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Gonçalves-Ribeiro J, Savchak OK, Costa-Pinto S, Gomes JI, Rivas-Santisteban R, Lillo A, Sánchez Romero J, Sebastião AM, Navarrete M, Navarro G, Franco R, Vaz SH. Adenosine receptors are the on-and-off switch of astrocytic cannabinoid type 1 (CB1) receptor effect upon synaptic plasticity in the medial prefrontal cortex. Glia 2024; 72:1096-1116. [PMID: 38482984 DOI: 10.1002/glia.24518] [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: 08/23/2023] [Revised: 02/09/2024] [Accepted: 02/13/2024] [Indexed: 04/12/2024]
Abstract
The medial prefrontal cortex (mPFC) is involved in cognitive functions such as working memory. Astrocytic cannabinoid type 1 receptor (CB1R) induces cytosolic calcium (Ca2+) concentration changes with an impact on neuronal function. mPFC astrocytes also express adenosine A1 and A2A receptors (A1R, A2AR), being unknown the crosstalk between CB1R and adenosine receptors in these cells. We show here that a further level of regulation of astrocyte Ca2+ signaling occurs through CB1R-A2AR or CB1R-A1R heteromers that ultimately impact mPFC synaptic plasticity. CB1R-mediated Ca2+ transients increased and decreased when A1R and A2AR were activated, respectively, unveiling adenosine receptors as modulators of astrocytic CB1R. CB1R activation leads to an enhancement of long-term potentiation (LTP) in the mPFC, under the control of A1R but not of A2AR. Notably, in IP3R2KO mice, that do not show astrocytic Ca2+ level elevations, CB1R activation decreases LTP, which is not modified by A1R or A2AR. The present work suggests that CB1R has a homeostatic role on mPFC LTP, under the control of A1R, probably due to physical crosstalk between these receptors in astrocytes that ultimately alters CB1R Ca2+ signaling.
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Affiliation(s)
- Joana Gonçalves-Ribeiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Oksana K Savchak
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Sara Costa-Pinto
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Joana I Gomes
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Rafael Rivas-Santisteban
- Department of Biochemistry and Physiology, School of Pharmacy and Food Science, Universitat de Barcelona, Barcelona, Spain
- CiberNed, Network Center for Neurodegenerative Diseases, National Spanish Health Institute Carlos III, Madrid, Spain
| | - Alejandro Lillo
- Department of Biochemistry and Physiology, School of Pharmacy and Food Science, Universitat de Barcelona, Barcelona, Spain
- CiberNed, Network Center for Neurodegenerative Diseases, National Spanish Health Institute Carlos III, Madrid, Spain
| | - Javier Sánchez Romero
- Instituto Cajal, CSIC, Madrid, Spain
- PhD Program in Neuroscience, Universidad Autónoma de Madrid-Instituto Cajal, Madrid, Spain
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | | | - Gemma Navarro
- Department of Biochemistry and Physiology, School of Pharmacy and Food Science, Universitat de Barcelona, Barcelona, Spain
- CiberNed, Network Center for Neurodegenerative Diseases, National Spanish Health Institute Carlos III, Madrid, Spain
- Institut de Neurociències, Universitat de Barcelona, Barcelona, Spain
| | - Rafael Franco
- CiberNed, Network Center for Neurodegenerative Diseases, National Spanish Health Institute Carlos III, Madrid, Spain
- Molecular Neurobiology Laboratory, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
- School of Chemistry, Universitat de Barcelona, Barcelona, Spain
| | - Sandra H Vaz
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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2
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Zhang DX, Jia SY, Xiao K, Zhang MM, Yu ZF, Liu JZ, Zhang W, Zhang LM, Xing BR, Zhou TT, Li XM, Zhao XC, An P. Icariin mitigates anxiety-like behaviors induced by hemorrhagic shock and resuscitation via inhibiting of astrocytic activation. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2024; 128:155507. [PMID: 38552430 DOI: 10.1016/j.phymed.2024.155507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 01/18/2024] [Accepted: 02/28/2024] [Indexed: 05/01/2024]
Abstract
BACKGROUND Abnormal activation of astrocytes in the amygdala contributes to anxiety after hemorrhagic shock and resuscitation (HSR). Nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB)-associated epigenetic reprogramming of astrocytic activation is crucial to anxiety. A bioactive monomer derived from Epimedium icariin (ICA) has been reported to modulate NF-κB signaling and astrocytic activation. PURPOSE The present study aimed to investigate the effects of ICA on post-HSR anxiety disorders and its potential mechanism of action. METHODS We first induced HSR in mice through a bleeding and re-transfusion model and selectively inhibited and activated astrocytes in the amygdala using chemogenetics. Then, ICA (40 mg/kg) was administered by oral gavage once daily for 21 days. Behavioral, electrophysiological, and pathological changes were assessed after HSR using the light-dark transition test, elevated plus maze, recording of local field potential (LFP), and immunofluorescence assays. RESULTS Exposure to HSR reduced the duration of the light chamber and attenuated open-arm entries. Moreover, HSR exposure increased the theta oscillation power in the amygdala and upregulated NF-κB p65, H3K27ac, and H3K4me3 expression. Contrarily, chemogenetic inhibition of astrocytes significantly reversed these changes. Chemogenetic inhibition in astrocytes was simulated by ICA, but chemogenetic activation of astrocytes blocked the neuroprotective effects of ICA. CONCLUSION ICA mitigated anxiety-like behaviors induced by HSR in mice via inhibiting astrocytic activation, which is possibly associated with NF-κB-induced epigenetic reprogramming.
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Affiliation(s)
- Dong-Xue Zhang
- Department of Gerontology, Cangzhou Central Hospital, Cangzhou, China
| | - Shi-Yan Jia
- Anesthesia and Trauma Research Unit, Department of Anesthesiology, Hebei Province Cangzhou Hospital of Integrated Traditional and Western Medicine (Cangzhou No. 2 Hospital), Cangzhou, China; Hebei Province Key Laboratory of Integrated Traditional and Western Medicine in Neurological Rehabilitation, China
| | - Ke Xiao
- Department of Anesthesiology, School and Hospital of Stomatology, China Medical University, Shenyang, China
| | - Ming-Ming Zhang
- Department of Anesthesiology, School and Hospital of Stomatology, China Medical University, Shenyang, China
| | - Zhi-Fang Yu
- Anesthesia and Trauma Research Unit, Department of Anesthesiology, Hebei Province Cangzhou Hospital of Integrated Traditional and Western Medicine (Cangzhou No. 2 Hospital), Cangzhou, China
| | - Ji-Zhen Liu
- Department of Anesthesiology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Wei Zhang
- Department of Anesthesiology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Li-Min Zhang
- Anesthesia and Trauma Research Unit, Department of Anesthesiology, Hebei Province Cangzhou Hospital of Integrated Traditional and Western Medicine (Cangzhou No. 2 Hospital), Cangzhou, China
| | - Bao-Rui Xing
- Hebei Key Laboratory of Integrated Traditional and Western Medicine in Osteoarthrosis Research (Preparing)
| | - Ting-Ting Zhou
- Hebei Key Laboratory of Integrated Traditional and Western Medicine in Osteoarthrosis Research (Preparing)
| | - Xiao-Ming Li
- Hebei Key Laboratory of Integrated Traditional and Western Medicine in Osteoarthrosis Research (Preparing)
| | - Xiao-Chun Zhao
- Department of Anesthesiology, School and Hospital of Stomatology, China Medical University, Shenyang, China
| | - Ping An
- Department of Neurobiology, School of Life Science, China Medical University, Shenyang, China.
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3
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Rupprecht P, Duss SN, Becker D, Lewis CM, Bohacek J, Helmchen F. Centripetal integration of past events in hippocampal astrocytes regulated by locus coeruleus. Nat Neurosci 2024; 27:927-939. [PMID: 38570661 PMCID: PMC11089000 DOI: 10.1038/s41593-024-01612-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 02/26/2024] [Indexed: 04/05/2024]
Abstract
An essential feature of neurons is their ability to centrally integrate information from their dendrites. The activity of astrocytes, in contrast, has been described as mostly uncoordinated across cellular compartments without clear central integration. Here we report conditional integration of calcium signals in astrocytic distal processes at their soma. In the hippocampus of adult mice of both sexes, we found that global astrocytic activity, as recorded with population calcium imaging, reflected past neuronal and behavioral events on a timescale of seconds. Salient past events, indicated by pupil dilations, facilitated the propagation of calcium signals from distal processes to the soma. Centripetal propagation to the soma was reproduced by optogenetic activation of the locus coeruleus, a key regulator of arousal, and reduced by pharmacological inhibition of α1-adrenergic receptors. Together, our results suggest that astrocytes are computational units of the brain that slowly and conditionally integrate calcium signals upon behaviorally relevant events.
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Affiliation(s)
- Peter Rupprecht
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, Zürich, Switzerland.
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zürich, Switzerland.
| | - Sian N Duss
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zürich, Switzerland
- Laboratory of Molecular and Behavioral Neuroscience, Institute for Neuroscience, Department of Health Sciences and Technology, ETH Zurich, Zürich, Switzerland
| | - Denise Becker
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, Zürich, Switzerland
| | - Christopher M Lewis
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, Zürich, Switzerland
| | - Johannes Bohacek
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zürich, Switzerland
- Laboratory of Molecular and Behavioral Neuroscience, Institute for Neuroscience, Department of Health Sciences and Technology, ETH Zurich, Zürich, Switzerland
| | - Fritjof Helmchen
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, Zürich, Switzerland.
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zürich, Switzerland.
- University Research Priority Program (URPP), Adaptive Brain Circuits in Development and Learning, University of Zurich, Zürich, Switzerland.
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4
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Yu Y, Chen R, Mao K, Deng M, Li Z. The Role of Glial Cells in Synaptic Dysfunction: Insights into Alzheimer's Disease Mechanisms. Aging Dis 2024; 15:459-479. [PMID: 37548934 PMCID: PMC10917533 DOI: 10.14336/ad.2023.0718] [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: 05/12/2023] [Accepted: 07/18/2023] [Indexed: 08/08/2023] Open
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder that impacts a substantial number of individuals globally. Despite its widespread prevalence, there is currently no cure for AD. It is widely acknowledged that normal synaptic function holds a key role in memory, cognitive abilities, and the interneuronal transfer of information. As AD advances, symptoms including synaptic impairment, decreased synaptic density, and cognitive decline become increasingly noticeable. The importance of glial cells in the formation of synapses, the growth of neurons, brain maturation, and safeguarding the microenvironment of the central nervous system is well recognized. However, during AD progression, overactive glial cells can cause synaptic dysfunction, neuronal death, and abnormal neuroinflammation. Both neuroinflammation and synaptic dysfunction are present in the early stages of AD. Therefore, focusing on the changes in glia-synapse communication could provide insights into the mechanisms behind AD. In this review, we aim to provide a summary of the role of various glial cells, including microglia, astrocytes, oligodendrocytes, and oligodendrocyte precursor cells, in regulating synaptic dysfunction. This may offer a new perspective on investigating the underlying mechanisms of AD.
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Affiliation(s)
- Yang Yu
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
| | - Ran Chen
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- School of Medicine, Sun Yat-sen University, Shenzhen, China.
| | - Kaiyue Mao
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- School of Medicine, Sun Yat-sen University, Shenzhen, China.
| | - Maoyan Deng
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- School of Medicine, Sun Yat-sen University, Shenzhen, China.
| | - Zhigang Li
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
- Shenzhen Key Laboratory of Chinese Medicine Active Substance Screening and Translational Research, Shenzhen, China.
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5
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Gao Z, Wu L, Zhao X, Wei Z, Lu L, Yi M. Random fluctuations and synaptic plasticity enhance working memory activities in the neuron-astrocyte network. Cogn Neurodyn 2024; 18:503-518. [PMID: 38699624 PMCID: PMC11061073 DOI: 10.1007/s11571-023-10002-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/30/2023] [Accepted: 08/13/2023] [Indexed: 05/05/2024] Open
Abstract
Random fluctuations are inescapable feature in biological systems, but appropriate intensity of randomness can effectively facilitate information transfer and memory encoding within the nervous system. In the study, a modified spiking neuron-astrocyte network model with excitatory-inhibitory balance and synaptic plasticity is established. This model considers external input noise, and allows investigating the effects of intrinsic random fluctuations on working memory tasks. It is found that the astrocyte network, acting as a low-pass filter, reduces the noise component of the total input currents and improves the recovered images. The memory performance is enhanced by selecting appropriate intensity of random fluctuations, while excessive intensity can inhibit signal transmission of network. As the intensity of random fluctuations gradually increases, there exists a maximum value of the working memory performance. The cued recall of the network markedly decreases excessive input noise relative to test images. Meanwhile, a greater contrast effect is observed as the external input noise increases. In addition, synaptic plasticity reduces the firing rates and firing peaks of neurons, thus stabilizing the working memory activity during the test. The outcomes of this study may provide some inspirations for comprehending the role of random fluctuations in working memory mechanisms and neural information processing within the cerebral cortex.
