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Cały A, Ziółkowska M, Pagano R, Salamian A, Śliwińska MA, Sotoudeh N, Bernaś T, Radwanska K. Autophosphorylation of αCaMKII regulates alcohol consumption by controlling sedative effects of alcohol and alcohol-induced loss of excitatory synapses. Addict Biol 2023; 28:e13276. [PMID: 37186439 DOI: 10.1111/adb.13276] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/07/2023] [Accepted: 03/20/2023] [Indexed: 05/17/2023]
Abstract
Calcium/calmodulin-dependent kinase II (CaMKII) is a key enzyme at the glutamatergic synapses. CAMK2A gene variants have been linked with alcohol use disorder (AUD) by an unknown mechanism. Here, we looked for the link between αCaMKII autophosphorylation and the AUD aetiology. Autophosphorylation-deficient heterozygous αCaMKII mutant mice (T286A+/- ) were trained in the IntelliCages to test the role of αCaMKII activity in AUD-related behaviours. The glutamatergic synapses morphology in CeA was studied in the animals drinking alcohol using 3D electron microscopy. We found that T286A+/- mutants consumed less alcohol and were more sensitive to sedating effects of alcohol, as compared to wild-type littermates (WT). After voluntary alcohol drinking, T286A+/- mice had less excitatory synapses in the CeA, as compared to alcohol-naive animals. This change correlated with alcohol consumption was not reversed after alcohol withdrawal and not observed in WT mice. Our study suggests that αCaMKII autophosphorylation affects alcohol consumption by controlling sedative effects of alcohol and preventing synaptic loss in the individuals drinking alcohol. This finding advances our understanding of the molecular processes that regulate alcohol dependence.
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Affiliation(s)
- Anna Cały
- Laboratory of Molecular Basis of Behavior, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Magdalena Ziółkowska
- Laboratory of Molecular Basis of Behavior, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Roberto Pagano
- Laboratory of Molecular Basis of Behavior, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
- Laboratory of Molecular and Cellular Neurobiology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Ahmad Salamian
- Laboratory of Molecular Basis of Behavior, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Małgorzata A Śliwińska
- Laboratory of Imaging Tissue Structure and Function, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Narges Sotoudeh
- Laboratory of Molecular Basis of Behavior, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Tytus Bernaś
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Kasia Radwanska
- Laboratory of Molecular Basis of Behavior, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
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2
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Jorratt P, Ricny J, Leibold C, Ovsepian SV. Endogenous Modulators of NMDA Receptor Control Dendritic Field Expansion of Cortical Neurons. Mol Neurobiol 2023; 60:1440-1452. [PMID: 36462136 PMCID: PMC9899188 DOI: 10.1007/s12035-022-03147-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 11/21/2022] [Indexed: 12/05/2022]
Abstract
Impairments of N-methyl-D-aspartate receptor (NMDAR) activity have been implicated in several neuropsychiatric disorders, with pharmacological inhibition of NMDAR-mediated currents and associated neurobehavioral changes considered as a model of schizophrenia. We analyzed the effects of brief and long-term exposure of rat cortical cultures to the most prevalent endogenous modulators of NMDAR (kynurenic acid, pregnenolone sulfate, spermidine, and zinc) on neuronal viability, stimulation-induced release of glutamate, and dendritic morphology with synaptic density. Both, glutamate release and neuronal viability studies revealed no difference between the test and control groups. No differences were also observed in the number of dendritic branching and length, or density of synaptic connections and neuronal soma size. Comparison of the extent of dendritic projections and branching patterns, however, revealed enhanced distal arborization with the expansion of the dendritic area under prolonged treatment of cultures with physiological concentrations of NMDAR modulators, with differences reaching significance in spermidine and pregnenolone sulfate tests. Measurements of the density of glutamatergic synapses showed consistency across all neuronal groups, except those treated with pregnenolone sulfate, which showed a reduction of PSD-95-positive elements. Overall, our data suggest that constitutive glutamatergic activity mediated by NMDAR controls the dendritic field expansion and can influence the integrative properties of cortical neurons.
