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Bosson A, Paumier A, Boisseau S, Jacquier-Sarlin M, Buisson A, Albrieux M. TRPA1 channels promote astrocytic Ca 2+ hyperactivity and synaptic dysfunction mediated by oligomeric forms of amyloid-β peptide. Mol Neurodegener 2017; 12:53. [PMID: 28683776 PMCID: PMC5501536 DOI: 10.1186/s13024-017-0194-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/29/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Excessive synaptic loss is thought to be one of the earliest events in Alzheimer's disease (AD). However, the key mechanisms that maintain plasticity of synapses during adulthood or initiate synapse dysfunction in AD remain unknown. Recent studies suggest that astrocytes contribute to functional changes observed during synaptic plasticity and play a major role in synaptic dysfunction but astrocytes behavior and involvement in early phases of AD remained largely undefined. METHODS We measure astrocytic calcium activity in mouse CA1 hippocampus stratum radiatum in both the global astrocytic population and at a single cell level, focusing in the highly compartmentalized astrocytic arbor. Concurrently, we measure excitatory post-synaptic currents in nearby pyramidal neurons. RESULTS We find that application of soluble Aβ oligomers (Aβo) induced fast and widespread calcium hyperactivity in the astrocytic population and in the microdomains of the astrocyte arbor. We show that astrocyte hyperactivity is independent of neuronal activity and is repaired by transient receptor potential A1 (TRPA1) channels blockade. In return, this TRPA1 channels-dependent hyperactivity influences neighboring CA1 neurons triggering an increase in glutamatergic spontaneous activity. Interestingly, in an AD mouse model (APP/PS1-21 mouse), astrocyte calcium hyperactivity equally takes place at the beginning of Aβ production, depends on TRPA1 channels and is linked to CA1 neurons hyperactivity. CONCLUSIONS Our experiments demonstrate that astrocytes contribute to early Aβo toxicity exhibiting a global and local Ca2+ hyperactivity that involves TRPA1 channels and is related to neuronal hyperactivity. Together, our data suggest that astrocyte is a frontline target of Aβo and highlight a novel mechanism for the understanding of early synaptic dysregulation induced by soluble Aβo species.
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Affiliation(s)
- Anthony Bosson
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
| | - Adrien Paumier
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
| | - Sylvie Boisseau
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
| | - Muriel Jacquier-Sarlin
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
| | - Alain Buisson
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
| | - Mireille Albrieux
- University Grenoble Alpes, Grenoble Institut des Neurosciences, GIN, Chemin Fortuné Ferrini, BP170, F-38000 Grenoble, France
- Inserm, U1216, F-38000 Grenoble, France
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152
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Huguet G, Joglekar A, Messi LM, Buckalew R, Wong S, Terman D. Neuroprotective Role of Gap Junctions in a Neuron Astrocyte Network Model. Biophys J 2017; 111:452-462. [PMID: 27463146 DOI: 10.1016/j.bpj.2016.05.051] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/23/2016] [Accepted: 05/31/2016] [Indexed: 12/27/2022] Open
Abstract
A detailed biophysical model for a neuron/astrocyte network is developed to explore mechanisms responsible for the initiation and propagation of cortical spreading depolarizations and the role of astrocytes in maintaining ion homeostasis, thereby preventing these pathological waves. Simulations of the model illustrate how properties of spreading depolarizations, such as wave speed and duration of depolarization, depend on several factors, including the neuron and astrocyte Na(+)-K(+) ATPase pump strengths. In particular, we consider the neuroprotective role of astrocyte gap junction coupling. The model demonstrates that a syncytium of electrically coupled astrocytes can maintain a physiological membrane potential in the presence of an elevated extracellular K(+) concentration and efficiently distribute the excess K(+) across the syncytium. This provides an effective neuroprotective mechanism for delaying or preventing the initiation of spreading depolarizations.
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Affiliation(s)
- Gemma Huguet
- Department de Matematiques, Universitat Politecnica de Catalunya, Barcelona, Spain
| | | | | | - Richard Buckalew
- Mathematical Bioscience Institute, Ohio State University, Columbus, Ohio
| | - Sarah Wong
- Department of Mathematics, Ohio State University, Columbus, Ohio
| | - David Terman
- Department of Mathematics, Ohio State University, Columbus, Ohio.
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153
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Adamsky A, Goshen I. Astrocytes in Memory Function: Pioneering Findings and Future Directions. Neuroscience 2017; 370:14-26. [PMID: 28571720 DOI: 10.1016/j.neuroscience.2017.05.033] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/05/2017] [Accepted: 05/19/2017] [Indexed: 12/29/2022]
Abstract
Astrocytes have been generally believed to perform mainly homeostatic and supportive functions for neurons in the central nervous system. Recently, a growing body of evidence suggests previously unrecognized and surprising functions for astrocytes, including regulation of synaptic formation, transmission and plasticity, all of which are considered as the infrastructure for information processing and memory formation and stabilization. This review discusses the involvement of astrocytes in memory functions and the possible mechanisms that may underlie it. We review the important breakthroughs obtained in this field, as well as some of the controversies that arose from the past difficulty to manipulate these cells in a cell type-specific and non-invasive manner. Finally, we present new research avenues based on the advanced tools becoming available in recent years: optogenetics and chemogenetics, and the potential ways in which these tools may further illuminate the role of astrocytes in memory processes.
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Affiliation(s)
- Adar Adamsky
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Givat Ram, Jerusalem 91904, Israel
| | - Inbal Goshen
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Givat Ram, Jerusalem 91904, Israel.
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154
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Lommen J, Stahr A, Ingenwerth M, Ali AAH, von Gall C. Time-of-day-dependent expression of purinergic receptors in mouse suprachiasmatic nucleus. Cell Tissue Res 2017; 369:579-590. [PMID: 28547658 PMCID: PMC5579179 DOI: 10.1007/s00441-017-2634-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 04/26/2017] [Indexed: 12/22/2022]
Abstract
Purinergic P2X and P2Y receptors are involved in mediating intercellular signalling via purines such as adenosine triphosphate (ATP). P2X and P2Y receptors have been implicated in numerous body functions including learning, memory and sleep. All of these body functions show time-of–day-dependent variations controlled by the master circadian oscillator located in the suprachiasmatic nucleus (SCN). Evidence exists for a role of purinergic signalling in intercellular coupling within SCN. However, few studies have been performed on the expression of purinergic receptors in SCN. Therefore, we analyse the expression of seven P2X (P2X1–7) and eight P2Y (P2Y1–2, 4, 6, 11–14) receptors in mouse SCN and address their time-of-day-dependent variation by using immunohistochemistry and real-time polymerase chain reaction. At the early light phase, P2X and P2Y receptors show a low to moderate, homogenously distributed immunoreaction throughout SCN. P2Y13 reveals strong immunoreaction in fibres within the core region of SCN. From the fifteen analysed P2 receptors, seven exhibit a time-of-day-dependent variation in SCN. P2X1 immunoreaction is very low in the early light phase with a minor increase at the end of the dark phase. P2X4 immunoreaction strongly increases during the dark phase in soma cells in the core region and in a dense network of fibres in the shell region of SCN. P2X3 immunoreaction is moderately elevated during the dark phase. Conversely, immunoreaction for P2Y2, P2Y12 and P2Y14 moderately increases at the early light phase and P2Y6 immunoreaction displays a moderate increase at the mid-light phase. Thus, this study demonstrates a time-of-day-dependent variation of P2 receptors in mouse SCN.
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Affiliation(s)
- Julian Lommen
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225, Düsseldorf, Germany
| | - Anna Stahr
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225, Düsseldorf, Germany
| | - Marc Ingenwerth
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225, Düsseldorf, Germany.,Institute of Pathology, University of Duisburg-Essen, University Hospital Essen, Hufelandstrasse 55, 45147, Essen, Germany
| | - Amira A H Ali
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225, Düsseldorf, Germany
| | - Charlotte von Gall
- Institute of Anatomy II, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225, Düsseldorf, Germany.
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155
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Allain F, Roberts DC, Lévesque D, Samaha AN. Intermittent intake of rapid cocaine injections promotes robust psychomotor sensitization, increased incentive motivation for the drug and mGlu2/3 receptor dysregulation. Neuropharmacology 2017; 117:227-237. [DOI: 10.1016/j.neuropharm.2017.01.026] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 12/15/2016] [Accepted: 01/25/2017] [Indexed: 02/03/2023]
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156
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Aleksin SG, Zheng K, Rusakov DA, Savtchenko LP. ARACHNE: A neural-neuroglial network builder with remotely controlled parallel computing. PLoS Comput Biol 2017; 13:e1005467. [PMID: 28362877 PMCID: PMC5393895 DOI: 10.1371/journal.pcbi.1005467] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 04/17/2017] [Accepted: 03/20/2017] [Indexed: 11/30/2022] Open
Abstract
Creating and running realistic models of neural networks has hitherto been a task for computing professionals rather than experimental neuroscientists. This is mainly because such networks usually engage substantial computational resources, the handling of which requires specific programing skills. Here we put forward a newly developed simulation environment ARACHNE: it enables an investigator to build and explore cellular networks of arbitrary biophysical and architectural complexity using the logic of NEURON and a simple interface on a local computer or a mobile device. The interface can control, through the internet, an optimized computational kernel installed on a remote computer cluster. ARACHNE can combine neuronal (wired) and astroglial (extracellular volume-transmission driven) network types and adopt realistic cell models from the NEURON library. The program and documentation (current version) are available at GitHub repository https://github.com/LeonidSavtchenko/Arachne under the MIT License (MIT).
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Affiliation(s)
- Sergey G. Aleksin
- AMC Bridge LLC, Waltham MA, United States of America and Dnipro, Ukraine
| | - Kaiyu Zheng
- UCL Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
| | - Dmitri A. Rusakov
- UCL Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
- * E-mail: (LPS); (DAR)
| | - Leonid P. Savtchenko
- UCL Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
- Institute of Neuroscience, University of Nizhny Novgorod, Nizhny Novgorod, Russia
- * E-mail: (LPS); (DAR)
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157
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Amar M, Singh A, Mallick BN. Noradrenergic β-Adrenoceptor-Mediated Intracellular Molecular Mechanism of Na-K ATPase Subunit Expression in C6 Cells. Cell Mol Neurobiol 2017; 38:441-457. [PMID: 28353187 DOI: 10.1007/s10571-017-0488-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/23/2017] [Indexed: 11/26/2022]
Abstract
Rapid eye movement sleep deprivation-associated elevated noradrenaline increases and decreases neuronal and glial Na-K ATPase activity, respectively. In this study, using C6 cell-line as a model, we investigated the possible intracellular molecular mechanism of noradrenaline-induced decreased glial Na-K ATPase activity. The cells were treated with noradrenaline in the presence or absence of adrenoceptor antagonists, modulators of extra- and intracellular Ca++ and modulators of intracellular signalling pathways. We observed that noradrenaline acting on β-adrenoceptor decreased Na-K ATPase activity and mRNA expression of the catalytic α2-Na-K ATPase subunit in the C6 cells. Further, cAMP and protein kinase-A mediated release of intracellular Ca++ played a critical role in such decreased α2-Na-K ATPase expression. In contrast, noradrenaline acting on β-adrenoceptor up-regulated the expression of regulatory β2-Na-K ATPase subunit, which although was cAMP and Ca++ dependent, was independent of protein kinase-A and protein kinase-C. Combining these with previous findings (including ours) we have proposed a working model for noradrenaline-induced suppression of glial Na-K ATPase activity and alteration in its subunit expression. The findings help understanding noradrenaline-associated maintenance of brain excitability during health and altered states, particularly in relation to rapid eye movement sleep and its deprivation when the noradrenaline level is naturally altered.
