1
|
Thomas CI, Ryan MA, McNabb MC, Kamasawa N, Scholl B. Astrocyte coverage of excitatory synapses correlates to measures of synapse structure and function in ferret primary visual cortex. Glia 2024; 72:1785-1800. [PMID: 38856149 PMCID: PMC11324397 DOI: 10.1002/glia.24582] [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: 12/08/2023] [Revised: 05/25/2024] [Accepted: 06/02/2024] [Indexed: 06/11/2024]
Abstract
Most excitatory synapses in the mammalian brain are contacted or ensheathed by astrocyte processes, forming tripartite synapses. Astrocytes are thought to be critical regulators of the structural and functional dynamics of synapses. While the degree of synaptic coverage by astrocytes is known to vary across brain regions and animal species, the reason for and implications of this variability remains unknown. Further, how astrocyte coverage of synapses relates to in vivo functional properties of individual synapses has not been investigated. Here, we characterized astrocyte coverage of synapses of pyramidal neurons in the ferret visual cortex and, using correlative light and electron microscopy, examined their relationship to synaptic strength and sensory-evoked Ca2+ activity. Nearly, all synapses were contacted by astrocytes, and most were contacted along the axon-spine interface. Structurally, we found that the degree of synaptic astrocyte coverage directly scaled with synapse size and postsynaptic density complexity. Functionally, we found that the amount of astrocyte coverage scaled with how selectively a synapse responds to a particular visual stimulus and, at least for the largest synapses, scaled with the reliability of visual stimuli to evoke postsynaptic Ca2+ events. Our study shows astrocyte coverage is highly correlated with structural metrics of synaptic strength of excitatory synapses in the visual cortex and demonstrates a previously unknown relationship between astrocyte coverage and reliable sensory activation.
Collapse
Affiliation(s)
- Connon I Thomas
- Electron Microscopy Core Facility, Max Planck Florida Institute for Neuroscience, Jupiter, Florida, USA
| | - Melissa A Ryan
- Electron Microscopy Core Facility, Max Planck Florida Institute for Neuroscience, Jupiter, Florida, USA
| | - Micaiah C McNabb
- Electron Microscopy Core Facility, Max Planck Florida Institute for Neuroscience, Jupiter, Florida, USA
| | - Naomi Kamasawa
- Electron Microscopy Core Facility, Max Planck Florida Institute for Neuroscience, Jupiter, Florida, USA
| | - Benjamin Scholl
- Department of Physiology and Biophysics, University of Colorado Denver, Aurora, Colorado, USA
| |
Collapse
|
2
|
Péter M, Héja L. High-Frequency Imaging Reveals Synchronised Delta- and Theta-Band Ca 2+ Oscillations in the Astrocytic Soma In Vivo. Int J Mol Sci 2024; 25:8911. [PMID: 39201597 PMCID: PMC11354863 DOI: 10.3390/ijms25168911] [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: 07/12/2024] [Revised: 08/10/2024] [Accepted: 08/13/2024] [Indexed: 09/02/2024] Open
Abstract
One of the major breakthroughs of neurobiology was the identification of distinct ranges of oscillatory activity in the neuronal network that were found to be responsible for specific biological functions, both physiological and pathological in nature. Astrocytes, physically coupled by gap junctions and possessing the ability to simultaneously modulate the functions of a large number of surrounding synapses, are perfectly positioned to introduce synchronised oscillatory activity into the neural network. However, astrocytic somatic calcium signalling has not been investigated to date in the frequency ranges of common neuronal oscillations, since astrocytes are generally considered to be slow responders in terms of Ca2+ signalling. Using high-frequency two-photon imaging, we reveal fast Ca2+ oscillations in the soma of astrocytes in the delta (0.5-4 Hz) and theta (4-8 Hz) frequency bands in vivo in the rat cortex under ketamine-xylazine anaesthesia, which is known to induce permanent slow-wave sleep. The high-frequency astrocytic Ca2+ signals were not observed under fentanyl anaesthesia, excluding the possibility that the signals were introduced by motion artefacts. We also demonstrate that these fast astrocytic Ca2+ signals, previously considered to be exclusive to neurons, are present in a large number of astrocytes and are phase synchronised at the astrocytic network level. We foresee that the disclosure of these high-frequency astrocytic signals may help with understanding the appearance of synchronised oscillatory signals and may open up new avenues of treatment for neurological conditions characterised by altered neuronal oscillations.
Collapse
Affiliation(s)
- Márton Péter
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117 Budapest, Hungary;
- Hevesy György PhD School of Chemistry, ELTE Eötvös Loránd University, 1117 Budapest, Hungary
| | - László Héja
- Institute of Organic Chemistry, HUN-REN Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117 Budapest, Hungary;
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
Li Y, Li L, Wang Y, Li X, Chen Z. Norepinephrine-Astrocyte Signaling Regulates Cortical State Homeostasis. Neurosci Bull 2024; 40:1021-1024. [PMID: 38739250 PMCID: PMC11250759 DOI: 10.1007/s12264-024-01213-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 02/04/2024] [Indexed: 05/14/2024] Open
Affiliation(s)
- Yulan Li
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Lixuan Li
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Yibei Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Xinyi Li
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China.
| |
Collapse
|
6
|
Sriram S, Carstens K, Dewing W, Fiacco TA. Astrocyte regulation of extracellular space parameters across the sleep-wake cycle. Front Cell Neurosci 2024; 18:1401698. [PMID: 38988660 PMCID: PMC11233815 DOI: 10.3389/fncel.2024.1401698] [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: 03/15/2024] [Accepted: 06/07/2024] [Indexed: 07/12/2024] Open
Abstract
Multiple subfields of neuroscience research are beginning to incorporate astrocytes into current frameworks of understanding overall brain physiology, neuronal circuitry, and disease etiology that underlie sleep and sleep-related disorders. Astrocytes have emerged as a dynamic regulator of neuronal activity through control of extracellular space (ECS) volume and composition, both of which can vary dramatically during different levels of sleep and arousal. Astrocytes are also an attractive target of sleep research due to their prominent role in the glymphatic system, a method by which toxic metabolites generated during wakefulness are cleared away. In this review we assess the literature surrounding glial influences on fluctuations in ECS volume and composition across the sleep-wake cycle. We also examine mechanisms of astrocyte volume regulation in glymphatic solute clearance and their role in sleep and wake states. Overall, findings highlight the importance of astrocytes in sleep and sleep research.
Collapse
Affiliation(s)
- Sandhya Sriram
- Interdepartmental Graduate Program in Neuroscience, University of California, Riverside, Riverside, CA, United States
- Department of Biochemistry and Molecular Biology, University of California, Riverside, Riverside, CA, United States
| | - Kaira Carstens
- Department of Biochemistry and Molecular Biology, University of California, Riverside, Riverside, CA, United States
| | - Wayne Dewing
- Undergraduate Major in Neuroscience, University of California, Riverside, Riverside, CA, United States
| | - Todd A Fiacco
- Interdepartmental Graduate Program in Neuroscience, University of California, Riverside, Riverside, CA, United States
- Department of Biochemistry and Molecular Biology, University of California, Riverside, Riverside, CA, United States
| |
Collapse
|
7
|
Cahill MK, Collard M, Tse V, Reitman ME, Etchenique R, Kirst C, Poskanzer KE. Network-level encoding of local neurotransmitters in cortical astrocytes. Nature 2024; 629:146-153. [PMID: 38632406 PMCID: PMC11062919 DOI: 10.1038/s41586-024-07311-5] [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: 04/03/2023] [Accepted: 03/13/2024] [Indexed: 04/19/2024]
Abstract
Astrocytes, the most abundant non-neuronal cell type in the mammalian brain, are crucial circuit components that respond to and modulate neuronal activity through calcium (Ca2+) signalling1-7. Astrocyte Ca2+ activity is highly heterogeneous and occurs across multiple spatiotemporal scales-from fast, subcellular activity3,4 to slow, synchronized activity across connected astrocyte networks8-10-to influence many processes5,7,11. However, the inputs that drive astrocyte network dynamics remain unclear. Here we used ex vivo and in vivo two-photon astrocyte imaging while mimicking neuronal neurotransmitter inputs at multiple spatiotemporal scales. We find that brief, subcellular inputs of GABA and glutamate lead to widespread, long-lasting astrocyte Ca2+ responses beyond an individual stimulated cell. Further, we find that a key subset of Ca2+ activity-propagative activity-differentiates astrocyte network responses to these two main neurotransmitters, and may influence responses to future inputs. Together, our results demonstrate that local, transient neurotransmitter inputs are encoded by broad cortical astrocyte networks over a minutes-long time course, contributing to accumulating evidence that substantial astrocyte-neuron communication occurs across slow, network-level spatiotemporal scales12-14. These findings will enable future studies to investigate the link between specific astrocyte Ca2+ activity and specific functional outputs, which could build a consistent framework for astrocytic modulation of neuronal activity.
Collapse
Affiliation(s)
- Michelle K Cahill
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
| | - Max Collard
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
| | - Vincent Tse
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, USA
| | - Michael E Reitman
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, USA
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
| | - Roberto Etchenique
- Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CONICET, Buenos Aires, Argentina
| | - Christoph Kirst
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA
- Department of Anatomy, University of California, San Francisco, CA, USA
- Kavli Institute for Fundamental Neuroscience, San Francisco, CA, USA
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Kira E Poskanzer
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA, USA.
- Neuroscience Graduate Program, University of California, San Francisco, CA, USA.
- Kavli Institute for Fundamental Neuroscience, San Francisco, CA, USA.
| |
Collapse
|
8
|
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.
Collapse
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.
| |
Collapse
|
9
|
Gong L, Pasqualetti F, Papouin T, Ching S. Astrocytes as a mechanism for contextually-guided network dynamics and function. PLoS Comput Biol 2024; 20:e1012186. [PMID: 38820533 PMCID: PMC11168681 DOI: 10.1371/journal.pcbi.1012186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 06/12/2024] [Accepted: 05/21/2024] [Indexed: 06/02/2024] Open
Abstract
Astrocytes are a ubiquitous and enigmatic type of non-neuronal cell and are found in the brain of all vertebrates. While traditionally viewed as being supportive of neurons, it is increasingly recognized that astrocytes play a more direct and active role in brain function and neural computation. On account of their sensitivity to a host of physiological covariates and ability to modulate neuronal activity and connectivity on slower time scales, astrocytes may be particularly well poised to modulate the dynamics of neural circuits in functionally salient ways. In the current paper, we seek to capture these features via actionable abstractions within computational models of neuron-astrocyte interaction. Specifically, we engage how nested feedback loops of neuron-astrocyte interaction, acting over separated time-scales, may endow astrocytes with the capability to enable learning in context-dependent settings, where fluctuations in task parameters may occur much more slowly than within-task requirements. We pose a general model of neuron-synapse-astrocyte interaction and use formal analysis to characterize how astrocytic modulation may constitute a form of meta-plasticity, altering the ways in which synapses and neurons adapt as a function of time. We then embed this model in a bandit-based reinforcement learning task environment, and show how the presence of time-scale separated astrocytic modulation enables learning over multiple fluctuating contexts. Indeed, these networks learn far more reliably compared to dynamically homogeneous networks and conventional non-network-based bandit algorithms. Our results fuel the notion that neuron-astrocyte interactions in the brain benefit learning over different time-scales and the conveyance of task-relevant contextual information onto circuit dynamics.
Collapse
Affiliation(s)
- Lulu Gong
- Department of Electrical and Systems Engineering, Washington University, St. Louis, Missouri, United States of America
| | - Fabio Pasqualetti
- Department of Mechanical Engineering, University of California, Riverside, California, United States of America
| | - Thomas Papouin
- Department of Neuroscience, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - ShiNung Ching
- Department of Electrical and Systems Engineering, Washington University, St. Louis, Missouri, United States of America
| |
Collapse
|
10
|
Smyllie NJ, Hastings MH, Patton AP. Neuron-Astrocyte Interactions and Circadian Timekeeping in Mammals. Neuroscientist 2024:10738584241245307. [PMID: 38602223 DOI: 10.1177/10738584241245307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Almost every facet of our behavior and physiology varies predictably over the course of day and night, anticipating and adapting us to their associated opportunities and challenges. These rhythms are driven by endogenous biological clocks that, when deprived of environmental cues, can continue to oscillate within a period of approximately 1 day, hence circa-dian. Normally, retinal signals synchronize them to the cycle of light and darkness, but disruption of circadian organization, a common feature of modern lifestyles, carries considerable costs to health. Circadian timekeeping pivots around a cell-autonomous molecular clock, widely expressed across tissues. These cellular timers are in turn synchronized by the principal circadian clock of the brain: the hypothalamic suprachiasmatic nucleus (SCN). Intercellular signals make the SCN network a very powerful pacemaker. Previously, neurons were considered the sole SCN timekeepers, with glial cells playing supportive roles. New discoveries have revealed, however, that astrocytes are active partners in SCN network timekeeping, with their cell-autonomous clock regulating extracellular glutamate and GABA concentrations to control circadian cycles of SCN neuronal activity. Here, we introduce circadian timekeeping at the cellular and SCN network levels before focusing on the contributions of astrocytes and their mutual interaction with neurons in circadian control in the brain.
