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Che LQ, Qu ZZ, Mao ZF, Qiao Q, Zhou KP, Jia LJ, Wang WP. Low-frequency rTMS Plays a Neuroprotective role in Pilocarpine-induced Status Epilepticus Rat Models Through the AMPAR GluA1-STIM-Ca 2+ Pathway. Mol Neurobiol 2024:10.1007/s12035-024-04521-w. [PMID: 39384697 DOI: 10.1007/s12035-024-04521-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 09/23/2024] [Indexed: 10/11/2024]
Abstract
Low-frequency repetitive transcranial magnetic stimulation (rTMS) refers to the stimulation of the brain using repetitive magnetic field pulses at a low frequency (≤ 1 Hz) to reduce seizures. Currently, the mechanism is not well understood. Male Sprague-Dawley rats underwent pilocarpine-induced status epilepticus (SE) and were then stimulated with low-frequency rTMS. An epilepsy cell model was then established by incubating rat hippocampal neurons with Mg2+-free extracellular fluids. The effects of the low-frequency rTMS on epileptogenesis and hippocampal neuron injury were evaluated using a video electroencephalogram (vEEG) and Nissl staining, and the expression of AMPAR GluA1 and STIM in the hippocampus and hippocampal neurons was assessed using western blot and immunofluorescence. Additionally, the intracellular Ca2+ concentration and reactive oxygen species (ROS) were measured using flow cytometry. Low-frequency rTMS attenuated spontaneous recurrent seizures in rats with epilepsy, with the SE group exhibiting a higher incidence (100%) and frequency (3.00 ± 0.18 times/day) than the SE + 0.3 (50% incidence, 0.06 ± 0.03 times/day), SE + 0.5 (0.20 ± 0.02 times/day) and SE + 1 Hz (1.02 ± 0.05 times/day) groups. Additionally, rTMS reduced the damage and apoptosis of hippocampal pyramidal neurons, increasing their numbers in the CA1 and CA3 regions. Furthermore, AMPAR GluA1 and STIM expression were upregulated in the hippocampus when using rTMS, reversing the downregulation caused by seizures. Immunofluorescence verified the increased fluorescence intensity of AMPAR GluA1 and STIM. Moreover, rTMS inhibited Ca2+ overload and ROS in epileptic neuron models. Low-frequency rTMS may exert neuroprotective effects through the AMPAR GluA1-STIM-Ca2+ pathway.
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Affiliation(s)
- Li-Qin Che
- Department of Neurology, The Second Hospital of Hebei Medical University, No.215 of West Heping Road, Xinhua District, Shijiazhuang, 050000, Hebei Province, China
| | - Zhen-Zhen Qu
- Department of Neurology, The Second Hospital of Hebei Medical University, No.215 of West Heping Road, Xinhua District, Shijiazhuang, 050000, Hebei Province, China
| | - Zhuo-Feng Mao
- Department of Neurology, The Second Hospital of Hebei Medical University, No.215 of West Heping Road, Xinhua District, Shijiazhuang, 050000, Hebei Province, China
| | - Qi Qiao
- Department of Neurology, The Second Hospital of Hebei Medical University, No.215 of West Heping Road, Xinhua District, Shijiazhuang, 050000, Hebei Province, China
| | - Kai-Ping Zhou
- Department of Neurology, The Second Hospital of Hebei Medical University, No.215 of West Heping Road, Xinhua District, Shijiazhuang, 050000, Hebei Province, China
| | - Li-Jing Jia
- Department of Neurology, The Second Hospital of Hebei Medical University, No.215 of West Heping Road, Xinhua District, Shijiazhuang, 050000, Hebei Province, China.
| | - Wei-Ping Wang
- Department of Neurology, The Second Hospital of Hebei Medical University, No.215 of West Heping Road, Xinhua District, Shijiazhuang, 050000, Hebei Province, China.
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2
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Tan W, Ikoma Y, Takahashi Y, Konno A, Hirai H, Hirase H, Matsui K. Anxiety control by astrocytes in the lateral habenula. Neurosci Res 2024; 205:1-15. [PMID: 38311032 DOI: 10.1016/j.neures.2024.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/17/2024] [Accepted: 01/21/2024] [Indexed: 02/06/2024]
Abstract
The potential role of astrocytes in lateral habenula (LHb) in modulating anxiety was explored in this study. The habenula are a pair of small nuclei located above the thalamus, known for their involvement in punishment avoidance and anxiety. Herein, we observed an increase in theta-band oscillations of local field potentials (LFPs) in the LHb when mice were exposed to anxiety-inducing environments. Electrical stimulation of LHb at theta-band frequency promoted anxiety-like behavior. Calcium (Ca2+) levels and pH in the cytosol of astrocytes and local brain blood volume changes were studied in mice expressing either a Ca2+ or a pH sensor protein specifically in astrocytes and mScarlet fluorescent protein in the blood plasma using fiber photometry. An acidification response to anxiety was observed. Photoactivation of archaerhopsin-T (ArchT), an optogenetic tool that acts as an outward proton pump, results in intracellular alkalinization. Photostimulation of LHb in astrocyte-specific ArchT-expressing mice resulted in dissipation of theta-band LFP oscillation in an anxiogenic environment and suppression of anxiety-like behavior. These findings provide evidence that LHb astrocytes modulate anxiety and may offer a new target for treatment of anxiety disorders.
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Affiliation(s)
- Wanqin Tan
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan
| | - Yoko Ikoma
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan
| | - Yusuke Takahashi
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan; Systems Bioinformatics, Graduate School of Information Sciences, Tohoku University, Sendai 980-8579 Japan
| | - Ayumu Konno
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi 371-8511, Gunma, Japan; Viral Vector Core, Gunma University Initiative for Advanced Research, Maebashi 371-8511, Gunma, Japan
| | - Hirokazu Hirai
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi 371-8511, Gunma, Japan; Viral Vector Core, Gunma University Initiative for Advanced Research, Maebashi 371-8511, Gunma, Japan
| | - Hajime Hirase
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark; Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Ko Matsui
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan.
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3
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Baldwin KT, Murai KK, Khakh BS. Astrocyte morphology. Trends Cell Biol 2024; 34:547-565. [PMID: 38180380 DOI: 10.1016/j.tcb.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/18/2023] [Accepted: 09/29/2023] [Indexed: 01/06/2024]
Abstract
Astrocytes are predominant glial cells that tile the central nervous system (CNS). A cardinal feature of astrocytes is their complex and visually enchanting morphology, referred to as bushy, spongy, and star-like. A central precept of this review is that such complex morphological shapes evolved to allow astrocytes to contact and signal with diverse cells at a range of distances in order to sample, regulate, and contribute to the extracellular milieu, and thus participate widely in cell-cell signaling during physiology and disease. The recent use of improved imaging methods and cell-specific molecular evaluations has revealed new information on the structural organization and molecular underpinnings of astrocyte morphology, the mechanisms of astrocyte morphogenesis, and the contributions to disease states of reduced morphology. These insights have reignited interest in astrocyte morphological complexity as a cornerstone of fundamental glial biology and as a critical substrate for multicellular spatial and physiological interactions in the CNS.
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Affiliation(s)
- Katherine T Baldwin
- Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Keith K Murai
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Avenue, Montreal, QC H3G 1A4, Canada.
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90034, USA; Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90034, USA.
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4
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Chen X, Bell NA, Coffman BL, Rabino AA, Garcia-Mata R, Kammermeier PJ, Yule DI, Axelrod D, Smrcka AV, Giovannucci DR, Anantharam A. A PACAP-activated network for secretion requires coordination of Ca 2+ influx and Ca 2+ mobilization. Mol Biol Cell 2024; 35:ar92. [PMID: 38758660 PMCID: PMC11244167 DOI: 10.1091/mbc.e24-02-0083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/26/2024] [Accepted: 05/07/2024] [Indexed: 05/19/2024] Open
Abstract
Chromaffin cells of the adrenal medulla transduce sympathetic nerve activity into stress hormone secretion. The two neurotransmitters principally responsible for coupling cell stimulation to secretion are acetylcholine and pituitary adenylate activating polypeptide (PACAP). In contrast to acetylcholine, PACAP evokes a persistent secretory response from chromaffin cells. However, the mechanisms by which PACAP acts are poorly understood. Here, it is shown that PACAP induces sustained increases in cytosolic Ca2+ which are disrupted when Ca2+ influx through L-type channels is blocked or internal Ca2+ stores are depleted. PACAP liberates stored Ca2+ via inositol trisphosphate receptors (IP3Rs) on the endoplasmic reticulum (ER), thereby functionally coupling Ca2+ mobilization to Ca2+ influx and supporting Ca2+-induced Ca2+-release. These Ca2+ influx and mobilization pathways are unified by an absolute dependence on phospholipase C epsilon (PLCε) activity. Thus, the persistent secretory response that is a defining feature of PACAP activity, in situ, is regulated by a signaling network that promotes sustained elevations in intracellular Ca2+ through multiple pathways.
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Affiliation(s)
- Xiaohuan Chen
- Department of Neurosciences, University of Toledo, Toledo, OH 43614
| | - Nicole A. Bell
- Department of Neurosciences, University of Toledo, Toledo, OH 43614
| | | | | | | | - Paul J. Kammermeier
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14627
| | - David I. Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14627
| | | | - Alan V. Smrcka
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109
| | | | - Arun Anantharam
- Department of Neurosciences, University of Toledo, Toledo, OH 43614
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5
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Zipursky S, Lee J, Sergeeva A, Ahlsen G, Mannepalli S, Bahna F, Goodman K, Khakh B, Weiner J, Shapiro L, Honig B. Astrocyte morphogenesis requires self-recognition. RESEARCH SQUARE 2024:rs.3.rs-3932947. [PMID: 38463964 PMCID: PMC10925414 DOI: 10.21203/rs.3.rs-3932947/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Self-recognition is a fundamental cellular process across evolution and forms the basis of neuronal self-avoidance1-4. Clustered protocadherins (Pcdh), comprising a large family of isoform-specific homophilic recognition molecules, play a pivotal role in neuronal self-avoidance required for mammalian brain development5-7. The probabilistic expression of different Pcdh isoforms confers unique identities upon neurons and forms the basis for neuronal processes to discriminate between self and non-self5,6,8. Whether this self-recognition mechanism exists in astrocytes, the other predominant cell type of the brain, remains unknown. Here, we report that a specific isoform in the Pcdhγ cluster, γC3, is highly enriched in human and murine astrocytes. Through genetic manipulation, we demonstrate that γC3 acts autonomously to regulate astrocyte morphogenesis in the mouse visual cortex. To determine if γC3 proteins act by promoting recognition between processes of the same astrocyte, we generated pairs of γC3 chimeric proteins capable of heterophilic binding to each other, but incapable of homophilic binding. Co-expressing complementary heterophilic binding isoform pairs in the same γC3 null astrocyte restored normal morphology. By contrast, chimeric γC3 proteins individually expressed in single γC3 null mutant astrocytes did not. These data establish that self-recognition is essential for astrocyte development in the mammalian brain and that, by contrast to neuronal self-recognition, a single Pcdh isoform is both necessary and sufficient for this process.
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Affiliation(s)
| | - John Lee
- University of California Los Angeles
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6
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Peng H, Ding L, Fang Y. Recent Advances in Construction Strategies for Fluorescence Sensing Films. J Phys Chem Lett 2024; 15:849-862. [PMID: 38236759 DOI: 10.1021/acs.jpclett.3c03130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
A year ago, film-based fluorescent sensors (FFSs) were recognized in the "IUPAC Top Ten Emerging Technologies in Chemistry 2022" due to their extensive application in detecting hidden explosives, illicit drugs, and volatile organic compounds. These sensors offer high sensitivity, specificity, immunity to light scattering, and noninvasiveness. The core of FFSs is the construction of high-performance fluorescent sensing films, which are dependent on the processes of "energy transfer" and "mass transfer" in the active layer and involve complex interactions between sensing molecules and analytes. This Perspective focuses on the latest strategies in constructing these films, emphasizing the design of sensing molecules with various innovative features and structures that enhance the mass transfer efficiency. Additionally, it discusses the ongoing challenges and potential advancements in the field of FFSs.