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Affiliation(s)
- Megha Amar
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Abhishek Singh
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
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158
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Mathematical investigation of IP 3-dependent calcium dynamics in astrocytes. J Comput Neurosci 2017; 42:257-273. [PMID: 28353176 DOI: 10.1007/s10827-017-0640-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 02/14/2017] [Accepted: 03/09/2017] [Indexed: 10/19/2022]
Abstract
We study evoked calcium dynamics in astrocytes, a major cell type in the mammalian brain. Experimental evidence has shown that such dynamics are highly variable between different trials, cells, and cell subcompartments. Here we present a qualitative analysis of a recent mathematical model of astrocyte calcium responses. We show how the major response types are generated in the model as a result of the underlying bifurcation structure. By varying key channel parameters, mimicking blockers used by experimentalists, we manipulate this underlying bifurcation structure and predict how the distributions of responses can change. We find that store-operated calcium channels, plasma membrane bound channels with little activity during calcium transients, have a surprisingly strong effect, underscoring the importance of considering these channels in both experiments and mathematical settings. Variation in the maximum flow in different calcium channels is also shown to determine the range of stable oscillations, as well as set the range of frequencies of the oscillations. Further, by conducting a randomized search through the parameter space and recording the resulting calcium responses, we create a database that can be used by experimentalists to help estimate the underlying channel distribution of their cells.
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159
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Haydon PG. Astrocytes and the modulation of sleep. Curr Opin Neurobiol 2017; 44:28-33. [PMID: 28284099 DOI: 10.1016/j.conb.2017.02.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 02/13/2017] [Indexed: 12/21/2022]
Abstract
Astrocytes are being identified as having multiple roles in sleep. Initially they were shown to modulate the process of sleep homeostasis through the release of adenosine which acts on adenosine A1 receptors (A1R) to promote sleep drive. More recent studies indicate that the astrocyte also plays pivotal, sleep-dependent roles in 'cleaning the brain' during sleep. This work indicates that a glymphatic pathway that critically relies on astrocytic aquaporin 4, is able to flush solutes from the brain and that deficits in this pathway may contribute to Alzheimer's disease. Finally, astrocytes are known to play important metabolic roles and provide energy on demand to neurons through an astrocyte-neuron shuttle. Given that the time course of astrocytic function is orders of magnitude slower than that of the neuron, this non-neuronal cell is perfectly tuned to modulating slow, state-dependent changes in the brain.
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Affiliation(s)
- Philip G Haydon
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA 02111, United States.
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160
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Frago LM, Chowen JA. Involvement of Astrocytes in Mediating the Central Effects of Ghrelin. Int J Mol Sci 2017; 18:ijms18030536. [PMID: 28257088 PMCID: PMC5372552 DOI: 10.3390/ijms18030536] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 02/16/2017] [Accepted: 02/25/2017] [Indexed: 12/31/2022] Open
Abstract
Although astrocytes are the most abundant cells in the mammalian brain, much remains to be learned about their molecular and functional features. Astrocytes express receptors for numerous hormones and metabolic factors, including the appetite-promoting hormone ghrelin. The metabolic effects of ghrelin are largely opposite to those of leptin, as it stimulates food intake and decreases energy expenditure. Ghrelin is also involved in glucose-sensing and glucose homeostasis. The widespread expression of the ghrelin receptor in the central nervous system suggests that this hormone is not only involved in metabolism, but also in other essential functions in the brain. In fact, ghrelin has been shown to promote cell survival and neuroprotection, with some studies exploring the use of ghrelin as a therapeutic agent against metabolic and neurodegenerative diseases. In this review, we highlight the possible role of glial cells as mediators of ghrelin's actions within the brain.
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Affiliation(s)
- Laura M Frago
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, 28009 Madrid, Spain.
- Department of Pediatrics, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
| | - Julie A Chowen
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación la Princesa, CIBER de Obesidad Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, 28009 Madrid, Spain.
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161
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Buscemi L, Ginet V, Lopatar J, Montana V, Pucci L, Spagnuolo P, Zehnder T, Grubišić V, Truttman A, Sala C, Hirt L, Parpura V, Puyal J, Bezzi P. Homer1 Scaffold Proteins Govern Ca2+ Dynamics in Normal and Reactive Astrocytes. Cereb Cortex 2017; 27:2365-2384. [PMID: 27075036 PMCID: PMC5963825 DOI: 10.1093/cercor/bhw078] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In astrocytes, the intracellular calcium (Ca2+) signaling mediated by activation of metabotropic glutamate receptor 5 (mGlu5) is crucially involved in the modulation of many aspects of brain physiology, including gliotransmission. Here, we find that the mGlu5-mediated Ca2+ signaling leading to release of glutamate is governed by mGlu5 interaction with Homer1 scaffolding proteins. We show that the long splice variants Homer1b/c are expressed in astrocytic processes, where they cluster with mGlu5 at sites displaying intense local Ca2+ activity. We show that the structural and functional significance of the Homer1b/c-mGlu5 interaction is to relocate endoplasmic reticulum (ER) to the proximity of the plasma membrane and to optimize Ca2+ signaling and glutamate release. We also show that in reactive astrocytes the short dominant-negative splice variant Homer1a is upregulated. Homer1a, by precluding the mGlu5-ER interaction decreases the intensity of Ca2+ signaling thus limiting the intensity and the duration of glutamate release by astrocytes. Hindering upregulation of Homer1a with a local injection of short interfering RNA in vivo restores mGlu5-mediated Ca2+ signaling and glutamate release and sensitizes astrocytes to apoptosis. We propose that Homer1a may represent one of the cellular mechanisms by which inflammatory astrocytic reactions are beneficial for limiting brain injury.
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Affiliation(s)
- Lara Buscemi
- Department of Fundamental Neurosciences, University of Lausanne, CH1005Lausanne, Switzerland
- Stroke Laboratory, Neurology Service, Department of Clinical Neurosciences, University Hospital Centre and University of Lausanne, CH-1011 Lausanne, Switzerland
| | - Vanessa Ginet
- Department of Fundamental Neurosciences, University of Lausanne, CH1005Lausanne, Switzerland
- Division of Neonatology, Department of Paediatrics and Paediatric Surgery, University Hospital Centre and University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Jan Lopatar
- Department of Fundamental Neurosciences, University of Lausanne, CH1005Lausanne, Switzerland
| | - Vedrana Montana
- Department of Biotechnology, University of Rijeka, 51000 Rijeka, Croatia
- Department of Neurobiology, Center for Glial Biology in Medicine, Civitan International Research Center, Atomic Force Microscopy and Nanotechnology Laboratories, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Luca Pucci
- Department of Fundamental Neurosciences, University of Lausanne, CH1005Lausanne, Switzerland
| | - Paola Spagnuolo
- Department of Fundamental Neurosciences, University of Lausanne, CH1005Lausanne, Switzerland
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy
| | - Tamara Zehnder
- Department of Fundamental Neurosciences, University of Lausanne, CH1005Lausanne, Switzerland
| | - Vladimir Grubišić
- Department of Neurobiology, Center for Glial Biology in Medicine, Civitan International Research Center, Atomic Force Microscopy and Nanotechnology Laboratories, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Anita Truttman
- Division of Neonatology, Department of Paediatrics and Paediatric Surgery, University Hospital Centre and University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Carlo Sala
- CNR Institute of Neuroscience and Department of Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Lorenz Hirt
- Stroke Laboratory, Neurology Service, Department of Clinical Neurosciences, University Hospital Centre and University of Lausanne, CH-1011 Lausanne, Switzerland
| | - Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine, Civitan International Research Center, Atomic Force Microscopy and Nanotechnology Laboratories, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Julien Puyal
- Department of Fundamental Neurosciences, University of Lausanne, CH1005Lausanne, Switzerland
- Division of Neonatology, Department of Paediatrics and Paediatric Surgery, University Hospital Centre and University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Paola Bezzi
- Department of Fundamental Neurosciences, University of Lausanne, CH1005Lausanne, Switzerland
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162
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Guo G, Peng Y, Xiong B, Liu D, Bu H, Tian X, Yang H, Wu Z, Cao F, Gao F. Involvement of chemokine CXCL11 in the development of morphine tolerance in rats with cancer-induced bone pain. J Neurochem 2017; 141:553-564. [PMID: 27926984 DOI: 10.1111/jnc.13919] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 11/14/2016] [Accepted: 11/18/2016] [Indexed: 01/26/2023]
Affiliation(s)
- Genhua Guo
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science & Technology; Wuhan China
- Department of Anesthesiology; The Central People's Hospital of Ji'an City; Ji'an China
| | - Yawen Peng
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science & Technology; Wuhan China
| | - Bingrui Xiong
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science & Technology; Wuhan China
| | - Daiqiang Liu
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science & Technology; Wuhan China
| | - Huilian Bu
- Department of Anesthesiology; The first affiliated hospital of Zhengzhou University; Zhengzhou China
| | - Xuebi Tian
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science & Technology; Wuhan China
| | - Hui Yang
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science & Technology; Wuhan China
| | - Zhen Wu
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science & Technology; Wuhan China
| | - Fei Cao
- Department of Psychiatry and Behavioral Science; UT Health Medical School; Houston Texas USA
| | - Feng Gao
- Department of Anesthesiology; Tongji Hospital; Tongji Medical College; Huazhong University of Science & Technology; Wuhan China
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163
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Astrocyte Sodium Signalling and Panglial Spread of Sodium Signals in Brain White Matter. Neurochem Res 2017; 42:2505-2518. [PMID: 28214986 DOI: 10.1007/s11064-017-2197-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 01/19/2017] [Accepted: 01/28/2017] [Indexed: 10/20/2022]
Abstract
In brain grey matter, excitatory synaptic transmission activates glutamate uptake into astrocytes, inducing sodium signals which propagate into neighboring astrocytes through gap junctions. These sodium signals have been suggested to serve an important role in neuro-metabolic coupling. So far, it is unknown if astrocytes in white matter-that is in brain regions devoid of synapses-are also able to undergo such intra- and intercellular sodium signalling. In the present study, we have addressed this question by performing quantitative sodium imaging in acute tissue slices of mouse corpus callosum. Focal application of glutamate induced sodium transients in SR101-positive astrocytes. These were largely unaltered in the presence of ionotropic glutamate receptors blockers, but strongly dampened upon pharmacological inhibition of glutamate uptake. Sodium signals induced in individual astrocytes readily spread into neighboring SR101-positive cells with peak amplitudes decaying monoexponentially with distance from the stimulated cell. In addition, spread of sodium was largely unaltered during pharmacological inhibition of purinergic and glutamate receptors, indicating gap junction-mediated, passive diffusion of sodium between astrocytes. Using cell-type-specific, transgenic reporter mice, we found that sodium signals also propagated, albeit less effectively, from astrocytes to neighboring oligodendrocytes and NG2 cells. Again, panglial spread was unaltered with purinergic and glutamate receptors blocked. Taken together, our results demonstrate that activation of sodium-dependent glutamate transporters induces sodium signals in white matter astrocytes, which spread within the astrocyte syncytium. In addition, we found a panglial passage of sodium signals from astrocytes to NG2 cells and oligodendrocytes, indicating functional coupling between these macroglial cells in white matter.
