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Südkamp N, Shchyglo O, Manahan-Vaughan D. GluN2A or GluN2B subunits of the NMDA receptor contribute to changes in neuronal excitability and impairments in LTP in the hippocampus of aging mice but do not mediate detrimental effects of oligomeric Aβ (1-42). Front Aging Neurosci 2024; 16:1377085. [PMID: 38832073 PMCID: PMC11144909 DOI: 10.3389/fnagi.2024.1377085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 04/26/2024] [Indexed: 06/05/2024] Open
Abstract
Studies in rodent models have revealed that oligomeric beta-amyloid protein [Aβ (1-42)] plays an important role in the pathogenesis of Alzheimer's disease. Early elevations in hippocampal neuronal excitability caused by Aβ (1-42) have been proposed to be mediated via enhanced activation of GluN2B-containing N-methyl-D-aspartate receptors (NMDAR). To what extent GluN2A or GluN2B-containing NMDAR contribute to Aβ (1-42)-mediated impairments of hippocampal function in advanced rodent age is unclear. Here, we assessed hippocampal long-term potentiation (LTP) and neuronal responses 4-5 weeks after bilateral intracerebral inoculation of 8-15 month old GluN2A+/- or GluN2B+/- transgenic mice with oligomeric Aβ (1-42), or control peptide. Whole-cell patch-clamp recordings in CA1 pyramidal neurons revealed a more positive resting membrane potential and increased total spike time in GluN2A+/-, but not GluN2B+/--hippocampi following treatment with Aβ (1-42) compared to controls. Action potential 20%-width was increased, and the descending slope was reduced, in Aβ-treated GluN2A+/-, but not GluN2B+/- hippocampi. Sag ratio was increased in Aβ-treated GluN2B+/--mice. Firing frequency was unchanged in wt, GluN2A+/-, and GluN2B+/-hippocampi after Aβ-treatment. Effects were not significantly different from responses detected under the same conditions in wt littermates, however. LTP that lasted for over 2 h in wt hippocampal slices was significantly reduced in GluN2A+/- and was impaired for 15 min in GluN2B+/--hippocampi compared to wt littermates. Furthermore, LTP (>2 h) was significantly impaired in Aβ-treated hippocampi of wt littermates compared to wt treated with control peptide. LTP induced in Aβ-treated GluN2A+/- and GluN2B+/--hippocampi was equivalent to LTP in control peptide-treated transgenic and Aβ-treated wt animals. Taken together, our data indicate that knockdown of GluN2A subunits subtly alters membrane properties of hippocampal neurons and reduces the magnitude of LTP. GluN2B knockdown reduces the early phase of LTP but leaves later phases intact. Aβ (1-42)-treatment slightly exacerbates changes in action potential properties in GluN2A+/--mice. However, the vulnerability of the aging hippocampus to Aβ-mediated impairments of LTP is not mediated by GluN2A or GluN2B-containing NMDAR.
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Vieira MM, Peng S, Won S, Hong E, Inati SK, Thurm A, Thiam AH, Kim S, Myers SJ, Badger JD, Traynelis SF, Lu W, Roche KW. A Frameshift Variant of GluN2A Identified in an Epilepsy Patient Results in NMDA Receptor Mistargeting. J Neurosci 2024; 44:e0557232023. [PMID: 38050135 PMCID: PMC10860613 DOI: 10.1523/jneurosci.0557-23.2023] [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: 03/27/2023] [Revised: 08/24/2023] [Accepted: 11/14/2023] [Indexed: 12/06/2023] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) are crucial for neuronal development and synaptic plasticity. Dysfunction of NMDARs is associated with multiple neurodevelopmental disorders, including epilepsy, autism spectrum disorder, and intellectual disability. Understanding the impact of genetic variants of NMDAR subunits can shed light on the mechanisms of disease. Here, we characterized the functional implications of a de novo mutation of the GluN2A subunit (P1199Rfs*32) resulting in the truncation of the C-terminal domain. The variant was identified in a male patient with epileptic encephalopathy, multiple seizure types, severe aphasia, and neurobehavioral changes. Given the known role of the CTD in NMDAR trafficking, we examined changes in receptor localization and abundance at the postsynaptic membrane using a combination of molecular assays in heterologous cells and rat primary neuronal cultures. We observed that the GluN2A P1199Rfs*32-containing receptors traffic efficiently to the postsynaptic membrane but have increased extra-synaptic expression relative to WT GluN2A-containing NMDARs. Using in silico predictions, we hypothesized that the mutant would lose all PDZ interactions, except for the recycling protein Scribble1. Indeed, we observed impaired binding to the scaffolding protein postsynaptic protein-95 (PSD-95); however, we found the mutant interacts with Scribble1, which facilitates the recycling of both the mutant and the WT GluN2A. Finally, we found that neurons expressing GluN2A P1199Rfs*32 have fewer synapses and decreased spine density, indicating compromised synaptic transmission in these neurons. Overall, our data show that GluN2A P1199Rfs*32 is a loss-of-function variant with altered membrane localization in neurons and provide mechanistic insight into disease etiology.
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Affiliation(s)
- M M Vieira
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda 20892, Maryland
| | - S Peng
- Synapse and Neural Circuit Research Section, NINDS, NIH, Bethesda 20892, Maryland
| | - S Won
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda 20892, Maryland
| | - E Hong
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda 20892, Maryland
| | - S K Inati
- Neurophysiology of Epilepsy Unit, NINDS, NIH, Bethesda 20892, Maryland
| | - A Thurm
- National Institute of Mental Health, National Institutes of Health, Bethesda 20892, Maryland
| | - A H Thiam
- Office of the Clinical Director, NINDS, NIH, Bethesda 20892, Maryland
| | - S Kim
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta 30322, Georgia
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta 30322, Georgia
| | - S J Myers
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta 30322, Georgia
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta 30322, Georgia
| | - J D Badger
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda 20892, Maryland
| | - S F Traynelis
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta 30322, Georgia
- Center for Functional Evaluation of Rare Variants (CFERV), Emory University School of Medicine, Atlanta 30322, Georgia
| | - W Lu
- Synapse and Neural Circuit Research Section, NINDS, NIH, Bethesda 20892, Maryland
| | - K W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda 20892, Maryland
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Kysilov B, Kuchtiak V, Hrcka Krausova B, Balik A, Korinek M, Fili K, Dobrovolski M, Abramova V, Chodounska H, Kudova E, Bozikova P, Cerny J, Smejkalova T, Vyklicky L. Disease-associated nonsense and frame-shift variants resulting in the truncation of the GluN2A or GluN2B C-terminal domain decrease NMDAR surface expression and reduce potentiating effects of neurosteroids. Cell Mol Life Sci 2024; 81:36. [PMID: 38214768 PMCID: PMC10786987 DOI: 10.1007/s00018-023-05062-6] [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: 09/09/2023] [Revised: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 01/13/2024]
Abstract
N-methyl-D-aspartate receptors (NMDARs) play a critical role in normal brain function, and variants in genes encoding NMDAR subunits have been described in individuals with various neuropsychiatric disorders. We have used whole-cell patch-clamp electrophysiology, fluorescence microscopy and in-silico modeling to explore the functional consequences of disease-associated nonsense and frame-shift variants resulting in the truncation of GluN2A or GluN2B C-terminal domain (CTD). This study characterizes variant NMDARs and shows their reduced surface expression and synaptic localization, altered agonist affinity, increased desensitization, and reduced probability of channel opening. We also show that naturally occurring and synthetic steroids pregnenolone sulfate and epipregnanolone butanoic acid, respectively, enhance NMDAR function in a way that is dependent on the length of the truncated CTD and, further, is steroid-specific, GluN2A/B subunit-specific, and GluN1 splice variant-specific. Adding to the previously described effects of disease-associated NMDAR variants on the receptor biogenesis and function, our results improve the understanding of the molecular consequences of NMDAR CTD truncations and provide an opportunity for the development of new therapeutic neurosteroid-based ligands.
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Affiliation(s)
- Bohdan Kysilov
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200, Prague 4, Czech Republic
- Stony Brook University, Stony Brook, 100 Nicolls Road, NY, 11794, USA
| | - Viktor Kuchtiak
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200, Prague 4, Czech Republic
- Faculty of Science, Charles University, Albertov 2038, 12800, Prague 2, Czech Republic
| | - Barbora Hrcka Krausova
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200, Prague 4, Czech Republic
| | - Ales Balik
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200, Prague 4, Czech Republic
| | - Miloslav Korinek
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200, Prague 4, Czech Republic
| | - Klevinda Fili
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200, Prague 4, Czech Republic
- Third Faculty of Medicine, Charles University, Ruska 87, 10000, Prague 10, Czech Republic
| | - Mark Dobrovolski
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200, Prague 4, Czech Republic
- Third Faculty of Medicine, Charles University, Ruska 87, 10000, Prague 10, Czech Republic
| | - Vera Abramova
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200, Prague 4, Czech Republic
- Third Faculty of Medicine, Charles University, Ruska 87, 10000, Prague 10, Czech Republic
| | - Hana Chodounska
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Nam. 2, 16610, Prague 6, Czech Republic
| | - Eva Kudova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo Nam. 2, 16610, Prague 6, Czech Republic
| | - Paulina Bozikova
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 25250, Vestec, Czech Republic
| | - Jiri Cerny
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200, Prague 4, Czech Republic
| | - Tereza Smejkalova
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200, Prague 4, Czech Republic.
| | - Ladislav Vyklicky
- Laboratory of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14200, Prague 4, Czech Republic.
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Naylor DE. In the fast lane: Receptor trafficking during status epilepticus. Epilepsia Open 2023; 8 Suppl 1:S35-S65. [PMID: 36861477 PMCID: PMC10173858 DOI: 10.1002/epi4.12718] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 02/23/2023] [Indexed: 03/03/2023] Open
Abstract
Status epilepticus (SE) remains a significant cause of morbidity and mortality and often is refractory to standard first-line treatments. A rapid loss of synaptic inhibition and development of pharmacoresistance to benzodiazepines (BZDs) occurs early during SE, while NMDA and AMPA receptor antagonists remain effective treatments after BZDs have failed. Multimodal and subunit-selective receptor trafficking within minutes to an hour of SE involves GABA-A, NMDA, and AMPA receptors and contributes to shifts in the number and subunit composition of surface receptors with differential impacts on the physiology, pharmacology, and strength of GABAergic and glutamatergic currents at synaptic and extrasynaptic sites. During the first hour of SE, synaptic GABA-A receptors containing γ2 subunits move to the cell interior while extrasynaptic GABA-A receptors with δ subunits are preserved. Conversely, NMDA receptors containing N2B subunits are increased at synaptic and extrasynaptic sites, and homomeric GluA1 ("GluA2-lacking") calcium permeant AMPA receptor surface expression also is increased. Molecular mechanisms, largely driven by NMDA receptor or calcium permeant AMPA receptor activation early during circuit hyperactivity, regulate subunit-specific interactions with proteins involved with synaptic scaffolding, adaptin-AP2/clathrin-dependent endocytosis, endoplasmic reticulum (ER) retention, and endosomal recycling. Reviewed here is how SE-induced shifts in receptor subunit composition and surface representation increase the excitatory to inhibitory imbalance that sustains seizures and fuels excitotoxicity contributing to chronic sequela such as "spontaneous recurrent seizures" (SRS). A role for early multimodal therapy is suggested both for treatment of SE and for prevention of long-term comorbidities.
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Affiliation(s)
- David E Naylor
- VA Greater Los Angeles Healthcare System, Department of Neurology, David Geffen School of Medicine at UCLA, and The Lundquist Institute at Harbor-UCLA Medical Center, Los Angeles, California, USA
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Ramos A, Granzotto N, Kremer R, Boeder AM, de Araújo JFP, Pereira AG, Izídio GS. Hunting for Genes Underlying Emotionality in the Laboratory Rat: Maps, Tools and Traps. Curr Neuropharmacol 2023; 21:1840-1863. [PMID: 36056863 PMCID: PMC10514530 DOI: 10.2174/1570159x20666220901154034] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 06/13/2022] [Accepted: 07/28/2022] [Indexed: 11/22/2022] Open
Abstract
Scientists have systematically investigated the hereditary bases of behaviors since the 19th century, moved by either evolutionary questions or clinically-motivated purposes. The pioneer studies on the genetic selection of laboratory animals had already indicated, one hundred years ago, the immense complexity of analyzing behaviors that were influenced by a large number of small-effect genes and an incalculable amount of environmental factors. Merging Mendelian, quantitative and molecular approaches in the 1990s made it possible to map specific rodent behaviors to known chromosome regions. From that point on, Quantitative Trait Locus (QTL) analyses coupled with behavioral and molecular techniques, which involved in vivo isolation of relevant blocks of genes, opened new avenues for gene mapping and characterization. This review examines the QTL strategy applied to the behavioral study of emotionality, with a focus on the laboratory rat. We discuss the challenges, advances and limitations of the search for Quantitative Trait Genes (QTG) playing a role in regulating emotionality. For the past 25 years, we have marched the long journey from emotionality-related behaviors to genes. In this context, our experiences are used to illustrate why and how one should move forward in the molecular understanding of complex psychiatric illnesses. The promise of exploring genetic links between immunological and emotional responses are also discussed. New strategies based on humans, rodents and other animals (such as zebrafish) are also acknowledged, as they are likely to allow substantial progress to be made in the near future.