Collapse
Affiliation(s)
- Nicola J Smyllie
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | | | - Andrew P Patton
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| |
Collapse
|
11
|
Gau YTA, Hsu ET, Cha RJ, Pak RW, Looger LL, Kang JU, Bergles DE. Multicore fiber optic imaging reveals that astrocyte calcium activity in the mouse cerebral cortex is modulated by internal motivational state. Nat Commun 2024; 15:3039. [PMID: 38589390 PMCID: PMC11002016 DOI: 10.1038/s41467-024-47345-x] [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: 06/11/2023] [Accepted: 03/25/2024] [Indexed: 04/10/2024] Open
Abstract
Astrocytes are a direct target of neuromodulators and can influence neuronal activity on broad spatial and temporal scales in response to a rise in cytosolic calcium. However, our knowledge about how astrocytes are recruited during different animal behaviors remains limited. To measure astrocyte activity calcium in vivo during normative behaviors, we utilize a high-resolution, long working distance multicore fiber optic imaging system that allows visualization of individual astrocyte calcium transients in the cerebral cortex of freely moving mice. We define the spatiotemporal dynamics of astrocyte calcium changes during diverse behaviors, ranging from sleep-wake cycles to the exploration of novel objects, showing that their activity is more variable and less synchronous than apparent in head-immobilized imaging conditions. In accordance with their molecular diversity, individual astrocytes often exhibit distinct thresholds and activity patterns during explorative behaviors, allowing temporal encoding across the astrocyte network. Astrocyte calcium events were induced by noradrenergic and cholinergic systems and modulated by internal state. The distinct activity patterns exhibited by astrocytes provides a means to vary their neuromodulatory influence in different behavioral contexts and internal states.
Collapse
Affiliation(s)
- Yung-Tian A Gau
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA.
| | - Eric T Hsu
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
| | - Richard J Cha
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Rebecca W Pak
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Loren L Looger
- Howard Hughes Medical Institute, Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Jin U Kang
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, USA.
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD, USA.
| | - Dwight E Bergles
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA.
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
12
|
Linne ML. Computational modeling of neuron-glia signaling interactions to unravel cellular and neural circuit functioning. Curr Opin Neurobiol 2024; 85:102838. [PMID: 38310660 DOI: 10.1016/j.conb.2023.102838] [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: 03/10/2023] [Revised: 12/22/2023] [Accepted: 12/29/2023] [Indexed: 02/06/2024]
Abstract
Glial cells have been shown to be vital for various brain functions, including homeostasis, information processing, and cognition. Over the past 30 years, various signaling interactions between neuronal and glial cells have been shown to underlie these functions. This review summarizes the interactions, particularly between neurons and astrocytes, which are types of glial cells. Some of the interactions remain controversial in part due to the nature of experimental methods and preparations used. Based on the accumulated data, computational models of the neuron-astrocyte interactions have been developed to explain the complex functions of astrocytes in neural circuits and to test conflicting hypotheses. This review presents the most significant recent models, modeling methods and simulation tools for neuron-astrocyte interactions. In the future, we will especially need more experimental research on awake animals in vivo and new computational models of neuron-glia interactions to advance our understanding of cellular dynamics and the functioning of neural circuits in different brain regions.
Collapse
Affiliation(s)
- Marja-Leena Linne
- Tampere University, Faculty of Medicine and Health Technology, Tampere, Finland.
| |
Collapse
|
13
|
Almeida VN. Somatostatin and the pathophysiology of Alzheimer's disease. Ageing Res Rev 2024; 96:102270. [PMID: 38484981 DOI: 10.1016/j.arr.2024.102270] [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: 07/18/2023] [Revised: 03/09/2024] [Accepted: 03/09/2024] [Indexed: 03/28/2024]
Abstract
Among the central features of Alzheimer's disease (AD) progression are altered levels of the neuropeptide somatostatin (SST), and the colocalisation of SST-positive interneurons (SST-INs) with amyloid-β plaques, leading to cell death. In this theoretical review, I propose a molecular model for the pathogenesis of AD based on SST-IN hypofunction and hyperactivity. Namely, hypofunctional and hyperactive SST-INs struggle to control hyperactivity in medial regions in early stages, leading to axonal Aβ production through excessive presynaptic GABAB inhibition, GABAB1a/APP complex downregulation and internalisation. Concomitantly, excessive SST-14 release accumulates near SST-INs in the form of amyloids, which bind to Aβ to form toxic mixed oligomers. This leads to differential SST-IN death through excitotoxicity, further disinhibition, SST deficits, and increased Aβ release, fibrillation and plaque formation. Aβ plaques, hyperactive networks and SST-IN distributions thereby tightly overlap in the brain. Conversely, chronic stimulation of postsynaptic SST2/4 on gulutamatergic neurons by hyperactive SST-INs promotes intense Mitogen-Activated Protein Kinase (MAPK) p38 activity, leading to somatodendritic p-tau staining and apoptosis/neurodegeneration - in agreement with a near complete overlap between p38 and neurofibrillary tangles. This model is suitable to explain some of the principal risk factors and markers of AD progression, including mitochondrial dysfunction, APOE4 genotype, sex-dependent vulnerability, overactive glial cells, dystrophic neurites, synaptic/spine losses, inter alia. Finally, the model can also shed light on qualitative aspects of AD neuropsychology, especially within the domains of spatial and declarative (episodic, semantic) memory, under an overlying pattern of contextual indiscrimination, ensemble instability, interference and generalisation.
Collapse
Affiliation(s)
- Victor N Almeida
- Institute of Psychiatry, Faculty of Medicine, University of São Paulo (USP), Brazil; Faculty of Languages, Federal University of Minas Gerais (UFMG), Brazil.
| |
Collapse
|
14
|
Abstract
The brain is a complex organ, fundamentally changing across the day to perform basic functions like sleep, thought, and regulating whole-body physiology. This requires a complex symphony of nutrients, hormones, ions, neurotransmitters and more to be properly distributed across the brain to maintain homeostasis throughout 24 hours. These solutes are distributed both by the blood and by cerebrospinal fluid. Cerebrospinal fluid contents are distinct from the general circulation because of regulation at brain barriers including the choroid plexus, glymphatic system, and blood-brain barrier. In this review, we discuss the overlapping circadian (≈24-hour) rhythms in brain fluid biology and at the brain barriers. Our goal is for the reader to gain both a fundamental understanding of brain barriers alongside an understanding of the interactions between these fluids and the circadian timing system. Ultimately, this review will provide new insight into how alterations in these finely tuned clocks may lead to pathology.
Collapse
Affiliation(s)
- Velia S Vizcarra
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Ryann M Fame
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Lauren M Hablitz
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| |
Collapse
|
15
|
Wang J, Cheng P, Qu Y, Zhu G. Astrocytes and Memory: Implications for the Treatment of Memory-related Disorders. Curr Neuropharmacol 2024; 22:2217-2239. [PMID: 38288836 PMCID: PMC11337689 DOI: 10.2174/1570159x22666240128102039] [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: 09/06/2023] [Accepted: 10/29/2023] [Indexed: 08/23/2024] Open
Abstract
Memory refers to the imprint accumulated in the brain by life experiences and represents the basis for humans to engage in advanced psychological activities such as thinking and imagination. Previously, research activities focused on memory have always targeted neurons. However, in addition to neurons, astrocytes are also involved in the encoding, consolidation, and extinction of memory. In particular, astrocytes are known to affect the recruitment and function of neurons at the level of local synapses and brain networks. Moreover, the involvement of astrocytes in memory and memory-related disorders, especially in Alzheimer's disease (AD) and post-traumatic stress disorder (PTSD), has been investigated extensively. In this review, we describe the unique contributions of astrocytes to synaptic plasticity and neuronal networks and discuss the role of astrocytes in different types of memory processing. In addition, we also explore the roles of astrocytes in the pathogenesis of memory-related disorders, such as AD, brain aging, PTSD and addiction, thus suggesting that targeting astrocytes may represent a potential strategy to treat memory-related neurological diseases. In conclusion, this review emphasizes that thinking from the perspective of astrocytes will provide new ideas for the diagnosis and therapy of memory-related neurological disorders.
Collapse
Affiliation(s)
- Juan Wang
- Key Laboratory of Xin’an Medicine, The Ministry of Education and Key Laboratory of Molecular Biology (Brain Diseases), Anhui University of Chinese Medicine, Hefei 230012, China
| | - Ping Cheng
- Key Laboratory of Xin’an Medicine, The Ministry of Education and Key Laboratory of Molecular Biology (Brain Diseases), Anhui University of Chinese Medicine, Hefei 230012, China
| | - Yan Qu
- Key Laboratory of Xin’an Medicine, The Ministry of Education and Key Laboratory of Molecular Biology (Brain Diseases), Anhui University of Chinese Medicine, Hefei 230012, China
| | - Guoqi Zhu
- Key Laboratory of Xin’an Medicine, The Ministry of Education and Key Laboratory of Molecular Biology (Brain Diseases), Anhui University of Chinese Medicine, Hefei 230012, China
| |
Collapse
|
16
|
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.
Collapse
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.
| |
Collapse
|
17
|
Le L, Miyanishi K, Tanaka J, Majewska AK. Microglial Regulation of Sleep and Wakefulness. ADVANCES IN NEUROBIOLOGY 2024; 37:243-260. [PMID: 39207696 DOI: 10.1007/978-3-031-55529-9_14] [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: 09/04/2024]
Abstract
Sleep serves a multitude of roles in brain maturation and function. Although the neural networks involved in sleep regulation have been extensively characterized, it is increasingly recognized that neurons are not the sole conductor orchestrating the rhythmic cycle of sleep and wakefulness. In the central nervous system, microglia have emerged as an important player in sleep regulation. Within the last two decades, microglia have gained substantial attention for carrying out numerous nonimmune tasks that are crucial for brain development and function by co-opting similar mechanisms used in their conventional immune functions. Here, we highlight the importance of microglia in sleep regulation with recent findings reporting an arrhythmic sleep/wake cycle in the absence of microglia. Although the underlying mechanisms for such regulation are still being uncovered, it is likely that microglial contributions to the rhythmic control of the sleep/wake cycle come from their influence on synaptic strength and neuronal activity. We review the current literature to provide speculative signaling pathways and suggest key questions for future research. Advancing our knowledge of the mechanistic contribution of microglia to sleep regulation will not only further our insight into this critical biological process but also be instrumental in providing novel therapeutic strategies for sleep disorders.
Collapse
Affiliation(s)
- Linh Le
- Department of Neuroscience, Del Monte Institute of Neuroscience, Center for Visual Science, Neuroscience Graduate Program, University of Rochester, Rochester, NY, USA
| | - Kazuya Miyanishi
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Junya Tanaka
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Ehime University, Toon, Japan.
| | - Ania K Majewska
- Department of Neuroscience, Del Monte Institute of Neuroscience, Center for Visual Science, Neuroscience Graduate Program, University of Rochester, Rochester, NY, USA.
| |
Collapse
|
18
|
Cahill MK, Collard M, Tse V, Reitman ME, Etchenique R, Kirst C, Poskanzer KE. Network-level encoding of local neurotransmitters in cortical astrocytes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.01.568932. [PMID: 38106119 PMCID: PMC10723263 DOI: 10.1101/2023.12.01.568932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Astrocytes-the most abundant non-neuronal cell type in the mammalian brain-are crucial circuit components that respond to and modulate neuronal activity via calcium (Ca 2+ ) signaling 1-8 . Astrocyte Ca 2+ activity is highly heterogeneous and occurs across multiple spatiotemporal scales: from fast, subcellular activity 3,4 to slow, synchronized activity that travels across connected astrocyte networks 9-11 . Furthermore, astrocyte network activity has been shown to influence a wide range of processes 5,8,12 . While astrocyte network activity has important implications for neuronal circuit function, the inputs that drive astrocyte network dynamics remain unclear. Here we used ex vivo and in vivo two-photon Ca 2+ imaging of astrocytes while mimicking neuronal neurotransmitter inputs at multiple spatiotemporal scales. We find that brief, subcellular inputs of GABA and glutamate lead to widespread, long-lasting astrocyte Ca 2+ responses beyond an individual stimulated cell. Further, we find that a key subset of Ca 2+ activity-propagative events-differentiates astrocyte network responses to these two major neurotransmitters, and gates responses to future inputs. Together, our results demonstrate that local, transient neurotransmitter inputs are encoded by broad cortical astrocyte networks over the course of minutes, contributing to accumulating evidence across multiple model organisms that significant astrocyte-neuron communication occurs across slow, network-level spatiotemporal scales 13-15 . We anticipate that this study will be a starting point for future studies investigating the link between specific astrocyte Ca 2+ activity and specific astrocyte functional outputs, which could build a consistent framework for astrocytic modulation of neuronal activity.