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Affiliation(s)
- Pascal Jorratt
- grid.447902.cNational Institute of Mental Health, Klecany, Czech Republic ,grid.4491.80000 0004 1937 116XThird Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Ricny
- grid.447902.cNational Institute of Mental Health, Klecany, Czech Republic
| | - Christian Leibold
- grid.5963.9Faculty of Biology and Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Saak V. Ovsepian
- grid.36316.310000 0001 0806 5472Faculty of Science and Engineering, University of Greenwich London, Chatham Maritime, Kent, ME4 4TB UK
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3
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Mohanan AG, Gunasekaran S, Jacob RS, Omkumar RV. Role of Ca2+/Calmodulin-Dependent Protein Kinase Type II in Mediating Function and Dysfunction at Glutamatergic Synapses. Front Mol Neurosci 2022; 15:855752. [PMID: 35795689 PMCID: PMC9252440 DOI: 10.3389/fnmol.2022.855752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 03/21/2022] [Indexed: 01/25/2023] Open
Abstract
Glutamatergic synapses harbor abundant amounts of the multifunctional Ca2+/calmodulin-dependent protein kinase type II (CaMKII). Both in the postsynaptic density as well as in the cytosolic compartment of postsynaptic terminals, CaMKII plays major roles. In addition to its Ca2+-stimulated kinase activity, it can also bind to a variety of membrane proteins at the synapse and thus exert spatially restricted activity. The abundance of CaMKII in glutamatergic synapse is akin to scaffolding proteins although its prominent function still appears to be that of a kinase. The multimeric structure of CaMKII also confers several functional capabilities on the enzyme. The versatility of the enzyme has prompted hypotheses proposing several roles for the enzyme such as Ca2+ signal transduction, memory molecule function and scaffolding. The article will review the multiple roles played by CaMKII in glutamatergic synapses and how they are affected in disease conditions.
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Affiliation(s)
- Archana G. Mohanan
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
| | - Sowmya Gunasekaran
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- Research Scholar, Manipal Academy of Higher Education, Manipal, India
| | - Reena Sarah Jacob
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- Research Scholar, Manipal Academy of Higher Education, Manipal, India
| | - R. V. Omkumar
- Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India
- *Correspondence: R. V. Omkumar,
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4
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Grabowska A, Sas-Nowosielska H, Wojtas B, Holm-Kaczmarek D, Januszewicz E, Yushkevich Y, Czaban I, Trzaskoma P, Krawczyk K, Gielniewski B, Martin-Gonzalez A, Filipkowski RK, Olszynski KH, Bernas T, Szczepankiewicz AA, Sliwinska MA, Kanhema T, Bramham CR, Bokota G, Plewczynski D, Wilczynski GM, Magalska A. Activation-induced chromatin reorganization in neurons depends on HDAC1 activity. Cell Rep 2022; 38:110352. [PMID: 35172152 DOI: 10.1016/j.celrep.2022.110352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 11/09/2021] [Accepted: 01/19/2022] [Indexed: 11/23/2022] Open
Abstract
Spatial chromatin organization is crucial for transcriptional regulation and might be particularly important in neurons since they dramatically change their transcriptome in response to external stimuli. We show that stimulation of neurons causes condensation of large chromatin domains. This phenomenon can be observed in vitro in cultured rat hippocampal neurons as well as in vivo in the amygdala and hippocampal neurons. Activity-induced chromatin condensation is an active, rapid, energy-dependent, and reversible process. It involves calcium-dependent pathways but is independent of active transcription. It is accompanied by the redistribution of posttranslational histone modifications and rearrangements in the spatial organization of chromosome territories. Moreover, it leads to the reorganization of nuclear speckles and active domains located in their proximity. Finally, we find that the histone deacetylase HDAC1 is the key regulator of this process. Our results suggest that HDAC1-dependent chromatin reorganization constitutes an important level of transcriptional regulation in neurons.
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Affiliation(s)
- Agnieszka Grabowska
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Hanna Sas-Nowosielska
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Bartosz Wojtas
- Laboratory of Sequencing, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Dagmara Holm-Kaczmarek
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Elzbieta Januszewicz
- Laboratory of Molecular and Systemic Neuromorphology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Yana Yushkevich
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Iwona Czaban
- Laboratory of Molecular and Systemic Neuromorphology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Pawel Trzaskoma
- Laboratory of Molecular and Systemic Neuromorphology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Katarzyna Krawczyk
- Laboratory of Molecular and Systemic Neuromorphology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Bartlomiej Gielniewski
- Laboratory of Sequencing, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Ana Martin-Gonzalez
- Laboratory of Molecular and Systemic Neuromorphology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, San Juan de Alicante, 03550 Alicante, Spain
| | - Robert Kuba Filipkowski
- Behavior and Metabolism Research Laboratory, Mossakowski Medical Research Institute, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Krzysztof Hubert Olszynski
- Behavior and Metabolism Research Laboratory, Mossakowski Medical Research Institute, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Tytus Bernas
- Laboratory of Imaging Tissue Structure and Function, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; Department of Anatomy and Neurology, VCU School of Medicine, Richmond, VA 23284, USA
| | - Andrzej Antoni Szczepankiewicz
- Laboratory of Molecular and Systemic Neuromorphology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Malgorzata Alicja Sliwinska
- Laboratory of Imaging Tissue Structure and Function, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Tambudzai Kanhema
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway; KG Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, 5020 Bergen, Norway
| | - Clive R Bramham
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway; KG Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, 5020 Bergen, Norway
| | - Grzegorz Bokota
- Centre of New Technologies, University of Warsaw, 02-097 Warsaw, Poland; Institute of Informatics, University of Warsaw, 02-097 Warsaw, Poland
| | - Dariusz Plewczynski
- Centre of New Technologies, University of Warsaw, 02-097 Warsaw, Poland; Faculty of Mathematics and Information Science, Warsaw University of Technology, 00-662 Warsaw, Poland
| | - Grzegorz Marek Wilczynski
- Laboratory of Molecular and Systemic Neuromorphology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - Adriana Magalska
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland.
