1
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Escalada P, Ezkurdia A, Ramírez MJ, Solas M. Essential Role of Astrocytes in Learning and Memory. Int J Mol Sci 2024; 25:1899. [PMID: 38339177 PMCID: PMC10856373 DOI: 10.3390/ijms25031899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/12/2024] Open
Abstract
One of the most biologically relevant functions of astrocytes within the CNS is the regulation of synaptic transmission, i.e., the physiological basis for information transmission between neurons. Changes in the strength of synaptic connections are indeed thought to be the cellular basis of learning and memory. Importantly, astrocytes have been demonstrated to tightly regulate these processes via the release of several gliotransmitters linked to astrocytic calcium activity as well as astrocyte-neuron metabolic coupling. Therefore, astrocytes seem to be integrators of and actors upon learning- and memory-relevant information. In this review, we focus on the role of astrocytes in learning and memory processes. We delineate the recognized inputs and outputs of astrocytes and explore the influence of manipulating astrocytes on behaviour across diverse learning paradigms. We conclude that astrocytes influence learning and memory in various manners. Appropriate astrocytic Ca2+ dynamics are being increasingly identified as central contributors to memory formation and retrieval. In addition, astrocytes regulate brain rhythms essential for cognition, and astrocyte-neuron metabolic cooperation is required for memory consolidation.
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Affiliation(s)
- Paula Escalada
- Department of Pharmaceutical Sciences, University of Navarra, 31008 Pamplona, Spain; (P.E.); (A.E.); (M.J.R.)
| | - Amaia Ezkurdia
- Department of Pharmaceutical Sciences, University of Navarra, 31008 Pamplona, Spain; (P.E.); (A.E.); (M.J.R.)
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
| | - María Javier Ramírez
- Department of Pharmaceutical Sciences, University of Navarra, 31008 Pamplona, Spain; (P.E.); (A.E.); (M.J.R.)
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
| | - Maite Solas
- Department of Pharmaceutical Sciences, University of Navarra, 31008 Pamplona, Spain; (P.E.); (A.E.); (M.J.R.)
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
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2
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Lee SH, Mak A, Verheijen MHG. Comparative assessment of the effects of DREADDs and endogenously expressed GPCRs in hippocampal astrocytes on synaptic activity and memory. Front Cell Neurosci 2023; 17:1159756. [PMID: 37051110 PMCID: PMC10083367 DOI: 10.3389/fncel.2023.1159756] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 03/13/2023] [Indexed: 03/29/2023] Open
Abstract
Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) have proven themselves as one of the key in vivo techniques of modern neuroscience, allowing for unprecedented access to cellular manipulations in living animals. With respect to astrocyte research, DREADDs have become a popular method to examine the functional aspects of astrocyte activity, particularly G-protein coupled receptor (GPCR)-mediated intracellular calcium (Ca2+) and cyclic adenosine monophosphate (cAMP) dynamics. With this method it has become possible to directly link the physiological aspects of astrocytic function to cognitive processes such as memory. As a result, a multitude of studies have explored the impact of DREADD activation in astrocytes on synaptic activity and memory. However, the emergence of varying results prompts us to reconsider the degree to which DREADDs expressed in astrocytes accurately mimic endogenous GPCR activity. Here we compare the major downstream signaling mechanisms, synaptic, and behavioral effects of stimulating Gq-, Gs-, and Gi-DREADDs in hippocampal astrocytes of adult mice to those of endogenously expressed GPCRs.
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Affiliation(s)
- Sophie H. Lee
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- Research Master’s Programme Brain and Cognitive Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Aline Mak
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Mark H. G. Verheijen
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- *Correspondence: Mark Verheijen,
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3
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Dai R, Yu T, Weng D, Li H, Cui Y, Wu Z, Guo Q, Zou H, Wu W, Gao X, Qi Z, Ren Y, Wang S, Li Y, Luo M. A neuropsin-based optogenetic tool for precise control of G q signaling. SCIENCE CHINA. LIFE SCIENCES 2022; 65:1271-1284. [PMID: 35579776 DOI: 10.1007/s11427-022-2122-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 04/29/2022] [Indexed: 06/15/2023]
Abstract
Gq-coupled receptors regulate numerous physiological processes by activating enzymes and inducing intracellular Ca2+ signals. There is a strong need for an optogenetic tool that enables powerful experimental control over Gq signaling. Here, we present chicken opsin 5 (cOpn5) as the long sought-after, single-component optogenetic tool that mediates ultra-sensitive optical control of intracellular Gq signaling with high temporal and spatial resolution. Expressing cOpn5 in HEK 293T cells and primary mouse astrocytes enables blue light-triggered, Gq-dependent Ca2+ release from intracellular stores and protein kinase C activation. Strong Ca2+ transients were evoked by brief light pulses of merely 10 ms duration and at 3 orders lower light intensity of that for common optogenetic tools. Photostimulation of cOpn5-expressing cells at the subcellular and single-cell levels generated fast intracellular Ca2+ transition, thus demonstrating the high spatial precision of cOpn5 optogenetics. The cOpn5-mediated optogenetics could also be applied to activate neurons and control animal behavior in a circuit-dependent manner. cOpn5 optogenetics may find broad applications in studying the mechanisms and functional relevance of Gq signaling in both non-excitable cells and excitable cells in all major organ systems.
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Affiliation(s)
- Ruicheng Dai
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
- School of Life Sciences, Peking University, Beijing, 100871, China
- Peking University-Tsinghua University-NIBS Joint Graduate Program, NIBS, Beijing, 102206, China
| | - Tao Yu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
- Peking University-Tsinghua University-NIBS Joint Graduate Program, NIBS, Beijing, 102206, China
| | - Danwei Weng
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
- Graduate School of Peking Union Medical College, Beijing, 100730, China
| | - Heng Li
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research (TIMBR), Beijing, 102206, China
| | - Yuting Cui
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Zhaofa Wu
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, 100871, China
- PKU-McGovern Institute for Brain Research, Beijing, 100871, China
| | - Qingchun Guo
- Chinese Institute for Brain Research, Beijing, 102206, China
- Capital Medical University, Beijing, 102206, China
| | - Haiyue Zou
- Chinese Institute for Brain Research, Beijing, 102206, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Wenting Wu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
- Peking University-Tsinghua University-NIBS Joint Graduate Program, NIBS, Beijing, 102206, China
| | - Xinwei Gao
- Chinese Institute for Brain Research, Beijing, 102206, China
| | - Zhongyang Qi
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Yuqi Ren
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Shu Wang
- Chinese Institute for Brain Research, Beijing, 102206, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, 100871, China
- PKU-McGovern Institute for Brain Research, Beijing, 100871, China
| | - Minmin Luo
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China.
- Graduate School of Peking Union Medical College, Beijing, 100730, China.
- Chinese Institute for Brain Research, Beijing, 102206, China.
- Tsinghua Institute of Multidisciplinary Biomedical Research (TIMBR), Beijing, 102206, China.
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4
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Akther S, Hirase H. Assessment of astrocytes as a mediator of memory and learning in rodents. Glia 2021; 70:1484-1505. [PMID: 34582594 DOI: 10.1002/glia.24099] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/15/2021] [Accepted: 09/16/2021] [Indexed: 12/26/2022]
Abstract
The classical view of astrocytes is that they provide supportive functions for neurons, transporting metabolites and maintaining the homeostasis of the extracellular milieu. This view is gradually changing with the advent of molecular genetics and optical methods allowing interrogation of selected cell types in live experimental animals. An emerging view that astrocytes additionally act as a mediator of synaptic plasticity and contribute to learning processes has gained in vitro and in vivo experimental support. Here we focus on the literature published in the past two decades to review the roles of astrocytes in brain plasticity in rodents, whereby the roles of neurotransmitters and neuromodulators are considered to be comparable to those in humans. We outline established inputs and outputs of astrocytes and discuss how manipulations of astrocytes have impacted the behavior in various learning paradigms. Multiple studies suggest that the contribution of astrocytes has a considerably longer time course than neuronal activation, indicating metabolic roles of astrocytes. We advocate that exploring upstream and downstream mechanisms of astrocytic activation will further provide insight into brain plasticity and memory/learning impairment.