Collapse
|
19
|
Wang Y, Wang L, Fan H, Ma J, Cao H, Wang X. Breathing cluster in complex neuron-astrocyte networks. CHAOS (WOODBURY, N.Y.) 2023; 33:113118. [PMID: 37967261 DOI: 10.1063/5.0146906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 10/20/2023] [Indexed: 11/17/2023]
Abstract
Brain activities are featured by spatially distributed neural clusters of coherent firings and a spontaneous slow switching of the clusters between the coherent and incoherent states. Evidences from recent in vivo experiments suggest that astrocytes, a type of glial cell regarded previously as providing only structural and metabolic supports to neurons, participate actively in brain functions by regulating the neural firing activities, yet the underlying mechanism remains unknown. Here, introducing astrocyte as a reservoir of the glutamate released from the neuron synapses, we propose the model of the complex neuron-astrocyte network, and investigate the roles of astrocytes in regulating the cluster synchronization behaviors of networked chaotic neurons. It is found that a specific set of neurons on the network are synchronized and form a cluster, while the remaining neurons are kept as desynchronized. Moreover, during the course of network evolution, the cluster is switching between the synchrony and asynchrony states in an intermittent fashion, henceforth the phenomenon of "breathing cluster." By the method of symmetry-based analysis, we conduct a theoretical investigation on the synchronizability of the cluster. It is revealed that the contents of the cluster are determined by the network symmetry, while the breathing of the cluster is attributed to the interplay between the neural network and the astrocyte. The phenomenon of breathing cluster is demonstrated in different network models, including networks with different sizes, nodal dynamics, and coupling functions. The findings shed light on the cellular mechanism of astrocytes in regulating neural activities and give insights into the state-switching of the neocortex.
Collapse
Affiliation(s)
- Ya Wang
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
| | - Liang Wang
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
| | - Huawei Fan
- School of Science, Xi'an University of Posts and Telecommunications, Xi'an 710121, China
| | - Jun Ma
- Department of Physics, Lanzhou University of Technology, Lanzhou 730050, China
| | - Hui Cao
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
| | - Xingang Wang
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China
| |
Collapse
|
20
|
Jorstad NL, Song JH, Exposito-Alonso D, Suresh H, Castro-Pacheco N, Krienen FM, Yanny AM, Close J, Gelfand E, Long B, Seeman SC, Travaglini KJ, Basu S, Beaudin M, Bertagnolli D, Crow M, Ding SL, Eggermont J, Glandon A, Goldy J, Kiick K, Kroes T, McMillen D, Pham T, Rimorin C, Siletti K, Somasundaram S, Tieu M, Torkelson A, Feng G, Hopkins WD, Höllt T, Keene CD, Linnarsson S, McCarroll SA, Lelieveldt BP, Sherwood CC, Smith K, Walsh CA, Dobin A, Gillis J, Lein ES, Hodge RD, Bakken TE. Comparative transcriptomics reveals human-specific cortical features. Science 2023; 382:eade9516. [PMID: 37824638 PMCID: PMC10659116 DOI: 10.1126/science.ade9516] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 09/13/2023] [Indexed: 10/14/2023]
Abstract
The cognitive abilities of humans are distinctive among primates, but their molecular and cellular substrates are poorly understood. We used comparative single-nucleus transcriptomics to analyze samples of the middle temporal gyrus (MTG) from adult humans, chimpanzees, gorillas, rhesus macaques, and common marmosets to understand human-specific features of the neocortex. Human, chimpanzee, and gorilla MTG showed highly similar cell-type composition and laminar organization as well as a large shift in proportions of deep-layer intratelencephalic-projecting neurons compared with macaque and marmoset MTG. Microglia, astrocytes, and oligodendrocytes had more-divergent expression across species compared with neurons or oligodendrocyte precursor cells, and neuronal expression diverged more rapidly on the human lineage. Only a few hundred genes showed human-specific patterning, suggesting that relatively few cellular and molecular changes distinctively define adult human cortical structure.
Collapse
Affiliation(s)
| | - Janet H.T. Song
- Allen Discovery Center for Human Brain Evolution, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Pediatrics and Neurology, Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, MA 02115, USA
| | - David Exposito-Alonso
- Allen Discovery Center for Human Brain Evolution, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Pediatrics and Neurology, Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Hamsini Suresh
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | | | - Fenna M. Krienen
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | | | - Jennie Close
- Allen Institute for Brain Science; Seattle, WA, 98109, USA
| | - Emily Gelfand
- Allen Institute for Brain Science; Seattle, WA, 98109, USA
| | - Brian Long
- Allen Institute for Brain Science; Seattle, WA, 98109, USA
| | | | | | - Soumyadeep Basu
- LKEB, Dept of Radiology, Leiden University Medical Center; Leiden, The Netherlands
- Computer Graphics and Visualization Group, Delft University of Technology, Delft, Netherlands
| | - Marc Beaudin
- Allen Discovery Center for Human Brain Evolution, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Pediatrics and Neurology, Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, MA 02115, USA
| | | | - Megan Crow
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
- Stanley Institute for Cognitive Genomics, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Song-Lin Ding
- Allen Institute for Brain Science; Seattle, WA, 98109, USA
| | - Jeroen Eggermont
- LKEB, Dept of Radiology, Leiden University Medical Center; Leiden, The Netherlands
| | | | - Jeff Goldy
- Allen Institute for Brain Science; Seattle, WA, 98109, USA
| | - Katelyn Kiick
- Allen Institute for Brain Science; Seattle, WA, 98109, USA
| | - Thomas Kroes
- LKEB, Dept of Radiology, Leiden University Medical Center; Leiden, The Netherlands
| | | | | | | | - Kimberly Siletti
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | | | - Michael Tieu
- Allen Institute for Brain Science; Seattle, WA, 98109, USA
| | - Amy Torkelson
- Allen Institute for Brain Science; Seattle, WA, 98109, USA
| | - Guoping Feng
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - William D. Hopkins
- Keeling Center for Comparative Medicine and Research, University of Texas, MD Anderson Cancer Center, Houston, TX 78602, USA
| | - Thomas Höllt
- Computer Graphics and Visualization Group, Delft University of Technology, Delft, Netherlands
| | - C. Dirk Keene
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 981915, USA
| | - Sten Linnarsson
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Steven A. McCarroll
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Boudewijn P. Lelieveldt
- LKEB, Dept of Radiology, Leiden University Medical Center; Leiden, The Netherlands
- Pattern Recognition and Bioinformatics group, Delft University of Technology, Delft, Netherlands
| | - Chet C. Sherwood
- Department of Anthropology, The George Washington University, Washington, DC 20037, USA
| | - Kimberly Smith
- Allen Institute for Brain Science; Seattle, WA, 98109, USA
| | - Christopher A. Walsh
- Allen Discovery Center for Human Brain Evolution, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Pediatrics and Neurology, Harvard Medical School, Boston, MA 02115, USA
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Alexander Dobin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Jesse Gillis
- Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Ed S. Lein
- Allen Institute for Brain Science; Seattle, WA, 98109, USA
| | | | | |
Collapse
|
21
|
Hyung S, Park JH, Jung K. Application of optogenetic glial cells to neuron-glial communication. Front Cell Neurosci 2023; 17:1249043. [PMID: 37868193 PMCID: PMC10585272 DOI: 10.3389/fncel.2023.1249043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 09/15/2023] [Indexed: 10/24/2023] Open
Abstract
Optogenetic techniques combine optics and genetics to enable cell-specific targeting and precise spatiotemporal control of excitable cells, and they are increasingly being employed. One of the most significant advantages of the optogenetic approach is that it allows for the modulation of nearby cells or circuits with millisecond precision, enabling researchers to gain a better understanding of the complex nervous system. Furthermore, optogenetic neuron activation permits the regulation of information processing in the brain, including synaptic activity and transmission, and also promotes nerve structure development. However, the optimal conditions remain unclear, and further research is required to identify the types of cells that can most effectively and precisely control nerve function. Recent studies have described optogenetic glial manipulation for coordinating the reciprocal communication between neurons and glia. Optogenetically stimulated glial cells can modulate information processing in the central nervous system and provide structural support for nerve fibers in the peripheral nervous system. These advances promote the effective use of optogenetics, although further experiments are needed. This review describes the critical role of glial cells in the nervous system and reviews the optogenetic applications of several types of glial cells, as well as their significance in neuron-glia interactions. Together, it briefly discusses the therapeutic potential and feasibility of optogenetics.
Collapse
Affiliation(s)
- Sujin Hyung
- Precision Medicine Research Institute, Samsung Medical Center, Seoul, Republic of Korea
- Division of Hematology-Oncology, Department of Medicine, Sungkyunkwan University, Samsung Medical Center, Seoul, Republic of Korea
| | - Ji-Hye Park
- Graduate School of Cancer Science and Policy, Cancer Biomedical Science, National Cancer Center, Goyang-si, Gyeonggi-do, Republic of Korea
| | - Kyuhwan Jung
- DAWINBIO Inc., Hanam-si, Gyeonggi-do, Republic of Korea
| |
Collapse
|
22
|
de Ceglia R, Ledonne A, Litvin DG, Lind BL, Carriero G, Latagliata EC, Bindocci E, Di Castro MA, Savtchouk I, Vitali I, Ranjak A, Congiu M, Canonica T, Wisden W, Harris K, Mameli M, Mercuri N, Telley L, Volterra A. Specialized astrocytes mediate glutamatergic gliotransmission in the CNS. Nature 2023; 622:120-129. [PMID: 37674083 PMCID: PMC10550825 DOI: 10.1038/s41586-023-06502-w] [Citation(s) in RCA: 50] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/31/2023] [Indexed: 09/08/2023]
Abstract
Multimodal astrocyte-neuron communications govern brain circuitry assembly and function1. For example, through rapid glutamate release, astrocytes can control excitability, plasticity and synchronous activity2,3 of synaptic networks, while also contributing to their dysregulation in neuropsychiatric conditions4-7. For astrocytes to communicate through fast focal glutamate release, they should possess an apparatus for Ca2+-dependent exocytosis similar to neurons8-10. However, the existence of this mechanism has been questioned11-13 owing to inconsistent data14-17 and a lack of direct supporting evidence. Here we revisited the astrocyte glutamate exocytosis hypothesis by considering the emerging molecular heterogeneity of astrocytes18-21 and using molecular, bioinformatic and imaging approaches, together with cell-specific genetic tools that interfere with glutamate exocytosis in vivo. By analysing existing single-cell RNA-sequencing databases and our patch-seq data, we identified nine molecularly distinct clusters of hippocampal astrocytes, among which we found a notable subpopulation that selectively expressed synaptic-like glutamate-release machinery and localized to discrete hippocampal sites. Using GluSnFR-based glutamate imaging22 in situ and in vivo, we identified a corresponding astrocyte subgroup that responds reliably to astrocyte-selective stimulations with subsecond glutamate release events at spatially precise hotspots, which were suppressed by astrocyte-targeted deletion of vesicular glutamate transporter 1 (VGLUT1). Furthermore, deletion of this transporter or its isoform VGLUT2 revealed specific contributions of glutamatergic astrocytes in cortico-hippocampal and nigrostriatal circuits during normal behaviour and pathological processes. By uncovering this atypical subpopulation of specialized astrocytes in the adult brain, we provide insights into the complex roles of astrocytes in central nervous system (CNS) physiology and diseases, and identify a potential therapeutic target.
Collapse
Affiliation(s)
- Roberta de Ceglia
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
| | - Ada Ledonne
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
- Department of Experimental Neuroscience, IRCCS Santa Lucia Foundation, Rome, Italy
| | - David Gregory Litvin
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
- Wyss Center for Bio and Neuro Engineering, Campus Biotech, Geneva, Switzerland
| | - Barbara Lykke Lind
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Giovanni Carriero
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
| | | | - Erika Bindocci
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
| | | | - Iaroslav Savtchouk
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
- Department of Biomedical Sciences, Marquette University, Milwaukee, WI, USA
| | - Ilaria Vitali
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
| | - Anurag Ranjak
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
| | - Mauro Congiu
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
| | - Tara Canonica
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
| | - William Wisden
- Department of Life Sciences and UK Dementia Research Institute, Imperial College London, London, UK
| | - Kenneth Harris
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Manuel Mameli
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland
| | - Nicola Mercuri
- Department of Experimental Neuroscience, IRCCS Santa Lucia Foundation, Rome, Italy
- Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy
| | - Ludovic Telley
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland.
| | - Andrea Volterra
- Department of Fundamental Neuroscience, University of Lausanne, Lausanne, Switzerland.