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Raven F, Aton SJ. The Engram's Dark Horse: How Interneurons Regulate State-Dependent Memory Processing and Plasticity. Front Neural Circuits 2021; 15:750541. [PMID: 34588960 PMCID: PMC8473837 DOI: 10.3389/fncir.2021.750541] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 08/26/2021] [Indexed: 12/15/2022] Open
Abstract
Brain states such as arousal and sleep play critical roles in memory encoding, storage, and recall. Recent studies have highlighted the role of engram neurons-populations of neurons activated during learning-in subsequent memory consolidation and recall. These engram populations are generally assumed to be glutamatergic, and the vast majority of data regarding the function of engram neurons have focused on glutamatergic pyramidal or granule cell populations in either the hippocampus, amygdala, or neocortex. Recent data suggest that sleep and wake states differentially regulate the activity and temporal dynamics of engram neurons. Two potential mechanisms for this regulation are either via direct regulation of glutamatergic engram neuron excitability and firing, or via state-dependent effects on interneuron populations-which in turn modulate the activity of glutamatergic engram neurons. Here, we will discuss recent findings related to the roles of interneurons in state-regulated memory processes and synaptic plasticity, and the potential therapeutic implications of understanding these mechanisms.
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Affiliation(s)
| | - Sara J. Aton
- Department of Molecular, Cellular, and Developmental Biology, College of Literature, Sciences, and the Arts, University of Michigan, Ann Arbor, MI, United States
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Turek M, Banasiak K, Piechota M, Shanmugam N, Macias M, Śliwińska MA, Niklewicz M, Kowalski K, Nowak N, Chacinska A, Pokrzywa W. Muscle-derived exophers promote reproductive fitness. EMBO Rep 2021; 22:e52071. [PMID: 34288362 PMCID: PMC8339713 DOI: 10.15252/embr.202052071] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 05/08/2021] [Accepted: 05/21/2021] [Indexed: 01/18/2023] Open
Abstract
Organismal functionality and reproduction depend on metabolic rewiring and balanced energy resources. However, the crosstalk between organismal homeostasis and fecundity and the associated paracrine signaling mechanisms are still poorly understood. Using Caenorhabditis elegans, we discovered that large extracellular vesicles (known as exophers) previously found to remove damaged subcellular elements in neurons and cardiomyocytes are released by body wall muscles (BWM) to support embryonic growth. Exopher formation (exopheresis) by BWM is sex-specific and a non-cell autonomous process regulated by developing embryos in the uterus. Embryo-derived factors induce the production of exophers that transport yolk proteins produced in the BWM and ultimately deliver them to newly formed oocytes. Consequently, offspring of mothers with a high number of muscle-derived exophers grew faster. We propose that the primary role of muscular exopheresis is to stimulate reproductive capacity, thereby influencing the adaptation of worm populations to the current environmental conditions.