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Affiliation(s)
- Zhuoheng Gao
- School of Mathematics and Physics, China University of Geosciences, Wuhan, 430074 China
| | - Liqing Wu
- School of Mathematics and Physics, China University of Geosciences, Wuhan, 430074 China
| | - Xin Zhao
- School of Mathematics and Physics, China University of Geosciences, Wuhan, 430074 China
| | - Zhuochao Wei
- School of Mathematics and Physics, China University of Geosciences, Wuhan, 430074 China
| | - Lulu Lu
- School of Mathematics and Physics, China University of Geosciences, Wuhan, 430074 China
| | - Ming Yi
- School of Mathematics and Physics, China University of Geosciences, Wuhan, 430074 China
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6
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Zaforas M, Miguel-Quesada C, Fernández-López E, Alonso-Calviño E, Barranco-Maresca V, Misol-Ortiz A, Aguilar J, Rosa JM. Protocol for stimulating specific rodent limb receptive fields while recording in vivo somatosensory-evoked activity. STAR Protoc 2024; 5:102972. [PMID: 38502685 PMCID: PMC10960094 DOI: 10.1016/j.xpro.2024.102972] [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: 01/02/2024] [Revised: 02/06/2024] [Accepted: 03/05/2024] [Indexed: 03/21/2024] Open
Abstract
Studies on sensory information processing typically focus on whisker-related tactile information, overlooking the question of how sensory inputs from other body areas are processed at cortical levels. Here, we present a protocol for stimulating specific rodent limb receptive fields while recording in vivo somatosensory-evoked activity. We describe steps for localizing cortical-hindlimb coordinates using acute peripheral stimulation, electrode placement, and the application of electrical stimulation. This protocol overcomes the challenge of inducing a reproducible and consistent stimulation of specific limbs. For complete details on the use and execution of this protocol, please refer to Miguel-Quesada et al.1.
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Affiliation(s)
- Marta Zaforas
- Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos. SESCAM, 45071 Toledo, Spain; Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain.
| | - Claudia Miguel-Quesada
- Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos. SESCAM, 45071 Toledo, Spain; Neuronal Circuits and Behaviour Group, Hospital Nacional de Parapléjicos, 45071 Toledo, Spain
| | - Elena Fernández-López
- Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos. SESCAM, 45071 Toledo, Spain; Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain
| | - Elena Alonso-Calviño
- Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos. SESCAM, 45071 Toledo, Spain; Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain
| | - Verónica Barranco-Maresca
- Neuronal Circuits and Behaviour Group, Hospital Nacional de Parapléjicos, 45071 Toledo, Spain; Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain
| | - Andrea Misol-Ortiz
- Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos. SESCAM, 45071 Toledo, Spain; Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain
| | - Juan Aguilar
- Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos. SESCAM, 45071 Toledo, Spain; Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain
| | - Juliana M Rosa
- Neuronal Circuits and Behaviour Group, Hospital Nacional de Parapléjicos, 45071 Toledo, Spain; Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain.
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7
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Chen X, Tang SJ. Neural Circuitry Polarization in the Spinal Dorsal Horn (SDH): A Novel Form of Dysregulated Circuitry Plasticity during Pain Pathogenesis. Cells 2024; 13:398. [PMID: 38474361 PMCID: PMC10930392 DOI: 10.3390/cells13050398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024] Open
Abstract
Pathological pain emerges from nociceptive system dysfunction, resulting in heightened pain circuit activity. Various forms of circuitry plasticity, such as central sensitization, synaptic plasticity, homeostatic plasticity, and excitation/inhibition balance, contribute to the malfunction of neural circuits during pain pathogenesis. Recently, a new form of plasticity in the spinal dorsal horn (SDH), named neural circuit polarization (NCP), was discovered in pain models induced by HIV-1 gp120 and chronic morphine administration. NCP manifests as an increase in excitatory postsynaptic currents (EPSCs) in excitatory neurons and a decrease in EPSCs in inhibitory neurons, presumably facilitating hyperactivation of pain circuits. The expression of NCP is associated with astrogliosis. Ablation of reactive astrocytes or suppression of astrogliosis blocks NCP and, concomitantly, the development of gp120- or morphine-induced pain. In this review, we aim to compare and integrate NCP with other forms of plasticity in pain circuits to improve the understanding of the pathogenic contribution of NCP and its cooperation with other forms of circuitry plasticity during the development of pathological pain.
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Affiliation(s)
| | - Shao-Jun Tang
- Stony Brook University Pain and Anesthesia Research Center (SPARC), Department of Anesthesiology, Stony Brook University, Stony Brook, NY 11794, USA;
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8
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Escalada P, Ezkurdia A, Ramírez MJ, Solas M. Essential Role of Astrocytes in Learning and Memory. Int J Mol Sci 2024; 25:1899. [PMID: 38339177 PMCID: PMC10856373 DOI: 10.3390/ijms25031899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/12/2024] Open
Abstract
One of the most biologically relevant functions of astrocytes within the CNS is the regulation of synaptic transmission, i.e., the physiological basis for information transmission between neurons. Changes in the strength of synaptic connections are indeed thought to be the cellular basis of learning and memory. Importantly, astrocytes have been demonstrated to tightly regulate these processes via the release of several gliotransmitters linked to astrocytic calcium activity as well as astrocyte-neuron metabolic coupling. Therefore, astrocytes seem to be integrators of and actors upon learning- and memory-relevant information. In this review, we focus on the role of astrocytes in learning and memory processes. We delineate the recognized inputs and outputs of astrocytes and explore the influence of manipulating astrocytes on behaviour across diverse learning paradigms. We conclude that astrocytes influence learning and memory in various manners. Appropriate astrocytic Ca2+ dynamics are being increasingly identified as central contributors to memory formation and retrieval. In addition, astrocytes regulate brain rhythms essential for cognition, and astrocyte-neuron metabolic cooperation is required for memory consolidation.
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Affiliation(s)
- Paula Escalada
- Department of Pharmaceutical Sciences, University of Navarra, 31008 Pamplona, Spain; (P.E.); (A.E.); (M.J.R.)
| | - Amaia Ezkurdia
- Department of Pharmaceutical Sciences, University of Navarra, 31008 Pamplona, Spain; (P.E.); (A.E.); (M.J.R.)
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
| | - María Javier Ramírez
- Department of Pharmaceutical Sciences, University of Navarra, 31008 Pamplona, Spain; (P.E.); (A.E.); (M.J.R.)
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
| | - Maite Solas
- Department of Pharmaceutical Sciences, University of Navarra, 31008 Pamplona, Spain; (P.E.); (A.E.); (M.J.R.)
- IdiSNA, Navarra Institute for Health Research, 31008 Pamplona, Spain
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9
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Del Franco AP, Newman EA. Astrocyte β-Adrenergic Receptor Activity Regulates NMDA Receptor Signaling of Medial Prefrontal Cortex Pyramidal Neurons. J Neurosci 2024; 44:e0990232023. [PMID: 37989594 PMCID: PMC10860478 DOI: 10.1523/jneurosci.0990-23.2023] [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: 05/29/2023] [Revised: 10/23/2023] [Accepted: 11/13/2023] [Indexed: 11/23/2023] Open
Abstract
Glutamate spillover from the synapse is tightly regulated by astrocytes, limiting the activation of extrasynaptically located NMDA receptors (NMDAR). The processes of astrocytes are dynamic and can modulate synaptic physiology. Though norepinephrine (NE) and β-adrenergic receptor (β-AR) activity can modify astrocyte volume, this has yet to be confirmed outside of sensory cortical areas, nor has the effect of noradrenergic signaling on glutamate spillover and neuronal NMDAR activity been explored. We monitored changes to astrocyte process volume in response to noradrenergic agonists in the medial prefrontal cortex of male and female mice. Both NE and the β-AR agonist isoproterenol (ISO) increased process volume by ∼20%, significantly higher than changes seen when astrocytes had G-protein signaling blocked by GDPβS. We measured the effect of β-AR signaling on evoked NMDAR currents. While ISO did not affect single stimulus excitatory currents of Layer 5 pyramidal neurons, ISO reduced NMDAR currents evoked by 10 stimuli at 50 Hz, which elicits glutamate spillover, by 18%. After isolating extrasynaptic NMDARs by blocking synaptic NMDARs with the activity-dependent NMDAR blocker MK-801, ISO similarly reduced extrasynaptic NMDAR currents in response to 10 stimuli by 18%. Finally, blocking β-AR signaling in the astrocyte network by loading them with GDPβS reversed the ISO effect on 10 stimuli-evoked NMDAR currents. These results demonstrate that astrocyte β-AR activity reduces extrasynaptic NMDAR recruitment, suggesting that glutamate spillover is reduced.
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Affiliation(s)
- Armani P Del Franco
- Department of Neuroscience, University of Minnesota, Minneapolis 55455, Minnesota
| | - Eric A Newman
- Department of Neuroscience, University of Minnesota, Minneapolis 55455, Minnesota
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10
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Naghieh P, Delavar A, Amiri M, Peremans H. Astrocyte's self-repairing characteristics improve working memory in spiking neuronal networks. iScience 2023; 26:108241. [PMID: 38047076 PMCID: PMC10692671 DOI: 10.1016/j.isci.2023.108241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 08/23/2023] [Accepted: 10/15/2023] [Indexed: 12/05/2023] Open
Abstract
Astrocytes play a significant role in the working memory (WM) mechanism, yet their contribution to spiking neuron-astrocyte networks (SNAN) is underexplored. This study proposes a non-probabilistic SNAN incorporating a self-repairing (SR) mechanism through endocannabinoid pathways to facilitate WM function. Four experiments were conducted with different damaging patterns, replicating close-to-realistic synaptic impairments. Simulation results suggest that the SR process enhances WM performance by improving the consistency of neuronal firing. Moreover, the intercellular astrocytic [Ca]2+ transmission via gap junctions improves WM and SR processes. With increasing damage, WM and SR activities initially fail for non-matched samples and then for smaller and minimally overlapping matched samples. Simulation results also indicate that the inclusion of the SR mechanism in both random and continuous forms of damage improves the resilience of the WM by approximately 20%. This study highlights the importance of astrocytes in synaptically impaired networks.
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Affiliation(s)
- Pedram Naghieh
- Medical Technology Research Center, Institute of Health Technology, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Abolfazl Delavar
- Medical Technology Research Center, Institute of Health Technology, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mahmood Amiri
- Medical Technology Research Center, Institute of Health Technology, Kermanshah University of Medical Sciences, Kermanshah, Iran
- Department of Engineering Management, University of Antwerp, Antwerp, Belgium
| | - Herbert Peremans
- Department of Engineering Management, University of Antwerp, Antwerp, Belgium
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11
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Hastings N, Yu Y, Huang B, Middya S, Inaoka M, Erkamp NA, Mason RJ, Carnicer‐Lombarte A, Rahman S, Knowles TPJ, Bance M, Malliaras GG, Kotter MRN. Electrophysiological In Vitro Study of Long-Range Signal Transmission by Astrocytic Networks. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301756. [PMID: 37485646 PMCID: PMC10582426 DOI: 10.1002/advs.202301756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/09/2023] [Indexed: 07/25/2023]
Abstract
Astrocytes are diverse brain cells that form large networks communicating via gap junctions and chemical transmitters. Despite recent advances, the functions of astrocytic networks in information processing in the brain are not fully understood. In culture, brain slices, and in vivo, astrocytes, and neurons grow in tight association, making it challenging to establish whether signals that spread within astrocytic networks communicate with neuronal groups at distant sites, or whether astrocytes solely respond to their local environments. A multi-electrode array (MEA)-based device called AstroMEA is designed to separate neuronal and astrocytic networks, thus allowing to study the transfer of chemical and/or electrical signals transmitted via astrocytic networks capable of changing neuronal electrical behavior. AstroMEA demonstrates that cortical astrocytic networks can induce a significant upregulation in the firing frequency of neurons in response to a theta-burst charge-balanced biphasic current stimulation (5 pulses of 100 Hz × 10 with 200 ms intervals, 2 s total duration) of a separate neuronal-astrocytic group in the absence of direct neuronal contact. This result corroborates the view of astrocytic networks as a parallel mechanism of signal transmission in the brain that is separate from the neuronal connectome. Translationally, it highlights the importance of astrocytic network protection as a treatment target.