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Affiliation(s)
- André Ramos
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Natalli Granzotto
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Rafael Kremer
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Developmental and Cellular Biology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Ariela Maína Boeder
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Julia Fernandez Puñal de Araújo
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Developmental and Cellular Biology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Aline Guimarães Pereira
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Developmental and Cellular Biology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Geison Souza Izídio
- Behavior Genetics Laboratory, Department of Cell Biology, Embryology and Genetics, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Pharmacology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
- Graduate Program of Developmental and Cellular Biology, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
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Postnikova TY, Trofimova AM, Zakharova MV, Nosova OI, Brazhe AR, Korzhevskii DE, Semyanov AV, Zaitsev AV. Delayed Impairment of Hippocampal Synaptic Plasticity after Pentylenetetrazole-Induced Seizures in Young Rats. Int J Mol Sci 2022; 23:ijms232113461. [PMID: 36362260 PMCID: PMC9657086 DOI: 10.3390/ijms232113461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/26/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Data on the long-term consequences of a single episode of generalized seizures in infants are inconsistent. In this study, we examined the effects of pentylenetetrazole-induced generalized seizures in three-week-old rats. One month after the seizures, we detected a moderate neuronal loss in several hippocampal regions: CA1, CA3, and hilus, but not in the dentate gyrus. In addition, long-term synaptic potentiation (LTP) was impaired. We also found that the mechanism of plasticity induction was altered: additional activation of metabotropic glutamate receptors (mGluR1) is required for LTP induction in experimental rats. This disturbance of the plasticity induction mechanism is likely due to the greater involvement of perisynaptic NMDA receptors compared to receptors located in the core part of the postsynaptic density. This hypothesis is supported by experiments with selective blockades of core-located NMDA receptors by the use-dependent blocker MK-801. MK-801 had no effect on LTP induction in experimental rats and suppressed LTP in control animals. The weakening of the function of core-located NMDA receptors may be due to the disturbed clearance of glutamate from the synaptic cleft since the distribution of the astrocytic glutamate transporter EAAT2 in experimental animals was found to be altered.
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Affiliation(s)
- Tatyana Y. Postnikova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
| | - Alina M. Trofimova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
| | - Maria V. Zakharova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
| | - Olga I. Nosova
- Institute of Experimental Medicine, Saint Petersburg 197022, Russia
| | - Alexey R. Brazhe
- Faculty of Biology, Moscow State University, Moscow 119234, Russia
| | | | - Alexey V. Semyanov
- Faculty of Biology, Moscow State University, Moscow 119234, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
- Department of Clinical Pharmacology, Sechenov First Moscow State Medical University, Moscow 119435, Russia
| | - Aleksey V. Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
- Correspondence:
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Keith RE, Ogoe RH, Dumas TC. Behind the scenes: Are latent memories supported by calcium independent plasticity? Hippocampus 2022; 32:73-88. [PMID: 33905147 PMCID: PMC8548406 DOI: 10.1002/hipo.23332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 04/08/2021] [Accepted: 04/11/2021] [Indexed: 02/03/2023]
Abstract
N-methyl-D-aspartate receptors (NMDARs) can be considered to be the de facto "plasticity" receptors in the brain due to their central role in the activity-dependent modification of neuronal morphology and synaptic transmission. Since the 1980s, research on NMDARs has focused on the second messenger properties of calcium and the downstream signaling pathways that mediate alterations in neural form and function. Recently, NMDARs were shown to drive activity-dependent synaptic plasticity without calcium influx. How this "nonionotropic" plasticity occurs in vitro is becoming clearer, but research on its involvement in behavior and cognition is in its infancy. There is a partial overlap in the downstream signaling molecules that are involved in ionotropic and nonionotropic NMDAR-dependent plasticity. Given this, and prior studies of the cognitive impacts of ionotropic NMDAR plasticity, a preliminary model explaining how NMDAR nonionotropic plasticity affects learning and memory can be established. We hypothesize that nonionotropic NMDAR plasticity takes part in latent memory encoding in immature rodents through nonassociative depression of synaptic efficacy, and possibly shrinking of dendritic spines. Further, the late postnatal alteration in NMDAR composition in the hippocampus appears to reduce nonionotropic signaling and remove a restriction on memory retrieval. This framework substantially alters the canonical model of NMDAR involvement in spatial cognition and hippocampal maturation and provides novel and exciting inroads for future studies.
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Affiliation(s)
- Rachel E. Keith
- Interdisciplinary Program in Neuroscience, College of Science, George Mason University, Fairfax, Virginia
| | - Richard H. Ogoe
- Department of Psychology, College of Humanities and Social Sciences, George Mason University, Fairfax, Virginia
| | - Theodore C. Dumas
- Interdisciplinary Program in Neuroscience, College of Science, George Mason University, Fairfax, Virginia,Department of Psychology, College of Humanities and Social Sciences, George Mason University, Fairfax, Virginia
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8
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Grigoryan GA. Molecular-Cellular Mechanisms of Plastic Restructuring Produced by an Enriched Environment. Effects on Learning and Memory. NEUROCHEM J+ 2021. [DOI: 10.1134/s1819712421030041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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9
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Hsieh CP, Chang WT, Chen L, Chen HH, Chan MH. Differential inhibitory effects of resveratrol on excitotoxicity and synaptic plasticity: involvement of NMDA receptor subtypes. Nutr Neurosci 2021; 24:443-458. [PMID: 31331257 DOI: 10.1080/1028415x.2019.1641995] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Objectives: The neuroprotective effects of resveratrol against excitatory neurotoxicity have been associated with N-methyl-D-aspartate receptor (NMDAR) inhibition. This study examined the differential inhibitory effects of resveratrol on NMDAR-mediated responses in neuronal cells with different NMDAR subtype composition.Methods: The effects of resveratrol on NMDA-induced cell death and calcium influx in immature and mature rat primary cortical neurons were determined and compared. Moreover, the potencies and efficacies of resveratrol to inhibit NR1/NR2A, NR1/NR2B, NR1/NR2C, and NR1/NR2D NMDAR expressed in HEK 293 cells were evaluated.Results: Resveratrol significantly attenuated NMDA-induced cell death in mature neurons, but not in immature neurons. Resveratrol also concentration-dependently reduced NMDA-induced calcium influx among all NMDAR subtypes, but displayed NR2 subunit selectivity, with a potency rank order of NR2B = NR2D > NR2A = NR2C and an efficacy rank order of NR2B = NR2C > NR2A = NR2D. Data show the stronger inhibitory effects of resveratrol on NR1/NR2B than other subtypes. Moreover, resveratrol did not affect hippocampal long-term potentiation (LTP), but impaired long-term depression (LTD).Discussion: These findings reveal the specific NMDAR modulating profile of resveratrol, providing further insight into potential mechanisms underlying the protective effects of resveratrol on neurological disorders.
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Affiliation(s)
- Chung-Pin Hsieh
- Center for Neuropsychiatric Research, National Health Research Institutes, Zhunan, Taiwan
| | - Wei-Tang Chang
- Center for Neuropsychiatric Research, National Health Research Institutes, Zhunan, Taiwan
| | - Linyi Chen
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, Taiwan
| | - Hwei-Hsien Chen
- Center for Neuropsychiatric Research, National Health Research Institutes, Zhunan, Taiwan
- Institute of Neuroscience, National Chengchi University, Taipei, Taiwan
| | - Ming-Huan Chan
- Institute of Neuroscience, National Chengchi University, Taipei, Taiwan
- Research Center for Mind, Brain and Learning, National Chengchi University, Taipei, Taiwan
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10
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Avchalumov Y, Mandyam CD. Plasticity in the Hippocampus, Neurogenesis and Drugs of Abuse. Brain Sci 2021; 11:404. [PMID: 33810204 PMCID: PMC8004884 DOI: 10.3390/brainsci11030404] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/05/2021] [Accepted: 03/11/2021] [Indexed: 02/07/2023] Open
Abstract
Synaptic plasticity in the hippocampus assists with consolidation and storage of long-lasting memories. Decades of research has provided substantial information on the cellular and molecular mechanisms underlying synaptic plasticity in the hippocampus, and this review discusses these mechanisms in brief. Addiction is a chronic relapsing disorder with loss of control over drug taking and drug seeking that is caused by long-lasting memories of drug experience. Relapse to drug use is caused by exposure to context and cues associated with the drug experience, and is a major clinical problem that contributes to the persistence of addiction. This review also briefly discusses some evidence that drugs of abuse alter plasticity in the hippocampus, and that development of novel treatment strategies that reverse or prevent drug-induced synaptic alterations in the hippocampus may reduce relapse behaviors associated with addiction.
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Affiliation(s)
| | - Chitra D. Mandyam
- VA San Diego Healthcare System, San Diego, CA 92161, USA;
- Department of Anesthesiology, University of California San Diego, San Diego, CA 92161, USA
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11
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Bertocchi I, Eltokhi A, Rozov A, Chi VN, Jensen V, Bus T, Pawlak V, Serafino M, Sonntag H, Yang B, Burnashev N, Li SB, Obenhaus HA, Both M, Niewoehner B, Single FN, Briese M, Boerner T, Gass P, Rawlins JNP, Köhr G, Bannerman DM, Sprengel R. Voltage-independent GluN2A-type NMDA receptor Ca 2+ signaling promotes audiogenic seizures, attentional and cognitive deficits in mice. Commun Biol 2021; 4:59. [PMID: 33420383 PMCID: PMC7794508 DOI: 10.1038/s42003-020-01538-4] [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: 05/08/2020] [Accepted: 11/20/2020] [Indexed: 12/21/2022] Open
Abstract
The NMDA receptor-mediated Ca2+ signaling during simultaneous pre- and postsynaptic activity is critically involved in synaptic plasticity and thus has a key role in the nervous system. In GRIN2-variant patients alterations of this coincidence detection provoked complex clinical phenotypes, ranging from reduced muscle strength to epileptic seizures and intellectual disability. By using our gene-targeted mouse line (Grin2aN615S), we show that voltage-independent glutamate-gated signaling of GluN2A-containing NMDA receptors is associated with NMDAR-dependent audiogenic seizures due to hyperexcitable midbrain circuits. In contrast, the NMDAR antagonist MK-801-induced c-Fos expression is reduced in the hippocampus. Likewise, the synchronization of theta- and gamma oscillatory activity is lowered during exploration, demonstrating reduced hippocampal activity. This is associated with exploratory hyperactivity and aberrantly increased and dysregulated levels of attention that can interfere with associative learning, in particular when relevant cues and reward outcomes are disconnected in space and time. Together, our findings provide (i) experimental evidence that the inherent voltage-dependent Ca2+ signaling of NMDA receptors is essential for maintaining appropriate responses to sensory stimuli and (ii) a mechanistic explanation for the neurological manifestations seen in the NMDAR-related human disorders with GRIN2 variant-meidiated intellectual disability and focal epilepsy.