- Wyss Center for Bio and Neuro Engineering, Campus Biotech, Geneva, Switzerland.
| |
Collapse
|
23
|
Brazhe A, Verisokin A, Verveyko D, Postnov D. Astrocytes: new evidence, new models, new roles. Biophys Rev 2023; 15:1303-1333. [PMID: 37975000 PMCID: PMC10643736 DOI: 10.1007/s12551-023-01145-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 09/08/2023] [Indexed: 11/19/2023] Open
Abstract
Astrocytes have been in the limelight of active research for about 3 decades now. Over this period, ideas about their function and role in the nervous system have evolved from simple assistance in energy supply and homeostasis maintenance to a complex informational and metabolic hub that integrates data on local neuronal activity, sensory and arousal context, and orchestrates many crucial processes in the brain. Rapid progress in experimental techniques and data analysis produces a growing body of data, which can be used as a foundation for formulation of new hypotheses, building new refined mathematical models, and ultimately should lead to a new level of understanding of the contribution of astrocytes to the cognitive tasks performed by the brain. Here, we highlight recent progress in astrocyte research, which we believe expands our understanding of how low-level signaling at a cellular level builds up to processes at the level of the whole brain and animal behavior. We start our review with revisiting data on the role of noradrenaline-mediated astrocytic signaling in locomotion, arousal, sensory integration, memory, and sleep. We then briefly review astrocyte contribution to the regulation of cerebral blood flow regulation, which is followed by a discussion of biophysical mechanisms underlying astrocyte effects on different brain processes. The experimental section is closed by an overview of recent experimental techniques available for modulation and visualization of astrocyte dynamics. We then evaluate how the new data can be potentially incorporated into the new mathematical models or where and how it already has been done. Finally, we discuss an interesting prospect that astrocytes may be key players in important processes such as the switching between sleep and wakefulness and the removal of toxic metabolites from the brain milieu.
Collapse
Affiliation(s)
- Alexey Brazhe
- Department of Biophysics, Biological Faculty, Lomonosov Moscow State University, Leninskie Gory, 1/24, Moscow, 119234 Russia
- Department of Molecular Neurobiology, Institute of Bioorganic Chemistry RAS, GSP-7, Miklukho-Maklay Str., 16/10, Moscow, 117997 Russia
| | - Andrey Verisokin
- Department of Theoretical Physics, Kursk State University, Radishcheva st., 33, Kursk, 305000 Russia
| | - Darya Verveyko
- Department of Theoretical Physics, Kursk State University, Radishcheva st., 33, Kursk, 305000 Russia
| | - Dmitry Postnov
- Department of Optics and Biophotonics, Saratov State University, Astrakhanskaya st., 83, Saratov, 410012 Russia
| |
Collapse
|
24
|
Hastings N, Yu Y, Huang B, Middya S, Inaoka M, Erkamp NA, Mason RJ, Carnicer‐Lombarte A, Rahman S, Knowles TPJ, Bance M, Malliaras GG, Kotter MRN. Electrophysiological In Vitro Study of Long-Range Signal Transmission by Astrocytic Networks. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2301756. [PMID: 37485646 PMCID: PMC10582426 DOI: 10.1002/advs.202301756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/09/2023] [Indexed: 07/25/2023]
Abstract
Astrocytes are diverse brain cells that form large networks communicating via gap junctions and chemical transmitters. Despite recent advances, the functions of astrocytic networks in information processing in the brain are not fully understood. In culture, brain slices, and in vivo, astrocytes, and neurons grow in tight association, making it challenging to establish whether signals that spread within astrocytic networks communicate with neuronal groups at distant sites, or whether astrocytes solely respond to their local environments. A multi-electrode array (MEA)-based device called AstroMEA is designed to separate neuronal and astrocytic networks, thus allowing to study the transfer of chemical and/or electrical signals transmitted via astrocytic networks capable of changing neuronal electrical behavior. AstroMEA demonstrates that cortical astrocytic networks can induce a significant upregulation in the firing frequency of neurons in response to a theta-burst charge-balanced biphasic current stimulation (5 pulses of 100 Hz × 10 with 200 ms intervals, 2 s total duration) of a separate neuronal-astrocytic group in the absence of direct neuronal contact. This result corroborates the view of astrocytic networks as a parallel mechanism of signal transmission in the brain that is separate from the neuronal connectome. Translationally, it highlights the importance of astrocytic network protection as a treatment target.
Collapse
Affiliation(s)
- Nataly Hastings
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Yi‐Lin Yu
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Department of Neurological SurgeryTri‐Service General HospitalNational Defence Medical CentreTaipei, Neihu District11490Taiwan
| | - Botian Huang
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | - Sagnik Middya
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Misaki Inaoka
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Nadia A. Erkamp
- Yusuf Hamied Department of ChemistryCentre for Misfolding DiseasesUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
| | - Roger J. Mason
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | | | - Saifur Rahman
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
| | - Tuomas P. J. Knowles
- Yusuf Hamied Department of ChemistryCentre for Misfolding DiseasesUniversity of CambridgeLensfield RoadCambridgeCB2 1EWUK
- Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeJ J Thomson AveCambridgeCB3 0HEUK
| | - Manohar Bance
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
| | - George G. Malliaras
- Electrical Engineering DivisionDepartment of EngineeringUniversity of CambridgeCambridgeCB3 0FAUK
| | - Mark R. N. Kotter
- Department of Clinical NeurosciencesUniversity of CambridgeCambridgeCB2 0QQUK
- Wellcome‐MRC Cambridge Stem Cell InstituteUniversity of CambridgeCambridgeCB2 0AWUK
| |
Collapse
|
25
|
Suo Q, Deng L, Chen T, Wu S, Qi L, Liu Z, He T, Tian HL, Li W, Tang Y, Yang GY, Zhang Z. Optogenetic Activation of Astrocytes Reduces Blood-Brain Barrier Disruption via IL-10 In Stroke. Aging Dis 2023; 14:1870-1886. [PMID: 37196130 PMCID: PMC10529757 DOI: 10.14336/ad.2023.0226] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 02/26/2023] [Indexed: 05/19/2023] Open
Abstract
Optogenetics has been used to regulate astrocyte activity and modulate neuronal function after brain injury. Activated astrocytes regulate blood-brain barrier functions and are thereby involved in brain repair. However, the effect and molecular mechanism of optogenetic-activated astrocytes on the change in barrier function in ischemic stroke remain obscure. In this study, adult male GFAP-ChR2-EYFP transgenic Sprague-Dawley rats were stimulated by optogenetics at 24, 36, 48, and 60 h after photothrombotic stroke to activate ipsilateral cortical astrocytes. The effects of activated astrocytes on barrier integrity and the underlying mechanisms were explored using immunostaining, western blotting, RT-qPCR, and shRNA interference. Neurobehavioral tests were performed to evaluate therapeutic efficacy. The results demonstrated that IgG leakage, gap formation of tight junction proteins, and matrix metallopeptidase 2 expression were reduced after optogenetic activation of astrocytes (p<0.05). Moreover, photo-stimulation of astrocytes protected neurons against apoptosis and improved neurobehavioral outcomes in stroke rats compared to controls (p<0.05). Notably, interleukin-10 expression in optogenetic-activated astrocytes significantly increased after ischemic stroke in rats. Inhibition of interleukin-10 in astrocytes compromised the protective effects of optogenetic-activated astrocytes (p<0.05). We found for the first time that interleukin-10 derived from optogenetic-activated astrocytes protected blood-brain barrier integrity by decreasing the activity of matrix metallopeptidase 2 and attenuated neuronal apoptosis, which provided a novel therapeutic approach and target in the acute stage of ischemic stroke.
Collapse
Affiliation(s)
- Qian Suo
- Shanghai Jiao Tong Affiliated Sixth People’s Hospital, and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| | - Lidong Deng
- Shanghai Jiao Tong Affiliated Sixth People’s Hospital, and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| | - Tingting Chen
- Shanghai Jiao Tong Affiliated Sixth People’s Hospital, and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| | - Shengju Wu
- Shanghai Jiao Tong Affiliated Sixth People’s Hospital, and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| | - Lin Qi
- Shanghai Jiao Tong Affiliated Sixth People’s Hospital, and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| | - Ze Liu
- Shanghai Jiao Tong Affiliated Sixth People’s Hospital, and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| | - Tingting He
- Department of Neurology, Shanghai Tenth People's Hospital, Tongji University, Shanghai, China
| | - Heng-Li Tian
- Department of Neurosurgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
| | - Wanlu Li
- Shanghai Jiao Tong Affiliated Sixth People’s Hospital, and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| | - Yaohui Tang
- Shanghai Jiao Tong Affiliated Sixth People’s Hospital, and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| | - Guo-Yuan Yang
- Shanghai Jiao Tong Affiliated Sixth People’s Hospital, and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| | - Zhijun Zhang
- Shanghai Jiao Tong Affiliated Sixth People’s Hospital, and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
| |
Collapse
|
26
|
Lee YF, Russ AN, Zhao Q, Perle SJ, Maci M, Miller MR, Hou SS, Algamal M, Zhao Z, Li H, Gelwan N, Liu Z, Gomperts SN, Araque A, Galea E, Bacskai BJ, Kastanenka KV. Optogenetic targeting of astrocytes restores slow brain rhythm function and slows Alzheimer's disease pathology. Sci Rep 2023; 13:13075. [PMID: 37567942 PMCID: PMC10421876 DOI: 10.1038/s41598-023-40402-3] [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: 04/13/2023] [Accepted: 08/09/2023] [Indexed: 08/13/2023] Open
Abstract
Patients with Alzheimer's disease (AD) exhibit non-rapid eye movement (NREM) sleep disturbances in addition to memory deficits. Disruption of NREM slow waves occurs early in the disease progression and is recapitulated in transgenic mouse models of beta-amyloidosis. However, the mechanisms underlying slow-wave disruptions remain unknown. Because astrocytes contribute to slow-wave activity, we used multiphoton microscopy and optogenetics to investigate whether they contribute to slow-wave disruptions in APP/PS1 mice. The power but not the frequency of astrocytic calcium transients was reduced in APP/PS1 mice compared to nontransgenic controls. Optogenetic activation of astrocytes at the endogenous frequency of slow waves restored slow-wave power, reduced amyloid deposition, prevented neuronal calcium elevations, and improved memory performance. Our findings revealed malfunction of the astrocytic network driving slow-wave disruptions. Thus, targeting astrocytes to restore circuit activity underlying sleep and memory disruptions in AD could ameliorate disease progression.
Collapse
Affiliation(s)
- Yee Fun Lee
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, 02118, USA
| | - Alyssa N Russ
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Qiuchen Zhao
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Stephen J Perle
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Megi Maci
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Morgan R Miller
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Steven S Hou
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Moustafa Algamal
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Zhuoyang Zhao
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Hanyan Li
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Noah Gelwan
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Zhe Liu
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Stephen N Gomperts
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Elena Galea
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Brian J Bacskai
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA.
| | - Ksenia V Kastanenka
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA.
| |
Collapse
|
27
|
Gebicke-Haerter PJ. The computational power of the human brain. Front Cell Neurosci 2023; 17:1220030. [PMID: 37608987 PMCID: PMC10441807 DOI: 10.3389/fncel.2023.1220030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 07/05/2023] [Indexed: 08/24/2023] Open
Abstract
At the end of the 20th century, analog systems in computer science have been widely replaced by digital systems due to their higher computing power. Nevertheless, the question keeps being intriguing until now: is the brain analog or digital? Initially, the latter has been favored, considering it as a Turing machine that works like a digital computer. However, more recently, digital and analog processes have been combined to implant human behavior in robots, endowing them with artificial intelligence (AI). Therefore, we think it is timely to compare mathematical models with the biology of computation in the brain. To this end, digital and analog processes clearly identified in cellular and molecular interactions in the Central Nervous System are highlighted. But above that, we try to pinpoint reasons distinguishing in silico computation from salient features of biological computation. First, genuinely analog information processing has been observed in electrical synapses and through gap junctions, the latter both in neurons and astrocytes. Apparently opposed to that, neuronal action potentials (APs) or spikes represent clearly digital events, like the yes/no or 1/0 of a Turing machine. However, spikes are rarely uniform, but can vary in amplitude and widths, which has significant, differential effects on transmitter release at the presynaptic terminal, where notwithstanding the quantal (vesicular) release itself is digital. Conversely, at the dendritic site of the postsynaptic neuron, there are numerous analog events of computation. Moreover, synaptic transmission of information is not only neuronal, but heavily influenced by astrocytes tightly ensheathing the majority of synapses in brain (tripartite synapse). At least at this point, LTP and LTD modifying synaptic plasticity and believed to induce short and long-term memory processes including consolidation (equivalent to RAM and ROM in electronic devices) have to be discussed. The present knowledge of how the brain stores and retrieves memories includes a variety of options (e.g., neuronal network oscillations, engram cells, astrocytic syncytium). Also epigenetic features play crucial roles in memory formation and its consolidation, which necessarily guides to molecular events like gene transcription and translation. In conclusion, brain computation is not only digital or analog, or a combination of both, but encompasses features in parallel, and of higher orders of complexity.