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Affiliation(s)
- Sonam Akther
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hajime Hirase
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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5
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Malchow RP, Tchernookova BK, Choi JIV, Smith PJS, Kramer RH, Kreitzer MA. Review and Hypothesis: A Potential Common Link Between Glial Cells, Calcium Changes, Modulation of Synaptic Transmission, Spreading Depression, Migraine, and Epilepsy-H . Front Cell Neurosci 2021; 15:693095. [PMID: 34539347 PMCID: PMC8446203 DOI: 10.3389/fncel.2021.693095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 06/25/2021] [Indexed: 01/03/2023] Open
Abstract
There is significant evidence to support the notion that glial cells can modulate the strength of synaptic connections between nerve cells, and it has further been suggested that alterations in intracellular calcium are likely to play a key role in this process. However, the molecular mechanism(s) by which glial cells modulate neuronal signaling remains contentiously debated. Recent experiments have suggested that alterations in extracellular H+ efflux initiated by extracellular ATP may play a key role in the modulation of synaptic strength by radial glial cells in the retina and astrocytes throughout the brain. ATP-elicited alterations in H+ flux from radial glial cells were first detected from Müller cells enzymatically dissociated from the retina of tiger salamander using self-referencing H+-selective microelectrodes. The ATP-elicited alteration in H+ efflux was further found to be highly evolutionarily conserved, extending to Müller cells isolated from species as diverse as lamprey, skate, rat, mouse, monkey and human. More recently, self-referencing H+-selective electrodes have been used to detect ATP-elicited alterations in H+ efflux around individual mammalian astrocytes from the cortex and hippocampus. Tied to increases in intracellular calcium, these ATP-induced extracellular acidifications are well-positioned to be key mediators of synaptic modulation. In this article, we examine the evidence supporting H+ as a key modulator of neurotransmission, review data showing that extracellular ATP elicits an increase in H+ efflux from glial cells, and describe the potential signal transduction pathways involved in glial cell-mediated H+ efflux. We then examine the potential role that extracellular H+ released by glia might play in regulating synaptic transmission within the vertebrate retina, and then expand the focus to discuss potential roles in spreading depression, migraine, epilepsy, and alterations in brain rhythms, and suggest that alterations in extracellular H+ may be a unifying feature linking these disparate phenomena.
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Affiliation(s)
- Robert Paul Malchow
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, United States
| | - Boriana K. Tchernookova
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States
| | - Ji-in Vivien Choi
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States
- Stritch School of Medicine, Loyola University, Maywood, IL, United States
| | - Peter J. S. Smith
- Institute for Life Sciences, University of Southampton, Highfield Campus, Southampton, United Kingdom
- Bell Center, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Richard H. Kramer
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Matthew A. Kreitzer
- Department of Biology, Indiana Wesleyan University, Marion, IN, United States
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6
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Nanclares C, Baraibar AM, Araque A, Kofuji P. Dysregulation of Astrocyte-Neuronal Communication in Alzheimer's Disease. Int J Mol Sci 2021; 22:7887. [PMID: 34360652 PMCID: PMC8346080 DOI: 10.3390/ijms22157887] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 12/16/2022] Open
Abstract
Recent studies implicate astrocytes in Alzheimer's disease (AD); however, their role in pathogenesis is poorly understood. Astrocytes have well-established functions in supportive functions such as extracellular ionic homeostasis, structural support, and neurovascular coupling. However, emerging research on astrocytic function in the healthy brain also indicates their role in regulating synaptic plasticity and neuronal excitability via the release of neuroactive substances named gliotransmitters. Here, we review how this "active" role of astrocytes at synapses could contribute to synaptic and neuronal network dysfunction and cognitive impairment in AD.
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Affiliation(s)
| | | | | | - Paulo Kofuji
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA; (C.N.); (A.M.B.); (A.A.)
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7
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Choi JIV, Tchernookova BK, Kumar W, Kiedrowski L, Goeke C, Guizzetti M, Larson J, Kreitzer MA, Malchow RP. Extracellular ATP-Induced Alterations in Extracellular H + Fluxes From Cultured Cortical and Hippocampal Astrocytes. Front Cell Neurosci 2021; 15:640217. [PMID: 33994945 PMCID: PMC8120152 DOI: 10.3389/fncel.2021.640217] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 03/19/2021] [Indexed: 12/18/2022] Open
Abstract
Small alterations in the level of extracellular H+ can profoundly alter neuronal activity throughout the nervous system. In this study, self-referencing H+-selective microelectrodes were used to examine extracellular H+ fluxes from individual astrocytes. Activation of astrocytes cultured from mouse hippocampus and rat cortex with extracellular ATP produced a pronounced increase in extracellular H+ flux. The ATP-elicited increase in H+ flux appeared to be independent of bicarbonate transport, as ATP increased H+ flux regardless of whether the primary extracellular pH buffer was 26 mM bicarbonate or 1 mM HEPES, and persisted when atmospheric levels of CO2 were replaced by oxygen. Adenosine failed to elicit any change in extracellular H+ fluxes, and ATP-mediated increases in H+ flux were inhibited by the P2 inhibitors suramin and PPADS suggesting direct activation of ATP receptors. Extracellular ATP also induced an intracellular rise in calcium in cultured astrocytes, and ATP-induced rises in both calcium and H+ efflux were significantly attenuated when calcium re-loading into the endoplasmic reticulum was inhibited by thapsigargin. Replacement of extracellular sodium with choline did not significantly reduce the size of the ATP-induced increases in H+ flux, and the increases in H+ flux were not significantly affected by addition of EIPA, suggesting little involvement of Na+/H+ exchangers in ATP-elicited increases in H+ flux. Given the high sensitivity of voltage-sensitive calcium channels on neurons to small changes in levels of free H+, we hypothesize that the ATP-mediated extrusion of H+ from astrocytes may play a key role in regulating signaling at synapses within the nervous system.
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Affiliation(s)
- Ji-In Vivien Choi
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States.,Stritch School of Medicine, Loyola University, Maywood, IL, United States
| | - Boriana K Tchernookova
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States
| | - Wasan Kumar
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States
| | - Lech Kiedrowski
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States.,Spot Cells LLC, Chicago, IL, United States
| | - Calla Goeke
- VA Portland Health Care System, Portland, OR, United States.,Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, United States
| | - Marina Guizzetti
- VA Portland Health Care System, Portland, OR, United States.,Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, United States
| | - John Larson
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States
| | - Matthew A Kreitzer
- Department of Biology, Indiana Wesleyan University, Marion, IN, United States
| | - Robert Paul Malchow
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States.,Department Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, United States
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8
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Nwachukwu KN, Evans WA, Sides TR, Trevisani CP, Davis A, Marshall SA. Chemogenetic manipulation of astrocytic signaling in the basolateral amygdala reduces binge-like alcohol consumption in male mice. J Neurosci Res 2021; 99:1957-1972. [PMID: 33844860 DOI: 10.1002/jnr.24841] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/21/2021] [Indexed: 12/18/2022]
Abstract
Binge drinking is a common occurrence in the United States, but a high concentration of alcohol in the blood has been shown to have reinforcing and reciprocal effects on the neuroimmune system in both dependent and non-dependent scenarios. The first part of this study examined alcohol's effects on the astrocytic response in the central amygdala and basolateral amygdala (BLA) in a non-dependent model. C57BL/6J mice were given access to either ethanol, water, or sucrose during a "drinking in the dark" paradigm, and astrocyte number and astrogliosis were measured using immunohistochemistry. Results indicate that non-dependent consumption increased glial fibrillary acidic protein (GFAP) density but not the number of GFAP+ cells, suggesting that non-dependent ethanol is sufficient to elicit astrocyte activation. The second part of this study examined how astrocytes impacted behaviors and the neurochemistry related to alcohol using the chemogenetic tool, DREADDs (designer receptors exclusively activated by designer drugs). Transgenic GFAP-hM3Dq mice were administered clozapine N-oxide both peripherally, affecting the entire central nervous system (CNS), or directly into the BLA. In both instances, GFAP-Gq-signaling activation significantly reduced ethanol consumption and correlating blood ethanol concentrations. However, GFAP-Gq-DREADD activation throughout the CNS had more broad effects resulting in decreased locomotor activity and sucrose consumption. More targeted GFAP-Gq-signaling activation in the BLA only impacted ethanol consumption. Finally, a glutamate assay revealed that after GFAP-Gq-signaling activation glutamate concentrations in the amygdala were partially normalized to control levels. Altogether, these studies support the theory that astrocytes represent a viable target for alcohol use disorder therapies.