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Affiliation(s)
- Haonan Peng
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China
| | - Liping Ding
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China
| | - Yu Fang
- Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China
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7
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Chen X, Bell NA, Coffman BL, Rabino AA, Garcia-Mata R, Kammermeier PJ, Yule DI, Axelrod D, Smrcka AV, Giovannucci DR, Anantharam A. A PACAP-activated network for secretion requires coordination of Ca 2+ influx and Ca 2+ mobilization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.03.574069. [PMID: 38260572 PMCID: PMC10802325 DOI: 10.1101/2024.01.03.574069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Chromaffin cells of the adrenal medulla transduce sympathetic nerve activity into stress hormone secretion. The two neurotransmitters principally responsible for coupling cell stimulation to secretion are acetylcholine and pituitary adenylate activating polypeptide (PACAP). In contrast to acetylcholine, PACAP evokes a persistent secretory response from chromaffin cells. However, the mechanisms by which PACAP acts are poorly understood. Here, it is shown that PACAP induces sustained increases in cytosolic Ca 2+ which are disrupted when Ca 2+ influx through L-type channels is blocked or internal Ca 2+ stores are depleted. PACAP liberates stored Ca 2+ via inositol trisphosphate receptors (IP3Rs) on the endoplasmic reticulum (ER), thereby functionally coupling Ca 2+ mobilization to Ca 2+ influx and supporting Ca 2+ -induced Ca 2+ -release. These Ca 2+ influx and mobilization pathways are unified by an absolute dependence on phospholipase C epsilon (PLCε) activity. Thus, the persistent secretory response that is a defining feature of PACAP activity, in situ , is regulated by a signaling network that promotes sustained elevations in intracellular Ca 2+ through multiple pathways.
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8
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Hjukse JB, Puebla MFDL, Vindedal GF, Sprengel R, Jensen V, Nagelhus EA, Tang W. Increased membrane Ca 2+ permeability drives astrocytic Ca 2+ dynamics during neuronal stimulation at excitatory synapses. Glia 2023; 71:2770-2781. [PMID: 37564028 DOI: 10.1002/glia.24450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 07/13/2023] [Accepted: 07/21/2023] [Indexed: 08/12/2023]
Abstract
Astrocytes are intricately involved in the activity of neural circuits; however, their basic physiology of interacting with nearby neurons is not well established. Using two-photon imaging of neurons and astrocytes during higher frequency stimulation of hippocampal CA3-CA1 Schaffer collateral (Scc) excitatory synapses, we could show that increasing levels of released glutamate accelerated local astrocytic Ca2+ elevation. However, blockage of glutamate transporters did not abolish this astrocytic Ca2+ response, suggesting that astrocytic Ca2+ elevation is indirectly associated with an uptake of extracellular glutamate. However, during the astrocytic glutamate uptake, the Na+ /Ca2+ exchanger (NCX) reverse mode was activated, and mediated extracellular Ca2+ entry, thereby triggering the internal release of Ca2+ . In addition, extracellular Ca2+ entry via membrane P2X receptors further facilitated astrocytic Ca2+ elevation via ATP binding. These findings suggest a novel mechanism of activity induced Ca2+ permeability increases of astrocytic membranes, which drives astrocytic responses during neuronal stimulation of CA3-CA1 Scc excitatory synapses.
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Affiliation(s)
- Jarand B Hjukse
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Mario F D L Puebla
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Department of Neurology, Neuroclinic, St. Olavs Hospital, Trondheim, Norway
| | - Gry Fluge Vindedal
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Rolf Sprengel
- Department of Neurology, Oslo University Hospital, Oslo, Norway
| | - Vidar Jensen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Erlend A Nagelhus
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
- Research Group of Molecular Neurobiology, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Wannan Tang
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Department of Neurology, Neuroclinic, St. Olavs Hospital, Trondheim, Norway
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9
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Chen Y, Pang S, Li J, Lu Y, Gao C, Xiao Y, Chen M, Wang M, Ren X. Genetically encoded protein sensors for metal ion detection in biological systems: a review and bibliometric analysis. Analyst 2023; 148:5564-5581. [PMID: 37872814 DOI: 10.1039/d3an01412f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Metal ions are indispensable elements in living organisms and are associated with regulating various biological processes. An imbalance in metal ion content can lead to disorders in normal physiological functions of the human body and cause various diseases. Genetically encoded fluorescent protein sensors have the advantages of low biotoxicity, high specificity, and a long imaging time in vivo and have become a powerful tool to visualize or quantify the concentration level of biomolecules in vivo and in vitro, temporal and spatial distribution, and life activity process. This review analyzes the development status and current research hotspots in the field of genetically encoded fluorescent protein sensors by bibliometric analysis. Based on the results of bibliometric analysis, the research progress of genetically encoded fluorescent protein sensors for metal ion detection is reviewed, and the construction strategies, physicochemical properties, and applications of such sensors in biological imaging are summarized.
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Affiliation(s)
- Yuxueyuan Chen
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300381, China
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - ShuChao Pang
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300381, China
| | - Jingya Li
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Yun Lu
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Chenxia Gao
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Yanyu Xiao
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Meiling Chen
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
- Tianjin Key Laboratory of Therapeutic Substance of Traditional Chinese Medicine, Tianjin 301617, China.
| | - Meng Wang
- State Key Laboratory of Component-based Chinese Medicine, Tianjin 301617, China
| | - Xiaoliang Ren
- College of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
- Tianjin Key Laboratory of Therapeutic Substance of Traditional Chinese Medicine, Tianjin 301617, China.
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10
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Chen X, Coffman BL, Brindley RL, Galpin JD, Ahern CA, Currie KPM, Smrcka AV, Axelrod D, Anantharam A. Phospholipase C-ε defines a PACAP-stimulated pathway for secretion in the chromaffin cell. J Neuroendocrinol 2023; 35:e13255. [PMID: 36970756 PMCID: PMC10790106 DOI: 10.1111/jne.13255] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/15/2023] [Accepted: 03/08/2023] [Indexed: 03/13/2023]
Abstract
Adrenomedullary chromaffin cells respond to splanchnic (sympathetic) nerve stimulation by releasing stress hormones into the circulation. The signal for hormone secretion is encoded in the neurotransmitters - especially acetylcholine (ACh) and pituitary adenylate cyclase activating polypeptide (PACAP) - that are released into the splanchnic-chromaffin cell synapse. However, functional differences in the effects of ACh and PACAP on the chromaffin cell secretory response are not well defined. Here, selective agonists of PACAP receptors or nicotinic and muscarinic acetylcholine receptors were applied to chromaffin cells. The major differences in the effects of these agents were not on exocytosis, per se, but rather on the steps upstream of exocytosis. In almost every respect, the properties of individual fusion events triggered by PACAP and cholinergic agonists were similar. On the other hand, the properties of the Ca2+ transients evoked by PACAP differed in several ways from those evoked by muscarinic and nicotinic receptor stimulation. A defining feature of the PACAP-stimulated secretory pathway was its dependence on signaling through exchange protein directly activated by cAMP (Epac) and PLCε. However, the absence of PLCε did not disrupt Ca2+ transients evoked by cholinergic agonists. Accordingly, inhibition of Epac activity did not disrupt secretion triggered by acetylcholine or specific agonists of muscarinic and nicotinic receptors. Thus, PACAP and acetylcholine stimulate chromaffin cell secretion via separate and independent pathways. This feature of stimulus-secretion coupling may be important for sustaining hormone release from the adrenal medulla under conditions associated with the sympathetic stress response.
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Affiliation(s)
- Xiaohuan Chen
- Department of Neurosciences, University of Toledo, Toledo, Ohio, 43606, USA
| | - Breanna L. Coffman
- Department of Neurosciences, University of Toledo, Toledo, Ohio, 43606, USA
| | - Rebecca L. Brindley
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey, 08103, USA
| | - Jason D. Galpin
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, Iowa, 52246, USA
| | - Christopher A. Ahern
- Department of Molecular Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, Iowa, 52246, USA
| | - Kevin P. M. Currie
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey, 08103, USA
| | - Alan V. Smrcka
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Daniel Axelrod
- Department of Physics and LSA Biophysics, University of Michigan, Ann Arbor, Michigan, 48109, USA
| | - Arun Anantharam
- Department of Neurosciences, University of Toledo, Toledo, Ohio, 43606, USA
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11
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Siemsen BM, Denton AR, Parrila-Carrero J, Hooker KN, Carpenter EA, Prescot ME, Brock AG, Westphal AM, Leath MN, McFaddin JA, Jhou TC, McGinty JF, Scofield MD. Heroin Self-Administration and Extinction Increase Prelimbic Cortical Astrocyte-Synapse Proximity and Alter Dendritic Spine Morphometrics That Are Reversed by N-Acetylcysteine. Cells 2023; 12:1812. [PMID: 37508477 PMCID: PMC10378353 DOI: 10.3390/cells12141812] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 05/09/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023] Open
Abstract
Clinical and preclinical studies indicate that adaptations in corticostriatal neurotransmission significantly contribute to heroin relapse vulnerability. In animal models, heroin self-administration and extinction produce cellular adaptations in both neurons and astrocytes within the nucleus accumbens (NA) core that are required for cue-induced heroin seeking. Specifically, decreased glutamate clearance and reduced association of perisynaptic astrocytic processes with NAcore synapses allow glutamate release from prelimbic (PrL) cortical terminals to engage synaptic and structural plasticity in NAcore medium spiny neurons. Normalizing astrocyte glutamate homeostasis with drugs like the antioxidant N-acetylcysteine (NAC) prevents cue-induced heroin seeking. Surprisingly, little is known about heroin-induced alterations in astrocytes or pyramidal neurons projecting to the NAcore in the PrL cortex (PrL-NAcore). Here, we observe functional adaptations in the PrL cortical astrocyte following heroin self-administration (SA) and extinction as measured by the electrophysiologically evoked plasmalemmal glutamate transporter 1 (GLT-1)-dependent current. We likewise observed the increased complexity of the glial fibrillary acidic protein (GFAP) cytoskeletal arbor and increased association of the astrocytic plasma membrane with synaptic markers following heroin SA and extinction training in the PrL cortex. Repeated treatment with NAC during extinction reversed both the enhanced astrocytic complexity and synaptic association. In PrL-NAcore neurons, heroin SA and extinction decreased the apical tuft dendritic spine density and enlarged dendritic spine head diameter in male Sprague-Dawley rats. Repeated NAC treatment during extinction prevented decreases in spine density but not dendritic spine head expansion. Moreover, heroin SA and extinction increased the co-registry of the GluA1 subunit of AMPA receptors in both the dendrite shaft and spine heads of PrL-NAcore neurons. Interestingly, the accumulation of GluA1 immunoreactivity in spine heads was further potentiated by NAC treatment during extinction. Finally, we show that the NAC treatment and elimination of thrombospondin 2 (TSP-2) block cue-induced heroin relapse. Taken together, our data reveal circuit-level adaptations in cortical dendritic spine morphology potentially linked to heroin-induced alterations in astrocyte complexity and association at the synapses. Additionally, these data demonstrate that NAC reverses PrL cortical heroin SA-and-extinction-induced adaptations in both astrocytes and corticostriatal neurons.
