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Yokoyama K, Hiraoka Y, Abe Y, Tanaka KF. Visualization of myelin-forming oligodendrocytes in the adult mouse brain. J Neurochem 2024. [PMID: 39233334 DOI: 10.1111/jnc.16218] [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: 03/26/2024] [Revised: 08/10/2024] [Accepted: 08/20/2024] [Indexed: 09/06/2024]
Abstract
Oligodendrocyte (OL) differentiation from oligodendrocyte precursor cells (OPCs) is considered to result in two populations: premyelinating and myelinating OLs. Recent single-cell RNA sequence data subdivided these populations into newly formed (NFOLs), myelin-forming (MFOLs), and mature (MOLs) oligodendrocytes. However, which newly proposed population corresponds to premyelinating or myelinating OLs is unknown. We focused on the NFOL-specific long non-coding oligodendrocyte 1 gene (LncOL1) and sought to label NFOLs under the control of the LncOL1 promoter using a tetracycline-controllable gene induction system. We demonstrated that LncOL1 was expressed by premyelinating OLs and that the MFOL-specific gene, Ctps, was not, indicating that NFOLs correspond to premyelinating OLs and that MFOLs and MOLs correspond to myelinating OLs. We then generated a LncOL1-tTA mouse in which a tetracycline transactivator (tTA) cassette was inserted downstream from the LncOL1 transcription initiation site. By crossing the LncOL1-tTA mice with tetO reporter mice, we generated LncOL1-tTA::tetO-yellow fluorescent protein (YFP) double-transgenic (LncOL1-YFP) mice. Although LncOL1 is non-coding, YFP was detected in LncOL1-YFP mice, indicating successful tTA translation. Unexpectedly, we found that the morphology of LncOL1-tTA-driven YFP+ cells was distinct from that of LncOL1+ premyelinating OLs and that the labeled cells instead appeared as myelinating OLs. We demonstrated from their RNA expression that YFP-labeled OLs were MFOLs, but not MOLs. Using the unique property of delayed YFP induction, we sought to determine whether MFOLs are constantly supplied from OPCs and differentiate into MOLs, or whether MFOLs pause their differentiation and sustain this stage in the adult brain. To achieve this objective, we irradiated adult LncOL1-YFP brains with X-rays to deplete dividing OPCs and their progeny. The irradiation extinguished YFP-labeled OLs, indicating that adult OPCs differentiated into MOLs during a single period. We established a new transgenic mouse line that genetically labels MFOLs, providing a reliable tool for investigating the dynamics of adult oligodendrogenesis.
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Affiliation(s)
- Kiichi Yokoyama
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan
| | - Yuichi Hiraoka
- Laboratory of Molecular Neuroscience, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
- Laboratory of Genome Editing for Biomedical Research, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yoshifumi Abe
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan
| | - Kenji F Tanaka
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo, Japan
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2
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Tan W, Ikoma Y, Takahashi Y, Konno A, Hirai H, Hirase H, Matsui K. Anxiety control by astrocytes in the lateral habenula. Neurosci Res 2024; 205:1-15. [PMID: 38311032 DOI: 10.1016/j.neures.2024.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/17/2024] [Accepted: 01/21/2024] [Indexed: 02/06/2024]
Abstract
The potential role of astrocytes in lateral habenula (LHb) in modulating anxiety was explored in this study. The habenula are a pair of small nuclei located above the thalamus, known for their involvement in punishment avoidance and anxiety. Herein, we observed an increase in theta-band oscillations of local field potentials (LFPs) in the LHb when mice were exposed to anxiety-inducing environments. Electrical stimulation of LHb at theta-band frequency promoted anxiety-like behavior. Calcium (Ca2+) levels and pH in the cytosol of astrocytes and local brain blood volume changes were studied in mice expressing either a Ca2+ or a pH sensor protein specifically in astrocytes and mScarlet fluorescent protein in the blood plasma using fiber photometry. An acidification response to anxiety was observed. Photoactivation of archaerhopsin-T (ArchT), an optogenetic tool that acts as an outward proton pump, results in intracellular alkalinization. Photostimulation of LHb in astrocyte-specific ArchT-expressing mice resulted in dissipation of theta-band LFP oscillation in an anxiogenic environment and suppression of anxiety-like behavior. These findings provide evidence that LHb astrocytes modulate anxiety and may offer a new target for treatment of anxiety disorders.
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Affiliation(s)
- Wanqin Tan
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan
| | - Yoko Ikoma
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan
| | - Yusuke Takahashi
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan; Systems Bioinformatics, Graduate School of Information Sciences, Tohoku University, Sendai 980-8579 Japan
| | - Ayumu Konno
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi 371-8511, Gunma, Japan; Viral Vector Core, Gunma University Initiative for Advanced Research, Maebashi 371-8511, Gunma, Japan
| | - Hirokazu Hirai
- Department of Neurophysiology and Neural Repair, Gunma University Graduate School of Medicine, Maebashi 371-8511, Gunma, Japan; Viral Vector Core, Gunma University Initiative for Advanced Research, Maebashi 371-8511, Gunma, Japan
| | - Hajime Hirase
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark; Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Ko Matsui
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan.
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3
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Araki S, Onishi I, Ikoma Y, Matsui K. Astrocyte switch to the hyperactive mode. Glia 2024; 72:1418-1434. [PMID: 38591259 DOI: 10.1002/glia.24537] [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: 01/23/2024] [Revised: 03/29/2024] [Accepted: 03/31/2024] [Indexed: 04/10/2024]
Abstract
Increasing pieces of evidence have suggested that astrocyte function has a strong influence on neuronal activity and plasticity, both in physiological and pathophysiological situations. In epilepsy, astrocytes have been shown to respond to epileptic neuronal seizures; however, whether they can act as a trigger for seizures has not been determined. Here, using the copper implantation method, spontaneous neuronal hyperactivity episodes were reliably induced during the week following implantation. With near 24-h continuous recording for over 1 week of the local field potential with in vivo electrophysiology and astrocyte cytosolic Ca2+ with the fiber photometry method, spontaneous occurrences of seizure episodes were captured. Approximately 1 day after the implantation, isolated aberrant astrocyte Ca2+ events were often observed before they were accompanied by neuronal hyperactivity, suggesting the role of astrocytes in epileptogenesis. Within a single developed episode, astrocyte Ca2+ increase preceded the neuronal hyperactivity by ~20 s, suggesting that actions originating from astrocytes could be the trigger for the occurrence of epileptic seizures. Astrocyte-specific stimulation by channelrhodopsin-2 or deep-brain direct current stimulation was capable of inducing neuronal hyperactivity. Injection of an astrocyte-specific metabolic inhibitor, fluorocitrate, was able to significantly reduce the magnitude of spontaneously occurring neuronal hyperactivity. These results suggest that astrocytes have a role in triggering individual seizures and the reciprocal astrocyte-neuron interactions likely amplify and exacerbate seizures. Therefore, future epilepsy treatment could be targeted at astrocytes to achieve epilepsy control.
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Affiliation(s)
- Shun Araki
- Super-network Brain Physiology, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Ichinosuke Onishi
- Super-network Brain Physiology, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Yoko Ikoma
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Ko Matsui
- Super-network Brain Physiology, Graduate School of Medicine, Tohoku University, Sendai, Japan
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
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4
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Hara Y, Ichiraku A, Matsuda T, Sakane A, Sasaki T, Nagai T, Horikawa K. High-affinity tuning of single fluorescent protein-type indicators by flexible linker length optimization in topology mutant. Commun Biol 2024; 7:705. [PMID: 38851844 PMCID: PMC11162441 DOI: 10.1038/s42003-024-06394-0] [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: 05/17/2023] [Accepted: 05/29/2024] [Indexed: 06/10/2024] Open
Abstract
Genetically encoded Ca2+ indicators (GECIs) are versatile for live imaging of cellular activities. Besides the brightness and dynamic range of signal change of GECIs, Ca2+ affinity is another critical parameter for successful Ca2+ imaging, as the concentration range of Ca2+ dynamics differs from low nanomolar to sub-millimolar depending on the celltype and organism. However, ultrahigh-affinity GECIs, particularly the single fluorescent protein (1FP)-type, are lacking. Here, we report a simple strategy that increases Ca2+ affinity through the linker length optimization in topology mutants of existing 1FP-type GECIs. The resulting ultrahigh-affinity GECIs, CaMPARI-nano, BGECO-nano, and RCaMP-nano (Kd = 17-25 nM), enable unique biological applications, including the detection of low nanomolar Ca2+ dynamics, highlighting active signaling cells, and multi-functional imaging with other second messengers. The linker length optimization in topology mutants could be applied to other 1FP-type indicators of glutamate and potassium, rendering it a widely applicable technique for modulating indicator affinity.
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Affiliation(s)
- Yusuke Hara
- Department of Optical Imaging, Advanced Research Promotion Center, Tokushima University, 3-18-15 Kuramoto, Tokushima, Tokushima, 770-8503, Japan
| | - Aya Ichiraku
- Department of Optical Imaging, Advanced Research Promotion Center, Tokushima University, 3-18-15 Kuramoto, Tokushima, Tokushima, 770-8503, Japan
| | - Tomoki Matsuda
- Department of Biomolecular Science and Engineering, SANKEN, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, 567-0047, Japan
| | - Ayuko Sakane
- Department of Biochemistry, Tokushima University Graduate School of Medicine, 3-18-15 Kuramoto, Tokushima, Tokushima, 770-8503, Japan
- Division of Interdisciplinary Researches for Medicine and Photonics, Institute of Post-LED Photonics (pLED), Tokushima University, 3-18-15 Kuramoto, Tokushima, Tokushima, 770-8503, Japan
| | - Takuya Sasaki
- Department of Biochemistry, Tokushima University Graduate School of Medicine, 3-18-15 Kuramoto, Tokushima, Tokushima, 770-8503, Japan
| | - Takeharu Nagai
- Department of Biomolecular Science and Engineering, SANKEN, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka, 567-0047, Japan
- Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Yamadaoka 2-1, Suita, Osaka, 565-0871, Japan
| | - Kazuki Horikawa
- Department of Optical Imaging, Advanced Research Promotion Center, Tokushima University, 3-18-15 Kuramoto, Tokushima, Tokushima, 770-8503, Japan.
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Tripathi U, Rosh I, Ben Ezer R, Nayak R, Hussein Y, Choudhary A, Djamus J, Manole A, Houlden H, Gage FH, Stern S. Upregulated ECM genes and increased synaptic activity in Parkinson's human DA neurons with PINK1/ PRKN mutations. NPJ Parkinsons Dis 2024; 10:103. [PMID: 38762512 PMCID: PMC11102563 DOI: 10.1038/s41531-024-00715-0] [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: 01/08/2023] [Accepted: 04/25/2024] [Indexed: 05/20/2024] Open
Abstract
Parkinson's disease (PD) is the second most prevalent neurodegenerative disease. Primary symptoms of PD arise with the loss of dopaminergic (DA) neurons in the Substantia Nigra Pars Compacta, but PD also affects the hippocampus and cortex, usually in its later stage. Approximately 15% of PD cases are familial with a genetic mutation. Two of the most associated genes with autosomal recessive (AR) early-onset familial PD are PINK1 and PRKN. In vitro studies of these genetic mutations are needed to understand the neurophysiological changes in patients' neurons that may contribute to neurodegeneration. In this work, we generated and differentiated DA and hippocampal neurons from human induced pluripotent stem cells (hiPSCs) derived from two patients with a double mutation in their PINK1 and PRKN (one homozygous and one heterozygous) genes and assessed their neurophysiology compared to two healthy controls. We showed that the synaptic activity of PD neurons generated from patients with the PINK1 and PRKN mutations is impaired in the hippocampus and dopaminergic neurons. Mutant dopaminergic neurons had enhanced excitatory post-synaptic activity. In addition, DA neurons with the homozygous mutation of PINK1 exhibited more pronounced electrophysiological differences compared to the control neurons. Signaling network analysis of RNA sequencing results revealed that Focal adhesion and ECM receptor pathway were the top two upregulated pathways in the mutant PD neurons. Our findings reveal that the phenotypes linked to PINK1 and PRKN mutations differ from those from other PD mutations, suggesting a unique interplay between these two mutations that drives different PD mechanisms.
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Affiliation(s)
- Utkarsh Tripathi
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Idan Rosh
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Ran Ben Ezer
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Ritu Nayak
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Yara Hussein
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Ashwani Choudhary
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Jose Djamus
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Andreea Manole
- Laboratory of Genetics, Gage, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Henry Houlden
- UCL queen square institute of neurology, University College London, London, England
| | - Fred H Gage
- Laboratory of Genetics, Gage, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Shani Stern
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.