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Affiliation(s)
- Nataly Hastings
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Yi‐Lin Yu
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Department of Neurological SurgeryTri‐Service General HospitalNational Defence Medical CentreTaipei, Neihu District11490Taiwan
| | - Botian Huang
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | - Sagnik Middya
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Misaki Inaoka
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Nadia A. Erkamp
- Yusuf Hamied Department of ChemistryCentre for Misfolding DiseasesUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Roger J. Mason
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | | | - Saifur Rahman
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
| | - Tuomas P. J. Knowles
- Yusuf Hamied Department of ChemistryCentre for Misfolding DiseasesUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
- Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJ J Thomson AveCambridgeCB3 0HEUK
| | - Manohar Bance
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | - George G. Malliaras
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Mark R. N. Kotter
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
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12
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Roqué PJ, Barria A, Zhang X, Hashimoto JG, Costa LG, Guizzetti M. Synaptogenesis by Cholinergic Stimulation of Astrocytes. Neurochem Res 2023; 48:3212-3227. [PMID: 37402036 PMCID: PMC10493036 DOI: 10.1007/s11064-023-03979-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 05/31/2023] [Accepted: 06/27/2023] [Indexed: 07/05/2023]
Abstract
Astrocytes release numerous factors known to contribute to the process of synaptogenesis, yet knowledge about the signals that control their release is limited. We hypothesized that neuron-derived signals stimulate astrocytes, which respond to neurons through the modulation of astrocyte-released synaptogenic factors. Here we investigate the effect of cholinergic stimulation of astrocytes on synaptogenesis in co-cultured neurons. Using a culture system where primary rat astrocytes and primary rat neurons are first grown separately allowed us to independently manipulate astrocyte cholinergic signaling. Subsequent co-culture of pre-stimulated astrocytes with naïve neurons enabled us to assess how prior stimulation of astrocyte acetylcholine receptors uniquely modulates neuronal synapse formation. Pre-treatment of astrocytes with the acetylcholine receptor agonist carbachol increased the expression of synaptic proteins, the number of pre- and postsynaptic puncta, and the number of functional synapses in hippocampal neurons after 24 h in co-culture. Astrocyte secretion of the synaptogenic protein thrombospondin-1 increased after cholinergic stimulation and inhibition of the receptor for thrombospondins prevented the increase in neuronal synaptic structures. Thus, we identified a novel mechanism of neuron-astrocyte-neuron communication, where neuronal release of acetylcholine stimulates astrocytes to release synaptogenic proteins leading to increased synaptogenesis in neurons. This study provides new insights into the role of neurotransmitter receptors in developing astrocytes and into our understanding of the modulation of astrocyte-induced synaptogenesis.
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Affiliation(s)
- Pamela J Roqué
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Andrés Barria
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Xiaolu Zhang
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, USA
- VA Portland Health Care System, Portland, OR, USA
| | - Joel G Hashimoto
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, USA
- VA Portland Health Care System, Portland, OR, USA
| | - Lucio G Costa
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
- Department of Medicine & Surgery, University of Parma, Parma, Italy
| | - Marina Guizzetti
- Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR, USA.
- VA Portland Health Care System, Portland, OR, USA.
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13
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Miguel-Quesada C, Zaforas M, Herrera-Pérez S, Lines J, Fernández-López E, Alonso-Calviño E, Ardaya M, Soria FN, Araque A, Aguilar J, Rosa JM. Astrocytes adjust the dynamic range of cortical network activity to control modality-specific sensory information processing. Cell Rep 2023; 42:112950. [PMID: 37543946 DOI: 10.1016/j.celrep.2023.112950] [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: 10/19/2022] [Revised: 03/21/2023] [Accepted: 07/23/2023] [Indexed: 08/08/2023] Open
Abstract
Cortical neuron-astrocyte communication in response to peripheral sensory stimulation occurs in a topographic-, frequency-, and intensity-dependent manner. However, the contribution of this functional interaction to the processing of sensory inputs and consequent behavior remains unclear. We investigate the role of astrocytes in sensory information processing at circuit and behavioral levels by monitoring and manipulating astrocytic activity in vivo. We show that astrocytes control the dynamic range of the cortical network activity, optimizing its responsiveness to incoming sensory inputs. The astrocytic modulation of sensory processing contributes to setting the detection threshold for tactile and thermal behavior responses. The mechanism of such astrocytic control is mediated through modulation of inhibitory transmission to adjust the gain and sensitivity of responding networks. These results uncover a role for astrocytes in maintaining the cortical network activity in an optimal range to control behavior associated with specific sensory modalities.
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Affiliation(s)
- Claudia Miguel-Quesada
- Neuronal Circuits and Behaviour Group, Hospital Nacional de Parapléjicos, Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain; Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos, Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain
| | - Marta Zaforas
- Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos, Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain
| | - Salvador Herrera-Pérez
- Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos, Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain
| | - Justin Lines
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Elena Fernández-López
- Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos, Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain
| | - Elena Alonso-Calviño
- Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos, Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain
| | - Maria Ardaya
- Donostia International Physics Center (DIPC), 20018 San Sebastian, Spain; Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain
| | - Federico N Soria
- Achucarro Basque Center for Neuroscience, 48940 Leioa, Spain; Ikerbasque, Basque Foundation for Science, 48009 Bilbao, Spain; Centro de Investigación Biomédica en Red Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Juan Aguilar
- Experimental Neurophysiology Group, Hospital Nacional de Parapléjicos, Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain.
| | - Juliana M Rosa
- Neuronal Circuits and Behaviour Group, Hospital Nacional de Parapléjicos, Instituto de Investigación Sanitaria de Castilla-La Mancha (IDISCAM), 45071 Toledo, Spain.
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14
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Gebicke-Haerter PJ. The computational power of the human brain. Front Cell Neurosci 2023; 17:1220030. [PMID: 37608987 PMCID: PMC10441807 DOI: 10.3389/fncel.2023.1220030] [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: 05/19/2023] [Accepted: 07/05/2023] [Indexed: 08/24/2023] Open
Abstract
At the end of the 20th century, analog systems in computer science have been widely replaced by digital systems due to their higher computing power. Nevertheless, the question keeps being intriguing until now: is the brain analog or digital? Initially, the latter has been favored, considering it as a Turing machine that works like a digital computer. However, more recently, digital and analog processes have been combined to implant human behavior in robots, endowing them with artificial intelligence (AI). Therefore, we think it is timely to compare mathematical models with the biology of computation in the brain. To this end, digital and analog processes clearly identified in cellular and molecular interactions in the Central Nervous System are highlighted. But above that, we try to pinpoint reasons distinguishing in silico computation from salient features of biological computation. First, genuinely analog information processing has been observed in electrical synapses and through gap junctions, the latter both in neurons and astrocytes. Apparently opposed to that, neuronal action potentials (APs) or spikes represent clearly digital events, like the yes/no or 1/0 of a Turing machine. However, spikes are rarely uniform, but can vary in amplitude and widths, which has significant, differential effects on transmitter release at the presynaptic terminal, where notwithstanding the quantal (vesicular) release itself is digital. Conversely, at the dendritic site of the postsynaptic neuron, there are numerous analog events of computation. Moreover, synaptic transmission of information is not only neuronal, but heavily influenced by astrocytes tightly ensheathing the majority of synapses in brain (tripartite synapse). At least at this point, LTP and LTD modifying synaptic plasticity and believed to induce short and long-term memory processes including consolidation (equivalent to RAM and ROM in electronic devices) have to be discussed. The present knowledge of how the brain stores and retrieves memories includes a variety of options (e.g., neuronal network oscillations, engram cells, astrocytic syncytium). Also epigenetic features play crucial roles in memory formation and its consolidation, which necessarily guides to molecular events like gene transcription and translation. In conclusion, brain computation is not only digital or analog, or a combination of both, but encompasses features in parallel, and of higher orders of complexity.
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Affiliation(s)
- Peter J. Gebicke-Haerter
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine, University of Heidelberg, Mannheim, Germany
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15
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Pereira MJ, Ayana R, Holt MG, Arckens L. Chemogenetic manipulation of astrocyte activity at the synapse- a gateway to manage brain disease. Front Cell Dev Biol 2023; 11:1193130. [PMID: 37534103 PMCID: PMC10393042 DOI: 10.3389/fcell.2023.1193130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 06/14/2023] [Indexed: 08/04/2023] Open
Abstract
Astrocytes are the major glial cell type in the central nervous system (CNS). Initially regarded as supportive cells, it is now recognized that this highly heterogeneous cell population is an indispensable modulator of brain development and function. Astrocytes secrete neuroactive molecules that regulate synapse formation and maturation. They also express hundreds of G protein-coupled receptors (GPCRs) that, once activated by neurotransmitters, trigger intracellular signalling pathways that can trigger the release of gliotransmitters which, in turn, modulate synaptic transmission and neuroplasticity. Considering this, it is not surprising that astrocytic dysfunction, leading to synaptic impairment, is consistently described as a factor in brain diseases, whether they emerge early or late in life due to genetic or environmental factors. Here, we provide an overview of the literature showing that activation of genetically engineered GPCRs, known as Designer Receptors Exclusively Activated by Designer Drugs (DREADDs), to specifically modulate astrocyte activity partially mimics endogenous signalling pathways in astrocytes and improves neuronal function and behavior in normal animals and disease models. Therefore, we propose that expressing these genetically engineered GPCRs in astrocytes could be a promising strategy to explore (new) signalling pathways which can be used to manage brain disorders. The precise molecular, functional and behavioral effects of this type of manipulation, however, differ depending on the DREADD receptor used, targeted brain region and timing of the intervention, between healthy and disease conditions. This is likely a reflection of regional and disease/disease progression-associated astrocyte heterogeneity. Therefore, a thorough investigation of the effects of such astrocyte manipulation(s) must be conducted considering the specific cellular and molecular environment characteristic of each disease and disease stage before this has therapeutic applicability.
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Affiliation(s)
- Maria João Pereira
- Department of Biology, Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, Leuven, Belgium
| | - Rajagopal Ayana
- Department of Biology, Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, Leuven, Belgium
| | - Matthew G. Holt
- Instituto de Investigação e Inovação em Saúde (i3S), Laboratory of Synapse Biology, Universidade do Porto, Porto, Portugal
| | - Lutgarde Arckens
- Department of Biology, Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, Leuven, Belgium
- KU Leuven Brain Institute, Leuven, Belgium
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16
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Cunha-Garcia D, Monteiro-Fernandes D, Correia JS, Neves-Carvalho A, Vilaça-Ferreira AC, Guerra-Gomes S, Viana JF, Oliveira JF, Teixeira-Castro A, Maciel P, Duarte-Silva S. Genetic Ablation of Inositol 1,4,5-Trisphosphate Receptor Type 2 (IP 3R2) Fails to Modify Disease Progression in a Mouse Model of Spinocerebellar Ataxia Type 3. Int J Mol Sci 2023; 24:10606. [PMID: 37445783 PMCID: PMC10341520 DOI: 10.3390/ijms241310606] [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: 05/15/2023] [Revised: 06/07/2023] [Accepted: 06/16/2023] [Indexed: 07/15/2023] Open
Abstract
Spinocerebellar ataxia type 3 (SCA3) is a rare neurodegenerative disease caused by an abnormal polyglutamine expansion within the ataxin-3 protein (ATXN3). This leads to neurodegeneration of specific brain and spinal cord regions, resulting in a progressive loss of motor function. Despite neuronal death, non-neuronal cells, including astrocytes, are also involved in SCA3 pathogenesis. Astrogliosis is a common pathological feature in SCA3 patients and animal models of the disease. However, the contribution of astrocytes to SCA3 is not clearly defined. Inositol 1,4,5-trisphosphate receptor type 2 (IP3R2) is the predominant IP3R in mediating astrocyte somatic calcium signals, and genetically ablation of IP3R2 has been widely used to study astrocyte function. Here, we aimed to investigate the relevance of IP3R2 in the onset and progression of SCA3. For this, we tested whether IP3R2 depletion and the consecutive suppression of global astrocytic calcium signalling would lead to marked changes in the behavioral phenotype of a SCA3 mouse model, the CMVMJD135 transgenic line. This was achieved by crossing IP3R2 null mice with the CMVMJD135 mouse model and performing a longitudinal behavioral characterization of these mice using well-established motor-related function tests. Our results demonstrate that IP3R2 deletion in astrocytes does not modify SCA3 progression.
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Affiliation(s)
- Daniela Cunha-Garcia
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (D.C.-G.); (D.M.-F.); (J.S.C.); (A.N.-C.); (A.C.V.-F.); (S.G.-G.); (J.F.V.); (J.F.O.); (A.T.-C.)
- ICVS/3B’s—PT Government Associate Laboratory, 4710-057 Braga/4805-017 Guimarães, Portugal
| | - Daniela Monteiro-Fernandes
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (D.C.-G.); (D.M.-F.); (J.S.C.); (A.N.-C.); (A.C.V.-F.); (S.G.-G.); (J.F.V.); (J.F.O.); (A.T.-C.)
- ICVS/3B’s—PT Government Associate Laboratory, 4710-057 Braga/4805-017 Guimarães, Portugal
| | - Joana Sofia Correia
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (D.C.-G.); (D.M.-F.); (J.S.C.); (A.N.-C.); (A.C.V.-F.); (S.G.-G.); (J.F.V.); (J.F.O.); (A.T.-C.)
- ICVS/3B’s—PT Government Associate Laboratory, 4710-057 Braga/4805-017 Guimarães, Portugal
| | - Andreia Neves-Carvalho
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (D.C.-G.); (D.M.-F.); (J.S.C.); (A.N.-C.); (A.C.V.-F.); (S.G.-G.); (J.F.V.); (J.F.O.); (A.T.-C.)
- ICVS/3B’s—PT Government Associate Laboratory, 4710-057 Braga/4805-017 Guimarães, Portugal
| | - Ana Catarina Vilaça-Ferreira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (D.C.-G.); (D.M.-F.); (J.S.C.); (A.N.-C.); (A.C.V.-F.); (S.G.-G.); (J.F.V.); (J.F.O.); (A.T.-C.)
- ICVS/3B’s—PT Government Associate Laboratory, 4710-057 Braga/4805-017 Guimarães, Portugal
| | - Sónia Guerra-Gomes
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (D.C.-G.); (D.M.-F.); (J.S.C.); (A.N.-C.); (A.C.V.-F.); (S.G.-G.); (J.F.V.); (J.F.O.); (A.T.-C.)