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Affiliation(s)
- Benjamin M. Siemsen
- Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Adam R. Denton
- Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | | | - Kaylee N. Hooker
- Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Eilish A. Carpenter
- Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Meagan E. Prescot
- Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Ashley G. Brock
- Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Annaka M. Westphal
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Mary-Nan Leath
- Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - John A. McFaddin
- Department of Anesthesia and Perioperative Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Thomas C. Jhou
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Jacqueline F. McGinty
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Michael D. Scofield
- Department of Anesthesia 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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12
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Fedotova A, Brazhe A, Doronin M, Toptunov D, Pryazhnikov E, Khiroug L, Verkhratsky A, Semyanov A. Dissociation Between Neuronal and Astrocytic Calcium Activity in Response to Locomotion in Mice. FUNCTION 2023; 4:zqad019. [PMID: 37342415 PMCID: PMC10278990 DOI: 10.1093/function/zqad019] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 06/22/2023] Open
Abstract
Locomotion triggers a coordinated response of both neurons and astrocytes in the brain. Here we performed calcium (Ca2+) imaging of these two cell types in the somatosensory cortex in head-fixed mice moving on the airlifted platform. Ca2+ activity in astrocytes significantly increased during locomotion from a low quiescence level. Ca2+ signals first appeared in the distal processes and then propagated to astrocytic somata, where it became significantly larger and exhibited oscillatory behaviour. Thus, astrocytic soma operates as both integrator and amplifier of Ca2+ signal. In neurons, Ca2+ activity was pronounced in quiescent periods and further increased during locomotion. Neuronal Ca2+ concentration ([Ca2+]i) rose almost immediately following the onset of locomotion, whereas astrocytic Ca2+ signals lagged by several seconds. Such a long lag suggests that astrocytic [Ca2+]i elevations are unlikely to be triggered by the activity of synapses among local neurons. Ca2+ responses to pairs of consecutive episodes of locomotion did not significantly differ in neurons, while were significantly diminished in response to the second locomotion in astrocytes. Such astrocytic refractoriness may arise from distinct mechanisms underlying Ca2+ signal generation. In neurons, the bulk of Ca2+ enters through the Ca2+ channels in the plasma membrane allowing for steady-level Ca2+ elevations in repetitive runs. Astrocytic Ca2+ responses originate from the intracellular stores, the depletion of which affects subsequent Ca2+ signals. Functionally, neuronal Ca2+ response reflects sensory input processed by neurons. Astrocytic Ca2+ dynamics is likely to provide metabolic and homeostatic support within the brain active milieu.
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Affiliation(s)
- Anna Fedotova
- Faculty of Biology, Moscow State University, Moscow 119991, Russia
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow 117997, Russia
| | - Alexey Brazhe
- Faculty of Biology, Moscow State University, Moscow 119991, Russia
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow 117997, Russia
| | - Maxim Doronin
- Department of Molecular Neurobiology, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow 117997, Russia
- College of Medicine, Jiaxing University, Jiaxing, Zhejiang Province, 314001, China
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13
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Astrocyte heterogeneity and interactions with local neural circuits. Essays Biochem 2023; 67:93-106. [PMID: 36748397 PMCID: PMC10011406 DOI: 10.1042/ebc20220136] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/09/2023] [Accepted: 01/09/2023] [Indexed: 02/08/2023]
Abstract
Astrocytes are ubiquitous within the central nervous system (CNS). These cells possess many individual processes which extend out into the neuropil, where they interact with a variety of other cell types, including neurons at synapses. Astrocytes are now known to be active players in all aspects of the synaptic life cycle, including synapse formation and elimination, synapse maturation, maintenance of synaptic homeostasis and modulation of synaptic transmission. Traditionally, astrocytes have been studied as a homogeneous group of cells. However, recent studies have uncovered a surprising degree of heterogeneity in their development and function, suggesting that astrocytes may be matched to neurons to support local circuits. Hence, a better understanding of astrocyte heterogeneity and its implications are needed to understand brain function.
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14
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Baudon A, Clauss Creusot E, Charlet A. [Emergent role of astrocytes in oxytocin-mediated modulatory control of neuronal circuits and brain functions]. Biol Aujourdhui 2023; 216:155-165. [PMID: 36744981 DOI: 10.1051/jbio/2022022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Indexed: 02/07/2023]
Abstract
The neuropeptide oxytocin has been in the focus of scientists for decades due to its profound and pleiotropic effects on physiology, activity of neuronal circuits and behaviors. Until recently, it was believed that oxytocinergic action exclusively occurs through direct activation of neuronal oxytocin receptors. However, several studies demonstrated the existence and functional relevance of astroglial oxytocin receptors in various brain regions in the mouse and rat brain. Astrocytic signaling and activity are critical for many important physiological processes including metabolism, neurotransmitter clearance from the synaptic cleft and integrated brain functions. While it can be speculated that oxytocinergic action on astrocytes predominantly facilitates neuromodulation via the release of gliotransmitters, the precise role of astrocytic oxytocin receptors remains elusive. In this review, we discuss the latest studies on the interaction between the oxytocinergic system and astrocytes, and give details of underlying intracellular cascades.
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Affiliation(s)
- Angel Baudon
- Centre National de la Recherche Scientifique et Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, 8 allée du Général Rouvillois, 67000 Strasbourg, France
| | - Etienne Clauss Creusot
- Centre National de la Recherche Scientifique et Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, 8 allée du Général Rouvillois, 67000 Strasbourg, France
| | - Alexandre Charlet
- Centre National de la Recherche Scientifique et Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, 8 allée du Général Rouvillois, 67000 Strasbourg, France
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15
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Morales A, Mohan R, Chen X, Coffman BL, Bendahmane M, Watch L, West JL, Bakshi S, Traynor JR, Giovannucci DR, Kammermeier PJ, Axelrod D, Currie KP, Smrcka AV, Anantharam A. PACAP and acetylcholine cause distinct Ca2+ signals and secretory responses in chromaffin cells. J Gen Physiol 2023; 155:e202213180. [PMID: 36538657 PMCID: PMC9770323 DOI: 10.1085/jgp.202213180] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 09/22/2022] [Accepted: 11/18/2022] [Indexed: 12/24/2022] Open
Abstract
The adrenomedullary chromaffin cell transduces chemical messages into outputs that regulate end organ function throughout the periphery. At least two important neurotransmitters are released by innervating preganglionic neurons to stimulate exocytosis in the chromaffin cell-acetylcholine (ACh) and pituitary adenylate cyclase activating polypeptide (PACAP). Although PACAP is widely acknowledged as an important secretagogue in this system, the pathway coupling PACAP stimulation to chromaffin cell secretion is poorly understood. The goal of this study is to address this knowledge gap. Here, it is shown that PACAP activates a Gαs-coupled pathway that must signal through phospholipase C ε (PLCε) to drive Ca2+ entry and exocytosis. PACAP stimulation causes a complex pattern of Ca2+ signals in chromaffin cells, leading to a sustained secretory response that is kinetically distinct from the form stimulated by ACh. Exocytosis caused by PACAP is associated with slower release of peptide cargo than exocytosis stimulated by ACh. Importantly, only the secretory response to PACAP, not ACh, is eliminated in cells lacking PLCε expression. The data show that ACh and PACAP, acting through distinct signaling pathways, enable nuanced and variable secretory outputs from chromaffin cells.
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Affiliation(s)
- Alina Morales
- Department of Neurosciences, University of Toledo, Toledo, OH, USA
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Ramkumar Mohan
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Xiaohuan Chen
- Department of Neurosciences, University of Toledo, Toledo, OH, USA
| | | | | | - Lester Watch
- Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, NC, USA
| | - Joshua L. West
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Shreeya Bakshi
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - John R. Traynor
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | | | - Paul J. Kammermeier
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
| | - Daniel Axelrod
- Department of Physics and LSA Biophysics, University of Michigan, Ann Arbor, MI, USA
| | - Kevin P.M. Currie
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, NJ, USA
| | - Alan V. Smrcka
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Arun Anantharam
- Department of Neurosciences, University of Toledo, Toledo, OH, USA
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16
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Freitag K, Eede P, Ivanov A, Sterczyk N, Schneeberger S, Borodina T, Sauer S, Beule D, Heppner FL. Diverse but unique astrocytic phenotypes during embryonic stem cell differentiation, culturing and development. Commun Biol 2023; 6:40. [PMID: 36639529 PMCID: PMC9839673 DOI: 10.1038/s42003-023-04410-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 01/03/2023] [Indexed: 01/14/2023] Open
Abstract
Astrocytes are resident glial cells of the central nervous system (CNS) that play complex and heterogeneous roles in brain development, homeostasis and disease. Since their vast involvement in health and disease is becoming increasingly recognized, suitable and reliable tools for studying these cells in vivo and in vitro are of utmost importance. One of the key challenges hereby is to adequately mimic their context-dependent in vivo phenotypes and functions in vitro. To better understand the spectrum of astrocytic variations in defined settings we performed a side-by-side-comparison of murine embryonic stem cell (ESC)-derived astrocytes as well as primary neonatal and adult astrocytes, revealing major differences on a functional and transcriptomic level, specifically on proliferation, migration, calcium signaling and cilium activity. Our results highlight the need to carefully consider the choice of astrocyte origin and phenotype with respect to age, isolation and culture protocols based on the respective biological question.
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Affiliation(s)
- Kiara Freitag
- grid.6363.00000 0001 2218 4662Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Neuropathology, Charitéplatz 1, 10117 Berlin, Germany ,grid.424247.30000 0004 0438 0426German Center for Neurodegenerative Diseases (DZNE) within the Helmholtz Association, Berlin, Germany
| | - Pascale Eede
- grid.6363.00000 0001 2218 4662Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Neuropathology, Charitéplatz 1, 10117 Berlin, Germany ,Present Address: Apollo Health Ventures, Schlüterstr. 36, 10629 Berlin, Germany
| | - Andranik Ivanov
- grid.6363.00000 0001 2218 4662Core Unit Bioinformatics, Berlin Institute of Health, Charité - University Hospital Berlin, 10117 Berlin, Germany
| | - Nele Sterczyk
- grid.6363.00000 0001 2218 4662Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Neuropathology, Charitéplatz 1, 10117 Berlin, Germany
| | - Shirin Schneeberger
- grid.6363.00000 0001 2218 4662Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Neuropathology, Charitéplatz 1, 10117 Berlin, Germany ,grid.517316.7Cluster of Excellence, NeuroCure, Berlin, Germany ,Present Address: Apollo Health Ventures, Schlüterstr. 36, 10629 Berlin, Germany
| | - Tatiana Borodina
- grid.419491.00000 0001 1014 0849Scientific Genomics Platforms, Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Society, Berlin, Germany and Berlin Institute of Health (BIH), Berlin, Germany
| | - Sascha Sauer
- grid.419491.00000 0001 1014 0849Scientific Genomics Platforms, Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Society, Berlin, Germany and Berlin Institute of Health (BIH), Berlin, Germany
| | - Dieter Beule
- grid.6363.00000 0001 2218 4662Core Unit Bioinformatics, Berlin Institute of Health, Charité - University Hospital Berlin, 10117 Berlin, Germany
| | - Frank L. Heppner
- grid.6363.00000 0001 2218 4662Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Department of Neuropathology, Charitéplatz 1, 10117 Berlin, Germany ,grid.424247.30000 0004 0438 0426German Center for Neurodegenerative Diseases (DZNE) within the Helmholtz Association, Berlin, Germany ,grid.517316.7Cluster of Excellence, NeuroCure, Berlin, Germany
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17
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Chun BJ, Aryal SP, Varughese P, Sun B, Bruno JA, Richards CI, Bachstetter AD, Kekenes-Huskey PM. Purinoreceptors and ectonucleotidases control ATP-induced calcium waveforms and calcium-dependent responses in microglia: Roles of P2 receptors and CD39 in ATP-stimulated microglia. Front Physiol 2023; 13:1037417. [PMID: 36699679 PMCID: PMC9868579 DOI: 10.3389/fphys.2022.1037417] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 12/12/2022] [Indexed: 01/11/2023] Open
Abstract
Adenosine triphosphate (ATP) and its metabolites drive microglia migration and cytokine production by activating P2X- and P2Y- class purinergic receptors. Purinergic receptor activation gives rise to diverse intracellular calcium (Ca2+ signals, or waveforms, that differ in amplitude, duration, and frequency. Whether and how these characteristics of diverse waveforms influence microglia function is not well-established. We developed a computational model trained with data from published primary murine microglia studies. We simulate how purinoreceptors influence Ca2+ signaling and migration, as well as, how purinoreceptor expression modifies these processes. Our simulation confirmed that P2 receptors encode the amplitude and duration of the ATP-induced Ca2+ waveforms. Our simulations also implicate CD39, an ectonucleotidase that rapidly degrades ATP, as a regulator of purinergic receptor-induced Ca2+ responses. Namely, it was necessary to account for CD39 metabolism of ATP to align the model's predicted purinoreceptor responses with published experimental data. In addition, our modeling results indicate that small Ca2+ transients accompany migration, while large and sustained transients are needed for cytokine responses. Lastly, as a proof-of-principal, we predict Ca2+ transients and cell membrane displacements in a BV2 microglia cell line using published P2 receptor mRNA data to illustrate how our computer model may be extrapolated to other microglia subtypes. These findings provide important insights into how differences in purinergic receptor expression influence microglial responses to ATP.