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Asano Y, Sasaki D, Ikoma Y, Matsui K. Glial tone of aggression. Neurosci Res 2024; 202:39-51. [PMID: 38007191 DOI: 10.1016/j.neures.2023.11.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/16/2023] [Accepted: 11/20/2023] [Indexed: 11/27/2023]
Abstract
Anger transition is often abrupt. In this study, we investigated the mechanisms responsible for switching and modulating aggression levels. The cerebellum is considered a center for motor coordination and learning; however, its connection to social behavior has long been observed. Here, we used the resident-intruder paradigm in male mice and examined local field potential (LFP) changes, glial cytosolic ion fluctuations, and vascular dynamics in the cerebellar vermis throughout various phases of a combat sequence. Notably, we observed the emergence of theta band oscillations in the LFP and sustained elevations in glial Ca2+ levels during combat breakups. When astrocytes, including Bergmann glial cells, were photoactivated using channelrhodopsin-2, the theta band emerged and an early combat breakup occurred. Within a single combat sequence, rapid alteration of offensive (fight) and passive (flight) responses were observed, which roughly correlated with decreases and increases in glial Ca2+, respectively. Neuron-glial interactions in the cerebellar vermis may play a role in adjusting Purkinje cell excitability and setting the tone of aggression. Future anger management strategies and clinical control of excessive aggression and violent behavior may be realized by developing a therapeutic strategy that adjusts glial activity in the cerebellum.
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Affiliation(s)
- Yuki Asano
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan
| | - Daichi Sasaki
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan
| | - Yoko Ikoma
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan
| | - Ko Matsui
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577 Japan.
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7
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Sasaki D, Imai K, Ikoma Y, Matsui K. Plastic vasomotion entrainment. eLife 2024; 13:RP93721. [PMID: 38629828 PMCID: PMC11023696 DOI: 10.7554/elife.93721] [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] [Indexed: 04/19/2024] Open
Abstract
The presence of global synchronization of vasomotion induced by oscillating visual stimuli was identified in the mouse brain. Endogenous autofluorescence was used and the vessel 'shadow' was quantified to evaluate the magnitude of the frequency-locked vasomotion. This method allows vasomotion to be easily quantified in non-transgenic wild-type mice using either the wide-field macro-zoom microscopy or the deep-brain fiber photometry methods. Vertical stripes horizontally oscillating at a low temporal frequency (0.25 Hz) were presented to the awake mouse, and oscillatory vasomotion locked to the temporal frequency of the visual stimulation was induced not only in the primary visual cortex but across a wide surface area of the cortex and the cerebellum. The visually induced vasomotion adapted to a wide range of stimulation parameters. Repeated trials of the visual stimulus presentations resulted in the plastic entrainment of vasomotion. Horizontally oscillating visual stimulus is known to induce horizontal optokinetic response (HOKR). The amplitude of the eye movement is known to increase with repeated training sessions, and the flocculus region of the cerebellum is known to be essential for this learning to occur. Here, we show a strong correlation between the average HOKR performance gain and the vasomotion entrainment magnitude in the cerebellar flocculus. Therefore, the plasticity of vasomotion and neuronal circuits appeared to occur in parallel. Efficient energy delivery by the entrained vasomotion may contribute to meeting the energy demand for increased coordinated neuronal activity and the subsequent neuronal circuit reorganization.
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Affiliation(s)
- Daichi Sasaki
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku UniversitySendaiJapan
| | - Ken Imai
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku UniversitySendaiJapan
| | - Yoko Ikoma
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku UniversitySendaiJapan
| | - Ko Matsui
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku UniversitySendaiJapan
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Crapart CC, Scott ZC, Konno T, Sharma A, Parutto P, Bailey DMD, Westrate LM, Avezov E, Koslover EF. Luminal transport through intact endoplasmic reticulum limits the magnitude of localized Ca 2+ signals. Proc Natl Acad Sci U S A 2024; 121:e2312172121. [PMID: 38502705 PMCID: PMC10990089 DOI: 10.1073/pnas.2312172121] [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: 07/17/2023] [Accepted: 02/09/2024] [Indexed: 03/21/2024] Open
Abstract
The endoplasmic reticulum (ER) forms an interconnected network of tubules stretching throughout the cell. Understanding how ER functionality relies on its structural organization is crucial for elucidating cellular vulnerability to ER perturbations, which have been implicated in several neuronal pathologies. One of the key functions of the ER is enabling Ca[Formula: see text] signaling by storing large quantities of this ion and releasing it into the cytoplasm in a spatiotemporally controlled manner. Through a combination of physical modeling and live-cell imaging, we demonstrate that alterations in ER shape significantly impact its ability to support efficient local Ca[Formula: see text] releases, due to hindered transport of luminal content within the ER. Our model reveals that rapid Ca[Formula: see text] release necessitates mobile luminal buffer proteins with moderate binding strength, moving through a well-connected network of ER tubules. These findings provide insight into the functional advantages of normal ER architecture, emphasizing its importance as a kinetically efficient intracellular Ca[Formula: see text] delivery system.
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Affiliation(s)
- Cécile C. Crapart
- UK Dementia Research Institute at the University of Cambridge, CambridgeCB2 0AH, United Kingdom
- Department of Clinical Neurosciences, School of Clinical Medicine, The University of Cambridge, CambridgeCB2 0AH, United Kingdom
| | | | - Tasuku Konno
- UK Dementia Research Institute at the University of Cambridge, CambridgeCB2 0AH, United Kingdom
- Department of Clinical Neurosciences, School of Clinical Medicine, The University of Cambridge, CambridgeCB2 0AH, United Kingdom
| | - Aman Sharma
- Department of Physics, University of California, San Diego, La Jolla, CA92130
| | - Pierre Parutto
- UK Dementia Research Institute at the University of Cambridge, CambridgeCB2 0AH, United Kingdom
- Department of Clinical Neurosciences, School of Clinical Medicine, The University of Cambridge, CambridgeCB2 0AH, United Kingdom
| | - David M. D. Bailey
- UK Dementia Research Institute at the University of Cambridge, CambridgeCB2 0AH, United Kingdom
- Department of Clinical Neurosciences, School of Clinical Medicine, The University of Cambridge, CambridgeCB2 0AH, United Kingdom
| | - Laura M. Westrate
- Department of Chemistry and Biochemistry, Calvin University, Grand Rapids, MI49546
| | - Edward Avezov
- UK Dementia Research Institute at the University of Cambridge, CambridgeCB2 0AH, United Kingdom
- Department of Clinical Neurosciences, School of Clinical Medicine, The University of Cambridge, CambridgeCB2 0AH, United Kingdom
| | - Elena F. Koslover
- Department of Physics, University of California, San Diego, La Jolla, CA92130
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Rivera-Villaseñor A, Higinio-Rodríguez F, López-Hidalgo M. Astrocytes in Pain Perception: A Systems Neuroscience Approach. ADVANCES IN NEUROBIOLOGY 2024; 39:193-212. [PMID: 39190076 DOI: 10.1007/978-3-031-64839-7_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/28/2024]
Abstract
Astrocytes play an active role in the function of the brain integrating neuronal activity and regulating back neuronal dynamic. They have recently emerged as active contributors of brain's emergent properties such as perceptions. Here, we analyzed the role of astrocytes in pain perception from the lens of systems neuroscience, and we do this by analyzing how astrocytes encode nociceptive information within brain processing areas and how they are key regulators of the internal state that determines pain perception. Specifically, we discuss the dynamic interactions between astrocytes and neuromodulators, such as noradrenaline, highlighting their role in shaping the level of activation of the neuronal ensemble, thereby influencing the experience of pain. Also, we will discuss the possible implications of an "Astro-NeuroMatrix" in the integration of pain across sensory, affective, and cognitive dimensions of pain perception.
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Affiliation(s)
- Angélica Rivera-Villaseñor
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Queretaro, Qro., Mexico
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Queretaro, Qro., Mexico
| | - Frida Higinio-Rodríguez
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Queretaro, Qro., Mexico
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Queretaro, Qro., Mexico
| | - Mónica López-Hidalgo
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Queretaro, Qro., Mexico.
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Mukai Y, Okubo TS, Lazarus M, Ono D, Tanaka KF, Yamanaka A. Prostaglandin E 2 Induces Long-Lasting Inhibition of Noradrenergic Neurons in the Locus Coeruleus and Moderates the Behavioral Response to Stressors. J Neurosci 2023; 43:7982-7999. [PMID: 37734949 PMCID: PMC10669809 DOI: 10.1523/jneurosci.0353-23.2023] [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: 02/26/2023] [Revised: 09/11/2023] [Accepted: 09/14/2023] [Indexed: 09/23/2023] Open
Abstract
Neuronal activity is modulated not only by inputs from other neurons but also by various factors, such as bioactive substances. Noradrenergic (NA) neurons in the locus coeruleus (LC-NA neurons) are involved in diverse physiological functions, including sleep/wakefulness and stress responses. Previous studies have identified various substances and receptors that modulate LC-NA neuronal activity through techniques including electrophysiology, calcium imaging, and single-cell RNA sequencing. However, many substances with unknown physiological significance have been overlooked. Here, we established an efficient screening method for identifying substances that modulate LC-NA neuronal activity through intracellular calcium ([Ca2+]i) imaging using brain slices. Using both sexes of mice, we screened 53 bioactive substances, and identified five novel substances: gastrin-releasing peptide, neuromedin U, and angiotensin II, which increase [Ca2+]i, and pancreatic polypeptide and prostaglandin D2, which decrease [Ca2+]i Among them, neuromedin U induced the greatest response in female mice. In terms of the duration of [Ca2+]i change, we focused on prostaglandin E2 (PGE2), since it induces a long-lasting decrease in [Ca2+]i via the EP3 receptor. Conditional knock-out of the receptor in LC-NA neurons resulted in increased depression-like behavior, prolonged wakefulness in the dark period, and increased [Ca2+]i after stress exposure. Our results demonstrate the effectiveness of our screening method for identifying substances that modulate a specific neuronal population in an unbiased manner and suggest that stress-induced prostaglandin E2 can suppress LC-NA neuronal activity to moderate the behavioral response to stressors. Our screening method will contribute to uncovering previously unknown physiological functions of uncharacterized bioactive substances in specific neuronal populations.SIGNIFICANCE STATEMENT Bioactive substances modulate the activity of specific neuronal populations. However, since only a limited number of substances with predicted effects have been investigated, many substances that may modulate neuronal activity have gone unrecognized. Here, we established an unbiased method for identifying modulatory substances by measuring the intracellular calcium signal, which reflects neuronal activity. We examined noradrenergic (NA) neurons in the locus coeruleus (LC-NA neurons), which are involved in diverse physiological functions. We identified five novel substances that modulate LC-NA neuronal activity. We also found that stress-induced prostaglandin E2 (PGE2) may suppress LC-NA neuronal activity and influence behavioral outcomes. Our screening method will help uncover previously overlooked functions of bioactive substances and provide insight into unrecognized roles of specific neuronal populations.
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Affiliation(s)
- Yasutaka Mukai
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Aichi 464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Tatsuo S Okubo
- Chinese Institute for Brain Research, Beijing 102206, China
| | - Michael Lazarus
- International Institute for Integrative Sleep Medicine (WPI-IIIS) and Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Daisuke Ono
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Aichi 464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
| | - Kenji F Tanaka
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku, Tokyo 160-8582, Japan
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Aichi 464-8601, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan
- Chinese Institute for Brain Research, Beijing 102206, China
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku, Tokyo 160-8582, Japan
- National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan
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11
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Lia A, Di Spiezio A, Vitalini L, Tore M, Puja G, Losi G. Ion Channels and Ionotropic Receptors in Astrocytes: Physiological Functions and Alterations in Alzheimer's Disease and Glioblastoma. Life (Basel) 2023; 13:2038. [PMID: 37895420 PMCID: PMC10608464 DOI: 10.3390/life13102038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 10/03/2023] [Accepted: 10/07/2023] [Indexed: 10/29/2023] Open
Abstract
The human brain is composed of nearly one hundred billion neurons and an equal number of glial cells, including macroglia, i.e., astrocytes and oligodendrocytes, and microglia, the resident immune cells of the brain. In the last few decades, compelling evidence has revealed that glial cells are far more active and complex than previously thought. In particular, astrocytes, the most abundant glial cell population, not only take part in brain development, metabolism, and defense against pathogens and insults, but they also affect sensory, motor, and cognitive functions by constantly modulating synaptic activity. Not surprisingly, astrocytes are actively involved in neurodegenerative diseases (NDs) and other neurological disorders like brain tumors, in which they rapidly become reactive and mediate neuroinflammation. Reactive astrocytes acquire or lose specific functions that differently modulate disease progression and symptoms, including cognitive impairments. Astrocytes express several types of ion channels, including K+, Na+, and Ca2+ channels, transient receptor potential channels (TRP), aquaporins, mechanoreceptors, and anion channels, whose properties and functions are only partially understood, particularly in small processes that contact synapses. In addition, astrocytes express ionotropic receptors for several neurotransmitters. Here, we provide an extensive and up-to-date review of the roles of ion channels and ionotropic receptors in astrocyte physiology and pathology. As examples of two different brain pathologies, we focus on Alzheimer's disease (AD), one of the most diffuse neurodegenerative disorders, and glioblastoma (GBM), the most common brain tumor. Understanding how ion channels and ionotropic receptors in astrocytes participate in NDs and tumors is necessary for developing new therapeutic tools for these increasingly common neurological conditions.
