes destruction of synapses and neurons. Pharmacological efforts to limit Aβ buildup have proven ineffective, and this raises the twin challenges of understanding the adverse effects of Aβ on synapses and of suggesting pharmacological means to prevent them. The purpose of this paper is to initiate a computational approach to understanding the dysregulation by Aβ of synaptic plasticity and to offer suggestions whereby combinations of various chemical compounds could be arrayed against it. This data-driven approach confronts the complexity of synaptic plasticity by representing findings from the literature in a course-grained manner, and focuses on understanding the aggregate behavior of many molecular interactions. The same set of interactions is modeled by two different computer programs, each written using a different programming modality: one imperative, the other declarative. Both programs compute the same results over an extensive test battery, providing an essential crosscheck. Then the imperative program is used for the computationally intensive purpose of determining the effects on the model of every combination of ten different compounds, while the declarative program is used to analyze model behavior using temporal logic. Together these two model implementations offer new insights into the mechanisms by which Aβ dysregulates synaptic plasticity and suggest many drug combinations that potentially may reduce or prevent it.
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Affiliation(s)
- Thomas J Anastasio
- Department of Molecular and Integrative Physiology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign Urbana, IL, USA
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42
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Lin CW, Chen CY, Cheng SJ, Hu HT, Hsueh YP. Sarm1 deficiency impairs synaptic function and leads to behavioral deficits, which can be ameliorated by an mGluR allosteric modulator. Front Cell Neurosci 2014; 8:87. [PMID: 24744698 PMCID: PMC3978259 DOI: 10.3389/fncel.2014.00087] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 03/09/2014] [Indexed: 01/21/2023] Open
Abstract
Innate immune responses have been shown to influence brain development and function. Dysregulation of innate immunity is significantly associated with psychiatric disorders such as autism spectrum disorders and schizophrenia, which are well-known neurodevelopmental disorders. Recent studies have revealed that critical players of the innate immune response are expressed in neuronal tissues and regulate neuronal function and activity. For example, Sarm1, a negative regulator that acts downstream of Toll-like receptor (TLR) 3 and 4, is predominantly expressed in neurons. We have previously shown that Sarm1 regulates neuronal morphogenesis and the expression of inflammatory cytokines in the brain, which then affects learning ability, cognitive flexibility, and social interaction. Because impaired neuronal morphogenesis and dysregulation of cytokine expression may disrupt neuronal activity, we investigated whether Sarm1 knockdown affects the synaptic responses of neurons. We here show that reduced Sarm1 expression impairs metabotropic glutamate receptor (mGluR)-dependent long-term depression (LTD) formation but enhances N-methyl-D-aspartate receptor (NMDAR)-dependent long-term potentiation production in hippocampal CA1 neurons. The expression levels of post-synaptic proteins, including NR2a, NR1, Shank1 and Shank3, are also altered in Sarm1 knockdown mice, suggesting a role for Sarm1 in the maintenance of synaptic homeostasis. The addition of a positive allosteric modulator of mGluR5, CDPPB, ameliorates the LTD defects in slice recording and the behavioral deficits in social interaction and associative memory. These results suggest an important role for mGluR5 signaling in the function of Sarm1. In conclusion, our study demonstrates a role for Sarm1 in the regulation of synaptic plasticity. Through these mechanisms, Sarm1 knockdown results in the impairment of associative memory and social interactions in mice.