Collapse
Affiliation(s)
- Peter J. Gebicke-Haerter
- Institute of Psychopharmacology, Central Institute of Mental Health, Faculty of Medicine, University of Heidelberg, Mannheim, Germany
| |
Collapse
|
28
|
Lines J, Baraibar AM, Nanclares C, Martin E, Aguilar JDLR, Kofuji P, Navarrete M, Araque A. A spatial threshold for astrocyte calcium surge. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.18.549563. [PMID: 37503130 PMCID: PMC10370153 DOI: 10.1101/2023.07.18.549563] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Astrocytes are active cells involved in brain function through the bidirectional communication with neurons, in which the astrocyte calcium signal plays a crucial role. Synaptically-evoked calcium increases can be localized to independent subcellular domains or expand to the entire cell, i.e., calcium surge. In turn, astrocytes may regulate individual synapses by calcium-dependent release of gliotransmitters. Because a single astrocyte may contact ~100,000 synapses, the control of the intracellular calcium signal propagation may have relevant consequences on brain function by regulating the spatial range of astrocyte neuromodulation of synapses. Yet, the properties governing the spatial dynamics of the astrocyte calcium signal remains poorly defined. Imaging subcellular responses of cortical astrocytes to sensory stimulation in mice, we show that sensory-evoked astrocyte calcium responses originated and remained localized in domains of the astrocytic arborization, but eventually propagated to the entire cell if a spatial threshold of >23% of the arborization being activated was surpassed. Using transgenic IP3R2-/- mice, we found that type-2 IP3 receptors were necessary for the generation of the astrocyte calcium surge. We finally show using in situ electrophysiological recordings that the spatial threshold of the astrocyte calcium signal consequently determined the gliotransmitter release. Present results reveal a fundamental property of astrocyte calcium physiology, i.e., a spatial threshold for the astrocyte intracellular calcium signal propagation, which depends on astrocyte intrinsic properties and governs the astrocyte integration of local synaptic activity and the subsequent neuromodulation.
Collapse
|
29
|
Hastings MH, Brancaccio M, Gonzalez-Aponte MF, Herzog ED. Circadian Rhythms and Astrocytes: The Good, the Bad, and the Ugly. Annu Rev Neurosci 2023; 46:123-143. [PMID: 36854316 PMCID: PMC10381027 DOI: 10.1146/annurev-neuro-100322-112249] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
This review explores the interface between circadian timekeeping and the regulation of brain function by astrocytes. Although astrocytes regulate neuronal activity across many time domains, their cell-autonomous circadian clocks exert a particular role in controlling longer-term oscillations of brain function: the maintenance of sleep states and the circadian ordering of sleep and wakefulness. This is most evident in the central circadian pacemaker, the suprachiasmatic nucleus, where the molecular clock of astrocytes suffices to drive daily cycles of neuronal activity and behavior. In Alzheimer's disease, sleep impairments accompany cognitive decline. In mouse models of the disease, circadian disturbances accelerate astroglial activation and other brain pathologies, suggesting that daily functions in astrocytes protect neuronal homeostasis. In brain cancer, treatment in the morning has been associated with prolonged survival, and gliomas have daily rhythms in gene expression and drug sensitivity. Thus, circadian time is fast becoming critical to elucidating reciprocal astrocytic-neuronal interactions in health and disease.
Collapse
Affiliation(s)
- Michael H Hastings
- Division of Neurobiology, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom;
| | - Marco Brancaccio
- UK Dementia Research Institute and Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Maria F Gonzalez-Aponte
- Department of Biology, Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, Missouri, USA;
| | - Erik D Herzog
- Department of Biology, Division of Biology and Biomedical Sciences, Washington University in St. Louis, St. Louis, Missouri, USA;
| |
Collapse
|
30
|
Stogsdill JA, Harwell CC, Goldman SA. Astrocytes as master modulators of neural networks: Synaptic functions and disease-associated dysfunction of astrocytes. Ann N Y Acad Sci 2023; 1525:41-60. [PMID: 37219367 DOI: 10.1111/nyas.15004] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Astrocytes are the most abundant glial cell type in the central nervous system and are essential to the development, plasticity, and maintenance of neural circuits. Astrocytes are heterogeneous, with their diversity rooted in developmental programs modulated by the local brain environment. Astrocytes play integral roles in regulating and coordinating neural activity extending far beyond their metabolic support of neurons and other brain cell phenotypes. Both gray and white matter astrocytes occupy critical functional niches capable of modulating brain physiology on time scales slower than synaptic activity but faster than those adaptive responses requiring a structural change or adaptive myelination. Given their many associations and functional roles, it is not surprising that astrocytic dysfunction has been causally implicated in a broad set of neurodegenerative and neuropsychiatric disorders. In this review, we focus on recent discoveries concerning the contributions of astrocytes to the function of neural networks, with a dual focus on the contribution of astrocytes to synaptic development and maturation, and on their role in supporting myelin integrity, and hence conduction and its regulation. We then address the emerging roles of astrocytic dysfunction in disease pathogenesis and on potential strategies for targeting these cells for therapeutic purposes.
Collapse
Affiliation(s)
| | - Corey C Harwell
- Department of Neurology, University of California San Francisco, San Francisco, California, USA
| | - Steven A Goldman
- Sana Biotechnology Inc., Cambridge, Massachusetts, USA
- Center for Translational Neuromedicine, University of Rochester, Rochester, New York, USA
- University of Copenhagen Faculty of Health and Medical Sciences, Copenhagen, Denmark
| |
Collapse
|
31
|
Semyachkina-Glushkovskaya O, Penzel T, Poluektov M, Fedosov I, Tzoy M, Terskov A, Blokhina I, Sidorov V, Kurths J. Phototherapy of Alzheimer's Disease: Photostimulation of Brain Lymphatics during Sleep: A Systematic Review. Int J Mol Sci 2023; 24:10946. [PMID: 37446135 DOI: 10.3390/ijms241310946] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/18/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023] Open
Abstract
The global number of people with Alzheimer's disease (AD) doubles every 5 years. It has been established that unless an effective treatment for AD is found, the incidence of AD will triple by 2060. However, pharmacological therapies for AD have failed to show effectiveness and safety. Therefore, the search for alternative methods for treating AD is an urgent problem in medicine. The lymphatic drainage and removal system of the brain (LDRSB) plays an important role in resistance to the progression of AD. The development of methods for augmentation of the LDRSB functions may contribute to progress in AD therapy. Photobiomodulation (PBM) is considered to be a non-pharmacological and safe approach for AD therapy. Here, we highlight the most recent and relevant studies of PBM for AD. We focus on emerging evidence that indicates the potential benefits of PBM during sleep for modulation of natural activation of the LDRSB at nighttime, providing effective removal of metabolites, including amyloid-β, from the brain, leading to reduced progression of AD. Our review creates a new niche in the therapy of brain diseases during sleep and sheds light on the development of smart sleep technologies for neurodegenerative diseases.
Collapse
Affiliation(s)
- Oxana Semyachkina-Glushkovskaya
- Department of Physics, Humboldt University, Newtonstrasse 15, 12489 Berlin, Germany
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
| | - Thomas Penzel
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
- Interdisziplinäres Schlafmedizinisches Zentrum, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Mikhail Poluektov
- Department of Nervous Diseases, Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya 2, Building 4, 119435 Moscow, Russia
| | - Ivan Fedosov
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
| | - Maria Tzoy
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
| | - Andrey Terskov
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
| | - Inna Blokhina
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
| | - Viktor Sidorov
- Company "Lazma" for Research and Production Enterprise of Laser Medical Equipment, Kuusinena Str. 11, 123308 Moscow, Russia
| | - Jürgen Kurths
- Department of Physics, Humboldt University, Newtonstrasse 15, 12489 Berlin, Germany
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
- Department of Complexity Science, Potsdam Institute for Climate Impact Research, Telegrafenberg A31, 14473 Potsdam, Germany
| |
Collapse
|
32
|
Que M, Li Y, Wang X, Zhan G, Luo X, Zhou Z. Role of astrocytes in sleep deprivation: accomplices, resisters, or bystanders? Front Cell Neurosci 2023; 17:1188306. [PMID: 37435045 PMCID: PMC10330732 DOI: 10.3389/fncel.2023.1188306] [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: 03/17/2023] [Accepted: 06/05/2023] [Indexed: 07/13/2023] Open
Abstract
Sleep plays an essential role in all studied animals with a nervous system. However, sleep deprivation leads to various pathological changes and neurobehavioral problems. Astrocytes are the most abundant cells in the brain and are involved in various important functions, including neurotransmitter and ion homeostasis, synaptic and neuronal modulation, and blood-brain barrier maintenance; furthermore, they are associated with numerous neurodegenerative diseases, pain, and mood disorders. Moreover, astrocytes are increasingly being recognized as vital contributors to the regulation of sleep-wake cycles, both locally and in specific neural circuits. In this review, we begin by describing the role of astrocytes in regulating sleep and circadian rhythms, focusing on: (i) neuronal activity; (ii) metabolism; (iii) the glymphatic system; (iv) neuroinflammation; and (v) astrocyte-microglia cross-talk. Moreover, we review the role of astrocytes in sleep deprivation comorbidities and sleep deprivation-related brain disorders. Finally, we discuss potential interventions targeting astrocytes to prevent or treat sleep deprivation-related brain disorders. Pursuing these questions would pave the way for a deeper understanding of the cellular and neural mechanisms underlying sleep deprivation-comorbid brain disorders.
Collapse
Affiliation(s)
- Mengxin Que
- Hubei Key Laboratory of Geriatric Anesthesia and Perioperative Brain Health, Department of Anesthesiology, Tongji Medical College, Wuhan Clinical Research Center for Geriatric Anesthesia, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Yujuan Li
- Hubei Key Laboratory of Geriatric Anesthesia and Perioperative Brain Health, Department of Anesthesiology, Tongji Medical College, Wuhan Clinical Research Center for Geriatric Anesthesia, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Xuan Wang
- Hubei Key Laboratory of Geriatric Anesthesia and Perioperative Brain Health, Department of Anesthesiology, Tongji Medical College, Wuhan Clinical Research Center for Geriatric Anesthesia, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Gaofeng Zhan
- Hubei Key Laboratory of Geriatric Anesthesia and Perioperative Brain Health, Department of Anesthesiology, Tongji Medical College, Wuhan Clinical Research Center for Geriatric Anesthesia, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoxiao Luo
- Department of Oncology, Tongji Medical College, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Zhiqiang Zhou
- Hubei Key Laboratory of Geriatric Anesthesia and Perioperative Brain Health, Department of Anesthesiology, Tongji Medical College, Wuhan Clinical Research Center for Geriatric Anesthesia, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| |
Collapse
|
33
|
Kanaya T, Ito R, Morizawa YM, Sasaki D, Yamao H, Ishikane H, Hiraoka Y, Tanaka K, Matsui K. Glial modulation of the parallel memory formation. Glia 2023. [PMID: 37364894 DOI: 10.1002/glia.24431] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 06/04/2023] [Accepted: 06/09/2023] [Indexed: 06/28/2023]
Abstract
Actions from glial cells could affect the readiness and efficacy of learning and memory. Using a mouse cerebellar-dependent horizontal optokinetic response motor learning paradigm, short-term memory (STM) formation during the online training period and long-term memory (LTM) formation during the offline rest period were studied. A large variability of online and offline learning efficacies was found. The early bloomers with booming STM often had a suppressed LTM formation and late bloomers with no apparent acute training effect often exhibited boosted offline learning performance. Anion channels containing LRRC8A are known to release glutamate. Conditional knockout of LRRC8A specifically in astrocytes including cerebellar Bergmann glia resulted in a complete loss of STM formation while the LTM formation during the rest period remained. Optogenetic manipulation of glial activity by channelrhodopsin-2 or archaerhodopsin-T (ArchT) during the online training resulted in enhancement or suppression of STM formation, respectively. STM and LTM are likely to be triggered simultaneously during online training, but LTM is expressed later during the offline period. STM appears to be volatile and the achievement during the online training is not handed over to LTM. In addition, we found that glial ArchT photoactivation during the rest period resulted in the augmentation of LTM formation. These data suggest that STM formation and LTM formation are parallel separate processes. Strategies to weigh more on the STM or the LTM could depend on the actions of the glial cells.