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Affiliation(s)
- Annamaria Lia
- Department Biomedical Science, University of Padova, 35131 Padova, Italy; (A.L.); (A.D.S.)
| | - Alessandro Di Spiezio
- Department Biomedical Science, University of Padova, 35131 Padova, Italy; (A.L.); (A.D.S.)
- Neuroscience Institute (CNR-IN), Padova Section, 35131 Padova, Italy
| | - Lorenzo Vitalini
- Department Life Science, University of Modena and Reggio Emilia, 41125 Modena, Italy; (L.V.); (G.P.)
| | - Manuela Tore
- Institute of Nanoscience (CNR-NANO), Modena Section, 41125 Modena, Italy;
- Department Biomedical Science, Metabolic and Neuroscience, University of Modena and Reggio Emilia, 41125 Modena, Italy
| | - Giulia Puja
- Department Life Science, University of Modena and Reggio Emilia, 41125 Modena, Italy; (L.V.); (G.P.)
| | - Gabriele Losi
- Institute of Nanoscience (CNR-NANO), Modena Section, 41125 Modena, Italy;
- Department Biomedical Science, Metabolic and Neuroscience, University of Modena and Reggio Emilia, 41125 Modena, Italy
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12
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Katada Y, Kunimi H, Serizawa N, Lee D, Kobayashi K, Negishi K, Okano H, Tanaka KF, Tsubota K, Kurihara T. Starburst amacrine cells amplify optogenetic visual restoration through gap junctions. Mol Ther Methods Clin Dev 2023; 30:1-13. [PMID: 37324975 PMCID: PMC10265492 DOI: 10.1016/j.omtm.2023.05.011] [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: 07/22/2022] [Accepted: 05/09/2023] [Indexed: 06/17/2023]
Abstract
Ectopic induction of optogenetic actuators, such as channelrhodopsin, is a promising approach to restoring vision in the degenerating retina. However, the cell type-specific response of ectopic photoreception has not been well understood. There are limits to obtaining efficient gene expression in a specifically targeted cell population by a transgenic approach. In the present study, we established a murine model with high efficiency of gene induction to retinal ganglion cells (RGCs) and amacrine cells using an improved tetracycline transactivator-operator bipartite system (KENGE-tet system). To investigate the cell type-specific visual restorative effect, we expressed the channelrhodopsin gene into RGCs and amacrine cells using the KENGE-tet system. As a result, enhancement in the visual restorative effect was observed to RGCs and starburst amacrine cells. In conclusion, a photoresponse from amacrine cells may enhance the maintained response of RGCs and further increase or improve the visual restorative effect.
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Affiliation(s)
- Yusaku Katada
- Laboratory of Photobiology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Hiromitsu Kunimi
- Laboratory of Photobiology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Naho Serizawa
- Laboratory of Photobiology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Nutritional Sciences, Toyo University, Kita-ku, Tokyo 115-8650, Japan
| | - Deokho Lee
- Laboratory of Photobiology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan
| | - Kazuno Negishi
- Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Kenji F. Tanaka
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Kazuo Tsubota
- Tsubota Laboratory, Inc, Shinjuku-ku, Tokyo 160-0016, Japan
| | - Toshihide Kurihara
- Laboratory of Photobiology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
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13
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Kono A, Shikano Y, Tanaka KF, Yamaura K, Tsutsui‐Kimura I. Inhibition of the dorsomedial striatal direct pathway is essential for the execution of action sequences. Neuropsychopharmacol Rep 2023; 43:414-424. [PMID: 37553985 PMCID: PMC10496086 DOI: 10.1002/npr2.12369] [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: 05/30/2023] [Revised: 07/13/2023] [Accepted: 07/23/2023] [Indexed: 08/10/2023] Open
Abstract
Contrary to the previous notion that the dorsomedial striatum (DMS) is crucial for acquiring new learning, accumulated evidence has suggested that the DMS also plays a role in the execution of already learned action sequences. Here, we examined how the direct and indirect pathways in the DMS regulate action sequences using a task that requires animals to press a lever consecutively. Cell-type-specific bulk Ca2+ recording revealed that the direct pathway was inhibited at the time of sequence execution. The sequence-related response was blunted in trials where the sequential behaviors were disrupted. Optogenetic activation at the sequence start caused distraction of action sequences without affecting motor function or memory of the task structure. By contrast with the direct pathway, the indirect pathway was slightly activated at the start of the sequence, but the optogenetic suppression of such sequence-related signaling did not impact the behaviors. These results suggest that the inhibition of the DMS direct pathway promotes sequence execution potentially by suppressing the formation of a new association.
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Affiliation(s)
- Anna Kono
- Division of Brain SciencesInstitute for Advanced Medical Research, Keio University School of MedicineTokyoJapan
- Division of Social Pharmacy, Center for Social Pharmacy and Pharmaceutical Care SciencesKeio University Faculty of PharmacyTokyoJapan
| | - Yu Shikano
- Division of Brain SciencesInstitute for Advanced Medical Research, Keio University School of MedicineTokyoJapan
| | - Kenji F. Tanaka
- Division of Brain SciencesInstitute for Advanced Medical Research, Keio University School of MedicineTokyoJapan
| | - Katsunori Yamaura
- Division of Social Pharmacy, Center for Social Pharmacy and Pharmaceutical Care SciencesKeio University Faculty of PharmacyTokyoJapan
| | - Iku Tsutsui‐Kimura
- Division of Brain SciencesInstitute for Advanced Medical Research, Keio University School of MedicineTokyoJapan
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14
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Kato T, Tanaka KF, Natsubori A. Dopamine Receptor Type 2-Expressing Medium Spiny Neurons in the Ventral Lateral Striatum Have a Non-REM Sleep-Induce Function. eNeuro 2023; 10:ENEURO.0327-23.2023. [PMID: 37704366 PMCID: PMC10540673 DOI: 10.1523/eneuro.0327-23.2023] [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: 08/28/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/15/2023] Open
Abstract
Dopamine receptor type 2-expressing medium spiny neurons (D2-MSNs) in the medial part of the ventral striatum (VS) induce non-REM (NREM) sleep from the wake state in animals. However, it is unclear whether D2-MSNs in the lateral part of the VS (VLS), which is anatomically and functionally different from the medial part of the VS, contribute to sleep-wake regulation. This study aims to clarify whether and how D2-MSNs in the VLS are involved in sleep-wake regulation. Our study found that specifically removing D2-MSNs in the VLS led to an increase in wakefulness time in mice during the dark phase using a diphtheria toxin-mediated cell ablation/dysfunction technique. D2-MSN ablation throughout the VS further increased dark phase wakefulness time. These findings suggest that VLS D2-MSNs may induce sleep during the dark phase with the medial part of the VS. Next, our fiber photometric recordings revealed that the population intracellular calcium (Ca2+) signal in the VLS D2-MSNs increased during the transition from wake to NREM sleep. The mean Ca2+ signal level of VLS D2-MSNs was higher during NREM and REM sleep than during the wake state, supporting their sleep-inducing role. Finally, optogenetic activation of the VLS D2-MSNs during the wake state always induced NREM sleep, demonstrating the causality of VLS D2-MSNs activity with sleep induction. Additionally, activation of the VLS D1-MSNs, counterparts of D2-MSNs, always induced wake from NREM sleep, indicating a wake-promoting role. In conclusion, VLS D2-MSNs could have an NREM sleep-inducing function in coordination with those in the medial VS.
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Affiliation(s)
- Tomonobu Kato
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
- Faculty of Science and Technology, Keio University, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Kenji F Tanaka
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Akiyo Natsubori
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-Ku, Tokyo 156-8506, Japan
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15
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Kelly P, Sanchez-Mico MV, Hou SS, Whiteman S, Russ A, Hudry E, Arbel-Ornath M, Greenberg SM, Bacskai BJ. Neuronally Derived Soluble Abeta Evokes Cell-Wide Astrocytic Calcium Dysregulation in Absence of Amyloid Plaques in Vivo. J Neurosci 2023; 43:4926-4940. [PMID: 37236808 PMCID: PMC10312057 DOI: 10.1523/jneurosci.1988-22.2023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 03/22/2023] [Accepted: 04/27/2023] [Indexed: 05/28/2023] Open
Abstract
The key pathologic entities driving the destruction of synaptic function and integrity during the evolution of Alzheimer's disease (AD) remain elusive. Astrocytes are structurally and functionally integrated within synaptic and vascular circuitry and use calcium-based physiology to modulate basal synaptic transmission, vascular dynamics, and neurovascular coupling, which are central to AD pathogenesis. We used high-resolution multiphoton imaging to quantify all endogenous calcium signaling arising spontaneously throughout astrocytic somata, primary processes, fine processes, and capillary endfeet in the brain of awake APP/PS1 transgenic mice (11 male and 6 female mice). Endogenous calcium signaling within capillary endfeet, while surprisingly as active as astrocytic fine processes, was reduced ∼50% in the brain of awake APP/PS1 mice. Cortical astrocytes, in the presence of amyloid plaques in awake APP/PS1 mice, had a cell-wide increase in intracellular calcium associated with an increased frequency, amplitude, and duration of spontaneous calcium signaling. The cell-wide astrocytic calcium dysregulation was not directly related to distance to amyloid plaques. We could re-create the cell-wide intracellular calcium dysregulation in the absence of amyloid plaques following acute exposure to neuronally derived soluble Abeta from Tg2576 transgenic mice, in the living brain of male C57/Bl6 mice. Our findings highlight a role for astrocytic calcium pathophysiology in soluble-Abeta mediated neurodegenerative processes in AD. Additionally, therapeutic strategies aiming to protect astrocytic calcium physiology from soluble Abeta-mediated toxicity may need to pharmacologically enhance calcium signaling within the hypoactive capillary endfeet while reducing the hyperactivity of spontaneous calcium signaling throughout the rest of the astrocyte.SIGNIFICANCE STATEMENT Astrocytic calcium signaling is functionally involved in central pathologic processes of Alzheimer's disease. We quantified endogenous calcium signaling arising spontaneously in the brain of awake APP/PS1 mice, as general anesthesia suppressed astrocytic calcium signaling. Cell-wide astrocytic calcium dysregulation was not related to distance to amyloid plaques but mediated in part by neuronally derived soluble Abeta, supporting a role for astrocytes in soluble-Abeta mediated neurodegeneration. Spontaneous calcium signaling is largely compartmentalized and capillary endfeet were as active as fine processes but hypoactive in the presence of amyloid plaques, while the rest of the astrocyte became hyperactive. The cell-wide calcium pathophysiology in astrocytes may require a combination therapeutic strategy for hypoactive endfeet and astrocytic hyperactivity.
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Affiliation(s)
- Patricia Kelly
- Massachusetts General Hospital/Harvard Medical School, Charlestown, Massachusetts 02129
| | - Maria V Sanchez-Mico
- Massachusetts General Hospital/Harvard Medical School, Charlestown, Massachusetts 02129
| | - Steven S Hou
- Massachusetts General Hospital/Harvard Medical School, Charlestown, Massachusetts 02129
| | - Sara Whiteman
- Massachusetts General Hospital/Harvard Medical School, Charlestown, Massachusetts 02129
| | - Alyssa Russ
- Massachusetts General Hospital/Harvard Medical School, Charlestown, Massachusetts 02129
| | - Eloise Hudry
- Massachusetts General Hospital/Harvard Medical School, Charlestown, Massachusetts 02129
| | - Michal Arbel-Ornath
- Massachusetts General Hospital/Harvard Medical School, Charlestown, Massachusetts 02129
| | - Steven M Greenberg
- Massachusetts General Hospital/Harvard Medical School, Charlestown, Massachusetts 02129
| | - Brian J Bacskai
- Massachusetts General Hospital/Harvard Medical School, Charlestown, Massachusetts 02129
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16
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Rasmussen RN, Asiminas A, Carlsen EMM, Kjaerby C, Smith NA. Astrocytes: integrators of arousal state and sensory context. Trends Neurosci 2023; 46:418-425. [PMID: 37003933 PMCID: PMC10192111 DOI: 10.1016/j.tins.2023.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/24/2023] [Accepted: 03/05/2023] [Indexed: 04/01/2023]
Abstract
The integration of external information with the internal state of the body is central to the survival of virtually every multicellular organism. However, a complete picture of the mechanisms that govern this process is lacking. In this opinion article, we synthesize evidence demonstrating that astrocytes sense the momentary arousal state - through neuromodulator release - as well as the sensory inputs - through local synaptic activity - and respond to them with changes in calcium (Ca2+) signaling. We hypothesize that astrocytes integrate sensory signals with the internal state and that this process is necessary to secure optimal behavior. Finally, we argue that dysfunctional astrocytic Ca2+ signaling could be an underlying factor in disorders characterized by disrupted sensory processing.