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Affiliation(s)
- Chia-Wen Lin
- Institute of Molecular Biology, Academia Sinica Taipei, Taiwan
| | - Chiung-Ya Chen
- Institute of Molecular Biology, Academia Sinica Taipei, Taiwan
| | | | - Hsiao-Tang Hu
- Institute of Molecular Biology, Academia Sinica Taipei, Taiwan ; Graduate Institute of Life Sciences, National Defense Medical Center Taipei, Taiwan
| | - Yi-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica Taipei, Taiwan ; Graduate Institute of Life Sciences, National Defense Medical Center Taipei, Taiwan
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43
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D'Amico AG, Scuderi S, Leggio GM, Castorina A, Drago F, D'Agata V. Increased hippocampal CREB phosphorylation in dopamine D3 receptor knockout mice following passive avoidance conditioning. Neurochem Res 2013; 38:2516-23. [PMID: 24100927 DOI: 10.1007/s11064-013-1164-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/23/2013] [Accepted: 09/26/2013] [Indexed: 02/06/2023]
Abstract
Dopamine D3 receptors (D3Rs) are implicated in synaptic plasticity and memory processes. Previously we have shown that D3Rs mediate inhibitory effects on learning, since D3R knockout (D 3 (-/-) ) mice display enhanced performance in the passive avoidance task (PA). Formation of new memories is known to require de novo synthesis of proteins related to synaptic function through the activation of signaling pathways including the mitogen-activated protein kinases (MAPKs) and activation of the nuclear transcription factor cAMP response element binding protein (CREB). However, there are no clear indications regarding the specific involvement of D3Rs in the activation of these signaling cascades after acquisition of PA. Therefore, in this study we assessed whether phosphorylation levels of several MAPKs, Akt and CREB were differentially affected by PA in both wild-type (WT) and D 3 (-/-) mice hippocampi. Animals were divided in Naïve, unconditioned stimulus trained, conditioned stimulus trained and conditioned animals. Phosphorylation of extracellular signal-regulated kinase 1/2 (ERK 1/2), c-Jun-N-terminal kinase (JNK) and p38, as well as of Akt and CREB were determined. Acquisition of PA significantly increased pCREB levels both in WT and D 3 (-/-) mice. The extent of PA-driven increase in pCREB levels was significantly higher in mice lacking D3Rs. Similarly, pERK 1/2 was further augmented in trained D 3 (-/-) mice as compared to trained WTs, whereas JNK and p38 phosphorylation was not affected neither by PA nor by genetic background. Finally, Akt activation was observed in D 3 (-/-) mice, but not in response to PA. In conclusion, these data supports the notion that D3Rs might modulate CREB phosphorylation after acquisition of PA, probably via activation of ERK signaling.
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Affiliation(s)
- Agata Grazia D'Amico
- Section of Anatomy and Histology, Department of Bio-Medical Sciences, University of Catania, Via S. Sofia, 87, 95123, Catania, Italy
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Chen X, Lin R, Chang L, Xu S, Wei X, Zhang J, Wang C, Anwyl R, Wang Q. Enhancement of long-term depression by soluble amyloid β protein in rat hippocampus is mediated by metabotropic glutamate receptor and involves activation of p38MAPK, STEP and caspase-3. Neuroscience 2013; 253:435-43. [PMID: 24012839 DOI: 10.1016/j.neuroscience.2013.08.054] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 08/20/2013] [Accepted: 08/27/2013] [Indexed: 10/26/2022]
Abstract
It is reported that the amyloid-β protein (Aβ)-induced impairments in synaptic plasticity coincide with memory decline and dementia. Although Aβ-induced inhibition of hippocampal long-term potentiation has been intensively investigated, the underlying mechanism of Aβ-enhanced long-term depression (LTD) is not clear. Here, we report that acute exposure of rat hippocampal slices to soluble Aβ-enhanced LTD induced by weak low-frequency stimulation (wLFS; 1Hz for 3 min, 180 pulses) in granule cells of the dentate gyrus. Application of LY341495 (a non-selective Group I/II metrabotropic glumate receptor (mGluR) antagonist) completely blocked Aβ-enhanced LTD, whereas D-AP5 (a not selective N-methyl-d-aspartate receptor (NMDAR) antagonist) had no effect on Aβ-enhanced LTD compared with controls. In addition, Aβ-enhanced LTD was occluded by pre-application of 3,5-dihydroxyphenylglycine, a Group1 mGluR (mGluR1/5) agonist, suggesting Aβ-enhanced LTD depends on mGluR1/5 but not NMDAR. We also report here that p38 mitogen-activated protein kinase (p38MAPK) inhibitor SB203580 and postsynaptic protein tyrosine phosphatase inhibitors phenylarsine oxide and sodium orthovanadate prevented the facilitatory effect of Aβ on LTD. Application of striatal-enriched protein tyrosine phosphatase (STEP) activator MG132 facilitated induction of LTD by wLFS, but did not block following Aβ-enhanced LTD induced by another wLFS. On the other hand, Aβ-enhanced LTD blocked following MG132-LTD by wLFS, suggesting Aβ-enhanced hippocampal LTD involves STEP activation. Application of either non-selective caspase inhibitor Z-VAD-FMK or caspase-3 selective inhibitor Z-DEVD-FMK prevented Aβ-enhanced LTD. However, neither the tumor necrosis factor-α converting enzyme inhibitor TAPI-2 nor the mammalian target of rapamycin inhibitor rapamycin prevented the enhancement of Aβ on LTD. Therefore, we conclude that soluble Aβ enhances LTD in the hippocampal dentate gyrus region, and the facilitatory effect of Aβ on LTD involves mGluR1/5, p38MAPK, STEP and caspase-3 activation.
