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Gharami K, Biswas SC. Glutamate treatment mimics LTP- and LTD-like biochemical activity in viable synaptosome preparation. Neurochem Int 2020; 134:104655. [PMID: 31899196 DOI: 10.1016/j.neuint.2019.104655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 12/05/2019] [Accepted: 12/29/2019] [Indexed: 01/28/2023]
Abstract
Long-term potentiation (LTP) and long-term depression (LTD) are considered to be the cellular mechanisms behind the increase or decrease of synaptic strength respectively. Electrophysiologically induced LTP/LTD is associated with the activation of glutamate receptors in the synaptic terminals resulting in the initiation of biochemical processes in the postsynaptic terminals and thus propagation of synaptic activity. Isolated nerve endings i.e. synaptosome preparation was used to study here, the biochemical phenotypes of LTP and LTD, and glutamate treatment in varying concentration for different time was used to induce those biochemical phenomena. Treatment with 200 μM glutamate showed increased GluA1 phosphorylation at serine 831 and activation of CaMKIIα by phosphorylation at threonine 286 like LTP, whereas 100 μM glutamate treatment showed decrease in GluA1 phosphorylation level at both pGluA1(S831) and pGluA1(S845), and activation of GSK3β by de-phosphorylating pGSK3β at serine 9 like LTD. The 200 μM glutamate treatment was associated with an increase in the local translation of Arc, BDNF, CaMKIIα and Homer1, whereas 100 μM glutamate treatments resulted in decrease in the level of the said synaptic proteins and the effect was blocked by the proteasomal inhibitor, Lactasystin. Both, the local translation and local degradation was sensitive to the Ca2+ chellator, Bapta-AM, indicating that both the phenomena were dependent on the rise in intra-synaptosomal Ca2+, like LTP and LTD. Overall the results of the present study suggest that synaptosomal preparations can be a viable alternative to study mechanisms underlying the biochemical activities of LTP/LTD in short term.
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Affiliation(s)
- Kusumika Gharami
- Cell Biology & Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India.
| | - Subhas C Biswas
- Cell Biology & Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India.
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102
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Rodríguez-Arce E, Cancino P, Arias-Calderón M, Silva-Matus P, Saldías M. Oxoisoaporphines and Aporphines: Versatile Molecules with Anticancer Effects. Molecules 2019; 25:E108. [PMID: 31892146 PMCID: PMC6983244 DOI: 10.3390/molecules25010108] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 02/07/2023] Open
Abstract
Cancer is a disease that involves impaired genome stability with a high mortality index globally. Since its discovery, many have searched for effective treatment, assessing different molecules for their anticancer activity. One of the most studied sources for anticancer therapy is natural compounds and their derivates, like alkaloids, which are organic molecules containing nitrogen atoms in their structure. Among them, oxoisoaporphine and sampangine compounds are receiving increased attention due to their potential anticancer effects. Boldine has also been tested as an anticancer molecule. Boldine is the primary alkaloid extract from boldo, an endemic tree in Chile. These compounds and their derivatives have unique structural properties that potentially have an anticancer mechanism. Different studies showed that this molecule can target cancer cells through several mechanisms, including reactive oxygen species generation, DNA binding, and telomerase enzyme inhibition. In this review, we summarize the state-of-art research related to oxoisoaporphine, sampangine, and boldine, with emphasis on their structural characteristics and the relationship between structure, activity, methods of extraction or synthesis, and anticancer mechanism. With an effective cancer therapy still lacking, these three compounds are good candidates for new anticancer research.
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Affiliation(s)
- Esteban Rodríguez-Arce
- Instituto de Investigación e Innovación en Salud, Facultad de Ciencias de la Salud, Universidad Central de Chile, Santiago 8370178, Chile;
| | - Patricio Cancino
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago 8380544, Chile;
| | - Manuel Arias-Calderón
- Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370146, Chile;
| | - Paul Silva-Matus
- Departamento de Ciencias de la Salud, Universidad de Aysén, Coyhaique 5951537, Chile;
| | - Marianela Saldías
- Instituto de Investigación e Innovación en Salud, Facultad de Ciencias de la Salud, Universidad Central de Chile, Santiago 8370178, Chile;
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103
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Fossati M, Assendorp N, Gemin O, Colasse S, Dingli F, Arras G, Loew D, Charrier C. Trans-Synaptic Signaling through the Glutamate Receptor Delta-1 Mediates Inhibitory Synapse Formation in Cortical Pyramidal Neurons. Neuron 2019; 104:1081-1094.e7. [PMID: 31704028 PMCID: PMC6926483 DOI: 10.1016/j.neuron.2019.09.027] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/11/2019] [Accepted: 09/17/2019] [Indexed: 12/14/2022]
Abstract
Fine orchestration of excitatory and inhibitory synaptic development is required for normal brain function, and alterations may cause neurodevelopmental disorders. Using sparse molecular manipulations in intact brain circuits, we show that the glutamate receptor delta-1 (GluD1), a member of ionotropic glutamate receptors (iGluRs), is a postsynaptic organizer of inhibitory synapses in cortical pyramidal neurons. GluD1 is selectively required for the formation of inhibitory synapses and regulates GABAergic synaptic transmission accordingly. At inhibitory synapses, GluD1 interacts with cerebellin-4, an extracellular scaffolding protein secreted by somatostatin-expressing interneurons, which bridges postsynaptic GluD1 and presynaptic neurexins. When binding to its agonist glycine or D-serine, GluD1 elicits non-ionotropic postsynaptic signaling involving the guanine nucleotide exchange factor ARHGEF12 and the regulatory subunit of protein phosphatase 1 PPP1R12A. Thus, GluD1 defines a trans-synaptic interaction regulating postsynaptic signaling pathways for the proper establishment of cortical inhibitory connectivity and challenges the dichotomy between iGluRs and inhibitory synaptic molecules.
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Affiliation(s)
- Matteo Fossati
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 75005 Paris, France
| | - Nora Assendorp
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 75005 Paris, France
| | - Olivier Gemin
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 75005 Paris, France
| | - Sabrina Colasse
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 75005 Paris, France
| | - Florent Dingli
- Institut Curie, PSL Research University, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, 75248 Paris Cedex 05, France
| | - Guillaume Arras
- Institut Curie, PSL Research University, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, 75248 Paris Cedex 05, France
| | - Damarys Loew
- Institut Curie, PSL Research University, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, 75248 Paris Cedex 05, France
| | - Cécile Charrier
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, 75005 Paris, France.
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104
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Suppression of Presynaptic Glutamate Release by Postsynaptic Metabotropic NMDA Receptor Signalling to Pannexin-1. J Neurosci 2019; 40:729-742. [PMID: 31818976 DOI: 10.1523/jneurosci.0257-19.2019] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 11/26/2019] [Accepted: 12/03/2019] [Indexed: 01/22/2023] Open
Abstract
The impact of pannexin-1 (Panx1) channels on synaptic transmission is poorly understood. Here, we show that selective block of Panx1 in single postsynaptic hippocampal CA1 neurons from male rat or mouse brain slices causes intermittent, seconds long increases in the frequency of sEPSC following Schaffer collateral stimulation. The increase in sEPSC frequency occurred without an effect on evoked neurotransmission. Consistent with a presynaptic origin of the augmented glutamate release, the increased sEPSC frequency was prevented by bath-applied EGTA-AM or TTX. Manipulation of a previously described metabotropic NMDAR pathway (i.e., by preventing ligand binding to NMDARs with competitive antagonists or blocking downstream Src kinase) also increased sEPSC frequency similar to that seen when Panx1 was blocked. This facilitated glutamate release was absent in transient receptor potential vanilloid 1 (TRPV1) KO mice and prevented by the TRPV1 antagonist, capsazepine, suggesting it required presynaptic TRPV1. We show presynaptic expression of TRPV1 by immunoelectron microscopy and link TRPV1 to Panx1 because Panx1 block increases tissue levels of the endovanilloid, anandamide. Together, these findings demonstrate an unexpected role for metabotropic NMDARs and postsynaptic Panx1 in suppression of facilitated glutamate neurotransmission.SIGNIFICANCE STATEMENT The postsynaptic ion and metabolite channel, pannexin-1, is regulated by metabotropic NMDAR signaling through Src kinase. This pathway suppresses facilitated release of presynaptic glutamate during synaptic activity by regulating tissue levels of the transient receptor potential vanilloid 1 agonist anandamide.
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105
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Faldini E, Ahmed T, Bueé L, Blum D, Balschun D. Tau- but not Aß -pathology enhances NMDAR-dependent depotentiation in AD-mouse models. Acta Neuropathol Commun 2019; 7:202. [PMID: 31815648 PMCID: PMC6902514 DOI: 10.1186/s40478-019-0813-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 09/22/2019] [Indexed: 11/10/2022] Open
Abstract
Many mouse models of Alzheimer's disease (AD) exhibit impairments in hippocampal long-term-potentiation (LTP), seemingly corroborating the strong correlation between synaptic loss and cognitive decline reported in human studies. In other AD mouse models LTP is unaffected, but other defects in synaptic plasticity may still be present. We recently reported that THY-Tau22 transgenic mice, that overexpress human Tau protein carrying P301S and G272 V mutations and show normal LTP upon high-frequency-stimulation (HFS), develop severe changes in NMDAR mediated long-term-depression (LTD), the physiological counterpart of LTP. In the present study, we focused on putative effects of AD-related pathologies on depotentiation (DP), another form of synaptic plasticity. Using a novel protocol to induce DP in the CA1-region, we found in 11-15 months old male THY-Tau22 and APPPS1-21 transgenic mice that DP was not deteriorated by Aß pathology while significantly compromised by Tau pathology. Our findings advocate DP as a complementary form of synaptic plasticity that may help in elucidating synaptic pathomechanisms associated with different types of dementia.
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106
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Kruijssen DLH, Wierenga CJ. Single Synapse LTP: A Matter of Context? Front Cell Neurosci 2019; 13:496. [PMID: 31780899 PMCID: PMC6861208 DOI: 10.3389/fncel.2019.00496] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 10/21/2019] [Indexed: 12/18/2022] Open
Abstract
The most commonly studied form of synaptic plasticity is long-term potentiation (LTP). Over the last 15 years, it has been possible to induce structural and functional LTP in dendritic spines using two-photon glutamate uncaging, allowing for studying the signaling mechanisms of LTP with single synapse resolution. In this review, we compare different stimulation methods to induce single synapse LTP and discuss how LTP is expressed. We summarize the underlying signaling mechanisms that have been studied with high spatiotemporal resolution. Finally, we discuss how LTP in a single synapse can be affected by excitatory and inhibitory synapses nearby. We argue that single synapse LTP is highly dependent on context: the choice of induction method, the history of the dendritic spine and the dendritic vicinity crucially affect signaling pathways and expression of single synapse LTP.