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Affiliation(s)
- Rune Nguyen Rasmussen
- Center for Translational Neuromedicine, University of Copenhagen, 2200 Copenhagen, Denmark.
| | - Antonis Asiminas
- Center for Translational Neuromedicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | | | - Celia Kjaerby
- Center for Translational Neuromedicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Nathan Anthony Smith
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, NY 14642, USA.
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17
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Ikoma Y, Sasaki D, Matsui K. Local brain environment changes associated with epileptogenesis. Brain 2023; 146:576-586. [PMID: 36423658 DOI: 10.1093/brain/awac355] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/30/2022] [Accepted: 09/08/2022] [Indexed: 11/27/2022] Open
Abstract
Plastic change of the neuronal system has traditionally been assumed to be governed primarily by the long-term potentiation/depression mechanisms of synaptic transmission. However, a rather simple shift in the ambient ion, transmitter and metabolite concentrations could have a pivotal role in generating plasticity upon the physiological process of learning and memory. Local brain environment and metabolic changes could also be the cause and consequences of the pathogenesis leading to epilepsy. Governing of the local brain environment is the primal function of astrocytes. The metabolic state of the entire brain is strongly linked to the activity of the lateral hypothalamus. In this study, plastic change of astrocyte reactions in the lateral hypothalamus was examined using epileptogenesis as an extreme form of plasticity. Fluorescent sensors for calcium or pH expressed in astrocytes were examined for up to one week by in vivo fibre photometry in freely moving transgenic male mice. Optical fluctuations on a timescale of seconds is difficult to assess because these signals are heavily influenced by local brain blood volume changes and pH changes. Using a newly devised method for the analysis of the optical signals, changes in Ca2+ and pH in astrocytes and changes in local brain blood volume associated with hippocampal-stimulated epileptic seizures were extracted. Following a transient alkaline shift in the astrocyte triggered by neuronal hyperactivity, a prominent acidic shift appeared in response to intensified seizure which developed with kindling. The acidic shift was unexpected as transient increase in local brain blood volume was observed in response to intensified seizures, which should lead to efficient extrusion of the acidic CO2. The acidic shift could be a result of glutamate transporter activity and/or due to the increased metabolic load of astrocytes leading to increased CO2 and lactate production. This acidic shift may trigger additional gliotransmitter release from astrocytes leading to the exacerbation of epilepsy. As all cellular enzymic reactions are influenced by Ca2+ and pH, changes in these parameters could also have an impact on the neuronal circuit activity. Thus, controlling the astrocyte pH and/or Ca2+ could be a new therapeutic target for treatment of epilepsy or prevention of undesired plasticity associated with epileptogenesis.
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Affiliation(s)
- Yoko Ikoma
- Super-network Brain Physiology Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Daichi Sasaki
- Super-network Brain Physiology Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
| | - Ko Matsui
- Super-network Brain Physiology Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.,Super-network Brain Physiology, Graduate School of Medicine, Tohoku University, Sendai 980-8577, Japan
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18
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Yang Z, Koslover EF. Diffusive exit rates through pores in membrane-enclosed structures. Phys Biol 2023; 20. [PMID: 36626849 DOI: 10.1088/1478-3975/acb1ea] [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: 10/27/2022] [Accepted: 01/10/2023] [Indexed: 01/11/2023]
Abstract
The function of many membrane-enclosed intracellular structures relies on release of diffusing particles that exit through narrow pores or channels in the membrane. The rate of release varies with pore size, density, and length of the channel. We propose a simple approximate model, validated with stochastic simulations, for estimating the effective release rate from cylinders, and other simple-shaped domains, as a function of channel parameters. The results demonstrate that, for very small pores, a low density of channels scattered over the boundary is sufficient to achieve substantial rates of particle release. Furthermore, we show that increasing the length of passive channels will both reduce release rates and lead to a less steep dependence on channel density. Our results are compared to previously-measured local calcium release rates from tubules of the endoplasmic reticulum, providing an estimate of the relevant channel density responsible for the observed calcium efflux.
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Affiliation(s)
- Zitao Yang
- La Jolla Country Day School, La Jolla, CA 92037, United States of America
| | - Elena F Koslover
- Department of Physics, University of California, San Diego, La Jolla, CA 92093, United States of America
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19
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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: 17] [Impact Index Per Article: 17.0] [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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20
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Natsubori A, Miyazawa M, Kojima T, Honda M. Region-specific involvement of ventral striatal dopamine D2 receptor-expressing medium spiny neurons in nociception. Neurosci Res 2022; 191:48-56. [PMID: 36549387 DOI: 10.1016/j.neures.2022.12.008] [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: 08/29/2022] [Revised: 12/08/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
The ventrolateral striatum (VLS), a subregion of the ventral striatum (VS), possesses distinct neuronal Ca2+ activities and functions in reward-oriented behavior, compared with the ventromedial striatum (VMS) based on the anatomical feature. We hypothesized that the VLS exhibits unique neuronal activity and function in nociceptive processing, a part of aversive processing. Using fiber photometry to monitor the neuronal Ca2+ activities, we demonstrated that acute noxious mechanical stimuli like tail-pinch increased the Ca2+ activity of dopamine D2 receptor-expressing medium spiny neurons (D2-MSNs) in the VLS in correlation with the stimulus intensities in mice, whereas mechanical stimuli increased the VMS D2-MSN activity independent of the stimulus intensities. Likewise, thermal stimuli decreased the VLS and VMS D2-MSN Ca2+ activities during nociceptive behaviors in the hot plate test. Furthermore, the VLS D2-MSNs increased their Ca2+ activity accompanied by formalin-induced nociceptive behaviors in mice, whereas the VMS D2-MSNs decreased it. The optogenetic inhibition of VLS D2-MSN activity increased the formalin-induced pain-related behavior in mice, thus suggesting the inhibitory effect of VLS D2-MSN activity on chemical nociceptive behavior, in contrast to previous reports that the VMS D2-MSNs could not involve the behavior. Therefore, the VLS D2-MSNs exhibited region-specific roles in nociception.
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Affiliation(s)
- Akiyo Natsubori
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
| | - Momoka Miyazawa
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan; Faculty of Science Division Ⅱ, Tokyo University of Science, 1-3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Takashi Kojima
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Makoto Honda
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
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21
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Li J, Feng P, Zhao L, Chen J, Du M, Song J, Wu Y. Transition behavior of the seizure dynamics modulated by the astrocyte inositol triphosphate noise. CHAOS (WOODBURY, N.Y.) 2022; 32:113121. [PMID: 36456345 DOI: 10.1063/5.0124123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 10/17/2022] [Indexed: 06/17/2023]
Abstract
Epilepsy is a neurological disorder with recurrent seizures, which convey complex dynamical characteristics including chaos and randomness. Until now, the underlying mechanism has not been fully elucidated, especially the bistable property beneath the epileptic random induction phenomena in certain conditions. Inspired by the recent finding that astrocyte GTPase-activating protein (G-protein)-coupled receptors could be involved in stochastic epileptic seizures, we proposed a neuron-astrocyte network model, incorporating the noise of the astrocytic second messenger, inositol triphosphate (IP3) that is modulated by G-protein-coupled receptor activation. Based on this model, we have statistically analyzed the transitions of epileptic seizures by performing repeatable simulation trials. Our simulation results show that the increase in the IP3 noise intensity induces depolarization-block epileptic seizures together with an increase in neuronal firing frequency, consistent with corresponding experiments. Meanwhile, the bistable states of the seizure dynamics were present under certain noise intensities, during which the neuronal firing pattern switches between regular sparse spiking and epileptic seizure states. This random presence of epileptic seizures is absent when the noise intensity continues to increase, accompanying with an increase in the epileptic depolarization block duration. The simulation results also shed light on the fact that calcium signals in astrocytes play significant roles in the pattern formations of the epileptic seizure. Our results provide a potential pathway for understanding the epileptic randomness in certain conditions.
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Affiliation(s)
- Jiajia Li
- College of Information and Control Engineering, Xi'an University of Architecture and Technology, Shaanxi, Xi'an 710055, China
| | - Peihua Feng
- State Key Laboratory for Strength and Vibration of Mechanical Structures, National Demonstration Center for Experimental Mechanics Education, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Liang Zhao
- College of Information and Control Engineering, Xi'an University of Architecture and Technology, Shaanxi, Xi'an 710055, China
| | - Junying Chen
- College of Information and Control Engineering, Xi'an University of Architecture and Technology, Shaanxi, Xi'an 710055, China
| | - Mengmeng Du
- School of Mathematics and Data Science, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Jian Song
- Department of Neurosurgery, Wuhan General Hospital of PLA, Wuhan 430070, China
| | - Ying Wu
- State Key Laboratory for Strength and Vibration of Mechanical Structures, National Demonstration Center for Experimental Mechanics Education, School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China
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22
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Ding F, Liang S, Li R, Yang Z, He Y, Yang S, Duan Q, Zhang J, Lyu J, Zhou Z, Huang M, Wang H, Li J, Yang C, Wang Y, Gong M, Chen S, Jia H, Chen X, Liao X, Fu L, Zhang K. Astrocytes exhibit diverse Ca2+ changes at subcellular domains during brain aging. Front Aging Neurosci 2022; 14:1029533. [PMID: 36389078 PMCID: PMC9650392 DOI: 10.3389/fnagi.2022.1029533] [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: 08/27/2022] [Accepted: 10/11/2022] [Indexed: 11/23/2022] Open
Abstract
Astrocytic Ca2+ transients are essential for astrocyte integration into neural circuits. These Ca2+ transients are primarily sequestered in subcellular domains, including primary branches, branchlets and leaflets, and endfeet. In previous studies, it suggests that aging causes functional defects in astrocytes. Until now, it was unclear whether and how aging affects astrocytic Ca2+ transients at subcellular domains. In this study, we combined a genetically encoded Ca2+ sensor (GCaMP6f) and in vivo two-photon Ca2+ imaging to determine changes in Ca2+ transients within astrocytic subcellular domains during brain aging. We showed that aging increased Ca2+ transients in astrocytic primary branches, higher-order branchlets, and terminal leaflets. However, Ca2+ transients decreased within astrocytic endfeet during brain aging, which could be caused by the decreased expressions of Aquaporin-4 (AQP4). In addition, aging-induced changes of Ca2+ transient types were heterogeneous within astrocytic subcellular domains. These results demonstrate that the astrocytic Ca2+ transients within subcellular domains are affected by aging differently. This finding contributes to a better understanding of the physiological role of astrocytes in aging-induced neural circuit degeneration.
