1
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Borrus DS, Stettler MK, Grover CJ, Kalajian EJ, Gu J, Conradi Smith GD, Del Negro CA. Inspiratory and sigh breathing rhythms depend on distinct cellular signalling mechanisms in the preBötzinger complex. J Physiol 2024; 602:809-834. [PMID: 38353596 PMCID: PMC10940220 DOI: 10.1113/jp285582] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 12/21/2023] [Indexed: 02/21/2024] Open
Abstract
Breathing behaviour involves the generation of normal breaths (eupnoea) on a timescale of seconds and sigh breaths on the order of minutes. Both rhythms emerge in tandem from a single brainstem site, but whether and how a single cell population can generate two disparate rhythms remains unclear. We posit that recurrent synaptic excitation in concert with synaptic depression and cellular refractoriness gives rise to the eupnoea rhythm, whereas an intracellular calcium oscillation that is slower by orders of magnitude gives rise to the sigh rhythm. A mathematical model capturing these dynamics simultaneously generates eupnoea and sigh rhythms with disparate frequencies, which can be separately regulated by physiological parameters. We experimentally validated key model predictions regarding intracellular calcium signalling. All vertebrate brains feature a network oscillator that drives the breathing pump for regular respiration. However, in air-breathing mammals with compliant lungs susceptible to collapse, the breathing rhythmogenic network may have refashioned ubiquitous intracellular signalling systems to produce a second slower rhythm (for sighs) that prevents atelectasis without impeding eupnoea. KEY POINTS: A simplified activity-based model of the preBötC generates inspiratory and sigh rhythms from a single neuron population. Inspiration is attributable to a canonical excitatory network oscillator mechanism. Sigh emerges from intracellular calcium signalling. The model predicts that perturbations of calcium uptake and release across the endoplasmic reticulum counterintuitively accelerate and decelerate sigh rhythmicity, respectively, which was experimentally validated. Vertebrate evolution may have adapted existing intracellular signalling mechanisms to produce slow oscillations needed to optimize pulmonary function in mammals.
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Affiliation(s)
- Daniel S. Borrus
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
| | - Marco K. Stettler
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
| | - Cameron J. Grover
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
| | - Eva J. Kalajian
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
| | - Jeffrey Gu
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
| | - Gregory D. Conradi Smith
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
- Conradi Smith and Del Negro contributed equally
| | - Christopher A. Del Negro
- Applied Science and Neuroscience, William & Mary, Williamsburg, VA 23185
- Conradi Smith and Del Negro contributed equally
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2
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Onimaru H, Fukushi I, Ikeda K, Yazawa I, Takeda K, Okada Y, Izumizaki M. Cell Responses of the Ventrolateral Medulla to PAR1 Activation and Changes in Respiratory Rhythm in Newborn Rat En Bloc Brainstem-Spinal Cord Preparations. Neuroscience 2023; 528:89-101. [PMID: 37557948 DOI: 10.1016/j.neuroscience.2023.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/29/2023] [Accepted: 08/01/2023] [Indexed: 08/11/2023]
Abstract
Proteinase-activated receptor-1 (PAR1) is expressed in astrocytes of various brain regions, and its activation is involved in the modulation of neuronal activity. Here, we report effects of PAR1 selective agonist TFLLR on respiratory rhythm generation in brainstem-spinal cord preparations. Preparations were isolated from newborn rats (P0-P4) under deep isoflurane anesthesia and were transversely cut at the rostral medulla. Preparations were superfused with artificial cerebrospinal fluid (25-26 °C), and inspiratory C4 ventral root activity was monitored. The responses to TFLLR of cells close to the cut surface were detected by calcium imaging or membrane potential recordings. Application of 10 μM TFLLR (4 min) induced a rapid and transient increase of calcium signal in cells of the ventrolateral respiratory regions of the medulla. More than 88% of responding cells (223/254 cells from 13 preparations) were also activated by low (0.2 mM) K+ solution, suggesting that they were astrocytes. Immunohistochemical examination demonstrated that PAR1 was expressed on many astrocytes. Respiratory-related neurons in the medulla were transiently hyperpolarized (-1.8 mV) during 10 μM TFLLR application, followed by weak membrane depolarization after washout. C4 burst rate decreased transiently in response to application of TFLLR, followed by a slight increase. The inhibitory effect was partially blocked by 50 μM theophylline. In conclusion, activation of astrocytes via PAR1 resulted in a decrease of inspiratory C4 burst rate in association with transient hyperpolarization of respiratory-related neurons. After washout, slow and weak excitatory responses appeared. Adenosine may be partially involved in the inhibitory effect of PAR1 activation.
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Affiliation(s)
- Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, Tokyo, Japan.
| | - Isato Fukushi
- Faculty of Health Sciences, Aomori University of Health and Welfare, Aomori, Japan; Clinical Research Center, Murayama Medical Center, Musashimurayama, Tokyo, Japan
| | - Keiko Ikeda
- Department of Oral Physiology, Showa University School of Dentistry, Tokyo, Japan
| | - Itaru Yazawa
- Department of Food & Nutrition, Kyushu Nutrition Welfare University, Fukuoka, Japan
| | - Kotaro Takeda
- Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, Toyoake, Japan
| | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Tokyo, Japan
| | - Masahiko Izumizaki
- Department of Physiology, Showa University School of Medicine, Tokyo, Japan
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3
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Tacke C, Bischoff AM, Harb A, Vafadari B, Hülsmann S. Fiber optical imaging of astroglial calcium signaling in the respiratory network in the working heart brainstem preparation. Front Physiol 2023; 14:1237376. [PMID: 37693007 PMCID: PMC10484401 DOI: 10.3389/fphys.2023.1237376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 08/10/2023] [Indexed: 09/12/2023] Open
Abstract
The neuronal activity in the respiratory network strongly depends on a variety of different neuromodulators. Given the essential role of astrocytes in stabilizing respiratory network activity generated by neurons in the preBötzinger complex (preBötC), our aim was to investigate astrocytic calcium signaling in the working heart brainstem preparation using fiber-optical imaging. By using transgenic mice that express GCaMP6s specifically in astrocytes, we successfully recorded astrocytic calcium signals in response to norepinephrine from individual astrocytes.
