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Bär J, Fanutza T, Reimann CC, Seipold L, Grohe M, Bolter JR, Delfs F, Bucher M, Gee CE, Schweizer M, Saftig P, Mikhaylova M. Non-canonical function of ADAM10 in presynaptic plasticity. Cell Mol Life Sci 2024; 81:342. [PMID: 39123091 PMCID: PMC11335265 DOI: 10.1007/s00018-024-05327-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 06/07/2024] [Accepted: 06/17/2024] [Indexed: 08/12/2024]
Abstract
A Disintegrin And Metalloproteinase 10 (ADAM10) plays a pivotal role in shaping neuronal networks by orchestrating the activity of numerous membrane proteins through the shedding of their extracellular domains. Despite its significance in the brain, the specific cellular localization of ADAM10 remains not well understood due to a lack of appropriate tools. Here, using a specific ADAM10 antibody suitable for immunostainings, we observed that ADAM10 is localized to presynapses and especially enriched at presynaptic vesicles of mossy fiber (MF)-CA3 synapses in the hippocampus. These synapses undergo pronounced frequency facilitation of neurotransmitter release, a process that play critical roles in information transfer and neural computation. We demonstrate, that in conditional ADAM10 knockout mice the ability of MF synapses to undergo this type of synaptic plasticity is greatly reduced. The loss of facilitation depends on the cytosolic domain of ADAM10 and association with the calcium sensor synaptotagmin 7 rather than ADAM10's proteolytic activity. Our findings unveil a new role of ADAM10 in the regulation of synaptic vesicle exocytosis.
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Affiliation(s)
- Julia Bär
- AG Optobiology, Institute of Biology, Humboldt Universität Zu Berlin, 10115, Berlin, Germany
- Guest Group, "Neuronal Protein Transport", Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Tomas Fanutza
- AG Optobiology, Institute of Biology, Humboldt Universität Zu Berlin, 10115, Berlin, Germany
- Guest Group, "Neuronal Protein Transport", Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Christopher C Reimann
- Guest Group, "Neuronal Protein Transport", Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Lisa Seipold
- Biochemisches Institut, Christian Albrechts-Universität Kiel, 24098, Kiel, Germany
| | - Maja Grohe
- Biochemisches Institut, Christian Albrechts-Universität Kiel, 24098, Kiel, Germany
| | - Janike Rabea Bolter
- AG Optobiology, Institute of Biology, Humboldt Universität Zu Berlin, 10115, Berlin, Germany
| | - Flemming Delfs
- Guest Group, "Neuronal Protein Transport", Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Michael Bucher
- Guest Group, "Neuronal Protein Transport", Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Christine E Gee
- Department of Synaptic Physiology, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Michaela Schweizer
- Morphology and Electron Microscopy, Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, ZMNH, 20251, Hamburg, Germany
| | - Paul Saftig
- Biochemisches Institut, Christian Albrechts-Universität Kiel, 24098, Kiel, Germany.
| | - Marina Mikhaylova
- AG Optobiology, Institute of Biology, Humboldt Universität Zu Berlin, 10115, Berlin, Germany.
- Guest Group, "Neuronal Protein Transport", Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany.
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Agni MB, Hegde PS, Rai P, Sadananda M, K M DG. Astaxanthin and DHA Supplementation Modulates the Maternal Undernutrition-induced Impairment of Cognitive Behavior and Synaptic Plasticity in Adult Life of Offspring's -Exploring the Molecular Mechanism. Mol Neurobiol 2024:10.1007/s12035-024-04147-y. [PMID: 38578356 DOI: 10.1007/s12035-024-04147-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 03/23/2024] [Indexed: 04/06/2024]
Abstract
Maternal nutrition was recognized as a significant part of brain growth and maturation in most mammalian species. Timely intervention with suitable nutraceuticals would provide long-term health benefits. We aim to unravel the molecular mechanisms of perinatal undernutrition-induced impairments in cognition and synaptic plasticity, employing animal model based on dietary nutraceutical supplementation. We treated undernourished dams at their gestational, lactational, and at both the time point with Astaxanthin (AsX) and Docosahexaenoic acid (DHA), and their pups were used as experimental animals. We evaluated the cognitive function by subjecting the pups to behavioral tests in their adult life. In addition, we assessed the expression of genes in the hippocampus related to cognitive function and synaptic plasticity. Our results showed downregulation of Brain-derived neurotrophic factor (BDNF), Neurotrophin-3 (NT-3), cAMP response-element-binding protein (CREB), and uncoupling protein-2 (UCP2) gene expression in pups born to undernourished dams in their adult life, which AsX and DHA modulated. Maternal AsX and DHA supplementation ameliorated the undernutrition-induced learning impairment in novel object recognition (NOR) tests and partially baited radial arm maze (RAM) tasks in offspring's. The expressions of Synapsin-1 and PSD-95 decreased in perinatally undernourished groups compared to control and AsX-DHA treated groups at CA1, CA2, CA3, and DG. AsX and DHA supplementation upregulated BDNF, NT-3, CREB, and UCP2 gene expressions in perinatally undernourished rats, which are involved in intracellular signaling cascades like Ras, PI3K, and PLC. The results of our study give new insights into neuronal differentiation, survival, and plasticity, indicating that the perinatal period is the critical time for reversing maternal undernutrition-induced cognitive impairment in offspring's.
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Affiliation(s)
- Megha Bhat Agni
- Nitte (Deemed to be University), Department of Physiology, KS Hegde Medical Academy, Deralakatte, Mangalore, Karnataka, 575018, India
| | - Pramukh Subrahmanya Hegde
- Nitte (Deemed to be University), Department of Physiology, KS Hegde Medical Academy, Deralakatte, Mangalore, Karnataka, 575018, India
| | - Praveen Rai
- Nitte (Deemed to be University), Department of Infectious Diseases & Microbial Genomics, Nitte University Centre for Science Education and Research (NUCSER), Mangalore, Karnataka, 575018, India
| | - Monika Sadananda
- Biotechnology Unit, Department of Biosciences, Mangalore University, Mangalagangothri, 574199, Karnataka, India
| | - Damodara Gowda K M
- Nitte (Deemed to be University), Department of Physiology, KS Hegde Medical Academy, Deralakatte, Mangalore, Karnataka, 575018, India.
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Luna-Munguia H, Gasca-Martinez D, Garay-Cortes A, Coutiño D, Regalado M, de Los Rios E, Villaseñor P, Hidalgo-Flores F, Flores-Guapo K, Benito BY, Concha L. Selective Medial Septum Lesions in Healthy Rats Induce Longitudinal Changes in Microstructure of Limbic Regions, Behavioral Alterations, and Increased Susceptibility to Status Epilepticus. Mol Neurobiol 2024:10.1007/s12035-024-04069-9. [PMID: 38443731 DOI: 10.1007/s12035-024-04069-9] [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: 09/25/2023] [Accepted: 02/26/2024] [Indexed: 03/07/2024]
Abstract
Septo-hippocampal pathway, crucial for physiological functions and involved in epilepsy. Clinical monitoring during epileptogenesis is complicated. We aim to evaluate tissue changes after lesioning the medial septum (MS) of normal rats and assess how the depletion of specific neuronal populations alters the animals' behavior and susceptibility to establishing a pilocarpine-induced status epilepticus. Male Sprague-Dawley rats were injected into the MS with vehicle or saporins (to deplete GABAergic or cholinergic neurons; n = 16 per group). Thirty-two animals were used for diffusion tensor imaging (DTI); scanned before surgery and 14 and 49 days post-injection. Fractional anisotropy and apparent diffusion coefficient were evaluated in the fimbria, dorsal hippocampus, ventral hippocampus, dorso-medial thalamus, and amygdala. Between scans 2 and 3, animals were submitted to diverse behavioral tasks. Stainings were used to analyze tissue alterations. Twenty-four different animals received pilocarpine to evaluate the latency and severity of the status epilepticus 2 weeks after surgery. Additionally, eight different animals were only used to evaluate the neuronal damage inflicted on the MS 1 week after the molecular surgery. Progressive changes in DTI parameters in both white and gray matter structures of the four evaluated groups were observed. Behaviorally, the GAT1-saporin injection impacted spatial memory formation, while 192-IgG-saporin triggered anxiety-like behaviors. Histologically, the GABAergic toxin also induced aberrant mossy fiber sprouting, tissue damage, and neuronal death. Regarding the pilocarpine-induced status epilepticus, this agent provoked an increased mortality rate. Selective septo-hippocampal modulation impacts the integrity of limbic regions crucial for certain behavioral skills and could represent a precursor for epilepsy development.
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Affiliation(s)
- Hiram Luna-Munguia
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico.
| | - Deisy Gasca-Martinez
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
- Unidad de Analisis Conductual, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
| | - Alejandra Garay-Cortes
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
| | - Daniela Coutiño
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
| | - Mirelta Regalado
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
| | - Ericka de Los Rios
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
- Unidad de Microscopia, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
| | - Paulina Villaseñor
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
| | - Fernando Hidalgo-Flores
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
| | - Karen Flores-Guapo
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
| | - Brandon Yair Benito
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
| | - Luis Concha
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, 76230, Queretaro, Mexico
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4
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Pelkey KA, Vargish GA, Pellegrini LV, Calvigioni D, Chapeton J, Yuan X, Hunt S, Cummins AC, Eldridge MAG, Pickel J, Chittajallu R, Averbeck BB, Tóth K, Zaghloul K, McBain CJ. Evolutionary conservation of hippocampal mossy fiber synapse properties. Neuron 2023; 111:3802-3818.e5. [PMID: 37776852 PMCID: PMC10841147 DOI: 10.1016/j.neuron.2023.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 07/03/2023] [Accepted: 09/06/2023] [Indexed: 10/02/2023]
Abstract
Various specialized structural/functional properties are considered essential for contextual memory encoding by hippocampal mossy fiber (MF) synapses. Although investigated to exquisite detail in model organisms, synapses, including MFs, have undergone minimal functional interrogation in humans. To determine the translational relevance of rodent findings, we evaluated MF properties within human tissue resected to treat epilepsy. Human MFs exhibit remarkably similar hallmark features to rodents, including AMPA receptor-dominated synapses with small contributions from NMDA and kainate receptors, large dynamic range with strong frequency facilitation, NMDA receptor-independent presynaptic long-term potentiation, and strong cyclic AMP (cAMP) sensitivity of release. Array tomography confirmed the evolutionary conservation of MF ultrastructure. The astonishing congruence of rodent and human MF core features argues that the basic MF properties delineated in animal models remain critical to human MF function. Finally, a selective deficit in GABAergic inhibitory tone onto human MF postsynaptic targets suggests that unrestrained detonator excitatory drive contributes to epileptic circuit hyperexcitability.
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Affiliation(s)
- Kenneth A Pelkey
- Eunice Kennedy Shriver National Institute of Child Health and Human Development Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Geoffrey A Vargish
- Eunice Kennedy Shriver National Institute of Child Health and Human Development Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA
| | - Leonardo V Pellegrini
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada
| | - Daniela Calvigioni
- Eunice Kennedy Shriver National Institute of Child Health and Human Development Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA
| | - Julio Chapeton
- National Institute of Neurological Disorders and Stroke Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiaoqing Yuan
- Eunice Kennedy Shriver National Institute of Child Health and Human Development Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA
| | - Steven Hunt
- Eunice Kennedy Shriver National Institute of Child Health and Human Development Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alex C Cummins
- National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mark A G Eldridge
- National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - James Pickel
- National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ramesh Chittajallu
- Eunice Kennedy Shriver National Institute of Child Health and Human Development Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bruno B Averbeck
- National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Katalin Tóth
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada
| | - Kareem Zaghloul
- National Institute of Neurological Disorders and Stroke Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chris J McBain
- Eunice Kennedy Shriver National Institute of Child Health and Human Development Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA.