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Affiliation(s)
- Ilaria Bertocchi
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- Research Group of the Max Planck Institute for Medical Research at the Institute for Anatomy and Cell Biology of the Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
- Department of Neuroscience Rita Levi Montalcini, University of Turin, Via Cherasco 15, 10126, Torino, Italy
- Neuroscience Institute-Cavalieri-Ottolenghi Foundation (NICO), Laboratory of Neuropsychopharmacology, Regionale Gonzole 10, 10043 Orbassano, Torino, Italy
| | - Ahmed Eltokhi
- Research Group of the Max Planck Institute for Medical Research at the Institute for Anatomy and Cell Biology of the Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, Eberhard Karls University Tübingen, Otfried-Müller Str. 27, 72076, Tübingen, Germany
| | - Andrey Rozov
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- Department of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
- OpenLab of Neurobiology, Kazan Federal University, 8 Kremlyovskaya Street, Kazan, 420008, Russian Federation
- Federal Center of Brain Research and Neurotechnologies, Ostrovityanova Str 1/10, Moscow, 117997, Russia
| | - Vivan Nguyễn Chi
- Department of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Vidar Jensen
- Department of Molecular Medicine, Division of Physiology, Institute of Basic Medical Sciences, University of Oslo, Sognsvannsveien 9, 0372, Oslo, Norway
| | - Thorsten Bus
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- Research Group of the Max Planck Institute for Medical Research at the Institute for Anatomy and Cell Biology of the Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
| | - Verena Pawlak
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- Department of Behavior and Brain Organization, Research Center Caesar, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - Marta Serafino
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- FARMA-DERMA s.r.l. Via dell'Artigiano 6-8, 40010, Sala Bolognese, Italy
| | - Hannah Sonntag
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- Research Group of the Max Planck Institute for Medical Research at the Institute for Anatomy and Cell Biology of the Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
| | - Boyi Yang
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 JieFang Road, Wuhan, Hubei, 430030, China
| | - Nail Burnashev
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- INSERM UMR 1249 Mediterranean Institute of Neurobiology (INMED), Aix-Marseille University, Parc Scientifique de Luminy, 163 avenue de Luminy BP13, 13273, Marseille Cedex 09, France
| | - Shi-Bin Li
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, 1201 Welch Road, Stanford, CA, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford Way, Rm E152, Stanford, CA, 94305, USA
| | - Horst A Obenhaus
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- Research Group of the Max Planck Institute for Medical Research at the Institute for Anatomy and Cell Biology of the Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany
- Kavli Institute for Systems Neuroscience, Faculty of Medicine and Health Sciences, NTNU, Postboks 8905, NO-7491, Trondheim, Norway
| | - Martin Both
- Department of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Burkhard Niewoehner
- Department of Experimental Psychology, University of Oxford, Radcliffe Observatory, Anna Watts Building, Woodstock Rd, Oxford, OX2 6GG, UK
| | - Frank N Single
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- Miltenyi Biotec B.V. & Co. KG, Bergisch Gladbach, Friedrich-Ebert-Str. 68, 51429, Bergisch Gladbach, Germany
| | - Michael Briese
- Department of Experimental Psychology, University of Oxford, Radcliffe Observatory, Anna Watts Building, Woodstock Rd, Oxford, OX2 6GG, UK
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Versbacherstraße 5, 97080, Wuerzburg, Germany
| | - Thomas Boerner
- Department of Experimental Psychology, University of Oxford, Radcliffe Observatory, Anna Watts Building, Woodstock Rd, Oxford, OX2 6GG, UK
| | - Peter Gass
- RG Animal Models in Psychiatry, Animal Models Psychatry, Central Institute of Mental Health (CIMH), Faculty Mannheim, Heidelberg University, J5, 68159, Mannheim, Germany
| | - John Nick P Rawlins
- Department of Experimental Psychology, University of Oxford, Radcliffe Observatory, Anna Watts Building, Woodstock Rd, Oxford, OX2 6GG, UK
| | - Georg Köhr
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany
- Department of Neurophysiology, Medical Faculty Mannheim, Heidelberg University, Ludolf-Krehl-Str. 13-17, 68167, Mannheim, Germany
| | - David M Bannerman
- Department of Experimental Psychology, University of Oxford, Radcliffe Observatory, Anna Watts Building, Woodstock Rd, Oxford, OX2 6GG, UK.
| | - Rolf Sprengel
- Departments Molecular Neurobiology and Physiology at the Max Planck Institute for Medical Research, Jahnstr. 29, 69120, Heidelberg, Germany.
- Research Group of the Max Planck Institute for Medical Research at the Institute for Anatomy and Cell Biology of the Heidelberg University, Im Neuenheimer Feld 307, 69120, Heidelberg, Germany.
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12
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Abstract
Alcohol is one of the oldest pharmacological agents used for its sedative/hypnotic effects, and alcohol abuse and alcohol use disorder (AUD) continues to be major public health issue. AUD is strongly indicated to be a brain disorder, and the molecular and cellular mechanism/s by which alcohol produces its effects in the brain are only now beginning to be understood. In the brain, synaptic plasticity or strengthening or weakening of synapses, can be enhanced or reduced by a variety of stimulation paradigms. Synaptic plasticity is thought to be responsible for important processes involved in the cellular mechanisms of learning and memory. Long-term potentiation (LTP) is a form of synaptic plasticity, and occurs via N-methyl-D-aspartate type glutamate receptor (NMDAR or GluN) dependent and independent mechanisms. In particular, NMDARs are a major target of alcohol, and are implicated in different types of learning and memory. Therefore, understanding the effect of alcohol on synaptic plasticity and transmission mediated by glutamatergic signaling is becoming important, and this will help us understand the significant contribution of the glutamatergic system in AUD. In the first part of this review, we will briefly discuss the mechanisms underlying long term synaptic plasticity in the dorsal striatum, neocortex and the hippocampus. In the second part we will discuss how alcohol (ethanol, EtOH) can modulate long term synaptic plasticity in these three brain regions, mainly from neurophysiological and electrophysiological studies. Taken together, understanding the mechanism(s) underlying alcohol induced changes in brain function may lead to the development of more effective therapeutic agents to reduce AUDs.
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Affiliation(s)
| | - Chitra D Mandyam
- VA San Diego Healthcare System, San Diego, CA, USA.,Department of Anesthesiology, University of California San Diego, San Diego, CA, USA
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13
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Feldmann M, Beckmann D, Eysel UT, Manahan-Vaughan D. Early Loss of Vision Results in Extensive Reorganization of Plasticity-Related Receptors and Alterations in Hippocampal Function That Extend Through Adulthood. Cereb Cortex 2020; 29:892-905. [PMID: 30535137 PMCID: PMC6319173 DOI: 10.1093/cercor/bhy297] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/07/2018] [Indexed: 11/15/2022] Open
Abstract
Although by adulthood cortical structures and their capacity for processing sensory information have become established and stabilized, under conditions of cortical injury, or sensory deprivation, rapid reorganization occurs. Little is known as to the impact of this kind of adaptation on cellular processes related to memory encoding. However, imaging studies in humans suggest that following loss or impairment of a sensory modality, not only cortical but also subcortical structures begin to reorganize. It is likely that these processes are supported by neurotransmitter receptors that enable synaptic and cortical plasticity. Here, we explored to what extent the expression of plasticity-related proteins (GABA-A, GABA-B, GluN1, GluN2A, GluN2B) is altered following early vision loss, and whether this impacts on hippocampal function. We observed that in the period of 2-4 months postnatally in CBA/J-mice that experience hereditary postnatal retinal degeneration, systematic changes of GABA-receptor and NMDA-receptor subunit expression occurred that emerged first in the hippocampus and developed later in the cortex, compared to control mice that had normal vision. Changes were accompanied by significant impairments in hippocampal long-term potentiation and hippocampus-dependent learning. These data indicate that during cortical adaptation to early loss of vision, hippocampal information processing is compromised, and this status impacts on the acquisition of spatial representations.
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Affiliation(s)
- Mirko Feldmann
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Daniela Beckmann
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Ulf T Eysel
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
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14
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Beckmann D, Feldmann M, Shchyglo O, Manahan-Vaughan D. Hippocampal Synaptic Plasticity, Spatial Memory, and Neurotransmitter Receptor Expression Are Profoundly Altered by Gradual Loss of Hearing Ability. Cereb Cortex 2020; 30:4581-4596. [PMID: 32202614 PMCID: PMC7325716 DOI: 10.1093/cercor/bhaa061] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/20/2020] [Accepted: 02/12/2020] [Indexed: 12/27/2022] Open
Abstract
Sensory information comprises the substrate from which memories are created. Memories of spatial sensory experience are encoded by means of synaptic plasticity in the hippocampus. Hippocampal dependency on sensory information is highlighted by the fact that sudden and complete loss of a sensory modality results in an impairment of hippocampal function that persists for months. Effects are accompanied by extensive changes in the expression of neurotransmitter receptors in cortex and hippocampus, consistent with a substantial adaptive reorganization of cortical function. Whether gradual sensory loss affects hippocampal function is unclear. Progressive age-dependent hearing loss (presbycusis) is a risk factor for cognitive decline. Here, we scrutinized C57BL/6 mice that experience hereditary and cumulative deafness starting in young adulthood. We observed that 2–4 months postnatally, increases in the cortical and hippocampal expression of GluN2A and GluN2B subunits of the N-methyl-D-aspartate receptor occurred compared to control mice that lack sensory deficits. Furthermore, GABA and metabotropic glutamate receptor expression were significantly altered. Hippocampal synaptic plasticity was profoundly impaired and mice exhibited significant deficits in spatial memory. These data show that during cortical adaptation to cumulative loss of hearing, plasticity-related neurotransmitter expression is extensively altered in the cortex and hippocampus. Furthermore, cumulative sensory loss compromises hippocampal function.
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Affiliation(s)
- Daniela Beckmann
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum 44780, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum 44780, Germany
| | - Mirko Feldmann
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum 44780, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum 44780, Germany
| | - Olena Shchyglo
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum 44780, Germany
| | - Denise Manahan-Vaughan
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum 44780, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum 44780, Germany
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15
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Synaptic GluN2A-Containing NMDA Receptors: From Physiology to Pathological Synaptic Plasticity. Int J Mol Sci 2020; 21:ijms21041538. [PMID: 32102377 PMCID: PMC7073220 DOI: 10.3390/ijms21041538] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 02/20/2020] [Accepted: 02/21/2020] [Indexed: 12/16/2022] Open
Abstract
N-Methyl-d-Aspartate Receptors (NMDARs) are ionotropic glutamate-gated receptors. NMDARs are tetramers composed by several homologous subunits of GluN1-, GluN2-, or GluN3-type, leading to the existence in the central nervous system of a high variety of receptor subtypes with different pharmacological and signaling properties. NMDAR subunit composition is strictly regulated during development and by activity-dependent synaptic plasticity. Given the differences between GluN2 regulatory subunits of NMDAR in several functions, here we will focus on the synaptic pool of NMDARs containing the GluN2A subunit, addressing its role in both physiology and pathological synaptic plasticity as well as the contribution in these events of different types of GluN2A-interacting proteins.
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16
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Warming H, Pegasiou CM, Pitera AP, Kariis H, Houghton SD, Kurbatskaya K, Ahmed A, Grundy P, Vajramani G, Bulters D, Altafaj X, Deinhardt K, Vargas-Caballero M. A primate-specific short GluN2A-NMDA receptor isoform is expressed in the human brain. Mol Brain 2019; 12:64. [PMID: 31272478 PMCID: PMC6610962 DOI: 10.1186/s13041-019-0485-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 06/21/2019] [Indexed: 12/16/2022] Open
Abstract
Glutamate receptors of the N-methyl-D-aspartate (NMDA) family are coincident detectors of pre- and postsynaptic activity, allowing Ca2+ influx into neurons. These properties are central to neurological disease mechanisms and are proposed to be the basis of associative learning and memory. In addition to the well-characterised canonical GluN2A NMDAR isoform, large-scale open reading frames in human tissues had suggested the expression of a primate-specific short GluN2A isoform referred to as GluN2A-S. Here, we confirm the expression of both GluN2A transcripts in human and primate but not rodent brain tissue, and show that they are translated to two corresponding GluN2A proteins present in human brain. Furthermore, we demonstrate that recombinant GluN2A-S co-assembles with the obligatory NMDAR subunit GluN1 to form functional NMDA receptors. These findings suggest a more complex NMDAR repertoire in human brain than previously thought.
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Affiliation(s)
- Hannah Warming
- School of Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - Chrysia-Maria Pegasiou
- School of Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - Aleksandra P Pitera
- School of Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - Hanna Kariis
- School of Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - Steven D Houghton
- School of Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - Ksenia Kurbatskaya
- School of Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - Aminul Ahmed
- Wessex Neurological Centre, University Hospital Southampton, University of Southampton, Southampton, SO16 6YD, UK
| | - Paul Grundy
- Wessex Neurological Centre, University Hospital Southampton, University of Southampton, Southampton, SO16 6YD, UK
| | - Girish Vajramani
- School of Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, UK.,Wessex Neurological Centre, University Hospital Southampton, University of Southampton, Southampton, SO16 6YD, UK
| | - Diederik Bulters
- School of Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, UK.,Wessex Neurological Centre, University Hospital Southampton, University of Southampton, Southampton, SO16 6YD, UK
| | - Xavier Altafaj
- Neuropharmacology Unit, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Katrin Deinhardt
- School of Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - Mariana Vargas-Caballero
- School of Biological Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, UK.