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164
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Heller JP, Michaluk P, Sugao K, Rusakov DA. Probing nano-organization of astroglia with multi-color super-resolution microscopy. J Neurosci Res 2017; 95:2159-2171. [PMID: 28151556 DOI: 10.1002/jnr.24026] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 12/12/2016] [Accepted: 12/28/2016] [Indexed: 01/04/2023]
Abstract
Astroglia are essential for brain development, homeostasis, and metabolic support. They also contribute actively to the formation and regulation of synaptic circuits, by successfully handling, integrating, and propagating physiological signals of neural networks. The latter occurs mainly by engaging a versatile mechanism of internal Ca2+ fluctuations and regenerative waves prompting targeted release of signaling molecules into the extracellular space. Astroglia also show substantial structural plasticity associated with age- and use-dependent changes in neural circuitry. However, the underlying cellular mechanisms are poorly understood, mainly because of the extraordinary complex morphology of astroglial compartments on the nanoscopic scale. This complexity largely prevents direct experimental access to astroglial processes, most of which are beyond the diffraction limit of optical microscopy. Here we employed super-resolution microscopy (direct stochastic optical reconstruction microscopy; dSTORM), to visualize astroglial organization on the nanoscale, in culture and in thin brain slices, as an initial step to understand the structural basis of astrocytic nano-physiology. We were able to follow nanoscopic morphology of GFAP-enriched astrocytes, which adapt a flattened shape in culture and a sponge-like structure in situ, with GFAP fibers of varied diameters. We also visualized nanoscopic astrocytic processes using the ubiquitous cytosolic astrocyte marker proteins S100β and glutamine synthetase. Finally, we overexpressed and imaged membrane-targeted pHluorin and lymphocyte-specific protein tyrosine kinase (N-terminal domain) -green fluorescent protein (lck-GFP), to better understand the molecular cascades underlying some common astroglia-targeted fluorescence imaging techniques. The results provide novel, albeit initial, insights into the cellular organization of astroglia on the nanoscale, paving the way for function-specific studies. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Janosch P Heller
- UCL Institute of Neurology, Department of Clinical and Experimental Epilepsy, Queen Square House, London WC1N 3BG, United Kingdom
| | - Piotr Michaluk
- UCL Institute of Neurology, Department of Clinical and Experimental Epilepsy, Queen Square House, London WC1N 3BG, United Kingdom
| | - Kohtaroh Sugao
- UCL Institute of Neurology, Department of Clinical and Experimental Epilepsy, Queen Square House, London WC1N 3BG, United Kingdom.,Molecular Pathophysiology Research, Drug Research Division, Sumitomo Dainippon Pharma Co., Ltd., Tokyo, 104-8356, Japan
| | - Dmitri A Rusakov
- UCL Institute of Neurology, Department of Clinical and Experimental Epilepsy, Queen Square House, London WC1N 3BG, United Kingdom
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165
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Chen R, Canales A, Anikeeva P. Neural Recording and Modulation Technologies. NATURE REVIEWS. MATERIALS 2017; 2:16093. [PMID: 31448131 PMCID: PMC6707077 DOI: 10.1038/natrevmats.2016.93] [Citation(s) in RCA: 289] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Within the mammalian nervous system, billions of neurons connected by quadrillions of synapses exchange electrical, chemical and mechanical signals. Disruptions to this network manifest as neurological or psychiatric conditions. Despite decades of neuroscience research, our ability to treat or even to understand these conditions is limited by the tools capable of probing the signalling complexity of the nervous system. Although orders of magnitude smaller and computationally faster than neurons, conventional substrate-bound electronics do not address the chemical and mechanical properties of neural tissue. This mismatch results in a foreign-body response and the encapsulation of devices by glial scars, suggesting that the design of an interface between the nervous system and a synthetic sensor requires additional materials innovation. Advances in genetic tools for manipulating neural activity have fuelled the demand for devices capable of simultaneous recording and controlling individual neurons at unprecedented scales. Recently, flexible organic electronics and bio- and nanomaterials have been developed for multifunctional and minimally invasive probes for long-term interaction with the nervous system. In this Review, we discuss the design lessons from the quarter-century-old field of neural engineering, highlight recent materials-driven progress in neural probes, and look at emergent directions inspired by the principles of neural transduction.
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Affiliation(s)
- Ritchie Chen
- Department of Materials Science and Engineering, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Andres Canales
- Department of Materials Science and Engineering, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Polina Anikeeva
- Department of Materials Science and Engineering, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
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166
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Shtrahman E, Maruyama D, Olariu E, Fink C, Zochowski M. Understanding spatial and temporal patterning of astrocyte calcium transients via interactions between network transport and extracellular diffusion. Phys Biol 2017; 14:016001. [PMID: 28004641 PMCID: PMC5333993 DOI: 10.1088/1478-3975/aa5565] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Astrocytes form interconnected networks in the brain and communicate via calcium signaling. We investigate how modes of coupling between astrocytes influence the spatio-temporal patterns of calcium signaling within astrocyte networks and specifically how these network interactions promote coordination within this group of cells. To investigate these complex phenomena, we study reduced cultured networks of astrocytes and neurons. We image the spatial temporal patterns of astrocyte calcium activity and quantify how perturbing the coupling between astrocytes influences astrocyte activity patterns. To gain insight into the pattern formation observed in these cultured networks, we compare the experimentally observed calcium activity patterns to the patterns produced by a reduced computational model, where we represent astrocytes as simple units that integrate input through two mechanisms: gap junction coupling (network transport) and chemical release (extracellular diffusion). We examine the activity patterns in the simulated astrocyte network and their dependence upon these two coupling mechanisms. We find that gap junctions and extracellular chemical release interact in astrocyte networks to modulate the spatiotemporal patterns of their calcium dynamics. We show agreement between the computational and experimental findings, which suggests that the complex global patterns can be understood as a result of simple local coupling mechanisms.
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Affiliation(s)
- E. Shtrahman
- Applied Physics Program, University of Michigan – Ann Arbor 48109, USA
| | - D. Maruyama
- Department of Physics, University of Michigan - Ann Arbor 48109, USA
| | - E. Olariu
- Department of Physics, University of Michigan - Ann Arbor 48109, USA
| | - C.G. Fink
- Department of Physics, Ohio Wesleyan University -- Delaware 43015, USA
- Neuroscience Program, Ohio Wesleyan University -- Delaware 43015, USA
| | - M. Zochowski
- Department of Physics, University of Michigan - Ann Arbor 48109, USA
- Biophysics Program, University of Michigan - Ann Arbor 48109, USA
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167
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Agarwal A, Wu PH, Hughes EG, Fukaya M, Tischfield MA, Langseth AJ, Wirtz D, Bergles DE. Transient Opening of the Mitochondrial Permeability Transition Pore Induces Microdomain Calcium Transients in Astrocyte Processes. Neuron 2017; 93:587-605.e7. [PMID: 28132831 DOI: 10.1016/j.neuron.2016.12.034] [Citation(s) in RCA: 287] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 10/04/2016] [Accepted: 12/20/2016] [Indexed: 12/15/2022]
Abstract
Astrocytes extend highly branched processes that form functionally isolated microdomains, facilitating local homeostasis by redistributing ions, removing neurotransmitters, and releasing factors to influence blood flow and neuronal activity. Microdomains exhibit spontaneous increases in calcium (Ca2+), but the mechanisms and functional significance of this localized signaling are unknown. By developing conditional, membrane-anchored GCaMP3 mice, we found that microdomain activity that occurs in the absence of inositol triphosphate (IP3)-dependent release from endoplasmic reticulum arises through Ca2+ efflux from mitochondria during brief openings of the mitochondrial permeability transition pore. These microdomain Ca2+ transients were facilitated by the production of reactive oxygen species during oxidative phosphorylation and were enhanced by expression of a mutant form of superoxide dismutase 1 (SOD1 G93A) that causes astrocyte dysfunction and neurodegeneration in amyotrophic lateral sclerosis (ALS). By localizing mitochondria to microdomains, astrocytes ensure local metabolic support for energetically demanding processes and enable coupling between metabolic demand and Ca2+ signaling events.