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5
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Griego E, Galván EJ. BDNF and Lactate as Modulators of Hippocampal CA3 Network Physiology. Cell Mol Neurobiol 2023; 43:4007-4022. [PMID: 37874456 DOI: 10.1007/s10571-023-01425-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 10/14/2023] [Indexed: 10/25/2023]
Abstract
Growing evidence supports the notion that brain-derived neurotrophic factor (BDNF) and lactate are potent modulators of mammalian brain function. The modulatory actions of those biomolecules influence a wide range of neuronal responses, from the shaping of neuronal excitability to the induction and expression of structural and synaptic plasticity. The biological actions of BDNF and lactate are mediated by their cognate receptors and specific transporters located in the neuronal membrane. Canonical functions of BDNF occur via the tropomyosin-related kinase B receptor (TrkB), whereas lactate acts via monocarboxylate transporters or the hydroxycarboxylic acid receptor 1 (HCAR1). Both receptors are highly expressed in the central nervous system, and some of their physiological actions are particularly well characterized in the hippocampus, a brain structure involved in the neurophysiology of learning and memory. The multifarious neuronal circuitry between the axons of the dentate gyrus granule cells, mossy fibers (MF), and pyramidal neurons of area CA3 is of great interest given its role in specific mnemonic processes and involvement in a growing number of brain disorders. Whereas the modulation exerted by BDNF via TrkB has been extensively studied, the influence of lactate via HCAR1 on the properties of the MF-CA3 circuit is an emerging field. In this review, we discuss the role of both systems in the modulation of brain physiology, with emphasis on the hippocampal CA3 network. We complement this review with original data that suggest cross-modulation is exerted by these two independent neuromodulatory systems.
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Affiliation(s)
- Ernesto Griego
- Departamento de Farmacobiología, Cinvestav Sur, Mexico City, Mexico.
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, USA.
- Departamento de Farmacobiología, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional, Calzada de los Tenorios No. 235, Col. Granjas Coapa, C.P. 14330, Mexico City, Mexico.
| | - Emilio J Galván
- Departamento de Farmacobiología, Cinvestav Sur, Mexico City, Mexico
- Centro de Investigaciones sobre el Envejecimiento, Mexico City, Mexico
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Norman CA, Krishnakumar SS, Timofeeva Y, Volynski KE. The release of inhibition model reproduces kinetics and plasticity of neurotransmitter release in central synapses. Commun Biol 2023; 6:1091. [PMID: 37891212 PMCID: PMC10611806 DOI: 10.1038/s42003-023-05445-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
Calcium-evoked release of neurotransmitters from synaptic vesicles (SVs) is catalysed by SNARE proteins. The predominant view is that, at rest, complete assembly of SNARE complexes is inhibited ('clamped') by synaptotagmin and complexin molecules. Calcium binding by synaptotagmins releases this fusion clamp and triggers fast SV exocytosis. However, this model has not been quantitatively tested over physiological timescales. Here we describe an experimentally constrained computational modelling framework to quantitatively assess how the molecular architecture of the fusion clamp affects SV exocytosis. Our results argue that the 'release-of-inhibition' model can indeed account for fast calcium-activated SV fusion, and that dual binding of synaptotagmin-1 and synaptotagmin-7 to the same SNARE complex enables synergistic regulation of the kinetics and plasticity of neurotransmitter release. The developed framework provides a powerful and adaptable tool to link the molecular biochemistry of presynaptic proteins to physiological data and efficiently test the plausibility of calcium-activated neurotransmitter release models.
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Affiliation(s)
- Christopher A Norman
- University College London Institute of Neurology, University College London, London, WC1N 3BG, UK
- Department of Computer Science, University of Warwick, Coventry, CV4 7AL, UK
- Mathematics for Real-World Systems Centre for Doctoral Training, University of Warwick, Coventry, CV4 7AL, UK
| | - Shyam S Krishnakumar
- University College London Institute of Neurology, University College London, London, WC1N 3BG, UK.
- Department of Neurology, Yale Nanobiology Institute, Yale University School of Medicine, New Haven, CT, 06510, USA.
| | - Yulia Timofeeva
- University College London Institute of Neurology, University College London, London, WC1N 3BG, UK.
- Department of Computer Science, University of Warwick, Coventry, CV4 7AL, UK.
| | - Kirill E Volynski
- University College London Institute of Neurology, University College London, London, WC1N 3BG, UK.
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, 06510, USA.
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Kopsick JD, Tecuatl C, Moradi K, Attili SM, Kashyap HJ, Xing J, Chen K, Krichmar JL, Ascoli GA. Robust Resting-State Dynamics in a Large-Scale Spiking Neural Network Model of Area CA3 in the Mouse Hippocampus. Cognit Comput 2023; 15:1190-1210. [PMID: 37663748 PMCID: PMC10473858 DOI: 10.1007/s12559-021-09954-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 10/10/2021] [Indexed: 12/19/2022]
Abstract
Hippocampal area CA3 performs the critical auto-associative function underlying pattern completion in episodic memory. Without external inputs, the electrical activity of this neural circuit reflects the spontaneous spiking interplay among glutamatergic pyramidal neurons and GABAergic interneurons. However, the network mechanisms underlying these resting-state firing patterns are poorly understood. Leveraging the Hippocampome.org knowledge base, we developed a data-driven, large-scale spiking neural network (SNN) model of mouse CA3 with 8 neuron types, 90,000 neurons, 51 neuron-type specific connections, and 250,000,000 synapses. We instantiated the SNN in the CARLsim4 multi-GPU simulation environment using the Izhikevich and Tsodyks-Markram formalisms for neuronal and synaptic dynamics, respectively. We analyzed the resultant population activity upon transient activation. The SNN settled into stable oscillations with a biologically plausible grand-average firing frequency, which was robust relative to a wide range of transient activation. The diverse firing patterns of individual neuron types were consistent with existing knowledge of cell type-specific activity in vivo. Altered network structures that lacked neuron- or connection-type specificity were neither stable nor robust, highlighting the importance of neuron type circuitry. Additionally, external inputs reflecting dentate mossy fibers shifted the observed rhythms to the gamma band. We freely released the CARLsim4-Hippocampome framework on GitHub to test hippocampal hypotheses. Our SNN may be useful to investigate the circuit mechanisms underlying the computational functions of CA3. Moreover, our approach can be scaled to the whole hippocampal formation, which may contribute to elucidating how the unique neuronal architecture of this system subserves its crucial cognitive roles.
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Affiliation(s)
- Jeffrey D. Kopsick
- Interdepartmental Program in Neuroscience, George Mason University, Fairfax, VA, USA
| | - Carolina Tecuatl
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Fairfax, VA, USA
| | - Keivan Moradi
- Interdepartmental Program in Neuroscience, George Mason University, Fairfax, VA, USA
| | - Sarojini M. Attili
- Interdepartmental Program in Neuroscience, George Mason University, Fairfax, VA, USA
| | - Hirak J. Kashyap
- Department of Computer Science, University of California, Irvine, Irvine, CA, USA
| | - Jinwei Xing
- Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, USA
| | - Kexin Chen
- Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, USA
| | - Jeffrey L. Krichmar
- Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, USA
- Department of Computer Science, University of California, Irvine, Irvine, CA, USA
| | - Giorgio A. Ascoli
- Interdepartmental Program in Neuroscience, George Mason University, Fairfax, VA, USA
- Bioengineering Department, Volgenau School of Engineering, George Mason University, Fairfax, VA, USA
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8
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Kharod SC, Monday HR, Yoon YJ, Castillo PE. Protocol to study presynaptic protein synthesis in ex vivo mouse hippocampal slices using HaloTag technology. STAR Protoc 2023; 4:101986. [PMID: 36853723 PMCID: PMC9871327 DOI: 10.1016/j.xpro.2022.101986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/20/2022] [Accepted: 12/13/2022] [Indexed: 01/21/2023] Open
Abstract
Presynaptic boutons in the mammalian brain are typically small and difficult to manipulate and study. Here, we present a protocol applying HaloTag self-labeling technology to detect de novo local protein synthesis in intact presynaptic mossy fiber boutons from acute mouse hippocampal slices. We describe stereotaxic injection of HaloTag-expressing virus into the brain region of interest, followed by brain slice preparation. We then detail the labeling of HaloTag-fused protein and image acquisition to visualize the labeled protein in an intact circuit. For complete details on the use and execution of this protocol, please refer to Monday et al. (2022).1.
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Affiliation(s)
- Shivani C Kharod
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA
| | - Hannah R Monday
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA
| | - Young J Yoon
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA.
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA.
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9
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Hansen M, Simon KR, Strack J, He X, Noble KG, Merz EC. Socioeconomic disparities in sleep duration are associated with cortical thickness in children. Brain Behav 2023; 13:e2859. [PMID: 36575851 PMCID: PMC9927856 DOI: 10.1002/brb3.2859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/11/2022] [Accepted: 12/06/2022] [Indexed: 12/29/2022] Open
Abstract
INTRODUCTION Disrupted sleep has been consistently linked with lower academic achievement and worse mental health in children. Less is understood about sleep as a potential factor underlying socioeconomic differences in brain morphometry in children. The goals of this study were to investigate the associations among socioeconomic factors, sleep duration, and brain morphometry in children, and to examine the roles of the sleep environment and family routines in these associations. METHODS Participants were 5- to 9-year-old children from socioeconomically diverse families (N = 94; 61% female). Parents reported on children's weekday and weekend sleep durations, sleep environment, and family routines. High-resolution, T1-weighted structural magnetic resonance imaging (MRI) data were acquired. Analyses focused on cortical thickness, cortical surface area, and amygdala and hippocampal volume. RESULTS Results indicated that lower family income-to-needs ratio and parental education were significantly associated with shorter weekday sleep duration in children. Shorter weekday sleep duration was significantly associated with reduced thickness in the left middle temporal, right postcentral, and right superior frontal cortices and smaller basolateral but not centromedial amygdala volume. Family routines significantly mediated the associations of family income-to-needs ratio and parental education with weekday sleep duration in children. CONCLUSION These results contribute to our understanding of sleep factors as proximal mechanisms through which socioeconomic context may alter neural development during childhood.
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Affiliation(s)
- Melissa Hansen
- Department of PsychologyColorado State UniversityFort CollinsColoradoUSA
| | - Katrina R. Simon
- Department of Human DevelopmentTeachers College, Columbia UniversityNew YorkUSA
| | - Jordan Strack
- Department of PsychologyColorado State UniversityFort CollinsColoradoUSA
| | - Xiaofu He
- Department of PsychiatryColumbia University Irving Medical CenterNew YorkUSA
| | - Kimberly G. Noble
- Department of Human DevelopmentTeachers College, Columbia UniversityNew YorkUSA
| | - Emily C. Merz
- Department of PsychologyColorado State UniversityFort CollinsColoradoUSA
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10
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Monday HR, Kharod SC, Yoon YJ, Singer RH, Castillo PE. Presynaptic FMRP and local protein synthesis support structural and functional plasticity of glutamatergic axon terminals. Neuron 2022; 110:2588-2606.e6. [PMID: 35728596 PMCID: PMC9391299 DOI: 10.1016/j.neuron.2022.05.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 03/31/2022] [Accepted: 05/26/2022] [Indexed: 10/18/2022]
Abstract
Learning and memory rely on long-lasting, synapse-specific modifications. Although postsynaptic forms of plasticity typically require local protein synthesis, whether and how local protein synthesis contributes to presynaptic changes remain unclear. Here, we examined the mouse hippocampal mossy fiber (MF)-CA3 synapse, which expresses both structural and functional presynaptic plasticity and contains presynaptic fragile X messenger ribonucleoprotein (FMRP), an RNA-binding protein involved in postsynaptic protein-synthesis-dependent plasticity. We report that MF boutons contain ribosomes and synthesize protein locally. The long-term potentiation of MF-CA3 synaptic transmission (MF-LTP) was associated with the translation-dependent enlargement of MF boutons. Remarkably, increasing in vitro or in vivo MF activity enhanced the protein synthesis in MFs. Moreover, the deletion of presynaptic FMRP blocked structural and functional MF-LTP, suggesting that FMRP is a critical regulator of presynaptic MF plasticity. Thus, presynaptic FMRP and protein synthesis dynamically control presynaptic structure and function in the mature mammalian brain.