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Affiliation(s)
- Dennis L H Kruijssen
- Department of Biology, Science for Life, Utrecht University, Utrecht, Netherlands
| | - Corette J Wierenga
- Department of Biology, Science for Life, Utrecht University, Utrecht, Netherlands
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107
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Early TLR4 inhibition reduces hippocampal injury at puberty in a rat model of neonatal hypoxic-ischemic brain damage via regulation of neuroimmunity and synaptic plasticity. Exp Neurol 2019; 321:113039. [PMID: 31442443 DOI: 10.1016/j.expneurol.2019.113039] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 08/08/2019] [Accepted: 08/19/2019] [Indexed: 12/30/2022]
Abstract
Neonatal hypoxic-ischemic brain damage (HIBD) survivors present with long-term neurological disorders affecting their quality of life, and there remains a lack of effective treatment. Toll-like receptor 4 (TLR4) is widely distributed in nerve cells and its inhibition has a neuroprotective effect against brain injury. The present study aimed to evaluate the long-term neuroprotective effects of early inhibition of TLR4 during HIBD. Seven-day-old rat pups were subjected to left carotid artery ligation followed by 2 h of hypoxia (8.0% O2). A single dose of TAK-242 (0.5 mg/kg), a TLR4-specific antagonist, was intraperitoneally injected half an hour prior to hypoxic ischemia (HI). The long-term effects of TAK-242 inhibition on the induced hippocampal injury were investigated by assessing behaviour at P28, and then using a variety of methods to exploring the mechanism, including immunofluorescence, Golgi silver staining, Western blotting and real-time polymerase chain reaction (RT-PCR). TAK-242 treatment significantly reduced the expression levels of TLR4 and its downstream signalling molecules in the ipsilateral lesion of the hippocampus 24 h after HIBD. The Morris water maze (MWM) test demonstrated that TAK-242 treatment reduced the loss of HI-induced learning and memory functions. Immunofluorescence experiments showed that TAK-242 administration attenuated HI-induced loss of neurons, prevented the activation of microglia and astrocytes, and increased the expression of the glutamate receptor subtype, N-methyl d-aspartate 2A (NR2A) in the ipsilateral hippocampus region. Golgi silver staining revealed that TAK-242 prevented an HI-induced decline in spine density in the ipsilateral hippocampus. Western blot and RT-PCR results indicated that the expression of NR2A protein and mRNA in the ipsilateral hippocampi of adolescent rats decreased after neonatal HIBD; early TAK-242 administration may reverse these effects. In conclusion, our findings indicate that early inhibition of TLR4 signalling may improve the long-term prognosis of neonatal HIBD. The mechanisms contributing to this improvement involve reductions in neuronal loss, a decrease in glial cell activation, and an improvement in synaptic plasticity.
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108
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Reiner A, Levitz J. Glutamatergic Signaling in the Central Nervous System: Ionotropic and Metabotropic Receptors in Concert. Neuron 2019; 98:1080-1098. [PMID: 29953871 DOI: 10.1016/j.neuron.2018.05.018] [Citation(s) in RCA: 360] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/19/2018] [Accepted: 05/10/2018] [Indexed: 12/28/2022]
Abstract
Glutamate serves as both the mammalian brain's primary excitatory neurotransmitter and as a key neuromodulator to control synapse and circuit function over a wide range of spatial and temporal scales. This functional diversity is decoded by two receptor families: ionotropic glutamate receptors (iGluRs) and metabotropic glutamate receptors (mGluRs). The challenges posed by the complexity and physiological importance of each of these subtypes has limited our appreciation and understanding of how these receptors work in concert. In this review, by comparing both receptor families with a focus on their crosstalk, we argue for a more holistic understanding of neural glutamate signaling.
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Affiliation(s)
- Andreas Reiner
- Department of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany.
| | - Joshua Levitz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA.
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109
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Zheng Y, Cheng J, Dong L, Ma X, Kong Q. Effects of exposure to extremely low frequency electromagnetic fields on hippocampal long-term potentiation in hippocampal CA1 region. Biochem Biophys Res Commun 2019; 517:513-519. [PMID: 31376941 DOI: 10.1016/j.bbrc.2019.07.085] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 07/22/2019] [Indexed: 11/17/2022]
Abstract
Exposure to environmental electromagnetic fields, especially to the extremely low-frequency (ELF < 300 Hz) electromagnetic fields (EMFs) might produce modulation effects on neuronal activity. Long-term changes in synaptic plasticity such as long-term potentiation (LTP) involved in learning and memory may have contributions to a number of neurological diseases. However, the modulation effects of ELF-EMFs on LTP are not yet fully understood. In our present study, we aimed to evaluate the effects of exposure to ELF-EMFs on LTP in hippocampal CA1 region in rats. Hippocampal slices were exposed to magnetic fields generated by sXcELF system with different frequencies (15, 50, and 100 Hz [Hz]), intensities (0.5, 1, and 2 mT [mT]), and duration (10 s [s], 20 s, 40 s, 60 s, and 5 min), then the baseline signal recordings for 20 min and the evoked field excitatory postsynaptic potentials (fEPSPs) were recorded. We found that the LTP amplitudes decreased after magnetic field exposure, and the LTP amplitudes decreased in proportion to exposure doses and durations, suggesting ELF-EMFs may have dose and duration-dependent inhibition effects. Among multiple exposure duration and doses combinations, upon 5 min magnetic field exposure, 15 Hz/2 mT maximally inhibited LTP. Under 15 Hz/2 mT ELF-EMFs, LTP amplitude decreases in proportion to the length of exposure durations within 5 min time frame. Our findings illustrated the potential effects of ELF-EMFs on synaptic plasticity and will lead to better understanding of the influence on learning and memory.
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Affiliation(s)
- Yu Zheng
- School of Electronics and Information Engineering, Tianjin Polytechnic University, Tianjin, 300387, China.
| | - Jianhao Cheng
- School of Electronics and Information Engineering, Tianjin Polytechnic University, Tianjin, 300387, China
| | - Lei Dong
- State Key Laboratory of Precision Measurement Technology and Instruments, Tianjin University, Tianjin, 300072, China
| | - Xiaoxu Ma
- School of Electronics and Information Engineering, Tianjin Polytechnic University, Tianjin, 300387, China
| | - Qingyao Kong
- Department of Anesthesia and Critical Care, University of Chicago, Chicago, IL, USA
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110
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Tau binding protein CAPON induces tau aggregation and neurodegeneration. Nat Commun 2019; 10:2394. [PMID: 31160584 PMCID: PMC6546774 DOI: 10.1038/s41467-019-10278-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 04/24/2019] [Indexed: 02/07/2023] Open
Abstract
To understand the molecular processes that link Aβ amyloidosis, tauopathy and neurodegeneration, we screened for tau-interacting proteins by immunoprecipitation/LC-MS. We identified the carboxy-terminal PDZ ligand of nNOS (CAPON) as a novel tau-binding protein. CAPON is an adaptor protein of neuronal nitric oxide synthase (nNOS), and activated by the N-methyl-D-aspartate receptor. We observed accumulation of CAPON in the hippocampal pyramidal cell layer in the AppNL-G-F -knock-in (KI) brain. To investigate the effect of CAPON accumulation on Alzheimer’s disease (AD) pathogenesis, CAPON was overexpressed in the brain of AppNL-G-F mice crossbred with MAPT (human tau)-KI mice. This produced significant hippocampal atrophy and caspase3-dependent neuronal cell death in the CAPON-expressing hippocampus, suggesting that CAPON accumulation increases neurodegeneration. CAPON expression also induced significantly higher levels of phosphorylated, oligomerized and insoluble tau. In contrast, CAPON deficiency ameliorated the AD-related pathological phenotypes in tauopathy model. These findings suggest that CAPON could be a druggable AD target. To understand the molecular processes that link Aβ amyloidosis, tauopathy and neurodegeneration, the authors screened for tau-interacting proteins. They demonstrated that a novel tau binding protein CAPON accelerates tau pathology and neuronal cell death in an Alzheimer’s disease mouse model.
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111
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Circuit-specific control of the medial entorhinal inputs to the dentate gyrus by atypical presynaptic NMDARs activated by astrocytes. Proc Natl Acad Sci U S A 2019; 116:13602-13610. [PMID: 31152131 PMCID: PMC6612919 DOI: 10.1073/pnas.1816013116] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Here, we investigated the properties of presynaptic N-methyl-d-aspartate receptors (pre-NMDARs) at corticohippocampal excitatory connections between perforant path (PP) afferents and dentate granule cells (GCs), a circuit involved in memory encoding and centrally affected in Alzheimer's disease and temporal lobe epilepsy. These receptors were previously reported to increase PP release probability in response to gliotransmitters released from astrocytes. Their activation occurred even under conditions of elevated Mg2+ and lack of action potential firing in the axons, although how this could be accomplished was unclear. We now report that these pre-NMDARs contain the GluN3a subunit conferring them low Mg2+ sensitivity. GluN3a-containing NMDARs at PP-GC synapses are preponderantly presynaptic vs. postsynaptic and persist beyond the developmental period. Moreover, they are expressed selectively at medial-not lateral-PP axons and act to functionally enhance release probability specifically of the medial perforant path (MPP) input to GC dendrites. By controlling release probability, GluN3a-containing pre-NMDARs also control the dynamic range for long-term potentiation (LTP) at MPP-GC synapses, an effect requiring Ca2+ signaling in astrocytes. Consistent with the functional observations, GluN3a subunits in MPP terminals are localized at sites away from the presynaptic release sites, often facing astrocytes, in line with a primary role for astrocytic inputs in their activation. Overall, GluN3A-containing pre-NMDARs emerge as atypical modulators of dendritic computations in the MPP-GC memory circuit.
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112
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Metzbower SR, Joo Y, Benavides DR, Blanpied TA. Properties of Individual Hippocampal Synapses Influencing NMDA-Receptor Activation by Spontaneous Neurotransmission. eNeuro 2019; 6:ENEURO.0419-18.2019. [PMID: 31110134 PMCID: PMC6541874 DOI: 10.1523/eneuro.0419-18.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 05/05/2019] [Accepted: 05/12/2019] [Indexed: 12/14/2022] Open
Abstract
NMDA receptor (NMDAR) activation is critical for maintenance and modification of synapse strength. Specifically, NMDAR activation by spontaneous glutamate release has been shown to mediate some forms of synaptic plasticity as well as synaptic development. Interestingly, there is evidence that within individual synapses each release mode may be segregated such that postsynaptically there are distinct pools of responsive receptors. To examine potential regulators of NMDAR activation because of spontaneous glutamate release in cultured hippocampal neurons, we used GCaMP6f imaging at single synapses in concert with confocal and super-resolution imaging. Using these single-spine approaches, we found that Ca2+ entry activated by spontaneous release tends to be carried by GluN2B-NMDARs. Additionally, the amount of NMDAR activation varies greatly both between synapses and within synapses, and is unrelated to spine and synapse size, but does correlate loosely with synapse distance from the soma. Despite the critical role of spontaneous activation of NMDARs in maintaining synaptic function, their activation seems to be controlled factors other than synapse size or synapse distance from the soma. It is most likely that NMDAR activation by spontaneous release influenced variability in subsynaptic receptor position, release site position, vesicle content, and channel properties. Therefore, spontaneous activation of NMDARs appears to be regulated distinctly from other receptor types, notably AMPARs, within individual synapses.
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Affiliation(s)
| | - Yuyoung Joo
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland, 21201
| | - David R Benavides
- Department of Neurology, University of Maryland School of Medicine, Baltimore, Maryland, 21201
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113
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O'Riordan KJ, Hu NW, Rowan MJ. Aß Facilitates LTD at Schaffer Collateral Synapses Preferentially in the Left Hippocampus. Cell Rep 2019; 22:2053-2065. [PMID: 29466733 DOI: 10.1016/j.celrep.2018.01.085] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 12/16/2017] [Accepted: 01/26/2018] [Indexed: 01/03/2023] Open
Abstract
Promotion of long-term depression (LTD) mechanisms by synaptotoxic soluble oligomers of amyloid-β (Aß) has been proposed to underlie synaptic dysfunction in Alzheimer's disease (AD). Previously, LTD was induced by relatively non-specific electrical stimulation. Exploiting optogenetics, we studied LTD using a more physiologically diffuse spatial pattern of selective pathway activation in the rat hippocampus in vivo. This relatively sparse synaptic LTD requires both the ion channel function and GluN2B subunit of the NMDA receptor but, in contrast to electrically induced LTD, is not facilitated by boosting endogenous muscarinic acetylcholine or metabotropic glutamate 5 receptor activation. Although in the absence of Aß, there is no evidence of hippocampal LTD asymmetry, in the presence of Aß, the induction of LTD is preferentially enhanced in the left hippocampus in an mGluR5-dependent manner. This circuit-selective disruption of synaptic plasticity by Aß provides a route to understanding the development of aberrant brain lateralization in AD.