Collapse
Affiliation(s)
- Teppei Kanaya
- Super-Network Brain Physiology, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Ryo Ito
- Super-Network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Yosuke M Morizawa
- Super-Network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Daichi Sasaki
- Super-Network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Hiroki Yamao
- Super-Network Brain Physiology, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Hiroshi Ishikane
- Department of Psychology, Graduate School of Humanities, Senshu University, Kawasaki, Japan
| | - Yuichi Hiraoka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Kohichi Tanaka
- Laboratory of Molecular Neuroscience, Medical Research Institute (MRI), Tokyo Medical and Dental University (TMDU), Tokyo, 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
| |
Collapse
|
34
|
Gerstner JR, Flores CC, Lefton M, Rogers B, Davis CJ. FABP7: a glial integrator of sleep, circadian rhythms, plasticity, and metabolic function. Front Syst Neurosci 2023; 17:1212213. [PMID: 37404868 PMCID: PMC10315501 DOI: 10.3389/fnsys.2023.1212213] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 06/02/2023] [Indexed: 07/06/2023] Open
Abstract
Sleep and circadian rhythms are observed broadly throughout animal phyla and influence neural plasticity and cognitive function. However, the few phylogenetically conserved cellular and molecular pathways that are implicated in these processes are largely focused on neuronal cells. Research on these topics has traditionally segregated sleep homeostatic behavior from circadian rest-activity rhythms. Here we posit an alternative perspective, whereby mechanisms underlying the integration of sleep and circadian rhythms that affect behavioral state, plasticity, and cognition reside within glial cells. The brain-type fatty acid binding protein, FABP7, is part of a larger family of lipid chaperone proteins that regulate the subcellular trafficking of fatty acids for a wide range of cellular functions, including gene expression, growth, survival, inflammation, and metabolism. FABP7 is enriched in glial cells of the central nervous system and has been shown to be a clock-controlled gene implicated in sleep/wake regulation and cognitive processing. FABP7 is known to affect gene transcription, cellular outgrowth, and its subcellular localization in the fine perisynaptic astrocytic processes (PAPs) varies based on time-of-day. Future studies determining the effects of FABP7 on behavioral state- and circadian-dependent plasticity and cognitive processes, in addition to functional consequences on cellular and molecular mechanisms related to neural-glial interactions, lipid storage, and blood brain barrier integrity will be important for our knowledge of basic sleep function. Given the comorbidity of sleep disturbance with neurological disorders, these studies will also be important for our understanding of the etiology and pathophysiology of how these diseases affect or are affected by sleep.
Collapse
Affiliation(s)
- Jason R. Gerstner
- Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, United States
- Steve Gleason Institute for Neuroscience, Spokane, WA, United States
- Sleep and Performance Research Center, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, United States
| | - Carlos C. Flores
- Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, United States
| | - Micah Lefton
- Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, United States
| | - Brooke Rogers
- Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, United States
| | - Christopher J. Davis
- Department of Translational Medicine and Physiology, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, United States
- Steve Gleason Institute for Neuroscience, Spokane, WA, United States
- Sleep and Performance Research Center, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, United States
| |
Collapse
|
35
|
Cervetto C, Maura G, Guidolin D, Amato S, Ceccoli C, Agnati LF, Marcoli M. Striatal astrocytic A2A-D2 receptor-receptor interactions and their role in neuropsychiatric disorders. Neuropharmacology 2023:109636. [PMID: 37321323 DOI: 10.1016/j.neuropharm.2023.109636] [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: 03/30/2023] [Revised: 05/26/2023] [Accepted: 06/11/2023] [Indexed: 06/17/2023]
Abstract
It is now generally accepted that astrocytes are active players in synaptic transmission, so that a neurocentric perspective of the integrative signal communication in the central nervous system is shifting towards a neuro-astrocentric perspective. Astrocytes respond to synaptic activity, release chemical signals (gliotransmitters) and express neurotransmitter receptors (G protein-coupled and ionotropic receptors), thus behaving as co-actors with neurons in signal communication in the central nervous system. The ability of G protein-coupled receptors to physically interact through heteromerization, forming heteromers and receptor mosaics with new distinct signal recognition and transduction pathways, has been intensively studied at neuronal plasma membrane, and has changed the view of the integrative signal communication in the central nervous system. One of the best-known examples of receptor-receptor interaction through heteromerization, with relevant consequences for both the physiological and the pharmacological points of view, is given by adenosine A2A and dopamine D2 receptors on the plasma membrane of striatal neurons. Here we review evidence that native A2A and D2 receptors can interact through heteromerization at the plasma membrane of astrocytes as well. Astrocytic A2A-D2 heteromers were found able to control the release of glutamate from the striatal astrocyte processes. A2A-D2 heteromers on striatal astrocytes and astrocyte processes are discussed as far as their potential relevance in the control of glutamatergic transmission in striatum is concerned, including potential roles in glutamatergic transmission dysregulation in pathological conditions including schizophrenia or the Parkinson's disease.
Collapse
Affiliation(s)
- Chiara Cervetto
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy; Center for Promotion of 3Rs in Teaching and Research (Centro 3R), Pisa, Italy.
| | - Guido Maura
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy.
| | - Diego Guidolin
- Department of Neuroscience, University of Padova, Italy.
| | - Sarah Amato
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy.
| | - Cristina Ceccoli
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy.
| | - Luigi F Agnati
- Department of Biochemical, Metabolic Sciences and Neuroscience, University of Modena and Reggio Emilia, Modena, Italy.
| | - Manuela Marcoli
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy; Center for Promotion of 3Rs in Teaching and Research (Centro 3R), Pisa, Italy; Center of Excellence for Biomedical Research, University of Genova, Italy.
| |
Collapse
|
36
|
Purushotham SS, Buskila Y. Astrocytic modulation of neuronal signalling. FRONTIERS IN NETWORK PHYSIOLOGY 2023; 3:1205544. [PMID: 37332623 PMCID: PMC10269688 DOI: 10.3389/fnetp.2023.1205544] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/18/2023] [Indexed: 06/20/2023]
Abstract
Neuronal signalling is a key element in neuronal communication and is essential for the proper functioning of the CNS. Astrocytes, the most prominent glia in the brain play a key role in modulating neuronal signalling at the molecular, synaptic, cellular, and network levels. Over the past few decades, our knowledge about astrocytes and their functioning has evolved from considering them as merely a brain glue that provides structural support to neurons, to key communication elements. Astrocytes can regulate the activity of neurons by controlling the concentrations of ions and neurotransmitters in the extracellular milieu, as well as releasing chemicals and gliotransmitters that modulate neuronal activity. The aim of this review is to summarise the main processes through which astrocytes are modulating brain function. We will systematically distinguish between direct and indirect pathways in which astrocytes affect neuronal signalling at all levels. Lastly, we will summarize pathological conditions that arise once these signalling pathways are impaired focusing on neurodegeneration.
Collapse
Affiliation(s)
| | - Yossi Buskila
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
- The MARCS Institute, Western Sydney University, Campbelltown, NSW, Australia
| |
Collapse
|
37
|
Gau YTA, Hsu E, Cha J, Pak RW, Looger LL, Kang JU, Bergles DE. Multicore fiber optic imaging reveals that astrocyte calcium activity in the cerebral cortex is modulated by internal motivational state. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.18.541390. [PMID: 37292710 PMCID: PMC10245653 DOI: 10.1101/2023.05.18.541390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Astrocytes are a direct target of neuromodulators and can influence neuronal activity on broad spatial and temporal scales through their close proximity to synapses. However, our knowledge about how astrocytes are functionally recruited during different animal behaviors and their diverse effects on the CNS remains limited. To enable measurement of astrocyte activity patterns in vivo during normative behaviors, we developed a high-resolution, long working distance, multi-core fiber optic imaging platform that allows visualization of cortical astrocyte calcium transients through a cranial window in freely moving mice. Using this platform, we defined the spatiotemporal dynamics of astrocytes during diverse behaviors, ranging from circadian fluctuations to novelty exploration, showing that astrocyte activity patterns are more variable and less synchronous than apparent in head-immobilized imaging conditions. Although the activity of astrocytes in visual cortex was highly synchronized during quiescence to arousal transitions, individual astrocytes often exhibited distinct thresholds and activity patterns during explorative behaviors, in accordance with their molecular diversity, allowing temporal sequencing across the astrocyte network. Imaging astrocyte activity during self-initiated behaviors revealed that noradrenergic and cholinergic systems act synergistically to recruit astrocytes during state transitions associated with arousal and attention, which was profoundly modulated by internal state. The distinct activity patterns exhibited by astrocytes in the cerebral cortex may provide a means to vary their neuromodulatory influence in response to different behaviors and internal states.
Collapse
Affiliation(s)
- Yung-Tian A. Gau
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, United States
| | - Eric Hsu
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, United States
| | - Jaepyeong Cha
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, United States
| | - Rebecca W. Pak
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, United States
| | - Loren L. Looger
- Howard Hughes Medical Institute, Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, United States
| | - Jin U. Kang
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, United States
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, United States
| | - Dwight E. Bergles
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, United States
- Kavli Neuroscience Discovery Institute, Johns Hopkins University, Baltimore, MD 21205, United States
| |
Collapse
|
38
|
Barbay T, Pecchi E, Ducrocq M, Rouach N, Brocard F, Bos R. Astrocytic Kir4.1 channels regulate locomotion by orchestrating neuronal rhythmicity in the spinal network. Glia 2023; 71:1259-1277. [PMID: 36645018 DOI: 10.1002/glia.24337] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 12/22/2022] [Accepted: 01/02/2023] [Indexed: 01/17/2023]
Abstract
Neuronal rhythmogenesis in the spinal cord is correlated with variations in extracellular K+ levels ([K+ ]e ). Astrocytes play important role in [K+ ]e homeostasis and compute neuronal information. Yet it is unclear how neuronal oscillations are regulated by astrocytic K+ homeostasis. Here we identify the astrocytic inward-rectifying K+ channel Kir4.1 (a.k.a. Kcnj10) as a key molecular player for neuronal rhythmicity in the spinal central pattern generator (CPG). By combining two-photon calcium imaging with electrophysiology, immunohistochemistry and genetic tools, we report that astrocytes display Ca2+ transients before and during oscillations of neighboring neurons. Inhibition of astrocytic Ca2+ transients with BAPTA decreases the barium-sensitive Kir4.1 current responsible of K+ clearance. Finally, we show in mice that Kir4.1 knockdown in astrocytes progressively prevents neuronal oscillations and alters the locomotor pattern resulting in lower motor performances in challenging tasks. These data identify astroglial Kir4.1 channels as key regulators of neuronal rhythmogenesis in the CPG driving locomotion.
Collapse
Affiliation(s)
- Tony Barbay
- Aix Marseille Univ, CNRS, Institut de Neurosciences de la Timone (INT), UMR 7289, Marseille, France
| | - Emilie Pecchi
- Aix Marseille Univ, CNRS, Institut de Neurosciences de la Timone (INT), UMR 7289, Marseille, France
| | - Myriam Ducrocq
- Aix Marseille Univ, CNRS, Institut de Neurosciences de la Timone (INT), UMR 7289, Marseille, France
| | - Nathalie Rouach
- Center for Interdisciplinary Research in Biology, Collège de France, CNRS, INSERM, Labex Memolife, Université PSL, Paris, France
| | - Frédéric Brocard
- Aix Marseille Univ, CNRS, Institut de Neurosciences de la Timone (INT), UMR 7289, Marseille, France
| | - Rémi Bos
- Aix Marseille Univ, CNRS, Institut de Neurosciences de la Timone (INT), UMR 7289, Marseille, France
| |
Collapse
|
39
|
Lee YF, Russ AN, Zhao Q, Maci M, Miller MR, Hou SS, Algamal M, Zhao Z, Li H, Gelwan N, Gomperts SN, Araque A, Galea E, Bacskai BJ, Kastanenka KV. Optogenetic Targeting of Astrocytes Restores Slow Brain Rhythm Function and Slows Alzheimer's Disease Pathology. RESEARCH SQUARE 2023:rs.3.rs-2813056. [PMID: 37163040 PMCID: PMC10168443 DOI: 10.21203/rs.3.rs-2813056/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Patients with Alzheimer's disease (AD) exhibit non-rapid eye movement (NREM) sleep disturbances in addition to memory deficits. Disruption of NREM slow waves occurs early in the disease progression and is recapitulated in transgenic mouse models of beta-amyloidosis. However, the mechanisms underlying slow-wave disruptions remain unknown. Because astrocytes contribute to slow-wave activity, we used multiphoton microscopy and optogenetics to investigate whether they contribute to slow-wave disruptions in APP mice. The power but not the frequency of astrocytic calcium transients was reduced in APP mice compared to nontransgenic controls. Optogenetic activation of astrocytes at the endogenous frequency of slow waves restored slow-wave power, reduced amyloid deposition, prevented neuronal calcium elevations, and improved memory performance. Our findings revealed malfunction of the astrocytic network driving slow-wave disruptions. Thus, targeting astrocytes to restore circuit activity underlying sleep and memory disruptions in AD could ameliorate disease progression.