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Affiliation(s)
- Kala N Nwachukwu
- Department of Biological & Biomedical Sciences, North Carolina Central University, Durham, NC, USA
| | - William A Evans
- Department of Basic Pharmaceutical Sciences, Fred P. Wilson School of Pharmacy, High Point University, High Point, NC, USA
| | - Tori R Sides
- Department of Biological & Biomedical Sciences, North Carolina Central University, Durham, NC, USA
| | - Christopher P Trevisani
- Department of Basic Pharmaceutical Sciences, Fred P. Wilson School of Pharmacy, High Point University, High Point, NC, USA
| | - Ambryia Davis
- Department of Basic Pharmaceutical Sciences, Fred P. Wilson School of Pharmacy, High Point University, High Point, NC, USA
| | - S Alex Marshall
- Department of Biological & Biomedical Sciences, North Carolina Central University, Durham, NC, USA.,Department of Basic Pharmaceutical Sciences, Fred P. Wilson School of Pharmacy, High Point University, High Point, NC, USA.,Department of Psychology & Neuroscience, University of North Carolina-Chapel Hill, Chapel Hill, NC, USA
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9
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Slc1a3-2A-CreERT2 mice reveal unique features of Bergmann glia and augment a growing collection of Cre drivers and effectors in the 129S4 genetic background. Sci Rep 2021; 11:5412. [PMID: 33686166 PMCID: PMC7940647 DOI: 10.1038/s41598-021-84887-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 02/22/2021] [Indexed: 12/26/2022] Open
Abstract
Genetic variation is a primary determinant of phenotypic diversity. In laboratory mice, genetic variation can be a serious experimental confounder, and thus minimized through inbreeding. However, generalizations of results obtained with inbred strains must be made with caution, especially when working with complex phenotypes and disease models. Here we compared behavioral characteristics of C57Bl/6—the strain most widely used in biomedical research—with those of 129S4. In contrast to 129S4, C57Bl/6 demonstrated high within-strain and intra-litter behavioral hyperactivity. Although high consistency would be advantageous, the majority of disease models and transgenic tools are in C57Bl/6. We recently established six Cre driver lines and two Cre effector lines in 129S4. To augment this collection, we genetically engineered a Cre line to study astrocytes in 129S4. It was validated with two Cre effector lines: calcium indicator gCaMP5g-tdTomato and RiboTag—a tool widely used to study cell type-specific translatomes. These reporters are in different genomic loci, and in both the Cre was functional and astrocyte-specific. We found that calcium signals lasted longer and had a higher amplitude in cortical compared to hippocampal astrocytes, genes linked to a single neurodegenerative disease have highly divergent expression patterns, and that ribosome proteins are non-uniformly expressed across brain regions and cell types.
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10
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Wahis J, Holt MG. Astrocytes, Noradrenaline, α1-Adrenoreceptors, and Neuromodulation: Evidence and Unanswered Questions. Front Cell Neurosci 2021; 15:645691. [PMID: 33716677 PMCID: PMC7947346 DOI: 10.3389/fncel.2021.645691] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/03/2021] [Indexed: 12/27/2022] Open
Abstract
Noradrenaline is a major neuromodulator in the central nervous system (CNS). It is released from varicosities on neuronal efferents, which originate principally from the main noradrenergic nuclei of the brain - the locus coeruleus - and spread throughout the parenchyma. Noradrenaline is released in response to various stimuli and has complex physiological effects, in large part due to the wide diversity of noradrenergic receptors expressed in the brain, which trigger diverse signaling pathways. In general, however, its main effect on CNS function appears to be to increase arousal state. Although the effects of noradrenaline have been researched extensively, the majority of studies have assumed that noradrenaline exerts its effects by acting directly on neurons. However, neurons are not the only cells in the CNS expressing noradrenaline receptors. Astrocytes are responsive to a range of neuromodulators - including noradrenaline. In fact, noradrenaline evokes robust calcium transients in astrocytes across brain regions, through activation of α1-adrenoreceptors. Crucially, astrocytes ensheath neurons at synapses and are known to modulate synaptic activity. Hence, astrocytes are in a key position to relay, or amplify, the effects of noradrenaline on neurons, most notably by modulating inhibitory transmission. Based on a critical appraisal of the current literature, we use this review to argue that a better understanding of astrocyte-mediated noradrenaline signaling is therefore essential, if we are ever to fully understand CNS function. We discuss the emerging concept of astrocyte heterogeneity and speculate on how this might impact the noradrenergic modulation of neuronal circuits. Finally, we outline possible experimental strategies to clearly delineate the role(s) of astrocytes in noradrenergic signaling, and neuromodulation in general, highlighting the urgent need for more specific and flexible experimental tools.
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Affiliation(s)
- Jérôme Wahis
- Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
| | - Matthew G. Holt
- Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research, Leuven, Belgium
- Department of Neurosciences, KU Leuven, Leuven, Belgium
- Leuven Brain Institute, Leuven, Belgium
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11
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Salmina AB, Gorina YV, Erofeev AI, Balaban PM, Bezprozvanny IB, Vlasova OL. Optogenetic and chemogenetic modulation of astroglial secretory phenotype. Rev Neurosci 2021; 32:459-479. [PMID: 33550788 DOI: 10.1515/revneuro-2020-0119] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 11/28/2020] [Indexed: 12/20/2022]
Abstract
Astrocytes play a major role in brain function and alterations in astrocyte function that contribute to the pathogenesis of many brain disorders. The astrocytes are attractive cellular targets for neuroprotection and brain tissue regeneration. Development of novel approaches to monitor and to control astroglial function is of great importance for further progress in basic neurobiology and in clinical neurology, as well as psychiatry. Recently developed advanced optogenetic and chemogenetic techniques enable precise stimulation of astrocytes in vitro and in vivo, which can be achieved by the expression of light-sensitive channels and receptors, or by expression of receptors exclusively activated by designer drugs. Optogenetic stimulation of astrocytes leads to dramatic changes in intracellular calcium concentrations and causes the release of gliotransmitters. Optogenetic and chemogenetic protocols for astrocyte activation aid in extracting novel information regarding the function of brain's neurovascular unit. This review summarizes current data obtained by this approach and discusses a potential mechanistic connection between astrocyte stimulation and changes in brain physiology.
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Affiliation(s)
- Alla B Salmina
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
- Research Institute of Molecular Medicine and Pathobiochemistry, Prof. V.F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - Yana V Gorina
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
- Research Institute of Molecular Medicine and Pathobiochemistry, Prof. V.F. Voino-Yasenetsky Krasnoyarsk State Medical University, Krasnoyarsk, Russia
| | - Alexander I Erofeev
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Pavel M Balaban
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
- Laboratory of Cellular Neurobiology of Learning, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia
| | - Ilya B Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
| | - Olga L Vlasova
- Laboratory of Molecular Neurodegeneration, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
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12
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Charvériat M, Guiard BP. Serotonergic neurons in the treatment of mood disorders: The dialogue with astrocytes. PROGRESS IN BRAIN RESEARCH 2021; 259:197-228. [PMID: 33541677 DOI: 10.1016/bs.pbr.2021.01.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Astrocytes were traditionally regarded as cells important to neuronal activity, providing both metabolic and structural supports. Recent evidence suggests that they may also play a crucial role in the control of higher brain functions. In keeping with this hypothesis, it is now well accepted that astrocytes contribute to stress but also react to antidepressant drugs as they express serotonergic transporters and receptors. However, the downstream mechanisms leading to the fine-tuned regulation of mood are still unknown. This chapter pays attention to the role of astrocytes in the regulation of emotional behavior and related serotonergic neurotransmission. In particular, it gives a current state of the clinical and preclinical evidence showing that astrocytes respond to environmental conditions and antidepressant drugs through the release of gliotransmitters and neurotrophic factors which in turn, influence serotonergic tone in discrete brain areas. This state-of-the-art review aims at demonstrating the remarkable potential for novel therapeutic antidepressant strategies targeting these glial cells.