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17
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Sullivan JA, Zhang XL, Sullivan AP, Vose LR, Moghadam AA, Fried VA, Stanton PK. Zinc enhances hippocampal long-term potentiation at CA1 synapses through NR2B containing NMDA receptors. PLoS One 2018; 13:e0205907. [PMID: 30485271 PMCID: PMC6261414 DOI: 10.1371/journal.pone.0205907] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 10/03/2018] [Indexed: 01/16/2023] Open
Abstract
The role of zinc (Zn2+), a modulator of N-methyl-D-aspartate (NMDA) receptors, in regulating long-term synaptic plasticity at hippocampal CA1 synapses is poorly understood. The effects of exogenous application of Zn2+ and of chelation of endogenous Zn2+ were examined on long-term potentiation (LTP) of stimulus-evoked synaptic transmission at Schaffer collateral (SCH) synapses in field CA1 of mouse hippocampal slices using whole-cell patch clamp and field recordings. Low micromolar concentrations of exogenous Zn2+ enhanced the induction of LTP, and this effect required activation of NMDA receptors containing NR2B subunits. Zn2+ elicited a selective increase in NMDA/NR2B fEPSPs, and removal of endogenous Zn2+ with high-affinity Zn2+ chelators robustly reduced the magnitude of stimulus-evoked LTP. Taken together, our data show that Zn2+ at physiological concentrations enhances activation of NMDA receptors containing NR2B subunits, and that this effect enhances the magnitude of LTP.
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Affiliation(s)
- John A. Sullivan
- Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States of America
- * E-mail:
| | - Xiao-lei Zhang
- Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States of America
| | - Arthur P. Sullivan
- Psychology & Education, Touro School of Health Sciences, New York, New York, United States of America
| | - Linnea R. Vose
- Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States of America
| | - Alexander A. Moghadam
- Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States of America
| | - Victor A. Fried
- Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States of America
| | - Patric K. Stanton
- Cell Biology & Anatomy, New York Medical College, Valhalla, New York, United States of America
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18
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Lundbye CJ, Toft AKH, Banke TG. Inhibition of GluN2A NMDA receptors ameliorates synaptic plasticity deficits in the Fmr1 -/y mouse model. J Physiol 2018; 596:5017-5031. [PMID: 30132892 DOI: 10.1113/jp276304] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 08/20/2018] [Indexed: 02/06/2023] Open
Abstract
KEY POINTS Fragile X syndrome (FXS) is a genetic condition that is the most common form of inherited intellectual impairment and causes a range of neurodevelopmental complications including learning disabilities and intellectual disability and shares many characteristics with autism spectrum disorder (ASD). In the FXS mouse model, Fmr1-/y , impaired synaptic plasticity was restored by pharmacologically inhibiting GluN2A-containing NMDA receptors but not GluN2B-containing receptors. Similar results were obtained by crossing Fmr1-/y with GluN2A knock-out (Grin2A-/- ) mice. These results suggest that dampening the elevated levels of GluN2A-containing NMDA receptors in Fmr1-/y mice has the potential to restore hyperexcitability of the neural circuitry to (a more) normal-like level of brain activity. ABSTRACT NMDA receptors (NMDARs) play important roles in synaptic plasticity at central excitatory synapses, and dysregulation of their function may lead to severe disorders such Fragile X syndrome (FXS). FXS is caused by transcriptional silencing of the FMR1 gene followed by lack of the encoding protein. Here we examined the effects of pharmacological and genetic manipulation of hippocampal NMDAR functions in long-term potentiation (LTP) and depression (LTD). We found impaired NMDAR-dependent LTP in the Fmr1-deficient mice, which could be fully restored when GluN2A-containing NMDARs was pharmacological inhibited. Interestingly, similar LTP effects were observed when the GluN2A gene (Grin2a) was deleted in Fmr1-/y mice (Fmr1-/y /Grin2a-/- double knockout). In addition, GluN2A inhibition improved elevated mGluR5-dependent LTD to normal level in the Fmr1-/y mouse. These findings suggest that GluN2A is a promising target in FXS research that could help us better understand the disorder.
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Affiliation(s)
- Camilla J Lundbye
- Institute of Biomedicine - Physiology, Aarhus University, DK-8000, Aarhus, Denmark
| | - Anna Karina H Toft
- Institute of Biomedicine - Physiology, Aarhus University, DK-8000, Aarhus, Denmark
| | - Tue G Banke
- Institute of Biomedicine - Physiology, Aarhus University, DK-8000, Aarhus, Denmark
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19
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Sanders EM, Nyarko-Odoom AO, Zhao K, Nguyen M, Liao HH, Keith M, Pyon J, Kozma A, Sanyal M, McHail DG, Dumas TC. Separate functional properties of NMDARs regulate distinct aspects of spatial cognition. ACTA ACUST UNITED AC 2018; 25:264-272. [PMID: 29764972 PMCID: PMC5959228 DOI: 10.1101/lm.047290.118] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/12/2018] [Indexed: 11/25/2022]
Abstract
N-methyl-d-aspartate receptors (NMDARs) at excitatory synapses are central to activity-dependent synaptic plasticity and learning and memory. NMDARs act as ionotropic and metabotropic receptors by elevating postsynaptic calcium concentrations and by direct intracellular protein signaling. In the forebrain, these properties are controlled largely by the auxiliary GluN2 subunits, GluN2A and GluN2B. While calcium conductance through NMDAR channels and intracellular protein signaling make separate contributions to synaptic plasticity, it is not known if these properties individually influence learning and memory. To address this issue, we created chimeric GluN2 subunits containing the amino-terminal domain and transmembrane domains from GluN2A or GluN2B fused to the carboxy-terminal domain of GluN2B (termed ABc) or GluN2A ATD (termed BAc), respectively, and expressed these mutated GluN2 subunits in transgenic mice. Expression was confirmed at the mRNA level and protein subunit translation and translocation into dendrites were observed in forebrain neurons. In the spatial version of the Morris water maze, BAc mice displayed signs of a learning deficit. In contrast, ABc animals performed similarly to wild-types during training, but showed a more direct approach to the goal location during a long-term memory test. There was no effect of ABc or BAc expression in a nonspatial water escape task. Since background expression is predominantly GluN2A in mature animals, the results suggest that spatial learning is more sensitive to manipulations of the amino-terminal domain and transmembrane domains (calcium conductance) and long-term memory is regulated more by the carboxy-terminal domain (intracellular protein signaling).
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Affiliation(s)
- Erin M Sanders
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia 22030, USA
| | - Akua O Nyarko-Odoom
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia 22030, USA
| | - Kevin Zhao
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia 22030, USA
| | - Michael Nguyen
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia 22030, USA
| | - Hong Hong Liao
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia 22030, USA
| | - Matthew Keith
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia 22030, USA
| | - Jane Pyon
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia 22030, USA
| | - Alyssa Kozma
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia 22030, USA
| | - Mohima Sanyal
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia 22030, USA
| | - Daniel G McHail
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia 22030, USA
| | - Theodore C Dumas
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia 22030, USA.,Psychology Department, George Mason University, Fairfax, Virginia 22030, USA
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20
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Han JY, Kim JK, Kim JH, Oh BS, Cho WJ, Jung YD, Lee SG. Neurorestorative effects of epigallocatechin-3-Gallate on cognitive function in a chronic cerebral hypoperfusion rat model. Restor Neurol Neurosci 2018; 34:367-77. [PMID: 27080069 DOI: 10.3233/rnn-150586] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE This study investigated whether (-)-epigallocatechin-3-gallate (EGCG) can enhance cognition by a neurorestorative effect in a rat model of bilateral common carotid artery occlusion (BCCAO). METHODS Forty-eight male, 8-week-old Sprague-Dawley rats were randomly allocated to four groups 6 weeks after BCCAO or sham operation: EGCG-single intravenous injection (25 mg/kg/day; SIV group), EGCG-multiple intraperitoneal injection (50 mg/kg/day for 5 days; MIP group), untreated BCCAO group (untreated group), and sham-operated group (sham group). RESULTS Escape latency was significantly shorter in the SIV and MIP groups than in the untreated group. SIV and MIP groups were significantly different from the untreated group in the activity of superoxide dismutase and the content of malondialdehyde (p < 0.05). Protein expression level of brain-derived neurotrophic factor was not significantly different between groups (p > 0.05), while protein expression of vascular endothelial growth factor was significantly lower in the SIV group than in the untreated group (p < 0.05). Protein expression of N-methyl-D-aspartate receptor subunits NR1 and NR2B was significantly higher in the MIP group than in the untreated group (p < 0.05). CONCLUSIONS EGCG administration at 6 weeks after BCCAO is neurorestorative via an anti-oxidant effect and synaptogenesis, except for angiogenesis.
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Affiliation(s)
- Jae-Young Han
- Department of Physical & Rehabilitation Medicine, Chonnam National University Medical School & Hospital, Gwangju City, Republic of Korea
| | - Jung-Kook Kim
- Department of Rehabilitation Standard & Policy, National Rehabilitation Center Research Institute, Seoul City, Republic of Korea
| | - Jae-Hong Kim
- Department of Acupuncture & Moxibustion Medicine, College of Korean Medicine, Dong-Shin University, Naju City, Republic of Korea
| | - Bong-Seok Oh
- Department of Sports and Leisure Science, Sunchon National University, Sunchon City, Republic of Korea
| | - Wan-Ju Cho
- Department of Physical Education, Chosun University, Gwangju City, Republic of Korea
| | - Young Do Jung
- Department of Biochemistry, Chonnam National University Medical School, Gwangju City, Republic of Korea
| | - Sam-Gyu Lee
- Department of Physical & Rehabilitation Medicine, Chonnam National University Medical School & Hospital, Gwangju City, Republic of Korea
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21
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Qu Z, Wang Y, Li X, Wu L, Wang Y. TRPC6 expression in neurons is differentially regulated by NR2A- and NR2B-containing NMDA receptors. J Neurochem 2017; 143:282-293. [PMID: 28902407 DOI: 10.1111/jnc.14215] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 08/30/2017] [Accepted: 09/07/2017] [Indexed: 02/04/2023]
Abstract
The expression of transient receptor potential canonical 6 (TRPC6) in central nervous system (CNS) is important for neuronal functions and certain neural disorders. However, the regulatory mechanism of TRPC6 expression in neurons is still obscure. In this study, we show that TRPC6 expression in the primary cultured cortical neurons is bidirectionally regulated by glutamate. Activation of NR2A-containing NMDARs induces TRPC6 transcription through a calcineurin-dependent pathway. In contrast, activation of NR2B-containing NMDARs causes TRPC6 degradation through calpain. Thus, TRPC6 expression in neurons is regulated by glutamate in a bidirectional manner that is dependent on NR2A and NR2B.
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Affiliation(s)
- Zhongwei Qu
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China.,The Graduate School, University of Chinese Academy of Sciences, Beijing, China
| | - Yuqing Wang
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China.,The Graduate School, University of Chinese Academy of Sciences, Beijing, China
| | - Xia Li
- Center of Cognition and Brain Science, Beijing Institute of Medical Sciences, Beijing, China
| | - Lin Wu
- Center of Cognition and Brain Science, Beijing Institute of Medical Sciences, Beijing, China
| | - Yizheng Wang
- Laboratory of Neural Signal Transduction, Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China.,Center of Cognition and Brain Science, Beijing Institute of Medical Sciences, Beijing, China
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22
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Bröker-Lai J, Kollewe A, Schindeldecker B, Pohle J, Nguyen Chi V, Mathar I, Guzman R, Schwarz Y, Lai A, Weißgerber P, Schwegler H, Dietrich A, Both M, Sprengel R, Draguhn A, Köhr G, Fakler B, Flockerzi V, Bruns D, Freichel M. Heteromeric channels formed by TRPC1, TRPC4 and TRPC5 define hippocampal synaptic transmission and working memory. EMBO J 2017; 36:2770-2789. [PMID: 28790178 DOI: 10.15252/embj.201696369] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 07/01/2017] [Accepted: 07/07/2017] [Indexed: 12/30/2022] Open
Abstract
Canonical transient receptor potential (TRPC) channels influence various neuronal functions. Using quantitative high-resolution mass spectrometry, we demonstrate that TRPC1, TRPC4, and TRPC5 assemble into heteromultimers with each other, but not with other TRP family members in the mouse brain and hippocampus. In hippocampal neurons from Trpc1/Trpc4/Trpc5-triple-knockout (Trpc1/4/5-/-) mice, lacking any TRPC1-, TRPC4-, or TRPC5-containing channels, action potential-triggered excitatory postsynaptic currents (EPSCs) were significantly reduced, whereas frequency, amplitude, and kinetics of quantal miniature EPSC signaling remained unchanged. Likewise, evoked postsynaptic responses in hippocampal slice recordings and transient potentiation after tetanic stimulation were decreased. In vivo, Trpc1/4/5-/- mice displayed impaired cross-frequency coupling in hippocampal networks and deficits in spatial working memory, while spatial reference memory was unaltered. Trpc1/4/5-/- animals also exhibited deficiencies in adapting to a new challenge in a relearning task. Our results indicate the contribution of heteromultimeric channels from TRPC1, TRPC4, and TRPC5 subunits to the regulation of mechanisms underlying spatial working memory and flexible relearning by facilitating proper synaptic transmission in hippocampal neurons.