Collapse
Affiliation(s)
| | - Alyssa N Russ
- Massachusetts General Hospital, Harvard Medical School
| | - Qiuchen Zhao
- Massachusetts General Hospital, Harvard Medical School
| | - Megi Maci
- Massachusetts General Hospital, Harvard Medical School
| | | | - Steven S Hou
- Massachusetts General Hospital, Harvard Medical School
| | | | - Zhuoyang Zhao
- Massachusetts General Hospital, Harvard Medical School
| | - Hanyan Li
- Massachusetts General Hospital, Harvard Medical School
| | - Noah Gelwan
- Massachusetts General Hospital, Harvard Medical School
| | | | | | - Elena Galea
- Massachusetts General Hospital, Harvard Medical School
| | | | | |
Collapse
|
40
|
Tesler F, Linne ML, Destexhe A. Modeling the relationship between neuronal activity and the BOLD signal: contributions from astrocyte calcium dynamics. Sci Rep 2023; 13:6451. [PMID: 37081004 PMCID: PMC10119111 DOI: 10.1038/s41598-023-32618-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 03/30/2023] [Indexed: 04/22/2023] Open
Abstract
Functional magnetic resonance imaging relies on the coupling between neuronal and vascular activity, but the mechanisms behind this coupling are still under discussion. Recent experimental evidence suggests that calcium signaling may play a significant role in neurovascular coupling. However, it is still controversial where this calcium signal is located (in neurons or elsewhere), how it operates and how relevant is its role. In this paper we introduce a biologically plausible model of the neurovascular coupling and we show that calcium signaling in astrocytes can explain main aspects of the dynamics of the coupling. We find that calcium signaling can explain so-far unrelated features such as the linear and non-linear regimes, the negative vascular response (undershoot) and the emergence of a (calcium-driven) Hemodynamic Response Function. These features are reproduced here for the first time by a single model of the detailed neuronal-astrocyte-vascular pathway. Furthermore, we analyze how information is coded and transmitted from the neuronal to the vascular system and we predict that frequency modulation of astrocytic calcium dynamics plays a key role in this process. Finally, our work provides a framework to link neuronal activity to the BOLD signal, and vice-versa, where neuronal activity can be inferred from the BOLD signal. This opens new ways to link known alterations of astrocytic calcium signaling in neurodegenerative diseases (e.g. Alzheimer's and Parkinson's diseases) with detectable changes in the neurovascular coupling.
Collapse
Affiliation(s)
- Federico Tesler
- CNRS, Paris-Saclay Institute of Neuroscience (NeuroPSI), Paris-Saclay University, 91400, Saclay, France.
| | - Marja-Leena Linne
- Faculty of Medicine and Health Technology, Tampere University, 33720, Tampere, Finland
| | - Alain Destexhe
- CNRS, Paris-Saclay Institute of Neuroscience (NeuroPSI), Paris-Saclay University, 91400, Saclay, France
| |
Collapse
|
41
|
Wang F, Wang W, Gu S, Qi D, Smith NA, Peng W, Dong W, Yuan J, Zhao B, Mao Y, Cao P, Lu QR, Shapiro LA, Yi SS, Wu E, Huang JH. Distinct astrocytic modulatory roles in sensory transmission during sleep, wakefulness, and arousal states in freely moving mice. Nat Commun 2023; 14:2186. [PMID: 37069258 PMCID: PMC10110578 DOI: 10.1038/s41467-023-37974-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 04/04/2023] [Indexed: 04/19/2023] Open
Abstract
Despite extensive research on astrocytic Ca2+ in synaptic transmission, its contribution to the modulation of sensory transmission during different brain states remains largely unknown. Here, by using two-photon microscopy and whole-cell recordings, we show two distinct astrocytic Ca2+ signals in the murine barrel cortex: a small, long-lasting Ca2+ increase during sleep and a large, widespread but short-lasting Ca2+ spike when aroused. The large Ca2+ wave in aroused mice was inositol trisphosphate (IP3)-dependent, evoked by the locus coeruleus-norepinephrine system, and enhanced sensory input, contributing to reliable sensory transmission. However, the small Ca2+ transient was IP3-independent and contributed to decreased extracellular K+, hyperpolarization of the neurons, and suppression of sensory transmission. These events respond to different pharmacological inputs and contribute to distinct sleep and arousal functions by modulating the efficacy of sensory transmission. Together, our data demonstrate an important function for astrocytes in sleep and arousal states via astrocytic Ca2+ waves.
Collapse
Affiliation(s)
- Fushun Wang
- Institute of Brain and Psychological Sciences, Sichuan Normal University, Chengdu, Sichuan, 610060, China.
- Department of Neurosurgery, University of Rochester, Rochester, NY, 14643, USA.
| | - Wei Wang
- Institute of Brain and Psychological Sciences, Sichuan Normal University, Chengdu, Sichuan, 610060, China
- Department of Biology, Boston University, Boston, MA, 02215, USA
| | - Simeng Gu
- Institute of Brain and Psychological Sciences, Sichuan Normal University, Chengdu, Sichuan, 610060, China
- Department of Medical Psychology, Jiangsu University Medical School, Zhenjiang, 212013, China
| | - Dan Qi
- Department of Neurosurgery and Neuroscience Institute, Baylor Scott & White Health, Temple, TX, 76508, USA
| | - Nathan A Smith
- Department of Neurosurgery, University of Rochester, Rochester, NY, 14643, USA
- George Washington University School of Medicine and Health Sciences, Washington, DC, 20052, USA
- Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, Washington, DC, 20010, USA
| | - Weiguo Peng
- Institute of Brain and Psychological Sciences, Sichuan Normal University, Chengdu, Sichuan, 610060, China
| | - Wei Dong
- Key Laboratory of Medical Electrophysiology, Ministry of Education & Medical Electrophysiological Key Laboratory of Sichuan Province, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, 646000, China
| | - Jiajin Yuan
- Department of Neurosurgery, University of Rochester, Rochester, NY, 14643, USA
| | - Binbin Zhao
- Basic Medicine College, Hubei University of Chinese Medicine, Wuhan, China
| | - Ying Mao
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Peng Cao
- School of Psychology, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Qing Richard Lu
- Brain Tumor Center, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
| | - Lee A Shapiro
- Department of Neuroscience & Experimental Therapeutics, Texas A&M University, Bryan, TX, 77807, USA.
| | - S Stephen Yi
- Livestrong Cancer Institutes and Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA.
- Oden Institute for Computational Engineering and Sciences (ICES), The University of Texas at Austin, Austin, TX, 78712, USA.
- Department of Biomedical Engineering, Cockrell School of Engineering, The University of Texas at Austin, Austin, TX, 78712, USA.
| | - Erxi Wu
- Department of Neurosurgery and Neuroscience Institute, Baylor Scott & White Health, Temple, TX, 76508, USA.
- Livestrong Cancer Institutes and Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA.
- Texas A & M University Health Science Center, College Station, TX, 77843, USA.
| | - Jason H Huang
- Department of Neurosurgery and Neuroscience Institute, Baylor Scott & White Health, Temple, TX, 76508, USA.
- Texas A & M University Health Science Center, College Station, TX, 77843, USA.
- Department of Neurosurgery, Baylor College of Medicine, Temple, TX, 76508, USA.
| |
Collapse
|
42
|
Dzyubenko E, Hermann DM. Role of glia and extracellular matrix in controlling neuroplasticity in the central nervous system. Semin Immunopathol 2023:10.1007/s00281-023-00989-1. [PMID: 37052711 DOI: 10.1007/s00281-023-00989-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 03/24/2023] [Indexed: 04/14/2023]
Abstract
Neuronal plasticity is critical for the maintenance and modulation of brain activity. Emerging evidence indicates that glial cells actively shape neuroplasticity, allowing for highly flexible regulation of synaptic transmission, neuronal excitability, and network synchronization. Astrocytes regulate synaptogenesis, stabilize synaptic connectivity, and preserve the balance between excitation and inhibition in neuronal networks. Microglia, the brain-resident immune cells, continuously monitor and sculpt synapses, allowing for the remodeling of brain circuits. Glia-mediated neuroplasticity is driven by neuronal activity, controlled by a plethora of feedback signaling mechanisms and crucially involves extracellular matrix remodeling in the central nervous system. This review summarizes the key findings considering neurotransmission regulation and metabolic support by astrocyte-neuronal networks, and synaptic remodeling mediated by microglia. Novel data indicate that astrocytes and microglia are pivotal for controlling brain function, indicating the necessity to rethink neurocentric neuroplasticity views.
Collapse
Affiliation(s)
- Egor Dzyubenko
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, Hufelandstr. 55, 45147, Essen, Germany.
| | - Dirk M Hermann
- Department of Neurology and Center for Translational Neuro- and Behavioral Sciences (C-TNBS), University Hospital Essen, Hufelandstr. 55, 45147, Essen, Germany.
| |
Collapse
|
43
|
Delepine C, Shih J, Li K, Gaudeaux P, Sur M. Differential Effects of Astrocyte Manipulations on Learned Motor Behavior and Neuronal Ensembles in the Motor Cortex. J Neurosci 2023; 43:2696-2713. [PMID: 36894315 PMCID: PMC10089242 DOI: 10.1523/jneurosci.1982-22.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 01/31/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023] Open
Abstract
Although motor cortex is crucial for learning precise and reliable movements, whether and how astrocytes contribute to its plasticity and function during motor learning is unknown. Here, we report that astrocyte-specific manipulations in primary motor cortex (M1) during a lever push task alter motor learning and execution, as well as the underlying neuronal population coding. Mice that express decreased levels of the astrocyte glutamate transporter 1 (GLT1) show impaired and variable movement trajectories, whereas mice with increased astrocyte Gq signaling show decreased performance rates, delayed response times, and impaired trajectories. In both groups, which include male and female mice, M1 neurons have altered interneuronal correlations and impaired population representations of task parameters, including response time and movement trajectories. RNA sequencing further supports a role for M1 astrocytes in motor learning and shows changes in astrocytic expression of glutamate transporter genes, GABA transporter genes, and extracellular matrix protein genes in mice that have acquired this learned behavior. Thus, astrocytes coordinate M1 neuronal activity during motor learning, and our results suggest that this contributes to learned movement execution and dexterity through mechanisms that include regulation of neurotransmitter transport and calcium signaling.SIGNIFICANCE STATEMENT We demonstrate for the first time that in the M1 of mice, astrocyte function is critical for coordinating neuronal population activity during motor learning. We demonstrate that knockdown of astrocyte glutamate transporter GLT1 affects specific components of learning, such as smooth trajectory formation. Altering astrocyte calcium signaling by activation of Gq-DREADD upregulates GLT1 and affects other components of learning, such as response rates and reaction times as well as trajectory smoothness. In both manipulations, neuronal activity in motor cortex is dysregulated, but in different ways. Thus, astrocytes have a crucial role in motor learning via their influence on motor cortex neurons, and they do so by mechanisms that include regulation of glutamate transport and calcium signals.
Collapse
Affiliation(s)
- Chloe Delepine
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Jennifer Shih
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Keji Li
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Pierre Gaudeaux
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Mriganka Sur
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Simons Center for the Social Brain, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| |
Collapse
|
44
|
Baraibar AM, Belisle L, Marsicano G, Matute C, Mato S, Araque A, Kofuji P. Spatial organization of neuron-astrocyte interactions in the somatosensory cortex. Cereb Cortex 2023; 33:4498-4511. [PMID: 36124663 PMCID: PMC10110431 DOI: 10.1093/cercor/bhac357] [Citation(s) in RCA: 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: 05/09/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/15/2022] Open
Abstract
Microcircuits in the neocortex are functionally organized along layers and columns, which are the fundamental modules of cortical information processing. While the function of cortical microcircuits has focused on neuronal elements, much less is known about the functional organization of astrocytes and their bidirectional interaction with neurons. Here, we show that Cannabinoid type 1 receptor (CB1R)-mediated astrocyte activation by neuron-released endocannabinoids elevate astrocyte Ca2+ levels, stimulate ATP/adenosine release as gliotransmitters, and transiently depress synaptic transmission in layer 5 pyramidal neurons at relatively distant synapses (˃20 μm) from the stimulated neuron. This astrocyte-mediated heteroneuronal synaptic depression occurred between pyramidal neurons within a cortical column and was absent in neurons belonging to adjacent cortical columns. Moreover, this form of heteroneuronal synaptic depression occurs between neurons located in particular layers, following a specific connectivity pattern that depends on a layer-specific neuron-to-astrocyte signaling. These results unravel the existence of astrocyte-mediated nonsynaptic communication between cortical neurons and that this communication is column- and layer-specific, which adds further complexity to the intercellular signaling processes in the neocortex.