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Affiliation(s)
| | - Bruno P Guiard
- Centre de Recherches sur la Cognition Animale, Centre de Biologie Intégrative, Université de Toulouse, CNRS, Toulouse, France.
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13
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Nagai J, Yu X, Papouin T, Cheong E, Freeman MR, Monk KR, Hastings MH, Haydon PG, Rowitch D, Shaham S, Khakh BS. Behaviorally consequential astrocytic regulation of neural circuits. Neuron 2020; 109:576-596. [PMID: 33385325 DOI: 10.1016/j.neuron.2020.12.008] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
Astrocytes are a large and diverse population of morphologically complex cells that exist throughout nervous systems of multiple species. Progress over the last two decades has shown that astrocytes mediate developmental, physiological, and pathological processes. However, a long-standing open question is how astrocytes regulate neural circuits in ways that are behaviorally consequential. In this regard, we summarize recent studies using Caenorhabditis elegans, Drosophila melanogaster, Danio rerio, and Mus musculus. The data reveal diverse astrocyte mechanisms operating in seconds or much longer timescales within neural circuits and shaping multiple behavioral outputs. We also refer to human diseases that have a known primary astrocytic basis. We suggest that including astrocytes in mechanistic, theoretical, and computational studies of neural circuits provides new perspectives to understand behavior, its regulation, and its disease-related manifestations.
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Affiliation(s)
- Jun Nagai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; RIKEN Center for Brain Science, 2-1 Hirosawa Wako City, Saitama 351-0198, Japan
| | - Xinzhu Yu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 514 Burrill Hall, 407 S. Goodwin Ave, Urbana, IL 61801, USA
| | - Thomas Papouin
- Department of Neuroscience, Washington University in St. Louis, School of Medicine, Campus Box 8108, 660 South Euclid Ave., St. Louis, MO 63110, USA
| | - Eunji Cheong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
| | - Marc R Freeman
- The Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Kelly R Monk
- The Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Michael H Hastings
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Philip G Haydon
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - David Rowitch
- Department of Paediatrics, Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK; Departments of Pediatrics and Neurosurgery, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
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14
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das Neves SP, Sousa JC, Sousa N, Cerqueira JJ, Marques F. Altered astrocytic function in experimental neuroinflammation and multiple sclerosis. Glia 2020; 69:1341-1368. [PMID: 33247866 DOI: 10.1002/glia.23940] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/14/2020] [Accepted: 11/17/2020] [Indexed: 12/11/2022]
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) that affects about 2.5 million people worldwide. In MS, the patients' immune system starts to attack the myelin sheath, leading to demyelination, neurodegeneration, and, ultimately, loss of vital neurological functions such as walking. There is currently no cure for MS and the available treatments only slow the initial phases of the disease. The later-disease mechanisms are poorly understood and do not directly correlate with the activity of immune system cells, the main target of the available treatments. Instead, evidence suggests that disease progression and disability are better correlated with the maintenance of a persistent low-grade inflammation inside the CNS, driven by local glial cells, like astrocytes and microglia. Depending on the context, astrocytes can (a) exacerbate inflammation or (b) promote immunosuppression and tissue repair. In this review, we will address the present knowledge that exists regarding the role of astrocytes in MS and experimental animal models of the disease.
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Affiliation(s)
- Sofia Pereira das Neves
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - João Carlos Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal.,Clinical Academic Center, Braga, Portugal
| | - João José Cerqueira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal.,Clinical Academic Center, Braga, Portugal
| | - Fernanda Marques
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
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15
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Trujillo-Estrada L, Gomez-Arboledas A, Forner S, Martini AC, Gutierrez A, Baglietto-Vargas D, LaFerla FM. Astrocytes: From the Physiology to the Disease. Curr Alzheimer Res 2020; 16:675-698. [PMID: 31470787 DOI: 10.2174/1567205016666190830110152] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 04/12/2019] [Accepted: 05/17/2019] [Indexed: 12/14/2022]
Abstract
Astrocytes are key cells for adequate brain formation and regulation of cerebral blood flow as well as for the maintenance of neuronal metabolism, neurotransmitter synthesis and exocytosis, and synaptic transmission. Many of these functions are intrinsically related to neurodegeneration, allowing refocusing on the role of astrocytes in physiological and neurodegenerative states. Indeed, emerging evidence in the field indicates that abnormalities in the astrocytic function are involved in the pathogenesis of multiple neurodegenerative diseases, including Alzheimer's Disease (AD), Parkinson's Disease (PD), Huntington's Disease (HD) and Amyotrophic Lateral Sclerosis (ALS). In the present review, we highlight the physiological role of astrocytes in the CNS, including their communication with other cells in the brain. Furthermore, we discuss exciting findings and novel experimental approaches that elucidate the role of astrocytes in multiple neurological disorders.
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Affiliation(s)
- Laura Trujillo-Estrada
- Institute for Memory Impairments and Neurological Disorders (UCI MIND), University of California, Irvine, CA 92697-4545, United States
| | - Angela Gomez-Arboledas
- Department of Cell Biology, Genetic and Physiology, Faculty of Sciences, University of Malaga, Malaga, Spain.,Instituto de Investigación Biomédica de Malaga-IBIMA, Malaga, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Stefânia Forner
- Institute for Memory Impairments and Neurological Disorders (UCI MIND), University of California, Irvine, CA 92697-4545, United States
| | - Alessandra Cadete Martini
- Institute for Memory Impairments and Neurological Disorders (UCI MIND), University of California, Irvine, CA 92697-4545, United States
| | - Antonia Gutierrez
- Department of Cell Biology, Genetic and Physiology, Faculty of Sciences, University of Malaga, Malaga, Spain.,Instituto de Investigación Biomédica de Malaga-IBIMA, Malaga, Spain.,Networking Research Center on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - David Baglietto-Vargas
- Institute for Memory Impairments and Neurological Disorders (UCI MIND), University of California, Irvine, CA 92697-4545, United States.,Department of Neurobiology and Behavior, University of California, Irvine, CA 92697, United States
| | - Frank M LaFerla
- Institute for Memory Impairments and Neurological Disorders (UCI MIND), University of California, Irvine, CA 92697-4545, United States.,Department of Neurobiology and Behavior, University of California, Irvine, CA 92697, United States
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16
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Xie AX, Madayag A, Minton SK, McCarthy KD, Malykhina AP. Sensory satellite glial Gq-GPCR activation alleviates inflammatory pain via peripheral adenosine 1 receptor activation. Sci Rep 2020; 10:14181. [PMID: 32843670 PMCID: PMC7447794 DOI: 10.1038/s41598-020-71073-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 08/10/2020] [Indexed: 02/07/2023] Open
Abstract
Glial fibrillary acidic protein expressing (GFAP+) glia modulate nociceptive neuronal activity in both the peripheral nervous system (PNS) and the central nervous system (CNS). Resident GFAP+ glia in dorsal root ganglia (DRG) known as satellite glial cells (SGCs) potentiate neuronal activity by releasing pro-inflammatory cytokines and neuroactive compounds. In this study, we tested the hypothesis that SGC Gq-coupled receptor (Gq-GPCR) signaling modulates pain sensitivity in vivo using Gfap-hM3Dq mice. Complete Freund's adjuvant (CFA) was used to induce inflammatory pain, and mechanical sensitivity and thermal sensitivity were used to assess the neuromodulatory effect of glial Gq-GPCR activation in awake mice. Pharmacogenetic activation of Gq-GPCR signaling in sensory SGCs decreased heat-induced nociceptive responses and reversed inflammation-induced mechanical allodynia via peripheral adenosine A1 receptor activation. These data reveal a previously unexplored role of sensory SGCs in decreasing afferent excitability. The identified molecular mechanism underlying the analgesic role of SGCs offers new approaches for reversing peripheral nociceptive sensitization.