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Affiliation(s)
- Jenny Bröker-Lai
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Astrid Kollewe
- Institute of Physiology, University of Freiburg, Freiburg, Germany
| | - Barbara Schindeldecker
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Jörg Pohle
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany.,Physiology of Neural Networks, Psychiatry/Psychopharmacology, Central Institute of Mental Health, J5, Heidelberg University, Mannheim, Germany
| | - Vivan Nguyen Chi
- Institute of Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Ilka Mathar
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Raul Guzman
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Yvonne Schwarz
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Alan Lai
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Petra Weißgerber
- Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | | | - Alexander Dietrich
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University München, München, Germany
| | - Martin Both
- Institute of Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Rolf Sprengel
- Max Planck Research Group of the Max Planck Institute for Medical Research at the Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Georg Köhr
- Physiology of Neural Networks, Psychiatry/Psychopharmacology, Central Institute of Mental Health, J5, Heidelberg University, Mannheim, Germany
| | - Bernd Fakler
- Institute of Physiology, University of Freiburg, Freiburg, Germany.,BIOSS, Center for Biological Signaling Studies, University of Freiburg, Freiburg, Germany‡
| | - Veit Flockerzi
- Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Dieter Bruns
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
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23
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Ballesteros JJ, Buschler A, Köhr G, Manahan-Vaughan D. Afferent Input Selects NMDA Receptor Subtype to Determine the Persistency of Hippocampal LTP in Freely Behaving Mice. Front Synaptic Neurosci 2016; 8:33. [PMID: 27818632 PMCID: PMC5073893 DOI: 10.3389/fnsyn.2016.00033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/26/2016] [Indexed: 01/07/2023] Open
Abstract
The glutamatergic N-methyl-D-aspartate receptor (NMDAR) is critically involved in many forms of hippocampus-dependent memory that may be enabled by synaptic plasticity. Behavioral studies with NMDAR antagonists and NMDAR subunit (GluN2) mutants revealed distinct contributions from GluN2A- and GluN2B-containing NMDARs to rapidly and slowly acquired memory performance. Furthermore, studies of synaptic plasticity, in genetically modified mice in vitro, suggest that GluN2A and GluN2B may contribute in different ways to the induction and longevity of synaptic plasticity. In contrast to the hippocampal slice preparation, in behaving mice, the afferent frequencies that induce synaptic plasticity are very restricted and specific. In fact, it is the stimulus pattern and not variations in afferent frequency that determine the longevity of long-term potentiation (LTP) in vivo. Here, we explored the contribution of GluN2A and GluN2B to LTP of differing magnitudes and persistence in freely behaving mice. We applied differing high-frequency stimulation (HFS) patterns at 100 Hz to the hippocampal CA1 region, to induce NMDAR-dependent LTP in wild-type (WT) mice, that endured for <1 h (early (E)-LTP), (LTP, 2–4 h) or >24 h (late (L)-LTP). In GluN2A-knockout (KO) mice, E-LTP (HFS, 50 pulses) was significantly reduced in magnitude and duration, whereas LTP (HFS, 2 × 50 pulses) and L-LTP (HFS, 4 × 50 pulses) were unaffected compared to responses in WT animals. By contrast, pharmacological antagonism of GluN2B in WT had no effect on E-LTP but significantly prevented LTP. E-LTP and LTP were significantly impaired by GluN2B antagonism in GluN2A-KO mice. These data indicate that the pattern of afferent stimulation is decisive for the recruitment of distinct GluN2A and GluN2B signaling pathways that in turn determine the persistency of hippocampal LTP. Whereas brief bursts of patterned stimulation preferentially recruit GluN2A and lead to weak and short-lived forms of LTP, prolonged, more intense, afferent activation recruits GluN2B and leads to robust and persistent LTP. These unique signal-response properties of GluN2A and GluN2B enable qualitative differentiation of information encoding in hippocampal synapses.
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Affiliation(s)
- Jesús J Ballesteros
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum Bochum, Germany
| | - Arne Buschler
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum Bochum, Germany
| | - Georg Köhr
- Max Planck Institute for Medical Research Heidelberg, Germany
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24
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France G, Fernández-Fernández D, Burnell ES, Irvine MW, Monaghan DT, Jane DE, Bortolotto ZA, Collingridge GL, Volianskis A. Multiple roles of GluN2B-containing NMDA receptors in synaptic plasticity in juvenile hippocampus. Neuropharmacology 2016; 112:76-83. [PMID: 27523302 PMCID: PMC5084684 DOI: 10.1016/j.neuropharm.2016.08.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/09/2016] [Accepted: 08/10/2016] [Indexed: 11/28/2022]
Abstract
In the CA1 area of the hippocampus N-methyl-d-aspartate receptors (NMDARs) mediate the induction of long-term depression (LTD), short-term potentiation (STP) and long-term potentiation (LTP). All of these forms of synaptic plasticity can be readily studied in juvenile hippocampal slices but the involvement of particular NMDAR subunits in the induction of these different forms of synaptic plasticity is currently unclear. Here, using NVP-AAM077, Ro 25-6981 and UBP145 to target GluN2A-, 2B- and 2D-containing NMDARs respectively, we show that GluN2B-containing NMDARs (GluN2B) are involved in the induction of LTD, STP and LTP in slices prepared from P14 rat hippocampus. A concentration of Ro (1 μM) that selectively blocks GluN2B-containing diheteromers is able to block LTD. It also inhibits a component of STP without affecting LTP. A higher concentration of Ro (10 μM), that also inhibits GluN2A/B triheteromers, blocks LTP. UBP145 selectively inhibits the Ro-sensitive component of STP whereas NVP inhibits LTP. These data are consistent with a role of GluN2B diheretomers in LTD, a role of both GluN2B- and GluN2D- containing NMDARs in STP and a role of GluN2A/B triheteromers in LTP. This article is part of the Special Issue entitled ‘Ionotropic glutamate receptors’. Inhibition of GluN2Bs in P14 is sufficient for blockade of NMDAR-LTD. GluN2A and GluN2D subunits are not required for the induction of LTD. Induction of STP involves GluN2B and GluN2D subunits. Induction of LTP depends on GluN2A/2B triheteromers.
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Affiliation(s)
- Grace France
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Diego Fernández-Fernández
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Erica S Burnell
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Mark W Irvine
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Daniel T Monaghan
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, USA
| | - David E Jane
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Zuner A Bortolotto
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Graham L Collingridge
- Centre for Synaptic Plasticity, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK; Dept Physiology, University of Toronto and Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Canada
| | - Arturas Volianskis
- Centre for Synaptic Plasticity, School of Clinical Sciences, University of Bristol, Bristol, UK; Centre for Neuroscience and Trauma, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, UK.
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25
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Berlin S, Szobota S, Reiner A, Carroll EC, Kienzler MA, Guyon A, Xiao T, Trauner D, Isacoff EY. A family of photoswitchable NMDA receptors. eLife 2016; 5. [PMID: 26929991 PMCID: PMC4786437 DOI: 10.7554/elife.12040] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/31/2016] [Indexed: 02/07/2023] Open
Abstract
NMDA receptors, which regulate synaptic strength and are implicated in learning and memory, consist of several subtypes with distinct subunit compositions and functional properties. To enable spatiotemporally defined, rapid and reproducible manipulation of function of specific subtypes, we engineered a set of photoswitchable GluN subunits ('LiGluNs'). Photo-agonism of GluN2A or GluN2B elicits an excitatory drive to hippocampal neurons that can be shaped in time to mimic synaptic activation. Photo-agonism of GluN2A at single dendritic spines evokes spine-specific calcium elevation and expansion, the morphological correlate of LTP. Photo-antagonism of GluN2A alone, or in combination with photo-antagonism of GluN1a, reversibly blocks excitatory synaptic currents, prevents the induction of long-term potentiation and prevents spine expansion. In addition, photo-antagonism in vivo disrupts synaptic pruning of developing retino-tectal projections in larval zebrafish. By providing precise and rapidly reversible optical control of NMDA receptor subtypes, LiGluNs should help unravel the contribution of specific NMDA receptors to synaptic transmission, integration and plasticity.
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Affiliation(s)
- Shai Berlin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Stephanie Szobota
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Andreas Reiner
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Elizabeth C Carroll
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Michael A Kienzler
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Alice Guyon
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia Antipolis, Nice, France
| | - Tong Xiao
- Department of Chemistry, University of California, Berkeley, Berkeley, United States
| | - Dirk Trauner
- Department of Chemistry, Center of Integrated Protein Science, University of Munich, Munich, Germany
| | - Ehud Y Isacoff
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States.,Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States.,Physical Bioscience Division, Lawrence Berkeley National Laboratory, Berkeley, United States
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26
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Effects of diazoxide on Aβ1-42-induced expression of the NR2B subunit in cultured cholinergic neurons. Mol Med Rep 2015; 12:8301-5. [PMID: 26496862 DOI: 10.3892/mmr.2015.4457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 09/10/2015] [Indexed: 11/05/2022] Open
Abstract
The accumulation of amyloid-β protein (Aβ) is significant in the pathogenesis of Alzheimer's disease. Several previous studies indicate that the NR2B‑containing N‑methyl‑D‑aspartate receptors are critically involved in the Aβ mediated disruption of neuronal function. Diazoxide (DZ), a highly selective drug capable of opening mitochondrial ATP‑sensitive potassium channels, has neuroprotective effects against neuronal cell death. However, the mechanism by which DZ protects cholinergic neurons against Aβ‑induced cytotoxicity remains to be elucidated. The present study was designed to investigate the effects of DZ pretreatment against Aβ1‑42‑induced expression of NR2B in order to gain novel insights into the neuroprotective mechanisms. Following exposure to Aβ1‑42 for 24 h, the expression of the NR2B subunit remained unchanged compared with the control group. However, a significant increase in the expression of the NR2B subunit was observed following treatment with Aβ1‑42 for 72 h (P<0.05); and the upregulation of the expression of the NR2B subunit was reversed by pretreatment with DZ (P<0.05). These results suggested that DZ may counteract Aβ1‑42‑mediated cytotoxicity by alleviating the expression of NR2B.
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27
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Stein LR, Zorumski CF, Imai SI, Izumi Y. Nampt is required for long-term depression and the function of GluN2B subunit-containing NMDA receptors. Brain Res Bull 2015; 119:41-51. [PMID: 26481044 DOI: 10.1016/j.brainresbull.2015.10.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 09/13/2015] [Accepted: 10/12/2015] [Indexed: 01/01/2023]
Abstract
Nicotinamide adenine dinucleotide (NAD(+)) is an essential coenzyme/cosubstrate for many biological processes in cellular metabolism. The rate-limiting step in the major pathway of mammalian NAD(+) biosynthesis is mediated by nicotinamide phosphoribosyltransferase (Nampt). Previously, we showed that mice lacking Nampt in forebrain excitatory neurons (CamKIIαNampt(-/-) mice) exhibited hyperactivity, impaired learning and memory, and reduced anxiety-like behaviors. However, it remained unclear if these functional effects were accompanied by synaptic changes. Here, we show that CamKIIαNampt(-/-) mice have impaired induction of long-term depression (LTD) in the Schaffer collateral pathway, but normal induction of long-term potentiation (LTP), at postnatal day 30. Pharmacological assessments demonstrated that CamKIIαNampt(-/-) mice also display dysfunction of synaptic GluN2B (NR2B)-containing N-methyl-d-aspartate receptors (NMDARs) prior to changes in NMDAR subunit expression. These results support a novel, important role for Nampt-mediated NAD(+) biosynthesis in LTD and in the function of GluN2B-containing NMDARs.