- ICVS/3B’s—PT Government Associate Laboratory, 4710-057 Braga/4805-017 Guimarães, Portugal
| | - João Filipe Viana
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (D.C.-G.); (D.M.-F.); (J.S.C.); (A.N.-C.); (A.C.V.-F.); (S.G.-G.); (J.F.V.); (J.F.O.); (A.T.-C.)
- ICVS/3B’s—PT Government Associate Laboratory, 4710-057 Braga/4805-017 Guimarães, Portugal
| | - João Filipe Oliveira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (D.C.-G.); (D.M.-F.); (J.S.C.); (A.N.-C.); (A.C.V.-F.); (S.G.-G.); (J.F.V.); (J.F.O.); (A.T.-C.)
- ICVS/3B’s—PT Government Associate Laboratory, 4710-057 Braga/4805-017 Guimarães, Portugal
- IPCA-EST-2Ai, Polytechnic Institute of Cávado and Ave, Applied Artificial Intelligence Laboratory, Campus of IPCA, 4750-810 Barcelos, Portugal
| | - Andreia Teixeira-Castro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (D.C.-G.); (D.M.-F.); (J.S.C.); (A.N.-C.); (A.C.V.-F.); (S.G.-G.); (J.F.V.); (J.F.O.); (A.T.-C.)
- ICVS/3B’s—PT Government Associate Laboratory, 4710-057 Braga/4805-017 Guimarães, Portugal
| | - Patrícia Maciel
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (D.C.-G.); (D.M.-F.); (J.S.C.); (A.N.-C.); (A.C.V.-F.); (S.G.-G.); (J.F.V.); (J.F.O.); (A.T.-C.)
- ICVS/3B’s—PT Government Associate Laboratory, 4710-057 Braga/4805-017 Guimarães, Portugal
| | - Sara Duarte-Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; (D.C.-G.); (D.M.-F.); (J.S.C.); (A.N.-C.); (A.C.V.-F.); (S.G.-G.); (J.F.V.); (J.F.O.); (A.T.-C.)
- ICVS/3B’s—PT Government Associate Laboratory, 4710-057 Braga/4805-017 Guimarães, Portugal
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17
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Ma W, Si T, Wang Z, Wen P, Zhu Z, Liu Q, Wang J, Xu F, Li Q. Astrocytic α4-containing nAChR signaling in the hippocampus governs the formation of temporal association memory. Cell Rep 2023; 42:112674. [PMID: 37352098 DOI: 10.1016/j.celrep.2023.112674] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 03/24/2023] [Accepted: 06/06/2023] [Indexed: 06/25/2023] Open
Abstract
Everyday episodic memories involve linking together related events that are temporally separated. However, the mechanisms of forming this temporal association have remained unclear. Here, using astrocyte-specific manipulations, we show that potentiating astrocyte Ca2+ signaling in the hippocampal cornu ammonis 1 (CA1) enhances the strength of such temporal association, in parallel with long-term potentiation (LTP) enhancement of temporoammonic pathway to CA1, whereas attenuation of astrocyte Ca2+ signaling has the opposite effect. Moreover, we identify that these effects are mediated by astrocytic α4 subunit-containing nicotinic acetylcholine receptors (α4-nAChRs) via mechanisms involving NMDAR co-agonist supply. Finally, astrocytic α4-nAChRs underlie the cognitive enhancer nicotine's physiological effects. Together, these findings highlight the importance of astrocyte Ca2+ signaling in cognitive behavior and reveal a mechanism in governing the temporal association of episodic memory formation that operates through α4-nAChRs on hippocampal astrocytes.
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Affiliation(s)
- Wenyu Ma
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tengxiao Si
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zan Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pengjie Wen
- Shenzhen Key Laboratory of Viral Vectors for Biomedicine, NMPA Key Laboratory for Research and Evaluation of Viral Vector Technology in Cell and Gene Therapy Medicinal Products, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Zhenxiang Zhu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; Shenzhen Key Laboratory of Viral Vectors for Biomedicine, NMPA Key Laboratory for Research and Evaluation of Viral Vector Technology in Cell and Gene Therapy Medicinal Products, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qing Liu
- Shenzhen Key Laboratory of Viral Vectors for Biomedicine, NMPA Key Laboratory for Research and Evaluation of Viral Vector Technology in Cell and Gene Therapy Medicinal Products, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Wang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fuqiang Xu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; Shenzhen Key Laboratory of Viral Vectors for Biomedicine, NMPA Key Laboratory for Research and Evaluation of Viral Vector Technology in Cell and Gene Therapy Medicinal Products, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Qin Li
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Key Laboratory of Magnetic Resonance in Biological Systems, Wuhan Center for Magnetic Resonance, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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18
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Andrade-Talavera Y, Fisahn A, Rodríguez-Moreno A. Timing to be precise? An overview of spike timing-dependent plasticity, brain rhythmicity, and glial cells interplay within neuronal circuits. Mol Psychiatry 2023; 28:2177-2188. [PMID: 36991134 PMCID: PMC10611582 DOI: 10.1038/s41380-023-02027-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 03/31/2023]
Abstract
In the mammalian brain information processing and storage rely on the complex coding and decoding events performed by neuronal networks. These actions are based on the computational ability of neurons and their functional engagement in neuronal assemblies where precise timing of action potential firing is crucial. Neuronal circuits manage a myriad of spatially and temporally overlapping inputs to compute specific outputs that are proposed to underly memory traces formation, sensory perception, and cognitive behaviors. Spike-timing-dependent plasticity (STDP) and electrical brain rhythms are suggested to underlie such functions while the physiological evidence of assembly structures and mechanisms driving both processes continues to be scarce. Here, we review foundational and current evidence on timing precision and cooperative neuronal electrical activity driving STDP and brain rhythms, their interactions, and the emerging role of glial cells in such processes. We also provide an overview of their cognitive correlates and discuss current limitations and controversies, future perspectives on experimental approaches, and their application in humans.
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Affiliation(s)
- Yuniesky Andrade-Talavera
- Laboratory of Cellular Neuroscience and Plasticity, Department of Physiology, Anatomy and Cell Biology, Universidad Pablo de Olavide, ES-41013, Seville, Spain.
| | - André Fisahn
- Department of Biosciences and Nutrition and Department of Women's and Children's Health, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Antonio Rodríguez-Moreno
- Laboratory of Cellular Neuroscience and Plasticity, Department of Physiology, Anatomy and Cell Biology, Universidad Pablo de Olavide, ES-41013, Seville, Spain.
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19
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Gau YTA, Hsu E, Cha J, Pak RW, Looger LL, Kang JU, Bergles DE. Multicore fiber optic imaging reveals that astrocyte calcium activity in the cerebral cortex is modulated by internal motivational state. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.18.541390. [PMID: 37292710 PMCID: PMC10245653 DOI: 10.1101/2023.05.18.541390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Astrocytes are a direct target of neuromodulators and can influence neuronal activity on broad spatial and temporal scales through their close proximity to synapses. However, our knowledge about how astrocytes are functionally recruited during different animal behaviors and their diverse effects on the CNS remains limited. To enable measurement of astrocyte activity patterns in vivo during normative behaviors, we developed a high-resolution, long working distance, multi-core fiber optic imaging platform that allows visualization of cortical astrocyte calcium transients through a cranial window in freely moving mice. Using this platform, we defined the spatiotemporal dynamics of astrocytes during diverse behaviors, ranging from circadian fluctuations to novelty exploration, showing that astrocyte activity patterns are more variable and less synchronous than apparent in head-immobilized imaging conditions. Although the activity of astrocytes in visual cortex was highly synchronized during quiescence to arousal transitions, individual astrocytes often exhibited distinct thresholds and activity patterns during explorative behaviors, in accordance with their molecular diversity, allowing temporal sequencing across the astrocyte network. Imaging astrocyte activity during self-initiated behaviors revealed that noradrenergic and cholinergic systems act synergistically to recruit astrocytes during state transitions associated with arousal and attention, which was profoundly modulated by internal state. The distinct activity patterns exhibited by astrocytes in the cerebral cortex may provide a means to vary their neuromodulatory influence in response to different behaviors and internal states.
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Affiliation(s)
- Yung-Tian A. Gau
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, United States
| | - Eric Hsu
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, United States
| | - Jaepyeong Cha
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, United States
| | - Rebecca W. Pak
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, United States
| | - Loren L. Looger
- Howard Hughes Medical Institute, Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, United States
| | - Jin U. Kang
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, United States
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, United States
| | - Dwight E. Bergles
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, United States
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, United States
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20
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Fontana IC, Kumar A, Nordberg A. The role of astrocytic α7 nicotinic acetylcholine receptors in Alzheimer disease. Nat Rev Neurol 2023; 19:278-288. [PMID: 36977843 DOI: 10.1038/s41582-023-00792-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2023] [Indexed: 03/30/2023]
Abstract
The ongoing search for therapeutic interventions in Alzheimer disease (AD) has highlighted the complexity of this condition and the need for additional biomarkers, beyond amyloid-β (Aβ) and tau, to improve clinical assessment. Astrocytes are brain cells that control metabolic and redox homeostasis, among other functions, and are emerging as an important focus of AD research owing to their swift response to brain pathology in the initial stages of the disease. Reactive astrogliosis - the morphological, molecular and functional transformation of astrocytes during disease - has been implicated in AD progression, and the definition of new astrocytic biomarkers could help to deepen our understanding of reactive astrogliosis along the AD continuum. As we highlight in this Review, one promising biomarker candidate is the astrocytic α7 nicotinic acetylcholine receptor (α7nAChR), upregulation of which correlates with Aβ pathology in the brain of individuals with AD. We revisit the past two decades of research into astrocytic α7nAChRs to shed light on their roles in the context of AD pathology and biomarkers. We discuss the involvement of astrocytic α7nAChRs in the instigation and potentiation of early Aβ pathology and explore their potential as a target for future reactive astrocyte-based therapeutics and imaging biomarkers in AD.
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Affiliation(s)
- Igor C Fontana
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Amit Kumar
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Agneta Nordberg
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.
- Theme Inflammation and Aging, Karolinska University Hospital, Stockholm, Sweden.
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21
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Baraibar AM, Belisle L, Marsicano G, Matute C, Mato S, Araque A, Kofuji P. Spatial organization of neuron-astrocyte interactions in the somatosensory cortex. Cereb Cortex 2023; 33:4498-4511. [PMID: 36124663 PMCID: PMC10110431 DOI: 10.1093/cercor/bhac357] [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] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/15/2022] Open
Abstract
Microcircuits in the neocortex are functionally organized along layers and columns, which are the fundamental modules of cortical information processing. While the function of cortical microcircuits has focused on neuronal elements, much less is known about the functional organization of astrocytes and their bidirectional interaction with neurons. Here, we show that Cannabinoid type 1 receptor (CB1R)-mediated astrocyte activation by neuron-released endocannabinoids elevate astrocyte Ca2+ levels, stimulate ATP/adenosine release as gliotransmitters, and transiently depress synaptic transmission in layer 5 pyramidal neurons at relatively distant synapses (˃20 μm) from the stimulated neuron. This astrocyte-mediated heteroneuronal synaptic depression occurred between pyramidal neurons within a cortical column and was absent in neurons belonging to adjacent cortical columns. Moreover, this form of heteroneuronal synaptic depression occurs between neurons located in particular layers, following a specific connectivity pattern that depends on a layer-specific neuron-to-astrocyte signaling. These results unravel the existence of astrocyte-mediated nonsynaptic communication between cortical neurons and that this communication is column- and layer-specific, which adds further complexity to the intercellular signaling processes in the neocortex.
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Affiliation(s)
- Andrés M Baraibar
- Department of Neuroscience, University of Minnesota. Minneapolis, MN, USA
- Department of Neurosciences, University of the Basque Country UPV/EHU, Leioa, Spain
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Biocruces Bizkaia, Baracaldo, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Lindsey Belisle
- Department of Neuroscience, University of Minnesota. Minneapolis, MN, USA
| | - Giovanni Marsicano
- INSERM, U862 NeuroCentre Magendie, Endocannabinoids and Neuroadaptation, Bordeaux, France
- NeuroCentre Magendie, Endocannabinoids and Neuroadaptation, University of Bordeaux, Bordeaux, France
| | - Carlos Matute
- Department of Neurosciences, University of the Basque Country UPV/EHU, Leioa, Spain
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Susana Mato
- Department of Neurosciences, University of the Basque Country UPV/EHU, Leioa, Spain
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Biocruces Bizkaia, Baracaldo, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota. Minneapolis, MN, USA
| | - Paulo Kofuji
- Department of Neuroscience, University of Minnesota. Minneapolis, MN, USA
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22
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Manninen T, Aćimović J, Linne ML. Analysis of Network Models with Neuron-Astrocyte Interactions. Neuroinformatics 2023; 21:375-406. [PMID: 36959372 PMCID: PMC10085960 DOI: 10.1007/s12021-023-09622-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] [Accepted: 02/01/2023] [Indexed: 03/25/2023]
Abstract
Neural networks, composed of many neurons and governed by complex interactions between them, are a widely accepted formalism for modeling and exploring global dynamics and emergent properties in brain systems. In the past decades, experimental evidence of computationally relevant neuron-astrocyte interactions, as well as the astrocytic modulation of global neural dynamics, have accumulated. These findings motivated advances in computational glioscience and inspired several models integrating mechanisms of neuron-astrocyte interactions into the standard neural network formalism. These models were developed to study, for example, synchronization, information transfer, synaptic plasticity, and hyperexcitability, as well as classification tasks and hardware implementations. We here focus on network models of at least two neurons interacting bidirectionally with at least two astrocytes that include explicitly modeled astrocytic calcium dynamics. In this study, we analyze the evolution of these models and the biophysical, biochemical, cellular, and network mechanisms used to construct them. Based on our analysis, we propose how to systematically describe and categorize interaction schemes between cells in neuron-astrocyte networks. We additionally study the models in view of the existing experimental data and present future perspectives. Our analysis is an important first step towards understanding astrocytic contribution to brain functions. However, more advances are needed to collect comprehensive data about astrocyte morphology and physiology in vivo and to better integrate them in data-driven computational models. Broadening the discussion about theoretical approaches and expanding the computational tools is necessary to better understand astrocytes' roles in brain functions.