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Affiliation(s)
- X Chen
- Department of Physiology, Medical School, Research Center of Behavioral Science, Ningbo University, Ningbo 315211, China
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Goh JJ, Manahan-Vaughan D. Hippocampal long-term depression in freely behaving mice requires the activation of beta-adrenergic receptors. Hippocampus 2013; 23:1299-308. [PMID: 23878012 DOI: 10.1002/hipo.22168] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 06/19/2013] [Accepted: 07/03/2013] [Indexed: 12/20/2022]
Abstract
In the intact mouse hippocampus patterned afferent stimulation does not lead to long-term depression (LTD) at Schaffer collateral (Sc)-CA1 synapses, but the same synapses express robust LTD (<24 h) if test-pulse or patterned afferent experience is coupled with novel spatial learning. This suggests that the failure of sole afferent stimulation to elicit LTD relates to the absence of neuromodulatory input related to increased arousal or novelty during learning. Locus coeruleus (LC) firing increases during novel experience, and in rats patterned stimulation of the LC together with test-pulse stimulation of Sc-CA1 synapses leads to robust LTD in vivo. This effect is mediated by beta-adrenergic receptors. Here, we explored if activation of beta-adrenergic receptors supports the expression of LTD in freely behaving mice. We also explored if beta-adrenergic receptors contribute to endogenous LTD that is expressed following spatial learning. Patterned stimulation of Sc-CA1 synapses at 3 Hz (200 pulses) resulted in short-term depression (STD). Pretreatment with isoproterenol, an agonist of beta-adrenergic receptors, resulted in robust LTD (<24 h). Test-pulse stimulation under control conditions elicited field potentials that were stable for the 24-h monitoring period. Coupling of test-pulses with a novel spatial object recognition task resulted in robust endogenous LTD (<24 h). Pretreatment with propranolol, a beta-adrenergic receptor antagonist, completely prevented endogenous LTD that was enabled by learning and prevented object recognition learning itself. These data indicate that the absence of LTD in freely behaving mice, under standard recording conditions, does not reflect an inability of mice to express LTD, rather it is due to the absence of a noradrenalin tonus. Our data also support that spatial object recognition requires beta-adrenergic receptor activation. Furthermore, LTD that is enabled by novel spatial learning critically depends on activation of beta-adrenergic receptors that are presumably activated by noradrenalin released by the LC in response to the novel experience.
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Affiliation(s)
- Jinzhong Jeremy Goh
- Department of Neurophysiology, Ruhr University Bochum, Medical Faculty, Bochum, 44780, Germany
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Sidorov MS, Auerbach BD, Bear MF. Fragile X mental retardation protein and synaptic plasticity. Mol Brain 2013; 6:15. [PMID: 23566911 PMCID: PMC3636002 DOI: 10.1186/1756-6606-6-15] [Citation(s) in RCA: 159] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 03/25/2013] [Indexed: 12/20/2022] Open
Abstract
Loss of the translational repressor FMRP causes Fragile X syndrome. In healthy neurons, FMRP modulates the local translation of numerous synaptic proteins. Synthesis of these proteins is required for the maintenance and regulation of long-lasting changes in synaptic strength. In this role as a translational inhibitor, FMRP exerts profound effects on synaptic plasticity.
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Affiliation(s)
- Michael S Sidorov
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 46-3301, USA
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Antagonists reversibly reverse chemical LTD induced by group I, group II and group III metabotropic glutamate receptors. Neuropharmacology 2013; 74:135-46. [PMID: 23542080 DOI: 10.1016/j.neuropharm.2013.03.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 02/25/2013] [Accepted: 03/07/2013] [Indexed: 11/21/2022]
Abstract
Metabotropic glutamate (mGlu) receptors are implicated in many neurological and psychiatric diseases and are the targets of therapeutic agents currently in clinical development. Their activation has diverse effects in the central nervous system (CNS) that includes an involvement in synaptic plasticity. We previously reported that the brief exposure of hippocampal slices to dihydroxyphenylglycine (DHPG) can result in a long-term depression (LTD) of excitatory synaptic transmission. Surprisingly, this LTD could be fully reversed by mGlu receptor antagonists in a manner that was itself fully reversible upon washout of the antagonist. Here, 15 years after the discovery of DHPG-LTD and its reversible reversibility, we summarise these initial findings. We then present new data on DHPG-LTD, which demonstrates that evoked epileptiform activity triggered by activation of group I mGlu receptors can also be reversibly reversed by mGlu receptor antagonists. Furthermore, we show that the phenomenon of reversible reversibility is not specific to group I mGlu receptors. We report that activation of group II mGlu receptors in the temporo-ammonic pathway (TAP) and mossy fibre pathway within the hippocampus and in the cortical input to neurons of the lateral amygdala induces an LTD that is reversed by LY341495, a group II mGlu receptor antagonist. We also show that activation of group III mGlu8 receptors induces an LTD at lateral perforant path inputs to the dentate gyrus and that this LTD is reversed by MDCPG, an mGlu8 receptor antagonist. In conclusion, we have shown that activation of representative members of each of the three groups of mGlu receptors can induce forms of LTD than can be reversed by antagonists, and that in each case washout of the antagonist is associated with the re-establishment of the LTD. This article is part of the Special Issue entitled 'Glutamate Receptor-Dependent Synaptic Plasticity'.