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Affiliation(s)
- Amit Agarwal
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Pei-Hsun Wu
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ethan G Hughes
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Masahiro Fukaya
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara 252-0374, Japan
| | - Max A Tischfield
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Abraham J Langseth
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Denis Wirtz
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Dwight E Bergles
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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168
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Barzilai A, Schumacher B, Shiloh Y. Genome instability: Linking ageing and brain degeneration. Mech Ageing Dev 2017; 161:4-18. [DOI: 10.1016/j.mad.2016.03.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/23/2016] [Accepted: 03/26/2016] [Indexed: 02/06/2023]
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169
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von Bartheld CS, Bahney J, Herculano-Houzel S. The search for true numbers of neurons and glial cells in the human brain: A review of 150 years of cell counting. J Comp Neurol 2016; 524:3865-3895. [PMID: 27187682 PMCID: PMC5063692 DOI: 10.1002/cne.24040] [Citation(s) in RCA: 566] [Impact Index Per Article: 70.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 05/13/2016] [Accepted: 05/16/2016] [Indexed: 12/13/2022]
Abstract
For half a century, the human brain was believed to contain about 100 billion neurons and one trillion glial cells, with a glia:neuron ratio of 10:1. A new counting method, the isotropic fractionator, has challenged the notion that glia outnumber neurons and revived a question that was widely thought to have been resolved. The recently validated isotropic fractionator demonstrates a glia:neuron ratio of less than 1:1 and a total number of less than 100 billion glial cells in the human brain. A survey of original evidence shows that histological data always supported a 1:1 ratio of glia to neurons in the entire human brain, and a range of 40-130 billion glial cells. We review how the claim of one trillion glial cells originated, was perpetuated, and eventually refuted. We compile how numbers of neurons and glial cells in the adult human brain were reported and we examine the reasons for an erroneous consensus about the relative abundance of glial cells in human brains that persisted for half a century. Our review includes a brief history of cell counting in human brains, types of counting methods that were and are employed, ranges of previous estimates, and the current status of knowledge about the number of cells. We also discuss implications and consequences of the new insights into true numbers of glial cells in the human brain, and the promise and potential impact of the newly validated isotropic fractionator for reliable quantification of glia and neurons in neurological and psychiatric diseases. J. Comp. Neurol. 524:3865-3895, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
| | - Jami Bahney
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Suzana Herculano-Houzel
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, and Instituto Nacional de Neurociência Translacional, CNPq/MCT, Brasil
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170
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Colombo JA. The interlaminar glia: from serendipity to hypothesis. Brain Struct Funct 2016; 222:1109-1129. [DOI: 10.1007/s00429-016-1332-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 10/21/2016] [Indexed: 11/24/2022]
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171
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Adams SR, Mackey MR, Ramachandra R, Palida Lemieux SF, Steinbach P, Bushong EA, Butko MT, Giepmans BNG, Ellisman MH, Tsien RY. Multicolor Electron Microscopy for Simultaneous Visualization of Multiple Molecular Species. Cell Chem Biol 2016; 23:1417-1427. [PMID: 27818300 DOI: 10.1016/j.chembiol.2016.10.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 08/16/2016] [Accepted: 10/12/2016] [Indexed: 11/24/2022]
Abstract
Electron microscopy (EM) remains the primary method for imaging cellular and tissue ultrastructure, although simultaneous localization of multiple specific molecules continues to be a challenge for EM. We present a method for obtaining multicolor EM views of multiple subcellular components. The method uses sequential, localized deposition of different lanthanides by photosensitizers, small-molecule probes, or peroxidases. Detailed view of biological structures is created by overlaying conventional electron micrographs with pseudocolor lanthanide elemental maps derived from distinctive electron energy-loss spectra of each lanthanide deposit via energy-filtered transmission electron microscopy. This results in multicolor EM images analogous to multicolor fluorescence but with the benefit of the full spatial resolution of EM. We illustrate the power of this methodology by visualizing hippocampal astrocytes to show that processes from two astrocytes can share a single synapse. We also show that polyarginine-based cell-penetrating peptides enter the cell via endocytosis, and that newly synthesized PKMζ in cultured neurons preferentially localize to the postsynaptic membrane.
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Affiliation(s)
- Stephen R Adams
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Mason R Mackey
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ranjan Ramachandra
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093, USA
| | | | - Paul Steinbach
- Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA 92093, USA
| | - Eric A Bushong
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Margaret T Butko
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ben N G Giepmans
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA 92093, USA; Department of Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Roger Y Tsien
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA 92093, USA; Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
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172
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Xu MX, Yu R, Shao LF, Zhang YX, Ge CX, Liu XM, Wu WY, Li JM, Kong LD. Up-regulated fractalkine (FKN) and its receptor CX3CR1 are involved in fructose-induced neuroinflammation: Suppression by curcumin. Brain Behav Immun 2016; 58:69-81. [PMID: 26765996 DOI: 10.1016/j.bbi.2016.01.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 12/08/2015] [Accepted: 01/01/2016] [Indexed: 12/11/2022] Open
Abstract
Recent studies suggest that diet-induced fractalkine (FKN) stimulates neuroinflammation in animal models of obesity, yet how it occurs is unclear. This study investigated the role of FKN and it receptor, CX3CR1, in fructose-induced neuroinflammation, and examined curcumin's beneficial effect. Fructose feeding was found to induce hippocampal microglia activation with neuroinflammation through the activation of the Toll-like receptor 4 (TLR4)/nuclear transcription factor κB (NF-κB) signaling, resulting in the reduction of neurogenesis in the dentate gyrus (DG) of mice. Serum FKN levels, as well as hypothalamic FKN and CX3CR1 gene expression, were significantly increased in fructose-fed mice with hypothalamic microglia activation. Hippocampal gene expression of FKN and CX3CR1 was also up-regulated at 14d and normalized at 56d in mice fed with fructose, which were consistent with the change of GFAP. Furthermore, immunostaining showed that GFAP and FKN expression was increased in cornu amonis 1, but decreased in DG in fructose-fed mice. In vitro studies showed that GFAP and FKN expression was stimulated in astrocytes, and suppressed in mixed glial cells exposed to 48h-fructose, with the continual increase of pro-inflammatory cytokines. Thus, increased FKN and CX3CR1 may cause a cross-talk between activated glial cells and neurons, playing an important role in the development of neuroinflammation in fructose-fed mice. Curcumin protected against neuronal damage in hippocampal DG of fructose-fed mice by inhibiting microglia activation and suppressed FKN/CX3CR1 up-regulation in the neuronal network. These results suggest a new therapeutic approach to protect against neuronal damage associated with dietary obesity-associated neuroinflammation.
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Affiliation(s)
- Min-Xuan Xu
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, PR China
| | - Rong Yu
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, PR China
| | - Li-Fei Shao
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, PR China
| | - Yan-Xiu Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, PR China
| | - Chen-Xu Ge
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, PR China
| | - Xin-Meng Liu
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, PR China
| | - Wen-Yuan Wu
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, PR China
| | - Jian-Mei Li
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, PR China.
| | - Ling-Dong Kong
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, PR China.
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173
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Langer J, Gerkau NJ, Derouiche A, Kleinhans C, Moshrefi-Ravasdjani B, Fredrich M, Kafitz KW, Seifert G, Steinhäuser C, Rose CR. Rapid sodium signaling couples glutamate uptake to breakdown of ATP in perivascular astrocyte endfeet. Glia 2016; 65:293-308. [PMID: 27785828 DOI: 10.1002/glia.23092] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/05/2016] [Accepted: 10/06/2016] [Indexed: 12/19/2022]
Abstract
Perivascular endfeet of astrocytes are highly polarized compartments that ensheath blood vessels and contribute to the blood-brain barrier. They experience calcium transients with neuronal activity, a phenomenon involved in neurovascular coupling. Endfeet also mediate the uptake of glucose from the blood, a process stimulated in active brain regions. Here, we demonstrate in mouse hippocampal tissue slices that endfeet undergo sodium signaling upon stimulation of glutamatergic synaptic activity. Glutamate-induced endfeet sodium transients were diminished by TFB-TBOA, suggesting that they were generated by sodium-dependent glutamate uptake. With local agonist application, they could be restricted to endfeet and immunohistochemical analysis revealed prominent expression of glutamate transporters GLAST and GLT-1 localized towards the neuropil vs. the vascular side of endfeet. Endfeet sodium signals spread at an apparent maximum velocity of ∼120 µm/s and directly propagated from stimulated into neighboring endfeet; this spread was omitted in Cx30/Cx43 double-deficient mice. Sodium transients resulted in elevation of intracellular magnesium, indicating a decrease in intracellular ATP. In summary, our results establish that excitatory synaptic activity and stimulation of glutamate uptake in astrocytes trigger transient sodium increases in perivascular endfeet which rapidly spread through gap junctions into neighboring endfeet and cause a reduction of intracellular ATP. The newly discovered endfeet sodium signaling thereby represents a fast, long-lived and inter-cellularly acting indicator of synaptic activity at the blood-brain barrier, which likely constitutes an important component of neuro-metabolic coupling in the brain. GLIA 2017;65:293-308.
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Affiliation(s)
- Julia Langer
- Faculty of Mathematics and Natural Sciences, Institute of Neurobiology, Heinrich Heine University Duesseldorf, Universitätsstrasse 1, Duesseldorf, D-40225, Germany
| | - Niklas J Gerkau
- Faculty of Mathematics and Natural Sciences, Institute of Neurobiology, Heinrich Heine University Duesseldorf, Universitätsstrasse 1, Duesseldorf, D-40225, Germany
| | - Amin Derouiche
- Institute of Anatomy II and Dr. Senckenbergisches Chronomedizinisches Institut, Goethe-University of Frankfurt, Theodor-Stern-Kai 7, Frankfurt/M, D-60590, Germany
| | - Christian Kleinhans
- Faculty of Mathematics and Natural Sciences, Institute of Neurobiology, Heinrich Heine University Duesseldorf, Universitätsstrasse 1, Duesseldorf, D-40225, Germany
| | - Behrouz Moshrefi-Ravasdjani
- Faculty of Mathematics and Natural Sciences, Institute of Neurobiology, Heinrich Heine University Duesseldorf, Universitätsstrasse 1, Duesseldorf, D-40225, Germany
| | - Michaela Fredrich
- Institute of Anatomy II and Dr. Senckenbergisches Chronomedizinisches Institut, Goethe-University of Frankfurt, Theodor-Stern-Kai 7, Frankfurt/M, D-60590, Germany
| | - Karl W Kafitz
- Faculty of Mathematics and Natural Sciences, Institute of Neurobiology, Heinrich Heine University Duesseldorf, Universitätsstrasse 1, Duesseldorf, D-40225, Germany
| | - Gerald Seifert
- Medical Faculty, Institute of Cellular Neurosciences, University of Bonn, Bonn, D-53105, Germany
| | - Christian Steinhäuser
- Medical Faculty, Institute of Cellular Neurosciences, University of Bonn, Bonn, D-53105, Germany
| | - Christine R Rose
- Faculty of Mathematics and Natural Sciences, Institute of Neurobiology, Heinrich Heine University Duesseldorf, Universitätsstrasse 1, Duesseldorf, D-40225, Germany
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174
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Xu Y, Cheng G, Zhu Y, Zhang X, Pu S, Wu J, Lv Y, Du D. Anti-nociceptive roles of the glia-specific metabolic inhibitor fluorocitrate in paclitaxel-evoked neuropathic pain. Acta Biochim Biophys Sin (Shanghai) 2016; 48:902-908. [PMID: 27563006 DOI: 10.1093/abbs/gmw083] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 07/26/2016] [Indexed: 12/22/2022] Open
Abstract
Paclitaxel (Taxol) is a powerful chemotherapy drug used in breast cancers, but it often causes neuropathic pain, leading to the early cessation of therapy and poor treatment outcomes. Approaches for the management of paclitaxel-induced neuropathic pain are urgently needed. The involvement of spinal astrocytes in the pathogenesis of paclitaxel-induced neuropathy has been reported, but little is known about the role of fluorocitrate (FC), a selective inhibitor of astrocyte activation, during neuropathic pain related to paclitaxel treatment. In this study, we investigated the effects of FC on paclitaxel-induced neuropathic pain. Glial fibrillary acidic protein (GFAP) expression was determined to assess astrocyte activation. To explore the mechanisms involved, the expression of glial glutamate transporter 1 (GLT-1) and the activation of mitogen-activated protein kinases in the spinal dorsal horn were analyzed. The results showed that paclitaxel decreased the mechanical nociceptive thresholds and increased GFAP expression, leading to spinal astrocyte activation. After paclitaxel treatment, GLT-1 was significantly down-regulated, and the phosphorylation of ERK1/2 and JNK were obviously up-regulated. However, paclitaxel treatment did not increase p38 phosphorylation. Additional studies showed that paclitaxel-evoked mechanical hypersensitivity was reduced by FC treatment. Moreover, FC treatment inhibited the activation of astrocytes and reversed the changes in GLT-1 expression and MAPK phosphorylation. Further study indicated that FC did not influence the antitumor effect of paclitaxel, suggesting that FC blocked paclitaxel-induced neuropathic pain without antagonizing its antitumor effect. Together, these results suggested that paclitaxel induced astrocyte-specific activation, which may contribute to mechanical allodynia and hyperalgesia, and that FC could be a potential therapeutic agent for paclitaxel-induced neuropathic pain.