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Affiliation(s)
- Tiina Manninen
- Faculty of Medicine and Health Technology, Tampere University, Korkeakoulunkatu 3, FI-33720, Tampere, Finland.
| | - Jugoslava Aćimović
- Faculty of Medicine and Health Technology, Tampere University, Korkeakoulunkatu 3, FI-33720, Tampere, Finland
| | - Marja-Leena Linne
- Faculty of Medicine and Health Technology, Tampere University, Korkeakoulunkatu 3, FI-33720, Tampere, Finland.
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23
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Roqué PJ, Barria A, Zhang X, Costa LG, Guizzetti M. Synaptogenesis by Cholinergic Stimulation of Astrocytes. RESEARCH SQUARE 2023:rs.3.rs-2566078. [PMID: 36824819 PMCID: PMC9949182 DOI: 10.21203/rs.3.rs-2566078/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Astrocytes release numerous factors known to contribute to the process of synaptogenesis, yet knowledge about the signals that control their release is limited. We hypothesized that neuron-derived signals stimulate astrocytes, which respond by signaling back to neurons through the modulation of astrocyte-released synaptogenic factors. Here we investigate the effect of cholinergic stimulation of astrocytes on synaptogenesis in co-cultured neurons. Using a culture system where primary rat astrocytes and primary rat neurons are first grown separately allowed us to independently manipulate astrocyte cholinergic signaling. Subsequent co-culture of pre-stimulated astrocytes with naïve neurons enabled us to assess how prior stimulation of astrocyte acetylcholine receptors uniquely modulates neuronal synapse formation. Pre-treatment of astrocytes with the acetylcholine receptor agonist carbachol increased the expression of synaptic proteins, the number of pre- and postsynaptic puncta, and the number of functional synapses in hippocampal neurons after 24 hours in co-culture. Astrocyte secretion of the synaptogenic protein thrombospondin-1 increased after cholinergic stimulation and the inhibition of the target receptor for thrombospondins prevented the observed increase in neuronal synaptic structures. Thus, we identified a novel mechanism of neuron-astrocyte-neuron communication, i.e. , neuronal release of acetylcholine stimulates astrocytes to release synaptogenic proteins leading to increased synaptogenesis in neurons. This study provides new insights into the role of neurotransmitter receptors in developing astrocytes and into our understanding of the modulation of astrocyte-induced synaptogenesis.
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24
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Peng W, Liu X, Ma G, Wu Z, Wang Z, Fei X, Qin M, Wang L, Li Y, Zhang S, Xu M. Adenosine-independent regulation of the sleep-wake cycle by astrocyte activity. Cell Discov 2023; 9:16. [PMID: 36746933 PMCID: PMC9902472 DOI: 10.1038/s41421-022-00498-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 11/20/2022] [Indexed: 02/08/2023] Open
Abstract
Astrocytes play a crucial role in regulating sleep-wake behavior, and adenosine signaling is generally thought to be involved. Here we show multiple lines of evidence supporting that modulation of the sleep-wake behavior by astrocyte Ca2+ activity could occur without adenosine signaling. In the basal forebrain and the brainstem, two brain regions that are known to be essential for sleep-wake regulation, chemogenetically-induced astrocyte Ca2+ elevation significantly modulated the sleep-wake cycle. Although astrocyte Ca2+ level positively correlated with the amount of extracellular adenosine, as revealed by a genetically encoded adenosine sensor, we found no detectable change in adenosine level after suppressing astrocyte Ca2+ elevation, and transgenic mice lacking one of the major extracellular ATP-adenosine conversion enzymes showed similar extracellular adenosine level and astrocyte Ca2+-induced sleep modulation. Furthermore, astrocyte Ca2+ is dependent primarily on local neuronal activity, causing brain region-specific regulation of the sleep-wake cycle. Thus, neural activity-dependent astrocyte activity could regulate the sleep-wake behavior independent of adenosine signaling.
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Affiliation(s)
- Wanling Peng
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China. .,University of Chinese Academy of Sciences, Beijing, China.
| | - Xiaotong Liu
- grid.9227.e0000000119573309Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China
| | - Guofen Ma
- grid.16821.3c0000 0004 0368 8293Center for Brain Science of Shanghai Children’s Medical Center, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China ,grid.16821.3c0000 0004 0368 8293Songjiang Institute and Songjiang Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhaofa Wu
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China ,grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Ziyue Wang
- grid.16821.3c0000 0004 0368 8293Center for Brain Science of Shanghai Children’s Medical Center, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China ,grid.16821.3c0000 0004 0368 8293Songjiang Institute and Songjiang Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiang Fei
- grid.9227.e0000000119573309Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, China
| | - Meiling Qin
- grid.9227.e0000000119573309Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Lizhao Wang
- grid.16821.3c0000 0004 0368 8293Center for Brain Science of Shanghai Children’s Medical Center, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China ,grid.16821.3c0000 0004 0368 8293Songjiang Institute and Songjiang Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yulong Li
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China ,grid.11135.370000 0001 2256 9319Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319PKU-IDG/McGovern Institute for Brain Research, Beijing, China
| | - Siyu Zhang
- Center for Brain Science of Shanghai Children's Medical Center, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China. .,Songjiang Institute and Songjiang Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Min Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China. .,University of Chinese Academy of Sciences, Beijing, China. .,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shangha, China.
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25
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Effect of a high-fat diet and leptin on STAT3 phosphorylation in hippocampal astrocytes. Neuroreport 2023; 34:30-37. [PMID: 36504039 DOI: 10.1097/wnr.0000000000001855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The aim of the current study was to evaluate the influence of HFD on the functionality of LepR by quantifying phosphorylated levels of 705Tyr-STAT3 in hippocampus astrocytes from mice that consumed an HFD either during the juvenile or the adult period. METHODS Five- and eight-week-old male mice, fed during 8 weeks with either control chow or HFD, received a single dose of leptin and their brains were prepared for immunofluorescence to identify double-positive GFAP/p705Tyr-STAT3 cells. RESULTS HFD intake led to increased pSTAT3 immunoreactivity in GFAP+ cells in the CA1/CA3 hippocampus areas. The effect was observed both in adolescent and adult mice. Leptin increased pSTAT3 immunoreactivity in control animals but was devoid of effect in HFD mice. HFD itself has no effect on the number of GFAP+ cells. CONCLUSIONS Our data show that regular intake of HFD enhances STAT3 signaling in CA1/CA3 astrocytes, an effect that could be linked to the increase of leptin triggered by HFD. The increase of pSTAT3 might be integral to homeostatic mechanisms aimed at maintaining hippocampus function.
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26
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Lu L, Gao Z, Wei Z, Yi M. Working memory depends on the excitatory-inhibitory balance in neuron-astrocyte network. CHAOS (WOODBURY, N.Y.) 2023; 33:013127. [PMID: 36725632 DOI: 10.1063/5.0126890] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 12/19/2022] [Indexed: 06/18/2023]
Abstract
Previous studies have shown that astrocytes are involved in information processing and working memory (WM) in the central nervous system. Here, the neuron-astrocyte network model with biological properties is built to study the effects of excitatory-inhibitory balance and neural network structures on WM tasks. It is found that the performance metrics of WM tasks under the scale-free network are higher than other network structures, and the WM task can be successfully completed when the proportion of excitatory neurons in the network exceeds 30%. There exists an optimal region for the proportion of excitatory neurons and synaptic weight that the memory performance metrics of the WM tasks are higher. The multi-item WM task shows that the spatial calcium patterns for different items overlap significantly in the astrocyte network, which is consistent with the formation of cognitive memory in the brain. Moreover, complex image tasks show that cued recall can significantly reduce systematic noise and maintain the stability of the WM tasks. The results may contribute to understand the mechanisms of WM formation and provide some inspirations into the dynamic storage and recall of memory.
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Affiliation(s)
- Lulu Lu
- School of Mathematics and Physics, China University of Geosciences, Wuhan 430074, China
| | - Zhuoheng Gao
- School of Mathematics and Physics, China University of Geosciences, Wuhan 430074, China
| | - Zhouchao Wei
- School of Mathematics and Physics, China University of Geosciences, Wuhan 430074, China
| | - Ming Yi
- School of Mathematics and Physics, China University of Geosciences, Wuhan 430074, China
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27
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Noriega‐Prieto JA, Kofuji P, Araque A. Endocannabinoid signaling in synaptic function. Glia 2023; 71:36-43. [PMID: 36408881 PMCID: PMC9679333 DOI: 10.1002/glia.24256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 07/02/2022] [Accepted: 07/25/2022] [Indexed: 01/09/2023]
Abstract
In the last decades, astrocytes have emerged as important regulatory cells actively involved in brain function by exchanging signaling with neurons. The endocannabinoid (eCB) signaling is widely present in many brain areas, being crucially involved in multiple brain functions and animal behaviors. The present review presents and discusses current evidence demonstrating that astrocytes sense eCBs released during neuronal activity and subsequently release gliotransmitters that regulate synaptic transmission and plasticity. The eCB signaling to astrocytes and the synaptic regulation mediated by astrocytes activated by eCBs are complex phenomena that exhibit exquisite spatial and temporal properties, a wide variety of downstream signaling mechanisms, and a large diversity of functional synaptic outcomes. Studies investigating this topic have revealed novel regulatory processes of synaptic function, like the lateral regulation of synaptic transmission and the active involvement of astrocytes in the spike-timing dependent plasticity, originally thought to be exclusively mediated by the coincident activity of pre- and postsynaptic neurons, following Hebbian rules for associative learning. Finally, the critical influence of astrocyte-mediated eCB signaling on animal behavior is also discussed.
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Affiliation(s)
| | - Paulo Kofuji
- Department of NeuroscienceUniversity of MinnesotaMinneapolisMinnesotaUSA
| | - Alfonso Araque
- Department of NeuroscienceUniversity of MinnesotaMinneapolisMinnesotaUSA
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28
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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: 15] [Impact Index Per Article: 15.0] [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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29
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Li WP, Su XH, Hu NY, Hu J, Li XW, Yang JM, Gao TM. Astrocytes Mediate Cholinergic Regulation of Adult Hippocampal Neurogenesis and Memory Through M 1 Muscarinic Receptor. Biol Psychiatry 2022; 92:984-998. [PMID: 35787318 DOI: 10.1016/j.biopsych.2022.04.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 04/02/2022] [Accepted: 04/27/2022] [Indexed: 11/02/2022]
Abstract
BACKGROUND In the neurogenic niches of the adult hippocampus, new functional neurons are continuously generated throughout life, and generation of these neurons has been implicated in learning and memory. Astrocytes, as components of the neurogenic niches, are critical in the regulation of adult hippocampal neurogenesis (AHN). However, little is known about how astrocytes receive and respond to extrinsic cues to regulate AHN. METHODS By using a transgenic strategy to conditionally delete astrocytic CRHM1 in mice and AAV (adeno-associated virus)-mediated overexpression of astrocytic CHRM1 specifically in the hippocampal dentate gyrus, we systematically investigated the role of astrocytic CHRM1 in the regulation of AHN and the underlying mechanisms using the combined approaches of immunohistochemistry, retrovirus labeling, electrophysiology, primary astrocyte cultures, immunoblotting, and behavioral assays. RESULTS We report that genetic ablation of CHRM1 in astrocytes led to defects in neural stem cell survival, neuronal differentiation, and maturation and integration of newborn neurons in the dentate gyrus. Astrocytic CHRM1-mediated modulation of AHN was mediated by BDNF (brain-derived neurotrophic factor) signaling. Furthermore, CHRM1 ablation in astrocytes impaired contextual fear memory. These impairments in both AHN and memory were rescued by overexpression of astrocytic CHRM1 in the dentate gyrus. CONCLUSIONS Our findings reveal a critical role for astrocytes in mediating cholinergic regulation of AHN and memory through CHRM1.