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Affiliation(s)
| | | | | | | | - Swen Hülsmann
- Department of Anesthesiology, University Medical Center Göttingen, Göttingen, Germany
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4
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Delgado L, Navarrete M. Shining the Light on Astrocytic Ensembles. Cells 2023; 12:1253. [PMID: 37174653 PMCID: PMC10177371 DOI: 10.3390/cells12091253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 04/22/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
While neurons have traditionally been considered the primary players in information processing, the role of astrocytes in this mechanism has largely been overlooked due to experimental constraints. In this review, we propose that astrocytic ensembles are active working groups that contribute significantly to animal conduct and suggest that studying the maps of these ensembles in conjunction with neurons is crucial for a more comprehensive understanding of behavior. We also discuss available methods for studying astrocytes and argue that these ensembles, complementarily with neurons, code and integrate complex behaviors, potentially specializing in concrete functions.
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Affiliation(s)
| | - Marta Navarrete
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), 28002 Madrid, Spain
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5
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Tacke C, Bischoff AM, Harb A, Vafadari B, Hülsmann S. Angiotensin II increases respiratory rhythmic activity in the preBötzinger complex without inducing astroglial calcium signaling. Front Cell Neurosci 2023; 17:1111263. [PMID: 36816850 PMCID: PMC9932970 DOI: 10.3389/fncel.2023.1111263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
Angiotensin II (Ang II) is the primary modulator of the renin-angiotensin system and has been widely studied for its effect on the cardiovascular system. While a few studies have also indicated an involvement of Ang II in the regulation of breathing, very little is known in this regard and its effect on brainstem respiratory regions such as the preBötzinger complex (preBötC), the kernel for inspiratory rhythm generation, has not been investigated yet. This study reports that Ang II temporarily increases phrenic nerve activity in the working heart-brainstem preparation, indicating higher central respiratory drive. Previous studies have shown that the carotid body is involved in mediating this effect and we revealed that the preBötC also plays a part, using acute slices of the brainstem. It appears that Ang II is increasing the respiratory drive in an AT1R-dependent manner by optimizing the interaction of inhibitory and excitatory neurons of the preBötC. Thus, Ang II-mediated effects on the preBötC are potentially involved in dysregulating breathing in patients with acute lung injury.
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6
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Wiese BM, Alvarez Reyes A, Vanderah TW, Largent-Milnes TM. The endocannabinoid system and breathing. Front Neurosci 2023; 17:1126004. [PMID: 37144090 PMCID: PMC10153446 DOI: 10.3389/fnins.2023.1126004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 03/16/2023] [Indexed: 05/06/2023] Open
Abstract
Recent changes in cannabis accessibility have provided adjunct therapies for patients across numerous disease states and highlights the urgency in understanding how cannabinoids and the endocannabinoid (EC) system interact with other physiological structures. The EC system plays a critical and modulatory role in respiratory homeostasis and pulmonary functionality. Respiratory control begins in the brainstem without peripheral input, and coordinates the preBötzinger complex, a component of the ventral respiratory group that interacts with the dorsal respiratory group to synchronize burstlet activity and drive inspiration. An additional rhythm generator: the retrotrapezoid nucleus/parafacial respiratory group drives active expiration during conditions of exercise or high CO2. Combined with the feedback information from the periphery: through chemo- and baroreceptors including the carotid bodies, the cranial nerves, stretch of the diaphragm and intercostal muscles, lung tissue, and immune cells, and the cranial nerves, our respiratory system can fine tune motor outputs that ensure we have the oxygen necessary to survive and can expel the CO2 waste we produce, and every aspect of this process can be influenced by the EC system. The expansion in cannabis access and potential therapeutic benefits, it is essential that investigations continue to uncover the underpinnings and mechanistic workings of the EC system. It is imperative to understand the impact cannabis, and exogenous cannabinoids have on these physiological systems, and how some of these compounds can mitigate respiratory depression when combined with opioids or other medicinal therapies. This review highlights the respiratory system from the perspective of central versus peripheral respiratory functionality and how these behaviors can be influenced by the EC system. This review will summarize the literature available on organic and synthetic cannabinoids in breathing and how that has shaped our understanding of the role of the EC system in respiratory homeostasis. Finally, we look at some potential future therapeutic applications the EC system has to offer for the treatment of respiratory diseases and a possible role in expanding the safety profile of opioid therapies while preventing future opioid overdose fatalities that result from respiratory arrest or persistent apnea.
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Affiliation(s)
- Beth M. Wiese
- Department of Pharmacology, University of Arizona, Tucson, AZ, United States
| | - Angelica Alvarez Reyes
- Department of Pharmacology, University of Arizona, Tucson, AZ, United States
- College of Medicine, University of Arizona, Tucson, AZ, United States
| | - Todd W. Vanderah
- Department of Pharmacology, University of Arizona, Tucson, AZ, United States
| | - Tally M. Largent-Milnes
- Department of Pharmacology, University of Arizona, Tucson, AZ, United States
- *Correspondence: Tally M. Largent-Milnes,
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7
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Fukushi I, Ikeda K, Takeda K, Yoshizawa M, Kono Y, Hasebe Y, Pokorski M, Okada Y. Minocycline prevents hypoxia-induced seizures. Front Neural Circuits 2023; 17:1006424. [PMID: 37035503 PMCID: PMC10073501 DOI: 10.3389/fncir.2023.1006424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 02/27/2023] [Indexed: 04/11/2023] Open
Abstract
Severe hypoxia induces seizures, which reduces ventilation and worsens the ictal state. It is a health threat to patients, particularly those with underlying hypoxic respiratory pathologies, which may be conducive to a sudden unexpected death in epilepsy (SUDEP). Recent studies provide evidence that brain microglia are involved with both respiratory and ictal processes. Here, we investigated the hypothesis that microglia could interact with hypoxia-induced seizures. To this end, we recorded electroencephalogram (EEG) and acute ventilatory responses to hypoxia (5% O2 in N2) in conscious, spontaneously breathing adult mice. We compared control vehicle pre-treated animals with those pre-treated with minocycline, an inhibitory modulator of microglial activation. First, we histologically confirmed that hypoxia activates microglia and that pre-treatment with minocycline blocks hypoxia-induced microglial activation. Then, we analyzed the effects of minocycline pre-treatment on ventilatory responses to hypoxia by plethysmography. Minocycline alone failed to affect respiratory variables in room air or the initial respiratory augmentation in hypoxia. The comparative results showed that hypoxia caused seizures, which were accompanied by the late phase ventilatory suppression in all but one minocycline pre-treated mouse. Compared to the vehicle pre-treated, the minocycline pre-treated mice showed a delayed occurrence of seizures. Further, minocycline pre-treated mice tended to resist post-ictal respiratory arrest. These results suggest that microglia are conducive to seizure activity in severe hypoxia. Thus, inhibition of microglial activation may help suppress or prevent hypoxia-induced ictal episodes.