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Affiliation(s)
- Yongming Xu
- Pain Management Center and Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiaotong University, Shanghai 200233, China
| | - Guangxia Cheng
- Department of Clinical Laboratory, Jinan Infectious Disease Hospital, Shandong University, Jinan 250021, China
| | - Yanrong Zhu
- Department of Clinical Laboratory, Liaocheng People's Hospital, Liaocheng 252000, China
| | - Xin Zhang
- Pain Management Center and Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiaotong University, Shanghai 200233, China
| | - Shaofeng Pu
- Pain Management Center and Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiaotong University, Shanghai 200233, China
| | - Junzhen Wu
- Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiaotong University, Shanghai 200233, China
| | - Yingying Lv
- Pain Management Center and Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiaotong University, Shanghai 200233, China
| | - Dongping Du
- Pain Management Center and Department of Anesthesiology, Shanghai Sixth People's Hospital, Shanghai Jiaotong University, Shanghai 200233, China
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175
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Chi-Castañeda D, Ortega A. Clock Genes in Glia Cells: A Rhythmic History. ASN Neuro 2016; 8:8/5/1759091416670766. [PMID: 27666286 PMCID: PMC5037500 DOI: 10.1177/1759091416670766] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 08/22/2016] [Indexed: 11/17/2022] Open
Abstract
Circadian rhythms are periodic patterns in biological processes that allow the organisms to anticipate changes in the environment. These rhythms are driven by the suprachiasmatic nucleus (SCN), the master circadian clock in vertebrates. At a molecular level, circadian rhythms are regulated by the so-called clock genes, which oscillate in a periodic manner. The protein products of clock genes are transcription factors that control their own and other genes’ transcription, collectively known as “clock-controlled genes.” Several brain regions other than the SCN express circadian rhythms of clock genes, including the amygdala, the olfactory bulb, the retina, and the cerebellum. Glia cells in these structures are expected to participate in rhythmicity. However, only certain types of glia cells may be called “glial clocks,” since they express PER-based circadian oscillators, which depend of the SCN for their synchronization. This contribution summarizes the current information about clock genes in glia cells, their plausible role as oscillators and their medical implications.
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Affiliation(s)
- Donají Chi-Castañeda
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, México Soluciones para un México Verde, S.A de C.V., Santa Fé Ciudad de México, México
| | - Arturo Ortega
- Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, México
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176
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Sugihara H, Chen N, Sur M. Cell-specific modulation of plasticity and cortical state by cholinergic inputs to the visual cortex. JOURNAL OF PHYSIOLOGY, PARIS 2016; 110:37-43. [PMID: 27840211 PMCID: PMC5769868 DOI: 10.1016/j.jphysparis.2016.11.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 11/08/2016] [Accepted: 11/09/2016] [Indexed: 12/18/2022]
Abstract
Acetylcholine (ACh) modulates diverse vital brain functions. Cholinergic neurons from the basal forebrain innervate a wide range of cortical areas, including the primary visual cortex (V1), and multiple cortical cell types have been found to be responsive to ACh. Here we review how different cell types contribute to different cortical functions modulated by ACh. We specifically focus on two major cortical functions: plasticity and cortical state. In layer II/III of V1, ACh acting on astrocytes and somatostatin-expressing inhibitory neurons plays critical roles in these functions. Cell type specificity of cholinergic modulation points towards the growing understanding that even diffuse neurotransmitter systems can mediate specific functions through specific cell classes and receptors.
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Affiliation(s)
- Hiroki Sugihara
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Naiyan Chen
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A(∗)STAR, Republic of Singapore
| | - Mriganka Sur
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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177
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Haydon PG. The Evolving View of Astrocytes. CEREBRUM : THE DANA FORUM ON BRAIN SCIENCE 2016; 2016:cer-12-16. [PMID: 28058092 PMCID: PMC5198755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Did you know that glial cells are more numerous than neurons in the brain? Scientists have found that one type of glial cell that is prevalent in the cortex-the astrocyte-communicates with its brethren, sends information to neurons, and controls blood flow to regions of brain activity. Because of all these properties, and since the cortex is believed responsible for cognition, the role of astrocytes in sleep, learning, and memory is being determined.
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178
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Glia plasma membrane transporters: Key players in glutamatergic neurotransmission. Neurochem Int 2016; 98:46-55. [DOI: 10.1016/j.neuint.2016.04.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/07/2016] [Accepted: 04/06/2016] [Indexed: 12/27/2022]
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179
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Astrocyte Aquaporin Dynamics in Health and Disease. Int J Mol Sci 2016; 17:ijms17071121. [PMID: 27420057 PMCID: PMC4964496 DOI: 10.3390/ijms17071121] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/07/2016] [Accepted: 07/07/2016] [Indexed: 02/01/2023] Open
Abstract
The family of aquaporins (AQPs), membrane water channels, consists of diverse types of proteins that are mainly permeable to water; some are also permeable to small solutes, such as glycerol and urea. They have been identified in a wide range of organisms, from microbes to vertebrates and plants, and are expressed in various tissues. Here, we focus on AQP types and their isoforms in astrocytes, a major glial cell type in the central nervous system (CNS). Astrocytes have anatomical contact with the microvasculature, pia, and neurons. Of the many roles that astrocytes have in the CNS, they are key in maintaining water homeostasis. The processes involved in this regulation have been investigated intensively, in particular regulation of the permeability and expression patterns of different AQP types in astrocytes. Three aquaporin types have been described in astrocytes: aquaporins AQP1 and AQP4 and aquaglyceroporin AQP9. The aim here is to review their isoforms, subcellular localization, permeability regulation, and expression patterns in the CNS. In the human CNS, AQP4 is expressed in normal physiological and pathological conditions, but astrocytic expression of AQP1 and AQP9 is mainly associated with a pathological state.
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180
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Iwata M, Ota KT, Li XY, Sakaue F, Li N, Dutheil S, Banasr M, Duric V, Yamanashi T, Kaneko K, Rasmussen K, Glasebrook A, Koester A, Song D, Jones KA, Zorn S, Smagin G, Duman RS. Psychological Stress Activates the Inflammasome via Release of Adenosine Triphosphate and Stimulation of the Purinergic Type 2X7 Receptor. Biol Psychiatry 2016; 80:12-22. [PMID: 26831917 DOI: 10.1016/j.biopsych.2015.11.026] [Citation(s) in RCA: 272] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 11/24/2015] [Accepted: 11/24/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND The mechanisms underlying stress-induced inflammation that contribute to major depressive disorder are unknown. We examine the role of the adenosine triphosphate (ATP)/purinergic type 2X7 receptor (P2X7R) pathway and the NLRP3 (nucleotide-binding, leucine-rich repeat, pyrin domain containing 3) inflammasome in interleukin (IL)-1β and depressive behavioral responses to stress. METHODS The influence of acute restraint stress on extracellular ATP, glutamate, IL-1β, and tumor necrosis factor alpha in hippocampus was determined by microdialysis, and the influence of acute restraint stress on the NLRP3 inflammasome was determined by western blot analysis. The influence of P2X7R antagonist administration on IL-1β and tumor necrosis factor alpha and on anxiety and depressive behaviors was determined in the chronic unpredictable stress rodent model. The role of the NLRP3 inflammasome was determined by analysis of Nlrp3 null mice. RESULTS Acute restraint stress rapidly increased extracellular ATP, an endogenous agonist of P2X7R; the inflammatory cytokine IL-1β; and the active form of the NLRP3 inflammasome in the hippocampus. Administration of a P2X7R antagonist completely blocked the release of IL-1β and tumor necrosis factor alpha, another stress-induced cytokine, and activated NLRP3. Moreover, P2X7R antagonist administration reversed the anhedonic and anxiety behaviors caused by chronic unpredictable stress exposure, and deletion of the Nlrp3 gene rendered mice resistant to development of depressive behaviors caused by chronic unpredictable stress. CONCLUSIONS These findings demonstrate that psychological "stress" is sensed by the innate immune system in the brain via the ATP/P2X7R-NLRP3 inflammasome cascade, and they identify novel therapeutic targets for the treatment of stress-related mood disorders and comorbid illnesses.
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Affiliation(s)
- Masaaki Iwata
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Kristie T Ota
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Xiao-Yuan Li
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Fumika Sakaue
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Nanxin Li
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Sophie Dutheil
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Mounira Banasr
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Vanja Duric
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut; Department of Physiology and Pharmacology, Des Moines University, Des Moines, Iowa
| | | | - Koichi Kaneko
- Division of Neuropsychiatry, Tottori University, Tottori, Japan
| | - Kurt Rasmussen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Andrew Glasebrook
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Anja Koester
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Dekun Song
- Lundbeck Research USA, Paramus, New Jersey
| | | | | | | | - Ronald S Duman
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.
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181
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Abstract
Spinal muscular atrophy (SMA) is a motoneuron disease caused by loss or mutation in Survival of Motor Neuron 1 (SMN1) gene. Recent studies have shown that selective restoration of SMN protein in astrocytes partially alleviates pathology in an SMA mouse model, suggesting important roles for astrocytes in SMA. Addressing these underlying mechanisms may provide new therapeutic avenues to fight SMA. Using primary cultures of pure motoneurons or astrocytes from SMNΔ7 (SMA) and wild-type (WT) mice, as well as their mixed and matched cocultures, we characterized the contributions of motoneurons, astrocytes, and their interactions to synapse loss in SMA. In pure motoneuron cultures, SMA motoneurons exhibited normal survival but intrinsic defects in synapse formation and synaptic transmission. In pure astrocyte cultures, SMA astrocytes exhibited defects in calcium homeostasis. In motoneuron-astrocyte contact cocultures, synapse formation and synaptic transmission were significantly reduced when either motoneurons, astrocytes or both were from SMA mice compared with those in WT motoneurons cocultured with WT astrocytes. The reduced synaptic activity is unlikely due to changes in motoneuron excitability. This disruption in synapse formation and synaptic transmission by SMN deficiency was not detected in motoneuron-astrocyte noncontact cocultures. Additionally, we observed a downregulation of Ephrin B2 in SMA astrocytes. These findings suggest that there are both cell autonomous and non-cell-autonomous defects in SMA motoneurons and astrocytes. Defects in contact interactions between SMA motoneurons and astrocytes impair synaptogenesis seen in SMA pathology, possibly due to the disruption of the Ephrin B2 pathway.