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Affiliation(s)
- Wei-Peng Li
- State Key Laboratory of Organ Failure Research, Institutes of Brain Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xiao-Hong Su
- State Key Laboratory of Organ Failure Research, Institutes of Brain Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Neng-Yuan Hu
- State Key Laboratory of Organ Failure Research, Institutes of Brain Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Jian Hu
- State Key Laboratory of Organ Failure Research, Institutes of Brain Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Xiao-Wen Li
- State Key Laboratory of Organ Failure Research, Institutes of Brain Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jian-Ming Yang
- State Key Laboratory of Organ Failure Research, Institutes of Brain Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China.
| | - Tian-Ming Gao
- State Key Laboratory of Organ Failure Research, Institutes of Brain Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, China; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.
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Ajenikoko MK, Ajagbe AO, Onigbinde OA, Okesina AA, Tijani AA. Review of Alzheimer's disease drugs and their relationship with neuron-glia interaction. IBRO Neurosci Rep 2022; 14:64-76. [PMID: 36593897 PMCID: PMC9803919 DOI: 10.1016/j.ibneur.2022.11.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 11/16/2022] [Indexed: 11/21/2022] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia worldwide. Because Alzheimer's disease has no known treatment, sufferers and their caregivers must concentrate on symptom management. Astrocytes and microglia are now known to play distinct physiological roles in synaptic function, the blood-brain barrier, and neurovascular coupling. Consequently, the search for drugs that can slow the degenerative process in dementia sufferers continues because existing drugs are designed to alleviate the symptoms of Alzheimer's disease. Drugs that address pathological changes without interfering with the normal function of glia, such as eliminating amyloid-beta deposits, are prospective treatments for neuroinflammatory illnesses. Because neuron-astrocytes-microglia interactions are so complex, developing effective, preventive, and therapeutic medications for AD will necessitate novel methodologies and strategic targets. This review focused on existing medications used in treating AD amongst which include Donepezil, Choline Alphoscerate, Galantamine, Dextromethorphan, palmitoylethanolamide, citalopram, resveratrol, and solanezumab. This review summarizes the effects of these drugs on neurons, astrocytes, and microglia interactions based on their pharmacokinetic properties, mechanism of action, dosing, and clinical presentations.
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Affiliation(s)
- Michael Kunle Ajenikoko
- Department of Anatomy, Faculty of Biomedical Sciences, Kampala International University, Western Campus, Ishaka, Uganda,Correspondence to: Department of Anatomy, Faculty of Biomedical Sciences, Kampala International University, Western Campus, Uganda.
| | - Abayomi Oyeyemi Ajagbe
- Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Nile University of Nigeria, P.M.B. 900001 Abuja, Nigeria
| | - Oluwanisola Akanji Onigbinde
- Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Nile University of Nigeria, P.M.B. 900001 Abuja, Nigeria
| | - Akeem Ayodeji Okesina
- Department of Clinical Medicine and Community Health, School of Health Sciences, College of Medicine and Health Sciences, University of Rwanda, Rwanda
| | - Ahmad Adekilekun Tijani
- Department of Anatomy, Faculty of Basic Medical Sciences, Modibbo Adama University, Yola, Nigeria
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31
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Kruyer A. Astrocyte Heterogeneity in Regulation of Synaptic Activity. Cells 2022; 11:cells11193135. [PMID: 36231097 PMCID: PMC9562199 DOI: 10.3390/cells11193135] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/02/2022] [Accepted: 10/02/2022] [Indexed: 02/07/2023] Open
Abstract
Our awareness of the number of synapse regulatory functions performed by astroglia is rapidly expanding, raising interesting questions regarding astrocyte heterogeneity and specialization across brain regions. Whether all astrocytes are poised to signal in a multitude of ways, or are instead tuned to surrounding synapses and how astroglial signaling is altered in psychiatric and cognitive disorders are fundamental questions for the field. In recent years, molecular and morphological characterization of astroglial types has broadened our ability to design studies to better analyze and manipulate specific functions of astroglia. Recent data emerging from these studies will be discussed in depth in this review. I also highlight remaining questions emerging from new techniques recently applied toward understanding the roles of astrocytes in synapse regulation in the adult brain.
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Affiliation(s)
- Anna Kruyer
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
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Becker S, Nold A, Tchumatchenko T. Modulation of working memory duration by synaptic and astrocytic mechanisms. PLoS Comput Biol 2022; 18:e1010543. [PMID: 36191056 PMCID: PMC9560596 DOI: 10.1371/journal.pcbi.1010543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 10/13/2022] [Accepted: 09/05/2022] [Indexed: 12/24/2022] Open
Abstract
Short-term synaptic plasticity and modulations of the presynaptic vesicle release rate are key components of many working memory models. At the same time, an increasing number of studies suggests a potential role of astrocytes in modulating higher cognitive function such as WM through their influence on synaptic transmission. Which influence astrocytic signaling could have on the stability and duration of WM representations, however, is still unclear. Here, we introduce a slow, activity-dependent astrocytic regulation of the presynaptic release probability in a synaptic attractor model of WM. We compare and analyze simulations of a simple WM protocol in firing rate and spiking networks with and without astrocytic regulation, and underpin our observations with analyses of the phase space dynamics in the rate network. We find that the duration and stability of working memory representations are altered by astrocytic signaling and by noise. We show that astrocytic signaling modulates the mean duration of WM representations. Moreover, if the astrocytic regulation is strong, a slow presynaptic timescale introduces a ‘window of vulnerability’, during which WM representations are easily disruptable by noise before being stabilized. We identify two mechanisms through which noise from different sources in the network can either stabilize or destabilize WM representations. Our findings suggest that (i) astrocytic regulation can act as a crucial determinant for the duration of WM representations in synaptic attractor models of WM, and (ii) that astrocytic signaling could facilitate different mechanisms for volitional top-down control of WM representations and their duration. The ability to form memories and recall them is one of the fascinating features of our brain. Working memory operates like a memory scratch pad storing ongoing information for further processing. Here, we present a computational model dissecting the influence of astrocytes on the stability and duration of working memories. We find that a long astrocytic time constant can influence the mean duration of working memory representations and generate a “window of vulnerability”, during which some memories are tagged for long-term survival while some are terminated. The fraction of memories in the survival and termination groups could be regulated by adjusting the strength of astrocytic feedback or its time constant. This indicates that astrocytic signaling can be viewed as a candidate mechanism for top-down control of working memory representations and their duration.
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Affiliation(s)
- Sophia Becker
- Laboratory of Computational Neuroscience, Brain Mind Institute, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Theory of Neural Dynamics group, Max Planck Institute for Brain Research, Frankfurt am Main, Germany
| | - Andreas Nold
- Theory of Neural Dynamics group, Max Planck Institute for Brain Research, Frankfurt am Main, Germany
- Institute of Experimental Epileptology and Cognition Research, Life and Brain Center, Universitätsklinikum Bonn, Bonn, Germany
| | - Tatjana Tchumatchenko
- Theory of Neural Dynamics group, Max Planck Institute for Brain Research, Frankfurt am Main, Germany
- Institute of Experimental Epileptology and Cognition Research, Life and Brain Center, Universitätsklinikum Bonn, Bonn, Germany
- Institute for Physiological Chemistry, Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
- * E-mail:
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Ca 2+-modulated photoactivatable imaging reveals neuron-astrocyte glutamatergic circuitries within the nucleus accumbens. Nat Commun 2022; 13:5272. [PMID: 36071061 PMCID: PMC9452556 DOI: 10.1038/s41467-022-33020-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 08/25/2022] [Indexed: 11/11/2022] Open
Abstract
Astrocytes are key elements of brain circuits that are involved in different aspects of the neuronal physiology relevant to brain functions. Although much effort is being made to understand how the biology of astrocytes affects brain circuits, astrocytic network heterogeneity and plasticity is still poorly defined. Here, we have combined structural and functional imaging of astrocyte activity recorded in mice using the Ca2+-modulated photoactivatable ratiometric integrator and specific optostimulation of glutamatergic pathways to map the functional neuron-astrocyte circuitries in the nucleus accumbens (NAc). We showed pathway-specific astrocytic responses induced by selective optostimulation of main inputs from the prefrontal cortex, basolateral amygdala, and ventral hippocampus. Furthermore, co-stimulation of glutamatergic pathways induced non-linear Ca2+-signaling integration, revealing integrative properties of NAc astrocytes. All these results demonstrate the existence of specific neuron-astrocyte circuits in the NAc, providing an insight to the understanding of how the NAc integrates information. Neuron-astrocyte communication is fundamental for brain physiology, yet the heterogeneity in the functional interaction between these two elements remains poorly understood. Here we show how different neuron-astrocyte networks integrate information from distinct glutamatergic inputs.
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Abstract
Astrocytic calcium dynamics has been implicated in the encoding of sensory information1-5, and modulation of calcium in astrocytes has been shown to affect behaviour6-10. However, longitudinal investigation of the real-time calcium activity of astrocytes in the hippocampus of awake mice is lacking. Here we used two-photon microscopy to chronically image CA1 astrocytes as mice ran in familiar or new virtual environments to obtain water rewards. We found that astrocytes exhibit persistent ramping activity towards the reward location in a familiar environment, but not in a new one. Shifting the reward location within a familiar environment also resulted in diminished ramping. After additional training, as the mice became familiar with the new context or new reward location, the ramping was re-established. Using linear decoders, we could predict the location of the mouse in a familiar environment from astrocyte activity alone. We could not do the same in a new environment, suggesting that the spatial modulation of astrocytic activity is experience dependent. Our results indicate that astrocytes can encode the expected reward location in spatial contexts, thereby extending their known computational abilities and their role in cognitive functions.
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35
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Butcher JB, Sims RE, Ngum NM, Bazzari AH, Jenkins SI, King M, Hill EJ, Nagel DA, Fox K, Parri HR, Glazewski S. A requirement for astrocyte IP3R2 signaling for whisker experience-dependent depression and homeostatic upregulation in the mouse barrel cortex. Front Cell Neurosci 2022; 16:905285. [PMID: 36090792 PMCID: PMC9452848 DOI: 10.3389/fncel.2022.905285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 07/06/2022] [Indexed: 11/19/2022] Open
Abstract
Changes to sensory experience result in plasticity of synapses in the cortex. This experience-dependent plasticity (EDP) is a fundamental property of the brain. Yet, while much is known about neuronal roles in EDP, very little is known about the role of astrocytes. To address this issue, we used the well-described mouse whiskers-to-barrel cortex system, which expresses a number of forms of EDP. We found that all-whisker deprivation induced characteristic experience-dependent Hebbian depression (EDHD) followed by homeostatic upregulation in L2/3 barrel cortex of wild type mice. However, these changes were not seen in mutant animals (IP3R2–/–) that lack the astrocyte-expressed IP3 receptor subtype. A separate paradigm, the single-whisker experience, induced potentiation of whisker-induced response in both wild-type (WT) mice and IP3R2–/– mice. Recordings in ex vivo barrel cortex slices reflected the in vivo results so that long-term depression (LTD) could not be elicited in slices from IP3R2–/– mice, but long-term potentiation (LTP) could. Interestingly, 1 Hz stimulation inducing LTD in WT paradoxically resulted in NMDAR-dependent LTP in slices from IP3R2–/– animals. The LTD to LTP switch was mimicked by acute buffering astrocytic [Ca2+]i in WT slices. Both WT LTD and IP3R2–/– 1 Hz LTP were mediated by non-ionotropic NMDAR signaling, but only WT LTD was P38 MAPK dependent, indicating an underlying mechanistic switch. These results demonstrate a critical role for astrocytic [Ca2+]i in several EDP mechanisms in neocortex.
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Affiliation(s)
- John B. Butcher
- School of Life Sciences, Keele University, Keele, United Kingdom
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - Robert E. Sims
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - Neville M. Ngum
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - Amjad H. Bazzari
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - Stuart I. Jenkins
- Neural Tissue Engineering Group, Institute for Science and Technology in Medicine (ISTM), Keele University, Keele, United Kingdom
| | - Marianne King
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - Eric J. Hill
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - David A. Nagel
- Aston Medical School, Aston Medical Research Institute, Aston University, Birmingham, United Kingdom
| | - Kevin Fox
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - H. Rheinallt Parri
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
- *Correspondence: H. Rheinallt Parri,
| | - Stanislaw Glazewski
- School of Life Sciences, Keele University, Keele, United Kingdom
- Stanislaw Glazewski,
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36
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Ivanov VA, Michmizos KP. Astrocytes Learn to Detect and Signal Deviations from Critical Brain Dynamics. Neural Comput 2022; 34:2047-2074. [PMID: 36027803 DOI: 10.1162/neco_a_01532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 06/03/2022] [Indexed: 11/04/2022]
Abstract
Astrocytes are nonneuronal brain cells that were recently shown to actively communicate with neurons and are implicated in memory, learning, and regulation of cognitive states. Interestingly, these information processing functions are also closely linked to the brain's ability to self-organize at a critical phase transition. Investigating the mechanistic link between astrocytes and critical brain dynamics remains beyond the reach of cellular experiments, but it becomes increasingly approachable through computational studies. We developed a biologically plausible computational model of astrocytes to analyze how astrocyte calcium waves can respond to changes in underlying network dynamics. Our results suggest that astrocytes detect synaptic activity and signal directional changes in neuronal network dynamics using the frequency of their calcium waves. We show that this function may be facilitated by receptor scaling plasticity by enabling astrocytes to learn the approximate information content of input synaptic activity. This resulted in a computationally simple, information-theoretic model, which we demonstrate replicating the signaling functionality of the biophysical astrocyte model with receptor scaling. Our findings provide several experimentally testable hypotheses that offer insight into the regulatory role of astrocytes in brain information processing.