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Tambuyzer T, Ahmed T, Taylor CJ, Berckmans D, Balschun D, Aerts JM. System Identification of mGluR-Dependent Long-Term Depression. Neural Comput 2013; 25:650-70. [DOI: 10.1162/neco_a_00408] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Recent advances have started to uncover the underlying mechanisms of metabotropic glutamate receptor (mGluR)–dependent long-term depression (LTD). However, it is not completely clear how these mechanisms are linked, and it is believed that several crucial mechanisms remain to be revealed. In this study, we investigated whether system identification (SI) methods can be used to gain insight into the mechanisms of synaptic plasticity. SI methods have been shown to be an objective and powerful approach for describing how sensory neurons encode information about stimuli. However, to our knowledge, it is the first time that SI methods have been applied to electrophysiological brain slice recordings of synaptic plasticity responses. The results indicate that the SI approach is a valuable tool for reverse-engineering of mGluR-LTD responses. We suggest that such SI methods can aid in unraveling the complexities of synaptic function.
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Affiliation(s)
- Tim Tambuyzer
- M3-BIORES: Measure, Model and Manage Bioresponses, Department of Biosystems, Catholic University of Leuven, Leuven B-3001, Belgium
| | - Tariq Ahmed
- Laboratory for Biological Psychology, Department of Psychology, Catholic University of Leuven, Leuven B-3001, Belgium
| | - C. James Taylor
- Engineering Department, Lancaster University, Lancaster, LA1 4YR, U.K
| | - Daniel Berckmans
- M3-BIORES: Measure, Model and Manage Bioresponses, Department of Biosystems, Catholic University of Leuven, Leuven B-3001, Belgium
| | - Detlef Balschun
- Laboratory for Biological Psychology, Department of Psychology, Catholic University of Leuven, Leuven B-3001, Belgium
| | - Jean-Marie Aerts
- M3-BIORES: Measure, Model and Manage Bioresponses, Department of Biosystems, Catholic University of Leuven, Leuven, Belgium
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Goh JJ, Manahan-Vaughan D. Synaptic depression in the CA1 region of freely behaving mice is highly dependent on afferent stimulation parameters. Front Integr Neurosci 2013; 7:1. [PMID: 23355815 PMCID: PMC3555076 DOI: 10.3389/fnint.2013.00001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 01/02/2013] [Indexed: 11/13/2022] Open
Abstract
Persistent synaptic plasticity has been subjected to intense study in the decades since it was first described. Occurring in the form of long-term potentiation (LTP) and long-term depression (LTD), it shares many cellular and molecular properties with hippocampus-dependent forms of persistent memory. Recent reports of both LTP and LTD occurring endogenously under specific learning conditions provide further support that these forms of synaptic plasticity may comprise the cellular correlates of memory. Most studies of synaptic plasticity are performed using in vitro or in vivo preparations where patterned electrical stimulation of afferent fibers is implemented to induce changes in synaptic strength. This strategy has proven very effective in inducing LTP, even under in vivo conditions. LTD in vivo has proven more elusive: although LTD occurs endogenously under specific learning conditions in both rats and mice, its induction has not been successfully demonstrated with afferent electrical stimulation alone. In this study we screened a large spectrum of protocols that are known to induce LTD either in hippocampal slices or in the intact rat hippocampus, to clarify if LTD can be induced by sole afferent stimulation in the mouse CA1 region in vivo. Low frequency stimulation at 1, 2, 3, 5, 7, or 10 Hz given in the range of 100 through 1800 pulses produced, at best, short-term depression (STD) that lasted for up to 60 min. Varying the administration pattern of the stimuli (e.g., 900 pulses given twice at 5 min intervals), or changing the stimulation intensity did not improve the persistency of synaptic depression. LTD that lasts for at least 24 h occurs under learning conditions in mice. We conclude that a coincidence of factors, such as afferent activity together with neuromodulatory inputs, play a decisive role in the enablement of LTD under more naturalistic (e.g., learning) conditions.
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Affiliation(s)
- Jinzhong J Goh
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum Bochum, Germany ; International Graduate School of Neuroscience Bochum, Germany
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Kusiak AN, Selzer ME. Neuroplasticity in the spinal cord. HANDBOOK OF CLINICAL NEUROLOGY 2013; 110:23-42. [DOI: 10.1016/b978-0-444-52901-5.00003-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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