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Affiliation(s)
- Kenneth J O'Riordan
- Department of Pharmacology and Therapeutics and Institute of Neuroscience, Watts Building, Trinity College, Dublin 2, Ireland
| | - Neng-Wei Hu
- Department of Pharmacology and Therapeutics and Institute of Neuroscience, Watts Building, Trinity College, Dublin 2, Ireland; Department of Gerontology, Yijishan Hospital, Wannan Medical College, Wuhu, China.
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics and Institute of Neuroscience, Watts Building, Trinity College, Dublin 2, Ireland.
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114
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Mateos-Aparicio P, Rodríguez-Moreno A. The Impact of Studying Brain Plasticity. Front Cell Neurosci 2019; 13:66. [PMID: 30873009 PMCID: PMC6400842 DOI: 10.3389/fncel.2019.00066] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/11/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Pedro Mateos-Aparicio
- Department of Physiology, Anatomy and Cell Biology, University Pablo de Olavide, Seville, Spain
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115
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Liu J, Chang L, Song Y, Li H, Wu Y. The Role of NMDA Receptors in Alzheimer's Disease. Front Neurosci 2019; 13:43. [PMID: 30800052 PMCID: PMC6375899 DOI: 10.3389/fnins.2019.00043] [Citation(s) in RCA: 234] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 01/16/2019] [Indexed: 12/13/2022] Open
Abstract
In Alzheimer’s disease (AD), early synaptic dysfunction is associated with the increased oligomeric amyloid-beta peptide, which causes NMDAR-dependent synaptic depression and spine elimination. Memantine, low-affinity NMDAR channel blocker, has been used in the treatment of moderate to severe AD. However, clear evidence is still deficient in demonstrating the underlying mechanisms and a relationship between NMDARs dysfunction and AD. This review focuses on not only changes in expression of different NMDAR subunits, but also some unconventional modes of NMDAR action.
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Affiliation(s)
- Jinping Liu
- School of Medicine, Tsinghua University, Beijing, China
| | - Lirong Chang
- Department of Anatomy, Ministry of Science and Technology Laboratory of Brain Disorders, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Yizhi Song
- Department of Anatomy, Ministry of Science and Technology Laboratory of Brain Disorders, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Hui Li
- Department of Anatomy, Ministry of Science and Technology Laboratory of Brain Disorders, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Yan Wu
- Department of Anatomy, Ministry of Science and Technology Laboratory of Brain Disorders, Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
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Skowrońska K, Obara-Michlewska M, Zielińska M, Albrecht J. NMDA Receptors in Astrocytes: In Search for Roles in Neurotransmission and Astrocytic Homeostasis. Int J Mol Sci 2019; 20:ijms20020309. [PMID: 30646531 PMCID: PMC6358855 DOI: 10.3390/ijms20020309] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 01/08/2019] [Accepted: 01/10/2019] [Indexed: 12/15/2022] Open
Abstract
Studies of the last two decades have demonstrated the presence in astrocytic cell membranes of N-methyl-d-aspartate (NMDA) receptors (NMDARs), albeit their apparently low abundance makes demonstration of their presence and function more difficult than of other glutamate (Glu) receptor classes residing in astrocytes. Activation of astrocytic NMDARs directly in brain slices and in acutely isolated or cultured astrocytes evokes intracellular calcium increase, by mutually unexclusive ionotropic and metabotropic mechanisms. However, other than one report on the contribution of astrocyte-located NMDARs to astrocyte-dependent modulation of presynaptic strength in the hippocampus, there is no sound evidence for the significant role of astrocytic NMDARs in astrocytic-neuronal interaction in neurotransmission, as yet. Durable exposure of astrocytic and neuronal co-cultures to NMDA has been reported to upregulate astrocytic synthesis of glutathione, and in this way to increase the antioxidative capacity of neurons. On the other hand, overexposure to NMDA decreases, by an as yet unknown mechanism, the ability of cultured astrocytes to express glutamine synthetase (GS), aquaporin-4 (AQP4), and the inward rectifying potassium channel Kir4.1, the three astroglia-specific proteins critical for homeostatic function of astrocytes. The beneficial or detrimental effects of astrocytic NMDAR stimulation revealed in the in vitro studies remain to be proven in the in vivo setting.
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Affiliation(s)
- Katarzyna Skowrońska
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego Str., 02-106 Warsaw, Poland.
| | - Marta Obara-Michlewska
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego Str., 02-106 Warsaw, Poland.
| | - Magdalena Zielińska
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego Str., 02-106 Warsaw, Poland.
| | - Jan Albrecht
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego Str., 02-106 Warsaw, Poland.
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Keith RE, Azcarate JM, Keith MJ, Hung CW, Badakhsh MF, Dumas TC. Direct Intracellular Signaling by the Carboxy terminus of NMDA Receptor GluN2 Subunits Regulates Dendritic Morphology in Hippocampal CA1 Pyramidal Neurons. Neuroscience 2019; 396:138-153. [PMID: 30471357 PMCID: PMC6311441 DOI: 10.1016/j.neuroscience.2018.11.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 10/16/2018] [Accepted: 11/14/2018] [Indexed: 12/22/2022]
Abstract
N-methyl-d-aspartate receptors (NMDARs) are glutamatergic receptors that take part in excitatory synaptic transmission and drive functional and structural neuronal plasticity, including activity-dependent changes in dendritic morphology. Forebrain NMDARs contribute to neuronal plasticity in at least two ways: through calcium-mediated processes or via direct intracellular postsynaptic signaling. Both properties are regulated by the GluN2 subunits. However, the separate contributions of these properties to the regulation of dendritic morphology are unknown. We created transgenic mice that express chimeric GluN2 subunits and examined the impact on pyramidal cell dendritic morphology in hippocampal region CA1. Golgi-Cox impregnation and transgenic expression of green fluorescent protein were employed to visualize dendritic arbors. In adult mice with a predominantly native GluN2A background, overexpression of the GluN2B carboxy terminus increased the total path of the dendritic arbor without affecting branch number or tortuosity. Overexpressing the amino terminus and transmembrane domains of GluN2B had little effect. It may be inferred from these results that NMDAR-dependent intracellular signaling regulates dendritic morphology of hippocampal pyramidal cells more so than calcium conductance dynamics. The findings add to the understanding of NMDAR-mediated signaling in hippocampal neurons and support re-investigation of the molecular underpinnings of NMDAR involvement in postnatal dendrite maturation.
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Affiliation(s)
- Rachel E Keith
- Interdisciplinary Program in Neuroscience, George Mason University, Fairfax, VA 22030, United States; Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States
| | - Jessica M Azcarate
- Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States
| | - Matthew J Keith
- Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States
| | - Carey W Hung
- Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States
| | - Maryam F Badakhsh
- Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States
| | - Theodore C Dumas
- Psychology Department, George Mason University, Fairfax, VA 22030, United States; Interdisciplinary Program in Neuroscience, George Mason University, Fairfax, VA 22030, United States; Krasnow Institute of Advanced Study, George Mason University, Fairfax, VA 22030, United States.
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118
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Minnella AM, Zhao JX, Jiang X, Jakobsen E, Lu F, Wu L, El-Benna J, Gray JA, Swanson RA. Excitotoxic superoxide production and neuronal death require both ionotropic and non-ionotropic NMDA receptor signaling. Sci Rep 2018; 8:17522. [PMID: 30504838 PMCID: PMC6269523 DOI: 10.1038/s41598-018-35725-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 11/07/2018] [Indexed: 12/12/2022] Open
Abstract
NMDA-type glutamate receptors (NMDAR) trigger superoxide production by neuronal NADPH oxidase-2 (NOX2), which if sustained leads to cell death. This process involves Ca2+ influx through NMDAR channels. By contrast, comparable Ca2+ influx by other routes does not induce NOX2 activation or cell death. This contrast has been attributed to site-specific effects of Ca2+ flux through NMDAR. Here we show instead that it stems from non-ionotropic signaling by NMDAR GluN2B subunits. To evaluate non-ionotropic effects, mouse cortical neurons were treated with NMDA together with 7-chlorokynurenate, L-689,560, or MK-801, which block Ca2+ influx through NMDAR channels but not NMDA binding. NMDA-induced superoxide formation was prevented by the channel blockers, restored by concurrent Ca2+ influx through ionomycin or voltage-gated calcium channels, and not induced by the Ca2+ influx in the absence of NMDAR ligand binding. Neurons expressing either GluN2B subunits or chimeric GluN2A/GluN2B C-terminus subunits exhibited NMDA-induced superoxide production, whereas neurons expressing chimeric GluN2B/GluN2A C-terminus subunits did not. Neuronal NOX2 activation requires phosphoinositide 3-kinase (PI3K), and NMDA binding to NMDAR increased PI3K association with NMDA GluN2B subunits independent of Ca2+ influx. These findings identify a non-ionotropic signaling pathway that links NMDAR to NOX2 activation through the C-terminus domain of GluN2B.
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Affiliation(s)
- Angela M Minnella
- Department of Neurology, University of California, San Francisco, San Francisco, CA, 94122, USA.,San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
| | - Jerry X Zhao
- Department of Neurology, University of California, San Francisco, San Francisco, CA, 94122, USA.,San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
| | - Xiangning Jiang
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Emil Jakobsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2100, Denmark
| | - Fuxin Lu
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Long Wu
- Department of Neurology, University of California, San Francisco, San Francisco, CA, 94122, USA.,San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA
| | - Jamel El-Benna
- INSERM-U1149, CNRS-ERL8252, Centre de Recherche sur l'Inflammation, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Laboratoire d'Excellence Inflamex, Faculté de Médecine, Site Xavier Bichat, Paris, France
| | - John A Gray
- Center for Neuroscience and Department of Neurology, University of California Davis, Davis, CA, 95618, USA
| | - Raymond A Swanson
- Department of Neurology, University of California, San Francisco, San Francisco, CA, 94122, USA. .,San Francisco Veterans Affairs Medical Center, San Francisco, CA, 94121, USA.
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Montes de Oca Balderas P. Flux-Independent NMDAR Signaling: Molecular Mediators, Cellular Functions, and Complexities. Int J Mol Sci 2018; 19:ijms19123800. [PMID: 30501045 PMCID: PMC6321296 DOI: 10.3390/ijms19123800] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 11/16/2018] [Accepted: 11/19/2018] [Indexed: 12/21/2022] Open
Abstract
The glutamate (Glu) N-methyl-d-aspartate (NMDA) receptor (NMDAR) plays a critical role in synaptic communication given mainly by its ionotropic function that permeates Ca2+. This in turn activates calmodulin that triggers CaMKII, MAPK, CREB, and PI3K pathways, among others. However, NMDAR signaling is more complex. In the last two decades several groups have shown that the NMDAR also elicits flux-independent signaling (f-iNMDARs). It has been demonstrated that agonist (Glu or NMDA) or co-agonist (Glycine or d-Serine) bindings initiate intracellular events, including conformational changes, exchange of molecular interactions, release of second messengers, and signal transduction, that result in different cellular events including endocytosis, LTD, cell death, and neuroprotection, among others. Interestingly, f-iNMDARs has also been observed in pathological conditions and non-neuronal cells. Here, the molecular and cellular events elicited by these flux-independent actions (non-canonical or metabotropic-like) of the NMDAR are reviewed. Considering the NMDAR complexity, it is possible that these flux-independent events have a more relevant role in intracellular signaling that has been disregarded for decades. Moreover, considering the wide expression and function of the NMDAR in non-neuronal cells and other tissues beyond the nervous system and some evolutionary traits, f-iNMDARs calls for a reconsideration of how we understand the biology of this complex receptor.