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MESH Headings
- Animals
- Benzilates/pharmacology
- Clozapine/analogs & derivatives
- Clozapine/pharmacology
- Freund's Adjuvant/toxicity
- GTP-Binding Protein alpha Subunits, Gq-G11/physiology
- Genes, Synthetic
- Hot Temperature
- Hyperalgesia/physiopathology
- Hyperalgesia/prevention & control
- Inflammation/chemically induced
- Inflammation/physiopathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Muscarinic Agonists/pharmacology
- Neuroglia/enzymology
- Neuroglia/physiology
- Nociception/physiology
- Nortropanes/pharmacology
- Promoter Regions, Genetic
- Purinergic P1 Receptor Agonists/pharmacology
- Purinergic P1 Receptor Antagonists/pharmacology
- Receptor, Adenosine A1/drug effects
- Receptor, Adenosine A1/physiology
- Receptor, Muscarinic M3/drug effects
- Receptor, Muscarinic M3/genetics
- Receptor, Muscarinic M3/physiology
- Receptors, G-Protein-Coupled
- Recombinant Fusion Proteins/drug effects
- Recombinant Fusion Proteins/metabolism
- Theophylline/analogs & derivatives
- Theophylline/pharmacology
- Touch
- Xanthines/pharmacology
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Affiliation(s)
- Alison Xiaoqiao Xie
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill (UNC-CH), Chapel Hill, USA.
- Division of Urology, Department of Surgery, University of Colorado Denver (UCD), Anschutz Medical Campus (AMC), 12700E 19th Ave., Room 6440D, Mail stop C317, Aurora, CO, 80045, USA.
- Department of Surgery, UCD-AMC, Aurora, CO, USA.
| | - Aric Madayag
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill (UNC-CH), Chapel Hill, USA
- NeuroCycle Therapeutics, Inc., 3829 N Cramer St., Shorewood, WI, 53211, USA
| | - Suzanne K Minton
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill (UNC-CH), Chapel Hill, USA
- Certara, 5511 Capital Center Drive, Ste. 204, Raleigh, NC, 27606, USA
| | - Ken D McCarthy
- Professor Emeritus in the Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, 120 Mason Farm Road, 4010 Genetic Medicine Bldg, Campus Box 7365, Chapel Hill, NC, 27599-7365, USA
| | - Anna P Malykhina
- Division of Urology, Department of Surgery, University of Colorado Denver (UCD), Anschutz Medical Campus (AMC), 12700E 19th Ave., Room 6440D, Mail stop C317, Aurora, CO, 80045, USA
- Department of Physiology and Biophysics, University of Colorado School of Medicine, 12700 East 19th Ave., Rm 6001, Mail Stop C317, Aurora, CO, 80045, USA
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17
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Melanopsin for Time-Controlling Activation of Astrocyte -Neuron Networks. Methods Mol Biol 2020. [PMID: 32651909 DOI: 10.1007/978-1-0716-0755-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Melanopsin, a mammalian G-protein-coupled photopigment, is a novel optical tool which enables studying astrocyte-neuron networks. Here, we describe the required guidelines to take advantage of this promising optical tool for functional neuron-glia studies. The selective expression of melanopsin in astrocytes allows triggering astrocytic Ca2+ signaling, changes in synaptic transmission, and modifying behavioral responses.
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18
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Hippocampal astrocyte dysfunction contributes to etomidate-induced long-lasting synaptic inhibition. Biochem Biophys Res Commun 2019; 519:803-811. [DOI: 10.1016/j.bbrc.2019.09.053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 09/12/2019] [Indexed: 11/24/2022]
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19
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Siemsen BM, Reichel CM, Leong KC, Garcia-Keller C, Gipson CD, Spencer S, McFaddin JA, Hooker KN, Kalivas PW, Scofield MD. Effects of Methamphetamine Self-Administration and Extinction on Astrocyte Structure and Function in the Nucleus Accumbens Core. Neuroscience 2019; 406:528-541. [PMID: 30926546 PMCID: PMC6545487 DOI: 10.1016/j.neuroscience.2019.03.040] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 03/15/2019] [Accepted: 03/19/2019] [Indexed: 01/01/2023]
Abstract
Astrocytes provide support for neurons, regulate metabolic processes, and influence neuronal communication in a variety of ways, including through the homeostatic regulation of glutamate. Following 2-h cocaine or methamphetamine self-administration (SA) and extinction, rodents display decreased levels of basal glutamate in the nucleus accumbens core (NAcore), which transitions to elevated glutamate levels during drug seeking. We hypothesized that, like cocaine, this glutamate 'overflow' during methamphetamine seeking arises via decreased expression of the astroglial glutamate transporter GLT-1, and withdrawal of perisynaptic astroglial processes (PAPs) from synapses. As expected, methamphetamine self-administration and extinction decreased the level of contact made by PAPs in the NAcore, yet did not impact glutamate uptake, GLT-1 expression, or the general structural characteristics of astrocytes. Interestingly, systemic administration of N-acetylcysteine (NAC), a drug that both upregulates GLT-1 and promotes glial-glutamate release, reduced cued methamphetamine seeking. In order to test the impact of astrocyte activation and the induction of glial glutamate release within the NAcore, we employed astrocyte-specific expression of designer receptors exclusively activated by designer drugs (DREADDs). We show here that acute activation of Gq-coupled DREADDs in this region inhibited cued methamphetamine seeking. Taken together, these data indicate that cued methamphetamine seeking following two-hour SA is not mediated by deficient glutamate clearance in the NAcore, yet can be inhibited by engaging NAcore astrocytes.
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Affiliation(s)
- B M Siemsen
- Department of Anesthesiology and Perioperative Medicine, Medical University of South Carolina, Charleston, SC, USA; Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - C M Reichel
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - K C Leong
- Department of Psychology, Trinity University, San Antonio, TX, USA
| | - C Garcia-Keller
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - C D Gipson
- Department of Psychology, Arizona State University, Tempe, AZ, USA
| | - S Spencer
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, USA
| | - J A McFaddin
- Department of Anesthesiology and Perioperative Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - K N Hooker
- Department of Anesthesiology and Perioperative Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - P W Kalivas
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - M D Scofield
- Department of Anesthesiology and Perioperative Medicine, Medical University of South Carolina, Charleston, SC, USA; Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.
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20
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Mederos S, Hernández-Vivanco A, Ramírez-Franco J, Martín-Fernández M, Navarrete M, Yang A, Boyden ES, Perea G. Melanopsin for precise optogenetic activation of astrocyte-neuron networks. Glia 2019; 67:915-934. [PMID: 30632636 DOI: 10.1002/glia.23580] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/28/2018] [Accepted: 11/30/2018] [Indexed: 12/11/2022]
Abstract
Optogenetics has been widely expanded to enhance or suppress neuronal activity and it has been recently applied to glial cells. Here, we have used a new approach based on selective expression of melanopsin, a G-protein-coupled photopigment, in astrocytes to trigger Ca2+ signaling. Using the genetically encoded Ca2+ indicator GCaMP6f and two-photon imaging, we show that melanopsin is both competent to stimulate robust IP3-dependent Ca2+ signals in astrocyte fine processes, and to evoke an ATP/Adenosine-dependent transient boost of hippocampal excitatory synaptic transmission. Additionally, under low-frequency light stimulation conditions, melanopsin-transfected astrocytes can trigger long-term synaptic changes. In vivo, melanopsin-astrocyte activation enhances episodic-like memory, suggesting melanopsin as an optical tool that could recapitulate the wide range of regulatory actions of astrocytes on neuronal networks in behaving animals. These results describe a novel approach using melanopsin as a precise trigger for astrocytes that mimics their endogenous G-protein signaling pathways, and present melanopsin as a valuable optical tool for neuron-glia studies.