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Affiliation(s)
- Hannah R Monday
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA.
| | - Shivani C Kharod
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA
| | - Young J Yoon
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA; Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA
| | - Robert H Singer
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, NY 10461, USA.
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11
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Shahoha M, Cohen R, Ben-Simon Y, Ashery U. cAMP-Dependent Synaptic Plasticity at the Hippocampal Mossy Fiber Terminal. Front Synaptic Neurosci 2022; 14:861215. [PMID: 35444523 PMCID: PMC9013808 DOI: 10.3389/fnsyn.2022.861215] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/23/2022] [Indexed: 11/24/2022] Open
Abstract
Cyclic adenosine monophosphate (cAMP) is a crucial second messenger involved in both pre- and postsynaptic plasticity in many neuronal types across species. In the hippocampal mossy fiber (MF) synapse, cAMP mediates presynaptic long-term potentiation and depression. The main cAMP-dependent signaling pathway linked to MF synaptic plasticity acts via the activation of the protein kinase A (PKA) molecular cascade. Accordingly, various downstream putative synaptic PKA target proteins have been linked to cAMP-dependent MF synaptic plasticity, such as synapsin, rabphilin, synaptotagmin-12, RIM1a, tomosyn, and P/Q-type calcium channels. Regulating the expression of some of these proteins alters synaptic release probability and calcium channel clustering, resulting in short- and long-term changes to synaptic efficacy. However, despite decades of research, the exact molecular mechanisms by which cAMP and PKA exert their influences in MF terminals remain largely unknown. Here, we review current knowledge of different cAMP catalysts and potential downstream PKA-dependent molecular cascades, in addition to non-canonical cAMP-dependent but PKA-independent cascades, which might serve as alternative, compensatory or competing pathways to the canonical PKA cascade. Since several other central synapses share a similar form of presynaptic plasticity with the MF, a better description of the molecular mechanisms governing MF plasticity could be key to understanding the relationship between the transcriptional and computational levels across brain regions.
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Affiliation(s)
- Meishar Shahoha
- Faculty of Life Sciences, School of Neurobiology, Biochemistry and Biophysics, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Ronni Cohen
- Faculty of Life Sciences, School of Neurobiology, Biochemistry and Biophysics, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Yoav Ben-Simon
- Department of Neurophysiology, Vienna Medical University, Vienna, Austria
- *Correspondence: Yoav Ben-Simon,
| | - Uri Ashery
- Faculty of Life Sciences, School of Neurobiology, Biochemistry and Biophysics, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- Uri Ashery,
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12
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Tanaka M, Sakaba T, Miki T. Quantal analysis estimates docking site occupancy determining short-term depression at hippocampal glutamatergic synapses. J Physiol 2021; 599:5301-5327. [PMID: 34705277 DOI: 10.1113/jp282235] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/20/2021] [Indexed: 12/23/2022] Open
Abstract
Before fusion, synaptic vesicles (SVs) pause at discrete release/docking sites. During repetitive stimulation, the probability of site occupancy changes following SV fusion and replenishment. The occupancy probability is considered to be one of the crucial determinants of synaptic strength, but it is difficult to estimate separately because it usually blends with other synaptic parameters. Thus, the contribution of site occupancy to synaptic function, particularly to synaptic depression, remains elusive. Here, we directly estimated the occupancy probability at the hippocampal mossy fibre-CA3 interneuron synapse showing synaptic depression, using statistics of counts of vesicular events detected by deconvolution. We found that this synapse had a particularly high occupancy (∼0.85) with a high release probability of a docked SV (∼0.8) under 3 mm external calcium conditions. Analyses of quantal amplitudes and SV counts indicated that quantal size reduction decreased the amplitudes of all responses in a train to a similar degree, whereas release/docking site number was unchanged during trains, suggesting that quantal size and release/docking site number had little influence on the extent of synaptic depression. Model simulations revealed that the initial occupancy with high release probability and slow replenishment determined the time course of synaptic depression. Consistently, decreasing external calcium concentration reduced both the occupancy and release probability, and the reductions in turn produced less depression. Based on these results, we suggest that the occupancy probability is a crucial determinant of short-term synaptic depression at glutamatergic synapses in the hippocampus. KEY POINTS: The occupancy probability of a release/docking site by a synaptic vesicle at presynaptic terminals is considered to be one of the crucial determinants of synaptic strength, but it is difficult to estimate separately from other synaptic parameters. Here, we directly estimate the occupancy probability at the hippocampal mossy fibre-interneuron synapse using statistics of vesicular events detected by deconvolution. We show that the synapses have particularly high occupancy (0.85) with high release probability (0.8) under high external calcium concentration ([Ca2+ ]o ) conditions, and that both parameter values change with [Ca2+ ]o , shaping synaptic depression. Analyses of the quantal amplitudes and synaptic vesicle counts suggest that quantal sizes and release/docking site number have little influence on the extent of synaptic depression. The results suggest that the occupancy probability is a crucial determinant of short-term synaptic depression at glutamatergic synapses in the hippocampus.
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Affiliation(s)
- Mamoru Tanaka
- Graduate School of Brain Science, Doshisha University, Kyoto, Japan
| | - Takeshi Sakaba
- Graduate School of Brain Science, Doshisha University, Kyoto, Japan
| | - Takafumi Miki
- Graduate School of Brain Science, Doshisha University, Kyoto, Japan.,Organization for Research Initiatives and Development, Doshisha University, Kyoto, Japan
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13
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Twible C, Abdo R, Zhang Q. Astrocyte Role in Temporal Lobe Epilepsy and Development of Mossy Fiber Sprouting. Front Cell Neurosci 2021; 15:725693. [PMID: 34658792 PMCID: PMC8514632 DOI: 10.3389/fncel.2021.725693] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/02/2021] [Indexed: 11/13/2022] Open
Abstract
Epilepsy affects approximately 50 million people worldwide, with 60% of adult epilepsies presenting an onset of focal origin. The most common focal epilepsy is temporal lobe epilepsy (TLE). The role of astrocytes in the presentation and development of TLE has been increasingly studied and discussed within the literature. The most common histopathological diagnosis of TLE is hippocampal sclerosis. Hippocampal sclerosis is characterized by neuronal cell loss within the Cornu ammonis and reactive astrogliosis. In some cases, mossy fiber sprouting may be observed. Mossy fiber sprouting has been controversial in its contribution to epileptogenesis in TLE patients, and the mechanisms surrounding the phenomenon have yet to be elucidated. Several studies have reported that mossy fiber sprouting has an almost certain co-existence with reactive astrogliosis within the hippocampus under epileptic conditions. Astrocytes are known to play an important role in the survival and axonal outgrowth of central and peripheral nervous system neurons, pointing to a potential role of astrocytes in TLE and associated cellular alterations. Herein, we review the recent developments surrounding the role of astrocytes in the pathogenic process of TLE and mossy fiber sprouting, with a focus on proposed signaling pathways and cellular mechanisms, histological observations, and clinical correlations in human patients.
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Affiliation(s)
- Carolyn Twible
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada
| | - Rober Abdo
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada.,Department of Anatomy and Cell Biology, Western University, London, ON, Canada
| | - Qi Zhang
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada.,Department of Pathology and Lab Medicine, London Health Sciences Centre, University Hospital, London, ON, Canada
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14
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Lituma PJ, Kwon HB, Alviña K, Luján R, Castillo PE. Presynaptic NMDA receptors facilitate short-term plasticity and BDNF release at hippocampal mossy fiber synapses. eLife 2021; 10:e66612. [PMID: 34061025 PMCID: PMC8186907 DOI: 10.7554/elife.66612] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 05/28/2021] [Indexed: 01/12/2023] Open
Abstract
Neurotransmitter release is a highly controlled process by which synapses can critically regulate information transfer within neural circuits. While presynaptic receptors - typically activated by neurotransmitters and modulated by neuromodulators - provide a powerful way of fine-tuning synaptic function, their contribution to activity-dependent changes in transmitter release remains poorly understood. Here, we report that presynaptic NMDA receptors (preNMDARs) at mossy fiber boutons in the rodent hippocampus can be activated by physiologically relevant patterns of activity and selectively enhance short-term synaptic plasticity at mossy fiber inputs onto CA3 pyramidal cells and mossy cells, but not onto inhibitory interneurons. Moreover, preNMDARs facilitate brain-derived neurotrophic factor release and contribute to presynaptic calcium rise. Taken together, our results indicate that by increasing presynaptic calcium, preNMDARs fine-tune mossy fiber neurotransmission and can control information transfer during dentate granule cell burst activity that normally occur in vivo.
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Affiliation(s)
- Pablo J Lituma
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
| | - Hyung-Bae Kwon
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
| | - Karina Alviña
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
| | - Rafael Luján
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), Facultad de Medicina, Universidad Castilla-La ManchaAlbaceteSpain
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of MedicineBronxUnited States
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of MedicineBronxUnited States
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15
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Targeted volumetric single-molecule localization microscopy of defined presynaptic structures in brain sections. Commun Biol 2021; 4:407. [PMID: 33767432 PMCID: PMC7994795 DOI: 10.1038/s42003-021-01939-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 03/03/2021] [Indexed: 11/17/2022] Open
Abstract
Revealing the molecular organization of anatomically precisely defined brain regions is necessary for refined understanding of synaptic plasticity. Although three-dimensional (3D) single-molecule localization microscopy can provide the required resolution, imaging more than a few micrometers deep into tissue remains challenging. To quantify presynaptic active zones (AZ) of entire, large, conditional detonator hippocampal mossy fiber (MF) boutons with diameters as large as 10 µm, we developed a method for targeted volumetric direct stochastic optical reconstruction microscopy (dSTORM). An optimized protocol for fast repeated axial scanning and efficient sequential labeling of the AZ scaffold Bassoon and membrane bound GFP with Alexa Fluor 647 enabled 3D-dSTORM imaging of 25 µm thick mouse brain sections and assignment of AZs to specific neuronal substructures. Quantitative data analysis revealed large differences in Bassoon cluster size and density for distinct hippocampal regions with largest clusters in MF boutons. Pauli et al. develop targeted volumetric dSTORM in order to image large hippocampal mossy fiber boutons (MFBs) in brain slices. They can identify synaptic targets of individual MFBs and measured size and density of Bassoon clusters within individual untruncated MFBs at nanoscopic resolution.