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Affiliation(s)
- Byeong J. Chun
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, IL, United States,*Correspondence: Byeong J. Chun, ; Peter M. Kekenes-Huskey,
| | - Surya P. Aryal
- Department of Chemistry, University of Kentucky, Lexington, KY, United States
| | - Peter Varughese
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, IL, United States
| | - Bin Sun
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, IL, United States
| | - Joshua A. Bruno
- Department of Physics, Loyola University Chicago, Chicago, IL, United States
| | - Chris I. Richards
- Department of Chemistry, University of Kentucky, Lexington, KY, United States
| | | | - Peter M. Kekenes-Huskey
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, IL, United States,*Correspondence: Byeong J. Chun, ; Peter M. Kekenes-Huskey,
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18
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Kruyer A, Kalivas PW, Scofield MD. Astrocyte regulation of synaptic signaling in psychiatric disorders. Neuropsychopharmacology 2023; 48:21-36. [PMID: 35577914 PMCID: PMC9700696 DOI: 10.1038/s41386-022-01338-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/27/2022] [Accepted: 05/01/2022] [Indexed: 02/07/2023]
Abstract
Over the last 15 years, the field of neuroscience has evolved toward recognizing the critical role of astroglia in shaping neuronal synaptic activity and along with the pre- and postsynapse is now considered an equal partner in tripartite synaptic transmission and plasticity. The relative youth of this recognition and a corresponding deficit in reagents and technologies for quantifying and manipulating astroglia relative to neurons continues to hamper advances in understanding tripartite synaptic physiology. Nonetheless, substantial advances have been made and are reviewed herein. We review the role of astroglia in synaptic function and regulation of behavior with an eye on how tripartite synapses figure into brain pathologies underlying behavioral impairments in psychiatric disorders, both from the perspective of measures in postmortem human brains and more subtle influences on tripartite synaptic regulation of behavior in animal models of psychiatric symptoms. Our goal is to provide the reader a well-referenced state-of-the-art understanding of current knowledge and predict what we may discover with deeper investigation of tripartite synapses using reagents and technologies not yet available.
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Affiliation(s)
- Anna Kruyer
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Peter W Kalivas
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, USA.
| | - Michael D Scofield
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA.
- Department of Anesthesia & Perioperative Medicine, Medical University of South Carolina, Charleston, SC, USA.
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19
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de Lima IB, Ribeiro FM. The Implication of Glial Metabotropic Glutamate Receptors in Alzheimer's Disease. Curr Neuropharmacol 2023; 21:164-182. [PMID: 34951388 PMCID: PMC10190153 DOI: 10.2174/1570159x20666211223140303] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 12/05/2021] [Accepted: 12/16/2021] [Indexed: 11/22/2022] Open
Abstract
Alzheimer's disease (AD) was first identified more than 100 years ago, yet aspects pertaining to its origin and the mechanisms underlying disease progression are not well known. To this date, there is no therapeutic approach or disease-modifying drug that could halt or at least delay disease progression. Until recently, glial cells were seen as secondary actors in brain homeostasis. Although this view was gradually refuted and the relevance of glial cells for the most diverse brain functions such as synaptic plasticity and neurotransmission was vastly proved, many aspects of its functioning, as well as its role in pathological conditions, remain poorly understood. Metabotropic glutamate receptors (mGluRs) in glial cells were shown to be involved in neuroinflammation and neurotoxicity. Besides its relevance for glial function, glutamatergic receptors are also central in the pathology of AD, and recent studies have shown that glial mGluRs play a role in the establishment and progression of AD. AD-related alterations in Ca2+ signalling, APP processing, and Aβ load, as well as AD-related neurodegeneration, are influenced by glial mGluRs. However, different types of mGluRs play different roles, depending on the cell type and brain region that is being analysed. Therefore, in this review, we focus on the current understanding of glial mGluRs and their implication in AD, providing an insight for future therapeutics and identifying existing research gaps worth investigating.
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Affiliation(s)
- Izabella B.Q. de Lima
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Fabíola M. Ribeiro
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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20
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Goenaga J, Araque A, Kofuji P, Herrera Moro Chao D. Calcium signaling in astrocytes and gliotransmitter release. Front Synaptic Neurosci 2023; 15:1138577. [PMID: 36937570 PMCID: PMC10017551 DOI: 10.3389/fnsyn.2023.1138577] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/16/2023] [Indexed: 03/06/2023] Open
Abstract
Glia are as numerous in the brain as neurons and widely known to serve supportive roles such as structural scaffolding, extracellular ionic and neurotransmitter homeostasis, and metabolic support. However, over the past two decades, several lines of evidence indicate that astrocytes, which are a type of glia, play active roles in neural information processing. Astrocytes, although not electrically active, can exhibit a form of excitability by dynamic changes in intracellular calcium levels. They sense synaptic activity and release neuroactive substances, named gliotransmitters, that modulate neuronal activity and synaptic transmission in several brain areas, thus impacting animal behavior. This "dialogue" between astrocytes and neurons is embodied in the concept of the tripartite synapse that includes astrocytes as integral elements of synaptic function. Here, we review the recent work and discuss how astrocytes via calcium-mediated excitability modulate synaptic information processing at various spatial and time scales.
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21
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Pittolo S, Yokoyama S, Willoughby DD, Taylor CR, Reitman ME, Tse V, Wu Z, Etchenique R, Li Y, Poskanzer KE. Dopamine activates astrocytes in prefrontal cortex via α1-adrenergic receptors. Cell Rep 2022; 40:111426. [PMID: 36170823 PMCID: PMC9555850 DOI: 10.1016/j.celrep.2022.111426] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 07/19/2022] [Accepted: 09/08/2022] [Indexed: 12/31/2022] Open
Abstract
The prefrontal cortex (PFC) is a hub for cognitive control, and dopamine profoundly influences its functions. In other brain regions, astrocytes sense diverse neurotransmitters and neuromodulators and, in turn, orchestrate regulation of neuroactive substances. However, basic physiology of PFC astrocytes, including which neuromodulatory signals they respond to and how they contribute to PFC function, is unclear. Here, we characterize divergent signaling signatures in mouse astrocytes of the PFC and primary sensory cortex, which show differential responsiveness to locomotion. We find that PFC astrocytes express receptors for dopamine but are unresponsive through the Gs/Gi-cAMP pathway. Instead, fast calcium signals in PFC astrocytes are time locked to dopamine release and are mediated by α1-adrenergic receptors both ex vivo and in vivo. Further, we describe dopamine-triggered regulation of extracellular ATP at PFC astrocyte territories. Thus, we identify astrocytes as active players in dopaminergic signaling in the PFC, contributing to PFC function though neuromodulator receptor crosstalk. Pittolo et al. demonstrate that the neuromodulator dopamine targets astrocytes, a type of brain cell, via receptors specific to another neuromodulator—norepinephrine. This study provides groundwork on how dopamine affects non-neuronal brain cells and suggests that crosstalk between neuromodulatory pathways occurs in vivo, with possible clinical implications.
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Affiliation(s)
- Silvia Pittolo
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Sae Yokoyama
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Drew D Willoughby
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Charlotte R Taylor
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Michael E Reitman
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Vincent Tse
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Zhaofa Wu
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Roberto Etchenique
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CONICET, Intendente Güiraldes 2160, Ciudad Universitaria, Pabellón 2, C1428EGA, Buenos Aires, Argentina
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China
| | - Kira E Poskanzer
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA; Kavli Institute for Fundamental Neuroscience, San Francisco, CA, USA.
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22
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Astrocytic Piezo1-mediated mechanotransduction determines adult neurogenesis and cognitive functions. Neuron 2022; 110:2984-2999.e8. [PMID: 35963237 DOI: 10.1016/j.neuron.2022.07.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 05/31/2022] [Accepted: 07/12/2022] [Indexed: 12/12/2022]
Abstract
Adult brain activities are generally believed to be dominated by chemical and electrical transduction mechanisms. However, the importance of mechanotransduction mediated by mechano-gated ion channels in brain functions is less appreciated. Here, we show that the mechano-gated Piezo1 channel is expressed in the exploratory processes of astrocytes and utilizes its mechanosensitivity to mediate mechanically evoked Ca2+ responses and ATP release, establishing Piezo1-mediated mechano-chemo transduction in astrocytes. Piezo1 deletion in astrocytes causes a striking reduction of hippocampal volume and brain weight and severely impaired (but ATP-rescuable) adult neurogenesis in vivo, and it abolishes ATP-dependent potentiation of neural stem cell (NSC) proliferation in vitro. Piezo1-deficient mice show impaired hippocampal long-term potentiation (LTP) and learning and memory behaviors. By contrast, overexpression of Piezo1 in astrocytes sufficiently enhances mechanotransduction, LTP, and learning and memory performance. Thus, astrocytes utilize Piezo1-mediated mechanotransduction mechanisms to robustly regulate adult neurogenesis and cognitive functions, conceptually highlighting the importance of mechanotransduction in brain structure and function.
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23
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Baudon A, Clauss Creusot E, Althammer F, Schaaf CP, Charlet A. Emerging role of astrocytes in oxytocin-mediated control of neural circuits and brain functions. Prog Neurobiol 2022; 217:102328. [PMID: 35870680 DOI: 10.1016/j.pneurobio.2022.102328] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 07/01/2022] [Accepted: 07/18/2022] [Indexed: 11/19/2022]
Abstract
The neuropeptide oxytocin has been in the focus of scientists for decades due to its profound and pleiotropic effects on physiology, activity of neuronal circuits and behaviors, among which sociality. Until recently, it was believed that oxytocinergic action exclusively occurs through direct activation of neuronal oxytocin receptors. However, several studies demonstrated the existence and functional relevance of astroglial oxytocin receptors in various brain regions in the mouse and rat brain. Astrocytic signaling and activity is critical for many important physiological processes including metabolism, neurotransmitter clearance from the synaptic cleft and integrated brain functions. While it can be speculated that oxytocinergic action on astrocytes predominantly facilitates neuromodulation via the release of specific gliotransmitters, the precise role of astrocytic oxytocin receptors remains elusive. In this review, we discuss the latest studies on the interaction between the oxytocinergic system and astrocytes, including detailed information about intracellular cascades, and speculate about future research directions on astrocytic oxytocin signaling.
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Affiliation(s)
- Angel Baudon
- Centre National de la Recherche Scientifique and University of Strasbourg, Institute of Cellular and Integrative Neuroscience, Strasbourg 67000 France
| | - Etienne Clauss Creusot
- Centre National de la Recherche Scientifique and University of Strasbourg, Institute of Cellular and Integrative Neuroscience, Strasbourg 67000 France
| | | | | | - Alexandre Charlet
- Centre National de la Recherche Scientifique and University of Strasbourg, Institute of Cellular and Integrative Neuroscience, Strasbourg 67000 France.