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Affiliation(s)
- Isato Fukushi
- Faculty of Health Sciences, Aomori University of Health and Welfare, Aomori, Japan
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- *Correspondence: Isato Fukushi
| | - Keiko Ikeda
- Homeostatic Mechanism Research Unit, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Kotaro Takeda
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, Toyoake, Japan
| | - Masashi Yoshizawa
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Chuo, Japan
| | - Yosuke Kono
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Chuo, Japan
| | - Yohei Hasebe
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Chuo, Japan
| | | | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
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8
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Mikami Y, Iizuka M, Onimaru H, Izumizaki M. Glycine and GABAA receptors suppressively regulate the inspiratory-related calcium rise in the thoracic inspiratory cells of the neonatal rat. J Physiol Sci 2022; 72:24. [PMID: 36192688 DOI: 10.1186/s12576-022-00850-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 09/27/2022] [Indexed: 11/10/2022]
Abstract
We previously demonstrated that in an isolated brainstem-spinal cord preparation from neonatal rats, a local bath application of strychnine (a broad antagonist of glycine and GABAA receptors) to the spinal cord enhances thoracic inspiratory motor activity. Herein, to investigate the involvement of the inspiratory spinal interneurons that provide excitatory input to the motoneuron, we conducted calcium imaging using this preparation. Oregon Green 488 BAPTA-1 AM, a fluorescent calcium indicator, was injected into the ventromedial surface of the thoracic cord. In all cells that showed inspiratory-related fluorescence changes > 2% of the baseline fluorescence intensity, the inspiratory-related fluorescence change decreased when the focal depth was deepened. The application of strychnine to the spinal cord increased the inspiratory-related intracellular calcium rise in these cells. These results suggest that the enhancement of inspiratory interneuron activity could be involved in this enhancement of inspiratory motor activity.
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9
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Oku Y. Temporal variations in the pattern of breathing: techniques, sources, and applications to translational sciences. J Physiol Sci 2022; 72:22. [PMID: 36038825 DOI: 10.1186/s12576-022-00847-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 08/12/2022] [Indexed: 11/10/2022]
Abstract
The breathing process possesses a complex variability caused in part by the respiratory central pattern generator in the brainstem; however, it also arises from chemical and mechanical feedback control loops, network reorganization and network sharing with nonrespiratory motor acts, as well as inputs from cortical and subcortical systems. The notion that respiratory fluctuations contain hidden information has prompted scientists to decipher respiratory signals to better understand the fundamental mechanisms of respiratory pattern generation, interactions with emotion, influences on the cortical neuronal networks associated with cognition, and changes in variability in healthy and disease-carrying individuals. Respiration can be used to express and control emotion. Furthermore, respiration appears to organize brain-wide network oscillations via cross-frequency coupling, optimizing cognitive performance. With the aid of information theory-based techniques and machine learning, the hidden information can be translated into a form usable in clinical practice for diagnosis, emotion recognition, and mental conditioning.
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Affiliation(s)
- Yoshitaka Oku
- Division of Physiome, Department of Physiology, Hyogo Medical University, Nishinomiya, Hyogo, 663-8501, Japan.
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10
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Katsuki S, Ota S, Yoda S, Onimaru H, Dohi K, Izumizaki M. Effects of ANP and BNP on the generation of respiratory rhythms in brainstem-spinal cord preparation isolated from newborn rats. Biomed Res 2022; 43:127-135. [PMID: 35989288 DOI: 10.2220/biomedres.43.127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Natriuretic peptides (NPs) are a family of peptide hormones produced in cardiac muscle cells and consist mainly of three types: atrial NP (ANP), B-type (or brain) NP (BNP), and C-type NP. We herein report the effects of ANP and BNP on central respiratory activity in brainstem-spinal cord preparation isolated from newborn rats. Bath application of these peptides (100 nM) induced a weak transient depression of the respiratory rhythm followed by recovery. Respiratory-related neurons in the rostral ventrolateral medulla showed a tendency for transient hyperpolarization followed by recovery during the application of ANP or BNP. The application of a membrane-permeable cGMP, 8-Br-cGMP (10 or 20 μM), did not induce significant effects on respiratory rhythm, suggesting no involvement of guanylyl cyclase in effects of ANP or BNP. We also examined effects of BNP on respiratory depression induced by the sedative dexmedetomidine, which exerts an inhibitory influence on respiratory rhythm. When pretreated with 50 nM BNP, the inhibitory effect of 100 nM dexmedetomidine was significantly reduced. Our findings suggest that ANP and BNP act as mild excitatory agents with sustained effects on respiratory rhythm after an initial transient depression.
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Affiliation(s)
- Shino Katsuki
- Department of Physiology, Showa University School of Medicine.,Department of Emergency, Disaster and Critical Care Medicine, Showa University
| | - Shinichiro Ota
- Department of Physiology, Showa University School of Medicine
| | - Shunya Yoda
- Department of Physiology, Showa University School of Medicine
| | - Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine
| | - Kenji Dohi
- Department of Emergency, Disaster and Critical Care Medicine, Showa University
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11
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Barioni NO, Derakhshan F, Tenorio Lopes L, Onimaru H, Roy A, McDonald F, Scheibli E, Baghdadwala MI, Heidari N, Bharadia M, Ikeda K, Yazawa I, Okada Y, Harris MB, Dutschmann M, Wilson RJA. Novel oxygen sensing mechanism in the spinal cord involved in cardiorespiratory responses to hypoxia. Sci Adv 2022; 8:eabm1444. [PMID: 35333571 PMCID: PMC8956269 DOI: 10.1126/sciadv.abm1444] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 02/04/2022] [Indexed: 05/05/2023]
Abstract
As blood oxygenation decreases (hypoxemia), mammals mount cardiorespiratory responses, increasing oxygen to vital organs. The carotid bodies are the primary oxygen chemoreceptors for breathing, but sympathetic-mediated cardiovascular responses to hypoxia persist in their absence, suggesting additional high-fidelity oxygen sensors. We show that spinal thoracic sympathetic preganglionic neurons are excited by hypoxia and silenced by hyperoxia, independent of surrounding astrocytes. These spinal oxygen sensors (SOS) enhance sympatho-respiratory activity induced by CNS asphyxia-like stimuli, suggesting they bestow a life-or-death advantage. Our data suggest the SOS use a mechanism involving neuronal nitric oxide synthase 1 (NOS1) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX). We propose NOS1 serves as an oxygen-dependent sink for NADPH in hyperoxia. In hypoxia, NADPH catabolism by NOS1 decreases, increasing availability of NADPH to NOX and launching reactive oxygen species-dependent processes, including transient receptor potential channel activation. Equipped with this mechanism, SOS are likely broadly important for physiological regulation in chronic disease, spinal cord injury, and cardiorespiratory crisis.