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Affiliation(s)
- Vladimir A Ivanov
- Computational Brain Lab, Department of Computer Science, Rutgers University, Piscataway, NJ 08854, U.S.A.
| | - Konstantinos P Michmizos
- Computational Brain Lab, Department of Computer Science, Rutgers University, Piscataway, NJ 08854, U.S.A.
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37
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Malfunction of astrocyte and cholinergic input is involved in postoperative impairment of hippocampal synaptic plasticity and cognitive function. Neuropharmacology 2022; 217:109191. [PMID: 35835213 DOI: 10.1016/j.neuropharm.2022.109191] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 06/04/2022] [Accepted: 07/07/2022] [Indexed: 12/28/2022]
Abstract
Postoperative delirium (POD) occurs in a few days after major surgery under general anesthesia and may cause serious health problems. However, effective intervention and treatment remain unavailable because the underlying mechanisms have far been elucidated. In the present study, we explored the role of the malfunctioned astrocytes in POD. Our results showed that mice with tibia fracture displayed spatial and temporal memory impairments, reduced LTP, and activated astrocytes in the hippocampus in early postoperative stage. Using electrophysiological and Ca2+ imaging techniques in hippocampal slices, we demonstrated the malfunctions of astrocytes in surgery mice: depolarized resting membrane potential, higher membrane conductance and capacitance, and attenuated Ca2+ elevation in response to external stimulation. The degraded calcium signaling in hippocampal astrocytes in surgery mice was restored by correcting the diminution of acetylcholine release with galantamine. Furthermore, pharmacologically blocking astrocyte activation with fluorocitrate and enhancing cholinergic inputs with galantamine normalized hippocampal LTP in surgery mice. Finally, inhibition of astrocyte activation with fluorocitrate in the hippocampus improved cognitive function in surgery mice. Therefore, the prevention of astrocyte activation may be a valuable strategy for the intervention of cognitive dysfunction in POD, and acetylcholine receptors may be valid drug targets for this purpose.
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38
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Sobolczyk M, Boczek T. Astrocytic Calcium and cAMP in Neurodegenerative Diseases. Front Cell Neurosci 2022; 16:889939. [PMID: 35663426 PMCID: PMC9161693 DOI: 10.3389/fncel.2022.889939] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/05/2022] [Indexed: 12/18/2022] Open
Abstract
It is commonly accepted that the role of astrocytes exceeds far beyond neuronal scaffold and energy supply. Their unique morphological and functional features have recently brough much attention as it became evident that they play a fundamental role in neurotransmission and interact with synapses. Synaptic transmission is a highly orchestrated process, which triggers local and transient elevations in intracellular Ca2+, a phenomenon with specific temporal and spatial properties. Presynaptic activation of Ca2+-dependent adenylyl cyclases represents an important mechanism of synaptic transmission modulation. This involves activation of the cAMP-PKA pathway to regulate neurotransmitter synthesis, release and storage, and to increase neuroprotection. This aspect is of paramount importance for the preservation of neuronal survival and functionality in several pathological states occurring with progressive neuronal loss. Hence, the aim of this review is to discuss mutual relationships between cAMP and Ca2+ signaling and emphasize those alterations at the Ca2+/cAMP crosstalk that have been identified in neurodegenerative disorders, such as Alzheimer's and Parkinson's disease.
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39
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Renz-Polster H, Tremblay ME, Bienzle D, Fischer JE. The Pathobiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: The Case for Neuroglial Failure. Front Cell Neurosci 2022; 16:888232. [PMID: 35614970 PMCID: PMC9124899 DOI: 10.3389/fncel.2022.888232] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 04/13/2022] [Indexed: 12/20/2022] Open
Abstract
Although myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) has a specific and distinctive profile of clinical features, the disease remains an enigma because causal explanation of the pathobiological matrix is lacking. Several potential disease mechanisms have been identified, including immune abnormalities, inflammatory activation, mitochondrial alterations, endothelial and muscular disturbances, cardiovascular anomalies, and dysfunction of the peripheral and central nervous systems. Yet, it remains unclear whether and how these pathways may be related and orchestrated. Here we explore the hypothesis that a common denominator of the pathobiological processes in ME/CFS may be central nervous system dysfunction due to impaired or pathologically reactive neuroglia (astrocytes, microglia and oligodendrocytes). We will test this hypothesis by reviewing, in reference to the current literature, the two most salient and widely accepted features of ME/CFS, and by investigating how these might be linked to dysfunctional neuroglia. From this review we conclude that the multifaceted pathobiology of ME/CFS may be attributable in a unifying manner to neuroglial dysfunction. Because the two key features - post exertional malaise and decreased cerebral blood flow - are also recognized in a subset of patients with post-acute sequelae COVID, we suggest that our findings may also be pertinent to this entity.
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Affiliation(s)
- Herbert Renz-Polster
- Division of General Medicine, Center for Preventive Medicine and Digital Health Baden-Württemberg (CPD-BW), University Medicine Mannheim, Heidelberg University, Mannheim, Germany
| | - Marie-Eve Tremblay
- Axe Neurosciences, Centre de recherche du CHU de Québec, Université Laval, Quebec, QC, Canada
- Département de Médecine Moléculaire, Université Laval, Quebec, QC, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Center for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, Canada
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada
| | - Dorothee Bienzle
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Joachim E. Fischer
- Division of General Medicine, Center for Preventive Medicine and Digital Health Baden-Württemberg (CPD-BW), University Medicine Mannheim, Heidelberg University, Mannheim, Germany
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40
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Allen M, Huang BS, Notaras MJ, Lodhi A, Barrio-Alonso E, Lituma PJ, Wolujewicz P, Witztum J, Longo F, Chen M, Greening DW, Klann E, Ross ME, Liston C, Colak D. Astrocytes derived from ASD individuals alter behavior and destabilize neuronal activity through aberrant Ca 2+ signaling. Mol Psychiatry 2022; 27:2470-2484. [PMID: 35365802 PMCID: PMC9135629 DOI: 10.1038/s41380-022-01486-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 02/01/2022] [Accepted: 02/11/2022] [Indexed: 01/08/2023]
Abstract
The cellular mechanisms of autism spectrum disorder (ASD) are poorly understood. Cumulative evidence suggests that abnormal synapse function underlies many features of this disease. Astrocytes regulate several key neuronal processes, including the formation of synapses and the modulation of synaptic plasticity. Astrocyte abnormalities have also been identified in the postmortem brain tissue of ASD individuals. However, it remains unclear whether astrocyte pathology plays a mechanistic role in ASD, as opposed to a compensatory response. To address this, we combined stem cell culturing with transplantation techniques to determine disease-specific properties inherent to ASD astrocytes. We demonstrate that ASD astrocytes induce repetitive behavior as well as impair memory and long-term potentiation when transplanted into the healthy mouse brain. These in vivo phenotypes were accompanied by reduced neuronal network activity and spine density caused by ASD astrocytes in hippocampal neurons in vitro. Transplanted ASD astrocytes also exhibit exaggerated Ca2+ fluctuations in chimeric brains. Genetic modulation of evoked Ca2+ responses in ASD astrocytes modulates behavior and neuronal activity deficits. Thus, this study determines that astrocytes derived from ASD iPSCs are sufficient to induce repetitive behavior as well as cognitive deficit, suggesting a previously unrecognized primary role for astrocytes in ASD.
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Affiliation(s)
- Megan Allen
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Ben S Huang
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA.,Department of Psychiatry, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Michael J Notaras
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Aiman Lodhi
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Estibaliz Barrio-Alonso
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Pablo J Lituma
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Paul Wolujewicz
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Jonathan Witztum
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Francesco Longo
- Center for Neural Science, New York University, New York, NY, USA
| | - Maoshan Chen
- Molecular Proteomics, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, VIC, Australia.,Baker Department of Cardiovascular Research, Translation and Implementation, La Trobe University, Melbourne, VIC, Australia.,Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - David W Greening
- Molecular Proteomics, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, VIC, Australia.,Baker Department of Cardiovascular Research, Translation and Implementation, La Trobe University, Melbourne, VIC, Australia.,Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY, USA
| | - M Elizabeth Ross
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Conor Liston
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA.,Department of Psychiatry, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Dilek Colak
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA. .,Gale and Ira Drukier Institute for Children's Health, Weill Cornell Medicine, Cornell University, New York, NY, USA.
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41
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Linne ML, Aćimović J, Saudargiene A, Manninen T. Neuron-Glia Interactions and Brain Circuits. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1359:87-103. [PMID: 35471536 DOI: 10.1007/978-3-030-89439-9_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Recent evidence suggests that glial cells take an active role in a number of brain functions that were previously attributed solely to neurons. For example, astrocytes, one type of glial cells, have been shown to promote coordinated activation of neuronal networks, modulate sensory-evoked neuronal network activity, and influence brain state transitions during development. This reinforces the idea that astrocytes not only provide the "housekeeping" for the neurons, but that they also play a vital role in supporting and expanding the functions of brain circuits and networks. Despite this accumulated knowledge, the field of computational neuroscience has mostly focused on modeling neuronal functions, ignoring the glial cells and the interactions they have with the neurons. In this chapter, we introduce the biology of neuron-glia interactions, summarize the existing computational models and tools, and emphasize the glial properties that may be important in modeling brain functions in the future.
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Affiliation(s)
- Marja-Leena Linne
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
| | - Jugoslava Aćimović
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Ausra Saudargiene
- Neuroscience Institute, Lithuanian University of Health Sciences, Kaunas, Lithuania.,Department of Informatics, Vytautas Magnus University, Kaunas, Lithuania
| | - Tiina Manninen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
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42
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Oliveira JF, Araque A. Astrocyte regulation of neural circuit activity and network states. Glia 2022; 70:1455-1466. [PMID: 35460131 PMCID: PMC9232995 DOI: 10.1002/glia.24178] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 02/23/2022] [Accepted: 02/27/2022] [Indexed: 12/13/2022]
Abstract
Astrocytes are known to influence neuronal activity through different mechanisms, including the homeostatic control of extracellular levels of ions and neurotransmitters and the exchange of signaling molecules that regulate synaptic formation, structure, and function. While a great effort done in the past has defined many molecular mechanisms and cellular processes involved in astrocyte-neuron interactions at the cellular level, the consequences of these interactions at the network level in vivo have only relatively recently been identified. This review describes and discusses recent findings on the regulatory effects of astrocytes on the activity of neuronal networks in vivo. Accumulating but still limited, evidence indicates that astrocytes regulate neuronal network rhythmic activity and synchronization as well as brain states. These studies demonstrate a critical contribution of astrocytes to brain activity and are paving the way for a more thorough understanding of the cellular bases of brain function.
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Affiliation(s)
- João Filipe Oliveira
- Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal.,ICVS/3B's-PT Government Associate Laboratory, Braga, Portugal.,IPCA-EST-2Ai, Polytechnic Institute of Cávado and Ave, Applied Artificial Intelligence Laboratory, Campus of IPCA, Barcelos, Portugal
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
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Jackson JG, Krizman E, Takano H, Lee M, Choi GH, Putt ME, Robinson MB. Activation of Glutamate Transport Increases Arteriole Diameter in v ivo: Implications for Neurovascular Coupling. Front Cell Neurosci 2022; 16:831061. [PMID: 35308116 PMCID: PMC8930833 DOI: 10.3389/fncel.2022.831061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/24/2022] [Indexed: 11/21/2022] Open
Abstract
In order to meet the energetic demands of cell-to-cell signaling, increases in local neuronal signaling are matched by a coordinated increase in local blood flow, termed neurovascular coupling. Multiple different signals from neurons, astrocytes, and pericytes contribute to this control of blood flow. Previously, several groups demonstrated that inhibition/ablation of glutamate transporters attenuates the neurovascular response. However, it was not determined if glutamate transporter activation was sufficient to increase blood flow. Here, we used multiphoton imaging to monitor the diameter of fluorescently labeled cortical arterioles in anesthetized C57/B6J mice. We delivered vehicle, glutamate transporter substrates, or a combination of a glutamate transporter substrate with various pharmacologic agents via a glass micropipette while simultaneously visualizing changes in arteriole diameter. We developed a novel image analysis method to automate the measurement of arteriole diameter in these time-lapse analyses. Using this workflow, we first conducted pilot experiments in which we focally applied L-glutamate, D-aspartate, or L-threo-hydroxyaspartate (L-THA) and measured arteriole responses as proof of concept. We subsequently applied the selective glutamate transport substrate L-THA (applied at concentrations that do not activate glutamate receptors). We found that L-THA evoked a significantly larger dilation than that observed with focal saline application. This response was blocked by co-application of the potent glutamate transport inhibitor, L-(2S,3S)-3-[3-[4-(trifluoromethyl)-benzoylamino]benzyloxy]-aspartate (TFB-TBOA). Conversely, we were unable to demonstrate a reduction of this effect through co-application of a cocktail of glutamate and GABA receptor antagonists. These studies provide the first direct evidence that activation of glutamate transport is sufficient to increase arteriole diameter. We explored potential downstream mechanisms mediating this transporter-mediated dilation by using a Ca2+ chelator or inhibitors of reversed-mode Na+/Ca2+ exchange, nitric oxide synthetase, or cyclo-oxygenase. The estimated effects and confidence intervals suggested some form of inhibition for a number of these inhibitors. Limitations to our study design prevented definitive conclusions with respect to these downstream inhibitors; these limitations are discussed along with possible next steps. Understanding the mechanisms that control blood flow are important because changes in blood flow/energy supply are implicated in several neurodegenerative disorders and are used as a surrogate measure of neuronal activity in widely used techniques such as functional magnetic resonance imaging (fMRI).