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Affiliation(s)
- Liana Roberts Stein
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Department of Psychiatry, The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, Campus Box 8134, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
| | - Charles F Zorumski
- Department of Psychiatry, The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, Campus Box 8134, 660 South Euclid Avenue, St. Louis, MO 63110, USA; Department of Anatomy and Neurobiology, Washington University School of Medicine, Campus Box 8134, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
| | - Shin-Ichiro Imai
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
| | - Yukitoshi Izumi
- Department of Psychiatry, The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, Campus Box 8134, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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28
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Espinosa F, Xuan Z, Liu S, Powell CM. Neuroligin 1 modulates striatal glutamatergic neurotransmission in a pathway and NMDAR subunit-specific manner. Front Synaptic Neurosci 2015; 7:11. [PMID: 26283958 PMCID: PMC4518159 DOI: 10.3389/fnsyn.2015.00011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/18/2015] [Indexed: 12/18/2022] Open
Abstract
Together with its presynaptic partner Neurexin 1 (Nxn1), Neuroligin 1 (NL1) participates in synapse specification and synapse maintenance. We and others have shown that NL1 can also modulate glutamatergic synaptic function in the central nervous system of rodent models. These molecular/cellular changes can translate into altered animal behaviors that are thought to be analogous to symptomatology of neuropsychiatric disorders. For example, in dorsal striatum of NL1 deletion mice, we previously reported that the ratio N-methyl-D-aspartate receptor (NMDAR) mediated synaptic currents to α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor (AMPAR) mediated synaptic currents (NMDA/AMPA) is reduced in medium spiny neuron (MSNs). Importantly, this reduction in NMDA/AMPA ratio correlated with increased repetitive grooming. The striatum is the input nucleus of the basal ganglia (BG). Classical models of this circuitry imply that there are two principal pathways that render distinct and somewhat opposite striatal outputs critical to the function of these nuclei in modulating motor behavior. Thus, we set out to better characterize the effects of NL1 deletion on direct and indirect pathways of the dorsal striatum by genetically labeling MSNs participating in the direct and indirect pathways. We demonstrate that a decrease in NMDAR-mediated currents is limited to MSNs of the direct pathway. Furthermore, the decrease in NMDAR-mediated currents is largely due to a reduction in function of NMDARs containing the GluN2A subunit. In contrast, indirect pathway MSNs in NL1 knockout (KO) mice showed a reduction in the frequency of miniature excitatory neurotransmission not observed in the direct pathway. Thus, NL1 deletion differentially affects direct and indirect pathway MSNs in dorsal striatum. These findings have potential implications for striatal function in NL1 KO mice.
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Affiliation(s)
- Felipe Espinosa
- Department of Neurology and Neurotherapeutics, The University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Zhong Xuan
- Department of Neurology and Neurotherapeutics, The University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Shunan Liu
- Department of Neurology and Neurotherapeutics, The University of Texas Southwestern Medical Center Dallas, TX, USA
| | - Craig M Powell
- Department of Neurology and Neurotherapeutics, The University of Texas Southwestern Medical Center Dallas, TX, USA ; Neuroscience Graduate Program, The University of Texas Southwestern Medical Center Dallas, TX, USA ; Department of Psychiatry, The University of Texas Southwestern Medical Center Dallas, TX, USA
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29
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Keller MK, Draguhn A, Both M, Reichinnek S. Activity-dependent plasticity of mouse hippocampal assemblies in vitro. Front Neural Circuits 2015; 9:21. [PMID: 26041998 PMCID: PMC4435105 DOI: 10.3389/fncir.2015.00021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 04/27/2015] [Indexed: 11/13/2022] Open
Abstract
Memory formation is associated with the generation of transiently stable neuronal assemblies. In hippocampal networks, such groups of functionally coupled neurons express highly ordered spatiotemporal activity patterns which are coordinated by local network oscillations. One of these patterns, sharp wave-ripple complexes (SPW-R), repetitively activates previously established groups of memory-encoding neurons, thereby supporting memory consolidation. This function implies that repetition of specific SPW-R induces plastic changes which render the underlying neuronal assemblies more stable. We modeled this repetitive activation in an in vitro model of SPW-R in mouse hippocampal slices. Weak electrical stimulation upstream of the CA3-CA1 networks reliably induced SPW-R of stereotypic waveform, thus representing re-activation of similar neuronal activity patterns. Frequent repetition of these patterns (100 times) reduced the variance of both, evoked and spontaneous SPW-R waveforms, indicating stabilization of pre-existing assemblies. These effects were most pronounced in the CA1 subfield and depended on the timing of stimulation relative to spontaneous SPW-R. Additionally, plasticity of SPW-R was blocked by application of a NMDA receptor antagonist, suggesting a role for associative synaptic plasticity in this process. Thus, repetitive activation of specific patterns of SPW-R causes stabilization of memory-related networks.
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Affiliation(s)
- Martin K Keller
- Institute of Physiology and Pathophysiology, University of Heidelberg Heidelberg, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, University of Heidelberg Heidelberg, Germany
| | - Martin Both
- Institute of Physiology and Pathophysiology, University of Heidelberg Heidelberg, Germany
| | - Susanne Reichinnek
- Institute of Physiology and Pathophysiology, University of Heidelberg Heidelberg, Germany ; Mediterranean Institute of Neurobiology (INMED), INSERM Marseille, France
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30
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Effect of acute NR2B antagonist treatment on long-term potentiation in the rat hippocampus. Brain Res 2015; 1609:31-9. [PMID: 25796435 DOI: 10.1016/j.brainres.2015.03.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 03/05/2015] [Accepted: 03/10/2015] [Indexed: 12/11/2022]
Abstract
The long lasting antidepressant response seen following acute, i.v. ketamine administration in patients with treatment-resistant depression (TRD) is thought to result from enhanced synaptic plasticity in cortical and hippocampal circuits. Using extracellular field recordings in rat hippocampal slices, we show that a single dose of the non-selective NMDA receptor antagonist ketamine or CP-101,606, a selective antagonist of the NR2B subunit of the NMDA receptor, enhances hippocampal synaptic plasticity induced with high frequency stimulation (HFS) 24h after dosing - a time at which plasma concentrations of the drug are no longer detectable in the animal. These results indicate that acute inhibition of NMDA receptors containing the NR2B subunit can lead to long-lasting changes in hippocampal plasticity.
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31
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McHail DG, Dumas TC. Multiple forms of metaplasticity at a single hippocampal synapse during late postnatal development. Dev Cogn Neurosci 2015; 12:145-54. [PMID: 25752732 PMCID: PMC4887277 DOI: 10.1016/j.dcn.2015.01.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 12/22/2014] [Accepted: 01/22/2015] [Indexed: 11/01/2022] Open
Abstract
Metaplasticity refers to adjustment in the requirements for induction of synaptic plasticity based on the prior history of activity. Numerous forms of developmental metaplasticity are observed at Schaffer collateral synapses in the rat hippocampus at the end of the third postnatal week. Emergence of spatial learning and memory at this developmental stage suggests possible involvement of metaplasticity in the final maturation of the hippocampus. Three distinct metaplastic phenomena are apparent. (1) As transmitter release probability increases with increasing age, presynaptic potentiation is reduced. (2) Alterations in the composition and channel conductance properties of AMPARs facilitate the induction of postsynaptic potentiation with increasing age. (3) Low frequency stimulation inhibits subsequent induction of potentiation in animals older but not younger than 3 weeks of age. Thus, many forms of plasticity expressed at SC-CA1 synapses are different in rats younger and older than 3 weeks of age, illustrating the complex orchestration of physiological modifications that underlie the maturation of hippocampal excitatory synaptic transmission. This review paper describes three late postnatal modifications to synaptic plasticity induction in the hippocampus and attempts to relate these metaplastic changes to developmental alterations in hippocampal network activity and the maturation of contextual learning.
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Affiliation(s)
- Daniel G McHail
- Molecular Neuroscience Department, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, United States
| | - Theodore C Dumas
- Molecular Neuroscience Department, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, United States.
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32
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Jacobs S, Cui Z, Feng R, Wang H, Wang D, Tsien JZ. Molecular and genetic determinants of the NMDA receptor for superior learning and memory functions. PLoS One 2014; 9:e111865. [PMID: 25360708 PMCID: PMC4216132 DOI: 10.1371/journal.pone.0111865] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/06/2014] [Indexed: 12/17/2022] Open
Abstract
The opening-duration of the NMDA receptors implements Hebb's synaptic coincidence-detection and is long thought to be the rate-limiting factor underlying superior memory. Here, we investigate the molecular and genetic determinants of the NMDA receptors by testing the “synaptic coincidence-detection time-duration” hypothesis vs. “GluN2B intracellular signaling domain” hypothesis. Accordingly, we generated a series of GluN2A, GluN2B, and GluN2D chimeric subunit transgenic mice in which C-terminal intracellular domains were systematically swapped and overexpressed in the forebrain excitatory neurons. The data presented in the present study supports the second hypothesis, the “GluN2B intracellular signaling domain” hypothesis. Surprisingly, we found that the voltage-gated channel opening-durations through either GluN2A or GluN2B are sufficient and their temporal differences are marginal. In contrast, the C-terminal intracellular domain of the GluN2B subunit is necessary and sufficient for superior performances in long-term novel object recognition and cued fear memories and superior flexibility in fear extinction. Intriguingly, memory enhancement correlates with enhanced long-term potentiation in the 10–100 Hz range while requiring intact long-term depression capacity at the 1–5 Hz range.
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Affiliation(s)
- Stephanie Jacobs
- Brain and Behavior Discovery Institute and Department of Neurology, Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Zhenzhong Cui
- Brain and Behavior Discovery Institute and Department of Neurology, Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Ruiben Feng
- Brain and Behavior Discovery Institute and Department of Neurology, Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
| | - Huimin Wang
- Shanghai Institute of Functional Genomics, East China Normal University, Shanghai, China
| | - Deheng Wang
- Banna Biomedical Research Institute, Xi-Shuang-Ban-Na Prefecture, Yunnan Province, China
| | - Joe Z. Tsien
- Brain and Behavior Discovery Institute and Department of Neurology, Medical College of Georgia at Georgia Regents University, Augusta, Georgia, United States of America
- * E-mail:
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33
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Marquardt K, Saha M, Mishina M, Young JW, Brigman JL. Loss of GluN2A-containing NMDA receptors impairs extra-dimensional set-shifting. GENES BRAIN AND BEHAVIOR 2014; 13:611-7. [PMID: 25059550 DOI: 10.1111/gbb.12156] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 07/08/2014] [Accepted: 07/21/2014] [Indexed: 11/28/2022]
Abstract
Glutamate neurotransmission via the N-methyl-D-aspartate receptor (NMDAR) is thought to mediate the synaptic plasticity underlying learning and memory formation. There is increasing evidence that deficits in NMDAR function are involved in the pathophysiology of cognitive dysfunction seen in neuropsychiatric disorders and addiction. NMDAR subunits confer different physiological properties to the receptor, interact with distinct intracellular postsynaptic scaffolding and signaling molecules, and are differentially expressed during development. Despite these known differences, the relative contribution of individual subunit composition to synaptic plasticity and learning is not fully elucidated. We have previously shown that constitutive deletion of GluN2A subunit in the mouse impairs discrimination and re-learning phase of reversal when exemplars are complex picture stimuli, but spares acquisition and extinction of non-discriminative visually cued instrumental response. To investigate the role of GluN2A containing NMDARs in executive control, we tested GluN2A knockout (GluN2A(KO) ), heterozygous (GluN2A(HET) ) and wild-type (WT) littermates on an attentional set-shifting task using species-specific stimulus dimensions. To further explore the nature of deficits in this model, mice were tested on a visual discrimination reversal paradigm using simplified rotational stimuli. GluN2A(KO) were not impaired on discrimination or reversal problems when tactile or olfactory stimuli were used, or when visual stimuli were sufficiently easy to discriminate. GluN2A(KO) showed a specific and significant impairment in ventromedial prefrontal cortex-mediated set-shifting. Together these results support a role for GluN2A containing NMDAR in modulating executive control that can be masked by overlapping deficits in attentional processes during high task demands.
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Affiliation(s)
- K Marquardt
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, USA
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34
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Fan X, Jin WY, Wang YT. The NMDA receptor complex: a multifunctional machine at the glutamatergic synapse. Front Cell Neurosci 2014; 8:160. [PMID: 24959120 PMCID: PMC4051310 DOI: 10.3389/fncel.2014.00160] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 05/26/2014] [Indexed: 01/11/2023] Open
Abstract
The N-methyl-D-aspartate receptors (NMDARs) are part of a large multiprotein complex at the glutamatergic synapse. The assembly of NMDARs with synaptic proteins offers a means to regulate NMDAR channel properties and receptor trafficking, and couples NMDAR activation to distinct intracellular signaling pathways, thus contributing to the versatility of NMDAR functions. Receptor-protein interactions at the synapse provide a dynamic and powerful mechanism for regulating synaptic efficacy, but can also contribute to NMDAR overactivation-induced excitotoxicity and cellular damage under pathological conditions. An emerging concept is that by understanding the mechanisms and functions of disease-specific protein-protein interactions in the NMDAR complex, we may be able to develop novel therapies based on protein-NMDAR interactions for the treatment of brain diseases in which NMDAR dysfunction is at the root of their pathogenesis.