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Affiliation(s)
- Nicole O. Barioni
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Fatemeh Derakhshan
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Luana Tenorio Lopes
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, Tokyo, Japan
| | - Arijit Roy
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Fiona McDonald
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Erika Scheibli
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Mufaddal I. Baghdadwala
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Negar Heidari
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Manisha Bharadia
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Keiko Ikeda
- Division of Internal Medicine, Murayama Medical Center, Musashimurayama, Tokyo, Japan
| | - Itaru Yazawa
- Global Research Center for Innovative Life Science, Peptide Drug Innovation, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo 142-8501, Japan
| | - Yasumasa Okada
- Division of Internal Medicine, Murayama Medical Center, Musashimurayama, Tokyo, Japan
| | - Michael B. Harris
- Department of Biological Sciences, California State University Long Beach, Long Beach, CA 90840, USA
| | - Mathias Dutschmann
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, 3052, Australia
| | - Richard J. A. Wilson
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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12
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Turk AZ, Bishop M, Adeck A, SheikhBahaei S. Astrocytic modulation of central pattern generating motor circuits. Glia 2022; 70:1506-1519. [PMID: 35212422 DOI: 10.1002/glia.24162] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 02/08/2022] [Accepted: 02/09/2022] [Indexed: 12/26/2022]
Abstract
Central pattern generators (CPGs) generate the rhythmic and coordinated neural features necessary for the proper conduction of complex behaviors. In particular, CPGs are crucial for complex motor behaviors such as locomotion, mastication, respiration, and vocal production. While the importance of these networks in modulating behavior is evident, the mechanisms driving these CPGs are still not fully understood. On the other hand, accumulating evidence suggests that astrocytes have a significant role in regulating the function of some of these CPGs. Here, we review the location, function, and role of astrocytes in locomotion, respiration, and mastication CPGs and propose that, similarly, astrocytes may also play a significant role in the vocalization CPG.
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Affiliation(s)
- Ariana Z Turk
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Mitchell Bishop
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Afuh Adeck
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Shahriar SheikhBahaei
- Neuron-Glia Signaling and Circuits Unit, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, Maryland, USA
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13
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Yazawa I, Okazaki S, Yokota S, Takeda K, Fukushi I, Yoshizawa M, Onimaru H, Okada Y. Coherence analysis of the calcium activity of putative astrocytic and neuronal cells on the L5 ventral horn and neural output in activated lumbar CPG networks. Neurosci Lett 2021; 771:136421. [PMID: 34968723 DOI: 10.1016/j.neulet.2021.136421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 12/03/2021] [Accepted: 12/22/2021] [Indexed: 11/18/2022]
Abstract
Astrocytes are thought to play a crucial role in providing structure to the spinal cord and maintaining efficient synaptic function and metabolism because their fine processes envelop the synapses of neurons and form many neuronal networks within the central nervous system (CNS). To investigate whether putative astrocytes and putative neurons distributed on the ventral horn play a role in the modulation of lumbar locomotor central pattern generator (CPG) networks, we used extracellular recording and optical imaging techniques and recorded the neural output from the left L5 ventral root and the calcium activity of putative astrocytes and neurons in the L5 ventral horn at the same time when activating an isolated L1-L5 spinal cord preparation from rats aged 0-2 days. Optical measurements detected cells that showed a fluorescence intensity change under all experimental conditions, namely, (1) 5-HT + NMDA, (2) TTX, and (3) TTX + Low K+. These cells were semiautomatically identified using an in-house MATLAB-based program, as putative astrocytes and neurons according to the cell classification, i.e., increased or decreased fluorescence intensity change (ΔF/F0), and subjective judgment based on their soma size. Coherence and its phase were calculated according to the calcium activity of the putative astrocytes and putative neurons, and neural output was calculated during fictive locomotion with in-house MATLAB-based programs. We found that the number of putative astrocytes activated by applying low K+ tends not to differ from that activated by applying the protease-activated receptor 1 (PAR1) selective agonist TFLLR-NH2 (TFLLR). Moreover, the calcium activity of several putative astrocytes and neurons synchronized with locomotor-like activity at a frequency range below 0.5 Hz and the time lag between peaks of cellular calcium activity and locomotor-like activity ranged from -1000 to + 1000 ms. These findings presumably indicates that these putative astrocytes and neurons in the left L5 ventral horn require -1000 to + 1000 ms to communicate with lumbar CPG networks and maintain efficient synaptic function and metabolism in activated lumbar CPG networks. This finding suggests the possibility that putative astrocytic and neuronal cells in the L5 ventral horn contribute to generating the rhythms and patterns of locomotor-like activity by activated CPG networks in the first to fifth lumbar spinal cord.
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Affiliation(s)
- Itaru Yazawa
- Global Research Center for Innovative Life Science, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Shinagawa, Tokyo 142-8501, Japan.