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16
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Lee SH, Lutz D, Drexler D, Frotscher M, Shen J. Differential modulation of short-term plasticity at hippocampal mossy fiber and Schaffer collateral synapses by mitochondrial Ca2. PLoS One 2020; 15:e0240610. [PMID: 33049001 PMCID: PMC7553293 DOI: 10.1371/journal.pone.0240610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 09/29/2020] [Indexed: 11/19/2022] Open
Abstract
Presynaptic mitochondrial Ca2+ plays a critical role in the regulation of synaptic transmission and plasticity. The presynaptic bouton of the hippocampal mossy fiber (MF) is much larger in size than that of the Schaffer collateral (SC) synapse. Here we compare the structural and physiological characteristics of MF and SC presynaptic boutons to reveal functional and mechanistic differences between these two synapses. Our quantitative ultrastructural analysis using electron microscopy show many more mitochondria in MF presynaptic bouton cross-section profiles compared to SC boutons. Consistent with these results, post-tetanic potentiation (PTP), a form of presynaptic short-term plasticity dependent on mitochondrial Ca2+, is reduced by inhibition of mitochondrial Ca2+ release at MF synapses but not at SC synapses. However, blockade of mitochondrial Ca2+ release results in reduction of PTP at SC synapses by disynaptic MF stimulation. Furthermore, inhibition of mitochondrial Ca2+ release selectively decreases frequency facilitation evoked by short trains of presynaptic stimulation at MF synapses, while having no effect at SC synapses. Moreover, depletion of ER Ca2+ stores leads to reduction of PTP at MF synapses, but PTP is unaffected by ER Ca2+ depletion at SC synapses. These findings show that MF and SC synapses differ in presynaptic mitochondrial content as well as mitochondrial Ca2+ dependent synaptic plasticity, highlighting differential regulatory mechanisms of presynaptic plasticity at MF and SC synapses.
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Affiliation(s)
- Sang Hun Lee
- Department of Neurology, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David Lutz
- Institute for Structural Neurobiology, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Dagmar Drexler
- Institute for Structural Neurobiology, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Frotscher
- Institute for Structural Neurobiology, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jie Shen
- Department of Neurology, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Program in Neuroscience, Harvard Medical School, Boston, Massachusetts, United States of America
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17
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Krzywoszyńska K, Witkowska D, Świątek-Kozłowska J, Szebesczyk A, Kozłowski H. General Aspects of Metal Ions as Signaling Agents in Health and Disease. Biomolecules 2020; 10:biom10101417. [PMID: 33036384 PMCID: PMC7600656 DOI: 10.3390/biom10101417] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/30/2020] [Accepted: 10/02/2020] [Indexed: 02/07/2023] Open
Abstract
This review focuses on the current knowledge on the involvement of metal ions in signaling processes within the cell, in both physiological and pathological conditions. The first section is devoted to the recent discoveries on magnesium and calcium-dependent signal transduction-the most recognized signaling agents among metals. The following sections then describe signaling pathways where zinc, copper, and iron play a key role. There are many systems in which changes in intra- and extra-cellular zinc and copper concentrations have been linked to important downstream events, especially in nervous signal transduction. Iron signaling is mostly related with its homeostasis. However, it is also involved in a recently discovered type of programmed cell death, ferroptosis. The important differences in metal ion signaling, and its disease-leading alterations, are also discussed.
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Affiliation(s)
- Karolina Krzywoszyńska
- Institute of Health Sciences, University of Opole, 68 Katowicka St., 45-060 Opole, Poland; (J.Ś.-K.); (A.S.); (H.K.)
- Correspondence: (K.K.); (D.W.); Tel.: +48-77-44-23-549 (K.K); +48-77-44-23-548 (D.W.)
| | - Danuta Witkowska
- Institute of Health Sciences, University of Opole, 68 Katowicka St., 45-060 Opole, Poland; (J.Ś.-K.); (A.S.); (H.K.)
- Correspondence: (K.K.); (D.W.); Tel.: +48-77-44-23-549 (K.K); +48-77-44-23-548 (D.W.)
| | - Jolanta Świątek-Kozłowska
- Institute of Health Sciences, University of Opole, 68 Katowicka St., 45-060 Opole, Poland; (J.Ś.-K.); (A.S.); (H.K.)
| | - Agnieszka Szebesczyk
- Institute of Health Sciences, University of Opole, 68 Katowicka St., 45-060 Opole, Poland; (J.Ś.-K.); (A.S.); (H.K.)
| | - Henryk Kozłowski
- Institute of Health Sciences, University of Opole, 68 Katowicka St., 45-060 Opole, Poland; (J.Ś.-K.); (A.S.); (H.K.)
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie St., 50-383 Wrocław, Poland
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18
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Evaluation of the ameliorative effects of oral administration of metformin on epileptogenesis in the temporal lobe epilepsy model in rats. Life Sci 2020; 257:118066. [PMID: 32652135 DOI: 10.1016/j.lfs.2020.118066] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/26/2020] [Accepted: 07/05/2020] [Indexed: 12/14/2022]
Abstract
AIMS Understanding the underlying molecular mechanisms involved in epileptogenesis is necessary to target the best therapeutic interventions in epilepsy. Recently, it has been postulated that metformin, an old antidiabetic oral drug, has anti-seizure properties mostly due to its antioxidant activities. This study was designed to evaluate the ameliorative effects of metformin on the progression of epilepsy in the temporal lobe epilepsy model in rats. MAIN METHODS Temporal lobe Epilepsy was induced by intracerebroventricular microinjection of kainic acid. Metformin was orally administered for two weeks before induction of epilepsy. Anti-epileptogenic activity of metformin was evaluated by intracranial electroencepholography (IEEG) recording to detect spontaneous seizures, mossy fiber sprouting by Timm staining, neurogenesis by BrdU staining. KEY FINDINGS Oral administration of metformin prior to kainite-induced status epilepticus blocked the variant characterizations of epileptogenesis like neuronal cell death, aberrant neurogenesis, mossy fiber sprouting, and spontaneous seizures. SIGNIFICANCE These findings indicate that metformin has potential anti-epileptogenic properties in temporal lobe epilepsy.
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19
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Chamberland S, Timofeeva Y, Evstratova A, Norman CA, Volynski K, Tóth K. Slow-decaying presynaptic calcium dynamics gate long-lasting asynchronous release at the hippocampal mossy fiber to CA3 pyramidal cell synapse. Synapse 2020; 74:e22178. [PMID: 32598500 PMCID: PMC7685170 DOI: 10.1002/syn.22178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 06/23/2020] [Accepted: 06/24/2020] [Indexed: 01/21/2023]
Abstract
Action potentials trigger two modes of neurotransmitter release, with a fast synchronous component and a temporally delayed asynchronous release. Asynchronous release contributes to information transfer at synapses, including at the hippocampal mossy fiber (MF) to CA3 pyramidal cell synapse where it controls the timing of postsynaptic CA3 pyramidal neuron firing. Here, we identified and characterized the main determinants of asynchronous release at the MF–CA3 synapse. We found that asynchronous release at MF–CA3 synapses can last on the order of seconds following repetitive MF stimulation. Elevating the stimulation frequency or the external Ca2+ concentration increased the rate of asynchronous release, thus, arguing that presynaptic Ca2+ dynamics is the major determinant of asynchronous release rate. Direct MF bouton Ca2+ imaging revealed slow Ca2+ decay kinetics of action potential (AP) burst‐evoked Ca2+ transients. Finally, we observed that asynchronous release was preferentially mediated by Ca2+ influx through P/Q‐type voltage‐gated Ca2+ channels, while the contribution of N‐type VGCCs was limited. Overall, our results uncover the determinants of long‐lasting asynchronous release from MF terminals and suggest that asynchronous release could influence CA3 pyramidal cell firing up to seconds following termination of granule cell bursting.
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Affiliation(s)
- Simon Chamberland
- CERVO Brain Research Center, Department of Psychiatry and Neuroscience, Université Laval, Quebec, QC, Canada
| | - Yulia Timofeeva
- Department of Computer Science, University of Warwick, Coventry, UK.,Centre for Complexity Science, University of Warwick, Coventry, UK.,University College London Institute of Neurology, University College London, London, UK
| | - Alesya Evstratova
- CERVO Brain Research Center, Department of Psychiatry and Neuroscience, Université Laval, Quebec, QC, Canada
| | - Christopher A Norman
- Mathematics for Real-World Systems Centre for Doctoral Training, University of Warwick, Coventry, UK
| | - Kirill Volynski
- University College London Institute of Neurology, University College London, London, UK
| | - Katalin Tóth
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
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20
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Tyrtyshnaia A, Manzhulo I, Konovalova S, Zagliadkina A. Neuropathic Pain Causes a Decrease in the Dendritic Tree Complexity of Hippocampal CA3 Pyramidal Neurons. Cells Tissues Organs 2020; 208:89-100. [DOI: 10.1159/000506812] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 02/26/2020] [Indexed: 11/19/2022] Open
Abstract
The International Pain Association defines neuropathic pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage.” Recent studies show that chronic neuropathic pain causes both morphological and functional changes within brain structures. Due to the impact of supraspinal centers on pain signal processing, patients with chronic pain often suffer from depression, anxiety, memory impairment, and learning disabilities. Changes in hippocampal neuronal and glial plasticity can play a substantial role in the development of these symptoms. Given the special role of the CA3 hippocampal area in chronic stress reactions, we suggested that this region may undergo significant morphological changes as a result of persistent pain. Since the CA3 area is involved in the implementation of hippocampus-dependent memory, changes in the neuronal morphology can cause cognitive impairment observed in chronic neuropathic pain. This study aimed to elucidate the structural and plastic changes within the hippocampus associated with dendritic tree atrophy of CA3 pyramidal neurons in mice with chronic sciatic nerve constriction. Behavioral testing revealed impaired working and long-term memory in mice with a chronic constriction injury. Using the Golgi-Cox method, we revealed a decrease in the number of branches and dendritic length of CA3 pyramidal neurons. The dendritic spine number was decreased, predominantly due to a reduction in mushroom spines. An immunohistochemical study showed changes in astro- and microglial activity, which could affect the morphology of neurons both directly and indirectly via the regulation of neurotrophic factor synthesis. Using ELISA, we found a decrease in brain-derived neurotrophic factor production and an increase in neurotrophin-3 production. Morphological and biochemical changes in the CA3 area are accompanied by impaired working and long-term memory of animals. Thus, we can conclude that morphological and biochemical changes within the CA3 hippocampal area may underlie the cognitive impairment in neuropathic pain.
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21
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Maglione M, Kochlamazashvili G, Eisenberg T, Rácz B, Michael E, Toppe D, Stumpf A, Wirth A, Zeug A, Müller FE, Moreno-Velasquez L, Sammons RP, Hofer SJ, Madeo F, Maritzen T, Maier N, Ponimaskin E, Schmitz D, Haucke V, Sigrist SJ. Spermidine protects from age-related synaptic alterations at hippocampal mossy fiber-CA3 synapses. Sci Rep 2019; 9:19616. [PMID: 31873156 PMCID: PMC6927957 DOI: 10.1038/s41598-019-56133-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 12/06/2019] [Indexed: 12/15/2022] Open
Abstract
Aging is associated with functional alterations of synapses thought to contribute to age-dependent memory impairment (AMI). While therapeutic avenues to protect from AMI are largely elusive, supplementation of spermidine, a polyamine normally declining with age, has been shown to restore defective proteostasis and to protect from AMI in Drosophila. Here we demonstrate that dietary spermidine protects from age-related synaptic alterations at hippocampal mossy fiber (MF)-CA3 synapses and prevents the aging-induced loss of neuronal mitochondria. Dietary spermidine rescued age-dependent decreases in synaptic vesicle density and largely restored defective presynaptic MF-CA3 long-term potentiation (LTP) at MF-CA3 synapses (MF-CA3) in aged animals. In contrast, spermidine failed to protect CA3-CA1 hippocampal synapses characterized by postsynaptic LTP from age-related changes in function and morphology. Our data demonstrate that dietary spermidine attenuates age-associated deterioration of MF-CA3 synaptic transmission and plasticity. These findings provide a physiological and molecular basis for the future therapeutic usage of spermidine.