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Affiliation(s)
- Pavel Montes de Oca Balderas
- Departamento de Neurociencia Cognitiva, Instituto de Fisiología Celular, UNAM. Av. Universidad 3000, C.U. Coyoacán, Ciudad de México. C.P. 04510, Mexico.
- Unidad de Neurobiología Dinámica, Departamento de Neuroquímica, INNN. Av. Insurgentes Sur #3877 Col. La Fama, Ciudad de México. C.P. 14269, Mexico.
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Mansilla A, Jordán-Álvarez S, Santana E, Jarabo P, Casas-Tintó S, Ferrús A. Molecular mechanisms that change synapse number. J Neurogenet 2018; 32:155-170. [DOI: 10.1080/01677063.2018.1506781] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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121
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Zhang JJ, Haubrich J, Bernabo M, Finnie PS, Nader K. Limits on lability: Boundaries of reconsolidation and the relationship to metaplasticity. Neurobiol Learn Mem 2018; 154:78-86. [DOI: 10.1016/j.nlm.2018.02.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/08/2018] [Accepted: 02/19/2018] [Indexed: 02/07/2023]
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A conserved glycine harboring disease-associated mutations permits NMDA receptor slow deactivation and high Ca 2+ permeability. Nat Commun 2018; 9:3748. [PMID: 30217972 PMCID: PMC6138751 DOI: 10.1038/s41467-018-06145-w] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 08/13/2018] [Indexed: 02/07/2023] Open
Abstract
A variety of de novo and inherited missense mutations associated with neurological disorders are found in the NMDA receptor M4 transmembrane helices, which are peripheral to the pore domain in eukaryotic ionotropic glutamate receptors. Subsets of these mutations affect receptor gating with dramatic effects, including in one instance halting it, occurring at a conserved glycine near the extracellular end of M4. Functional experiments and molecular dynamic simulations of constructs with and without substitutions at this glycine indicate that it acts as a hinge, permitting the intracellular portion of the ion channel to laterally expand. This expansion stabilizes long-lived open states leading to slow deactivation and high Ca2+ permeability. Our studies provide a functional and structural framework for the effect of missense mutations on NMDARs at central synapses and highlight how the M4 segment may represent a pathway for intracellular modulation of NMDA receptor function. Little is known about the impact of de novo and inherited missense mutations in the NMDA receptor M4 transmembrane helices. In this study, the authors use functional and computational approaches to demonstrate how mutations to conserved glycine sites within this region cause structural rearrangement, altered receptor deactivation and calcium permeability.
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Pharris MC, Patel NM, Kinzer-Ursem TL. Competitive Tuning Among Ca 2+/Calmodulin-Dependent Proteins: Analysis of in silico Model Robustness and Parameter Variability. Cell Mol Bioeng 2018; 11:353-365. [PMID: 31105797 DOI: 10.1007/s12195-018-0549-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Introduction Calcium/Calmodulin-dependent (Ca2+/CaM-dependent) regulation of protein signaling has long been recognized for its importance in a number of physiological contexts. Found in almost all eukaryotic cells, Ca2+/CaM-dependent signaling participates in muscle development, immune responses, cardiac myocyte function and regulation of neuronal connectivity. In excitatory neurons, dynamic changes in the strength of synaptic connections, known as synaptic plasticity, occur when calcium ions (Ca2+) flux through NMDA receptors and bind the Ca2+-sensor calmodulin (CaM). Ca2+/CaM, in turn, regulates downstream protein signaling in actin polymerization, receptor trafficking, and transcription factor activation.The activation of downstream Ca2+/CaM-dependent binding proteins (CBPs) is a function of the frequency of Ca2+ flux, such that each CBP is preferentially "tuned" to different Ca2+ input signals. We have recently reported that competition among CBPs for CaM binding is alone sufficient to recreate in silico the observed in vivo frequency-dependence of several CBPs. However, CBP activation may strongly depend on the identity and concentration of proteins that constitute the competitive pool; with important implications in the regulation of CBPs in both normal and disease states. Methods Here, we extend our previous deterministic model of competition among CBPs to include phosphodiesterases, AMPAR receptors that are important in synaptic plasticity, and enzymatic function of CBPs: cAMP regulation, kinase activity, and phosphatase activity. After rigorous parameterization and validation by global sensitivity analysis using Latin Hypercube Sampling (LHS) and Partial Rank Correlation Coefficients (PRCC), we explore how perturbing the competitive pool of CBPs influences downstream signaling events. In particular, we hypothesize that although perturbations may decrease activation of one CBP, increased activation of a separate, but enzymatically-related CBP could compensate for this loss, providing a homeostatic effect. Results and Conclusions First we compare dynamic model output of two models: a two-state model of Ca2+/CaM binding and a four-state model of Ca2+/CaM binding. We find that a four-state model of Ca2+/CaM binding best captures the dynamic nature of the rapid response of CaM and CBPs to Ca2+ flux in the system. Using global sensitivity analysis, we find that model output is robust to parameter variability. Indeed, although variations in the expression of the CaM buffer neurogranin (Ng) may cause a decrease in Ca2+/CaM-dependent kinase II (CaMKII) activation, overall AMPA receptor phosphorylation is preserved; ostensibly by a concomitant increase in adenylyl cyclase 8 (AC8)-mediated activation of protein kinase A (PKA). Indeed phosphorylation of AMPAR receptors by CaMKII and PKA is robust across a wide range of Ng concentrations, though increases in AMPAR phosphorylation is seen at low Ng levels approaching zero. Our results may explain recent counter-intuitive results in neurogranin knockout mice and provide further evidence that competitive tuning is an important mechanism in synaptic plasticity. These results may be readily translated to other Ca2+/CaM-dependent signaling systems in other cell types and can be used to suggest targeted experimental investigation to explain counter-intuitive or unexpected downstream signaling outcomes.Tamara Kinzer-Ursem is an Assistant Professor in the Weldon School of Biomedical Engineering. She received her B.S. in Bioengineering from the University of Toledo and her M.S. and Ph.D. degrees in Chemical Engineering from the University of Michigan, and her post-doctoral training in Molecular Neuroscience at the California Institute of Technology. Prior to joining Purdue she was the Head of R&D in Biochemistry at Maven Biotechnologies and Visiting Associate in Chemical Engineering at the California Institute of Technology.Research in the Kinzer-Ursem lab focuses on developing tools to advance quantitative descriptions of cellular processes and disease within three areas of expertise: 1) Using particle diffusivity measurements to quantify biomolecular processes. Particle diffusometry is being used as a sensitive biosensor to detect the presence of pathogens in environmental and patient samples. 2) Development of novel protein tagging technologies that are used to label proteins in vivo to enable quantitative description of protein function and elucidate disease mechanisms. 3) Computational modeling of signal transduction mechanisms to understand cellular processes. Using computational techniques, we have recently described "competitive tuning" as a mechanism that might be used to regulate information transfer through protein networks, with implications in cell behavior and drug target analysis.
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Affiliation(s)
- Matthew C Pharris
- Weldon School of Biomedical Engineering, Purdue University, 260 South Martin Jischke Drive, West Lafayette, IN 47907 USA
| | - Neal M Patel
- Weldon School of Biomedical Engineering, Purdue University, 260 South Martin Jischke Drive, West Lafayette, IN 47907 USA
| | - Tamara L Kinzer-Ursem
- Weldon School of Biomedical Engineering, Purdue University, 260 South Martin Jischke Drive, West Lafayette, IN 47907 USA
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124
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Wu Y, Chen C, Yang Q, Jiao M, Qiu S. Endocytosis of GluN2B-containing NMDA receptors mediates NMDA-induced excitotoxicity. Mol Pain 2018; 13:1744806917701921. [PMID: 28326942 PMCID: PMC5391130 DOI: 10.1177/1744806917701921] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Abstract N-methyl-D-aspartate (NMDA) receptor overactivation is involved in neuronal damage after stroke. However, the mechanism underlying NMDA receptor-mediated excitotoxicity remains unclear. In this study, we confirmed that excessive activation of NMDARs led to cell apoptosis in PC12 cells and in primary cultured cortical neurons, which was mediated predominantly by the GluN2B-containing, but not the GluN2A-containing NMDARs. In addition, Clathrin-dependent endocytosis participated in NMDA-induced excitotoxicity. Furthermore, we identified that GluN2B-containing NMDARs underwent endocytosis during excessive NMDA treatment. Peptides specifically disrupting the interaction between GluN2B and AP-2 complex not only blocked endocytosis of GluN2B induced by NMDA treatment but also abolished NMDA-induced excitotoxicity. These results demonstrate that Clathrin-dependent endocytosis of GluN2B-containing NMDARs is critical to NMDA-induced excitotoxicity in PC12 cells and in primary cultured cortical neurons, and therefore provide a novel target for blocking NMDAR-mediated excitotoxicity.
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Affiliation(s)
- Yu Wu
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Changwan Chen
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qian Yang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Mingfei Jiao
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Shuang Qiu
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Shuang Qiu, Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China.
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125
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Abstract
The large-conductance calcium- and voltage-activated K+ (BK) channel has a requirement of high intracellular free Ca2+ concentrations for its activation in neurons under physiological conditions. The Ca2+ sources for BK channel activation are not well understood. In this study, we showed by coimmunopurification and colocalization analyses that BK channels form complexes with NMDA receptors (NMDARs) in both rodent brains and a heterologous expression system. The BK-NMDAR complexes are broadly present in different brain regions. The complex formation occurs between the obligatory BKα and GluN1 subunits likely via a direct physical interaction of the former's intracellular S0-S1 loop with the latter's cytosolic regions. By patch-clamp recording on mouse brain slices, we observed BK channel activation by NMDAR-mediated Ca2+ influx in dentate gyrus granule cells. BK channels modulate excitatory synaptic transmission via functional coupling with NMDARs at postsynaptic sites of medial perforant path-dentate gyrus granule cell synapses. A synthesized peptide of the BKα S0-S1 loop region, when loaded intracellularly via recording pipette, abolished the NMDAR-mediated BK channel activation and effect on synaptic transmission. These findings reveal the broad expression of the BK-NMDAR complexes in brain, the potential mechanism underlying the complex formation, and the NMDAR-mediated activation and function of postsynaptic BK channels in neurons.
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126
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Bouvier G, Larsen RS, Rodríguez-Moreno A, Paulsen O, Sjöström PJ. Towards resolving the presynaptic NMDA receptor debate. Curr Opin Neurobiol 2018; 51:1-7. [DOI: 10.1016/j.conb.2017.12.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/15/2017] [Accepted: 12/31/2017] [Indexed: 12/13/2022]
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127
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Zhang L, Zhang P, Wang G, Zhang H, Zhang Y, Yu Y, Zhang M, Xiao J, Crespo P, Hell JW, Lin L, Huganir RL, Zhu JJ. Ras and Rap Signal Bidirectional Synaptic Plasticity via Distinct Subcellular Microdomains. Neuron 2018; 98:783-800.e4. [PMID: 29706584 PMCID: PMC6192044 DOI: 10.1016/j.neuron.2018.03.049] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 02/12/2018] [Accepted: 03/27/2018] [Indexed: 11/16/2022]
Abstract
How signaling molecules achieve signal diversity and specificity is a long-standing cell biology question. Here we report the development of a targeted delivery method that permits specific expression of homologous Ras-family small GTPases (i.e., Ras, Rap2, and Rap1) in different subcellular microdomains, including the endoplasmic reticulum, lipid rafts, bulk membrane, lysosomes, and Golgi complex, in rodent hippocampal CA1 neurons. The microdomain-targeted delivery, combined with multicolor fluorescence protein tagging and high-resolution dual-quintuple simultaneous patch-clamp recordings, allows systematic analysis of microdomain-specific signaling. The analysis shows that Ras signals long-term potentiation via endoplasmic reticulum PI3K and lipid raft ERK, whereas Rap2 and Rap1 signal depotentiation and long-term depression via bulk membrane JNK and lysosome p38MAPK, respectively. These results establish an effective subcellular microdomain-specific targeted delivery method and unveil subcellular microdomain-specific signaling as the mechanism for homologous Ras and Rap to achieve signal diversity and specificity to control multiple forms of synaptic plasticity.