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182
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Mitterauer B. Imbalance of Glial-Neuronal Interaction in Synapses: A Possible Mechanism of the Pathophysiology of Bipolar Disorder. Neuroscientist 2016; 10:199-206. [PMID: 15155059 DOI: 10.1177/107385403262248] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
There is a wave of new information suggesting that glia, especially astrocytes, are intimately involved in the active control of neuronal activity and synaptic transmission. Synaptically associated astrocytes should be viewed as integral modulatory elements of tripartite synapses consisting of the presynapse, the postsynapse, and the glial element (astrocytes). Smit and coworkers proposed a model of a cholinergic tripartite synapse based on the identification of a glial-derived binding protein (BP) that is secreted into the synapse and binds free acetylcholine (ACh), thus reducing the levels of ACh available for stimulating the postsynapse. Here the author proposes an explanatory model of the pathophysiology of bipolar disorder focusing on the possible dynamics in cholinergic tripartite synapses. The hypothesis is that an imbalance between neurotransmitters and glial BPs in the synaptic cleft is determined by glia. If glial BPs are overexpressed, synaptic transmission is suppressed because of reduced levels of bioavailable neurotransmitters. This state could cause a depression on the behavioral level. In contrast, if glial BPs are underexpressed, the excess of neurotransmitters in the cleft leads to an overbalanced state of synaptic information transmission. This state could cause manic behavior. Under certain conditions, underbalanced and overbalanced synapses at different locations in the same brain could disturb brain function in parallel causing a mixed episode of bipolar disorder. If glial BPs and mutations in genes expressing glial BPs in the various synapses of the brain are identified, this hypothesis can be experimentally tested.
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Affiliation(s)
- Bernhard Mitterauer
- Institute of Forensic Neuropsychiatry and Gotthard Günther Archives, University of Salzburg, Austria.
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183
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Mitterauer B. Nonfunctional Glial Proteins in Tripartite Synapses: A Pathophysiological Model of Schizophrenia. Neuroscientist 2016; 11:192-8. [PMID: 16013114 DOI: 10.1177/1073858404265745] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A model for the pathophysiology of schizophrenia is proposed that focuses on an unbalance of transmission in tripartite synapses. Synaptically associated astrocytes should be viewed as integral modulatory elements of tripartite synapses consisting of the presynapse, the postsynapse, and the glial element. Astrocytes may secrete glial binding protein into the synaptic cleft, thus binding free neurotransmitters and thereby reducing the levels of neurotransmitters available for stimulating the postsynapse. Astrocytes also have membrane-bound receptors for neurotransmitters, and when these bind neurotransmitters, the astrocytes upregulate the amount of binding protein secreted into the synapse, resulting in a negative feedback to the presynaptic terminal. The hypothesis presented here is that glia lose their negative feedback function due to loss of function mutations in the genes encoding the binding proteins and glial receptors. The mutations generate proteins that cannot be occupied by their cognate substances of the neuronal system, primarily neurotransmitters. Therefore, the glial-neuronal interaction in tripartite synapses affected becomes totally unbalanced, and the glia lose their inhibitory or boundary-setting function. As a result, neural flux is unconstrained by normal glial boundaries, also the flux of thought on the phenomenological level. Schizophrenia may be caused by the inability to delimit conceptual boundaries.
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Affiliation(s)
- Bernhard Mitterauer
- Institute of Forensic Neuropsychiatry and Gotthard Günther Archives, University of Salzburg, Austria.
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184
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Abstract
Neurons and glia are the principal cellular components of the nervous system. Although the glia are 10 times more numerous than neurons, until recently they were thought to be passive cells that monitor and support the active neurons by taking up used neurotransmitters from the synapses. In the past few years, this concept has been challenged by the findings that Ca2+ waves spread from one astrocyte to another via Ca2+-and SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor)-dependent gliotransmitter release in pure cultures of astrocytes, raising the possibility that glia are not so passive as previously thought. This hypothesis was further advanced by two recent reports, which demonstrated that astrocytes release glutamate via vesicular exocytosis in response to stimuli. The kinetics of single vesicle exocytosis is distinct from its neural equivalent, because in response to physiological stimulation, gliotransmitter release is exclusively in the mode of “kiss and run.” These advances were made possible by newly available techniques for single vesicle recordings, which will also be briefly reviewed here.
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Affiliation(s)
- Xiao-Ke Chen
- Institute of Molecular Medicine, Peking University, 5 Yi-He-Yuan Road, Beijing 100871, China
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185
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Abstract
Compelling new findings have revealed that receptor tyrosine kinases of the Eph family, along with their ephrin ligands, play an essential role in regulating the properties of developing mature excitatory synapses in the central nervous system. The cell surface localization of both the Eph receptors and the ephrins enables these proteins to signal bidirectionally at sites of cell-to-cell contact, such as synapses. Eph receptors and ephrins have indeed been implicated in multiple aspects of synaptic function, including clustering and modulating N-methyl-D-aspartate receptors, modifying the geometry of postsynaptic terminals, and influencing long-term synaptic plasticity and memory. In this review, we discuss how Eph receptors and ephrins are integrated into the molecular machinery that supports synaptic function.
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Affiliation(s)
- Keith K Murai
- Centre for Research in Neuroscience, McGill University Health Centre, Montreal General Hospital, Montreal, Canada
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186
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Sun XD, Li L, Liu F, Huang ZH, Bean JC, Jiao HF, Barik A, Kim SM, Wu H, Shen C, Tian Y, Lin TW, Bates R, Sathyamurthy A, Chen YJ, Yin DM, Xiong L, Lin HP, Hu JX, Li BM, Gao TM, Xiong WC, Mei L. Lrp4 in astrocytes modulates glutamatergic transmission. Nat Neurosci 2016; 19:1010-8. [PMID: 27294513 PMCID: PMC4961622 DOI: 10.1038/nn.4326] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 05/08/2016] [Indexed: 02/06/2023]
Abstract
Neurotransmission requires precise control of neurotransmitter release from axon terminals. This process is regulated by glial cells; however, underlying mechanisms are not fully understood. Here we report that glutamate release in the brain is impaired in mice lacking low density lipoprotein receptor-related protein 4 (Lrp4), a protein critical for neuromuscular junction formation. Electrophysiological studies indicate compromised release probability in astrocyte-specific Lrp4 knockout mice. Lrp4 mutant astrocytes suppress glutamate transmission by enhancing the release of ATP, whose levels are elevated in the hippocampus of Lrp4 mutant mice. Consequently, the mutant mice are impaired in locomotor activity and spatial memory and are resistant to seizure induction. These impairments could be ameliorated by adenosine A1 receptor antagonist. The results reveal a critical role of Lrp4, in response to agrin, in modulating astrocytic ATP release and synaptic transmission. Our study provides insight into the interaction between neurons and astrocytes for synaptic homeostasis and/or plasticity.
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Affiliation(s)
- Xiang-Dong Sun
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Lei Li
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Fang Liu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Zhi-Hui Huang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Jonathan C Bean
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Hui-Feng Jiao
- Center for Neuropsychiatric Diseases, Institute of Life Science, Nanchang University, Nanchang, China
| | - Arnab Barik
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Seon-Myung Kim
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Haitao Wu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Chengyong Shen
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Yun Tian
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Thiri W Lin
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Ryan Bates
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Anupama Sathyamurthy
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Yong-Jun Chen
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Dong-Min Yin
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Lei Xiong
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Hui-Ping Lin
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Jin-Xia Hu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA
| | - Bao-Ming Li
- Center for Neuropsychiatric Diseases, Institute of Life Science, Nanchang University, Nanchang, China.,Jiangxi Medical School, Nanchang University, Nanchang, China
| | - Tian-Ming Gao
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Department of Neurobiology, Southern Medical University, Guangzhou, China
| | - Wen-Cheng Xiong
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA.,Charlie Norwood Virginia Medical Center, Augusta, Georgia, USA
| | - Lin Mei
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Georgia, USA.,Center for Neuropsychiatric Diseases, Institute of Life Science, Nanchang University, Nanchang, China.,Jiangxi Medical School, Nanchang University, Nanchang, China.,Charlie Norwood Virginia Medical Center, Augusta, Georgia, USA
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187
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Sun WC, Pei L. rno-miR-665 targets BCL2L1 (Bcl-xl) and increases vulnerability to propofol in developing astrocytes. J Neurochem 2016; 138:233-42. [PMID: 27121046 DOI: 10.1111/jnc.13647] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 02/25/2016] [Accepted: 03/21/2016] [Indexed: 11/29/2022]
Abstract
Propofol exerts a cytotoxic influence over immature neurocytes. Our previous study revealed that clinically relevant doses of propofol accelerated apoptosis of primary cultured astrocytes of developing rodent brains via rno-miR-665 regulation. However, the role of rno-miR-665 during the growth spurt of neonatal rodent brains in vivo is still uncertain. Post-natal day 7 (P7) rats received a single injection of propofol 30 mg/kg intraperitoneally (i.p.), and neuroapoptosis of hippocampal astrocytes was analyzed by immunofluorescence and scanning electron microscopy. The differential expression of rno-miR-665, BCL2L1 (Bcl-xl), and cleaved caspase 3 (CC3) was surveyed by qRT-PCR and western blotting. In addition, the utility of A-1155463, a highly potent and BCL2L1-selective antagonist, was aimed to assess the contribution of BCL2L1 for neuroglial survival. Following the intraventricular injection of lentivirus rno-miR-665, neuroprotection was detected by 5-point scale measurement. The single dose of propofol 30 mg/kg triggered dose-dependent apoptosis of developing hippocampal astrocytes. Meanwhile, propofol triggered both rno-miR-665 and CC3, and depressed BCL2L1, which was predicted as one target gene of rno-miR-665. Combination treatment with A-1155463 and propofol induced lower mRNA and protein levels of BCL2L1 and more CC3 activation than propofol treatment alone in vivo. The lentivirus-mediated knockdown of rno-miR-665 elevated BCL2L1 and attenuated CC3 levels, whereas up-regulation of rno-miR-665 suppressed BCL2L1 and induced CC3 expression in vivo. More importantly, rno-miR-665 antagomir infusion improved neurological outcomes of pups receiving propofol during the brain growth spurt. Rno-miR-665, providing a potential target for alternative therapeutics for pediatric anesthesia, is susceptible to propofol by negatively targeting antiapoptotic BCL2L1. Relatively little is known about the association between exposure of astrocytes to brief propofol anaesthesia and risk for impairment. Here, it revealed that propofol-related neurotoxicity of neonatal astrocytes was under rno-miR-665 regulation during the brain growth spurt. Rno-miR-665 might act as a clinically alternative therapeutic target for treatment of neurological disorders in peadiatric anesthesia or sedation with propofol in future.