| | - Shuntaro Okazaki
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Tokyo 208-0011, Japan; Faculty of Human Sciences, Waseda University School of Human Sciences, Tokorozawa, Saitama 359-1192, Japan
| | - Shigefumi Yokota
- Department of Anatomy and Neurosciences, Shimane University School of Medicine, Izumo, Shimane 693-8501, Japan
| | - Kotaro Takeda
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Tokyo 208-0011, Japan; Faculty of Rehabilitation, Fujita Health University School of Healthcare, Toyoake, Aichi 470-1192, Japan
| | - Isato Fukushi
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Tokyo 208-0011, Japan; Faculty of Health Sciences, Uekusa Gakuen University, Chiba, Chiba 264-0007, Japan
| | - Masashi Yoshizawa
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Tokyo 208-0011, Japan; Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi 409-3898, Japan
| | - Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, Shinagawa, Tokyo 142-8555, Japan
| | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Tokyo 208-0011, Japan
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14
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Fukushi I, Takeda K, Pokorski M, Kono Y, Yoshizawa M, Hasebe Y, Nakao A, Mori Y, Onimaru H, Okada Y. Activation of Astrocytes in the Persistence of Post-hypoxic Respiratory Augmentation. Front Physiol 2021; 12:757731. [PMID: 34690820 PMCID: PMC8531090 DOI: 10.3389/fphys.2021.757731] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/15/2021] [Indexed: 11/16/2022] Open
Abstract
Acute hypoxia increases ventilation. After cessation of hypoxia loading, ventilation decreases but remains above the pre-exposure baseline level for a time. However, the mechanism of this post-hypoxic persistent respiratory augmentation (PHRA), which is a short-term potentiation of breathing, has not been elucidated. We aimed to test the hypothesis that astrocytes are involved in PHRA. To this end, we investigated hypoxic ventilatory responses by whole-body plethysmography in unanesthetized adult mice. The animals breathed room air, hypoxic gas mixture (7% O2, 93% N2) for 2min, and again room air for 10min before and after i.p. administration of low (100mg/kg) and high (300mg/kg) doses of arundic acid (AA), an astrocyte inhibitor. AA suppressed PHRA, with the high dose decreasing ventilation below the pre-hypoxic level. Further, we investigated the role of the astrocytic TRPA1 channel, a putative ventilatory hypoxia sensor, in PHRA using astrocyte-specific Trpa1 knockout (asTrpa1−/−) and floxed Trpa1 (Trpa1f/f) mice. In both Trpa1f/f and asTrpa1−/− mice, PHRA was noticeable, indicating that the astrocyte TRPA1 channel was not directly involved in PHRA. Taken together, these results indicate that astrocytes mediate the PHRA by mechanisms other than TRPA1 channels that are engaged in hypoxia sensing.
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Affiliation(s)
- Isato Fukushi
- Faculty of Health Sciences, Uekusa Gakuen University, Chiba, Japan.,Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
| | - Kotaro Takeda
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Faculty of Rehabilitation, School of Healthcare, Fujita Health University, Toyoake, Japan
| | - Mieczyslaw Pokorski
- Institute of Health Sciences, University of Opole, Opole, Poland.,Faculty of Health Sciences, The Jan Dlugosz University in Czestochowa, Czestochowa, Poland
| | - Yosuke Kono
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Masashi Yoshizawa
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Yohei Hasebe
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Akito Nakao
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Yasuo Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, Tokyo, Japan
| | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
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15
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Mutolo D, Bongianni F, Pantaleo T, Cinelli E. The lamprey respiratory network: Some evolutionary aspects. Respir Physiol Neurobiol 2021; 294:103766. [PMID: 34329767 DOI: 10.1016/j.resp.2021.103766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/19/2021] [Accepted: 07/25/2021] [Indexed: 01/25/2023]
Abstract
Breathing is a complex behaviour that involves rhythm generating networks. In this review, we examine the main characteristics of respiratory rhythm generation in vertebrates and, in particular, we describe the main results of our studies on the role of neural mechanisms involved in the neuromodulation of the lamprey respiration. The lamprey respiratory rhythm generator is located in the paratrigeminal respiratory group (pTRG) and shows similarities with the mammalian preBötzinger complex. In fact, within the pTRG a major role is played by glutamate, but also GABA and glycine display important contributions. In addition, neuromodulatory influences are exerted by opioids, substance P, acetylcholine and serotonin. Both structures respond to exogenous ATP with a biphasic response and astrocytes there located strongly contribute to the modulation of the respiratory pattern. The results emphasize that some important characteristics of the respiratory rhythm generating network are, to a great extent, maintained throughout evolution.
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16
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Abstract
Astrocytes are a functionally diverse form of glial cell involved in various aspects of nervous system infrastructure, from the metabolic and structural support of neurons to direct neuromodulation of synaptic activity. Investigating how astrocytes behave in functionally related circuits may help us understand whether there is any conserved logic to the role of astrocytes within neuronal networks. Astrocytes are implicated as key neuromodulatory cells within neural circuits that control a number of rhythmic behaviours such as breathing, locomotion and circadian sleep-wake cycles. In this review, we examine the evidence that astrocytes are directly involved in the regulation of the neural circuits underlying six different rhythmic behaviours: locomotion, breathing, chewing, gastrointestinal motility, circadian sleep-wake cycles and oscillatory feeding behaviour. We discuss how astrocytes are integrated into the neuronal networks that regulate these behaviours, and identify the potential gliotransmission signalling mechanisms involved. From reviewing the evidence of astrocytic involvement in a range of rhythmic behaviours, we reveal a heterogenous array of gliotransmission mechanisms, which help to regulate neuronal networks. However, we also observe an intriguing thread of commonality, in the form of purinergic gliotransmission, which is frequently utilised to facilitate feedback inhibition within rhythmic networks to constrain a given behaviour within its operational range.
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Affiliation(s)
- Matthew J Broadhead
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK.
| | - Gareth B Miles
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, UK
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17
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Onimaru H, Yazawa I, Takeda K, Fukushi I, Okada Y. Calcium Imaging Analysis of Cellular Responses to Hypercapnia and Hypoxia in the NTS of Newborn Rat Brainstem Preparation. Front Physiol 2021; 12:645904. [PMID: 33841182 PMCID: PMC8027497 DOI: 10.3389/fphys.2021.645904] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 03/08/2021] [Indexed: 01/13/2023] Open
Abstract
It is supposed that the nucleus of the solitary tract (NTS) in the dorsal medulla includes gas sensor cells responsive to hypercapnia or hypoxia in the central nervous system. In the present study, we analyzed cellular responses to hypercapnia and hypoxia in the NTS region of newborn rat in vitro preparation. The brainstem and spinal cord were isolated from newborn rat (P0-P4) and were transversely cut at the level of the rostral area postrema. To detect cellular responses, calcium indicator Oregon Green was pressure-injected into the NTS just beneath the cut surface of either the caudal or rostral block of the medulla, and the preparation was superfused with artificial cerebrospinal fluid (25–26°C). We examined cellular responses initially to hypercapnic stimulation (to 8% CO2 from 2% CO2) and then to hypoxic stimulation (to 0% O2 from 95% O2 at 5% CO2). We tested these responses in standard solution and in two different synapse blockade solutions: (1) cocktail blockers solution including bicuculline, strychnine, NBQX and MK-801 or (2) TTX solution. At the end of the experiments, the superfusate potassium concentration was lowered to 0.2 from 3 mM to classify recorded cells into neurons and astrocytes. Excitation of cells was detected as changes of fluorescence intensity with a confocal calcium imaging system. In the synaptic blockade solutions (cocktail or TTX solution), 7.6 and 8% of the NTS cells responded to hypercapnic and hypoxic stimulation, respectively, and approximately 2% of them responded to both stimulations. Some of these cells responded to low K+, and they were classified into astrocytes comprising 43% hypercapnia-sensitive cells, 56% hypoxia-sensitive cells and 54% of both stimulation-sensitive cells. Of note, 49% of the putative astrocytes identified by low K+ stimulation were sensitive to hypercapnia, hypoxia or both. In the presence of a glia preferential blocker, 5 mM fluoroacetate (plus 0.5 μM TTX), the percentage of hypoxia-sensitive cells was significantly reduced compared to those of all other conditions. This is the first study to reveal that the NTS includes hypercapnia and hypoxia dual-sensitive cells. These results suggest that astrocytes in the NTS region could act as a central gas sensor.