Collapse
Affiliation(s)
- Andrés M Baraibar
- Department of Neuroscience, University of Minnesota. Minneapolis, MN, USA
- Department of Neurosciences, University of the Basque Country UPV/EHU, Leioa, Spain
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Biocruces Bizkaia, Baracaldo, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Lindsey Belisle
- Department of Neuroscience, University of Minnesota. Minneapolis, MN, USA
| | - Giovanni Marsicano
- INSERM, U862 NeuroCentre Magendie, Endocannabinoids and Neuroadaptation, Bordeaux, France
- NeuroCentre Magendie, Endocannabinoids and Neuroadaptation, University of Bordeaux, Bordeaux, France
| | - Carlos Matute
- Department of Neurosciences, University of the Basque Country UPV/EHU, Leioa, Spain
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Susana Mato
- Department of Neurosciences, University of the Basque Country UPV/EHU, Leioa, Spain
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Biocruces Bizkaia, Baracaldo, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota. Minneapolis, MN, USA
| | - Paulo Kofuji
- Department of Neuroscience, University of Minnesota. Minneapolis, MN, USA
| |
Collapse
|
45
|
Lezmy J. How astrocytic ATP shapes neuronal activity and brain circuits. Curr Opin Neurobiol 2023; 79:102685. [PMID: 36746109 DOI: 10.1016/j.conb.2023.102685] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 01/03/2023] [Accepted: 01/06/2023] [Indexed: 02/06/2023]
Abstract
Astrocytes play a key role in processing information at synapses, by controlling synapse formation, modulating synapse strength and terminating neurotransmitter action. They release ATP to shape brain activity but it is unclear how, as astrocyte processes contact many targets and ATP-mediated effects are diverse and numerous. Here, I review recent studies showing how astrocytic ATP modulates cellular mechanisms in nearby neurons and glia in the grey and white matter, how it affects signal transmission in these areas, and how it modulates behavioural outputs. I attempt to provide a flowchart of astrocytic ATP signalling, showing that it tends to inhibit neural circuits to match energy demands.
Collapse
Affiliation(s)
- Jonathan Lezmy
- Department of Neuroscience, Physiology & Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
| |
Collapse
|
46
|
Reitman ME, Tse V, Mi X, Willoughby DD, Peinado A, Aivazidis A, Myagmar BE, Simpson PC, Bayraktar OA, Yu G, Poskanzer KE. Norepinephrine links astrocytic activity to regulation of cortical state. Nat Neurosci 2023; 26:579-593. [PMID: 36997759 PMCID: PMC10089924 DOI: 10.1038/s41593-023-01284-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 02/14/2023] [Indexed: 04/01/2023]
Abstract
Cortical state, defined by population-level neuronal activity patterns, determines sensory perception. While arousal-associated neuromodulators-including norepinephrine (NE)-reduce cortical synchrony, how the cortex resynchronizes remains unknown. Furthermore, general mechanisms regulating cortical synchrony in the wake state are poorly understood. Using in vivo imaging and electrophysiology in mouse visual cortex, we describe a critical role for cortical astrocytes in circuit resynchronization. We characterize astrocytes' calcium responses to changes in behavioral arousal and NE, and show that astrocytes signal when arousal-driven neuronal activity is reduced and bi-hemispheric cortical synchrony is increased. Using in vivo pharmacology, we uncover a paradoxical, synchronizing response to Adra1a receptor stimulation. We reconcile these results by demonstrating that astrocyte-specific deletion of Adra1a enhances arousal-driven neuronal activity, while impairing arousal-related cortical synchrony. Our findings demonstrate that astrocytic NE signaling acts as a distinct neuromodulatory pathway, regulating cortical state and linking arousal-associated desynchrony to cortical circuit resynchronization.
Collapse
Affiliation(s)
- Michael E Reitman
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Vincent Tse
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Xuelong Mi
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA, USA
| | - Drew D Willoughby
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | - Alba Peinado
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA
| | | | - Bat-Erdene Myagmar
- Department of Medicine and Research Service, San Francisco Veterans Affairs Medical Center and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Paul C Simpson
- Department of Medicine and Research Service, San Francisco Veterans Affairs Medical Center and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
| | | | - Guoqiang Yu
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA, USA
| | - Kira E Poskanzer
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA, USA.
- Department of Biochemistry & Biophysics, University of California, San Francisco, San Francisco, CA, USA.
- Kavli Institute for Fundamental Neuroscience, San Francisco, CA, USA.
| |
Collapse
|
47
|
Hess EM, Kassel SN, Simandl G, Raddatz N, Maunze B, Hurley MM, Grzybowski M, Klotz J, Geurts A, Liu QS, Choi S, Twining RC, Baker DA. Genetic Disruption of System xc-Mediated Glutamate Release from Astrocytes Increases Negative-Outcome Behaviors While Preserving Basic Brain Function in Rat. J Neurosci 2023; 43:2349-2361. [PMID: 36788029 PMCID: PMC10072291 DOI: 10.1523/jneurosci.1525-22.2023] [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: 08/09/2022] [Revised: 01/04/2023] [Accepted: 02/02/2023] [Indexed: 02/16/2023] Open
Abstract
The importance of neuronal glutamate to synaptic transmission throughout the brain illustrates the immense therapeutic potential and safety risks of targeting this system. Astrocytes also release glutamate, the clinical relevance of which is unknown as the range of brain functions reliant on signaling from these cells hasn't been fully established. Here, we investigated system xc- (Sxc), which is a glutamate release mechanism with an in vivo rodent expression pattern that is restricted to astrocytes. As most animals do not express Sxc, we first compared the expression and sequence of the obligatory Sxc subunit xCT among major classes of vertebrate species. We found xCT to be ubiquitously expressed and under significant negative selective pressure. Hence, Sxc likely confers important advantages to vertebrate brain function that may promote biological fitness. Next, we assessed brain function in male genetically modified rats (MSxc) created to eliminate Sxc activity. Unlike other glutamatergic mechanisms, eliminating Sxc activity was not lethal and didn't alter growth patterns, telemetry measures of basic health, locomotor activity, or behaviors reliant on simple learning. However, MSxc rats exhibited deficits in tasks used to assess cognitive behavioral control. In a pavlovian conditioned approach, MSxc rats approached a food-predicted cue more frequently than WT rats, even when this response was punished. In attentional set shifting, MSxc rats displayed cognitive inflexibility because of an increased frequency of perseverative errors. MSxc rats also displayed heightened cocaine-primed drug seeking. Hence, a loss of Sxc-activity appears to weaken control over nonreinforced or negative-outcome behaviors without altering basic brain function.SIGNIFICANCE STATEMENT Glutamate is essential to synaptic activity throughout the brain, which illustrates immense therapeutic potential and risk. Notably, glutamatergic mechanisms are expressed by most types of brain cells. Hence, glutamate likely encodes multiple forms of intercellular signaling. Here, we hypothesized that the selective manipulation of astrocyte to neuron signaling would alter cognition without producing widespread brain impairments. First, we eliminated activity of the astrocytic glutamate release mechanism, Sxc, in rat. This impaired cognitive flexibility and increased expression of perseverative, maladaptive behaviors. Notably, eliminating Sxc activity did not alter metrics of health or noncognitive brain function. These data add to recent evidence that the brain expresses cognition-specific molecular mechanisms that could lead to highly precise, safe medications for impaired cognition.
Collapse
Affiliation(s)
- Evan M Hess
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | - Sara N Kassel
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | - Gregory Simandl
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | - Nicholas Raddatz
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | - Brian Maunze
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | - Matthew M Hurley
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | | | | | | | - Qing-Song Liu
- Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - SuJean Choi
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | - Robert C Twining
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin 53233
| | - David A Baker
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin 53233
| |
Collapse
|
48
|
Manninen T, Aćimović J, Linne ML. Analysis of Network Models with Neuron-Astrocyte Interactions. Neuroinformatics 2023; 21:375-406. [PMID: 36959372 PMCID: PMC10085960 DOI: 10.1007/s12021-023-09622-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2023] [Indexed: 03/25/2023]
Abstract
Neural networks, composed of many neurons and governed by complex interactions between them, are a widely accepted formalism for modeling and exploring global dynamics and emergent properties in brain systems. In the past decades, experimental evidence of computationally relevant neuron-astrocyte interactions, as well as the astrocytic modulation of global neural dynamics, have accumulated. These findings motivated advances in computational glioscience and inspired several models integrating mechanisms of neuron-astrocyte interactions into the standard neural network formalism. These models were developed to study, for example, synchronization, information transfer, synaptic plasticity, and hyperexcitability, as well as classification tasks and hardware implementations. We here focus on network models of at least two neurons interacting bidirectionally with at least two astrocytes that include explicitly modeled astrocytic calcium dynamics. In this study, we analyze the evolution of these models and the biophysical, biochemical, cellular, and network mechanisms used to construct them. Based on our analysis, we propose how to systematically describe and categorize interaction schemes between cells in neuron-astrocyte networks. We additionally study the models in view of the existing experimental data and present future perspectives. Our analysis is an important first step towards understanding astrocytic contribution to brain functions. However, more advances are needed to collect comprehensive data about astrocyte morphology and physiology in vivo and to better integrate them in data-driven computational models. Broadening the discussion about theoretical approaches and expanding the computational tools is necessary to better understand astrocytes' roles in brain functions.
Collapse
Affiliation(s)
- Tiina Manninen
- Faculty of Medicine and Health Technology, Tampere University, Korkeakoulunkatu 3, FI-33720, Tampere, Finland.
| | - Jugoslava Aćimović
- Faculty of Medicine and Health Technology, Tampere University, Korkeakoulunkatu 3, FI-33720, Tampere, Finland
| | - Marja-Leena Linne
- Faculty of Medicine and Health Technology, Tampere University, Korkeakoulunkatu 3, FI-33720, Tampere, Finland.
| |
Collapse
|
49
|
Lawson J, LaVancher E, DeAlmeida M, Black BJ. Electrically-evoked oscillating calcium transients in mono- and co-cultures of iPSC glia and sensory neurons. Front Cell Neurosci 2023; 17:1094070. [PMID: 37006467 PMCID: PMC10060658 DOI: 10.3389/fncel.2023.1094070] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 02/17/2023] [Indexed: 03/18/2023] Open
Abstract
Activated glia are known to exhibit either neuroprotective or neurodegenerative effects, depending on their phenotype, while participating in chronic pain regulation. Until recently, it has been believed that satellite glial cells and astrocytes are electrically slight and process stimuli only through intracellular calcium flux that triggers downstream signaling mechanisms. Though glia do not exhibit action potentials, they do express both voltage- and ligand-gated ion channels that facilitate measurable calcium transients, a measure of their own phenotypic excitability, and support and modulate sensory neuron excitability through ion buffering and secretion of excitatory or inhibitory neuropeptides (i.e., paracrine signaling). We recently developed a model of acute and chronic nociception using co-cultures of iPSC sensory neurons (SN) and spinal astrocytes on microelectrode arrays (MEAs). Until recently, only neuronal extracellular activity has been recorded using MEAs with a high signal-to-noise ratio and in a non-invasive manner. Unfortunately, this method has limited compatibility with simultaneous calcium transient imaging techniques, which is the most common method for monitoring the phenotypic activity of astrocytes. Moreover, both dye-based and genetically encoded calcium indicator imaging rely on calcium chelation, affecting the culture’s long-term physiology. Therefore, it would be ideal to allow continuous and simultaneous direct phenotypic monitoring of both SNs and astrocytes in a high-to-moderate throughput non-invasive manner and would significantly advance the field of electrophysiology. Here, we characterize astrocytic oscillating calcium transients (OCa2+Ts) in mono- and co-cultures of iPSC astrocytes as well as iPSC SN-astrocyte co-cultures on 48 well plate MEAs. We demonstrate that astrocytes exhibit OCa2+Ts in an electrical stimulus amplitude- and duration-dependent manner. We show that OCa2+Ts can be pharmacologically inhibited with the gap junction antagonist, carbenoxolone (100 μM). Most importantly, we demonstrate that both neurons and glia can be phenotypically characterized in real time, repeatedly, over the duration of the culture. In total, our findings suggest that calcium transients in glial populations may serve as a stand-alone or supplemental screening technique for identifying potential analgesics or compounds targeting other glia-mediated pathologies.
Collapse
|
50
|
Astroglial CB1 receptors, energy metabolism, and gliotransmission: an integrated signaling system? Essays Biochem 2023; 67:49-61. [PMID: 36645029 DOI: 10.1042/ebc20220089] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 12/06/2022] [Accepted: 12/07/2022] [Indexed: 01/17/2023]
Abstract
Astrocytes are key players in brain homeostasis and function. During the last years, several studies have cemented this notion by showing that these cells respond to neuronal signals and, via the release of molecules that modulate and support synaptic activity (gliotransmission) participates in the functions of the so-called tripartite synapse. Thus, besides their established control of brain metabolism, astrocytes can also actively control synaptic activity and behavior. Among the signaling pathways that shape the functions of astrocyte, the cannabinoid type-1 (CB1) receptor is emerging as a critical player in the control of both gliotransmission and the metabolic cooperation between astrocytes and neurons. In the present short review, we describe known and newly discovered properties of the astroglial CB1 receptors and their role in modulating brain function and behavior. Based on this evidence, we finally discuss how the functions and mode of actions of astrocyte CB1 receptors might represent a clear example of the inextricable relationship between energy metabolism and gliotransmission. These tight interactions will need to be taken into account for future research in astrocyte functions and call for a reinforcement of the theoretical and experimental bridges between studies on metabolic and synaptic functions of astrocytes.
Collapse
|