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Affiliation(s)
- Wen-Chong Sun
- Department of Anesthesiology, the First Affiliated Hospital, China Medical University, Shenyang, Liaoning, China
| | - Ling Pei
- Department of Anesthesiology, the First Affiliated Hospital, China Medical University, Shenyang, Liaoning, China
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188
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Kaminsky N, Bihari O, Kanner S, Barzilai A. Connecting Malfunctioning Glial Cells and Brain Degenerative Disorders. GENOMICS, PROTEOMICS & BIOINFORMATICS 2016; 14:155-165. [PMID: 27245308 PMCID: PMC4936608 DOI: 10.1016/j.gpb.2016.04.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 12/19/2022]
Abstract
The DNA damage response (DDR) is a complex biological system activated by different types of DNA damage. Mutations in certain components of the DDR machinery can lead to genomic instability disorders that culminate in tissue degeneration, premature aging, and various types of cancers. Intriguingly, malfunctioning DDR plays a role in the etiology of late onset brain degenerative disorders such as Parkinson's, Alzheimer's, and Huntington's diseases. For many years, brain degenerative disorders were thought to result from aberrant neural death. Here we discuss the evidence that supports our novel hypothesis that brain degenerative diseases involve dysfunction of glial cells (astrocytes, microglia, and oligodendrocytes). Impairment in the functionality of glial cells results in pathological neuro-glial interactions that, in turn, generate a "hostile" environment that impairs the functionality of neuronal cells. These events can lead to systematic neural demise on a scale that appears to be proportional to the severity of the neurological deficit.
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Affiliation(s)
- Natalie Kaminsky
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ofer Bihari
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sivan Kanner
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel.
| | - Ari Barzilai
- Department of Neurobiology, George S. Wise, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel.
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189
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Ravin R, Blank PS, Busse B, Ravin N, Vira S, Bezrukov L, Waters H, Guerrero-Cazares H, Quinones-Hinojosa A, Lee PR, Fields RD, Bezrukov SM, Zimmerberg J. Blast shockwaves propagate Ca(2+) activity via purinergic astrocyte networks in human central nervous system cells. Sci Rep 2016; 6:25713. [PMID: 27162174 PMCID: PMC4861979 DOI: 10.1038/srep25713] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 04/21/2016] [Indexed: 12/26/2022] Open
Abstract
In a recent study of the pathophysiology of mild, blast-induced traumatic brain injury (bTBI) the exposure of dissociated, central nervous system (CNS) cells to simulated blast resulted in propagating waves of elevated intracellular Ca2+. Here we show, in dissociated human CNS cultures, that these calcium waves primarily propagate through astrocyte-dependent, purinergic signaling pathways that are blocked by P2 antagonists. Human, compared to rat, astrocytes had an increased calcium response and prolonged calcium wave propagation kinetics, suggesting that in our model system rat CNS cells are less responsive to simulated blast. Furthermore, in response to simulated blast, human CNS cells have increased expressions of a reactive astrocyte marker, glial fibrillary acidic protein (GFAP) and a protease, matrix metallopeptidase 9 (MMP-9). The conjoint increased expression of GFAP and MMP-9 and a purinergic ATP (P2) receptor antagonist reduction in calcium response identifies both potential mechanisms for sustained changes in brain function following primary bTBI and therapeutic strategies targeting abnormal astrocyte activity.
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Affiliation(s)
- Rea Ravin
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1855, USA.,Celoptics Inc., Rockville, MD 20852, USA
| | - Paul S Blank
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1855, USA
| | - Brad Busse
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1855, USA
| | - Nitay Ravin
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1855, USA.,Celoptics Inc., Rockville, MD 20852, USA
| | - Shaleen Vira
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1855, USA
| | - Ludmila Bezrukov
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1855, USA
| | - Hang Waters
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1855, USA
| | | | | | - Philip R Lee
- Section on Nervous System Development and Plasticity, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-3713, USA
| | - R Douglas Fields
- Section on Nervous System Development and Plasticity, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-3713, USA
| | - Sergey M Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-0924, USA
| | - Joshua Zimmerberg
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1855, USA
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190
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Li X, Aleardi A, Wang J, Zhou Y, Andrade R, Hu Z. Differentiation of Spiral Ganglion-Derived Neural Stem Cells into Functional Synaptogenetic Neurons. Stem Cells Dev 2016; 25:803-13. [PMID: 27021700 DOI: 10.1089/scd.2015.0345] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Spiral ganglion neurons (SGNs) are usually damaged in sensorineural hearing loss. SGN-derived neural stem cells (NSCs) have been identified and proposed to differentiate into neurons to replace damaged SGNs. However, it remains obscure whether SGN-NSC-derived neurons (ScNs) are electrophysiologically functional and possess the capability to form neural connections. Here, we found that SGN-derived cells demonstrated NSC characteristics and differentiated into SGN-like glutamatergic neurons. Neurotrophins significantly increased neuronal differentiation and neurite length of ScNs. Patch clamp recording revealed that ScNs possessed SGN-like NaV and HCN channels, suggesting electrophysiological function. FM1-43 staining and synaptic protein immunofluorescence showed ScNs possess the ability to form neural connections. Astrocyte-conditioned medium was able to stimulate ScNs to express synaptic proteins. These data suggested that neurotrophins are able to stimulate postnatal SGN-NSCs to differentiate into functional glutamatergic ScNs with the capability to form synaptic connections in vitro.
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Affiliation(s)
- Xiaoyang Li
- 1 Department of Otolaryngology-HNS, Wayne State University School of Medicine , Detroit, Michigan
| | - Alicia Aleardi
- 2 Department of Pharmacology, Wayne State University School of Medicine , Detroit, Michigan
| | - Jue Wang
- 1 Department of Otolaryngology-HNS, Wayne State University School of Medicine , Detroit, Michigan
| | - Yang Zhou
- 1 Department of Otolaryngology-HNS, Wayne State University School of Medicine , Detroit, Michigan
| | - Rodrigo Andrade
- 2 Department of Pharmacology, Wayne State University School of Medicine , Detroit, Michigan
| | - Zhengqing Hu
- 1 Department of Otolaryngology-HNS, Wayne State University School of Medicine , Detroit, Michigan
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191
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Modulation of Synaptic Plasticity by Glutamatergic Gliotransmission: A Modeling Study. Neural Plast 2016; 2016:7607924. [PMID: 27195153 PMCID: PMC4852535 DOI: 10.1155/2016/7607924] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 02/15/2016] [Indexed: 01/03/2023] Open
Abstract
Glutamatergic gliotransmission, that is, the release of glutamate from perisynaptic astrocyte processes in an activity-dependent manner, has emerged as a potentially crucial signaling pathway for regulation of synaptic plasticity, yet its modes of expression and function in vivo remain unclear. Here, we focus on two experimentally well-identified gliotransmitter pathways, (i) modulations of synaptic release and (ii) postsynaptic slow inward currents mediated by glutamate released from astrocytes, and investigate their possible functional relevance on synaptic plasticity in a biophysical model of an astrocyte-regulated synapse. Our model predicts that both pathways could profoundly affect both short- and long-term plasticity. In particular, activity-dependent glutamate release from astrocytes could dramatically change spike-timing-dependent plasticity, turning potentiation into depression (and vice versa) for the same induction protocol.
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192
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Miro1 Regulates Activity-Driven Positioning of Mitochondria within Astrocytic Processes Apposed to Synapses to Regulate Intracellular Calcium Signaling. J Neurosci 2016; 35:15996-6011. [PMID: 26631479 DOI: 10.1523/jneurosci.2068-15.2015] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
It is fast emerging that maintaining mitochondrial function is important for regulating astrocyte function, although the specific mechanisms that govern astrocyte mitochondrial trafficking and positioning remain poorly understood. The mitochondrial Rho-GTPase 1 protein (Miro1) regulates mitochondrial trafficking and detachment from the microtubule transport network to control activity-dependent mitochondrial positioning in neurons. However, whether Miro proteins are important for regulating signaling-dependent mitochondrial dynamics in astrocytic processes remains unclear. Using live-cell confocal microscopy of rat organotypic hippocampal slices, we find that enhancing neuronal activity induces transient mitochondrial remodeling in astrocytes, with a concomitant, transient reduction in mitochondrial trafficking, mediated by elevations in intracellular Ca(2+). Stimulating neuronal activity also induced mitochondrial confinement within astrocytic processes in close proximity to synapses. Furthermore, we show that the Ca(2+)-sensing EF-hand domains of Miro1 are important for regulating mitochondrial trafficking in astrocytes and required for activity-driven mitochondrial confinement near synapses. Additionally, activity-dependent mitochondrial positioning by Miro1 reciprocally regulates the levels of intracellular Ca(2+) in astrocytic processes. Thus, the regulation of intracellular Ca(2+) signaling, dependent on Miro1-mediated mitochondrial positioning, could have important consequences for astrocyte Ca(2+) wave propagation, gliotransmission, and ultimately neuronal function.
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193
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Potokar M, Jorgačevski J, Lacovich V, Kreft M, Vardjan N, Bianchi V, D'Adamo P, Zorec R. Impaired αGDI Function in the X-Linked Intellectual Disability: The Impact on Astroglia Vesicle Dynamics. Mol Neurobiol 2016; 54:2458-2468. [PMID: 26971292 DOI: 10.1007/s12035-016-9834-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 03/04/2016] [Indexed: 11/25/2022]
Abstract
X-linked non-syndromic intellectual disability (XLID) is a common mental disorder recognized by cognitive and behavioral deficits. Mutations in the brain-specific αGDI, shown to alter a subset of RAB GTPases redistribution in cells, are linked to XLID, likely via changes in vesicle traffic in neurons. Here, we show directly that isolated XLID mice astrocytes, devoid of pathologic tissue environment, exhibit vesicle mobility deficits. Contrary to previous studies, we show that astrocytes express two GDI proteins. The siRNA-mediated suppression of expression of αGDI especially affected vesicle dynamics. A similar defect was recorded in astrocytes from the Gdi1 -/Y mouse model of XLID and in astrocytes with recombinant mutated human XLID αGDI. Endolysosomal vesicles studied here are involved in the release of gliosignaling molecules as well as in regulating membrane receptor density; thus, the observed changes in astrocytic vesicle mobility may, over the long time-course, profoundly affect signaling capacity of these cells, which optimize neural activity.