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Affiliation(s)
- Michał Turek
- ReMedy International Research Agenda Unit, University of Warsaw, Warsaw, Poland.,Laboratory of Mitochondrial Biogenesis, Centre of New Technologies, University of Warsaw, Warsaw, Poland.,Laboratory of Animal Molecular Physiology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Katarzyna Banasiak
- Laboratory of Protein Metabolism, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Małgorzata Piechota
- Laboratory of Protein Metabolism, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Nilesh Shanmugam
- Laboratory of Protein Metabolism, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Matylda Macias
- Core Facility, International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Małgorzata Alicja Śliwińska
- Laboratory of Imaging Tissue Structure and Function, Nencki Institute of Experimental Biology Polish Academy of Sciences, Warsaw, Poland
| | - Marta Niklewicz
- Laboratory of Protein Metabolism, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Konrad Kowalski
- Laboratory of Protein Metabolism, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Natalia Nowak
- Laboratory of Imaging Tissue Structure and Function, Nencki Institute of Experimental Biology Polish Academy of Sciences, Warsaw, Poland
| | - Agnieszka Chacinska
- ReMedy International Research Agenda Unit, University of Warsaw, Warsaw, Poland.,Laboratory of Mitochondrial Biogenesis, Centre of New Technologies, University of Warsaw, Warsaw, Poland.,IMol Polish Academy of Sciences, Warsaw, Poland
| | - Wojciech Pokrzywa
- Laboratory of Protein Metabolism, International Institute of Molecular and Cell Biology, Warsaw, Poland
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7
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Zhao Y, Yang S, Guo Q, Guo Y, Zheng Y, Ji E. Shashen-Maidong Decoction improved chronic intermittent hypoxia-induced cognitive impairment through regulating glutamatergic signaling pathway. JOURNAL OF ETHNOPHARMACOLOGY 2021; 274:114040. [PMID: 33794336 DOI: 10.1016/j.jep.2021.114040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 03/03/2021] [Accepted: 03/13/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Obstructive sleep apnea (OSA) is characterized by chronic intermittent hypoxia (CIH), which is associated with cognitive impairment. Previous study suggested CIH exposure could induce similar symptoms and signs to the clinical features of Deficiency of both Qi and Yin Syndrome (DQYS) in Traditional Chinese Medicine (TCM). Shashen-Maidong Decoction (SMD) has been applied clinically for DQYS for hundred years. However, SMD treatment could be beneficial to CIH induced cognitive impairment is still unclear. AIM OF THE STUDY Therefore, the aim of this study was to investigate the effect of SMD treatment on CIH induced cognitive impairment, and to explore the related neuroprotective mechanism. MATERIALS AND METHODS Mice were exposed to CIH for 5 weeks (8 h/day) and were orally treated with either vehicle or SMD (5.265 g/kg/day) 30 min before CIH exposure. Spatial memory was evaluated by Morris Water Maze and Y-Maze test. Synaptic morphology in hippocampus was observed by Golgi-Cox staining and Electron microscope, and NR2B-ERK signaling pathway were detected by western blotting. RESULTS Our results showed that SMD treatment improved performance in either Morris Water Maze or Y-Maze test in mice exposed to CIH, increased spine density and postsynaptic density (PSD) thickness in hippocampus. SMD treatment suppressed the over-activation of NR2B/CaMKII/SynGAP induced by CIH exposure, enhanced ERK/CREB phosphorylation and increased PSD-95 and BDNF expression. CONCLUSION SMD attenuates the CIH-induced cognitive impairment through regulating NR2B-ERK signaling pathway. Additionally, our findings provided that DQYS may be the potential therapeutic target for neurocognitive diseases in patients with OSA.
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Affiliation(s)
- Yang Zhao
- Department of Physiology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, People's Republic of China
| | - Shengchang Yang
- Department of Physiology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, People's Republic of China; Hebei Technology Innovation Center of TCM Formula Preparations, Shijiazhuang, Hebei, People's Republic of China
| | - Qiuhong Guo
- Hebei Technology Innovation Center of TCM Formula Preparations, Shijiazhuang, Hebei, People's Republic of China
| | - Yajing Guo
- Scientific Research Center, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, People's Republic of China
| | - Yuying Zheng
- Department of Physiology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, People's Republic of China
| | - Ensheng Ji
- Department of Physiology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, People's Republic of China; Hebei Technology Innovation Center of TCM Formula Preparations, Shijiazhuang, Hebei, People's Republic of China.
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8
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The role of CaMKII autophosphorylation for NMDA receptor-dependent synaptic potentiation. Neuropharmacology 2021; 193:108616. [PMID: 34051268 DOI: 10.1016/j.neuropharm.2021.108616] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/01/2021] [Accepted: 05/13/2021] [Indexed: 11/24/2022]
Abstract
Potentiation of glutamatergic synaptic transmission is thought to underlie memory. The induction of this synaptic potentiation relies on activation of NMDA receptors which allows for calcium influx into the post-synapse. A key mechanistic question for the understanding of synaptic potentiation is what signaling is activated by the calcium influx. Here, I review evidences that at mature synapses the elevated calcium levels activate primarily calcium/calmodulin-dependent kinase II (CaMKII) and cause its autophophorylation. CaMKII autophosphorylation leads to calcium-independent activity of the kinase, so that kinase signaling can outlast NMDA receptor-dependent calcium influx. Prolonged CaMKII signaling induces downstream signaling for AMPA receptor trafficking into the post-synaptic density and causes structural enlargement of the synapse. Interestingly, however, CaMKII autophosphorylation does not have such an essential role in NMDA receptor-dependent synaptic potentiation in early postnatal development and in adult dentate gyrus, where neurogenesis occurs. Additionally, in old age memory-relevant NMDA receptor-dependent synaptic plasticity appears to be due to generation of multi-innervated dendritic spines, which does not require CaMKII autophosphorylation. In conclusion, CaMKII autophosphorylation has a conditional role in the induction of NMDA receptor-dependent synaptic potentiation.