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Affiliation(s)
- Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, Tokyo, Japan
| | - Itaru Yazawa
- Global Research Center for Innovative Life Science, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan
| | - Kotaro Takeda
- Faculty of Rehabilitation, School of Healthcare, Fujita Health University, Toyoake, Japan
| | - Isato Fukushi
- Faculty of Health Sciences, Uekusa Gakuen University, Chiba, Japan.,Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
| | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
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18
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Hwang SN, Lee JS, Seo K, Lee H. Astrocytic Regulation of Neural Circuits Underlying Behaviors. Cells 2021; 10:cells10020296. [PMID: 33535587 PMCID: PMC7912785 DOI: 10.3390/cells10020296] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/23/2021] [Accepted: 01/29/2021] [Indexed: 02/07/2023] Open
Abstract
Astrocytes, characterized by a satellite-like morphology, are the most abundant type of glia in the central nervous system. Their main functions have been thought to be limited to providing homeostatic support for neurons, but recent studies have revealed that astrocytes actually actively interact with local neural circuits and play a crucial role in information processing and generating physiological and behavioral responses. Here, we review the emerging roles of astrocytes in many brain regions, particularly by focusing on intracellular changes in astrocytes and their interactions with neurons at the molecular and neural circuit levels.
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Affiliation(s)
- Sun-Nyoung Hwang
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea;
| | - Jae Seung Lee
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea; (J.S.L.); (K.S.)
| | - Kain Seo
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea; (J.S.L.); (K.S.)
| | - Hyosang Lee
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea;
- Department of Brain and Cognitive Sciences, DGIST, Daegu 42988, Korea; (J.S.L.); (K.S.)
- Korea Brain Research Institute (KBRI), Daegu 41062, Korea
- Correspondence: ; Tel.: +82-53-785-6147
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19
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Abstract
Animal behavior was classically considered to be determined exclusively by neuronal activity, whereas surrounding glial cells such as astrocytes played only supportive roles. However, astrocytes are as numerous as neurons in the mammalian brain, and current findings indicate a chemically based dialog between astrocytes and neurons. Activation of astrocytes by synaptically released neurotransmitters converges on regulating intracellular Ca2+ in astrocytes, which then can regulate the efficacy of near and distant tripartite synapses at diverse timescales through gliotransmitter release. Here, we discuss recent evidence on how diverse behaviors are impacted by this dialog. These recent findings support a paradigm shift in neuroscience, in which animal behavior does not result exclusively from neuronal activity but from the coordinated activity of both astrocytes and neurons. Decoding how astrocytes and neurons interact with each other in various brain circuits will be fundamental to fully understanding how behaviors originate and become dysregulated in disease.
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Affiliation(s)
- Paulo Kofuji
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA;
| | - Alfonso Araque
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA;
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20
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Broadhead MJ, Miles GB. Bi-Directional Communication Between Neurons and Astrocytes Modulates Spinal Motor Circuits. Front Cell Neurosci 2020; 14:30. [PMID: 32180706 PMCID: PMC7057799 DOI: 10.3389/fncel.2020.00030] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 02/03/2020] [Indexed: 01/22/2023] Open
Abstract
Evidence suggests that astrocytes are not merely supportive cells in the nervous system but may actively participate in the control of neural circuits underlying cognition and behavior. In this study, we examined the role of astrocytes within the motor circuitry of the mammalian spinal cord. Pharmacogenetic manipulation of astrocytic activity in isolated spinal cord preparations obtained from neonatal mice revealed astrocyte-derived, adenosinergic modulation of the frequency of rhythmic output generated by the locomotor central pattern generator (CPG) network. Live Ca2+ imaging demonstrated increased activity in astrocytes during locomotor-related output and in response to the direct stimulation of spinal neurons. Finally, astrocytes were found to respond to neuronally-derived glutamate in a metabotropic glutamate receptor 5 (mGluR5) dependent manner, which in turn drives astrocytic modulation of the locomotor network. Our work identifies bi-directional signaling mechanisms between neurons and astrocytes underlying modulatory feedback control of motor circuits, which may act to constrain network output within optimal ranges for movement.
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Affiliation(s)
- Matthew J Broadhead
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, United Kingdom
| | - Gareth B Miles
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, United Kingdom
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21
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Juneja DS, Nasuto S, Delivopoulos E. Fast and Efficient Differentiation of Mouse Embryonic Stem Cells Into ATP-Responsive Astrocytes. Front Cell Neurosci 2020; 13:579. [PMID: 32038173 PMCID: PMC6985097 DOI: 10.3389/fncel.2019.00579] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/16/2019] [Indexed: 12/25/2022] Open
Abstract
Astrocytes are multifunctional cells in the CNS, involved in the regulation of neurovascular coupling, the modulation of electrolytes, and the cycling of neurotransmitters at synapses. Induction of astrocytes from stem cells remains a largely underdeveloped area, as current protocols are time consuming, lack granularity in astrocytic subtype generation, and often are not as efficient as neural induction methods. In this paper we present an efficient method to differentiate astrocytes from mouse embryonic stem cells. Our technique uses a cell suspension protocol to produce embryoid bodies (EBs) that are neurally inducted and seeded onto laminin coated surfaces. Plated EBs attach to the surface and release migrating cells to their surrounding environment, which are further inducted into the astrocytic lineage, through an optimized, heparin-based media. Characterization and functional assessment of the cells consists of immunofluorescent labeling for specific astrocytic proteins and sensitivity to adenosine triphosphate (ATP) stimulation. Our experimental results show that even at the earliest stages of the protocol, cells are positive for astrocytic markers (GFAP, ALDH1L1, S100β, and GLAST) with variant expression patterns and purinergic receptors (P2Y). Generated astrocytes also exhibit differential Ca2+ transients upon stimulation with ATP, which evolve over the differentiation period. Metabotropic purinoceptors P2Y1R are expressed and we offer preliminary evidence that metabotropic purinoceptors contribute to Ca2+ transients. Our protocol is simple, efficient and fast, facilitating its use in multiple investigations, particularly in vitro studies of engineered neural networks.