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24
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Covelo A, Badoual A, Denizot A. Reinforcing Interdisciplinary Collaborations to Unravel the Astrocyte "Calcium Code". J Mol Neurosci 2022; 72:1443-1455. [PMID: 35543801 PMCID: PMC9293817 DOI: 10.1007/s12031-022-02006-w] [Citation(s) in RCA: 4] [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: 12/23/2021] [Accepted: 04/01/2022] [Indexed: 11/19/2022]
Abstract
In this review article, we present the major insights from and challenges faced in the acquisition, analysis and modeling of astrocyte calcium activity, aiming at bridging the gap between those fields to crack the complex astrocyte "Calcium Code". We then propose strategies to reinforce interdisciplinary collaborative projects to unravel astrocyte function in health and disease.
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Affiliation(s)
- Ana Covelo
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1215, NeuroCentre Magendie, 33077, Bordeaux, France
- University of Bordeaux, Bordeaux, 33077, France
| | - Anaïs Badoual
- SERPICO Project-Team, Inria Centre Rennes-Bretagne Atlantique, Rennes Cedex, 35042, France
- SERPICO/STED Team, UMR144 CNRS Institut Curie, PSL Research University, Sorbonne Universités, Paris, 75005, France
| | - Audrey Denizot
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Onna, 904-0495, Japan.
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25
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Georgiou L, Echeverría A, Georgiou A, Kuhn B. Ca + activity maps of astrocytes tagged by axoastrocytic AAV transfer. SCIENCE ADVANCES 2022; 8:eabe5371. [PMID: 35138891 PMCID: PMC8827655 DOI: 10.1126/sciadv.abe5371] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/17/2021] [Indexed: 05/27/2023]
Abstract
Astrocytes exhibit localized Ca2+ microdomain (MD) activity thought to be actively involved in information processing in the brain. However, functional organization of Ca2+ MDs in space and time in relationship to behavior and neuronal activity is poorly understood. Here, we first show that adeno-associated virus (AAV) particles transfer anterogradely from axons to astrocytes. Then, we use this axoastrocytic AAV transfer to express genetically encoded Ca2+ indicators at high-contrast circuit specifically. In combination with two-photon microscopy and unbiased, event-based analysis, we investigated cortical astrocytes embedded in the vibrissal thalamocortical circuit. We found a wide range of Ca2+ MD signals, some of which were ultrafast (≤300 ms). Frequency and size of signals were extensively increased by locomotion but only subtly with sensory stimulation. The overlay of these signals resulted in behavior-dependent maps with characteristic Ca2+ activity hotspots, maybe representing memory engrams. These functional subdomains are stable over days, suggesting subcellular specialization.
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26
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Lyon KA, Allen NJ. From Synapses to Circuits, Astrocytes Regulate Behavior. Front Neural Circuits 2022; 15:786293. [PMID: 35069124 PMCID: PMC8772456 DOI: 10.3389/fncir.2021.786293] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/05/2021] [Indexed: 12/21/2022] Open
Abstract
Astrocytes are non-neuronal cells that regulate synapses, neuronal circuits, and behavior. Astrocytes ensheath neuronal synapses to form the tripartite synapse where astrocytes influence synapse formation, function, and plasticity. Beyond the synapse, recent research has revealed that astrocyte influences on the nervous system extend to the modulation of neuronal circuitry and behavior. Here we review recent findings on the active role of astrocytes in behavioral modulation with a focus on in vivo studies, primarily in mice. Using tools to acutely manipulate astrocytes, such as optogenetics or chemogenetics, studies reviewed here have demonstrated a causal role for astrocytes in sleep, memory, sensorimotor behaviors, feeding, fear, anxiety, and cognitive processes like attention and behavioral flexibility. Current tools and future directions for astrocyte-specific manipulation, including methods for probing astrocyte heterogeneity, are discussed. Understanding the contribution of astrocytes to neuronal circuit activity and organismal behavior will be critical toward understanding how nervous system function gives rise to behavior.
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Affiliation(s)
- Krissy A Lyon
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, United States
| | - Nicola J Allen
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, United States
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27
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Abstract
Drug addiction remains a key biomedical challenge facing current neuroscience research. In addition to neural mechanisms, the focus of the vast majority of studies to date, astrocytes have been increasingly recognized as an "accomplice." According to the tripartite synapse model, astrocytes critically regulate nearby pre- and postsynaptic neuronal substrates to craft experience-dependent synaptic plasticity, including synapse formation and elimination. Astrocytes within brain regions that are implicated in drug addiction exhibit dynamic changes in activity upon exposure to cocaine and subsequently undergo adaptive changes themselves during chronic drug exposure. Recent results have identified several key astrocytic signaling pathways that are involved in cocaine-induced synaptic and circuit adaptations. In this review, we provide a brief overview of the role of astrocytes in regulating synaptic transmission and neuronal function, and discuss how cocaine influences these astrocyte-mediated mechanisms to induce persistent synaptic and circuit alterations that promote cocaine seeking and relapse. We also consider the therapeutic potential of targeting astrocytic substrates to ameliorate drug-induced neuroplasticity for behavioral benefits. While primarily focusing on cocaine-induced astrocytic responses, we also include brief discussion of other drugs of abuse where data are available.
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28
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Ahmadpour N, Kantroo M, Stobart JL. Extracellular Calcium Influx Pathways in Astrocyte Calcium Microdomain Physiology. Biomolecules 2021; 11:1467. [PMID: 34680100 PMCID: PMC8533159 DOI: 10.3390/biom11101467] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 09/25/2021] [Accepted: 10/01/2021] [Indexed: 02/08/2023] Open
Abstract
Astrocytes are complex glial cells that play many essential roles in the brain, including the fine-tuning of synaptic activity and blood flow. These roles are linked to fluctuations in intracellular Ca2+ within astrocytes. Recent advances in imaging techniques have identified localized Ca2+ transients within the fine processes of the astrocytic structure, which we term microdomain Ca2+ events. These Ca2+ transients are very diverse and occur under different conditions, including in the presence or absence of surrounding circuit activity. This complexity suggests that different signalling mechanisms mediate microdomain events which may then encode specific astrocyte functions from the modulation of synapses up to brain circuits and behaviour. Several recent studies have shown that a subset of astrocyte microdomain Ca2+ events occur rapidly following local neuronal circuit activity. In this review, we consider the physiological relevance of microdomain astrocyte Ca2+ signalling within brain circuits and outline possible pathways of extracellular Ca2+ influx through ionotropic receptors and other Ca2+ ion channels, which may contribute to astrocyte microdomain events with potentially fast dynamics.
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Affiliation(s)
| | | | - Jillian L. Stobart
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, 750 McDermot Avenue, Winnipeg, MG R3E 0T5, Canada; (N.A.); (M.K.)
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29
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Weiss S, Clamon LC, Manoim JE, Ormerod KG, Parnas M, Littleton JT. Glial ER and GAP junction mediated Ca 2+ waves are crucial to maintain normal brain excitability. Glia 2021; 70:123-144. [PMID: 34528727 DOI: 10.1002/glia.24092] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 08/29/2021] [Accepted: 08/30/2021] [Indexed: 11/08/2022]
Abstract
Astrocytes play key roles in regulating multiple aspects of neuronal function from invertebrates to humans and display Ca2+ fluctuations that are heterogeneously distributed throughout different cellular microdomains. Changes in Ca2+ dynamics represent a key mechanism for how astrocytes modulate neuronal activity. An unresolved issue is the origin and contribution of specific glial Ca2+ signaling components at distinct astrocytic domains to neuronal physiology and brain function. The Drosophila model system offers a simple nervous system that is highly amenable to cell-specific genetic manipulations to characterize the role of glial Ca2+ signaling. Here we identify a role for ER store-operated Ca2+ entry (SOCE) pathway in perineurial glia (PG), a glial population that contributes to the Drosophila blood-brain barrier. We show that PG cells display diverse Ca2+ activity that varies based on their locale within the brain. Ca2+ signaling in PG cells does not require extracellular Ca2+ and is blocked by inhibition of SOCE, Ryanodine receptors, or gap junctions. Disruption of these components triggers stimuli-induced seizure-like episodes. These findings indicate that Ca2+ release from internal stores and its propagation between neighboring glial cells via gap junctions are essential for maintaining normal nervous system function.
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Affiliation(s)
- Shirley Weiss
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Lauren C Clamon
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Julia E Manoim
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Kiel G Ormerod
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Moshe Parnas
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - J Troy Littleton
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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30
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Dunn TW, Sossin WS. Excitatory postsynaptic calcium transients at Aplysia sensory-motor neuron synapses allow for quantal examination of synaptic strength over multiple days in culture. ACTA ACUST UNITED AC 2021; 28:277-290. [PMID: 34400529 PMCID: PMC8372562 DOI: 10.1101/lm.052639.120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 06/26/2021] [Indexed: 12/21/2022]
Abstract
A more thorough description of the changes in synaptic strength underlying synaptic plasticity may be achieved with quantal resolution measurements at individual synaptic sites. Here, we demonstrate that by using a membrane targeted genetic calcium sensor, we can measure quantal synaptic events at the individual synaptic sites of Aplysia sensory neuron to motor neuron synaptic connections. These results show that synaptic strength is not evenly distributed between all contacts in these cultures, but dominated by multiquantal sites of synaptic contact, likely clusters of individual synaptic sites. Surprisingly, most synaptic contacts were not found opposite presynaptic varicosities, but instead at areas of pre- and postsynaptic contact with no visible thickening of membranes. The release probability, quantal size, and quantal content can be measured over days at individual synaptic contacts using this technique. Homosynaptic depression was accompanied by a reduction in release site probability, with no evidence of individual synaptic site silencing over the course of depression. This technique shows promise in being able to address outstanding questions in this system, including determining the synaptic changes that maintain long-term alterations in synaptic strength that underlie memory.
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Affiliation(s)
- Tyler W Dunn
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Wayne S Sossin
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
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31
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Lim EY, Ye L, Paukert M. Potential and Realized Impact of Astroglia Ca 2 + Dynamics on Circuit Function and Behavior. Front Cell Neurosci 2021; 15:682888. [PMID: 34163330 PMCID: PMC8215280 DOI: 10.3389/fncel.2021.682888] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/03/2021] [Indexed: 11/13/2022] Open
Abstract
Astroglia display a wide range of spontaneous and behavioral state-dependent Ca2+ dynamics. During heightened vigilance, noradrenergic signaling leads to quasi-synchronous Ca2+ elevations encompassing soma and processes across the brain-wide astroglia network. Distinct from this vigilance-associated global Ca2+ rise are apparently spontaneous fluctuations within spatially restricted microdomains. Over the years, several strategies have been pursued to shed light on the physiological impact of these signals including deletion of endogenous ion channels or receptors and reduction of intracellular Ca2+ through buffering, extrusion or inhibition of release. Some experiments that revealed the most compelling behavioral alterations employed chemogenetic and optogenetic manipulations to modify astroglia Ca2+ signaling. However, there is considerable contrast between these findings and the comparatively modest effects of inhibiting endogenous sources of Ca2+. In this review, we describe the underlying mechanisms of various forms of astroglia Ca2+ signaling as well as the functional consequences of their inhibition. We then discuss how the effects of exogenous astroglia Ca2+ modification combined with our knowledge of physiological mechanisms of astroglia Ca2+ activation could guide further refinement of behavioral paradigms that will help elucidate the natural Ca2+-dependent function of astroglia.