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Affiliation(s)
- Maja Potokar
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Jernej Jorgačevski
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | | | - Marko Kreft
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
- Biotechnical Faculty, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Nina Vardjan
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Veronica Bianchi
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Patrizia D'Adamo
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132, Milan, Italy
| | - Robert Zorec
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia.
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia.
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194
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Bowers MS, Jackson A, Maldoon PP, Damaj MI. N-acetylcysteine decreased nicotine reward-like properties and withdrawal in mice. Psychopharmacology (Berl) 2016; 233:995-1003. [PMID: 26676982 PMCID: PMC4819399 DOI: 10.1007/s00213-015-4179-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 12/02/2015] [Indexed: 12/26/2022]
Abstract
RATIONALE N-acetylcysteine can increase extrasynaptic glutamate and reduce nicotine self-administration in rats and smoking rates in humans. OBJECTIVES The aim of this study was to determine if N-acetylcysteine modulates the development of nicotine place conditioning and withdrawal in mice. METHODS N-acetylcysteine was given to nicotine-treated male ICR mice. Experiment 1: reward-like behavior. N-acetylcysteine (0, 5, 15, 30, or 60 mg/kg, i.p.) was given 15 min before nicotine (0.5 mg/kg, s.c.) or saline (10 ml/kg, s.c.) in an unbiased conditioned place preference (CPP) paradigm. Conditioning for highly palatable food served as control. Experiment 2: spontaneous withdrawal. The effect of N-acetylcysteine (0, 15, 30, 120 mg/kg, i.p.) on anxiety-like behavior, somatic signs, and hyperalgesia was measured 18-24 h after continuous nicotine (24 mg/kg/day, 14 days). Experiment 3: mecamylamine-precipitated, withdrawal-induced aversion. The effect of N-acetylcysteine (0, 15, 30, 120 mg/kg, i.p.) on mecamylamine (3.5 mg/kg, i.p.)-precipitated withdrawal was determined after continuous nicotine (24 mg/kg, i.p., 28 days) using the conditioned place aversion (CPA) paradigm. RESULTS Dose-related reductions in the development of nicotine CPP, somatic withdrawal signs, hyperalgesia, and CPA were observed after N-acetylcysteine pretreatment. No effect of N-acetylcysteine was found on palatable food CPP, anxiety-like behavior, or motoric capacity (crosses between plus maze arms). Finally, N-acetylcysteine did not affect any measure in saline-treated mice at doses effective in nicotine-treated mice. CONCLUSIONS These are the first data suggesting that N-acetylcysteine blocks specific mouse behaviors associated with nicotine reward and withdrawal, which adds to the growing appreciation that N-acetylcysteine may have high clinical utility in combating nicotine dependence.
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Affiliation(s)
- M S Bowers
- Department of Pharmacology/Toxicology, Virginia Commonwealth University, Richmond, VA, 23298, USA.
- Virginia Institute for Psychiatric and Behavioral Genetics Department of Psychiatry, Virginia Commonwealth University, Richmond, VA, 23298, USA.
| | - A Jackson
- Department of Pharmacology/Toxicology, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - P P Maldoon
- Department of Pharmacology/Toxicology, Virginia Commonwealth University, Richmond, VA, 23298, USA
| | - M I Damaj
- Department of Pharmacology/Toxicology, Virginia Commonwealth University, Richmond, VA, 23298, USA
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195
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Kahlson MA, Colodner KJ. Glial Tau Pathology in Tauopathies: Functional Consequences. J Exp Neurosci 2016; 9:43-50. [PMID: 26884683 PMCID: PMC4750898 DOI: 10.4137/jen.s25515] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 12/21/2015] [Accepted: 12/29/2015] [Indexed: 12/22/2022] Open
Abstract
Tauopathies are a class of neurodegenerative diseases characterized by the presence of hyperphosphorylated and aggregated tau pathology in neuronal and glial cells. Though the ratio of neuronal and glial tau aggregates varies across diseases, glial tau aggregates can populate the same degenerating brain regions as neuronal tau aggregates. While much is known about the deleterious consequences of tau pathology in neurons, the relative contribution of glial tau pathology to these diseases is less clear. Recent studies using a number of model systems implicate glial tau pathology in contributing to tauopathy pathogenesis. This review aims to highlight the functional consequences of tau overexpression in glial cells and explore the potential contribution of glial tau pathology in the pathogenesis of neurodegenerative tauopathies.
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Affiliation(s)
- Martha A Kahlson
- Department of Neuroscience and Behavior, Mount Holyoke College, South Hadley, MA, USA
| | - Kenneth J Colodner
- Department of Neuroscience and Behavior, Mount Holyoke College, South Hadley, MA, USA
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196
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Neuron-Glia Interactions in Neural Plasticity: Contributions of Neural Extracellular Matrix and Perineuronal Nets. Neural Plast 2016; 2016:5214961. [PMID: 26881114 PMCID: PMC4736403 DOI: 10.1155/2016/5214961] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/10/2015] [Indexed: 11/17/2022] Open
Abstract
Synapses are specialized structures that mediate rapid and efficient signal transmission between neurons and are surrounded by glial cells. Astrocytes develop an intimate association with synapses in the central nervous system (CNS) and contribute to the regulation of ion and neurotransmitter concentrations. Together with neurons, they shape intercellular space to provide a stable milieu for neuronal activity. Extracellular matrix (ECM) components are synthesized by both neurons and astrocytes and play an important role in the formation, maintenance, and function of synapses in the CNS. The components of the ECM have been detected near glial processes, which abut onto the CNS synaptic unit, where they are part of the specialized macromolecular assemblies, termed perineuronal nets (PNNs). PNNs have originally been discovered by Golgi and represent a molecular scaffold deposited in the interface between the astrocyte and subsets of neurons in the vicinity of the synapse. Recent reports strongly suggest that PNNs are tightly involved in the regulation of synaptic plasticity. Moreover, several studies have implicated PNNs and the neural ECM in neuropsychiatric diseases. Here, we highlight current concepts relating to neural ECM and PNNs and describe an in vitro approach that allows for the investigation of ECM functions for synaptogenesis.
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197
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Gao Y, Broussard J, Haque A, Revzin A, Lin T. Functional imaging of neuron-astrocyte interactions in a compartmentalized microfluidic device. MICROSYSTEMS & NANOENGINEERING 2016; 2:15045. [PMID: 31057811 PMCID: PMC6444726 DOI: 10.1038/micronano.2015.45] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/18/2015] [Accepted: 11/23/2015] [Indexed: 05/03/2023]
Abstract
Traditional approaches in cultivating neural cells in a dish without orienting their interactions have had only limited success in revealing neural network properties. To enhance the experimental capabilities of studying neural circuitry in vitro, we designed an experimental system combining concepts of micropatterned surfaces, microfluidic devices and genetically encoded biosensors. Micropatterning was used to position neurons and astrocytes in defined locations and guide interactions between the two cell types. Microfluidic chambers were placed atop micropatterned surfaces to allow delivery of different pharmacological agents or viral vectors to the desired cell types. In this device, astrocytes and neurons communicated through grooves molded into the floor of the microfluidic device. By combining microfluidics with genetically encoded calcium indicators as functional readouts, we further demonstrated the utility of this device for analyzing neuron-neuron and neuron-astrocyte interactions in vitro under both healthy and pathophysiological conditions. We found that both spontaneous and evoked calcium dynamics in astrocytes can be modulated by interactions with neurons. In the future, we foresee employing the microdevices described here for studying mechanisms of neurological disorders.
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Affiliation(s)
- Yandong Gao
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - Joey Broussard
- Department of Biochemistry and Molecular Medicine, University of California, Davis, CA 95616, USA
| | - Amranul Haque
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
| | - Alexander Revzin
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
- ()
| | - Tian Lin
- Department of Biochemistry and Molecular Medicine, University of California, Davis, CA 95616, USA
- ()
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198
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199
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Li Y, Li D, Raisman G. Astrocytic role in synapse formation after injury. Brain Res 2015; 1645:18-21. [PMID: 26746338 DOI: 10.1016/j.brainres.2015.12.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 12/19/2015] [Indexed: 01/24/2023]
Abstract
In 1969 a paper entitled Neuronal plasticity in the septal nuclei of the adult rat proposed that new synapses are formed in the adult brain after injury (Raisman, 1969). The quantitative electron microscopic study of the timed responses to selective partial denervation of the neuropil of the adult rat septal nuclei after distant transection of the hippocampal efferent axons in the fimbria showed that the new synapses arise by sprouting of surviving adjacent synapses which selectively take over the previously denervated sites and thus restore the number of synapses to normal. This article presents the evidence for the role of perisynaptic astrocytic processes in the removal and formation of synapses and considers its significance as one of the three major divisions of the astrocytic surface in terms of the axonal responses to injury and regeneration. This article is part of a Special Issue entitled SI:50th Anniversary Issue.
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Affiliation(s)
- Ying Li
- Spinal Repair Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom.
| | - Daqing Li
- Spinal Repair Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom.
| | - Geoffrey Raisman
- Spinal Repair Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom.
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200
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Croft W, Reusch K, Tilunaite A, Russell NA, Thul R, Bellamy TC. Probabilistic encoding of stimulus strength in astrocyte global calcium signals. Glia 2015; 64:537-52. [PMID: 26651126 DOI: 10.1002/glia.22947] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 11/16/2015] [Indexed: 12/21/2022]
Abstract
Astrocyte calcium signals can range in size from subcellular microdomains to waves that spread through the whole cell (and into connected cells). The differential roles of such local or global calcium signaling are under intense investigation, but the mechanisms by which local signals evolve into global signals in astrocytes are not well understood, nor are the computational rules by which physiological stimuli are transduced into a global signal. To investigate these questions, we transiently applied receptor agonists linked to calcium signaling to primary cultures of cerebellar astrocytes. Astrocytes repetitively tested with the same stimulus responded with global signals intermittently, indicating that each stimulus had a defined probability for triggering a response. The response probability varied between agonists, increased with agonist concentration, and could be positively and negatively modulated by crosstalk with other signaling pathways. To better understand the processes determining the evolution of a global signal, we recorded subcellular calcium "puffs" throughout the whole cell during stimulation. The key requirement for puffs to trigger a global calcium wave following receptor activation appeared to be the synchronous release of calcium from three or more sites, rather than an increasing calcium load accumulating in the cytosol due to increased puff size, amplitude, or frequency. These results suggest that the concentration of transient stimuli will be encoded into a probability of generating a global calcium response, determined by the likelihood of synchronous release from multiple subcellular sites.
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Affiliation(s)
- Wayne Croft
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Katharina Reusch
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom.,Department of Electrical and Electronic Engineering, University of Nottingham, Nottingham, United Kingdom
| | - Agne Tilunaite
- School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Noah A Russell
- Department of Electrical and Electronic Engineering, University of Nottingham, Nottingham, United Kingdom
| | - Rüdiger Thul
- School of Mathematical Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Tomas C Bellamy
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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