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22
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Hirbec H, Déglon N, Foo LC, Goshen I, Grutzendler J, Hangen E, Kreisel T, Linck N, Muffat J, Regio S, Rion S, Escartin C. Emerging technologies to study glial cells. Glia 2020; 68:1692-1728. [PMID: 31958188 DOI: 10.1002/glia.23780] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 12/11/2022]
Abstract
Development, physiological functions, and pathologies of the brain depend on tight interactions between neurons and different types of glial cells, such as astrocytes, microglia, oligodendrocytes, and oligodendrocyte precursor cells. Assessing the relative contribution of different glial cell types is required for the full understanding of brain function and dysfunction. Over the recent years, several technological breakthroughs were achieved, allowing "glio-scientists" to address new challenging biological questions. These technical developments make it possible to study the roles of specific cell types with medium or high-content workflows and perform fine analysis of their mutual interactions in a preserved environment. This review illustrates the potency of several cutting-edge experimental approaches (advanced cell cultures, induced pluripotent stem cell (iPSC)-derived human glial cells, viral vectors, in situ glia imaging, opto- and chemogenetic approaches, and high-content molecular analysis) to unravel the role of glial cells in specific brain functions or diseases. It also illustrates the translation of some techniques to the clinics, to monitor glial cells in patients, through specific brain imaging methods. The advantages, pitfalls, and future developments are discussed for each technique, and selected examples are provided to illustrate how specific "gliobiological" questions can now be tackled.
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Affiliation(s)
- Hélène Hirbec
- Institute for Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Nicole Déglon
- Laboratory of Neurotherapies and Neuromodulation, Department of Clinical Neuroscience, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland.,Laboratory of Neurotherapies and Neuromodulation, Neuroscience Research Center, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Lynette C Foo
- Neuroimmunology and Neurodegeneration Section, The Neuroscience and Rare Diseases Discovery and Translational Area, F. Hoffman-La Roche, Basel, Switzerland
| | - Inbal Goshen
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Jaime Grutzendler
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Emilie Hangen
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département de la Recherche Fondamentale, Institut de Biologie François Jacob, MIRCen, Fontenay-aux-Roses, France.,Centre National de la Recherche Scientifique, Neurodegenerative Diseases Laboratory, Université Paris-Sud, Université Paris-Saclay, UMR 9199, Fontenay-aux-Roses, France
| | - Tirzah Kreisel
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nathalie Linck
- Institute for Functional Genomics (IGF), University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Julien Muffat
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, and Department of Molecular Genetics, The University of Toronto, Toronto, Canada
| | - Sara Regio
- Laboratory of Neurotherapies and Neuromodulation, Department of Clinical Neuroscience, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland.,Laboratory of Neurotherapies and Neuromodulation, Neuroscience Research Center, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Sybille Rion
- Neuroimmunology and Neurodegeneration Section, The Neuroscience and Rare Diseases Discovery and Translational Area, F. Hoffman-La Roche, Basel, Switzerland
| | - Carole Escartin
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département de la Recherche Fondamentale, Institut de Biologie François Jacob, MIRCen, Fontenay-aux-Roses, France.,Centre National de la Recherche Scientifique, Neurodegenerative Diseases Laboratory, Université Paris-Sud, Université Paris-Saclay, UMR 9199, Fontenay-aux-Roses, France
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23
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Patodia S, Paradiso B, Ellis M, Somani A, Sisodiya SM, Devinsky O, Thom M. Characterisation of medullary astrocytic populations in respiratory nuclei and alterations in sudden unexpected death in epilepsy. Epilepsy Res 2019; 157:106213. [PMID: 31610338 DOI: 10.1016/j.eplepsyres.2019.106213] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/20/2019] [Accepted: 09/30/2019] [Indexed: 12/29/2022]
Abstract
Central failure of respiration during a seizure is one possible mechanism for sudden unexpected death in epilepsy (SUDEP). Neuroimaging studies indicate volume loss in the medulla in SUDEP and a post mortem study has shown reduction in neuromodulatory neuropeptidergic and monoaminergic neurones in medullary respiratory nuclear groups. Specialised glial cells identified in the medulla are considered essential for normal respiratory regulation including astrocytes with pacemaker properties in the pre-Botzinger complex and populations of subpial and perivascular astrocytes, sensitive to increased pCO2, that excite respiratory neurones. Our aim was to explore niches of medullary astrocytes in SUDEP cases compared to controls. In 48 brainstems from three groups, SUDEP (20), epilepsy controls (10) and non-epilepsy controls (18), sections through the medulla were labelled for GFAP, vimentin and functional markers, astrocytic gap junction protein connexin43 (Cx43) and adenosine A1 receptor (A1R). Regions including the ventro-lateral medulla (VLM; for the pre-Bötzinger complex), Median Raphe (MR) and lateral medullary subpial layer (MSPL) were quantified using image analysis for glial cell populations and compared between groups. Findings included morphologically and regionally distinct vimentin/Cx34-positive glial cells in the VLM and MR in close proximity to neurones. We noted a reduction of vimentin-positive glia in the VLM and MSPL and Cx43 glia in the MR in SUDEP cases compared to control groups (p < 0.05-0.005). In addition, we identified vimentin, Cx43 and A1R positive glial cells in the MSPL region which likely correspond to chemosensory glia identified experimentally. In conclusion, altered medullary glial cell populations could contribute to impaired respiratory regulatory capacity and vulnerability to SUDEP and warrant further investigation.
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Affiliation(s)
- Smriti Patodia
- Departments of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, United Kingdom
| | - Beatrice Paradiso
- Departments of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, United Kingdom; Cardiovascular Pathology Unit, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua Medical School, Padua, Italy
| | - Matthew Ellis
- Departments of Neuropathology, UCL Queen Square Institute of Neurology, London, WC1N 3BG, United Kingdom
| | - Alyma Somani
- Departments of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, United Kingdom
| | - Sanjay M Sisodiya
- Departments of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, United Kingdom
| | - Orrin Devinsky
- New York University School of Medicine, Comprehensive Epilepsy Center, New York, United States
| | - Maria Thom
- Departments of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, United Kingdom; Departments of Neuropathology, UCL Queen Square Institute of Neurology, London, WC1N 3BG, United Kingdom.