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Affiliation(s)
- Sara Mederos
- Department of Functional and Systems Neurobiology, Instituto Cajal, CSIC, Madrid, Spain
| | | | - Jorge Ramírez-Franco
- Department of Functional and Systems Neurobiology, Instituto Cajal, CSIC, Madrid, Spain
| | | | - Marta Navarrete
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
| | - Aimei Yang
- Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Edward S Boyden
- Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts.,McGovern Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Gertrudis Perea
- Department of Functional and Systems Neurobiology, Instituto Cajal, CSIC, Madrid, Spain
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21
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22
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Rakers C, Schleif M, Blank N, Matušková H, Ulas T, Händler K, Torres SV, Schumacher T, Tai K, Schultze JL, Jackson WS, Petzold GC. Stroke target identification guided by astrocyte transcriptome analysis. Glia 2018; 67:619-633. [DOI: 10.1002/glia.23544] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 08/28/2018] [Accepted: 08/29/2018] [Indexed: 12/19/2022]
Affiliation(s)
- Cordula Rakers
- German Center for Neurodegenerative Diseases (DZNE); Bonn Germany
| | - Melvin Schleif
- German Center for Neurodegenerative Diseases (DZNE); Bonn Germany
| | - Nelli Blank
- German Center for Neurodegenerative Diseases (DZNE); Bonn Germany
| | - Hana Matušková
- German Center for Neurodegenerative Diseases (DZNE); Bonn Germany
- Department of Neurology; University Hospital Bonn; Bonn Germany
| | - Thomas Ulas
- Genomics and Immunoregulation; LIMES-Institute, University of Bonn; Germany
| | - Kristian Händler
- Genomics and Immunoregulation; LIMES-Institute, University of Bonn; Germany
| | | | - Toni Schumacher
- German Center for Neurodegenerative Diseases (DZNE); Bonn Germany
| | - Khalid Tai
- German Center for Neurodegenerative Diseases (DZNE); Bonn Germany
| | - Joachim L. Schultze
- German Center for Neurodegenerative Diseases (DZNE); Bonn Germany
- Genomics and Immunoregulation; LIMES-Institute, University of Bonn; Germany
| | | | - Gabor C. Petzold
- German Center for Neurodegenerative Diseases (DZNE); Bonn Germany
- Department of Neurology; University Hospital Bonn; Bonn Germany
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23
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Scofield MD. Exploring the Role of Astroglial Glutamate Release and Association With Synapses in Neuronal Function and Behavior. Biol Psychiatry 2018; 84:778-786. [PMID: 29258653 PMCID: PMC5948108 DOI: 10.1016/j.biopsych.2017.10.029] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 10/18/2017] [Accepted: 10/31/2017] [Indexed: 12/25/2022]
Abstract
Astrocytes are stellate cells whose appearance can resemble a pointed star, especially when visualizing glial fibrillary acidic protein, a canonical marker for astrocytes. Accordingly, there is a commonly made connection between the points of light that shine in the night sky and the diffuse and abundant cells that buffer ions and provide support for neurons. An exceptional amount of function has been attributed to, negated for, and potentially reaffirmed for these cells, especially regarding their ability to release neuroactive molecules and influence synaptic plasticity. This makes the precise role of astrocytes in tuning neural communication seem difficult to grasp. However, data from animal models of addiction demonstrate that a variety of drug-induced molecular adaptations responsible for relapse vulnerability take place in astrocyte systems that regulate glutamate uptake and release. These findings highlight astrocytes as a critical component of the neural systems responsible for addiction, serving as a key component of the plasticity responsible for relapse and drug seeking. Here I assemble recent findings that utilize genetic tools to selectively manipulate or measure flux of internal calcium in astrocytes, focusing on G protein-coupled receptor-mediated mobilization of calcium and the induction of glutamate release. Further, I compile evidence regarding astrocyte glutamate release as well as astrocyte association with synapses with respect to the impact of these cellular phenomena in shaping synaptic transmission. I also place these findings in the context of the previous studies of Scofield et al., who explored the role of astrocytes in the nucleus accumbens in the neural mechanisms underlying cocaine seeking.
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Affiliation(s)
- Michael D. Scofield
- Department of Anesthesiology and Perioperative Medicine, Medical University of South Carolina, Charleston, SC, 29425 USA,Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425 USA
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24
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Deemyad T, Lüthi J, Spruston N. Astrocytes integrate and drive action potential firing in inhibitory subnetworks. Nat Commun 2018; 9:4336. [PMID: 30337521 PMCID: PMC6194108 DOI: 10.1038/s41467-018-06338-3] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/27/2018] [Indexed: 12/29/2022] Open
Abstract
Many brain functions depend on the ability of neural networks to temporally integrate transient inputs to produce sustained discharges. This can occur through cell-autonomous mechanisms in individual neurons and through reverberating activity in recurrently connected neural networks. We report a third mechanism involving temporal integration of neural activity by a network of astrocytes. Previously, we showed that some types of interneurons can generate long-lasting trains of action potentials (barrage firing) following repeated depolarizing stimuli. Here we show that calcium signaling in an astrocytic network correlates with barrage firing; that active depolarization of astrocyte networks by chemical or optogenetic stimulation enhances; and that chelating internal calcium, inhibiting release from internal stores, or inhibiting GABA transporters or metabotropic glutamate receptors inhibits barrage firing. Thus, networks of astrocytes influence the spatiotemporal dynamics of neural networks by directly integrating neural activity and driving barrages of action potentials in some populations of inhibitory interneurons. Specific types of inhibitory neurons exhibit prolonged, high-frequency barrages of action potentials. Here, the authors show that astrocytes might mediate such barrage firing.
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Affiliation(s)
- Tara Deemyad
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA.,Department of Neurobiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Joel Lüthi
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA.,Institute of Molecular Life Sciences, University of Zürich, Zürich, 8057, Switzerland
| | - Nelson Spruston
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA.
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25
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Ganapathy K, Datta I, Bhonde R. Astrocyte-Like Cells Differentiated from Dental Pulp Stem Cells Protect Dopaminergic Neurons Against 6-Hydroxydopamine Toxicity. Mol Neurobiol 2018; 56:4395-4413. [PMID: 30327976 DOI: 10.1007/s12035-018-1367-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 09/25/2018] [Indexed: 12/20/2022]
Abstract
Dental pulp stem cells (DPSCs) are promising for use in neurodegenerative-diseases because of their neural crest origin. While neuronal differentiation of DPSCs has been shown, their plasticity towards astrocyte-like cells remains to be studied. We aimed to examine differentiation potential of DPSCs to astrocytes and their consequent neuroprotective role towards dopaminergic (DA) neurons under 6-hydroxydopamine (6-OHDA) toxicity. Induction of DPSCs to astrocytes with differentiation factors showed definitive increase in astrocyte-specific markers glial fibrillary acidic protein (GFAP), and excitatory amino acid transporter 2 along with glial calcium-binding protein S100β through FACS and immunofluorescence assays. RT-PCR and ELISA showed significant increase in BDNF and GDNF expression and secretion in astrocyte-differentiated DPSCs over naïve DPSCs. Neuroprotective role of these cells on DA neurons under 6-OHDA stress was evaluated by both contact and non-contact methods. FACS analysis of PKH26-stained SH-SY5Y homogenous cells in contact method and of TH immunopositive cells in primary midbrain culture in non-contact method both indicated higher survival of DA neurons in astrocyte-differentiated DPSCs over naïve DPSCs. Recovery of β-tubulin III and TH immunopositive cells was reduced in the presence of TrkB inhibitor, suggesting a key neuroprotective role of BDNF secretion by DPSCs. When nitric oxide (NO) release was inhibited by L-NAME in primary midbrain culture, BDNF release in co-culture under 6-OHDA stress reduced further in naïve DPSCs than in astrocyte-differentiated DPSCs, suggesting that BDNF release in naïve DPSCs is primarily regulated by paracrine signaling while for differentiated DPSCs, it is equally through autocrine and paracrine signaling with NO being the mediator. In conclusion, we suggest that DPSCs exposed to glial commitment cues exhibit substantial differentiation towards astrocyte-like cells with better neuroprotective activity against 6-OHDA toxicity than naïve DPSCs.