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Affiliation(s)
- Xuelai Fan
- Brain Research Centre and Department of Medicine, Vancouver Coastal Health Research Institute, University of British Columbia Vancouver, BC, Canada
| | - Wu Yang Jin
- Brain Research Centre and Department of Medicine, Vancouver Coastal Health Research Institute, University of British Columbia Vancouver, BC, Canada
| | - Yu Tian Wang
- Brain Research Centre and Department of Medicine, Vancouver Coastal Health Research Institute, University of British Columbia Vancouver, BC, Canada
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35
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Walkup WG, Kennedy MB. PDZ affinity chromatography: a general method for affinity purification of proteins based on PDZ domains and their ligands. Protein Expr Purif 2014; 98:46-62. [PMID: 24607360 DOI: 10.1016/j.pep.2014.02.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 02/24/2014] [Accepted: 02/26/2014] [Indexed: 12/16/2022]
Abstract
PDZ (PSD-95, DiscsLarge, ZO1) domains function in nature as protein binding domains within scaffold and membrane-associated proteins. They comprise ∼90 residues and make specific, high affinity interactions with complementary C-terminal peptide sequences, with other PDZ domains, and with phospholipids. We hypothesized that the specific, strong interactions of PDZ domains with their ligands would make them well suited for use in affinity chromatography. Here we describe a novel affinity chromatography method applicable for the purification of proteins that contain PDZ domain-binding ligands, either naturally or introduced by genetic engineering. We created a series of affinity resins comprised of PDZ domains from the scaffold protein PSD-95, or from neuronal nitric oxide synthase (nNOS), coupled to solid supports. We used them to purify heterologously expressed neuronal proteins or protein domains containing endogenous PDZ domain ligands, eluting the proteins with free PDZ domain peptide ligands. We show that Proteins of Interest (POIs) lacking endogenous PDZ domain ligands can be engineered as fusion products containing C-terminal PDZ domain ligand peptides or internal, N- or C-terminal PDZ domains and then can be purified by the same method. Using this method, we recovered recombinant GFP fused to a PDZ domain ligand in active form as verified by fluorescence yield. Similarly, chloramphenicol acetyltransferase (CAT) and β-Galactosidase (LacZ) fused to a C-terminal PDZ domain ligand or an N-terminal PDZ domain were purified in active form as assessed by enzymatic assay. In general, PDZ domains and ligands derived from PSD-95 were superior to those from nNOS for this method. PDZ Domain Affinity Chromatography promises to be a versatile and effective method for purification of a wide variety of natural and recombinant proteins.
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Affiliation(s)
- Ward G Walkup
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Blvd, Mail Code 216-76, Pasadena, CA 91125, USA.
| | - Mary B Kennedy
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Blvd, Mail Code 216-76, Pasadena, CA 91125, USA
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36
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Shipton OA, Paulsen O. GluN2A and GluN2B subunit-containing NMDA receptors in hippocampal plasticity. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130163. [PMID: 24298164 PMCID: PMC3843894 DOI: 10.1098/rstb.2013.0163] [Citation(s) in RCA: 192] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
N-Methyl-d-aspartate receptor (NMDAR)-dependent synaptic plasticity is a strong candidate to mediate learning and memory processes that require the hippocampus. This plasticity is bidirectional, and how the same receptor can mediate opposite changes in synaptic weights remains a conundrum. It has been suggested that the NMDAR subunit composition could be involved. Specifically, one subunit composition of NMDARs would be responsible for the induction of long-term potentiation (LTP), whereas NMDARs with a different subunit composition would be engaged in the induction of long-term depression (LTD). Unfortunately, the results from studies that have investigated this hypothesis are contradictory, particularly in relation to LTD. Nevertheless, current evidence does suggest that the GluN2B subunit might be particularly important for plasticity and may make a synapse bidirectionally malleable. In particular, we conclude that the presence of GluN2B subunit-containing NMDARs at the postsynaptic density might be a necessary, though not a sufficient, condition for the strengthening of individual synapses. This is owing to the interaction of GluN2B with calcium/calmodulin-dependent protein kinase II (CaMKII) and is distinct from its contribution as an ion channel.
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Affiliation(s)
- Olivia A. Shipton
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3QX, UK
| | - Ole Paulsen
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
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37
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Ionotropic glutamate receptors and voltage-gated Ca²⁺ channels in long-term potentiation of spinal dorsal horn synapses and pain hypersensitivity. Neural Plast 2013; 2013:654257. [PMID: 24224102 PMCID: PMC3808892 DOI: 10.1155/2013/654257] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 08/27/2013] [Accepted: 08/27/2013] [Indexed: 12/18/2022] Open
Abstract
Over the last twenty years of research on cellular mechanisms of pain hypersensitivity, long-term potentiation (LTP) of synaptic transmission in the spinal cord dorsal horn (DH) has emerged as an important contributor to pain pathology. Mechanisms that underlie LTP of spinal DH neurons include changes in the numbers, activity, and properties of ionotropic glutamate receptors (AMPA and NMDA receptors) and of voltage-gated Ca2+ channels. Here, we review the roles and mechanisms of these channels in the induction and expression of spinal DH LTP, and we present this within the framework of the anatomical organization and synaptic circuitry of the spinal DH. Moreover, we compare synaptic plasticity in the spinal DH with classical LTP described for hippocampal synapses.
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38
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Kessler JP. Control of cleft glutamate concentration and glutamate spill-out by perisynaptic glia: uptake and diffusion barriers. PLoS One 2013; 8:e70791. [PMID: 23951010 PMCID: PMC3741295 DOI: 10.1371/journal.pone.0070791] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 06/25/2013] [Indexed: 01/17/2023] Open
Abstract
Most glutamatergic synapses in the mammalian central nervous system are covered by thin astroglial processes that exert a dual action on synaptically released glutamate: they form physical barriers that oppose diffusion and they carry specific transporters that remove glutamate from the extracellular space. The present study was undertaken to investigate the dual action of glia by means of computer simulation. A realistic synapse model based on electron microscope data and Monte Carlo algorithms were used for this purpose. Results show (1) that physical obstacles formed by glial processes delay glutamate exit from the cleft and (2) that this effect is efficiently counteracted by glutamate uptake. Thus, depending on transporter densities, the presence of perisynaptic glia may result in increased or decreased glutamate transient in the synaptic cleft. Changes in temporal profiles of cleft glutamate concentration induced by glia differentially impact the response of the various synaptic and perisynaptic receptor subtypes. In particular, GluN2B- and GluN2C-NMDA receptor responses are strongly modified while GluN2A-NMDA receptor responses are almost unaffected. Thus, variations in glial transporter expression may allow differential tuning of NMDA receptors according to their subunit composition. In addition, simulation data suggest that the sink effect generated by transporters accumulation in the vicinity of the release site is the main mechanism limiting glutamate spill-out. Physical obstacles formed by glial processes play a comparatively minor role.
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39
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Chung C. NMDA receptor as a newly identified member of the metabotropic glutamate receptor family: clinical implications for neurodegenerative diseases. Mol Cells 2013; 36:99-104. [PMID: 23740429 PMCID: PMC3887951 DOI: 10.1007/s10059-013-0113-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/08/2013] [Accepted: 05/09/2013] [Indexed: 12/17/2022] Open
Abstract
Recent reports have proposed a novel function for the N-methyl-D-aspartate (NMDA) receptor (NMDAR), a well-known excitatory, ionotropic receptor. A series of observations employing pharmacological techniques has proposed that upon ligand binding, this ionotropic receptor can actually function via signaling cascades independent of traditional ionotropic action. Moreover, the "metabotropic" action of NMDARs is suggested to mediate a form of synaptic plasticity, namely long-term synaptic depression (LTD), which shares cellular mechanisms with the synaptic deficits observed in Alzheimer's disease. Given that a growing body of clinical and preclinical evidence strongly recommends NMDAR antagonists for their therapeutic potentials and advantages in a variety of diseases, further investigation into their molecular and cellular mechanisms is required to better understand the "metabotropic" action of NMDARs.
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Affiliation(s)
- ChiHye Chung
- Department of Biological Sciences, Konkuk University, Seoul 143-701, Korea.
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40
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GluN2A versus GluN2B: twins, but quite different. Neurosci Bull 2013; 29:761-72. [PMID: 23604599 DOI: 10.1007/s12264-013-1336-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 11/15/2012] [Indexed: 10/26/2022] Open
Abstract
N-Methyl-D-aspartate receptors (NMDARs) play vital roles in the central nervous system, as they are primary mediators of Ca(2+) influx during synaptic activity. The subunits that compose NMDARs share similar topological structures but are distinct in distribution and pharmacological properties, as well as physiological and pathological functions, which make the NMDAR one of the most complex and elusive ionotropic glutamate receptors. In this review, we focus on GluN2A and GluN2B, the primary NMDAR subunits in the cortex and hippocampus, and discuss their differences in developmental expression, brain distribution, trafficking, and functional properties during neuronal activity.
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41
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Sanders EM, Nguyen MA, Zhou KC, Hanks ME, Yusuf KA, Cox DN, Dumas TC. Developmental modification of synaptic NMDAR composition and maturation of glutamatergic synapses: matching postsynaptic slots with receptor pegs. THE BIOLOGICAL BULLETIN 2013; 224:1-13. [PMID: 23493503 DOI: 10.1086/bblv224n1p1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The numbers and types of ionotropic glutamate receptors at most vertebrate central excitatory synapses are altered as a function of changes in input activity patterns that occur during postnatal development. Activity-dependent developmental alterations in glutamate receptors underlie lasting changes in synaptic efficacy (plasticity) and metaplasticity (the plasticity of synaptic plasticity), which are critical elements of normal brain maturation. Understanding the specific involvement of glutamate receptors in synaptic development and function is made multiplicatively complex by the existence of a large number of glutamate receptor subunits, numerous subunit-specific amino acid sequences that regulate receptor function, and subunit-specific synaptic insertion restrictions imposed by associated anchoring proteins. Many receptor properties are altered when subunits are switched, so it is unclear which individual receptor property or properties underlie changes in synaptic function and plasticity during postnatal development. As a result, a more detailed understanding of the factors that regulate synaptic and cognitive development will involve mutations in glutamate receptor subunits that separate individual receptor properties and permit synaptic insertion at both immature and mature synapses in genetically modified organisms. This position paper focuses on structural modifications in N-methyl-d-aspartate receptors (NMDARs) that occur during postnatal forebrain development and attempts to provide a method for pursuing a more complete understanding of the functional ramifications of developmental alterations in NMDAR subunit composition.
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Affiliation(s)
- Erin M Sanders
- Molecular Neuroscience Department, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030, USA
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42
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Bartlett TE, Wang YT. The intersections of NMDAR-dependent synaptic plasticity and cell survival. Neuropharmacology 2013; 74:59-68. [PMID: 23357336 DOI: 10.1016/j.neuropharm.2013.01.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/09/2013] [Accepted: 01/14/2013] [Indexed: 10/27/2022]
Abstract
The discovery of a requirement for N-methyl d-aspartate receptor (NMDAR) activation in long-term potentiation (LTP) set off an explosion of interest in the mechanisms of NMDAR-dependent synaptic plasticity. Meanwhile other research has advanced our understanding of how NMDAR activation regulates neuronal death and survival. Surprisingly, there have been few attempts to correlate these important areas of research. Here we review current knowledge of the various mechanisms of NMDAR-dependent synaptic plasticity that are shared with neuronal survival and death, while drawing comparisons with the proneurotrophin/neurotrophin receptor and intracellular signaling systems. Our conclusion is that NMDAR-dependent LTP and long-term depression (LTD) share many common mechanisms with cell survival and cell death, respectively. The intersections of plasticity and cell survival may represent novel avenues for neuroprotection. This article is part of the Special Issue entitled 'Glutamate Receptor-Dependent Synaptic Plasticity'.
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Affiliation(s)
- Thomas E Bartlett
- Brain Research Centre, Room F270, University of British Columbia, 2211 Wesbrook Mall, Vancouver, BC V6T 2B5, Canada
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43
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Naylor DE, Liu H, Niquet J, Wasterlain CG. Rapid surface accumulation of NMDA receptors increases glutamatergic excitation during status epilepticus. Neurobiol Dis 2013; 54:225-38. [PMID: 23313318 DOI: 10.1016/j.nbd.2012.12.015] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 12/20/2012] [Accepted: 12/28/2012] [Indexed: 02/06/2023] Open
Abstract
After 1h of lithium-pilocarpine status epilepticus (SE), immunocytochemical labeling of NMDA receptor NR1 subunits reveals relocation of subunits from the interior to the cell surface of dentate gyrus granule cells and CA3 pyramidal cells. Simultaneously, an increase in NMDA-miniature excitatory postsynaptic currents (mEPSC) as well as an increase in NMDA receptor-mediated tonic currents is observed in hippocampal slices after SE. Mean-variance analysis of NMDA-mEPSCs estimates that the number of functional postsynaptic NMDA receptors per synapse increases 38% during SE, and antagonism by ifenprodil suggests that an increase in the surface representation of NR2B-containing NMDA receptors is responsible for the augmentation of both the phasic and tonic excitatory currents with SE. These results provide a potential mechanism for an enhancement of glutamatergic excitation that maintains SE and may contribute to excitotoxic injury during SE. Therapies that directly antagonize NMDA receptors may be a useful therapeutic strategy during refractory SE.