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Affiliation(s)
- Fusheng Ding
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Shanshan Liang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Ruijie Li
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
- Advanced Institute for Brain and Intelligence and School of Physical Science and Technology, Guangxi University, Nanning, China
| | - Zhiqi Yang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Yong He
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Shaofan Yang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Qingtian Duan
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Jianxiong Zhang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Jing Lyu
- Brain Research Instrument Innovation Center, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
| | - Zhenqiao Zhou
- Brain Research Instrument Innovation Center, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
| | - Mingzhu Huang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Haoyu Wang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Jin Li
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Chuanyan Yang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Yuxia Wang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Mingyue Gong
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
| | - Shangbin Chen
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Hongbo Jia
- Advanced Institute for Brain and Intelligence and School of Physical Science and Technology, Guangxi University, Nanning, China
- Brain Research Instrument Innovation Center, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, China
- Combinatorial NeuroImaging Core Facility, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Xiaowei Chen
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
- Guangyang Bay Laboratory, Chongqing Institute for Brain and Intelligence, Chongqing, China
| | - Xiang Liao
- Center for Neurointelligence, School of Medicine, Chongqing University, Chongqing, China
- *Correspondence: Xiang Liao,
| | - Ling Fu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China
- MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
- Ling Fu,
| | - Kuan Zhang
- Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China
- Kuan Zhang,
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23
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Cholesterol-induced robust Ca oscillation in astrocytes required for survival and lipid droplet formation in high-cholesterol condition. iScience 2022; 25:105138. [PMID: 36185358 PMCID: PMC9523397 DOI: 10.1016/j.isci.2022.105138] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 08/08/2022] [Accepted: 09/10/2022] [Indexed: 11/22/2022] Open
Abstract
Cholesterol, one of the major cell membrane components, stabilizes membrane fluidity and regulates signal transduction. Beside its canonical roles, cholesterol has been reported to directly activate signaling pathways such as hedgehog (Hh). We recently found that astrocytes, one of the glial cells, respond to Hh pathway stimulation by Ca signaling. These notions led us to test if extracellularly applied cholesterol triggers Ca signaling in astrocytes. Here, we found that cholesterol application induces robust Ca oscillation only in astrocytes with different properties from the Hh-induced Ca response. The Ca oscillation has a long delay which corresponds to the onset of cholesterol accumulation in the plasma membrane. Blockade of the Ca oscillation resulted in enhancement of astrocytic cell death and disturbance of lipid droplet formation, implying a possibility that the cholesterol-induced Ca oscillation plays important roles in astrocytic survival and cholesterol handling under pathological conditions of cholesterol load such as demyelination. Robust Ca oscillation by cholesterol in astrocytes but not in neurons and microglia Cholesterol-induced Ca oscillation relates to membrane cholesterol accumulation The Ca oscillation is driven via the PLC-IP3 signaling pathway Ca oscillation inhibition leads to astrocytic death and lipid droplet malformation
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24
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Rahaman SM, Chowdhury S, Mukai Y, Ono D, Yamaguchi H, Yamanaka A. Functional Interaction Between GABAergic Neurons in the Ventral Tegmental Area and Serotonergic Neurons in the Dorsal Raphe Nucleus. Front Neurosci 2022; 16:877054. [PMID: 35663550 PMCID: PMC9160575 DOI: 10.3389/fnins.2022.877054] [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: 02/16/2022] [Accepted: 04/21/2022] [Indexed: 12/02/2022] Open
Abstract
GABAergic neurons in the ventral tegmental area (VTA) have brain-wide projections and are involved in multiple behavioral and physiological functions. Here, we revealed the responsiveness of Gad67+ neurons in VTA (VTAGad67+) to various neurotransmitters involved in the regulation of sleep/wakefulness by slice patch clamp recording. Among the substances tested, a cholinergic agonist activated, but serotonin, dopamine and histamine inhibited these neurons. Dense VTAGad67+ neuronal projections were observed in brain areas regulating sleep/wakefulness, including the central amygdala (CeA), dorsal raphe nucleus (DRN), and locus coeruleus (LC). Using a combination of electrophysiology and optogenetic studies, we showed that VTAGad67+ neurons inhibited all neurons recorded in the DRN, but did not inhibit randomly recorded neurons in the CeA and LC. Further examination revealed that the serotonergic neurons in the DRN (DRN5–HT) were monosynaptically innervated and inhibited by VTAGad67+ neurons. All recorded DRN5–HT neurons received inhibitory input from VTAGad67+ neurons, while only one quarter of them received inhibitory input from local GABAergic neurons. Gad67+ neurons in the DRN (DRNGad67+) also received monosynaptic inhibitory input from VTAGad67+ neurons. Taken together, we found that VTAGad67+ neurons were integrated in many inputs, and their output inhibits DRN5–HT neurons, which may regulate physiological functions including sleep/wakefulness.
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Affiliation(s)
- Sheikh Mizanur Rahaman
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Srikanta Chowdhury
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, United States
| | - Yasutaka Mukai
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Daisuke Ono
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiroshi Yamaguchi
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
- Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, Japan
- *Correspondence: Akihiro Yamanaka,
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25
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Huffels CFM, Osborn LM, Cappaert NLM, Hol EM. Calcium signaling in individual APP/PS1 mouse dentate gyrus astrocytes increases ex vivo with Aβ pathology and age without affecting astrocyte network activity. J Neurosci Res 2022; 100:1281-1295. [PMID: 35293016 PMCID: PMC9314019 DOI: 10.1002/jnr.25042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 01/12/2022] [Accepted: 02/22/2022] [Indexed: 01/24/2023]
Abstract
Astrocytes are critical for healthy brain function. In Alzheimer's disease, astrocytes become reactive, which affects their signaling properties. Here, we measured spontaneous calcium transients ex vivo in hippocampal astrocytes in brain slices containing the dentate gyrus of 6- (6M) and 9-month-old (9M) APPswe/PSEN1dE9 (APP/PS1) mice. We investigated the frequency and duration of calcium transients in relation to aging, amyloid-β (Aβ) pathology, and the proximity of the astrocyte to Aβ plaques. The 6M APP/PS1 astrocytes showed no change in spontaneous calcium-transient properties compared to wild-type (WT) astrocytes. 9M APP/PS1 astrocytes, however, showed more hyperactivity compared to WT, characterized by increased spontaneous calcium transients that were longer in duration. Our data also revealed an effect of aging, as 9M astrocytes overall showed an increase in calcium activity compared to 6M astrocytes. Subsequent calcium-wave analysis showed an increase in sequential calcium transients (i.e., calcium waves) in 9M astrocytes, suggesting increased network activity ex vivo. Further analysis using null models revealed that this network effect is caused by chance, due to the increased number of spontaneous transients. Our findings show that alterations in calcium signaling in individual hippocampal astrocytes of APP/PS1 mice are subject to both aging and Aβ pathology but these do not lead to a change in astrocyte network activity. These alterations in calcium dynamics of astrocytes may help to understand changes in neuronal physiology leading to cognitive decline and ultimately dementia.
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Affiliation(s)
- Christiaan F M Huffels
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Lana M Osborn
- Swammerdam Institute for Life Sciences, Center for Neuroscience, Cellular and Computational Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Natalie L M Cappaert
- Swammerdam Institute for Life Sciences, Center for Neuroscience, Cellular and Computational Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
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26
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Danjo Y, Shinozaki Y, Natsubori A, Kubota Y, Kashiwagi K, Tanaka KF, Koizumi S. The Mlc1 Promoter Directs Müller Cell-specific Gene Expression in the Retina. Transl Vis Sci Technol 2022; 11:25. [PMID: 35040915 PMCID: PMC8764212 DOI: 10.1167/tvst.11.1.25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Because the importance of glia in regulating brain functions has been demonstrated, genetic technologies that manipulate glial cell-specific gene expression in the brain have become essential and have made great progress. However, it is unknown whether the same strategy that is used in the brain can be applied to the retina because retinal glia differs from glia in the brain. Here, we aimed to find a method for selective gene expression in Müller cells (characteristic glial cells in the retina) and identified Mlc1 as a specific promoter of Müller cells. Methods Mlc1-tTA::Yellow-Cameleon-NanotetO/tetO (YC-Nano) mice were used as a reporter line. YC-Nano, a fluorescent protein, was ectopically expressed in the cell type controlled by the Mlc1 promotor. Immunofluorescence staining was used to identify the cell type expressing YC-Nano protein. Results YC-Nano-positive (+) signals were observed as vertical stalks in the sliced retina and spanned from the nerve fiber layer through the outer nuclear layer. The density of YC-Nano+ cells was higher around the optic nerve head and lower in the peripheral retina. The YC-Nano+ signals colocalized with vimentin, a marker of Müller cells, but not with the cell markers for blood vessels, microglia, neurons, or astrocytes. Conclusions The Mlc1 promoter allows us to manipulate gene expression in Müller cells without affecting astrocytes in the retina. Translational Relevance Gene manipulation under control of Mlc1 promoter offers novel technique to investigate the role of Müller cells.
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Affiliation(s)
- Yosuke Danjo
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Youichi Shinozaki
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Akiyo Natsubori
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yuto Kubota
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Kenji Kashiwagi
- Department of Ophthalmology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan.,GLIA Center, University of Yamanashi, Yamanashi, Japan
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27
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Abdelaal MS, Midorikawa M, Suzuki T, Kobayashi K, Takata N, Miyata M, Mimura M, Tanaka KF. OUP accepted manuscript. Brain Commun 2022; 4:fcac010. [PMID: 35243344 PMCID: PMC8887905 DOI: 10.1093/braincomms/fcac010] [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: 10/27/2021] [Revised: 11/02/2021] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
Spike-and-wave discharges and an accompanying loss of consciousness are hallmarks of absence seizure, which is a childhood generalized epilepsy disorder. In absence seizure, dysfunction of the cortico-thalamo-cortico circuitry is thought to engage in abnormal cortical rhythms. Previous studies demonstrated that the thalamic reticular nucleus has a critical role in the formation of normal cortical rhythms; however, whether thalamic reticular nucleus dysfunction leads directly to abnormal rhythms, such as epilepsy, is largely unknown. We found that expressing the inhibitory opsin, archaerhodopsin, including in the thalamic reticular nucleus, caused abnormal cortical rhythms in Pvalb-tetracycline transactivator::tetO-ArchT (PV-ArchT) double transgenic mice. We validated the PV-ArchT line as a new mouse model of absence seizure through physiological and pharmacological analyses, as well as through examining their behavioural features. We then discovered that archaerhodopsin expression exclusively in thalamic reticular nucleus parvalbumin-positive neurons was sufficient to induce cortical spike-and-wave discharges using adeno-associated virus-mediated thalamic reticular nucleus targeting. Furthermore, we found that archaerhodopsin expression impaired rebound burst firing and T-current in thalamic reticular nucleus parvalbumin-positive cells by slice physiology. Although T-current in the thalamic reticular nucleus was impaired, the T-current blocker ethosuximide still had a therapeutic effect in PV-ArchT mice, suggesting a gain of function of T-type calcium channels in this absence seizure model. However, we did not find any over- or misexpression of T-type calcium channel genes in the thalamus or the cortex. Thus, we demonstrated that thalamic reticular nucleus dysfunction led to an absence seizure-like phenotype in mice. In a final set of experiments, we showed that the archaerhodopsin-mediated absence seizure-like phenotype disappeared after the removal of archaerhodopsin by using a time-controllable transgenic system. These data may provide a hint as to why many absence seizures naturally regress.
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Affiliation(s)
- Manal S. Abdelaal
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Mitsuharu Midorikawa
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women’s Medical University, Tokyo 162-8666, Japan
| | - Toru Suzuki
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Norio Takata
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Mariko Miyata
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women’s Medical University, Tokyo 162-8666, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kenji F. Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo 160-8582, Japan
- Correspondence to: Kenji F. Tanaka, MD, PhD Division of Brain Sciences, Institute for Advanced Medical Research Keio University School of Medicine 35 Shinanomachi Shinjuku-ku Tokyo 160-8582, Japan E-mail:
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28
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A human iPSC-astroglia neurodevelopmental model reveals divergent transcriptomic patterns in schizophrenia. Transl Psychiatry 2021; 11:554. [PMID: 34716291 PMCID: PMC8556332 DOI: 10.1038/s41398-021-01681-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 09/20/2021] [Accepted: 10/01/2021] [Indexed: 12/17/2022] Open
Abstract
While neurodevelopmental abnormalities have been associated with schizophrenia (SCZ), the role of astroglia in disease pathophysiology remains poorly understood. In the present study, we used a human induced pluripotent stem cell (iPSC)-derived astrocyte model to investigate the temporal patterns of astroglia differentiation during developmental stages critical for SCZ using RNA sequencing. The model generated astrocyte-specific gene expression patterns during differentiation that corresponded well to astroglia-specific expression signatures of in vivo cortical fetal development. Using this model we identified SCZ-specific expression dynamics, and found that SCZ-associated differentially expressed genes were significantly enriched in the medial prefrontal cortex, striatum, and temporal lobe, targeting VWA5A and ADAMTS19. In addition, SCZ astrocytes displayed alterations in calcium signaling, and significantly decreased glutamate uptake and metalloproteinase activity relative to controls. These results implicate novel transcriptional dynamics in astrocyte differentiation in SCZ together with functional changes that are potentially important biological components of SCZ pathology.
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29
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Arizono M, Nägerl UV. Deciphering the functional nano-anatomy of the tripartite synapse using stimulated emission depletion microscopy. Glia 2021; 70:607-618. [PMID: 34664734 DOI: 10.1002/glia.24103] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 09/24/2021] [Accepted: 09/30/2021] [Indexed: 11/12/2022]
Abstract
A major challenge for studying neuron-astrocyte communication lies in visualizing the tripartite synapse, which is the physical site where astrocytic processes contact and interact with neuronal synapses. While conventional light microscopy cannot resolve the anatomical details of the tripartite synapse, electron microscopy only provides ultrastructural snapshots that tell us little about its living state and dynamics. Stimulated emission depletion (STED) microscopy is a super-resolution fluorescence imaging technique that can provide live images of tripartite synapses with nanoscale spatial resolution. It is compatible with physiology experiments and imaging in the intact brain in vivo, opening up new opportunities to link the nanoscale structure of the tripartite system with functional readouts of neurons and astrocytes or even behavior. In this review, we first summarize the findings and insights from previous studies addressing the structure-function relationship of the tripartite synapse using conventional imaging techniques. We then explain the basic principle of STED microscopy and the main challenges facing its application to live-tissue imaging of fine astrocytic processes. We summarize insights from our recent STED studies, which revealed new aspects of the structure and physiology of the tripartite synapse and the surrounding extracellular space. Finally, we discuss how the STED approach and other advanced optical techniques can illuminate the role of astrocytes for brain physiology and animal behavior.