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Affiliation(s)
- Eunice Y. Lim
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States,Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Liang Ye
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Martin Paukert
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States,Center for Biomedical Neuroscience, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States,*Correspondence: Martin Paukert,
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32
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Lim D, Semyanov A, Genazzani A, Verkhratsky A. Calcium signaling in neuroglia. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 362:1-53. [PMID: 34253292 DOI: 10.1016/bs.ircmb.2021.01.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glial cells exploit calcium (Ca2+) signals to perceive the information about the activity of the nervous tissue and the tissue environment to translate this information into an array of homeostatic, signaling and defensive reactions. Astrocytes, the best studied glial cells, use several Ca2+ signaling generation pathways that include Ca2+ entry through plasma membrane, release from endoplasmic reticulum (ER) and from mitochondria. Activation of metabotropic receptors on the plasma membrane of glial cells is coupled to an enzymatic cascade in which a second messenger, InsP3 is generated thus activating intracellular Ca2+ release channels in the ER endomembrane. Astrocytes also possess store-operated Ca2+ entry and express several ligand-gated Ca2+ channels. In vivo astrocytes generate heterogeneous Ca2+ signals, which are short and frequent in distal processes, but large and relatively rare in soma. In response to neuronal activity intracellular and inter-cellular astrocytic Ca2+ waves can be produced. Astrocytic Ca2+ signals are involved in secretion, they regulate ion transport across cell membranes, and are contributing to cell morphological plasticity. Therefore, astrocytic Ca2+ signals are linked to fundamental functions of the central nervous system ranging from synaptic transmission to behavior. In oligodendrocytes, Ca2+ signals are generated by plasmalemmal Ca2+ influx, or by release from intracellular stores, or by combination of both. Microglial cells exploit Ca2+ permeable ionotropic purinergic receptors and transient receptor potential channels as well as ER Ca2+ release. In this contribution, basic morphology of glial cells, glial Ca2+ signaling toolkit, intracellular Ca2+ signals and Ca2+-regulated functions are discussed with focus on astrocytes.
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Affiliation(s)
- Dmitry Lim
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Novara, Italy.
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia; Faculty of Biology, Moscow State University, Moscow, Russia; Sechenov First Moscow State Medical University, Moscow, Russia
| | - Armando Genazzani
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Novara, Italy
| | - Alexei Verkhratsky
- Sechenov First Moscow State Medical University, Moscow, Russia; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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33
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Pham C, Hérault K, Oheim M, Maldera S, Vialou V, Cauli B, Li D. Astrocytes respond to a neurotoxic Aβ fragment with state-dependent Ca 2+ alteration and multiphasic transmitter release. Acta Neuropathol Commun 2021; 9:44. [PMID: 33726852 PMCID: PMC7968286 DOI: 10.1186/s40478-021-01146-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/28/2021] [Indexed: 12/13/2022] Open
Abstract
Excessive amounts of amyloid β (Aβ) peptide have been suggested to dysregulate synaptic transmission in Alzheimer's disease (AD). As a major type of glial cell in the mammalian brain, astrocytes regulate neuronal function and undergo activity alterations upon Aβ exposure. Yet the mechanistic steps underlying astrocytic responses to Aβ peptide remain to be elucidated. Here by fluorescence imaging of signaling pathways, we dissected astrocytic responses to Aβ25-35 peptide, a neurotoxic Aβ fragment present in AD patients. In native health astrocytes, Aβ25-35 evoked Ca2+ elevations via purinergic receptors, being also dependent on the opening of connexin (CX) hemichannels. Aβ25-35, however, induced a Ca2+ diminution in Aβ-preconditioned astrocytes as a result of the potentiation of the plasma membrane Ca2+ ATPase (PMCA). The PMCA and CX protein expression was observed with immunostaining in the brain tissue of hAPPJ20 AD mouse model. We also observed both Ca2+-independent and Ca2+-dependent glutamate release upon astrocytic Aβ exposure, with the former mediated by CX hemichannel and the latter by both anion channels and lysosome exocytosis. Our results suggest that Aβ peptide causes state-dependent responses in astrocytes, in association with a multiphasic release of signaling molecules. This study therefore helps to understand astrocyte engagement in AD-related amyloidopathy.
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34
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Gipson CD, Rawls S, Scofield MD, Siemsen BM, Bondy EO, Maher EE. Interactions of neuroimmune signaling and glutamate plasticity in addiction. J Neuroinflammation 2021; 18:56. [PMID: 33612110 PMCID: PMC7897396 DOI: 10.1186/s12974-021-02072-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 01/05/2021] [Indexed: 02/28/2023] Open
Abstract
Chronic use of drugs of abuse affects neuroimmune signaling; however, there are still many open questions regarding the interactions between neuroimmune mechanisms and substance use disorders (SUDs). Further, chronic use of drugs of abuse can induce glutamatergic changes in the brain, but the relationship between the glutamate system and neuroimmune signaling in addiction is not well understood. Therefore, the purpose of this review is to bring into focus the role of neuroimmune signaling and its interactions with the glutamate system following chronic drug use, and how this may guide pharmacotherapeutic treatment strategies for SUDs. In this review, we first describe neuroimmune mechanisms that may be linked to aberrant glutamate signaling in addiction. We focus specifically on the nuclear factor-kappa B (NF-κB) pathway, a potentially important neuroimmune mechanism that may be a key player in driving drug-seeking behavior. We highlight the importance of astroglial-microglial crosstalk, and how this interacts with known glutamatergic dysregulations in addiction. Then, we describe the importance of studying non-neuronal cells with unprecedented precision because understanding structure-function relationships in these cells is critical in understanding their role in addiction neurobiology. Here we propose a working model of neuroimmune-glutamate interactions that underlie drug use motivation, which we argue may aid strategies for small molecule drug development to treat substance use disorders. Together, the synthesis of this review shows that interactions between glutamate and neuroimmune signaling may play an important and understudied role in addiction processes and may be critical in developing more efficacious pharmacotherapies to treat SUDs.
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Affiliation(s)
- Cassandra D Gipson
- Department of Family and Community Medicine, University of Kentucky, 741 S. Limestone, BBSRB, Room 363, Lexington, KY, 40536-0509, USA.
| | - Scott Rawls
- Department of Pharmacology, Lewis Katz School of Medicine, Temple University, Philadelphia, USA
| | - Michael D Scofield
- Department of Anesthesiology, Medical University of South Carolina, Charleston, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, USA
| | - Benjamin M Siemsen
- Department of Anesthesiology, Medical University of South Carolina, Charleston, USA
| | - Emma O Bondy
- Department of Family and Community Medicine, University of Kentucky, 741 S. Limestone, BBSRB, Room 363, Lexington, KY, 40536-0509, USA
| | - Erin E Maher
- Department of Family and Community Medicine, University of Kentucky, 741 S. Limestone, BBSRB, Room 363, Lexington, KY, 40536-0509, USA
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35
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Exacerbation of Epilepsy by Astrocyte Alkalization and Gap Junction Uncoupling. J Neurosci 2021; 41:2106-2118. [PMID: 33478985 DOI: 10.1523/jneurosci.2365-20.2020] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/02/2020] [Accepted: 11/25/2020] [Indexed: 12/12/2022] Open
Abstract
Seizures invite seizures. At the initial stage of epilepsy, seizures intensify with each episode; however, the mechanisms underlying this exacerbation remain to be solved. Astrocytes have a strong control over neuronal excitability and the mode of information processing. This control is accomplished by adjusting the levels of various ions in the extracellular space. The network of astrocytes connected via gap junctions allows a wider or more confined distribution of these ions depending on the open probability of the gap junctions. K+ clearance relies on the K+ uptake by astrocytes and the subsequent diffusion of K+ through the astrocyte network. When astrocytes become uncoupled, K+ clearance becomes hindered. Accumulation of extracellular K+ leads to hyperexcitability of neurons. Here, using acute hippocampal slices from mice, we uncovered that brief periods of epileptiform activity result in gap junction uncoupling. In slices that experienced short-term epileptiform activity, extracellular K+ transients in response to glutamate became prolonged. Na+ imaging with a fluorescent indicator indicated that intercellular diffusion of small cations in the astrocytic syncytium via gap junctions became rapidly restricted after epileptiform activity. Using a transgenic mouse with astrocyte-specific expression of a pH sensor (Lck-E2GFP), we confirmed that astrocytes react to epileptiform activity with intracellular alkalization. Application of Na+/HCO3 - cotransporter blocker led to the suppression of intracellular alkalization of astrocytes and to the prevention of astrocyte uncoupling and hyperactivity intensification both in vitro and in vivo Therefore, the inhibition of astrocyte alkalization could become a promising therapeutic strategy for countering epilepsy development.SIGNIFICANCE STATEMENT We aimed to understand the mechanisms underlying the plastic change of forebrain circuits associated with the intensification of epilepsy. Here, we demonstrate that first-time exposure to only brief periods of epileptiform activity results in acute disturbance of the intercellular astrocyte network formed by gap junctions in hippocampal tissue slices from mice. Moreover, rapid clearance of K+ from the extracellular space was impaired. Epileptiform activity activated inward Na+/HCO3 - cotransport in astrocytes by cell depolarization, resulting in their alkalization. Our data suggest that alkaline pH shifts in astrocytes lead to gap junction uncoupling, hampering K+ clearance, and thereby to exacerbation of epilepsy. Pharmacological intervention could become a promising new strategy to dampen neuronal hyperexcitability and epileptogenesis.
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36
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Perez-Catalan NA, Doe CQ, Ackerman SD. The role of astrocyte-mediated plasticity in neural circuit development and function. Neural Dev 2021; 16:1. [PMID: 33413602 PMCID: PMC7789420 DOI: 10.1186/s13064-020-00151-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/26/2020] [Indexed: 02/03/2023] Open
Abstract
Neuronal networks are capable of undergoing rapid structural and functional changes called plasticity, which are essential for shaping circuit function during nervous system development. These changes range from short-term modifications on the order of milliseconds, to long-term rearrangement of neural architecture that could last for the lifetime of the organism. Neural plasticity is most prominent during development, yet also plays a critical role during memory formation, behavior, and disease. Therefore, it is essential to define and characterize the mechanisms underlying the onset, duration, and form of plasticity. Astrocytes, the most numerous glial cell type in the human nervous system, are integral elements of synapses and are components of a glial network that can coordinate neural activity at a circuit-wide level. Moreover, their arrival to the CNS during late embryogenesis correlates to the onset of sensory-evoked activity, making them an interesting target for circuit plasticity studies. Technological advancements in the last decade have uncovered astrocytes as prominent regulators of circuit assembly and function. Here, we provide a brief historical perspective on our understanding of astrocytes in the nervous system, and review the latest advances on the role of astroglia in regulating circuit plasticity and function during nervous system development and homeostasis.
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Affiliation(s)
- Nelson A Perez-Catalan
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, USA
- Kennedy Center, Department of Pediatrics, The University of Chicago, Chicago, IL, USA
| | - Chris Q Doe
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, USA
| | - Sarah D Ackerman
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, USA.
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37
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Schmidt E, Oheim M. Infrared Excitation Induces Heating and Calcium Microdomain Hyperactivity in Cortical Astrocytes. Biophys J 2020; 119:2153-2165. [PMID: 33130118 DOI: 10.1016/j.bpj.2020.10.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 10/01/2020] [Accepted: 10/07/2020] [Indexed: 11/16/2022] Open
Abstract
Unraveling how neural networks process and represent sensory information and how these cellular signals instruct behavioral output is a main goal in neuroscience. Two-photon activation of optogenetic actuators and calcium (Ca2+) imaging with genetically encoded indicators allow, respectively, the all-optical stimulation and readout of activity from genetically identified cell populations. However, these techniques locally expose the brain to high near-infrared light doses, raising the concern of light-induced adverse effects on the biology under study. Combining 2P imaging of Ca2+ transients in GCaMP6f-expressing cortical astrocytes and unbiased machine-based event detection, we demonstrate the subtle build-up of aberrant microdomain Ca2+ transients in the fine astroglial processes that depended on the average rather than peak laser power. Illumination conditions routinely being used in biological 2P microscopy (920-nm excitation, ∼100-fs, and ∼10 mW average power) increased the frequency of microdomain Ca2+ events but left their amplitude, area, and duration largely unchanged. Ca2+ transients in the otherwise silent soma were secondary to this peripheral hyperactivity that occurred without overt morphological damage. Continuous-wave (nonpulsed) 920-nm illumination at the same average power was as damaging as femtosecond pulses, unraveling the dominance of a heating-mediated damage mechanism. In an astrocyte-specific inositol 3-phosphate receptor type-2 knockout mouse, near-infrared light-induced Ca2+ microdomains persisted in the small processes, underpinning their resemblance to physiological inositol 3-phosphate receptor type-2-independent Ca2+ signals, whereas somatic hyperactivity was abolished. We conclude that, contrary to what has generally been believed in the field, shorter pulses and lower average power can help to alleviate damage and allow for longer recording windows at 920 nm.