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Affiliation(s)
- Lei Zhang
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Peng Zhang
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Guangfu Wang
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Center for Life Sciences, School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Huaye Zhang
- Department of Microbiology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Center for Cell Signaling, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Yajun Zhang
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Yilin Yu
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Mingxu Zhang
- Department of Pharmacology, University of Iowa, Iowa City, IA 52242, USA; Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
| | - Jian Xiao
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China
| | - Piero Crespo
- Instituto de Biomedicina y Biotecnología de Cantabriaand CIBERONC, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Cantabria, Santander 39011, Spain
| | - Johannes W Hell
- Department of Pharmacology, University of Iowa, Iowa City, IA 52242, USA; Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
| | - Li Lin
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China.
| | - Richard L Huganir
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - J Julius Zhu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA 22908, USA; School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou 325035, China; School of Medicine, Ningbo University, Ningbo 315010, China; Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, 6525 EN, Nijmegen, the Netherlands
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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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129
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Abstract
Dynamic modification of synaptic connectivity in response to sensory experience is a vital step in the refinement of brain circuits as they are established during development and modified during learning. In addition to the well-established role for new spine growth and stabilization in the experience-dependent plasticity of neural circuits, dendritic spine elimination has been linked to improvements in learning, and dysregulation of spine elimination has been associated with intellectual disability and behavioral impairment. Proper brain function requires a tightly regulated balance between spine formation and spine elimination. Although most studies have focused on the mechanisms of spine formation, considerable progress has been made recently in delineating the neural activity patterns and downstream molecular mechanisms that drive dendritic spine elimination. Here, we review the current state of knowledge concerning the signaling pathways that drive dendritic spine shrinkage and elimination in the cerebral cortex and we discuss their implication in neuropsychiatric and neurodegenerative disease.
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Affiliation(s)
- Ivar S Stein
- 1 Center for Neuroscience, University of California, Davis, CA, USA
| | - Karen Zito
- 1 Center for Neuroscience, University of California, Davis, CA, USA
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130
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Ladislav M, Cerny J, Krusek J, Horak M, Balik A, Vyklicky L. The LILI Motif of M3-S2 Linkers Is a Component of the NMDA Receptor Channel Gate. Front Mol Neurosci 2018; 11:113. [PMID: 29681798 PMCID: PMC5897735 DOI: 10.3389/fnmol.2018.00113] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 03/22/2018] [Indexed: 11/13/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) mediate excitatory synaptic transmission in the central nervous system, underlie the induction of synaptic plasticity, and their malfunction is associated with human diseases. Native NMDARs are tetramers composed of two obligatory GluN1 subunits and various combinations of GluN2A-D or, more rarely, GluN3A-B subunits. Each subunit consists of an amino-terminal, ligand-binding, transmembrane and carboxyl-terminal domain. The ligand-binding and transmembrane domains are interconnected via polypeptide chains (linkers). Upon glutamate and glycine binding, these receptors undergo a series of conformational changes leading to the opening of the Ca2+-permeable ion channel. Here we report that different deletions and mutations of amino acids in the M3-S2 linkers of the GluN1 and GluN2B subunits lead to constitutively open channels. Irrespective of whether alterations were introduced in the GluN1 or the GluN2B subunit, application of glutamate or glycine promoted receptor channel activity; however, responses induced by the GluN1 agonist glycine were larger, on average, than those induced by glutamate. We observed the most prominent effect when residues GluN1(L657) and GluN2B(I655) were deleted or altered to glycine. In parallel, molecular modeling revealed that two interacting pairs of residues, the LILI motif (GluN1(L657) and GluN2B(I655)), form a functional unit with the TTTT ring (GluN1(T648) and GluN2B(T647)), described earlier to control NMDAR channel gating. These results provide new insight into the structural organization and functional interplay of the LILI and the TTTT ring during the course of NMDAR channel opening and closing.
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Affiliation(s)
- Marek Ladislav
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia.,Department of Physiology, Faculty of Science, Charles University in Prague, Albertov, Czechia
| | - Jiri Cerny
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Jan Krusek
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Martin Horak
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Ales Balik
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Ladislav Vyklicky
- Department of Cellular Neurophysiology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
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131
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Long-Term Depression Is Independent of GluN2 Subunit Composition. J Neurosci 2018; 38:4462-4470. [PMID: 29593052 DOI: 10.1523/jneurosci.0394-18.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/16/2018] [Accepted: 03/20/2018] [Indexed: 11/21/2022] Open
Abstract
NMDA receptors (NMDARs) mediate both long-term potentiation and long-term depression (LTD) and understanding how a single receptor can initiate both phenomena remains a major question in neuroscience. A prominent hypothesis implicates the NMDAR subunit composition, specifically GluN2A and GluN2B, in dictating the rules of synaptic plasticity. However, studies testing this hypothesis have yielded inconsistent and often contradictory results, especially for LTD. These inconsistent results may be due to challenges in the interpretation of subunit-selective pharmacology and in dissecting out the contributions of differential channel properties versus the interacting proteins unique to GluN2A or GluN2B. In this study, we address the pharmacological and biochemical challenges by using a single-neuron genetic approach to delete NMDAR subunits in conditional knock-out mice. In addition, the recently discovered non-ionotropic nature of NMDAR-dependent LTD allowed the rigorous assessment of unique subunit contributions to NMDAR-dependent LTD while eliminating the variable of differential charge transfer. Here we find that neither the GluN2A nor the GluN2B subunit is strictly necessary for either non-ionotropic or ionotropic LTD.SIGNIFICANCE STATEMENT NMDA receptors are key regulators of bidirectional synaptic plasticity. Understanding the mechanisms regulating bidirectional plasticity will guide development of therapeutic strategies to treat the dysfunctional synaptic plasticity in multiple neuropsychiatric disorders. Because of the unique properties of the NMDA receptor GluN2 subunits, they have been postulated to differentially affect synaptic plasticity. However, there has been significant controversy regarding the roles of the GluN2 subunits in synaptic long term depression (LTD). Using single-neuron knock-out of the GluN2 subunits, we show that LTD requires neither GluN2A nor GluN2B.
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132
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Abstract
A defining feature of HIV-associated neurocognitive disorder (HAND) is the loss of excitatory synaptic connections. Synaptic changes that occur during exposure to HIV appear to result, in part, from a homeostatic scaling response. Here we discuss the mechanisms of these changes from the perspective that they might be part of a coping mechanism that reduces synapses to prevent excitotoxicity. In transgenic animals expressing the HIV proteins Tat or gp120, the loss of synaptic markers precedes changes in neuronal number. In vitro studies have shown that HIV-induced synapse loss and cell death are mediated by distinct mechanisms. Both in vitro and animal studies suggest that HIV-induced synaptic scaling engages new mechanisms that suppress network connectivity and that these processes might be amenable to therapeutic intervention. Indeed, pharmacological reversal of synapse loss induced by HIV Tat restores cognitive function. In summary, studies indicate that there are temporal, mechanistic and pharmacological features of HIV-induced synapse loss that are consistent with homeostatic plasticity. The increasingly well delineated signaling mechanisms that regulate synaptic scaling may reveal pharmacological targets suitable for normalizing synaptic function in chronic neuroinflammatory states such as HAND.
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Affiliation(s)
- Matthew V Green
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Jonathan D Raybuck
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Xinwen Zhang
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Mariah M Wu
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Stanley A Thayer
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
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133
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O'Riordan KJ, Hu NW, Rowan MJ. Physiological activation of mGlu5 receptors supports the ion channel function of NMDA receptors in hippocampal LTD induction in vivo. Sci Rep 2018. [PMID: 29535352 PMCID: PMC5849730 DOI: 10.1038/s41598-018-22768-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Synaptic long-term depression (LTD) is believed to underlie critical mnemonic processes in the adult hippocampus. The roles of the metabotropic and ionotropic actions of glutamate in the induction of synaptic LTD by electrical low-frequency stimulation (LFS) in the living adult animal is poorly understood. Here we examined the requirement for metabotropic glutamate (mGlu) and NMDA receptors in LTD induction in anaesthetized adult rats. LTD induction was primarily dependent on NMDA receptors and required the involvement of both the ion channel function and GluN2B subunit of the receptor. Endogenous mGlu5 receptor activation necessitated the local application of relatively high doses of either competitive or non-competitive NMDA receptor antagonists to block LTD induction. Moreover, boosting endogenous glutamate activation of mGlu5 receptors with a positive allosteric modulator lowered the threshold for NMDA receptor-dependent LTD induction by weak LFS. The present data provide support in the living animal that NMDA receptor-dependent LTD is boosted by endogenously released glutamate activation of mGlu5 receptors. Given the predominant perisynaptic location of mGlu5 receptors, the present findings emphasize the need to further evaluate the contribution and mechanisms of these receptors in NMDA receptor-dependent synaptic plasticity in the adult hippocampus in vivo.
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Affiliation(s)
- Kenneth J O'Riordan
- Department of Pharmacology and Therapeutics and Institute of Neuroscience, Watts Building, Trinity College, Dublin, 2, Ireland
| | - Neng-Wei Hu
- Department of Pharmacology and Therapeutics and Institute of Neuroscience, Watts Building, Trinity College, Dublin, 2, Ireland. .,Department of Gerontology, Yijishan Hospital, Wannan Medical College, Wuhu, China. .,Department of Physiology and Neurobiology, Zhengzhou University School of Medicine, Zhengzhou, 450001, China.
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics and Institute of Neuroscience, Watts Building, Trinity College, Dublin, 2, Ireland.
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134
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Sason H, Billard JM, Smith GP, Safory H, Neame S, Kaplan E, Rosenberg D, Zubedat S, Foltyn VN, Christoffersen CT, Bundgaard C, Thomsen C, Avital A, Christensen KV, Wolosker H. Asc-1 Transporter Regulation of Synaptic Activity via the Tonic Release of d-Serine in the Forebrain. Cereb Cortex 2018; 27:1573-1587. [PMID: 26796213 DOI: 10.1093/cercor/bhv350] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
d-Serine is a co-agonist of NMDA receptors (NMDARs) whose activity is potentially regulated by Asc-1 (SLC7A10), a transporter that displays high affinity for d-serine and glycine. Asc-1 operates as a facilitative transporter and as an antiporter, though the preferred direction of d-serine transport is uncertain. We developed a selective Asc-1 blocker, Lu AE00527, that blocks d-serine release mediated by all the transport modes of Asc-1 in primary cultures and neocortical slices. Furthermore, d-serine release is reduced in slices from Asc-1 knockout (KO) mice, indicating that d-serine efflux is the preferred direction of Asc-1. The selectivity of Lu AE00527 is assured by the lack of effect on slices from Asc-1-KO mice, and the lack of interaction with the co-agonist site of NMDARs. Moreover, in vivo injection of Lu AE00527 in P-glycoprotein-deficient mice recapitulates a hyperekplexia-like phenotype similar to that in Asc-1-KO mice. In slices, Lu AE00527 decreases the long-term potentiation at the Schaffer collateral-CA1 synapses, but does not affect the long-term depression. Lu AE00527 blocks NMDAR synaptic potentials when typical Asc-1 extracellular substrates are present, but it does not affect AMPAR transmission. Our data demonstrate that Asc-1 mediates tonic co-agonist release, which is required for optimal NMDAR activation and synaptic plasticity.