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9
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The importance of ultrastructural analysis of memory. Brain Res Bull 2021; 173:28-36. [PMID: 33984429 DOI: 10.1016/j.brainresbull.2021.04.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 04/19/2021] [Accepted: 04/22/2021] [Indexed: 11/22/2022]
Abstract
Plasticity of glutamatergic synapses in the hippocampus is believed to underlie learning and memory processes. Surprisingly, very few studies report long-lasting structural changes of synapses induced by behavioral training. It remains, therefore, unclear which synaptic changes in the hippocampus contribute to memory storage. Here, we systematically compare how long-term potentiation of synaptic transmission (LTP) (a primary form of synaptic plasticity and cellular model of memory) and behavioral training affect hippocampal glutamatergic synapses at the ultrastructural level enabled by electron microscopy. The review of the literature indicates that while LTP induces growth of dendritic spines and post-synaptic densities (PSD), that represent postsynaptic part of a glutamatergic synapse, after behavioral training there is transient (< 6 h) synaptogenesis and long-lasting (> 24 h) increase in PSD volume (without a significant change of dendritic spine volume), indicating that training-induced PSD growth may reflect long-term enhancement of synaptic functions. Additionally, formation of multi-innervated spines (MIS), is associated with long-term memory in aged mice and LTP-deficient mutant mice. Since volume of PSD, as well as atypical synapses, can be reliably observed only with electron microscopy, we argue that the ultrastructural level of analysis is required to reveal synaptic changes that are associated with long-term storage of information in the brain.
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10
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PSD-95 in CA1 Area Regulates Spatial Choice Depending on Age. J Neurosci 2021; 41:2329-2343. [PMID: 33472821 DOI: 10.1523/jneurosci.1996-20.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 10/06/2020] [Accepted: 12/21/2020] [Indexed: 11/21/2022] Open
Abstract
Cognitive processes that require spatial information rely on synaptic plasticity in the dorsal CA1 area (dCA1) of the hippocampus. Since the function of the hippocampus is impaired in aged individuals, it remains unknown how aged animals make spatial choices. Here, we used IntelliCage to study behavioral processes that support spatial choices of aged female mice living in a group. As a proxy of training-induced synaptic plasticity, we analyzed the morphology of dendritic spines and the expression of a synaptic scaffold protein, PSD-95. We observed that spatial choice training in young adult mice induced correlated shrinkage of dendritic spines and downregulation of PSD-95 in dCA1. Moreover, long-term depletion of PSD-95 by shRNA in dCA1 limited correct choices to a reward corner, while reward preference was intact. In contrast, old mice used behavioral strategies characterized by an increased tendency for perseverative visits and social interactions. This strategy resulted in a robust preference for the reward corner during the spatial choice task. Moreover, training decreased the correlation between PSD-95 expression and the size of dendritic spines. Furthermore, PSD-95 depletion did not impair place choice or reward preference in old mice. Thus, our data indicate that while young mice require PSD-95-dependent synaptic plasticity in dCA1 to make correct spatial choices, old animals observe cage mates and stick to a preferred corner to seek the reward. This strategy is resistant to the depletion of PSD-95 in the CA1 area. Overall, our study demonstrates that aged mice combine alternative behavioral and molecular strategies to approach and consume rewards in a complex environment.SIGNIFICANCE STATEMENT It remains poorly understood how aging affects behavioral and molecular processes that support cognitive functions. It is, however, essential to understand these processes to develop therapeutic interventions that support successful cognitive aging. Our data indicate that while young mice require PSD-95-dependent synaptic plasticity in dCA1 to make correct spatial choices (i.e., choices that require spatial information), old animals observe cage mates and stick to a preferred corner to seek the reward. This strategy is resistant to the depletion of PSD-95 in the CA1 area. Overall, our study demonstrates that aged mice combine alternative behavioral and molecular strategies to approach and consume rewards in a complex environment. Second, the contribution of PSD-95-dependent synaptic functions in spatial choice changes with age.
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