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Affiliation(s)
- Elke Schmidt
- Université de Paris, SPPIN - Saints-Pères Paris Institute for the Neurosciences, CNRS, Paris, France
| | - Martin Oheim
- Université de Paris, SPPIN - Saints-Pères Paris Institute for the Neurosciences, CNRS, Paris, France.
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38
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Testen A, Kim R, Reissner KJ. High-Resolution Three-Dimensional Imaging of Individual Astrocytes Using Confocal Microscopy. ACTA ACUST UNITED AC 2020; 91:e92. [PMID: 32068976 DOI: 10.1002/cpns.92] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Astrocytes play numerous vital roles in the central nervous system. Accordingly, it is of merit to identify structural and functional properties of astrocytes in both health and disease. The majority of studies examining the morphology of astrocytes have employed immunoassays for markers such as glial fibrillary acidic protein, which are insufficient to encapsulate the considerable structural complexity of these cells. Herein, we describe a method utilizing a commercially available and validated, genetically encoded membrane-associated fluorescent marker of astrocytes, AAV5-GfaABC1D-Lck-GFP. This tool and approach allow for visualization of a single isolated astrocyte in its entirety, including fine peripheral processes. Astrocytes are imaged using confocal microscopy and reconstructed in three dimensions to obtain detailed morphometric data. We further provide an immunohistochemistry procedure to assess colocalization of isolated astrocytes with synaptic markers throughout the z-plane. This technique, which can be utilized via a standard laboratory confocal microscope and Imaris software, allows for detailed analysis of the morphology and synaptic colocalization of astrocytes in fixed tissue. © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Microinjection of AAV5-GfaABC1D-Lck-GFP into the nucleus accumbens of rats Basic Protocol 2: Tissue processing and immunohistochemistry for post-synaptic density-95 Basic Protocol 3: Single-cell image acquisition Basic Protocol 4: Three-dimensional reconstruction of single cells Basic Protocol 5: Three-dimensional colocalization analysis.
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Affiliation(s)
- Anze Testen
- Neuroscience Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Ronald Kim
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Kathryn J Reissner
- Neuroscience Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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39
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Verkhratsky A, Semyanov A, Zorec R. Physiology of Astroglial Excitability. FUNCTION (OXFORD, ENGLAND) 2020; 1:zqaa016. [PMID: 35330636 PMCID: PMC8788756 DOI: 10.1093/function/zqaa016] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 08/29/2020] [Accepted: 09/03/2020] [Indexed: 01/06/2023]
Abstract
Classic physiology divides all neural cells into excitable neurons and nonexcitable neuroglia. Neuroglial cells, chiefly responsible for homeostasis and defense of the nervous tissue, coordinate their complex homeostatic responses with neuronal activity. This coordination reflects a specific form of glial excitability mediated by complex changes in intracellular concentration of ions and second messengers organized in both space and time. Astrocytes are equipped with multiple molecular cascades, which are central for regulating homeostasis of neurotransmitters, ionostasis, synaptic connectivity, and metabolic support of the central nervous system. Astrocytes are further provisioned with multiple receptors for neurotransmitters and neurohormones, which upon activation trigger intracellular signals mediated by Ca2+, Na+, and cyclic AMP. Calcium signals have distinct organization and underlying mechanisms in different astrocytic compartments thus allowing complex spatiotemporal signaling. Signals mediated by fluctuations in cytosolic Na+ are instrumental for coordination of Na+ dependent astrocytic transporters with tissue state and homeostatic demands. Astroglial ionic excitability may also involve K+, H+, and Cl-. The cyclic AMP signalling system is, in comparison to ions, much slower in targeting astroglial effector mechanisms. This evidence review summarizes the concept of astroglial intracellular excitability.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK,Achucarro Center for Neuroscience, Ikerbasque, 48011 Bilbao, Spain,Address correspondence to A.V. (e-mail: )
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia,Faculty of Biology, Moscow State University, Moscow, Russia,Sechenov First Moscow State Medical University, Moscow, Russia
| | - Robert Zorec
- Celica Biomedical, Ljubljana 1000, Slovenia,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana 1000, Slovenia
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40
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Semyanov A, Henneberger C, Agarwal A. Making sense of astrocytic calcium signals — from acquisition to interpretation. Nat Rev Neurosci 2020; 21:551-564. [DOI: 10.1038/s41583-020-0361-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2020] [Indexed: 12/31/2022]
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41
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Gruteser N, Kohlhas V, Balfanz S, Franzen A, Günther A, Offenhäusser A, Müller F, Nikolaev V, Lohse MJ, Baumann A. Establishing a sensitive fluorescence-based quantification method for cyclic nucleotides. BMC Biotechnol 2020; 20:47. [PMID: 32854679 PMCID: PMC7450941 DOI: 10.1186/s12896-020-00633-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/21/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Approximately 40% of prescribed drugs exert their activity via GTP-binding protein-coupled receptors (GPCRs). Once activated, these receptors cause transient changes in the concentration of second messengers, e.g., cyclic adenosine 3',5'-monophosphate (cAMP). Specific and efficacious genetically encoded biosensors have been developed to monitor cAMP fluctuations with high spatial and temporal resolution in living cells or tissue. A well characterized biosensor for cAMP is the Förster resonance energy transfer (FRET)-based Epac1-camps protein. Pharmacological characterization of newly developed ligands acting at GPCRs often includes numerical quantification of the second messenger amount that was produced. RESULTS To quantify cellular cAMP concentrations, we bacterially over-expressed and purified Epac1-camps and applied the purified protein in a cell-free detection assay for cAMP in a multi-well format. We found that the biosensor can detect as little as 0.15 pmol of cAMP, and that the sensitivity is not impaired by non-physiological salt concentrations or pH values. Notably, the assay tolerated desiccation and storage of the protein without affecting Epac1-camps cyclic nucleotide sensitivity. CONCLUSIONS We found that determination cAMP in lysates obtained from cell assays or tissue samples by purified Epac1-camps is a robust, fast, and sensitive assay suitable for routine and high throughput analyses.
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Affiliation(s)
- Nadine Gruteser
- Institute of Biological Information Processing (Molecular and Cellular Physiology, IBI-1), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Viktoria Kohlhas
- Institute of Biological Information Processing (Molecular and Cellular Physiology, IBI-1), Forschungszentrum Jülich, 52428, Jülich, Germany.,Present address: CECAD Research Center, 50931, Cologne, Germany
| | - Sabine Balfanz
- Institute of Biological Information Processing (Molecular and Cellular Physiology, IBI-1), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Arne Franzen
- Institute of Biological Information Processing (Molecular and Cellular Physiology, IBI-1), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Anne Günther
- Institute of Biological Information Processing (Molecular and Cellular Physiology, IBI-1), Forschungszentrum Jülich, 52428, Jülich, Germany.,Present address: RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan
| | - Andreas Offenhäusser
- Institute of Biological Information Processing (Bioelectronics, IBI-3), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Frank Müller
- Institute of Biological Information Processing (Molecular and Cellular Physiology, IBI-1), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Viacheslav Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Martin J Lohse
- Institute of Pharmacology and Toxicology, University of Würzburg, 97078, Würzburg, Germany.,Max Delbrück Center for Molecular Medicine, 13125, Berlin, Germany
| | - Arnd Baumann
- Institute of Biological Information Processing (Molecular and Cellular Physiology, IBI-1), Forschungszentrum Jülich, 52428, Jülich, Germany.
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42
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Pham C, Moro DH, Mouffle C, Didienne S, Hepp R, Pfrieger FW, Mangin JM, Legendre P, Martin C, Luquet S, Cauli B, Li D. Mapping astrocyte activity domains by light sheet imaging and spatio-temporal correlation screening. Neuroimage 2020; 220:117069. [PMID: 32585347 DOI: 10.1016/j.neuroimage.2020.117069] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 02/08/2023] Open
Abstract
Astrocytes are a major type of glial cell in the mammalian brain, essentially regulating neuronal development and function. Quantitative imaging represents an important approach to study astrocytic signaling in neural circuits. Focusing on astrocytic Ca2+ activity, a key pathway implicated in astrocye-neuron interaction, we here report a strategy combining fast light sheet fluorescence microscopy (LSFM) and correlative screening-based time series analysis, to map activity domains in astrocytes in living mammalian nerve tissue. Light sheet of micron-scale thickness enables wide-field optical sectioning to image astrocytes in acute mouse brain slices. Using both chemical and genetically encoded Ca2+ indicators, we demonstrate the complementary advantages of LSFM in mapping Ca2+ domains in astrocyte populations as compared to epifluorescence and two-photon microscopy. Our approach then revealed distinct kinetics of Ca2+ signals between cortical and hypothalamic astrocytes in resting conditions and following the activation of adrenergic G protein coupled receptor (GPCR). This observation highlights the activity heterogeneity across regionally distinct astrocyte populations, and indicates the potential of our method for investigating dynamic signals in astrocytes.
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Affiliation(s)
- Cuong Pham
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Daniela Herrera Moro
- Unité de Biologie Fonctionnelle et Adaptative, Centre National la Recherche Scientifique, Unité Mixte de Recherche 8251, Université Paris Diderot, Sorbonne Paris Cité, 75205, Paris, France
| | - Christine Mouffle
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Steve Didienne
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Régine Hepp
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Frank W Pfrieger
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, F-67000, Strasbourg, France
| | - Jean-Marie Mangin
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Pascal Legendre
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Claire Martin
- Unité de Biologie Fonctionnelle et Adaptative, Centre National la Recherche Scientifique, Unité Mixte de Recherche 8251, Université Paris Diderot, Sorbonne Paris Cité, 75205, Paris, France
| | - Serge Luquet
- Unité de Biologie Fonctionnelle et Adaptative, Centre National la Recherche Scientifique, Unité Mixte de Recherche 8251, Université Paris Diderot, Sorbonne Paris Cité, 75205, Paris, France
| | - Bruno Cauli
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France
| | - Dongdong Li
- Sorbonne Université, Institute of Biology Paris Seine, Neuroscience Paris Seine, CNRS UMR8246, INSERM U1130, UPMC UMCR18, Paris, 75005, France.
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43
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Bannai H, Niwa F, Sakuragi S, Mikoshiba K. Inhibitory synaptic transmission tuned by Ca 2+ and glutamate through the control of GABA A R lateral diffusion dynamics. Dev Growth Differ 2020; 62:398-406. [PMID: 32329058 PMCID: PMC7496684 DOI: 10.1111/dgd.12667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/08/2020] [Accepted: 04/18/2020] [Indexed: 11/30/2022]
Abstract
The GABAergic synapses, a primary inhibitory synapse in the mammalian brain, is important for the normal development of brain circuits, and for the regulation of the excitation‐inhibition balance critical for brain function from the developmental stage throughout life. However, the molecular mechanism underlying the formation, maintenance, and modulation of GABAergic synapses is less understood compared to that of excitatory synapses. Quantum dot‐single particle tracking (QD‐SPT), a super‐resolution imaging technique that enables the analysis of membrane molecule dynamics at single‐molecule resolution, is a powerful tool to analyze the behavior of proteins and lipids on the plasma membrane. In this review, we summarize the recent application of QD‐SPT in understanding of GABAergic synaptic transmission. Here we introduce QD‐SPT experiments that provide further insights into the molecular mechanism supporting GABAergic synapses. QD‐SPT studies revealed that glutamate and Ca2+ signaling is involved in (a) the maintenance of GABAergic synapses, (b) GABAergic long‐term depression, and GABAergic long‐term potentiation, by specifically activating signaling pathways unique to each phenomenon. We also introduce a novel Ca2+ imaging technique to describe the diversity of Ca2+ signals that may activate the downstream signaling pathways that induce specific biological output.