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Affiliation(s)
- Hagit Sason
- Department of Biochemistry, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Jean Marie Billard
- UMR894, Centre de Psychiatrie et Neurosciences, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | | | - Hazem Safory
- Department of Biochemistry, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Samah Neame
- Department of Biochemistry, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Eitan Kaplan
- Department of Biochemistry, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Dina Rosenberg
- Department of Biochemistry, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Salman Zubedat
- Department of Biochemistry, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Veronika N Foltyn
- Department of Biochemistry, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | | | | | - Christian Thomsen
- Drug Discovery Neuroscience, H. Lundbeck A/S, DK-2500 Valby, Denmark
| | - Avi Avital
- Department of Biochemistry, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 31096, Israel.,Emek Medical Center, Afula, Israel
| | | | - Herman Wolosker
- Department of Biochemistry, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 31096, Israel
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135
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Krania P, Dimou E, Bantouna M, Kouvaros S, Tsiamaki E, Papatheodoropoulos C, Sarantis K, Angelatou F. Adenosine A 2A receptors are required for glutamate mGluR5- and dopamine D1 receptor-evoked ERK1/2 phosphorylation in rat hippocampus: involvement of NMDA receptor. J Neurochem 2018; 145:217-231. [PMID: 29205377 DOI: 10.1111/jnc.14268] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/11/2017] [Accepted: 11/24/2017] [Indexed: 12/17/2022]
Abstract
Interaction between mGluR5 and NMDA receptors (NMDAR) is vital for synaptic plasticity and cognition. We recently demonstrated that stimulation of mGluR5 enhances NMDAR responses in hippocampus by phosphorylating NR2B(Tyr1472) subunit, and this reaction was enabled by adenosine A2A receptors (A2A R) (J Neurochem, 135, 2015, 714). In this study, by using in vitro phosphorylation and western blot analysis in hippocampal slices of male Wistar rats, we show that mGluR5 stimulation or mGluR5/NMDARs co-stimulation synergistically activate ERK1/2 signaling leading to c-Fos expression. Interestingly, both reactions are under the permissive control of endogenous adenosine acting through A2A Rs. Moreover, mGluR5-mediated ERK1/2 phosphorylation depends on NMDAR, which however exhibits a metabotropic way of function, since no ion influx through its ion channel is required. Furthermore, our results demonstrate that mGluR5 and mGluR5/NMDAR-evoked ERK1/2 activation correlates well with the mGluR5/NMDAR-evoked NR2B(Tyr1472) phosphorylation, since both phenomena coincide temporally, are Src dependent, and are both enabled by A2A Rs. This indicates a functional involvement of NR2B(Tyr1472) phosphorylation in the ERK1/2 activation. Our biochemical results are supported by electrophysiological data showing that in CA1 region of hippocampus, the theta burst stimulation (TBS)-induced long-term potentiation coincides temporally with an increase in ERK1/2 activation and both phenomena are dependent on the tripartite A2A , mGlu5, and NMDARs. Furthermore, we show that the dopamine D1 receptors evoked ERK1/2 activation as well as the NR2B(Tyr1472) phosphorylation are also regulated by endogenous adenosine and A2A Rs. In conclusion, our results highlight the A2A Rs as a crucial regulator not only for NMDAR responses, but also for regulating ERK1/2 signaling and its downstream pathways, leading to gene expression, synaptic plasticity, and memory consolidation.
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Affiliation(s)
- Paraskevi Krania
- Physiology Department, Medical School, University of Patras, Patras, Greece
| | - Eleni Dimou
- Physiology Department, Medical School, University of Patras, Patras, Greece
| | - Maria Bantouna
- Physiology Department, Medical School, University of Patras, Patras, Greece
| | - Stylianos Kouvaros
- Physiology Department, Medical School, University of Patras, Patras, Greece
| | - Eirini Tsiamaki
- Physiology Department, Medical School, University of Patras, Patras, Greece
| | | | | | - Fevronia Angelatou
- Physiology Department, Medical School, University of Patras, Patras, Greece
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136
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Galliano E, Schonewille M, Peter S, Rutteman M, Houtman S, Jaarsma D, Hoebeek FE, De Zeeuw CI. Impact of NMDA Receptor Overexpression on Cerebellar Purkinje Cell Activity and Motor Learning. eNeuro 2018; 5:ENEURO.0270-17.2018. [PMID: 29464191 PMCID: PMC5815660 DOI: 10.1523/eneuro.0270-17.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 12/24/2017] [Accepted: 01/23/2018] [Indexed: 11/21/2022] Open
Abstract
In many brain regions involved in learning NMDA receptors (NMDARs) act as coincidence detectors of pre- and postsynaptic activity, mediating Hebbian plasticity. Intriguingly, the parallel fiber (PF) to Purkinje cell (PC) input in the cerebellar cortex, which is critical for procedural learning, shows virtually no postsynaptic NMDARs. Why is this? Here, we address this question by generating and testing independent transgenic lines that overexpress NMDAR containing the type 2B subunit (NR2B) specifically in PCs. PCs of the mice that show larger NMDA-mediated currents than controls at their PF input suffer from a blockage of long-term potentiation (LTP) at their PF-PC synapses, while long-term depression (LTD) and baseline transmission are unaffected. Moreover, introducing NMDA-mediated currents affects cerebellar learning in that phase-reversal of the vestibulo-ocular reflex (VOR) is impaired. Our results suggest that under physiological circumstances PC spines lack NMDARs postsynaptically at their PF input so as to allow LTP to contribute to motor learning.
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Affiliation(s)
- Elisa Galliano
- Department of Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Martijn Schonewille
- Department of Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Saša Peter
- Department of Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Mandy Rutteman
- Department of Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Simone Houtman
- Department of Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Dick Jaarsma
- Department of Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Freek E. Hoebeek
- Department of Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Chris I. De Zeeuw
- Department of Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
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137
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Unconventional NMDA Receptor Signaling. J Neurosci 2017; 37:10800-10807. [PMID: 29118208 DOI: 10.1523/jneurosci.1825-17.2017] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/28/2017] [Accepted: 09/28/2017] [Indexed: 11/21/2022] Open
Abstract
In the classical view, NMDA receptors (NMDARs) are stably expressed at the postsynaptic membrane, where they act via Ca2+ to signal coincidence detection in Hebbian plasticity. More recently, it has been established that NMDAR-mediated transmission can be dynamically regulated by neural activity. In addition, NMDARs have been found presynaptically, where they cannot act as conventional coincidence detectors. Unexpectedly, NMDARs have also been shown to signal metabotropically, without the need for Ca2+ This review highlights novel findings concerning these unconventional modes of NMDAR action.
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138
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Babiec WE, O'Dell TJ. Novel Ca 2+-dependent mechanisms regulate spontaneous release at excitatory synapses onto CA1 pyramidal cells. J Neurophysiol 2017; 119:597-607. [PMID: 29142096 DOI: 10.1152/jn.00628.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Although long thought to simply be a source of synaptic noise, spontaneous, action potential-independent release of neurotransmitter from presynaptic terminals has multiple roles in synaptic function. We explored whether and to what extent the two predominantly proposed mechanisms for explaining spontaneous release, stochastic activation of voltage-gated Ca2+ channels (VGCCs) or activation of Ca2+-sensing receptors (CaSRs) by extracellular Ca2+, played a role in the sensitivity of spontaneous release to the level of extracellular Ca2+ concentration at excitatory synapses at CA1 pyramidal cells of the adult male mouse hippocampus. Blocking VGCCs with Cd2+ had no effect on spontaneous release, ruling out stochastic activation of VGCCs. Although divalent cation agonists of CaSRs, Co2+ and Mg2+, dramatically enhanced miniature excitatory postsynaptic current (mEPSC) frequency, potent positive and negative allosteric modulators of CaSRs had no effect. Moreover, immunoblot analysis of hippocampal lysates failed to detect CaSR expression, ruling out the CaSR. Instead, the increase in mEPSC frequency induced by Co2+ and Mg2+ was mimicked by lowering postsynaptic Ca2+ levels with BAPTA. Together, our results suggest that a reduction in intracellular Ca2+ may trigger a homeostatic-like compensatory response that upregulates spontaneous transmission at excitatory synapses onto CA1 pyramidal cells in the adult hippocampus. NEW & NOTEWORTHY We show that the predominant theories for explaining the regulation of spontaneous, action potential-independent synaptic release do not explain the sensitivity of this type of synaptic transmission to external Ca2+ concentration at excitatory synapses onto hippocampal CA1 pyramidal cells. In addition, our data indicate that intracellular Ca2+ levels in CA1 pyramidal cells regulate spontaneous release, suggesting that excitatory synapses onto CA1 pyramidal cells may express a novel, rapid form of homeostatic plasticity.
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Affiliation(s)
- Walter E Babiec
- Department of Physiology, David Geffen School of Medicine at UCLA , Los Angeles, California
| | - Thomas J O'Dell
- Department of Physiology, David Geffen School of Medicine at UCLA , Los Angeles, California.,UCLA Integrative Center for Learning and Memory, Brain Research Institute, UCLA, Los Angeles, California
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139
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Padamsey Z, Tong R, Emptage N. Glutamate is required for depression but not potentiation of long-term presynaptic function. eLife 2017; 6:29688. [PMID: 29140248 PMCID: PMC5714480 DOI: 10.7554/elife.29688] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 11/14/2017] [Indexed: 12/20/2022] Open
Abstract
Hebbian plasticity is thought to require glutamate signalling. We show this is not the case for hippocampal presynaptic long-term potentiation (LTPpre), which is expressed as an increase in transmitter release probability (Pr). We find that LTPpre can be induced by pairing pre- and postsynaptic spiking in the absence of glutamate signalling. LTPpre induction involves a non-canonical mechanism of retrograde nitric oxide signalling, which is triggered by Ca2+ influx from L-type voltage-gated Ca2+ channels, not postsynaptic NMDA receptors (NMDARs), and does not require glutamate release. When glutamate release occurs, it decreases Pr by activating presynaptic NMDARs, and promotes presynaptic long-term depression. Net changes in Pr, therefore, depend on two opposing factors: (1) Hebbian activity, which increases Pr, and (2) glutamate release, which decreases Pr. Accordingly, release failures during Hebbian activity promote LTPpre induction. Our findings reveal a novel framework of presynaptic plasticity that radically differs from traditional models of postsynaptic plasticity. Neurons communicate with one another at junctions called synapses. One neuron at the synapse releases a chemical substance called a neurotransmitter, which binds to and activates the other neuron. The release of neurotransmitter thus enables the electrical activity of one cell to influence the electrical activity of another. The efficiency of this communication can change over time, as is thought to occur during learning. If the neurons on both sides of a synapse are repeatedly active at the same time, the ability of the neurons to transmit electrical signals to each other increases. One way that communication between neurons can become more efficient is if the first neuron becomes more likely to release neurotransmitter. Most synapses in the brain release a neurotransmitter called glutamate, and most types of learning involve changes in the efficiency of communication at glutamatergic synapses. But glutamate release is unreliable. Active glutamatergic neurons fail to release glutamate about 80% of the time. If glutamate has a key role in learning, how does the brain learn efficiently when glutamate release is so unlikely? To find out, Padamsey et al. studied glutamatergic synapses in slices of tissue from mouse and rat brains. When both neurons at a synapse were repeatedly active at the same time, the first neuron would sometimes become more likely to release glutamate. But this only happened at synapses in which the first neuron usually failed to release glutamate in the first place. This suggests that communication failures help to drive change at synapses. When two neurons that are often active at the same time do not communicate efficiently, this failure triggers molecular changes that make future communication more reliable. Previous results have shown that synapses can change when glutamate release occurs. The current results show that they can also change when it does not. This means that the brain can continue to learn despite frequent communication failures between neurons. Many neurological disorders, including Alzheimer’s disease, show altered glutamate signalling at synapses. Padamsey et al. hope that a better understanding of this process will lead to new therapies for these disorders.