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Affiliation(s)
- Marta Maglione
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, 14195, Berlin, Germany
- Department of Molecular Pharmacology and Cell Biology, Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany
| | - Gaga Kochlamazashvili
- Department of Molecular Pharmacology and Cell Biology, Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Tobias Eisenberg
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010, Graz, Austria
- BioTechMed-Graz, 8010, Graz, Austria
| | - Bence Rácz
- Department of Anatomy and Histology, University of Veterinary Medicine Budapest, 1078, Budapest, Hungary
| | - Eva Michael
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, 14195, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany
| | - David Toppe
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, 14195, Berlin, Germany
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany
| | - Alexander Stumpf
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117, Berlin, Germany
| | - Alexander Wirth
- Cellular Neurophysiology, Hannover Medical School, 30625, Hannover, Germany
| | - André Zeug
- Cellular Neurophysiology, Hannover Medical School, 30625, Hannover, Germany
| | - Franziska E Müller
- Cellular Neurophysiology, Hannover Medical School, 30625, Hannover, Germany
| | - Laura Moreno-Velasquez
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117, Berlin, Germany
| | - Rosanna P Sammons
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117, Berlin, Germany
| | - Sebastian J Hofer
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010, Graz, Austria
- BioTechMed-Graz, 8010, Graz, Austria
| | - Frank Madeo
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, 8010, Graz, Austria
- BioTechMed-Graz, 8010, Graz, Austria
| | - Tanja Maritzen
- Department of Molecular Pharmacology and Cell Biology, Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Nikolaus Maier
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117, Berlin, Germany
| | - Evgeni Ponimaskin
- Cellular Neurophysiology, Hannover Medical School, 30625, Hannover, Germany
| | - Dietmar Schmitz
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10117, Berlin, Germany
| | - Volker Haucke
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, 14195, Berlin, Germany.
- Department of Molecular Pharmacology and Cell Biology, Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany.
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany.
| | - Stephan J Sigrist
- Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, 14195, Berlin, Germany.
- NeuroCure Cluster of Excellence, Charité Universitätsmedizin, 10117, Berlin, Germany.
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22
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Soares C, Trotter D, Longtin A, Béïque JC, Naud R. Parsing Out the Variability of Transmission at Central Synapses Using Optical Quantal Analysis. Front Synaptic Neurosci 2019; 11:22. [PMID: 31474847 PMCID: PMC6702664 DOI: 10.3389/fnsyn.2019.00022] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 07/31/2019] [Indexed: 12/11/2022] Open
Abstract
Properties of synaptic release dictates the core of information transfer in neural circuits. Despite decades of technical and theoretical advances, distinguishing bona fide information content from the multiple sources of synaptic variability remains a challenging problem. Here, we employed a combination of computational approaches with cellular electrophysiology, two-photon uncaging of MNI-Glutamate and imaging at single synapses. We describe and calibrate the use of the fluorescent glutamate sensor iGluSnFR and found that its kinetic profile is close to that of AMPA receptors, therefore providing several distinct advantages over slower methods relying on NMDA receptor activation (i.e., chemical or genetically encoded calcium indicators). Using an array of statistical methods, we further developed, and validated on surrogate data, an expectation-maximization algorithm that, by biophysically constraining release variability, extracts the quantal parameters n (maximum number of released vesicles) and p (unitary probability of release) from single-synapse iGluSnFR-mediated transients. Together, we present a generalizable mathematical formalism which, when applied to optical recordings, paves the way to an increasingly precise investigation of information transfer at central synapses.
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Affiliation(s)
- Cary Soares
- Department of Cellular and Molecular Medicine, uOttawa Brain and Mind Research Institute, Center for Neural Dynamics, University of Ottawa, Ottawa, ON, Canada
| | - Daniel Trotter
- Department of Physics, University of Ottawa, Ottawa, ON, Canada
| | - André Longtin
- Department of Cellular and Molecular Medicine, uOttawa Brain and Mind Research Institute, Center for Neural Dynamics, University of Ottawa, Ottawa, ON, Canada
- Department of Physics, University of Ottawa, Ottawa, ON, Canada
| | - Jean-Claude Béïque
- Department of Cellular and Molecular Medicine, uOttawa Brain and Mind Research Institute, Center for Neural Dynamics, University of Ottawa, Ottawa, ON, Canada
| | - Richard Naud
- Department of Cellular and Molecular Medicine, uOttawa Brain and Mind Research Institute, Center for Neural Dynamics, University of Ottawa, Ottawa, ON, Canada
- Department of Physics, University of Ottawa, Ottawa, ON, Canada
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23
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Soluble Epoxide Hydrolase Inhibition Attenuates Excitotoxicity Involving 14,15-Epoxyeicosatrienoic Acid–Mediated Astrocytic Survival and Plasticity to Preserve Glutamate Homeostasis. Mol Neurobiol 2019; 56:8451-8474. [DOI: 10.1007/s12035-019-01669-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 06/03/2019] [Indexed: 12/15/2022]
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Abstract
Ethanol produces intoxication through actions on numerous molecular and cellular targets. Adaptations involving these and other targets contribute to chronic drug actions that underlie continued and problematic drinking. Among the mechanisms involved in these ethanol actions are alterations in presynaptic mechanisms of synaptic transmission, including presynaptic protein function and excitation-secretion coupling. At synapses in the central nervous system (CNS), excitation-secretion coupling involves ion channel activation followed by vesicle fusion and neurotransmitter release. These mechanisms are altered by presynaptic neurotransmitter receptors and prominently by G protein-coupled receptors (GPCRs). Studies over the last 20-25 years have revealed that acute ethanol exposure alters neurotransmitter secretion, with especially robust effects on synapses that use the neurotransmitter gamma-aminobutyric acid (GABA). Intracellular signaling pathways involving second messengers such as cyclic AMP and calcium are implicated in these acute ethanol actions. Ethanol-induced release of neuropeptides and small molecule neurotransmitters that act on presynaptic GPCRs also contribute to presynaptic potentiation at synapses in the amygdala and hippocampus and inhibition of GABA release in the striatum. Prolonged exposure to ethanol alters neurotransmitter release at many CNS GABAergic and glutamatergic synapses, and changes in GPCR function are implicated in many of these neuroadaptations. These presynaptic neuroadaptations appear to involve compensation for acute drug effects at some synapses, but "allostatic" effects that result in long-term resetting of synaptic efficacy occur at others. Current investigations are determining how presynaptic neuroadaptations contribute to behavioral changes at different stages of alcohol drinking, with increasing focus on circuit adaptations underlying these behaviors. This chapter will discuss the acute and chronic presynaptic effects of ethanol in the CNS, as well as some of the consequences of these effects in amygdala and corticostriatal circuits that are related to excessive seeking/drinking and ethanol abuse.
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Affiliation(s)
- David M Lovinger
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, USA.
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25
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Madar AD, Ewell LA, Jones MV. Pattern separation of spiketrains in hippocampal neurons. Sci Rep 2019; 9:5282. [PMID: 30918288 PMCID: PMC6437159 DOI: 10.1038/s41598-019-41503-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 03/08/2019] [Indexed: 11/30/2022] Open
Abstract
Pattern separation is a process that minimizes overlap between patterns of neuronal activity representing similar experiences. Theoretical work suggests that the dentate gyrus (DG) performs this role for memory processing but a direct demonstration is lacking. One limitation is the difficulty to measure DG inputs and outputs simultaneously. To rigorously assess pattern separation by DG circuitry, we used mouse brain slices to stimulate DG afferents and simultaneously record DG granule cells (GCs) and interneurons. Output spiketrains of GCs are more dissimilar than their input spiketrains, demonstrating for the first time temporal pattern separation at the level of single neurons in the DG. Pattern separation is larger in GCs than in fast-spiking interneurons and hilar mossy cells, and is amplified in CA3 pyramidal cells. Analysis of the neural noise and computational modelling suggest that this form of pattern separation is not explained by simple randomness and arises from specific presynaptic dynamics. Overall, by reframing the concept of pattern separation in dynamic terms and by connecting it to the physiology of different types of neurons, our study offers a new window of understanding in how hippocampal networks might support episodic memory.
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Affiliation(s)
- Antoine D Madar
- Department of Neuroscience, University of Wisconsin, Madison, WI, 53705, USA. .,Department of Neurobiology, Grossman Institute for Neuroscience, Quantitative Biology and Human Behavior, University of Chicago, Chicago, IL, 60637, USA.
| | - Laura A Ewell
- Department of Neuroscience, University of Wisconsin, Madison, WI, 53705, USA.,Institute of Experimental Epileptology and Cognition Research, University of Bonn - Medical Center, Bonn, Germany
| | - Mathew V Jones
- Department of Neuroscience, University of Wisconsin, Madison, WI, 53705, USA
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26
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Hippocampal Mossy Fibers Synapses in CA3 Pyramidal Cells Are Altered at an Early Stage in a Mouse Model of Alzheimer's Disease. J Neurosci 2019; 39:4193-4205. [PMID: 30886015 DOI: 10.1523/jneurosci.2868-18.2019] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 02/20/2019] [Accepted: 03/08/2019] [Indexed: 12/13/2022] Open
Abstract
Early Alzheimer's disease (AD) affects the brain non-uniformly, causing hippocampal memory deficits long before wide-spread brain degeneration becomes evident. Here we addressed whether mossy fiber inputs from the dentate gyrus onto CA3 principal cells are affected in an AD mouse model before amyloid β plaque deposition. We recorded from CA3 pyramidal cells in a slice preparation from 6-month-old male APP/PS1 mice, and studied synaptic properties and intrinsic excitability. In parallel we performed a morphometric analysis of mossy fiber synapses following viral based labeling and 3D-reconstruction. We found that the basal structural and functional properties as well as presynaptic short-term plasticity at mossy fiber synapses are unaltered at 6 months in APP/PS1 mice. However, transient potentiation of synaptic transmission mediated by activity-dependent release of lipids was abolished. Whereas the presynaptic form of mossy fiber long-term potentiation (LTP) was not affected, the postsynaptic LTP of NMDAR-EPSCs was reduced. In addition, we also report an impairment in feedforward inhibition in CA3 pyramidal cells. This study, together with our previous work describing deficits at CA3-CA3 synapses, provides evidence that early AD affects synapses in a projection-dependent manner at the level of a single neuronal population.SIGNIFICANCE STATEMENT Because loss of episodic memory is considered the cognitive hallmark of Alzheimer's disease (AD), it is important to study whether synaptic circuits involved in the encoding of episodic memory are compromised in AD mouse models. Here we probe alterations in the synaptic connections between the dentate gyrus and CA3, which are thought to be critical for enabling episodic memories to be formed and stored in CA3. We found that forms of synaptic plasticity specific to these synaptic connections are markedly impaired at an early stage in a mouse model of AD, before deposition of β amyloid plaques. Together with previous work describing deficits at CA3-CA3 synapses, we provide evidence that early AD affects synapses in an input-dependent manner within a single neuronal population.