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Affiliation(s)
- Kavina Ganapathy
- Department of Biophysics, National Institute of Mental Health and Neurosciences, P.B. No - 2900, Hosur Road, Bengaluru, Karnataka, 560029, India.,School of Regenerative Medicine, Manipal University, Bengaluru, Karnataka, 560065, India
| | - Indrani Datta
- Department of Biophysics, National Institute of Mental Health and Neurosciences, P.B. No - 2900, Hosur Road, Bengaluru, Karnataka, 560029, India.
| | - Ramesh Bhonde
- School of Regenerative Medicine, Manipal University, Bengaluru, Karnataka, 560065, India.,Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune, Maharashtra, 411018, India
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Datta I, Ganapathy K, Razdan R, Bhonde R. Location and Number of Astrocytes Determine Dopaminergic Neuron Survival and Function Under 6-OHDA Stress Mediated Through Differential BDNF Release. Mol Neurobiol 2017; 55:5505-5525. [PMID: 28965325 DOI: 10.1007/s12035-017-0767-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Accepted: 09/06/2017] [Indexed: 02/08/2023]
Abstract
While astrocytes throughout the CNS share many common traits, they exhibit significant differences in function and number among brain regions. The aim of the present study is to assess the effect of region-specificity and number of astrocytes on the survival of dopaminergic neurons under stress, and to understand the possible mechanism by which these astrocytes extend neuroprotection to dopaminergic neurons. Purified astrocytes obtained from forebrain, midbrain, and hindbrain region were characterized through FACS and immunofluorescence. Co-culture experiments (using trans-wells) were then performed to measure the effect of region-specificities and numbers of astrocytes on primary midbrain culture under 6-OHDA stress. Cell survival augmented with an increase in astrocyte seeding number and total cell survival was comparable among the different region-specific astrocytes for all numbers. However, striking differences were observed in dopaminergic neuronal (TH) cell survival in the presence of midbrain astrocytes in comparison to forebrain and hindbrain astrocytes at all seeding numbers. At 75 μM 6-OHDA insult, while cell survival was comparable in purified astrocytes from the different brain regions, a distinct increase in BDNF secretion (significantly higher than its constitutive release) was noted for midbrain astrocytes compared to forebrain and hindbrain astrocytes. The TH immunopositive population decreased when TrkB inhibitor was added to the co-culture under 6-OHDA toxicity, suggesting that BDNF released by co-cultured astrocytes plays a key role in the survival of dopaminergic neurons. This BDNF release decreased in presence of NO inhibitor and increased in the presence of NO donor (DETA/NO). We conclude that the BDNF released from astrocytes under 6-OHDA toxicity is mediated through NO release through both autocrine and paracrine signaling, and this BDNF release is primarily responsible for the differential effect of region-specific astrocytes on TH neuron survival under these conditions.
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Affiliation(s)
- Indrani Datta
- Department of Biophysics, National Institute of Mental Health and Neurosciences, an Institute of National Importance, P.B. No 2900, Hosur Road, Bengaluru, Karnataka, 560029, India.
| | - Kavina Ganapathy
- Department of Pharmacology, Al-Ameen College of Pharmacy, Bengaluru, Karnataka, India
| | - Rema Razdan
- School of Regenerative Medicine, Manipal University, Bengaluru, Karnataka, India
| | - Ramesh Bhonde
- Department of Pharmacology, Al-Ameen College of Pharmacy, Bengaluru, Karnataka, India
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27
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Khakh BS, Beaumont V, Cachope R, Munoz-Sanjuan I, Goldman SA, Grantyn R. Unravelling and Exploiting Astrocyte Dysfunction in Huntington's Disease. Trends Neurosci 2017; 40:422-437. [PMID: 28578789 PMCID: PMC5706770 DOI: 10.1016/j.tins.2017.05.002] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 04/24/2017] [Accepted: 05/01/2017] [Indexed: 01/02/2023]
Abstract
Astrocytes are abundant within mature neural circuits and are involved in brain disorders. Here, we summarize our current understanding of astrocytes and Huntington's disease (HD), with a focus on correlative and causative dysfunctions of ion homeostasis, calcium signaling, and neurotransmitter clearance, as well as on the use of transplanted astrocytes to produce therapeutic benefit in mouse models of HD. Overall, the data suggest that astrocyte dysfunction is an important contributor to the onset and progression of some HD symptoms in mice. Additional exploration of astrocytes in HD mouse models and humans is needed and may provide new therapeutic opportunities to explore in conjunction with neuronal rescue and repair strategies.
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Affiliation(s)
- Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA; Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095-1751, USA.
| | - Vahri Beaumont
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, CA 90045, USA
| | - Roger Cachope
- CHDI Management/CHDI Foundation, 6080 Center Drive, Los Angeles, CA 90045, USA
| | | | - Steven A Goldman
- Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA; Center for Neuroscience, University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Rosemarie Grantyn
- Exzellenzcluster NeuroCure & Abt. Experimentelle Neurologie, Charité - Universitätsmedizin Berlin, Robert-Koch-Platz 4, D-10115 Berlin, Germany
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28
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Wang Q, Jie W, Liu JH, Yang JM, Gao TM. An astroglial basis of major depressive disorder? An overview. Glia 2017; 65:1227-1250. [DOI: 10.1002/glia.23143] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 02/26/2017] [Accepted: 02/27/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Qian Wang
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, Southern Medical University; Guangzhou 510515 China
| | - Wei Jie
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, Southern Medical University; Guangzhou 510515 China
| | - Ji-Hong Liu
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, Southern Medical University; Guangzhou 510515 China
| | - Jian-Ming Yang
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, Southern Medical University; Guangzhou 510515 China
| | - Tian-Ming Gao
- State Key Laboratory of Organ Failure Research, Key Laboratory of Psychiatric Disorders of Guangdong Province, Collaborative Innovation Center for Brain Science, Department of Neurobiology, Southern Medical University; Guangzhou 510515 China
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29
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Kjaerby C, Rasmussen R, Andersen M, Nedergaard M. Does Global Astrocytic Calcium Signaling Participate in Awake Brain State Transitions and Neuronal Circuit Function? Neurochem Res 2017; 42:1810-1822. [PMID: 28210958 DOI: 10.1007/s11064-017-2195-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 12/31/2022]
Abstract
We continuously need to adapt to changing conditions within our surrounding environment, and our brain needs to quickly shift between resting and working activity states in order to allow appropriate behaviors. These global state shifts are intimately linked to the brain-wide release of the neuromodulators, noradrenaline and acetylcholine. Astrocytes have emerged as a new player participating in the regulation of brain activity, and have recently been implicated in brain state shifts. Astrocytes display global Ca2+ signaling in response to activation of the noradrenergic system, but whether astrocytic Ca2+ signaling is causative or correlative for shifts in brain state and neural activity patterns is not known. Here we review the current available literature on astrocytic Ca2+ signaling in awake animals in order to explore the role of astrocytic signaling in brain state shifts. Furthermore, we look at the development and availability of innovative new methodological tools that are opening up for new ways of visualizing and perturbing astrocyte activity in awake behaving animals. With these new tools at hand, the field of astrocyte research will likely be able to elucidate the causal and mechanistic roles of astrocytes in complex behaviors within a very near future.
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Affiliation(s)
- Celia Kjaerby
- Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Building 24.2, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Rune Rasmussen
- Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Building 24.2, Blegdamsvej 3B, 2200, Copenhagen N, Denmark.,Department of Biomedicine, The Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, 8000, Aarhus C, Denmark
| | - Mie Andersen
- Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Building 24.2, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Maiken Nedergaard
- Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Building 24.2, Blegdamsvej 3B, 2200, Copenhagen N, Denmark. .,Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA.