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Affiliation(s)
- Joshua G. Jackson
- Children’s Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA, United States
| | - Elizabeth Krizman
- Children’s Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA, United States
| | - Hajime Takano
- Children’s Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Meredith Lee
- Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Grace H. Choi
- Department of Biostatistics, Epidemiology & Informatics, University of Pennsylvania, Philadelphia, PA, United States
| | - Mary E. Putt
- Department of Biostatistics, Epidemiology & Informatics, University of Pennsylvania, Philadelphia, PA, United States
| | - Michael B. Robinson
- Children’s Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA, United States
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Distinct roles of astroglia and neurons in synaptic plasticity and memory. Mol Psychiatry 2022; 27:873-885. [PMID: 34642458 DOI: 10.1038/s41380-021-01332-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 09/17/2021] [Accepted: 09/29/2021] [Indexed: 12/17/2022]
Abstract
Long-term potentiation (LTP) in the hippocampus is the most studied form of synaptic plasticity. Temporal integration of synaptic inputs is essential in synaptic plasticity and is assumed to be achieved through Ca2+ signaling in neurons and astroglia. However, whether these two cell types play different roles in LTP remain unknown. Here, we found that through the integration of synaptic inputs, astrocyte inositol triphosphate (IP3) receptor type 2 (IP3R2)-dependent Ca2+ signaling was critical for late-phase LTP (L-LTP) but not early-phase LTP (E-LTP). Moreover, this process was mediated by astrocyte-derived brain-derived neurotrophic factor (BDNF). In contrast, neuron-derived BDNF was critical for both E-LTP and L-LTP. Importantly, the dynamic differences in BDNF secretion play a role in modulating distinct forms of LTP. Moreover, astrocyte- and neuron-derived BDNF exhibited different roles in memory. These observations enriched our knowledge of LTP and memory at the cellular level and implied distinct roles of astrocytes and neurons in information integration.
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Landucci E, Mazzantini C, Lana D, Giovannini MG, Pellegrini-Giampietro DE. Neuronal and Astrocytic Morphological Alterations Driven by Prolonged Exposure with Δ9-Tetrahydrocannabinol but Not Cannabidiol. TOXICS 2022; 10:toxics10020048. [PMID: 35202235 PMCID: PMC8879505 DOI: 10.3390/toxics10020048] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 12/24/2022]
Abstract
Cannabis derivatives are largely used in the general population for recreational and medical purposes, with the highest prevalence among adolescents, but chronic use and abuse has raised medical concerns. We investigated the prolonged effects of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in organotypic hippocampal slices from P7 rats cultured for 2 weeks. Cell death in the CA1 subregion of slices was quantified by propidium iodide (PI) fluorescence, pre-synaptic and post-synaptic marker proteins were analysed by Western blotting and neurodegeneration and astrocytic alterations by NeuN and GFAP by immunofluorescence and confocal laser microscopy. The statistical significance of differences was analysed using ANOVA with a post hoc Dunnett w-test (PI fluorescence intensities and Western blots) or Newman–Keuls (immunohistochemistry data) for multiple comparisons. A probability value (P) of < 0.05 was considered significant. Prolonged (72 h) THC or CBD incubation did not induce cell death but caused modifications in the expression of synaptic proteins and morphological alterations in neurons and astrocytes. In particular, the expression of PSD95 was reduced following incubation for 72 h with THC and was increased following incubation with CBD. THC for 72 h caused disorganisation of CA1 stratum pyramidalis (SP) and complex morphological modifications in a significant number of pyramidal neurons and in astrocytes. Our results suggest that THC or CBD prolonged exposure induce different effects in the hippocampus. In particular, 72 h of THC exposure induced neuronal and glia alterations that must draw our attention to the effects that relatively prolonged use might cause, especially in adolescents.
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46
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Aramideh JA, Vidal-Itriago A, Morsch M, Graeber MB. Cytokine Signalling at the Microglial Penta-Partite Synapse. Int J Mol Sci 2021; 22:ijms222413186. [PMID: 34947983 PMCID: PMC8708012 DOI: 10.3390/ijms222413186] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 12/28/2022] Open
Abstract
Microglial cell processes form part of a subset of synaptic contacts that have been dubbed microglial tetra-partite or quad-partite synapses. Since tetrapartite may also refer to the presence of extracellular matrix components, we propose the more precise term microglial penta-partite synapse for synapses that show a microglial cell process in close physical proximity to neuronal and astrocytic synaptic constituents. Microglial cells are now recognised as key players in central nervous system (CNS) synaptic changes. When synaptic plasticity involving microglial penta-partite synapses occurs, microglia may utilise their cytokine arsenal to facilitate the generation of new synapses, eliminate those that are not needed anymore, or modify the molecular and structural properties of the remaining synaptic contacts. In addition, microglia–synapse contacts may develop de novo under pathological conditions. Microglial penta-partite synapses have received comparatively little attention as unique sites in the CNS where microglial cells, cytokines and other factors they release have a direct influence on the connections between neurons and their function. It concerns our understanding of the penta-partite synapse where the confusion created by the term “neuroinflammation” is most counterproductive. The mere presence of activated microglia or the release of their cytokines may occur independent of inflammation, and penta-partite synapses are not usually active in a neuroimmunological sense. Clarification of these details is the main purpose of this review, specifically highlighting the relationship between microglia, synapses, and the cytokines that can be released by microglial cells in health and disease.
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Affiliation(s)
- Jason Abbas Aramideh
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia;
| | - Andres Vidal-Itriago
- Faculty of Medicine, Health & Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia; (A.V.-I.); (M.M.)
| | - Marco Morsch
- Faculty of Medicine, Health & Human Sciences, Macquarie Medical School, Macquarie University, Sydney, NSW 2109, Australia; (A.V.-I.); (M.M.)
| | - Manuel B. Graeber
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia;
- Correspondence:
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Fear learning induces α7-nicotinic acetylcholine receptor-mediated astrocytic responsiveness that is required for memory persistence. Nat Neurosci 2021; 24:1686-1698. [PMID: 34782794 DOI: 10.1038/s41593-021-00949-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 09/27/2021] [Indexed: 01/28/2023]
Abstract
Memory persistence is a fundamental cognitive process for guiding behaviors and is considered to rely mostly on neuronal and synaptic plasticity. Whether and how astrocytes contribute to memory persistence is largely unknown. Here, by using two-photon Ca2+ imaging in head-fixed mice and fiber photometry in freely moving mice, we show that aversive sensory stimulation activates α7-nicotinic acetylcholine receptors (nAChRs) in a subpopulation of astrocytes in the auditory cortex. We demonstrate that fear learning causes the de novo induction of sound-evoked Ca2+ transients in these astrocytes. The astrocytic responsiveness persisted over days along with fear memory and disappeared in animals that underwent extinction of learned freezing behavior. Conditional genetic deletion of α7-nAChRs in astrocytes significantly impaired fear memory persistence. We conclude that learning-acquired, α7-nAChR-dependent astrocytic responsiveness is an integral part of the cellular substrate underlying memory persistence.
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Fukushi I, Takeda K, Pokorski M, Kono Y, Yoshizawa M, Hasebe Y, Nakao A, Mori Y, Onimaru H, Okada Y. Activation of Astrocytes in the Persistence of Post-hypoxic Respiratory Augmentation. Front Physiol 2021; 12:757731. [PMID: 34690820 PMCID: PMC8531090 DOI: 10.3389/fphys.2021.757731] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/15/2021] [Indexed: 11/16/2022] Open
Abstract
Acute hypoxia increases ventilation. After cessation of hypoxia loading, ventilation decreases but remains above the pre-exposure baseline level for a time. However, the mechanism of this post-hypoxic persistent respiratory augmentation (PHRA), which is a short-term potentiation of breathing, has not been elucidated. We aimed to test the hypothesis that astrocytes are involved in PHRA. To this end, we investigated hypoxic ventilatory responses by whole-body plethysmography in unanesthetized adult mice. The animals breathed room air, hypoxic gas mixture (7% O2, 93% N2) for 2min, and again room air for 10min before and after i.p. administration of low (100mg/kg) and high (300mg/kg) doses of arundic acid (AA), an astrocyte inhibitor. AA suppressed PHRA, with the high dose decreasing ventilation below the pre-hypoxic level. Further, we investigated the role of the astrocytic TRPA1 channel, a putative ventilatory hypoxia sensor, in PHRA using astrocyte-specific Trpa1 knockout (asTrpa1−/−) and floxed Trpa1 (Trpa1f/f) mice. In both Trpa1f/f and asTrpa1−/− mice, PHRA was noticeable, indicating that the astrocyte TRPA1 channel was not directly involved in PHRA. Taken together, these results indicate that astrocytes mediate the PHRA by mechanisms other than TRPA1 channels that are engaged in hypoxia sensing.
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Affiliation(s)
- Isato Fukushi
- Faculty of Health Sciences, Uekusa Gakuen University, Chiba, Japan.,Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
| | - Kotaro Takeda
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Faculty of Rehabilitation, School of Healthcare, Fujita Health University, Toyoake, Japan
| | - Mieczyslaw Pokorski
- Institute of Health Sciences, University of Opole, Opole, Poland.,Faculty of Health Sciences, The Jan Dlugosz University in Czestochowa, Czestochowa, Poland
| | - Yosuke Kono
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Masashi Yoshizawa
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Yohei Hasebe
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Akito Nakao
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Yasuo Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, Tokyo, Japan
| | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
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49
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Astrocyte Gliotransmission in the Regulation of Systemic Metabolism. Metabolites 2021; 11:metabo11110732. [PMID: 34822390 PMCID: PMC8623475 DOI: 10.3390/metabo11110732] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 12/28/2022] Open
Abstract
Normal brain function highly relies on the appropriate functioning of astrocytes. These glial cells are strategically situated between blood vessels and neurons, provide significant substrate support to neuronal demand, and are sensitive to neuronal activity and energy-related molecules. Astrocytes respond to many metabolic conditions and regulate a wide array of physiological processes, including cerebral vascular remodeling, glucose sensing, feeding, and circadian rhythms for the control of systemic metabolism and behavior-related responses. This regulation ultimately elicits counterregulatory mechanisms in order to couple whole-body energy availability with brain function. Therefore, understanding the role of astrocyte crosstalk with neighboring cells via the release of molecules, e.g., gliotransmitters, into the parenchyma in response to metabolic and neuronal cues is of fundamental relevance to elucidate the distinct roles of these glial cells in the neuroendocrine control of metabolism. Here, we review the mechanisms underlying astrocyte-released gliotransmitters that have been reported to be crucial for maintaining homeostatic regulation of systemic metabolism.
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50
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Twible C, Abdo R, Zhang Q. Astrocyte Role in Temporal Lobe Epilepsy and Development of Mossy Fiber Sprouting. Front Cell Neurosci 2021; 15:725693. [PMID: 34658792 PMCID: PMC8514632 DOI: 10.3389/fncel.2021.725693] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/02/2021] [Indexed: 11/13/2022] Open
Abstract
Epilepsy affects approximately 50 million people worldwide, with 60% of adult epilepsies presenting an onset of focal origin. The most common focal epilepsy is temporal lobe epilepsy (TLE). The role of astrocytes in the presentation and development of TLE has been increasingly studied and discussed within the literature. The most common histopathological diagnosis of TLE is hippocampal sclerosis. Hippocampal sclerosis is characterized by neuronal cell loss within the Cornu ammonis and reactive astrogliosis. In some cases, mossy fiber sprouting may be observed. Mossy fiber sprouting has been controversial in its contribution to epileptogenesis in TLE patients, and the mechanisms surrounding the phenomenon have yet to be elucidated. Several studies have reported that mossy fiber sprouting has an almost certain co-existence with reactive astrogliosis within the hippocampus under epileptic conditions. Astrocytes are known to play an important role in the survival and axonal outgrowth of central and peripheral nervous system neurons, pointing to a potential role of astrocytes in TLE and associated cellular alterations. Herein, we review the recent developments surrounding the role of astrocytes in the pathogenic process of TLE and mossy fiber sprouting, with a focus on proposed signaling pathways and cellular mechanisms, histological observations, and clinical correlations in human patients.
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Affiliation(s)
- Carolyn Twible
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada
| | - Rober Abdo
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada.,Department of Anatomy and Cell Biology, Western University, London, ON, Canada
| | - Qi Zhang
- Department of Pathology and Lab Medicine, Western University, London, ON, Canada.,Department of Pathology and Lab Medicine, London Health Sciences Centre, University Hospital, London, ON, Canada
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