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27
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Lovinger DM, Abrahao KP. Synaptic plasticity mechanisms common to learning and alcohol use disorder. ACTA ACUST UNITED AC 2018; 25:425-434. [PMID: 30115764 PMCID: PMC6097767 DOI: 10.1101/lm.046722.117] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/21/2018] [Indexed: 11/24/2022]
Abstract
Alcohol use disorders include drinking problems that span a range from binge drinking to alcohol abuse and dependence. Plastic changes in synaptic efficacy, such as long-term depression and long-term potentiation are widely recognized as mechanisms involved in learning and memory, responses to drugs of abuse, and addiction. In this review, we focus on the effects of chronic ethanol (EtOH) exposure on the induction of synaptic plasticity in different brain regions. We also review findings indicating that synaptic plasticity occurs in vivo during EtOH exposure, with a focus on ex vivo electrophysiological indices of plasticity. Evidence for effects of EtOH-induced or altered synaptic plasticity on learning and memory and EtOH-related behaviors is also reviewed. As this review indicates, there is much work needed to provide more information about the molecular, cellular, circuit, and behavioral consequences of EtOH interactions with synaptic plasticity mechanisms.
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Affiliation(s)
- David M Lovinger
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892, USA
| | - Karina P Abrahao
- Laboratory for Integrative Neuroscience, Division of Intramural Clinical and Biological Research, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892, USA
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28
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França TFA. Plasticity and redundancy in the integration of adult born neurons in the hippocampus. Neurobiol Learn Mem 2018; 155:136-142. [PMID: 30031119 DOI: 10.1016/j.nlm.2018.07.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/05/2018] [Accepted: 07/17/2018] [Indexed: 01/05/2023]
Abstract
Hippocampal neurogenesis (HN) is an extreme form of plasticity that inevitably rewires the hippocampal circuit and this rewiring was put forward as a possible mechanism for neurogenesis' behavioral effects. Here, I critically evaluate multiple lines of evidence to argue that structural plasticity induced by HN is, to a large extent, functionally redundant and thus has limited impact on behavior. The associative plasticity rules along with properties of immature neurons should only allow the survival of new neurons whose pre and postsynaptic partners have correlated activity, leading to functional redundancy. Moreover, non-redundant rewiring, even with its computational benefits, would impair meaningful communication between the hippocampus and other brain regions. This implies that associative plasticity rules constrain structural plasticity induced by neurogenesis, allowing the brain to balance plasticity and stability to maintain proper functioning. It also implies that behavioral effects of HN are mediated by other mechanisms apart from circuit rewiring.
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Affiliation(s)
- Thiago F A França
- Programa de Pós-graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande - FURG, Rio Grande, RS, Brazil; Curso de graduação em Ciências Biológicas, Universidade Federal do Rio Grande -FURG, Rio Grande, RS, Brazil; Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, Brazil.
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29
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Michaelsen‐Preusse K, Feuge J, Korte M. Imbalance of synaptic actin dynamics as a key to fragile X syndrome? J Physiol 2018; 596:2773-2782. [PMID: 29380377 PMCID: PMC6046079 DOI: 10.1113/jp275571] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 01/09/2018] [Indexed: 11/08/2022] Open
Abstract
Our experiences and memories define who we are, and evidence has accumulated that memory formation is dependent on functional and structural adaptations of synaptic structures in our brain. Especially dendritic spines, the postsynaptic compartments of synapses show a strong structure-to-function relationship and a high degree of structural plasticity. Although the molecular mechanisms are not completely understood, it is known that these modifications are highly dependent on the actin cytoskeleton, the major cytoskeletal component of the spine. Given the crucial involvement of actin in these mechanisms, dysregulations of spine actin dynamics (reflected by alterations in dendritic spine morphology) can be found in a variety of neurological disorders ranging from schizophrenia to several forms of autism spectrum disorders such as fragile X syndrome (FXS). FXS is caused by a single mutation leading to an inactivation of the X-linked fragile X mental retardation 1 gene and loss of its gene product, the RNA-binding protein fragile X mental retardation protein 1 (FMRP), which normally can be found both pre- and postsynaptically. FMRP is involved in mRNA transport as well as regulation of local translation at the synapse, and although hundreds of FMRP-target mRNAs could be identified only a very few interactions between FMRP and actin-regulating proteins have been reported and validated. In this review we give an overview of recent work by our lab and others providing evidence that dysregulated actin dynamics might indeed be at the very base of a deeper understanding of neurological disorders ranging from cognitive impairment to the autism spectrum.
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Affiliation(s)
- Kristin Michaelsen‐Preusse
- Zoological Institute, Division of Cellular NeurobiologyTU BraunschweigSpielmannstr. 7Braunschweig38106Germany
| | - Jonas Feuge
- Zoological Institute, Division of Cellular NeurobiologyTU BraunschweigSpielmannstr. 7Braunschweig38106Germany
| | - Martin Korte
- Zoological Institute, Division of Cellular NeurobiologyTU BraunschweigSpielmannstr. 7Braunschweig38106Germany
- Helmholtz Centre for Infection ResearchAG NINDInhoffenstr. 7Braunschweig38124Germany
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30
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Monday HR, Younts TJ, Castillo PE. Long-Term Plasticity of Neurotransmitter Release: Emerging Mechanisms and Contributions to Brain Function and Disease. Annu Rev Neurosci 2018; 41:299-322. [PMID: 29709205 DOI: 10.1146/annurev-neuro-080317-062155] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Long-lasting changes of brain function in response to experience rely on diverse forms of activity-dependent synaptic plasticity. Chief among them are long-term potentiation and long-term depression of neurotransmitter release, which are widely expressed by excitatory and inhibitory synapses throughout the central nervous system and can dynamically regulate information flow in neural circuits. This review article explores recent advances in presynaptic long-term plasticity mechanisms and contributions to circuit function. Growing evidence indicates that presynaptic plasticity may involve structural changes, presynaptic protein synthesis, and transsynaptic signaling. Presynaptic long-term plasticity can alter the short-term dynamics of neurotransmitter release, thereby contributing to circuit computations such as novelty detection, modifications of the excitatory/inhibitory balance, and sensory adaptation. In addition, presynaptic long-term plasticity underlies forms of learning and its dysregulation participates in several neuropsychiatric conditions, including schizophrenia, autism, intellectual disabilities, neurodegenerative diseases, and drug abuse.
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Affiliation(s)
- Hannah R Monday
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA;
| | - Thomas J Younts
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA;
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31
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Shinoda Y, Sadakata T, Akagi T, Sakamaki Y, Hashikawa T, Sano Y, Furuichi T. Calcium-dependent activator protein for secretion 2 (CADPS2) deficiency causes abnormal synapse development in hippocampal mossy fiber terminals. Neurosci Lett 2018; 677:65-71. [PMID: 29689341 DOI: 10.1016/j.neulet.2018.04.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/06/2018] [Accepted: 04/18/2018] [Indexed: 12/27/2022]
Abstract
Hippocampal mossy fibers (MFs) project from dentate gyrus granule cells onto the CA2-CA3 region. MF-mediated synaptic transmission plays an important role in hippocampal learning and memory. However, the molecular mechanisms underlying MF synaptic development and subsequent functional organization are not fully understood. We previously reported that calcium-dependent activator protein for secretion 2 (CADPS2, also known as CAPS2) regulates the secretion of dense-core vesicles (DCVs). Because CADPS2 is strongly expressed in MF terminals, we hypothesized that CADPS2 regulates the development and functional organization of MF synapses by controlling the secretion of DCVs and their contents. To test this, we compared the synaptic microstructures of hippocampal MF terminals in Cadps2 knockout (KO) mice and wild-type (WT) mice by electron microscopy (EM). On postnatal day 15 (P15), KO mice exhibited morphological abnormalities in MF boutons, including smaller bouton size, a larger number of DCVs and a smaller number of post-synaptic densities (PSDs), compared with WT mice. In adults (P56), MF boutons were larger in KO mice. Synaptic vesicles (SVs) were increased but with a lower density compared with the WT. Furthermore, the number of SVs was decreased near the active zone. Moreover, MF-innervated CA3 postsynapses in KO mice displayed aberrant structures at the postsynaptic density (PSD), with an increased number of PSDs (likely because of a larger number of perforated PSDs), compared with WT mice. Taken together, our findings suggest that CADPS2 plays a critical role in MF synaptic development and functional organization.
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Affiliation(s)
- Yo Shinoda
- Department of Environmental Health, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan; Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan; Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan.
| | - Tetsushi Sadakata
- Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan; Education and Research Support Center, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan
| | - Takumi Akagi
- Research Resource Center, RIKEN Brain Science Institute, Wako, Saitama 351-0106, Japan; Department of Physiology, Nippon Medical School, Bunkyo-ku, Tokyo 113-8602, Japan
| | - Yuriko Sakamaki
- Research Resource Center, RIKEN Brain Science Institute, Wako, Saitama 351-0106, Japan; Research Core, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8510, Japan
| | - Tsutomu Hashikawa
- Research Resource Center, RIKEN Brain Science Institute, Wako, Saitama 351-0106, Japan; Laboratory for Molecular Mechanisms of Thalamus Development, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Yoshitake Sano
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan
| | - Teiichi Furuichi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan; Laboratory for Molecular Neurogenesis, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan.
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32
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Single Bursts of Individual Granule Cells Functionally Rearrange Feedforward Inhibition. J Neurosci 2018; 38:1711-1724. [PMID: 29335356 PMCID: PMC5815453 DOI: 10.1523/jneurosci.1595-17.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 12/07/2017] [Accepted: 01/05/2018] [Indexed: 12/15/2022] Open
Abstract
The sparse single-spike activity of dentate gyrus granule cells (DG GCs) is punctuated by occasional brief bursts of 3–7 action potentials. It is well-known that such presynaptic bursts in individual mossy fibers (MFs; axons of granule cells) are often able to discharge postsynaptic CA3 pyramidal cells due to powerful short-term facilitation. However, what happens in the CA3 network after the passage of a brief MF burst, before the arrival of the next burst or solitary spike, is not understood. Because MFs innervate significantly more CA3 interneurons than pyramidal cells, we focused on unitary MF responses in identified interneurons in the seconds-long postburst period, using paired recordings in rat hippocampal slices. Single bursts as short as 5 spikes in <30 ms in individual presynaptic MFs caused a sustained, large increase (tripling) in the amplitude of the unitary MF-EPSCs for several seconds in ivy, axo-axonic/chandelier and basket interneurons. The postburst unitary MF-EPSCs in these feedforward interneurons reached amplitudes that were even larger than the MF-EPSCs during the bursts in the same cells. In contrast, no comparable postburst enhancement of MF-EPSCs could be observed in pyramidal cells or nonfeedforward interneurons. The robust postburst increase in MF-EPSCs in feedforward interneurons was associated with significant shortening of the unitary synaptic delay and large downstream increases in disynaptic IPSCs in pyramidal cells. These results reveal a new cell type-specific plasticity that enables even solitary brief bursts in single GCs to powerfully enhance inhibition at the DG-CA3 interface in the seconds-long time-scales of interburst intervals. SIGNIFICANCE STATEMENT The hippocampal formation is a brain region that plays key roles in spatial navigation and learning and memory. The first stage of information processing occurs in the dentate gyrus, where principal cells are remarkably quiet, discharging low-frequency single action potentials interspersed with occasional brief bursts of spikes. Such bursts, in particular, have attracted a lot of attention because they appear to be critical for efficient coding, storage, and recall of information. We show that single bursts of a few spikes in individual granule cells result in seconds-long potentiation of excitatory inputs to downstream interneurons. Thus, while it has been known that bursts powerfully discharge (“detonate”) hippocampal excitatory cells, this study clarifies that they also regulate inhibition during the interburst intervals.