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Affiliation(s)
- Zahid Padamsey
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom.,Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Rudi Tong
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Nigel Emptage
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
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140
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Differential Regulation of Evoked and Spontaneous Release by Presynaptic NMDA Receptors. Neuron 2017; 96:839-855.e5. [DOI: 10.1016/j.neuron.2017.09.030] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/03/2017] [Accepted: 09/19/2017] [Indexed: 01/04/2023]
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141
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Ding S, Wang X, Zhuge W, Yang J, Zhuge Q. Dopamine induces glutamate accumulation in astrocytes to disrupt neuronal function leading to pathogenesis of minimal hepatic encephalopathy. Neuroscience 2017; 365:94-113. [PMID: 28965835 DOI: 10.1016/j.neuroscience.2017.09.040] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 09/20/2017] [Accepted: 09/23/2017] [Indexed: 12/15/2022]
Abstract
Minimal hepatic encephalopathy (MHE) is induced by elevated intracranial dopamine (DA). Glutamate (Glu) toxicity is known to be involved in many neurological disorders. In this study, we investigated whether DA increased Glu levels and collaborated with Glu to impair memory. We found that DA upregulated TAAR1, leading to reduced EAAT2 expression and Glu clearance in primary cortical astrocytes (PCAs). High DA increased TAAR1 expression, and high Glu increased AMPAR expression, inducing the activation of CaN/NFAT signaling and a decrease in the production of BDNF (Brain Derived Nerve Growth Factor)/NT3 (neurotrophin-3) in primary cortical neurons (PCNs). DA activated TAAR1 to downregulate EAAT2 and increase extracellular Glu levels in MHE. Additionally, DA together with Glu caused decreased production of neuronal BDNF/NT3 and memory impairment through the activation of CaN/NFAT signaling in MHE. From these findings, we conclude that DA increases Glu levels via interaction with TAAR1 and disruption of EAAT2 signaling in astrocytes, and DA interacting with TAAR1 and Glu interacting with AMPAR synergistically decreased the production of BDNF by activation of CaN/NFAT signaling to impair memory in MHE rats.
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Affiliation(s)
- Saidan Ding
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, Department of Surgery Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China
| | - Xuebao Wang
- Analytical and Testing Center, Wenzhou Medical University, Wenzhou, Zhejiang 325000, China
| | - Weishan Zhuge
- Gastrointestinal Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China
| | - Jianjing Yang
- Neurosurgery Department, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China
| | - Qichuan Zhuge
- Neurosurgery Department, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China.
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142
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Valbuena S, Lerma J. Non-canonical Signaling, the Hidden Life of Ligand-Gated Ion Channels. Neuron 2017; 92:316-329. [PMID: 27764665 DOI: 10.1016/j.neuron.2016.10.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/03/2016] [Accepted: 10/06/2016] [Indexed: 12/25/2022]
Abstract
Neurotransmitter receptors are responsible for the transfer of information across the synapse. While ionotropic receptors form ion channels and mediate rapid membrane depolarization, so-called metabotropic receptors exert their action though slower, less direct intracellular signaling pathways. Glutamate, GABA, and acetylcholine can activate both ionotropic and metabotropic receptors, yet the distinction between these "canonical" signaling systems has become less clear since ionotropic receptors were proposed to also activate second messenger systems, defining a "non-canonical" signaling pathway. How these alternative pathways affect neuronal circuit activity is not well understood, and their influence could be more significant than previously anticipated. In this review, we examine the evidence available that supports the existence of parallel and unsuspected signaling pathways used by ionotropic neurotransmitter receptors.
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Affiliation(s)
- Sergio Valbuena
- Instituto de Neurociencias CSIC-UMH, 03550 San Juan de Alicante, Spain
| | - Juan Lerma
- Instituto de Neurociencias CSIC-UMH, 03550 San Juan de Alicante, Spain.
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143
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Sun MY, Chisari M, Eisenman LN, Zorumski CF, Mennerick SJ. Contributions of space-clamp errors to apparent time-dependent loss of Mg 2+ block induced by NMDA. J Neurophysiol 2017; 118:532-543. [PMID: 28356471 DOI: 10.1152/jn.00106.2017] [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: 02/15/2017] [Revised: 03/17/2017] [Accepted: 03/27/2017] [Indexed: 11/22/2022] Open
Abstract
N-methyl-d-aspartate receptors (NMDARs) govern synaptic plasticity, development, and neuronal response to insult. Prolonged activation of NMDARs such as during an insult may activate secondary currents or modulate Mg2+ sensitivity, but the conditions under which these occur are not fully defined. We reexamined the effect of prolonged NMDAR activation in juvenile mouse hippocampal slices. NMDA (10 μM) elicited current with the expected negative-slope conductance in the presence of 1.2 mM Mg2+ However, several minutes of continued NMDA exposure elicited additional inward current at -70 mV. A higher concentration of NMDA (100 µM) elicited the current more rapidly. The additional current was not dependent on Ca2+, network activity, or metabotropic NMDAR function and did not persist on agonist removal. Voltage ramps revealed no alteration of either reversal potential or NMDA-elicited conductance between -30 mV and +50 mV. The result was a more linear NMDA current-voltage relationship. The current linearization was also induced in interneurons and in mature dentate granule neurons but not immature dentate granule cells, dissociated cultured hippocampal neurons, or nucleated patches excised from CA1 pyramidal neurons. Comparative simulations of NMDA application to a CA1 pyramidal neuron and to a cultured neuron revealed that linearization can be explained by space-clamp errors arising from gradual recruitment of distal dendritic NMDARs. We conclude that persistent secondary currents do not strongly contribute to NMDAR responses in juvenile mouse hippocampus and careful discernment is needed to exclude contributions of clamp artifacts to apparent secondary currents.NEW & NOTEWORTHY We report that upon sustained activation of NMDARs in juvenile mouse hippocampal neurons there is apparent loss of Mg2+ block at negative membrane potentials. However, the phenomenon is explained by loss of dendritic voltage clamp, leading to a linear current-voltage relationship. Our results give a specific example of how spatial voltage errors in voltage-clamp recordings can readily be misinterpreted as biological modulation.
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Affiliation(s)
- Min-Yu Sun
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri
| | - Mariangela Chisari
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, University of Catania, Catania, Italy
| | - Lawrence N Eisenman
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri
| | - Charles F Zorumski
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri.,Department of Neuroscience, Washington University School of Medicine, St. Louis, Missouri.,Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri.,Center for Brain Research in Mood Disorders, Washington University School of Medicine, St. Louis, Missouri; and
| | - Steven J Mennerick
- Department of Psychiatry, Washington University School of Medicine, St. Louis, Missouri; .,Department of Neuroscience, Washington University School of Medicine, St. Louis, Missouri.,Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri
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144
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Chen J, Hu R, Liao H, Zhang Y, Lei R, Zhang Z, Zhuang Y, Wan Y, Jin P, Feng H, Wan Q. A non-ionotropic activity of NMDA receptors contributes to glycine-induced neuroprotection in cerebral ischemia-reperfusion injury. Sci Rep 2017; 7:3575. [PMID: 28620235 PMCID: PMC5472592 DOI: 10.1038/s41598-017-03909-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 05/05/2017] [Indexed: 01/01/2023] Open
Abstract
NMDA receptor (NMDAR) is known for its ionotropic function. But recent evidence suggests that NMDAR also has a non-ionotropic property. To determine the role of non-ionotropic activity of NMDARs in clinical relevant conditions, we tested the effect of glycine, a co-agonist of NMDARs, in rat middle cerebral artery occlusion (MCAO), an animal model of cerebral ischemia-reperfusion injury after the animals were injected with the NMDAR channel blocker MK-801 and the glycine receptor antagonist strychnine. We show that glycine reduces the infarct volume in the brain of ischemic stroke animals pre-injected with MK-801 and strychnine. The effect of glycine is sensitive to the antagonist of glycine-GluN1 binding site and blocked by Akt inhibition. In the neurobehavioral tests, glycine improves the functional recovery of stroke animals pre-injected with MK-801 and strychnine. This study suggests that glycine-induced neuroprotection is mediated in part by the non-ionotropic activity of NMDARs via Akt activation in cerebral ischemia-reperfusion injury.
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Affiliation(s)
- Juan Chen
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, School of Medicine, Wuhan University, 185 Donghu Street, Wuhan, Hubei, 430071, China. .,Department of Neurology, the Central Hospital of Wuhan, Tongji Medical College of Huazhong University of Science & Technology, 26 Shengli Street, Wuhan, 430014, China.
| | - Rong Hu
- Department of Neurosurgery, Southwest Hospital, Chongqing, 400038, China
| | - Huabao Liao
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, School of Medicine, Wuhan University, 185 Donghu Street, Wuhan, Hubei, 430071, China
| | - Ya Zhang
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, School of Medicine, Wuhan University, 185 Donghu Street, Wuhan, Hubei, 430071, China
| | - Ruixue Lei
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, School of Medicine, Wuhan University, 185 Donghu Street, Wuhan, Hubei, 430071, China
| | - Zhifeng Zhang
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, School of Medicine, Wuhan University, 185 Donghu Street, Wuhan, Hubei, 430071, China
| | - Yang Zhuang
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, School of Medicine, Wuhan University, 185 Donghu Street, Wuhan, Hubei, 430071, China
| | - Yu Wan
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, School of Medicine, Wuhan University, 185 Donghu Street, Wuhan, Hubei, 430071, China
| | - Ping Jin
- Department of Neurology, the Central Hospital of Wuhan, Tongji Medical College of Huazhong University of Science & Technology, 26 Shengli Street, Wuhan, 430014, China
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital, Chongqing, 400038, China
| | - Qi Wan
- Department of Physiology, Collaborative Innovation Center for Brain Science, School of Basic Medical Sciences, School of Medicine, Wuhan University, 185 Donghu Street, Wuhan, Hubei, 430071, China. .,Institute of Neuroregeneration & Neurorehabilitation, Qingdao University School of Medicine, 308 Ningxia Street, Qingdao, 266071, China.
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145
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Ferreira JS, Papouin T, Ladépêche L, Yao A, Langlais VC, Bouchet D, Dulong J, Mothet JP, Sacchi S, Pollegioni L, Paoletti P, Oliet SHR, Groc L. Co-agonists differentially tune GluN2B-NMDA receptor trafficking at hippocampal synapses. eLife 2017; 6. [PMID: 28598327 PMCID: PMC5466419 DOI: 10.7554/elife.25492] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 05/29/2017] [Indexed: 12/28/2022] Open
Abstract
The subunit composition of synaptic NMDA receptors (NMDAR), such as the relative content of GluN2A- and GluN2B-containing receptors, greatly influences the glutamate synaptic transmission. Receptor co-agonists, glycine and D-serine, have intriguingly emerged as potential regulators of the receptor trafficking in addition to their requirement for its activation. Using a combination of single-molecule imaging, biochemistry and electrophysiology, we show that glycine and D-serine relative availability at rat hippocampal glutamatergic synapses regulate the trafficking and synaptic content of NMDAR subtypes. Acute manipulations of co-agonist levels, both ex vivo and in vitro, unveil that D-serine alter the membrane dynamics and content of GluN2B-NMDAR, but not GluN2A-NMDAR, at synapses through a process requiring PDZ binding scaffold partners. In addition, using FRET-based FLIM approach, we demonstrate that D-serine rapidly induces a conformational change of the GluN1 subunit intracellular C-terminus domain. Together our data fuels the view that the extracellular microenvironment regulates synaptic NMDAR signaling.