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Affiliation(s)
- David E Naylor
- Department of Neurology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, USA; Department of Neurology, Veterans Administration Greater Los Angeles Healthcare System, USA.
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44
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Ryan TJ, Kopanitsa MV, Indersmitten T, Nithianantharajah J, Afinowi NO, Pettit C, Stanford LE, Sprengel R, Saksida LM, Bussey TJ, O'Dell TJ, Grant SGN, Komiyama NH. Evolution of GluN2A/B cytoplasmic domains diversified vertebrate synaptic plasticity and behavior. Nat Neurosci 2013; 16:25-32. [PMID: 23201971 PMCID: PMC3979286 DOI: 10.1038/nn.3277] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 11/10/2012] [Indexed: 02/07/2023]
Abstract
Two genome duplications early in the vertebrate lineage expanded gene families, including GluN2 subunits of the NMDA receptor. Diversification between the four mammalian GluN2 proteins occurred primarily at their intracellular C-terminal domains (CTDs). To identify shared ancestral functions and diversified subunit-specific functions, we exchanged the exons encoding the GluN2A (also known as Grin2a) and GluN2B (also known as Grin2b) CTDs in two knock-in mice and analyzed the mice's biochemistry, synaptic physiology, and multiple learned and innate behaviors. The eight behaviors were genetically separated into four groups, including one group comprising three types of learning linked to conserved GluN2A/B regions. In contrast, the remaining five behaviors exhibited subunit-specific regulation. GluN2A/B CTD diversification conferred differential binding to cytoplasmic MAGUK proteins and differential forms of long-term potentiation. These data indicate that vertebrate behavior and synaptic signaling acquired increased complexity from the duplication and diversification of ancestral GluN2 genes.
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Affiliation(s)
- Tomás J Ryan
- Genes to Cognition Programme, Wellcome Trust Sanger Institute, Cambridge, UK
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45
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Liu DD, Yang Q, Li ST. Activation of extrasynaptic NMDA receptors induces LTD in rat hippocampal CA1 neurons. Brain Res Bull 2012; 93:10-6. [PMID: 23270879 DOI: 10.1016/j.brainresbull.2012.12.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Revised: 12/12/2012] [Accepted: 12/13/2012] [Indexed: 12/29/2022]
Abstract
In the adult rat hippocampus, activation of N-methyl-d-aspartate receptors (NMDARs) is required for the induction of certain forms of synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD). Several studies have indicated the opposing role of synaptic NMDARS (S-NMDARs) versus extrasynaptic NMDARs (ES-NMDARs) in CREB-dependent gene regulation and neuronal survival/death. The contribution of ES-NMDARs in synaptic plasticity, however, remains unclear. Here we investigated the contribution of ES-NMDARs on LTD induction in CA1 neurons of rat hippocampal slices. ES-NMDARs were selectively activated by theta burst stimulation (TBS) after selective blockade of S-NMDARs with pairing of 5 Hz stimulation and MK-801, an irreversible use-dependent antagonist of NMDARs. Application of TBS in naïve slices evoked a transient potentiation. In contrast, the activation of ES-NMDARs evoked a robust LTD. These results suggest the involvement of ES-NMDARs in LTD induction.
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Affiliation(s)
- Dan-dan Liu
- Bio-X Institute, Shanghai Jiao Tong University, 800 Dongchuan Road, 200240 Shanghai, PR China
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46
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Delaney AJ, Sedlak PL, Autuori E, Power JM, Sah P. Synaptic NMDA receptors in basolateral amygdala principal neurons are triheteromeric proteins: physiological role of GluN2B subunits. J Neurophysiol 2012; 109:1391-402. [PMID: 23221411 DOI: 10.1152/jn.00176.2012] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
N-methyl-(D)-aspartate (NMDA) receptors are heteromultimeric ion channels that contain an essential GluN1 subunit and two or more GluN2 (GluN2A-GluN2D) subunits. The biophysical properties and physiological roles of synaptic NMDA receptors are dependent on their subunit composition. In the basolateral amygdala (BLA), it has been suggested that the plasticity that underlies fear learning requires activation of heterodimeric receptors composed of GluN1/GluN2B subunits. In this study, we investigated the subunit composition of NMDA receptors present at synapses on principal neurons in the BLA. Purification of the synaptic fraction showed that both GluN2A and GluN2B subunits are present at synapses, and co-immunoprecipitation revealed the presence of receptors containing both GluN2A and GluN2B subunits. The kinetics of NMDA receptor-mediated synaptic currents and pharmacological blockade indicate that heterodimeric GluN1/GluN2B receptors are unlikely to be present at glutamatergic synapses on BLA principal neurons. Selective RNA interference-mediated knockdown of GluN2A subunits converted synaptic receptors to a GluN1/GluN2B phenotype, whereas knockdown of GluN2B subunits had no effect on the kinetics of the synaptically evoked NMDA current. Blockade of GluN1/GluN2B heterodimers with ifenprodil had no effect, but knockdown of GluN2B disrupted the induction of CaMKII-dependent long-term potentiation at these synapses. These results suggest that, on BLA principal neurons, GluN2B subunits are only present as GluN1/GluN2A/GluN2B heterotrimeric NMDA receptors. The GluN2B subunit has little impact on the kinetics of the receptor, but is essential for the recruitment of signaling molecules essential for synaptic plasticity.
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Affiliation(s)
- Andrew J Delaney
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
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47
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Maki BA, Aman TK, Amico-Ruvio SA, Kussius CL, Popescu GK. C-terminal domains of N-methyl-D-aspartic acid receptor modulate unitary channel conductance and gating. J Biol Chem 2012; 287:36071-80. [PMID: 22948148 PMCID: PMC3476275 DOI: 10.1074/jbc.m112.390013] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 08/11/2012] [Indexed: 11/06/2022] Open
Abstract
NMDA receptors (NRs) are glutamate-gated calcium-permeable channels that are essential for normal synaptic transmssion and contribute to neurodegeneration. Tetrameric proteins consist of two obligatory GluN1 (N1) and two GluN2 (N2) subunits, of which GluN2A (2A) and GluN2B (2B) are prevalent in adult brain. The intracellularly located C-terminal domains (CTDs) make a significant portion of mass of the receptors and are essential for plasticity and excitotoxicity, but their functions are incompletely defined. Recent evidence shows that truncation of the N2 CTD alters channel kinetics; however, the mechanism by which this occurs is unclear. Here we recorded activity from individual NRs lacking the CTDs of N1, 2A, or 2B and determined the gating mechanisms of these receptors. Receptors lacking the N1 CTDs had larger unitary conductance and faster deactivation kinetics, receptors lacking the 2A or 2B CTDs had longer openings and longer desensitized intervals, and the first 100 amino acids of the N2 CTD were essential for these changes. In addition, receptors lacking the CTDs of either 2A or 2B maintained isoform-specific kinetic differences and swapping CTDs between 2A and 2B had no effect on single-channel properties. Based on these results, we suggest that perturbations in the CTD can modify the NR-mediated signal in a subunit-dependent manner, in 2A these effects are most likely mediated by membrane-proximal residues, and the isoform-specific biophysical properties conferred by 2A and 2B are CTD-independent. The kinetic mechanisms we developed afford a quantitative approach to understanding how the intracellular domains of NR subunits can modulate the responses of the receptor.
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Affiliation(s)
| | - Teresa K. Aman
- the Department of Biochemistry, University at Buffalo, State University of New York, Buffalo, New York 14214
| | - Stacy A. Amico-Ruvio
- the Department of Biochemistry, University at Buffalo, State University of New York, Buffalo, New York 14214
| | - Cassandra L. Kussius
- the Department of Biochemistry, University at Buffalo, State University of New York, Buffalo, New York 14214
| | - Gabriela K. Popescu
- From the Neuroscience Program and
- the Department of Biochemistry, University at Buffalo, State University of New York, Buffalo, New York 14214
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48
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Buschler A, Goh JJ, Manahan-Vaughan D. Frequency dependency of NMDA receptor-dependent synaptic plasticity in the hippocampal CA1 region of freely behaving mice. Hippocampus 2012; 22:2238-48. [PMID: 22707377 DOI: 10.1002/hipo.22041] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/10/2012] [Indexed: 11/08/2022]
Abstract
Hippocampal synaptic plasticity in the form of long-term potentiation (LTP) and long-term depression (LTD) is likely to enable synaptic information storage in support of memory formation. The mouse brain has been subjected to intensive scrutiny in this regard; however, a multitude of studies has examined synaptic plasticity in the hippocampal slice preparation, whereas very few have addressed synaptic plasticity in the freely behaving mouse. Almost nothing is known about the frequency or N-methyl-D-aspartate receptor (NMDAR) dependency of hippocampal synaptic plasticity in the intact mouse brain. Therefore, in this study, we investigated the forms of synaptic plasticity that are elicited at different afferent stimulation frequencies. We also addressed the NMDAR dependency of this phenomenon. Adult male C57BL/6 mice were chronically implanted with a stimulating electrode into the Schaffer collaterals and a recording electrode into the Stratum radiatum of the CA1 region. To examine synaptic plasticity, we chose protocols that were previously shown to produce either LTP or LTD in the hippocampal slice preparation. Low-frequency stimulation (LFS) at 1 Hz (900 pulses) had no effect on evoked responses. LFS at 3 Hz (ranging from 200 up to 2 × 900 pulses) elicited short-term depression (STD, <45 min). LFS at 3 Hz (1,200 pulses) elicited slow-onset potentiation, high-frequency stimulation (HFS) at 100 Hz (100 or 200 pulses) or at 50 Hz was ineffective, whereas 100 Hz (50 pulses) elicited short-term potentiation (STP). HFS at 100 Hz given as 2 × 30, 2 × 50, or 4 × 50 pulses elicited LTP (>24 h). Theta-burst stimulation was ineffective. Antagonism of the NMDAR prevented STD, STP, and LTP. This study shows for the first time that protocols that effectively elicit persistent synaptic plasticity in the slice preparation elicit distinctly different effects in the intact mouse brain. Persistent LTD could not be elicited with any of the protocols tested. Plasticity responses are NMDAR dependent, suggesting that these phenomena are relevant for hippocampus-dependent learning.
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Affiliation(s)
- Arne Buschler
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
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49
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Dalton GL, Wu DC, Wang YT, Floresco SB, Phillips AG. NMDA GluN2A and GluN2B receptors play separate roles in the induction of LTP and LTD in the amygdala and in the acquisition and extinction of conditioned fear. Neuropharmacology 2012; 62:797-806. [DOI: 10.1016/j.neuropharm.2011.09.001] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 08/29/2011] [Accepted: 09/02/2011] [Indexed: 01/14/2023]
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50
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Punnakkal P, Jendritza P, Köhr G. Influence of the intracellular GluN2 C-terminal domain on NMDA receptor function. Neuropharmacology 2012; 62:1985-92. [PMID: 22245680 DOI: 10.1016/j.neuropharm.2011.12.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2010] [Revised: 12/02/2011] [Accepted: 12/20/2011] [Indexed: 10/14/2022]
Abstract
Excitatory neurotransmission mediated by N-methyl-d-aspartate receptors (NMDARs) is fundamental to learning and memory and, when impaired, causes certain neurological disorders. NMDARs are heterotetrameric complexes composed of two GluN1 [NR1] and two GluN2(A-D) [NR2(A-D)] subunits. The GluN2 subunit is responsible for subunit-specific channel activity and gating kinetics including activation (rise time), peak open probability (peak Po) and deactivation (decay time). The peak Po of recombinant NMDARs was recently described to be controlled by the extracellular GluN2 N-terminal domain (NTD). The cytoplasmic GluN2 C-terminal domain (CTD) could also be involved, because the Po of synaptic NMDARs is reduced in mice expressing C-terminally truncated GluN2 subunits. Here, we examined the role of the GluN2 cytoplasmic tail for NMDAR channel activity and gating in HEK-293 cells. C-terminal truncation of GluN2A, GluN2B or GluN2C did not change the subunit-specific rise time but accelerated the decay time of glutamate-activated currents. Furthermore, the peak Po was reduced by about 50% for GluN2A and GluN2B but not for GluN2C. These results indicated that the CTD of GluN2 has a modulating role in NMDAR gating even in the absence of interacting synaptic proteins. Reduction of peak Po and deactivation kinetics following GluN2 C-terminal truncation were reversed by re-introducing a CTD from a different GluN2 subunit. Thus, the CTDs of GluN2 subunits behave as constitutive structural elements required for normal functioning of NMDARs but are not involved in determining the subunit-specific gating properties of NMDARs.
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Affiliation(s)
- Pradeep Punnakkal
- Department of Molecular Neurobiology, Max-Planck-Institute for Medical Research, Jahnstrasse 29, D-69120 Heidelberg, Germany
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