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Control of Spike Transfer at Hippocampal Mossy Fiber Synapses In Vivo by GABAA and GABAB Receptor-Mediated Inhibition. J Neurosci 2017; 37:587-598. [PMID: 28100741 DOI: 10.1523/jneurosci.2057-16.2016] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 11/02/2016] [Accepted: 11/20/2016] [Indexed: 11/21/2022] Open
Abstract
Despite extensive studies in hippocampal slices and incentive from computational theories, the synaptic mechanisms underlying information transfer at mossy fiber (mf) connections between the dentate gyrus (DG) and CA3 neurons in vivo are still elusive. Here we used an optogenetic approach in mice to selectively target and control the activity of DG granule cells (GCs) while performing whole-cell and juxtacellular recordings of CA3 neurons in vivo In CA3 pyramidal cells (PCs), mf-CA3 synaptic responses consisted predominantly of an IPSP at low stimulation frequency (0.05 Hz). Upon increasing the frequency of stimulation, a biphasic response was observed consisting of a brief mf EPSP followed by an inhibitory response lasting on the order of 100 ms. Spike transfer at DG-CA3 interneurons recorded in the juxtacellular mode was efficient at low presynaptic stimulation frequency and appeared insensitive to an increased frequency of GC activity. Overall, this resulted in a robust and slow feedforward inhibition of spike transfer at mf-CA3 pyramidal cell synapses. Short-term plasticity of EPSPs with increasing frequency of presynaptic activity allowed inhibition to be overcome to reach spike discharge in CA3 PCs. Whereas the activation of GABAA receptors was responsible for the direct inhibition of light-evoked spike responses, the slow inhibition of spiking activity required the activation of GABAB receptors in CA3 PCs. The slow inhibitory response defined an optimum frequency of presynaptic activity for spike transfer at ∼10 Hz. Altogether these properties define the temporal rules for efficient information transfer at DG-CA3 synaptic connections in the intact circuit. SIGNIFICANCE STATEMENT Activity-dependent changes in synaptic strength constitute a basic mechanism for memory. Synapses from the dentate gyrus (DG) to the CA3 area of the hippocampus are distinctive for their prominent short-term plasticity, as studied in slices. Plasticity of DG-CA3 connections may assist in the encoding of precise memory in the CA3 network. Here we characterize DG-CA3 synaptic transmission in vivo using targeted optogenetic activation of DG granule cells while recording in whole-cell patch-clamp and juxtacellular configuration from CA3 pyramidal cells and interneurons. We show that, in vivo, short-term plasticity of excitatory inputs to CA3 pyramidal cells combines with robust feedforward inhibition mediated by both GABAA and GABAB receptors to control the efficacy and temporal rules for information transfer at DG-CA3 connections.
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34
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Okuda K, Kobayashi S, Fukaya M, Watanabe A, Murakami T, Hagiwara M, Sato T, Ueno H, Ogonuki N, Komano-Inoue S, Manabe H, Yamaguchi M, Ogura A, Asahara H, Sakagami H, Mizuguchi M, Manabe T, Tanaka T. CDKL5 controls postsynaptic localization of GluN2B-containing NMDA receptors in the hippocampus and regulates seizure susceptibility. Neurobiol Dis 2017; 106:158-170. [PMID: 28688852 DOI: 10.1016/j.nbd.2017.07.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/10/2017] [Accepted: 07/02/2017] [Indexed: 12/21/2022] Open
Abstract
Mutations in the Cyclin-dependent kinase-like 5 (CDKL5) gene cause severe neurodevelopmental disorders accompanied by intractable epilepsies, i.e. West syndrome or atypical Rett syndrome. Here we report generation of the Cdkl5 knockout mouse and show that CDKL5 controls postsynaptic localization of GluN2B-containing N-methyl-d-aspartate (NMDA) receptors in the hippocampus and regulates seizure susceptibility. Cdkl5 -/Y mice showed normal sensitivity to kainic acid; however, they displayed significant hyperexcitability to NMDA. In concordance with this result, electrophysiological analysis in the hippocampal CA1 region disclosed an increased ratio of NMDA/α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor-mediated excitatory postsynaptic currents (EPSCs) and a significantly larger decay time constant of NMDA receptor-mediated EPSCs (NMDA-EPSCs) as well as a stronger inhibition of the NMDA-EPSCs by the GluN2B-selective antagonist ifenprodil in Cdkl5 -/Y mice. Subcellular fractionation of the hippocampus from Cdkl5 -/Y mice revealed a significant increase of GluN2B and SAP102 in the PSD (postsynaptic density)-1T fraction, without changes in the S1 (post-nuclear) fraction or mRNA transcripts, indicating an intracellular distribution shift of these proteins to the PSD. Immunoelectron microscopic analysis of the hippocampal CA1 region further confirmed postsynaptic overaccumulation of GluN2B and SAP102 in Cdkl5 -/Y mice. Furthermore, ifenprodil abrogated the NMDA-induced hyperexcitability in Cdkl5 -/Y mice, suggesting that upregulation of GluN2B accounts for the enhanced seizure susceptibility. These data indicate that CDKL5 plays an important role in controlling postsynaptic localization of the GluN2B-SAP102 complex in the hippocampus and thereby regulates seizure susceptibility, and that aberrant NMDA receptor-mediated synaptic transmission underlies the pathological mechanisms of the CDKL5 loss-of-function.
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Affiliation(s)
- Kosuke Okuda
- Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shizuka Kobayashi
- Division of Neuronal Network, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Masahiro Fukaya
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara 252-0374, Japan
| | - Aya Watanabe
- Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Takuto Murakami
- Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Mai Hagiwara
- Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Tempei Sato
- Department of Systems Biomedicine, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan
| | - Hiroe Ueno
- Department of Systems Biomedicine, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan
| | - Narumi Ogonuki
- Bioresource Engineering Division, RIKEN BioResource Center, Tsukuba 305-0074, Japan
| | - Sayaka Komano-Inoue
- Department of Physiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Hiroyuki Manabe
- Department of Physiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Masahiro Yamaguchi
- Department of Physiology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Atsuo Ogura
- Bioresource Engineering Division, RIKEN BioResource Center, Tsukuba 305-0074, Japan
| | - Hiroshi Asahara
- Department of Systems Biomedicine, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan; Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla 92037, USA
| | - Hiroyuki Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara 252-0374, Japan
| | - Masashi Mizuguchi
- Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Toshiya Manabe
- Division of Neuronal Network, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Teruyuki Tanaka
- Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan.
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Rebola N, Carta M, Mulle C. Operation and plasticity of hippocampal CA3 circuits: implications for memory encoding. Nat Rev Neurosci 2017; 18:208-220. [DOI: 10.1038/nrn.2017.10] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Juárez-Muñoz Y, Rivera-Olvera A, Ramos-Languren LE, Escobar ML. CaMKII requirement for the persistence of in vivo hippocampal mossy fiber synaptic plasticity and structural reorganization. Neurobiol Learn Mem 2017; 139:56-62. [DOI: 10.1016/j.nlm.2016.12.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 11/25/2016] [Accepted: 12/23/2016] [Indexed: 10/20/2022]
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Shedding of neurexin 3β ectodomain by ADAM10 releases a soluble fragment that affects the development of newborn neurons. Sci Rep 2016; 6:39310. [PMID: 27991559 PMCID: PMC5171655 DOI: 10.1038/srep39310] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 11/22/2016] [Indexed: 01/08/2023] Open
Abstract
Neurexins are transmembrane synaptic cell adhesion molecules involved in the development and maturation of neuronal synapses. In the present study, we report that Nrxn3β is processed by the metalloproteases ADAM10, ADAM17, and by the intramembrane-cleaving protease γ-secretase, producing secreted neurexin3β (sNrxn3β) and a single intracellular domain (Nrxn3β-ICD). We further completed the full characterization of the sites at which Nrxn3β is processed by these proteases. Supporting the physiological relevance of the Nrxn3β processing, we demonstrate in vivo a significant effect of the secreted shedding product sNrxn3β on the morphological development of adult newborn neurons in the mouse hippocampus. We show that sNrxn3β produced by the cells of the dentate gyrus increases the spine density of newborn neurons whereas sNrxn3β produced by the newborn neuron itself affects the number of its mossy fiber terminal extensions. These results support a pivotal role of sNrxn3β in plasticity and network remodeling during neuronal development.
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Villanueva-Castillo C, Tecuatl C, Herrera-López G, Galván EJ. Aging-related impairments of hippocampal mossy fibers synapses on CA3 pyramidal cells. Neurobiol Aging 2016; 49:119-137. [PMID: 27794263 DOI: 10.1016/j.neurobiolaging.2016.09.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 09/15/2016] [Accepted: 09/17/2016] [Indexed: 11/16/2022]
Abstract
The network interaction between the dentate gyrus and area CA3 of the hippocampus is responsible for pattern separation, a process that underlies the formation of new memories, and which is naturally diminished in the aged brain. At the cellular level, aging is accompanied by a progression of biochemical modifications that ultimately affects its ability to generate and consolidate long-term potentiation. Although the synapse between dentate gyrus via the mossy fibers (MFs) onto CA3 neurons has been subject of extensive studies, the question of how aging affects the MF-CA3 synapse is still unsolved. Extracellular and whole-cell recordings from acute hippocampal slices of aged Wistar rats (34 ± 2 months old) show that aging is accompanied by a reduction in the interneuron-mediated inhibitory mechanisms of area CA3. Several MF-mediated forms of short-term plasticity, MF long-term potentiation and at least one of the critical signaling cascades necessary for potentiation are also compromised in the aged brain. An analysis of the spontaneous glutamatergic and gamma-aminobutyric acid-mediated currents on CA3 cells reveal a dramatic alteration in amplitude and frequency of the nonevoked events. CA3 cells also exhibited increased intrinsic excitability. Together, these results demonstrate that aging is accompanied by a decrease in the GABAergic inhibition, reduced expression of short- and long-term forms of synaptic plasticity, and increased intrinsic excitability.
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Affiliation(s)
| | - Carolina Tecuatl
- Departamento de Farmacobiología, Cinvestav Sede Sur, México City, México
| | | | - Emilio J Galván
- Departamento de Farmacobiología, Cinvestav Sede Sur, México City, México.
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Corvino V, Di Maria V, Marchese E, Lattanzi W, Biamonte F, Michetti F, Geloso MC. Estrogen administration modulates hippocampal GABAergic subpopulations in the hippocampus of trimethyltin-treated rats. Front Cell Neurosci 2015; 9:433. [PMID: 26594149 PMCID: PMC4633568 DOI: 10.3389/fncel.2015.00433] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 10/15/2015] [Indexed: 12/13/2022] Open
Abstract
Given the well-documented involvement of estrogens in the modulation of hippocampal functions in both physiological and pathological conditions, the present study investigates the effects of 17-beta estradiol (E2) administration in the rat model of hippocampal neurodegeneration induced by trimethyltin (TMT) administration (8 mg/kg), characterized by loss of pyramidal neurons in CA1, CA3/hilus hippocampal subfields, associated with astroglial and microglial activation, seizures and cognitive impairment. After TMT/saline treatment, ovariectomized animals received two doses of E2 (0.2 mg/kg intra-peritoneal) or vehicle, and were sacrificed 48 h or 7 days after TMT-treatment. Our results indicate that in TMT-treated animals E2 administration induces the early (48 h) upregulation of genes involved in neuroprotection and synaptogenesis, namely Bcl2, trkB, cadherin 2 and cyclin-dependent-kinase-5. Increased expression levels of glutamic acid decarboxylase (gad) 67, neuropeptide Y (Npy), parvalbumin, Pgc-1α and Sirtuin 1 genes, the latter involved in parvalbumin (PV) synthesis, were also evident. Unbiased stereology performed on rats sacrificed 7 days after TMT treatment showed that although E2 does not significantly influence the extent of TMT-induced neuronal death, significantly enhances the TMT-induced modulation of GABAergic interneuron population size in selected hippocampal subfields. In particular, E2 administration causes, in TMT-treated rats, a significant increase in the number of GAD67-expressing interneurons in CA1 stratum oriens, CA3 pyramidal layer, hilus and dentate gyrus, accompanied by a parallel increase in NPY-expressing cells, essentially in the same regions, and of PV-positive cells in CA1 pyramidal layer. The present results add information concerning the role of in vivo E2 administration on mechanisms involved in cellular plasticity in the adult brain.