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Affiliation(s)
- Hiroko Bannai
- School of Advanced Science and Engineering, Department of Electrical Engineering and Biosciences, Waseda University, Tokyo, Japan.,Department of Neurophysiology, Keio University School of Medicine, Tokyo, Japan.,Japan Science and Technology Agency, PRESTO, Kawaguchi, Saitama, Japan.,Laboratory for Developmental Neurobiology, RIKEN Center for Brain Science, Wako, Japan
| | - Fumihiro Niwa
- Laboratory for Developmental Neurobiology, RIKEN Center for Brain Science, Wako, Japan.,Institut de Biologie de l'ENS (IBENS), École Normale Supérieure, PSL Research University, INSERM, CNRS, Paris, France
| | - Shigeo Sakuragi
- School of Advanced Science and Engineering, Department of Electrical Engineering and Biosciences, Waseda University, Tokyo, Japan.,Department of Pharmacology, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, RIKEN Center for Brain Science, Wako, Japan.,Shanghai Institute for Advanced Immunochemical Studies (SIAIS), ShanghaiTech University, Shanghai, China.,Department of Biomolecular Science, Faculty of Science, Toho University, Funabashi, Japan
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44
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Abstract
Astrocytes are morphologically complex, ubiquitous cells that are viewed as a homogeneous population tiling the entire central nervous system (CNS). However, this view has been challenged in the last few years with the availability of RNA sequencing, immunohistochemistry, electron microscopy, morphological reconstruction, and imaging data. These studies suggest that astrocytes represent a diverse population of cells and that they display brain area- and disease-specific properties and functions. In this review, we summarize these observations, emphasize areas where clear conclusions can be made, and discuss potential unifying themes. We also identify knowledge gaps that need to be addressed in order to exploit astrocyte diversity as a biological phenomenon of physiological relevance in the CNS. We thus provide a summary and a perspective on astrocyte diversity in the vertebrate CNS.
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Affiliation(s)
- Baljit S Khakh
- Departments of Physiology and Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA;
| | - Benjamin Deneen
- Department of Neuroscience and Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030, USA;
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45
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Pestana F, Edwards-Faret G, Belgard TG, Martirosyan A, Holt MG. No Longer Underappreciated: The Emerging Concept of Astrocyte Heterogeneity in Neuroscience. Brain Sci 2020; 10:brainsci10030168. [PMID: 32183137 PMCID: PMC7139801 DOI: 10.3390/brainsci10030168] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/02/2020] [Accepted: 03/05/2020] [Indexed: 12/18/2022] Open
Abstract
Astrocytes are ubiquitous in the central nervous system (CNS). These cells possess thousands of individual processes, which extend out into the neuropil, interacting with neurons, other glia and blood vessels. Paralleling the wide diversity of their interactions, astrocytes have been reported to play key roles in supporting CNS structure, metabolism, blood-brain-barrier formation and control of vascular blood flow, axon guidance, synapse formation and modulation of synaptic transmission. Traditionally, astrocytes have been studied as a homogenous group of cells. However, recent studies have uncovered a surprising degree of heterogeneity in their development and function, in both the healthy and diseased brain. A better understanding of astrocyte heterogeneity is urgently needed to understand normal brain function, as well as the role of astrocytes in response to injury and disease.
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Affiliation(s)
- Francisco Pestana
- Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research, 3000 Leuven, Belgium;
| | - Gabriela Edwards-Faret
- Laboratory of Neuronal Wiring, VIB-KU Leuven Center for Brain and Disease Research, 3000 Leuven, Belgium;
- Life & Medical Sciences (LIMES) Institute, Faculty of Mathematics and Natural Sciences, University of Bonn, 53115 Bonn, Germany
| | | | - Araks Martirosyan
- Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research, 3000 Leuven, Belgium;
- Correspondence: (A.M.); (M.G.H.); Tel.: +32-16-37-31-27 (M.G.H.)
| | - Matthew G. Holt
- Laboratory of Glia Biology, VIB-KU Leuven Center for Brain and Disease Research, 3000 Leuven, Belgium;
- Leuven Brain Institute, KU Leuven, 3000 Leuven, Belgium
- Correspondence: (A.M.); (M.G.H.); Tel.: +32-16-37-31-27 (M.G.H.)
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46
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King CM, Bohmbach K, Minge D, Delekate A, Zheng K, Reynolds J, Rakers C, Zeug A, Petzold GC, Rusakov DA, Henneberger C. Local Resting Ca 2+ Controls the Scale of Astroglial Ca 2+ Signals. Cell Rep 2020; 30:3466-3477.e4. [PMID: 32160550 PMCID: PMC7068654 DOI: 10.1016/j.celrep.2020.02.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 12/21/2019] [Accepted: 02/06/2020] [Indexed: 02/07/2023] Open
Abstract
Astroglia regulate neurovascular coupling while engaging in signal exchange with neurons. The underlying cellular machinery is thought to rely on astrocytic Ca2+ signals, but what controls their amplitude and waveform is poorly understood. Here, we employ time-resolved two-photon excitation fluorescence imaging in acute hippocampal slices and in cortex in vivo to find that resting [Ca2+] predicts the scale (amplitude) and the maximum (peak) of astroglial Ca2+ elevations. We bidirectionally manipulate resting [Ca2+] by uncaging intracellular Ca2+ or Ca2+ buffers and use ratiometric imaging of a genetically encoded Ca2+ indicator to establish that alterations in resting [Ca2+] change co-directionally the peak level and anti-directionally the amplitude of local Ca2+ transients. This relationship holds for spontaneous and for induced (for instance by locomotion) Ca2+ signals. Our findings uncover a basic generic rule of Ca2+ signal formation in astrocytes, thus also associating the resting Ca2+ level with the physiological "excitability" state of astroglia.
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Affiliation(s)
- Claire M King
- Institute of Neurology, University College London, London, UK
| | - Kirsten Bohmbach
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Daniel Minge
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Andrea Delekate
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Kaiyu Zheng
- Institute of Neurology, University College London, London, UK
| | - James Reynolds
- Institute of Neurology, University College London, London, UK
| | - Cordula Rakers
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Andre Zeug
- Cellular Neurophysiology, Hannover Medical School, Hannover, Germany
| | - Gabor C Petzold
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany; Department of Neurology, University Hospital Bonn, Bonn, Germany
| | | | - Christian Henneberger
- Institute of Neurology, University College London, London, UK; Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
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47
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Yu X, Nagai J, Khakh BS. Improved tools to study astrocytes. Nat Rev Neurosci 2020; 21:121-138. [DOI: 10.1038/s41583-020-0264-8] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2020] [Indexed: 12/21/2022]
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48
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Distinct temporal integration of noradrenaline signaling by astrocytic second messengers during vigilance. Nat Commun 2020; 11:471. [PMID: 31980655 PMCID: PMC6981284 DOI: 10.1038/s41467-020-14378-x] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 12/17/2019] [Indexed: 01/12/2023] Open
Abstract
Astrocytes may function as mediators of the impact of noradrenaline on neuronal function. Activation of glial α1-adrenergic receptors triggers rapid astrocytic Ca2+ elevation and facilitates synaptic plasticity, while activation of β-adrenergic receptors elevates cAMP levels and modulates memory consolidation. However, the dynamics of these processes in behaving mice remain unexplored, as do the interactions between the distinct second messenger pathways. Here we simultaneously monitored astrocytic Ca2+ and cAMP and demonstrate that astrocytic second messengers are regulated in a temporally distinct manner. In behaving mice, we found that while an abrupt facial air puff triggered transient increases in noradrenaline release and large cytosolic astrocytic Ca2+ elevations, cAMP changes were not detectable. By contrast, repeated aversive stimuli that lead to prolonged periods of vigilance were accompanied by robust noradrenergic axonal activity and gradual sustained cAMP increases. Our findings suggest distinct astrocytic signaling pathways can integrate noradrenergic activity during vigilance states to mediate distinct functions supporting memory. Astrocytic GPCRs activate Ca2+ and cAMP signaling pathways, however, the in vivo dynamics of the two second messengers have not been fully been characterized. The authors demonstrate distinct noradrenaline-induced astrocytic Ca2+ and cAMP dynamics during startle and fear conditioning.
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49
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Kery R, Chen APF, Kirschen GW. Genetic targeting of astrocytes to combat neurodegenerative disease. Neural Regen Res 2020; 15:199-211. [PMID: 31552885 PMCID: PMC6905329 DOI: 10.4103/1673-5374.265541] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Astrocytes, glial cells that interact extensively with neurons and other support cells throughout the central nervous system, have recently come under the spotlight for their potential contribution to, or potential regenerative role in a host of neurodegenerative disorders. It is becoming increasingly clear that astrocytes, in concert with microglial cells, activate intrinsic immunological pathways in the setting of neurodegenerative injury, although the direct and indirect consequences of such activation are still largely unknown. We review the current literature on the astrocyte’s role in several neurodegenerative diseases, as well as highlighting recent advances in genetic manipulation of astrocytes that may prove critical to modulating their response to neurological injury, potentially combatting neurodegenerative damage.
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Affiliation(s)
- Rachel Kery
- Medical Scientist Training Program (MSTP), Stony Brook Medicine; Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY, USA
| | - Allen P F Chen
- Medical Scientist Training Program (MSTP), Stony Brook Medicine; Department of Neurobiology & Behavior, Stony Brook University, Stony Brook, NY, USA
| | - Gregory W Kirschen
- Medical Scientist Training Program (MSTP), Stony Brook Medicine, Stony Brook, NY, USA
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50
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Gu X, Chen W, Volkow ND, Koretsky AP, Du C, Pan Y. Synchronized Astrocytic Ca 2+ Responses in Neurovascular Coupling during Somatosensory Stimulation and for the Resting State. Cell Rep 2019; 23:3878-3890. [PMID: 29949771 PMCID: PMC7469112 DOI: 10.1016/j.celrep.2018.05.091] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 04/05/2018] [Accepted: 05/27/2018] [Indexed: 02/08/2023] Open
Abstract
The role of astrocytes in neurovascular coupling (NVC) is unclear. Here, we applied a multimodality imaging approach to concomitantly measure synchronized neuronal or astrocytic Ca2+ and hemodynamic changes in the mouse somatosensory cortex at rest and during sensory electrical stimulation. Strikingly, we found that low-frequency stimulation (0.3-1 Hz), which consistently evokes fast neuronal Ca2+ transients (6.0 ± 2.7 ms latency) that always precede vascular responses, does not always elicit astrocytic Ca2+ transients (313 ± 65 ms latency). However, the magnitude of the hemodynamic response is increased when astrocytic transients occur, suggesting a facilitatory role of astrocytes in NVC. High-frequency stimulation (5-10 Hz) consistently evokes a large, delayed astrocytic Ca2+ accumulation (3.48 ± 0.09 s latency) that is temporarily associated with vasoconstriction, suggesting a role for astrocytes in resetting NVC. At rest, neuronal, but not astrocytic, Ca2+ fluctuations correlate with hemodynamic low-frequency oscillations. Taken together, these results support a role for astrocytes in modulating, but not triggering, NVC.
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Affiliation(s)
- Xiaochun Gu
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA; Jiangsu Key Laboratory of Molecular and Functional Imaging, Key Laboratory of Developmental Genes and Human Diseases, Department of Radiology, Zhongda Hospital, Medical School, Southeast University, #87 Dingjiaqiao Road, Nanjing 210009, China
| | - Wei Chen
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Nora D Volkow
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20857, USA
| | - Alan P Koretsky
- Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA
| | - Congwu Du
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA
| | - Yingtian Pan
- Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA.
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