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Affiliation(s)
- Misa Arizono
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, CNRS UMR, Bordeaux, France
| | - U Valentin Nägerl
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France.,Interdisciplinary Institute for Neuroscience, CNRS UMR, Bordeaux, France
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30
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Liu X, Ying J, Wang X, Zheng Q, Zhao T, Yoon S, Yu W, Yang D, Fang Y, Hua F. Astrocytes in Neural Circuits: Key Factors in Synaptic Regulation and Potential Targets for Neurodevelopmental Disorders. Front Mol Neurosci 2021; 14:729273. [PMID: 34658786 PMCID: PMC8515196 DOI: 10.3389/fnmol.2021.729273] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 09/02/2021] [Indexed: 12/14/2022] Open
Abstract
Astrocytes are the major glial cells in the brain, which play a supporting role in the energy and nutritional supply of neurons. They were initially regarded as passive space-filling cells, but the latest progress in the study of the development and function of astrocytes highlights their active roles in regulating synaptic transmission, formation, and plasticity. In the concept of "tripartite synapse," the bidirectional influence between astrocytes and neurons, in addition to their steady-state and supporting function, suggests that any negative changes in the structure or function of astrocytes will affect the activity of neurons, leading to neurodevelopmental disorders. The role of astrocytes in the pathophysiology of various neurological and psychiatric disorders caused by synaptic defects is increasingly appreciated. Understanding the roles of astrocytes in regulating synaptic development and the plasticity of neural circuits could help provide new treatments for these diseases.
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Affiliation(s)
- Xing Liu
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Jun Ying
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Xifeng Wang
- Department of Anesthesiology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Qingcui Zheng
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Tiancheng Zhao
- Mailman School of Public Health, Columbia University, New York, NY, United States
| | - Sungtae Yoon
- Helping Minds International Charitable Foundation, New York, NY, United States
| | - Wen Yu
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Danying Yang
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Yang Fang
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
| | - Fuzhou Hua
- Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang, China
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31
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Weiss S, Clamon LC, Manoim JE, Ormerod KG, Parnas M, Littleton JT. Glial ER and GAP junction mediated Ca 2+ waves are crucial to maintain normal brain excitability. Glia 2021; 70:123-144. [PMID: 34528727 DOI: 10.1002/glia.24092] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 08/29/2021] [Accepted: 08/30/2021] [Indexed: 11/08/2022]
Abstract
Astrocytes play key roles in regulating multiple aspects of neuronal function from invertebrates to humans and display Ca2+ fluctuations that are heterogeneously distributed throughout different cellular microdomains. Changes in Ca2+ dynamics represent a key mechanism for how astrocytes modulate neuronal activity. An unresolved issue is the origin and contribution of specific glial Ca2+ signaling components at distinct astrocytic domains to neuronal physiology and brain function. The Drosophila model system offers a simple nervous system that is highly amenable to cell-specific genetic manipulations to characterize the role of glial Ca2+ signaling. Here we identify a role for ER store-operated Ca2+ entry (SOCE) pathway in perineurial glia (PG), a glial population that contributes to the Drosophila blood-brain barrier. We show that PG cells display diverse Ca2+ activity that varies based on their locale within the brain. Ca2+ signaling in PG cells does not require extracellular Ca2+ and is blocked by inhibition of SOCE, Ryanodine receptors, or gap junctions. Disruption of these components triggers stimuli-induced seizure-like episodes. These findings indicate that Ca2+ release from internal stores and its propagation between neighboring glial cells via gap junctions are essential for maintaining normal nervous system function.
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Affiliation(s)
- Shirley Weiss
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Lauren C Clamon
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Julia E Manoim
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Kiel G Ormerod
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Moshe Parnas
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - J Troy Littleton
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.,Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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32
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Chronic social defeat stress impairs goal-directed behavior through dysregulation of ventral hippocampal activity in male mice. Neuropsychopharmacology 2021; 46:1606-1616. [PMID: 33692477 PMCID: PMC8280175 DOI: 10.1038/s41386-021-00990-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/30/2021] [Accepted: 02/20/2021] [Indexed: 12/12/2022]
Abstract
Chronic stress is a risk factor for a variety of psychiatric disorders, including depression. Although impairments to motivated behavior are a major symptom of clinical depression, little is known about the circuit mechanisms through which stress impairs motivation. Furthermore, research in animal models for depression has focused on impairments to hedonic aspects of motivation, whereas patient studies suggest that impairments to appetitive, goal-directed motivation contribute significantly to motivational impairments in depression. Here, we characterized goal-directed motivation in repeated social defeat stress (R-SDS), a well-established mouse model for depression in male mice. R-SDS impaired the ability to sustain and complete goal-directed behavior in a food-seeking operant lever-press task. Furthermore, stress-exposed mice segregated into susceptible and resilient subpopulations. Interestingly, susceptibility to stress-induced motivational impairments was unrelated to stress-induced social withdrawal, another prominent effect of R-SDS in mouse models. Based on evidence that ventral hippocampus (vHP) modulates sustainment of goal-directed behavior, we monitored vHP activity during the task using fiber photometry. Successful task completion was associated with suppression of ventral hippocampal neural activity. This suppression was diminished after R-SDS in stress-susceptible but not stress-resilient mice. The serotonin selective reuptake inhibitor (SSRI) escitalopram and ketamine both normalized vHP activity during the task and restored motivated behavior. Furthermore, optogenetic vHP inhibition was sufficient to restore motivated behavior after stress. These results identify vHP hyperactivity as a circuit mechanism of stress-induced impairments to goal-directed behavior and a putative biomarker that is sensitive to antidepressant treatments and that differentiates susceptible and resilient individuals.
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Sherwood MW, Arizono M, Panatier A, Mikoshiba K, Oliet SHR. Astrocytic IP 3Rs: Beyond IP 3R2. Front Cell Neurosci 2021; 15:695817. [PMID: 34393726 PMCID: PMC8363081 DOI: 10.3389/fncel.2021.695817] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/30/2021] [Indexed: 12/31/2022] Open
Abstract
Astrocytes are sensitive to ongoing neuronal/network activities and, accordingly, regulate neuronal functions (synaptic transmission, synaptic plasticity, behavior, etc.) by the context-dependent release of several gliotransmitters (e.g., glutamate, glycine, D-serine, ATP). To sense diverse input, astrocytes express a plethora of G-protein coupled receptors, which couple, via Gi/o and Gq, to the intracellular Ca2+ release channel IP3-receptor (IP3R). Indeed, manipulating astrocytic IP3R-Ca2+ signaling is highly consequential at the network and behavioral level: Depleting IP3R subtype 2 (IP3R2) results in reduced GPCR-Ca2+ signaling and impaired synaptic plasticity; enhancing IP3R-Ca2+ signaling affects cognitive functions such as learning and memory, sleep, and mood. However, as a result of discrepancies in the literature, the role of GPCR-IP3R-Ca2+ signaling, especially under physiological conditions, remains inconclusive. One primary reason for this could be that IP3R2 has been used to represent all astrocytic IP3Rs, including IP3R1 and IP3R3. Indeed, IP3R1 and IP3R3 are unique Ca2+ channels in their own right; they have unique biophysical properties, often display distinct distribution, and are differentially regulated. As a result, they mediate different physiological roles to IP3R2. Thus, these additional channels promise to enrich the diversity of spatiotemporal Ca2+ dynamics and provide unique opportunities for integrating neuronal input and modulating astrocyte–neuron communication. The current review weighs evidence supporting the existence of multiple astrocytic-IP3R isoforms, summarizes distinct sub-type specific properties that shape spatiotemporal Ca2+ dynamics. We also discuss existing experimental tools and future refinements to better recapitulate the endogenous activities of each IP3R isoform.
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Affiliation(s)
- Mark W Sherwood
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, Bordeaux, France
| | - Misa Arizono
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Aude Panatier
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, Bordeaux, France
| | - Katsuhiko Mikoshiba
- ShanghaiTech University, Shanghai, China.,Faculty of Science, Toho University, Funabashi, Japan.,RIKEN CLST, Kobe, Japan
| | - Stéphane H R Oliet
- University of Bordeaux, INSERM, Neurocentre Magendie, U1215, Bordeaux, France
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34
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Abe Y, Kwon S, Oishi M, Unekawa M, Takata N, Seki F, Koyama R, Abe M, Sakimura K, Masamoto K, Tomita Y, Okano H, Mushiake H, Tanaka KF. Optical manipulation of local cerebral blood flow in the deep brain of freely moving mice. Cell Rep 2021; 36:109427. [PMID: 34320360 DOI: 10.1016/j.celrep.2021.109427] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/07/2021] [Accepted: 06/29/2021] [Indexed: 11/18/2022] Open
Abstract
An artificial tool for manipulating local cerebral blood flow (CBF) is necessary for understanding how CBF controls brain function. Here, we generate vascular optogenetic tools whereby smooth muscle cells and endothelial cells express optical actuators in the brain. The illumination of channelrhodopsin-2 (ChR2)-expressing mice induces a local reduction in CBF. Photoactivated adenylyl cyclase (PAC) is an optical protein that increases intracellular cyclic adenosine monophosphate (cAMP), and the illumination of PAC-expressing mice induces a local increase in CBF. We target the ventral striatum, determine the temporal kinetics of CBF change, and optimize the illumination intensity to confine the effects to the ventral striatum. We demonstrate the utility of this vascular optogenetic manipulation in freely and adaptively behaving mice and validate the task- and actuator-dependent behavioral readouts. The development of vascular optogenetic animal models will help accelerate research linking vasculature, circuits, and behavior to health and disease.
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Affiliation(s)
- Yoshifumi Abe
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan; Live Imaging Center, Central Institute for Experimental Animals, Kawasaki 210-0821, Japan
| | - Soojin Kwon
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan; Department of Physiology, Tohoku University School of Medicine, Sendai 980-8575, Japan
| | - Mitsuhiro Oishi
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Miyuki Unekawa
- Department of Neurology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Norio Takata
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan; Live Imaging Center, Central Institute for Experimental Animals, Kawasaki 210-0821, Japan
| | - Fumiko Seki
- Live Imaging Center, Central Institute for Experimental Animals, Kawasaki 210-0821, Japan; Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Ryuta Koyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Kenji Sakimura
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Kazuto Masamoto
- Brain Science Inspired Life Support Research Center, University of Electro-Communications, Tokyo 182-8585, Japan
| | - Yutaka Tomita
- Department of Neurology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Hideyuki Okano
- Live Imaging Center, Central Institute for Experimental Animals, Kawasaki 210-0821, Japan; Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan; Laboratory for Marmoset Neural Architecture, RIKEN Center for Brain Science, Saitama 351-0198, Japan
| | - Hajime Mushiake
- Department of Physiology, Tohoku University School of Medicine, Sendai 980-8575, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan.
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35
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Tsunematsu T, Sakata S, Sanagi T, Tanaka KF, Matsui K. Region-Specific and State-Dependent Astrocyte Ca 2+ Dynamics during the Sleep-Wake Cycle in Mice. J Neurosci 2021; 41:5440-5452. [PMID: 34006590 PMCID: PMC8221592 DOI: 10.1523/jneurosci.2912-20.2021] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 04/06/2021] [Accepted: 05/02/2021] [Indexed: 11/21/2022] Open
Abstract
Neural activity is diverse, and varies depending on brain regions and sleep/wakefulness states. However, whether astrocyte activity differs between sleep/wakefulness states, and whether there are differences in astrocyte activity among brain regions remain poorly understood. Therefore, in this study, we recorded astrocyte intracellular calcium (Ca2+) concentrations of mice during sleep/wakefulness states in the cortex, hippocampus, hypothalamus, cerebellum, and pons using fiber photometry. For this purpose, male transgenic mice expressing the genetically encoded ratiometric Ca2+ sensor YCnano50 specifically in their astrocytes were used. We demonstrated that Ca2+ levels in astrocytes substantially decrease during rapid eye movement (REM) sleep, and increase after the onset of wakefulness. In contrast, differences in Ca2+ levels during non-REM (NREM) sleep were observed among the different brain regions, and no significant decrease was observed in the hypothalamus and pons. Further analyses focusing on the transition between sleep/wakefulness states and correlation analysis with the duration of REM sleep showed that Ca2+ dynamics differs among brain regions, suggesting the existence of several clusters, i.e., the first comprising the cortex and hippocampus, the second comprising the hypothalamus and pons, and the third comprising the cerebellum. Our study thus demonstrated that astrocyte Ca2+ levels change substantially according to sleep/wakefulness states. These changes were consistent in general unlike neural activity. However, we also clarified that Ca2+ dynamics varies depending on the brain region, implying that astrocytes may play various physiological roles in sleep.SIGNIFICANCE STATEMENT Sleep is an instinctive behavior of many organisms. In the previous five decades, the mechanism of the neural circuits controlling sleep/wakefulness states and the neural activities associated with sleep/wakefulness states in various brain regions have been elucidated. However, whether astrocytes, which are a type of glial cell, change their activity during different sleep/wakefulness states was poorly understood. Here, we demonstrated that dynamic changes in astrocyte Ca2+ concentrations occur in the cortex, hippocampus, hypothalamus, cerebellum, and pons of mice during natural sleep. Further analyses demonstrated that Ca2+ dynamics slightly differ among different brain regions, implying that the physiological roles of astrocytes in sleep/wakefulness might vary depending on the brain region.