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Affiliation(s)
- Valentina Corvino
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro Cuore Rome, Italy
| | - Valentina Di Maria
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro Cuore Rome, Italy
| | - Elisa Marchese
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro Cuore Rome, Italy
| | - Wanda Lattanzi
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro Cuore Rome, Italy
| | - Filippo Biamonte
- Institute of Histology and Embryology, Università Cattolica del Sacro Cuore Rome, Italy
| | - Fabrizio Michetti
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro Cuore Rome, Italy
| | - Maria Concetta Geloso
- Institute of Anatomy and Cell Biology, Università Cattolica del Sacro Cuore Rome, Italy
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Wiera G, Mozrzymas JW. Extracellular proteolysis in structural and functional plasticity of mossy fiber synapses in hippocampus. Front Cell Neurosci 2015; 9:427. [PMID: 26582976 PMCID: PMC4631828 DOI: 10.3389/fncel.2015.00427] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/09/2015] [Indexed: 02/04/2023] Open
Abstract
Brain is continuously altered in response to experience and environmental changes. One of the underlying mechanisms is synaptic plasticity, which is manifested by modification of synapse structure and function. It is becoming clear that regulated extracellular proteolysis plays a pivotal role in the structural and functional remodeling of synapses during brain development, learning and memory formation. Clearly, plasticity mechanisms may substantially differ between projections. Mossy fiber synapses onto CA3 pyramidal cells display several unique functional features, including pronounced short-term facilitation, a presynaptically expressed long-term potentiation (LTP) that is independent of NMDAR activation, and NMDA-dependent metaplasticity. Moreover, structural plasticity at mossy fiber synapses ranges from the reorganization of projection topology after hippocampus-dependent learning, through intrinsically different dynamic properties of synaptic boutons to pre- and postsynaptic structural changes accompanying LTP induction. Although concomitant functional and structural plasticity in this pathway strongly suggests a role of extracellular proteolysis, its impact only starts to be investigated in this projection. In the present report, we review the role of extracellular proteolysis in various aspects of synaptic plasticity in hippocampal mossy fiber synapses. A growing body of evidence demonstrates that among perisynaptic proteases, tissue plasminogen activator (tPA)/plasmin system, β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) and metalloproteinases play a crucial role in shaping plastic changes in this projection. We discuss recent advances and emerging hypotheses on the roles of proteases in mechanisms underlying mossy fiber target specific synaptic plasticity and memory formation.
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Affiliation(s)
- Grzegorz Wiera
- Department of Animal Molecular Physiology, Institute of Experimental Biology, Wroclaw University Wroclaw, Poland ; Laboratory of Neuroscience, Department of Biophysics, Wroclaw Medical University Wroclaw, Poland
| | - Jerzy W Mozrzymas
- Department of Animal Molecular Physiology, Institute of Experimental Biology, Wroclaw University Wroclaw, Poland ; Laboratory of Neuroscience, Department of Biophysics, Wroclaw Medical University Wroclaw, Poland
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Dieni S, Nestel S, Sibbe M, Frotscher M, Hellwig S. Distinct synaptic and neurochemical changes to the granule cell-CA3 projection in Bassoon mutant mice. Front Synaptic Neurosci 2015; 7:18. [PMID: 26557085 PMCID: PMC4615824 DOI: 10.3389/fnsyn.2015.00018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/05/2015] [Indexed: 01/19/2023] Open
Abstract
Proper synaptic function depends on a finely-tuned balance between events such as protein synthesis and structural organization. In particular, the functional loss of just one synaptic-related protein can have a profound impact on overall neuronal network function. To this end, we used a mutant mouse model harboring a mutated form of the presynaptic scaffolding protein Bassoon (Bsn), which is phenotypically characterized by: (i) spontaneous generalized epileptic seizure activity, representing a chronically-imbalanced neuronal network; and (ii) a dramatic increase in hippocampal brain-derived neurotrophic factor (BDNF) protein concentration, a key player in synaptic plasticity. Detailed morphological and neurochemical analyses revealed that the increased BDNF levels are associated with: (i) modified neuropeptide distribution; (ii) perturbed expression of selected markers of synaptic activation or plasticity; (iii) subtle changes to microglial structure; and (iv) morphological alterations to the mossy fiber (MF) synapse. These findings emphasize the important contribution of Bassoon protein to normal hippocampal function, and further characterize the Bsn-mutant as a useful model for studying the effects of chronic changes to network activity.
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Affiliation(s)
- Sandra Dieni
- Neurochemistry Laboratory, Department of Molecular Psychiatry, University Hospital Freiburg Freiburg, Germany
| | - Sigrun Nestel
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, University of Freiburg Freiburg, Germany
| | - Mirjam Sibbe
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, University of Freiburg Freiburg, Germany
| | - Michael Frotscher
- Institute for Structural Neurobiology, Center for Molecular Neurobiology Hamburg Hamburg, Germany
| | - Sabine Hellwig
- Neurochemistry Laboratory, Department of Molecular Psychiatry, University Hospital Freiburg Freiburg, Germany
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Keller MK, Draguhn A, Both M, Reichinnek S. Activity-dependent plasticity of mouse hippocampal assemblies in vitro. Front Neural Circuits 2015; 9:21. [PMID: 26041998 PMCID: PMC4435105 DOI: 10.3389/fncir.2015.00021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 04/27/2015] [Indexed: 11/13/2022] Open
Abstract
Memory formation is associated with the generation of transiently stable neuronal assemblies. In hippocampal networks, such groups of functionally coupled neurons express highly ordered spatiotemporal activity patterns which are coordinated by local network oscillations. One of these patterns, sharp wave-ripple complexes (SPW-R), repetitively activates previously established groups of memory-encoding neurons, thereby supporting memory consolidation. This function implies that repetition of specific SPW-R induces plastic changes which render the underlying neuronal assemblies more stable. We modeled this repetitive activation in an in vitro model of SPW-R in mouse hippocampal slices. Weak electrical stimulation upstream of the CA3-CA1 networks reliably induced SPW-R of stereotypic waveform, thus representing re-activation of similar neuronal activity patterns. Frequent repetition of these patterns (100 times) reduced the variance of both, evoked and spontaneous SPW-R waveforms, indicating stabilization of pre-existing assemblies. These effects were most pronounced in the CA1 subfield and depended on the timing of stimulation relative to spontaneous SPW-R. Additionally, plasticity of SPW-R was blocked by application of a NMDA receptor antagonist, suggesting a role for associative synaptic plasticity in this process. Thus, repetitive activation of specific patterns of SPW-R causes stabilization of memory-related networks.
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Affiliation(s)
- Martin K Keller
- Institute of Physiology and Pathophysiology, University of Heidelberg Heidelberg, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, University of Heidelberg Heidelberg, Germany
| | - Martin Both
- Institute of Physiology and Pathophysiology, University of Heidelberg Heidelberg, Germany
| | - Susanne Reichinnek
- Institute of Physiology and Pathophysiology, University of Heidelberg Heidelberg, Germany ; Mediterranean Institute of Neurobiology (INMED), INSERM Marseille, France
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Cherubini E, Miles R. The CA3 region of the hippocampus: how is it? What is it for? How does it do it? Front Cell Neurosci 2015; 9:19. [PMID: 25698930 PMCID: PMC4318343 DOI: 10.3389/fncel.2015.00019] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 01/12/2015] [Indexed: 11/13/2022] Open
Affiliation(s)
- Enrico Cherubini
- Department of Neuroscience, International School for Advanced Studies Trieste, Italy ; European Brain Research Institute (EBRI) Rita Levi-Montalcini Rome, Italy
| | - Richard Miles
- Institut du Cerveau et de la Moelle, CHU Pitié-Salpêtrière Inserm U1127, CNRS UMR7225, Université Pierre et Marie Curie UMR S1127 Paris, France
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Deppermann S, Storchak H, Fallgatter A, Ehlis AC. Stress-induced neuroplasticity: (Mal)adaptation to adverse life events in patients with PTSD – A critical overview. Neuroscience 2014; 283:166-77. [DOI: 10.1016/j.neuroscience.2014.08.037] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 08/21/2014] [Accepted: 08/23/2014] [Indexed: 10/24/2022]
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Perin M, Longordo F, Massonnet C, Welker E, Lüthi A. Diurnal inhibition of NMDA-EPSCs at rat hippocampal mossy fibre synapses through orexin-2 receptors. J Physiol 2014; 592:4277-95. [PMID: 25085886 DOI: 10.1113/jphysiol.2014.272757] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Diurnal release of the orexin neuropeptides orexin-A (Ox-A, hypocretin-1) and orexin-B (Ox-B, hypocretin-2) stabilises arousal, regulates energy homeostasis and contributes to cognition and learning. However, whether cellular correlates of brain plasticity are regulated through orexins, and whether they do so in a time-of-day-dependent manner, has never been assessed. Immunohistochemically we found sparse but widespread innervation of hippocampal subfields through Ox-A- and Ox-B-containing fibres in young adult rats. The actions of Ox-A were studied on NMDA receptor (NMDAR)-mediated excitatory synaptic transmission in acute hippocampal slices prepared around the trough (Zeitgeber time (ZT) 4-8, corresponding to 4-8 h into the resting phase) and peak (ZT 23) of intracerebroventricular orexin levels. At ZT 4-8, exogenous Ox-A (100 nm in bath) inhibited NMDA receptor-mediated excitatory postsynaptic currents (NMDA-EPSCs) at mossy fibre (MF)-CA3 (to 55.6 ± 6.8% of control, P = 0.0003) and at Schaffer collateral-CA1 synapses (70.8 ± 6.3%, P = 0.013), whereas it remained ineffective at non-MF excitatory synapses in CA3. Ox-A actions were mediated postsynaptically and blocked by the orexin-2 receptor (OX2R) antagonist JNJ10397049 (1 μm), but not by orexin-1 receptor inhibition (SB334867, 1 μm) or by adrenergic and cholinergic antagonists. At ZT 23, inhibitory effects of exogenous Ox-A were absent (97.6 ± 2.9%, P = 0.42), but reinstated (87.2 ± 3.3%, P = 0.002) when endogenous orexin signalling was attenuated for 5 h through i.p. injections of almorexant (100 mg kg(-1)), a dual orexin receptor antagonist. In conclusion, endogenous orexins modulate hippocampal NMDAR function in a time-of-day-dependent manner, suggesting that they may influence cellular plasticity and consequent variations in memory performance across the sleep-wake cycle.
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Affiliation(s)
- Martina Perin
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, CH-1005, Lausanne, Switzerland
| | - Fabio Longordo
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, CH-1005, Lausanne, Switzerland
| | - Christine Massonnet
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, CH-1005, Lausanne, Switzerland
| | - Egbert Welker
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, CH-1005, Lausanne, Switzerland
| | - Anita Lüthi
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, CH-1005, Lausanne, Switzerland
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