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30
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Srinivasan R, Lu TY, Chai H, Xu J, Huang BS, Golshani P, Coppola G, Khakh BS. New Transgenic Mouse Lines for Selectively Targeting Astrocytes and Studying Calcium Signals in Astrocyte Processes In Situ and In Vivo. Neuron 2016; 92:1181-1195. [PMID: 27939582 PMCID: PMC5403514 DOI: 10.1016/j.neuron.2016.11.030] [Citation(s) in RCA: 237] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/14/2016] [Accepted: 11/15/2016] [Indexed: 11/23/2022]
Abstract
Astrocytes exist throughout the nervous system and are proposed to affect neural circuits and behavior. However, studying astrocytes has proven difficult because of the lack of tools permitting astrocyte-selective genetic manipulations. Here, we report the generation of Aldh1l1-Cre/ERT2 transgenic mice to selectively target astrocytes in vivo. We characterized Aldh1l1-Cre/ERT2 mice using imaging, immunohistochemistry, AAV-FLEX-GFP microinjections, and crosses to RiboTag, Ai95, and new Cre-dependent membrane-tethered Lck-GCaMP6f knockin mice that we also generated. Two to three weeks after tamoxifen induction, Aldh1l1-Cre/ERT2 selectively targeted essentially all adult (P80) brain astrocytes with no detectable neuronal contamination, resulting in expression of cytosolic and Lck-GCaMP6f, and permitting subcellular astrocyte calcium imaging during startle responses in vivo. Crosses with RiboTag mice allowed sequencing of actively translated mRNAs and determination of the adult cortical astrocyte transcriptome. Thus, we provide well-characterized, easy-to-use resources with which to selectively study astrocytes in situ and in vivo in multiple experimental scenarios.
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Affiliation(s)
- Rahul Srinivasan
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Tsai-Yi Lu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Hua Chai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Ji Xu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Ben S Huang
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Integrative Center for Learning and Memory, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; West Los Angeles VA Medical Center, Los Angeles, CA 90073, USA
| | - Giovanni Coppola
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
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31
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Chen N, Sugihara H, Kim J, Fu Z, Barak B, Sur M, Feng G, Han W. Direct modulation of GFAP-expressing glia in the arcuate nucleus bi-directionally regulates feeding. eLife 2016; 5. [PMID: 27751234 PMCID: PMC5068968 DOI: 10.7554/elife.18716] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 09/17/2016] [Indexed: 12/18/2022] Open
Abstract
Multiple hypothalamic neuronal populations that regulate energy balance have been identified. Although hypothalamic glia exist in abundance and form intimate structural connections with neurons, their roles in energy homeostasis are less known. Here we show that selective Ca2+ activation of glia in the mouse arcuate nucleus (ARC) reversibly induces increased food intake while disruption of Ca2+ signaling pathway in ARC glia reduces food intake. The specific activation of ARC glia enhances the activity of agouti-related protein/neuropeptide Y (AgRP/NPY)-expressing neurons but induces no net response in pro-opiomelanocortin (POMC)-expressing neurons. ARC glial activation non-specifically depolarizes both AgRP/NPY and POMC neurons but a strong inhibitory input to POMC neurons balances the excitation. When AgRP/NPY neurons are inactivated, ARC glial activation fails to evoke any significant changes in food intake. Collectively, these results reveal an important role of ARC glia in the regulation of energy homeostasis through its interaction with distinct neuronal subtype-specific pathways.
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Affiliation(s)
- Naiyan Chen
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore.,Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States
| | - Hiroki Sugihara
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, United States
| | - Jinah Kim
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States
| | - Zhanyan Fu
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States.,Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, United States
| | - Boaz Barak
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States
| | - Mriganka Sur
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, United States
| | - Guoping Feng
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, United States.,Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, United States
| | - Weiping Han
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, A*STAR, Singapore, Singapore
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32
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Nuriya M, Hirase H. Involvement of astrocytes in neurovascular communication. PROGRESS IN BRAIN RESEARCH 2016; 225:41-62. [PMID: 27130410 DOI: 10.1016/bs.pbr.2016.02.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The vascular interface of the brain is distinct from that of the peripheral tissue in that astrocytes, the most numerous glial cell type in the gray matter, cover the vasculature with their endfeet. This morphological feature of the gliovascular junction has prompted neuroscientists to suggest possible functional roles of astrocytes including astrocytic modulation of the vasculature. Additionally, astrocytes develop an intricate morphology that intimately apposes neuronal synapses, making them an ideal cellular mediator of neurovascular coupling. In this article, we first introduce the classical anatomical and physiological findings that led to the proposal of various gliovascular interaction models. Next, we touch on the technological advances in the past few decades that enabled investigations and evaluations of neuro-glio-vascular interactions in situ. We then review recent experimental findings on the roles of astrocytes in neurovascular coupling from the viewpoints of intra- and intercellular signalings in astrocytes.
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Affiliation(s)
- M Nuriya
- Keio University, Shinjuku, Tokyo, Japan
| | - H Hirase
- RIKEN Brain Science Institute, Wako, Saitama, Japan.
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33
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Wilhelm CJ, Guizzetti M. Fetal Alcohol Spectrum Disorders: An Overview from the Glia Perspective. Front Integr Neurosci 2016; 9:65. [PMID: 26793073 PMCID: PMC4707276 DOI: 10.3389/fnint.2015.00065] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 12/10/2015] [Indexed: 01/30/2023] Open
Abstract
Alcohol consumption during pregnancy can produce a variety of central nervous system (CNS) abnormalities in the offspring resulting in a broad spectrum of cognitive and behavioral impairments that constitute the most severe and long-lasting effects observed in fetal alcohol spectrum disorders (FASD). Alcohol-induced abnormalities in glial cells have been suspected of contributing to the adverse effects of alcohol on the developing brain for several years, although much research still needs to be done to causally link the effects of alcohol on specific brain structures and behavior to alterations in glial cell development and function. Damage to radial glia due to prenatal alcohol exposure may underlie observations of abnormal neuronal and glial migration in humans with Fetal Alcohol Syndrome (FAS), as well as primate and rodent models of FAS. A reduction in cell number and altered development has been reported for several glial cell types in animal models of FAS. In utero alcohol exposure can cause microencephaly when alcohol exposure occurs during the brain growth spurt a period characterized by rapid astrocyte proliferation and maturation; since astrocytes are the most abundant cells in the brain, microenchephaly may be caused by reduced astrocyte proliferation or survival, as observed in in vitro and in vivo studies. Delayed oligodendrocyte development and increased oligodendrocyte precursor apoptosis has also been reported in experimental models of FASD, which may be linked to altered myelination/white matter integrity found in FASD children. Children with FAS exhibit hypoplasia of the corpus callosum and anterior commissure, two areas requiring guidance from glial cells and proper maturation of oligodendrocytes. Finally, developmental alcohol exposure disrupts microglial function and induces microglial apoptosis; given the role of microglia in synaptic pruning during brain development, the effects of alcohol on microglia may be involved in the abnormal brain plasticity reported in FASD. The consequences of prenatal alcohol exposure on glial cells, including radial glia and other transient glial structures present in the developing brain, astrocytes, oligodendrocytes and their precursors, and microglia contributes to abnormal neuronal development, reduced neuron survival and disrupted brain architecture and connectivity. This review highlights the CNS structural abnormalities caused by in utero alcohol exposure and outlines which abnormalities are likely mediated by alcohol effects on glial cell development and function.
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Affiliation(s)
- Clare J Wilhelm
- Research Service, VA Portland Health Care SystemPortland, OR, USA; Department of Psychiatry, Oregon Health and Science UniversityPortland, OR, USA
| | - Marina Guizzetti
- Research Service, VA Portland Health Care SystemPortland, OR, USA; Department of Behavioral Neuroscience, Oregon Health and Science UniversityPortland, OR, USA
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34
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Hoogland TM, Parpura V. Editorial: The role of glia in plasticity and behavior. Front Cell Neurosci 2015; 9:356. [PMID: 26441527 PMCID: PMC4563082 DOI: 10.3389/fncel.2015.00356] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 08/24/2015] [Indexed: 11/20/2022] Open
Affiliation(s)
- Tycho M Hoogland
- Netherlands Institute for Neuroscience Amsterdam, Netherlands ; Department of Neuroscience, Erasmus MC Rotterdam, Netherlands
| | - Vladimir Parpura
- Atomic Force Microscopy and Nanotechnology Laboratories, Department of Neurobiology, Center for Glial Biology in Medicine, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham Birmingham, AL, USA
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35
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Do stars govern our actions? Astrocyte involvement in rodent behavior. Trends Neurosci 2015; 38:535-49. [DOI: 10.1016/j.tins.2015.07.006] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 07/24/2015] [Accepted: 07/28/2015] [Indexed: 12/20/2022]
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