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Affiliation(s)
- Tomomi Tsunematsu
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
- Advanced Interdisciplinary Research Division, Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan
| | - Shuzo Sakata
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, United Kingdom
| | - Tomomi Sanagi
- Advanced Interdisciplinary Research Division, Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Ko Matsui
- Super-network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan
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36
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Lohr C, Beiersdorfer A, Fischer T, Hirnet D, Rotermund N, Sauer J, Schulz K, Gee CE. Using Genetically Encoded Calcium Indicators to Study Astrocyte Physiology: A Field Guide. Front Cell Neurosci 2021; 15:690147. [PMID: 34177468 PMCID: PMC8226001 DOI: 10.3389/fncel.2021.690147] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/06/2021] [Indexed: 01/14/2023] Open
Abstract
Ca2+ imaging is the most frequently used technique to study glial cell physiology. While chemical Ca2+ indicators served to visualize and measure changes in glial cell cytosolic Ca2+ concentration for several decades, genetically encoded Ca2+ indicators (GECIs) have become state of the art in recent years. Great improvements have been made since the development of the first GECI and a large number of GECIs with different physical properties exist, rendering it difficult to select the optimal Ca2+ indicator. This review discusses some of the most frequently used GECIs and their suitability for glial cell research.
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Affiliation(s)
- Christian Lohr
- Division of Neurophysiology, University of Hamburg, Hamburg, Germany
| | | | - Timo Fischer
- Division of Neurophysiology, University of Hamburg, Hamburg, Germany
| | - Daniela Hirnet
- Division of Neurophysiology, University of Hamburg, Hamburg, Germany
| | - Natalie Rotermund
- Division of Neurophysiology, University of Hamburg, Hamburg, Germany
| | - Jessica Sauer
- Division of Neurophysiology, University of Hamburg, Hamburg, Germany
| | - Kristina Schulz
- Division of Neurophysiology, University of Hamburg, Hamburg, Germany
| | - Christine E Gee
- Institute of Synaptic Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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37
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Lia A, Henriques VJ, Zonta M, Chiavegato A, Carmignoto G, Gómez-Gonzalo M, Losi G. Calcium Signals in Astrocyte Microdomains, a Decade of Great Advances. Front Cell Neurosci 2021; 15:673433. [PMID: 34163329 PMCID: PMC8216559 DOI: 10.3389/fncel.2021.673433] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/23/2021] [Indexed: 12/13/2022] Open
Abstract
The glial cells astrocytes have long been recognized as important neuron-supporting elements in brain development, homeostasis, and metabolism. After the discovery that the reciprocal communication between astrocytes and neurons is a fundamental mechanism in the modulation of neuronal synaptic communication, over the last two decades astrocytes became a hot topic in neuroscience research. Crucial to their functional interactions with neurons are the cytosolic Ca2+ elevations that mediate gliotransmission. Large attention has been posed to the so-called Ca2+microdomains, dynamic Ca2+ changes spatially restricted to fine astrocytic processes including perisynaptic astrocytic processes (PAPs). With presynaptic terminals and postsynaptic neuronal membranes, PAPs compose the tripartite synapse. The distinct spatial-temporal features and functional roles of astrocyte microdomain Ca2+ activity remain poorly defined. However, thanks to the development of genetically encoded Ca2+ indicators (GECIs), advanced microscopy techniques, and innovative analytical approaches, Ca2+ transients in astrocyte microdomains were recently studied in unprecedented detail. These events have been observed to occur much more frequently (∼50–100-fold) and dynamically than somatic Ca2+ elevations with mechanisms that likely involve both IP3-dependent and -independent pathways. Further progress aimed to clarify the complex, dynamic machinery responsible for astrocytic Ca2+ activity at microdomains is a crucial step in our understanding of the astrocyte role in brain function and may also reveal astrocytes as novel therapeutic targets for different brain diseases. Here, we review the most recent studies that improve our mechanistic understanding of the essential features of astrocyte Ca2+ microdomains.
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Affiliation(s)
- Annamaria Lia
- Neuroscience Institute, National Research Council (IN-CNR), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Vanessa Jorge Henriques
- Neuroscience Institute, National Research Council (IN-CNR), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Micaela Zonta
- Neuroscience Institute, National Research Council (IN-CNR), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Angela Chiavegato
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Giorgio Carmignoto
- Neuroscience Institute, National Research Council (IN-CNR), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Marta Gómez-Gonzalo
- Neuroscience Institute, National Research Council (IN-CNR), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Gabriele Losi
- Neuroscience Institute, National Research Council (IN-CNR), Padua, Italy.,Department of Biomedical Sciences, University of Padua, Padua, Italy
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38
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McNeill J, Rudyk C, Hildebrand ME, Salmaso N. Ion Channels and Electrophysiological Properties of Astrocytes: Implications for Emergent Stimulation Technologies. Front Cell Neurosci 2021; 15:644126. [PMID: 34093129 PMCID: PMC8173131 DOI: 10.3389/fncel.2021.644126] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 04/26/2021] [Indexed: 12/12/2022] Open
Abstract
Astrocytes comprise a heterogeneous cell population characterized by distinct morphologies, protein expression and function. Unlike neurons, astrocytes do not generate action potentials, however, they are electrically dynamic cells with extensive electrophysiological heterogeneity and diversity. Astrocytes are hyperpolarized cells with low membrane resistance. They are heavily involved in the modulation of K+ and express an array of different voltage-dependent and voltage-independent channels to help with this ion regulation. In addition to these K+ channels, astrocytes also express several different types of Na+ channels; intracellular Na+ signaling in astrocytes has been linked to some of their functional properties. The physiological hallmark of astrocytes is their extensive intracellular Ca2+ signaling cascades, which vary at the regional, subregional, and cellular levels. In this review article, we highlight the physiological properties of astrocytes and the implications for their function and influence of network and synaptic activity. Furthermore, we discuss the implications of these differences in the context of optogenetic and DREADD experiments and consider whether these tools represent physiologically relevant techniques for the interrogation of astrocyte function.
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Affiliation(s)
- Jessica McNeill
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | | | | | - Natalina Salmaso
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
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39
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Abstract
Astrocytes play a key role in brain homeostasis and functions such as memory. Specifically, astrocytes express multiple receptors that transduce signals via the second messenger cAMP. However, the involvement of astrocytic cAMP in animal behavior and the underlying glial-neuronal interactions remains largely unknown. Here, we show that an increase in astrocytic cAMP is sufficient to induce synaptic plasticity and modulate memory. We developed a method to increase astrocytic cAMP levels in vivo using photoactivated adenylyl cyclase and found that increased cAMP in hippocampal astrocytes at different time points facilitated memory formation but interrupted memory retention via NMDA receptor-dependent plasticity. Furthermore, we found that the cAMP-induced modulation of memory was mediated by the astrocyte-neuron lactate shuttle. Thus, our study unveils a role of astrocytic cAMP in brain function by providing a tool to modulate astrocytic cAMP in vivo.
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40
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Izawa S, Yoneshiro T, Kondoh K, Nakagiri S, Okamatsu-Ogura Y, Terao A, Minokoshi Y, Yamanaka A, Kimura K. Melanin-concentrating hormone-producing neurons in the hypothalamus regulate brown adipose tissue and thus contribute to energy expenditure. J Physiol 2021; 600:815-827. [PMID: 33899241 DOI: 10.1113/jp281241] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 04/20/2021] [Indexed: 12/17/2022] Open
Abstract
KEY POINTS Melanin-concentrating hormone (MCH) neuron-ablated mice exhibit increased energy expenditure and reduced fat weight. Increased brown adipose tissue (BAT) activity and locomotor activity-independent energy expenditure contributed to body weight reduction in MCH neuron-ablated mice. MCH neurons send inhibitory input to the medullary raphe nucleus to modulate BAT activity. ABSTRACT Hypothalamic melanin-concentrating hormone (MCH) peptide robustly affects energy homeostasis. However, it is unclear whether and how MCH-producing neurons, which contain and release a variety of neuropeptides/transmitters, regulate energy expenditure in the central nervous system and peripheral tissues. We thus examined the regulation of energy expenditure by MCH neurons, focusing on interscapular brown adipose tissue (BAT) activity. MCH neuron-ablated mice exhibited reduced body weight, increased oxygen consumption, and increased BAT activity, which improved locomotor activity-independent energy expenditure. Trans-neuronal retrograde tracing with the recombinant pseudorabies virus revealed that MCH neurons innervate BAT via the sympathetic premotor region in the medullary raphe nucleus (MRN). MRN neurons were activated by MCH neuron ablation. Therefore, endogenous MCH neuron activity negatively modulates energy expenditure via BAT inhibition. MRN neurons might receive inhibitory input from MCH neurons to suppress BAT activity.
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Affiliation(s)
- Shuntaro Izawa
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan.,Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, 464-8601, Japan.,Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.,JSPS Research Fellowship for Young Scientists, Tokyo, 102-0083, Japan
| | - Takeshi Yoneshiro
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan.,Division of Metabolic Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, 153-8904, Japan
| | - Kunio Kondoh
- Division of Endocrinology and Metabolism, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, 444-8585, Japan
| | - Shohei Nakagiri
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan
| | - Yuko Okamatsu-Ogura
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan
| | - Akira Terao
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan.,Department of Biology, School of Biological Sciences, Tokai University, Sapporo, 005-8601, Japan
| | - Yasuhiko Minokoshi
- Division of Endocrinology and Metabolism, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8585, Japan.,Department of Physiological Sciences, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, 444-8585, Japan
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, 464-8601, Japan.,Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Kazuhiro Kimura
- Laboratory of Biochemistry, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, 060-0818, Japan
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41
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Adrenergic inhibition facilitates normalization of extracellular potassium after cortical spreading depolarization. Sci Rep 2021; 11:8150. [PMID: 33854148 PMCID: PMC8047013 DOI: 10.1038/s41598-021-87609-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/31/2021] [Indexed: 01/31/2023] Open
Abstract
Cortical spreading depolarization (CSD) is a propagating wave of tissue depolarization characterized by a large increase of extracellular potassium concentration and prolonged subsequent electrical silencing of neurons. Waves of CSD arise spontaneously in various acute neurological settings, including migraine aura and ischemic stroke. Recently, we have reported that pan-inhibition of adrenergic receptors (AdRs) facilitates the normalization of extracellular potassium after acute photothrombotic stroke in mice. Here, we have extended that mechanistic study to ask whether AdR antagonists also modify the dynamics of KCl-induced CSD and post-CSD recovery in vivo. Spontaneous neural activity and KCl-induced CSD were visualized by cortex-wide transcranial Ca2+ imaging in G-CaMP7 transgenic mice. AdR antagonism decreased the recurrence of CSD waves and accelerated the post-CSD recovery of neural activity. Two-photon imaging revealed that astrocytes exhibited aberrant Ca2+ signaling after passage of the CSD wave. This astrocytic Ca2+ activity was diminished by the AdR antagonists. Furthermore, AdR pan-antagonism facilitated the normalization of the extracellular potassium level after CSD, which paralleled the recovery of neural activity. These observations add support to the proposal that neuroprotective effects of AdR pan-antagonism arise from accelerated normalization of extracellular K+ levels in the setting of acute brain injury.
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42
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Lim D, Semyanov A, Genazzani A, Verkhratsky A. Calcium signaling in neuroglia. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 362:1-53. [PMID: 34253292 DOI: 10.1016/bs.ircmb.2021.01.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glial cells exploit calcium (Ca2+) signals to perceive the information about the activity of the nervous tissue and the tissue environment to translate this information into an array of homeostatic, signaling and defensive reactions. Astrocytes, the best studied glial cells, use several Ca2+ signaling generation pathways that include Ca2+ entry through plasma membrane, release from endoplasmic reticulum (ER) and from mitochondria. Activation of metabotropic receptors on the plasma membrane of glial cells is coupled to an enzymatic cascade in which a second messenger, InsP3 is generated thus activating intracellular Ca2+ release channels in the ER endomembrane. Astrocytes also possess store-operated Ca2+ entry and express several ligand-gated Ca2+ channels. In vivo astrocytes generate heterogeneous Ca2+ signals, which are short and frequent in distal processes, but large and relatively rare in soma. In response to neuronal activity intracellular and inter-cellular astrocytic Ca2+ waves can be produced. Astrocytic Ca2+ signals are involved in secretion, they regulate ion transport across cell membranes, and are contributing to cell morphological plasticity. Therefore, astrocytic Ca2+ signals are linked to fundamental functions of the central nervous system ranging from synaptic transmission to behavior. In oligodendrocytes, Ca2+ signals are generated by plasmalemmal Ca2+ influx, or by release from intracellular stores, or by combination of both. Microglial cells exploit Ca2+ permeable ionotropic purinergic receptors and transient receptor potential channels as well as ER Ca2+ release. In this contribution, basic morphology of glial cells, glial Ca2+ signaling toolkit, intracellular Ca2+ signals and Ca2+-regulated functions are discussed with focus on astrocytes.