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Affiliation(s)
- Joana S Ferreira
- Interdisciplinary Institute for NeuroSciences, CNRS UMR 5297, Bordeaux, France.,Université de Bordeaux, Bordeaux, France
| | - Thomas Papouin
- Université de Bordeaux, Bordeaux, France.,NSERM U862, Neurocentre Magendie, Bordeaux, France
| | - Laurent Ladépêche
- Interdisciplinary Institute for NeuroSciences, CNRS UMR 5297, Bordeaux, France.,Université de Bordeaux, Bordeaux, France
| | - Andrea Yao
- Institut de Biologie de l'ENS (IBENS), CNRS UMR 8197, INSERM U1024, Paris, France
| | - Valentin C Langlais
- Université de Bordeaux, Bordeaux, France.,NSERM U862, Neurocentre Magendie, Bordeaux, France
| | - Delphine Bouchet
- Interdisciplinary Institute for NeuroSciences, CNRS UMR 5297, Bordeaux, France.,Université de Bordeaux, Bordeaux, France
| | - Jérôme Dulong
- Université de Bordeaux, Bordeaux, France.,NSERM U862, Neurocentre Magendie, Bordeaux, France
| | | | - Silvia Sacchi
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy.,The Protein Factory, Centro Interuniversitario di Biotecnologie Proteiche, Politecnico di Milano, Università degli Studi dell'Insubria, Varese, Italy
| | - Loredano Pollegioni
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Varese, Italy.,The Protein Factory, Centro Interuniversitario di Biotecnologie Proteiche, Politecnico di Milano, Università degli Studi dell'Insubria, Varese, Italy
| | - Pierre Paoletti
- Institut de Biologie de l'ENS (IBENS), CNRS UMR 8197, INSERM U1024, Paris, France
| | | | - Laurent Groc
- Interdisciplinary Institute for NeuroSciences, CNRS UMR 5297, Bordeaux, France
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146
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Yuzaki M, Aricescu AR. A GluD Coming-Of-Age Story. Trends Neurosci 2017; 40:138-150. [PMID: 28110935 DOI: 10.1016/j.tins.2016.12.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 12/19/2016] [Accepted: 12/22/2016] [Indexed: 01/02/2023]
Abstract
The GluD1 and GluD2 receptors form the GluD ionotropic glutamate receptor (iGluR) subfamily. Without known endogenous ligands, they have long been referred to as 'orphan' and remained enigmatic functionally. Recent progress has, however, radically changed this view. Both GluD receptors are expressed in wider brain regions than originally thought. Human genetic studies and analyses of knockout mice have revealed their involvement in multiple neurodevelopmental and psychiatric disorders. The discovery of endogenous ligands, together with structural investigations, has opened the way towards a mechanistic understanding of GluD signaling at central nervous system synapses. These studies have also prompted the hypothesis that all iGluRs, and potentially other neurotransmitter receptors, rely on the cooperative binding of extracellular small-molecule and protein ligands for physiological signaling.
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Affiliation(s)
- Michisuke Yuzaki
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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147
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Winnubst J, Lohmann C. Mapping Synaptic Inputs of Developing Neurons Using Calcium Imaging. Methods Mol Biol 2017; 1538:341-352. [PMID: 27943200 DOI: 10.1007/978-1-4939-6688-2_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Studying changing synaptic activity patterns during development provides a wealth of information on how activity-dependent processes shape synaptic connectivity. In this chapter we introduce a method that combines whole-cell electrophysiology with calcium imaging to map functional synaptic sites on the dendritic tree and follow their activity over time. The key strength of this method lies in its ability to distinguish between synaptic and non-synaptic calcium signaling by their coincidence with synaptic currents measured at the soma. Next to the required materials and protocols that are necessary to perform these experiments, we thoroughly discuss how the acquired data can be analyzed. Since this method can be employed in many neuronal systems we believe that it can be a valuable tool to study developmental changes in synaptic connectivity.
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Affiliation(s)
- Johan Winnubst
- Department of Synapse and Network Development, Netherlands Institute for Neuroscience, Meibergdreef 47, Amsterdam, BA, 1105, The Netherlands
- Janelia Research Campus, Howard Hughes Medical Institute, 19700 Helix Drive, Ashburn, VA, 20147, USA
| | - Christian Lohmann
- Department of Synapse and Network Development, Netherlands Institute for Neuroscience, Meibergdreef 47, Amsterdam, BA, 1105, The Netherlands.
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148
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Hansen KB, Yi F, Perszyk RE, Menniti FS, Traynelis SF. NMDA Receptors in the Central Nervous System. Methods Mol Biol 2017; 1677:1-80. [PMID: 28986865 DOI: 10.1007/978-1-4939-7321-7_1] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
NMDA-type glutamate receptors are ligand-gated ion channels that mediate a major component of excitatory neurotransmission in the central nervous system (CNS). They are widely distributed at all stages of development and are critically involved in normal brain functions, including neuronal development and synaptic plasticity. NMDA receptors are also implicated in the pathophysiology of numerous neurological and psychiatric disorders, such as ischemic stroke, traumatic brain injury, Alzheimer's disease, epilepsy, mood disorders, and schizophrenia. For these reasons, NMDA receptors have been intensively studied in the past several decades to elucidate their physiological roles and to advance them as therapeutic targets. Seven NMDA receptor subunits exist that assemble into a diverse array of tetrameric receptor complexes, which are differently regulated, have distinct regional and developmental expression, and possess a wide range of functional and pharmacological properties. The diversity in subunit composition creates NMDA receptor subtypes with distinct physiological roles across neuronal cell types and brain regions, and enables precise tuning of synaptic transmission. Here, we will review the relationship between NMDA receptor structure and function, the diversity and significance of NMDA receptor subtypes in the CNS, as well as principles and rules by which NMDA receptors operate in the CNS under normal and pathological conditions.
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Affiliation(s)
- Kasper B Hansen
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, USA. .,Center for Biomolecular Structure and Dynamics, University of Montana, Missoula, MT, USA.
| | - Feng Yi
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, MT, USA
| | - Riley E Perszyk
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Frank S Menniti
- MindImmune Therapeutics, Inc., George & Anne Ryan Institute for Neuroscience, Kingston, RI, USA
| | - Stephen F Traynelis
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
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149
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Li LJ, Hu R, Lujan B, Chen J, Zhang JJ, Nakano Y, Cui TY, Liao MX, Chen JC, Man HY, Feng H, Wan Q. Glycine Potentiates AMPA Receptor Function through Metabotropic Activation of GluN2A-Containing NMDA Receptors. Front Mol Neurosci 2016; 9:102. [PMID: 27807405 PMCID: PMC5069295 DOI: 10.3389/fnmol.2016.00102] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 09/29/2016] [Indexed: 11/13/2022] Open
Abstract
NMDA receptors are Ca2+-permeable ion channels. The activation of NMDA receptors requires agonist glutamate and co-agonist glycine. Recent evidence indicates that NMDA receptor also has metabotropic function. Here we report that in cultured mouse hippocampal neurons, glycine increases AMPA receptor-mediated currents independent of the channel activity of NMDA receptors and the activation of glycine receptors. The potentiation of AMPA receptor function by glycine is antagonized by the inhibition of ERK1/2. In the hippocampal neurons and in the HEK293 cells transfected with different combinations of NMDA receptors, glycine preferentially acts on GluN2A-containing NMDA receptors (GluN2ARs), but not GluN2B-containing NMDA receptors (GluN2BRs), to enhance ERK1/2 phosphorylation independent of the channel activity of GluN2ARs. Without requiring the channel activity of GluN2ARs, glycine increases AMPA receptor-mediated currents through GluN2ARs. Thus, these results reveal a metabotropic function of GluN2ARs in mediating glycine-induced potentiation of AMPA receptor function via ERK1/2 activation.
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Affiliation(s)
- Li-Jun Li
- Department of Physiology, Toronto Western Research Institute, School of Medicine, University of Toronto Toronto, Canada
| | - Rong Hu
- Department of Physiology and Cell Biology, University of Nevada School of MedicineReno, NV, USA; Department of Neurosurgery, Southwest HospitalChongqing, China
| | - Brendan Lujan
- Department of Physiology and Cell Biology, University of Nevada School of Medicine Reno, NV, USA
| | - Juan Chen
- Department of Neurology, Central Hospital of Wuhan Wuhan, China
| | - Jian-Jian Zhang
- Department of Neurosurgery, Zhongnan Hospital, Wuhan University School of Medicine Wuhan, China
| | - Yasuko Nakano
- Department of Physiology and Cell Biology, University of Nevada School of Medicine Reno, NV, USA
| | - Tian-Yuan Cui
- Department of Physiology and Cell Biology, University of Nevada School of Medicine Reno, NV, USA
| | - Ming-Xia Liao
- Department of Physiology and Cell Biology, University of Nevada School of Medicine Reno, NV, USA
| | - Jin-Cao Chen
- Department of Neurosurgery, Zhongnan Hospital, Wuhan University School of Medicine Wuhan, China
| | - Heng-Ye Man
- Department of Biology, Boston University Boston, MA, USA
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital Chongqing, China
| | - Qi Wan
- Department of Physiology, Toronto Western Research Institute, School of Medicine, University of TorontoToronto, Canada; Department of Physiology and Cell Biology, University of Nevada School of MedicineReno, NV, USA; Department of Neurosurgery, Zhongnan Hospital, Wuhan University School of MedicineWuhan, China; Department of Physiology, School of Basic Medical Sciences, Wuhan University School of MedicineWuhan, China
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150
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Kronberg G, Bridi M, Abel T, Bikson M, Parra LC. Direct Current Stimulation Modulates LTP and LTD: Activity Dependence and Dendritic Effects. Brain Stimul 2016; 10:51-58. [PMID: 28104085 DOI: 10.1016/j.brs.2016.10.001] [Citation(s) in RCA: 212] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/15/2016] [Accepted: 10/03/2016] [Indexed: 10/20/2022] Open
Abstract
BACKGROUND Transcranial direct current stimulation (tDCS) has been reported to improve various forms of learning in humans. Stimulation is often applied during training, producing lasting enhancements that are specific to the learned task. These learning effects are thought to be mediated by altered synaptic plasticity. However, the effects of DCS during the induction of endogenous synaptic plasticity remain largely unexplored. OBJECTIVE/HYPOTHESIS Here we are interested in the effects of DCS applied during synaptic plasticity induction. METHODS To model endogenous plasticity we induced long-term potentiation (LTP) and depression (LTD) at Schaffer collateral synapses in CA1 of rat hippocampal slices. Anodal and cathodal DCS at 20 V/m were applied throughout plasticity induction in both apical and basal dendritic compartments. RESULTS When DCS was paired with concurrent plasticity induction, the resulting plasticity was biased towards potentiation, such that LTP was enhanced and LTD was reduced. Remarkably, both anodal and cathodal stimulation can produce this bias, depending on the dendritic location and type of plasticity induction. Cathodal DCS enhanced LTP in apical dendrites while anodal DCS enhanced LTP in basal dendrites. Both anodal and cathodal DCS reduced LTD in apical dendrites. DCS did not affect synapses that were weakly active or when NMDA receptors were blocked. CONCLUSIONS These results highlight the role of DCS as a modulator, rather than inducer of synaptic plasticity, as well as the dependence of DCS effects on the spatial and temporal properties of endogenous synaptic activity. The relevance of the present results to human tDCS should be validated in future studies.
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Affiliation(s)
- Greg Kronberg
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, USA.
| | - Morgan Bridi
- Laboratory of Neural Circuits and Behavior, Hussman Institute for Autism, Baltimore, MD 21201, USA
| | - Ted Abel
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, USA
| | - Lucas C Parra
- Department of Biomedical Engineering, The City College of New York, New York, NY 10031, USA
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