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Affiliation(s)
- Dmitry Lim
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Novara, Italy.
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia; Faculty of Biology, Moscow State University, Moscow, Russia; Sechenov First Moscow State Medical University, Moscow, Russia
| | - Armando Genazzani
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale, Novara, Italy
| | - Alexei Verkhratsky
- Sechenov First Moscow State Medical University, Moscow, Russia; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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43
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Fabbri R, Saracino E, Treossi E, Zamboni R, Palermo V, Benfenati V. Graphene glial-interfaces: challenges and perspectives. NANOSCALE 2021; 13:4390-4407. [PMID: 33599662 DOI: 10.1039/d0nr07824g] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Graphene nanosheets are mechanically strong but flexible, electrically conductive and bio-compatible. Thus, due to these unique properties, they are being intensively studied as materials for the next generation of neural interfaces. Most of the literature focused on optimizing the interface between these materials and neurons. However, one of the most common causes of implant failure is the adverse inflammatory reaction of glial cells. These cells are not, as previously considered, just passive and supportive cells, but play a crucial role in the physiology and pathology of the nervous system, and in the interaction with implanted electrodes. Besides providing structural support to neurons, glia are responsible for the modulation of synaptic transmission and control of central and peripheral homeostasis. Accordingly, knowledge on the interaction between glia and biomaterials is essential to develop new implant-based therapies for the treatment of neurological disorders, such as epilepsy, brain tumours, and Alzheimer's and Parkinson's disease. This work provides an overview of the emerging literature on the interaction of graphene-based materials with glial cells, together with a complete description of the different types of glial cells and problems associated with them. We believe that this description will be important for researchers working in materials science and nanotechnology to develop new active materials to interface, measure and stimulate these cells.
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Affiliation(s)
- Roberta Fabbri
- Consiglio Nazionale delle Ricerche, Istituto per la Sintesi Organica e la Fotoreattività (CNR-ISOF), via Piero Gobetti 101, 40129 Bologna, Italy.
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44
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Perez-Catalan NA, Doe CQ, Ackerman SD. The role of astrocyte-mediated plasticity in neural circuit development and function. Neural Dev 2021; 16:1. [PMID: 33413602 PMCID: PMC7789420 DOI: 10.1186/s13064-020-00151-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/26/2020] [Indexed: 02/03/2023] Open
Abstract
Neuronal networks are capable of undergoing rapid structural and functional changes called plasticity, which are essential for shaping circuit function during nervous system development. These changes range from short-term modifications on the order of milliseconds, to long-term rearrangement of neural architecture that could last for the lifetime of the organism. Neural plasticity is most prominent during development, yet also plays a critical role during memory formation, behavior, and disease. Therefore, it is essential to define and characterize the mechanisms underlying the onset, duration, and form of plasticity. Astrocytes, the most numerous glial cell type in the human nervous system, are integral elements of synapses and are components of a glial network that can coordinate neural activity at a circuit-wide level. Moreover, their arrival to the CNS during late embryogenesis correlates to the onset of sensory-evoked activity, making them an interesting target for circuit plasticity studies. Technological advancements in the last decade have uncovered astrocytes as prominent regulators of circuit assembly and function. Here, we provide a brief historical perspective on our understanding of astrocytes in the nervous system, and review the latest advances on the role of astroglia in regulating circuit plasticity and function during nervous system development and homeostasis.
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Affiliation(s)
- Nelson A Perez-Catalan
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, USA
- Kennedy Center, Department of Pediatrics, The University of Chicago, Chicago, IL, USA
| | - Chris Q Doe
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, USA
| | - Sarah D Ackerman
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR, USA.
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45
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Kosugi K, Yoshida K, Suzuki T, Kobayashi K, Yoshida K, Mimura M, Tanaka KF. Activation of ventral CA1 hippocampal neurons projecting to the lateral septum during feeding. Hippocampus 2020; 31:294-304. [PMID: 33296119 PMCID: PMC7984357 DOI: 10.1002/hipo.23289] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 11/24/2020] [Accepted: 11/27/2020] [Indexed: 01/20/2023]
Abstract
A number of studies have reported the involvement of the ventral hippocampus (vHip) and the lateral septum (LS) in negative emotional responses. Besides these well‐documented functions, they are also thought to control feeding behavior. In particular, optogenetic and pharmacogenetic interventions to LS‐projecting vHip neurons have demonstrated that the vHip→LS neural circuit exerts an inhibition on feeding behavior. However, there have been no reports of vHip neuronal activity during feeding. Here, we focused on LS‐projecting vCA1 neurons (vCA1→LS) and monitored their activity during feeding behaviors in mice. vCA1→LS neurons were retrogradely labeled with adeno‐associated virus carrying a ratiometric Ca2+ indicator and measured compound Ca2+ dynamics by fiber photometry. We first examined vCA1→LS activity in random food‐exploring behavior and found that vCA1→LS activation seemed to coincide with food intake; however, our ability to visually confirm this during freely moving behaviors was not sufficiently reliable. We next examined vCA1→LS activity in a goal‐directed, food‐seeking lever‐press task which temporally divided the mouse state into preparatory, effort, and consummatory phases. We observed vCA1→LS activation in the postprandial period during the consummatory phase. Such timing‐ and pathway‐specific activation was not observed from pan‐vCA1 neurons. In contrast, reward omission eliminated this activity, indicating that vCA1→LS activation is contingent on the food reward. Sated mice pressed the lever significantly fewer times but still ate food; however, vCA1→LS neurons were not activated, suggesting that vCA1→LS neurons did not respond to habitual behavior. Combined, these results suggest that gastrointestinal interoception rather than food‐intake motions or external sensations are likely to coincide with vCA1→LS activity. Accordingly, we propose that vCA1→LS neurons discriminate between matched or unmatched predictive bodily states in which incoming food will satisfy an appetite. We also demonstrate that vCA1→LS neurons are activated in aversive/anxious situations in an elevated plus maze and tail suspension test. Future behavioral tests utilizing anxious conflict and food intake may reconcile the multiple functions of vCA1→LS neurons.
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Affiliation(s)
- Kenzo Kosugi
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan
| | - Keitaro Yoshida
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Toru Suzuki
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki, Japan
| | - Kazunari Yoshida
- Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
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46
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Manninen T, Saudargiene A, Linne ML. Astrocyte-mediated spike-timing-dependent long-term depression modulates synaptic properties in the developing cortex. PLoS Comput Biol 2020; 16:e1008360. [PMID: 33170856 PMCID: PMC7654831 DOI: 10.1371/journal.pcbi.1008360] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 09/22/2020] [Indexed: 12/26/2022] Open
Abstract
Astrocytes have been shown to modulate synaptic transmission and plasticity in specific cortical synapses, but our understanding of the underlying molecular and cellular mechanisms remains limited. Here we present a new biophysicochemical model of a somatosensory cortical layer 4 to layer 2/3 synapse to study the role of astrocytes in spike-timing-dependent long-term depression (t-LTD) in vivo. By applying the synapse model and electrophysiological data recorded from rodent somatosensory cortex, we show that a signal from a postsynaptic neuron, orchestrated by endocannabinoids, astrocytic calcium signaling, and presynaptic N-methyl-D-aspartate receptors coupled with calcineurin signaling, induces t-LTD which is sensitive to the temporal difference between post- and presynaptic firing. We predict for the first time the dynamics of astrocyte-mediated molecular mechanisms underlying t-LTD and link complex biochemical networks at presynaptic, postsynaptic, and astrocytic sites to the time window of t-LTD induction. During t-LTD a single astrocyte acts as a delay factor for fast neuronal activity and integrates fast neuronal sensory processing with slow non-neuronal processing to modulate synaptic properties in the brain. Our results suggest that astrocytes play a critical role in synaptic computation during postnatal development and are of paramount importance in guiding the development of brain circuit functions, learning and memory.
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Affiliation(s)
- Tiina Manninen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
- Department of Neurobiology, Stanford University, Stanford, CA, USA
| | - Ausra Saudargiene
- Neuroscience Institute, Lithuanian University of Health Sciences, Kaunas, Lithuania
- Department of Informatics, Vytautas Magnus University, Kaunas, Lithuania
| | - Marja-Leena Linne
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
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Okubo Y. Astrocytic Ca2+ signaling mediated by the endoplasmic reticulum in health and disease. J Pharmacol Sci 2020; 144:83-88. [DOI: 10.1016/j.jphs.2020.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 12/19/2022] Open
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48
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Presa JL, Saravia F, Bagi Z, Filosa JA. Vasculo-Neuronal Coupling and Neurovascular Coupling at the Neurovascular Unit: Impact of Hypertension. Front Physiol 2020; 11:584135. [PMID: 33101063 PMCID: PMC7546852 DOI: 10.3389/fphys.2020.584135] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/04/2020] [Indexed: 12/18/2022] Open
Abstract
Components of the neurovascular unit (NVU) establish dynamic crosstalk that regulates cerebral blood flow and maintain brain homeostasis. Here, we describe accumulating evidence for cellular elements of the NVU contributing to critical physiological processes such as cerebral autoregulation, neurovascular coupling, and vasculo-neuronal coupling. We discuss how alterations in the cellular mechanisms governing NVU homeostasis can lead to pathological changes in which vascular endothelial and smooth muscle cell, pericyte and astrocyte function may play a key role. Because hypertension is a modifiable risk factor for stroke and accelerated cognitive decline in aging, we focus on hypertension-associated changes on cerebral arteriole function and structure, and the molecular mechanisms through which these may contribute to cognitive decline. We gather recent emerging evidence concerning cognitive loss in hypertension and the link with vascular dementia and Alzheimer’s disease. Collectively, we summarize how vascular dysfunction, chronic hypoperfusion, oxidative stress, and inflammatory processes can uncouple communication at the NVU impairing cerebral perfusion and contributing to neurodegeneration.
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Affiliation(s)
- Jessica L Presa
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - Flavia Saravia
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - Zsolt Bagi
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Jessica A Filosa
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
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49
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Verkhratsky A, Semyanov A, Zorec R. Physiology of Astroglial Excitability. FUNCTION (OXFORD, ENGLAND) 2020; 1:zqaa016. [PMID: 35330636 PMCID: PMC8788756 DOI: 10.1093/function/zqaa016] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 08/29/2020] [Accepted: 09/03/2020] [Indexed: 01/06/2023]
Abstract
Classic physiology divides all neural cells into excitable neurons and nonexcitable neuroglia. Neuroglial cells, chiefly responsible for homeostasis and defense of the nervous tissue, coordinate their complex homeostatic responses with neuronal activity. This coordination reflects a specific form of glial excitability mediated by complex changes in intracellular concentration of ions and second messengers organized in both space and time. Astrocytes are equipped with multiple molecular cascades, which are central for regulating homeostasis of neurotransmitters, ionostasis, synaptic connectivity, and metabolic support of the central nervous system. Astrocytes are further provisioned with multiple receptors for neurotransmitters and neurohormones, which upon activation trigger intracellular signals mediated by Ca2+, Na+, and cyclic AMP. Calcium signals have distinct organization and underlying mechanisms in different astrocytic compartments thus allowing complex spatiotemporal signaling. Signals mediated by fluctuations in cytosolic Na+ are instrumental for coordination of Na+ dependent astrocytic transporters with tissue state and homeostatic demands. Astroglial ionic excitability may also involve K+, H+, and Cl-. The cyclic AMP signalling system is, in comparison to ions, much slower in targeting astroglial effector mechanisms. This evidence review summarizes the concept of astroglial intracellular excitability.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK,Achucarro Center for Neuroscience, Ikerbasque, 48011 Bilbao, Spain,Address correspondence to A.V. (e-mail: )
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia,Faculty of Biology, Moscow State University, Moscow, Russia,Sechenov First Moscow State Medical University, Moscow, Russia
| | - Robert Zorec
- Celica Biomedical, Ljubljana 1000, Slovenia,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana 1000, Slovenia
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Semyanov A, Henneberger C, Agarwal A. Making sense of astrocytic calcium signals — from acquisition to interpretation. Nat Rev Neurosci 2020; 21:551-564. [DOI: 10.1038/s41583-020-0361-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2020] [Indexed: 12/31/2022]
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