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24
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Abstract
Breathing is a well-described, vital and surprisingly complex behaviour, with behavioural and physiological outputs that are easy to directly measure. Key neural elements for generating breathing pattern are distinct, compact and form a network amenable to detailed interrogation, promising the imminent discovery of molecular, cellular, synaptic and network mechanisms that give rise to the behaviour. Coupled oscillatory microcircuits make up the rhythmic core of the breathing network. Primary among these is the preBötzinger Complex (preBötC), which is composed of excitatory rhythmogenic interneurons and excitatory and inhibitory pattern-forming interneurons that together produce the essential periodic drive for inspiration. The preBötC coordinates all phases of the breathing cycle, coordinates breathing with orofacial behaviours and strongly influences, and is influenced by, emotion and cognition. Here, we review progress towards cracking the inner workings of this vital core.
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25
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Forsberg D, Herlenius E. Astrocyte networks modulate respiration – sniffing glue. Respir Physiol Neurobiol 2019; 265:3-8. [DOI: 10.1016/j.resp.2018.06.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 06/17/2018] [Accepted: 06/29/2018] [Indexed: 12/11/2022]
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26
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Cui Y, Yang Y, Dong Y, Hu H. Decoding Depression: Insights from Glial and Ketamine Regulation of Neuronal Burst Firing in Lateral Habenula. Cold Spring Harb Symp Quant Biol 2019; 83:141-150. [PMID: 30718267 DOI: 10.1101/sqb.2018.83.036871] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The rapid antidepressant effect of ketamine is arguably one of the most significant advances in the mental health field in the last half century. However, its mechanism of action has remained elusive. Here, we describe our latest discovery on how ketamine blocks N-methyl-D-aspartate receptor (NMDAR)-dependent burst firing of an "antireward" center in the brain, the lateral habenula (LHb), to mediate its antidepressant effects. We also discuss a novel structure-function mechanism at the glia-neuron interface to account for the enhanced LHb bursting during depression. These results reveal new molecular targets for the therapeutic intervention of major depression.
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Affiliation(s)
- Yihui Cui
- Center for Neuroscience and Department of Psychiatry of First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou 310058, China
| | - Yan Yang
- Center for Neuroscience and Department of Psychiatry of First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou 310058, China
| | - Yiyan Dong
- Center for Neuroscience and Department of Psychiatry of First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou 310058, China.,Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou 310058, China
| | - Hailan Hu
- Center for Neuroscience and Department of Psychiatry of First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou 310058, China.,Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou 310058, China.,Mental Health Center, Zhejiang University, Hangzhou 310013, China
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27
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Shinozaki Y, Yokota S, Miwakeichi F, Pokorski M, Aoyama R, Fukuda K, Yoshida H, Toyama Y, Nakamura M, Okada Y. Structural and functional identification of two distinct inspiratory neuronal populations at the level of the phrenic nucleus in the rat cervical spinal cord. Brain Struct Funct 2019; 224:57-72. [PMID: 30251026 DOI: 10.1007/s00429-018-1757-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/18/2018] [Indexed: 11/22/2022]
Abstract
The diaphragm is driven by phrenic motoneurons that are located in the cervical spinal cord. Although the anatomical location of the phrenic nucleus and the function of phrenic motoneurons at a single cellular level have been extensively analyzed, the spatiotemporal dynamics of phrenic motoneuron group activity have not been fully elucidated. In the present study, we analyzed the functional and structural characteristics of respiratory neuron population in the cervical spinal cord at the level of the phrenic nucleus by voltage imaging, together with histological analysis of neuronal and astrocytic distribution in the cervical spinal cord. We found spatially distinct two cellular populations that exhibited synchronized inspiratory activity on the transversely cut plane at C4–C5 levels and on the ventral surface of the mid cervical spinal cord in the isolated brainstem–spinal cord preparation of the neonatal rat. Inspiratory activity of one group emerged in the central portion of the ventral horn that corresponded to the central motor column, and the other appeared in the medial portion of the ventral horn that corresponded to the medial motor column. We identified by retrogradely labeling study that the anatomical distributions of phrenic and scalene motoneurons coincided with optically detected central and medial motor regions, respectively. Furthermore, we anatomically demonstrated closely located features of putative motoneurons, interneurons and astrocytes in these regions. Collectively, we report that phrenic and scalene motoneuron populations show synchronized inspiratory activities with distinct anatomical locations in the mid cervical spinal cord.
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28
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SheikhBahaei S, Morris B, Collina J, Anjum S, Znati S, Gamarra J, Zhang R, Gourine AV, Smith JC. Morphometric analysis of astrocytes in brainstem respiratory regions. J Comp Neurol 2018; 526:2032-2047. [PMID: 29888789 PMCID: PMC6158060 DOI: 10.1002/cne.24472] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 05/07/2018] [Accepted: 05/13/2018] [Indexed: 12/30/2022]
Abstract
Astrocytes, the most abundant and structurally complex glial cells of the central nervous system, are proposed to play an important role in modulating the activities of neuronal networks, including respiratory rhythm‐generating circuits of the preBötzinger complex (preBötC) located in the ventrolateral medulla of the brainstem. However, structural properties of astrocytes residing within different brainstem regions are unknown. In this study astrocytes in the preBötC, an intermediate reticular formation (IRF) region with respiratory‐related function, and a region of the nucleus tractus solitarius (NTS) in adult rats were reconstructed and their morphological features were compared. Detailed morphological analysis revealed that preBötC astrocytes are structurally more complex than those residing within the functionally distinct neighboring IRF region, or the NTS, located at the dorsal aspect of the medulla oblongata. Structural analyses of the brainstem microvasculature indicated no significant regional differences in vascular properties. We hypothesize that high morphological complexity of preBötC astrocytes reflects their functional role in providing structural/metabolic support and modulation of the key neuronal circuits essential for breathing, as well as constraints imposed by arrangements of associated neurons and/or other local structural features of the brainstem parenchyma.
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Affiliation(s)
- Shahriar SheikhBahaei
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland.,Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London, UK
| | - Brian Morris
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Jared Collina
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Sommer Anjum
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Sami Znati
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Julio Gamarra
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Ruli Zhang
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London, UK
| | - Jeffrey C Smith
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
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29
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Ramirez JM, Severs LJ, Ramirez SC, Agosto‐Marlin IM. Advances in cellular and integrative control of oxygen homeostasis within the central nervous system. J Physiol 2018; 596:3043-3065. [PMID: 29742297 PMCID: PMC6068258 DOI: 10.1113/jp275890] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 04/04/2018] [Indexed: 12/31/2022] Open
Abstract
Mammals must continuously regulate the levels of O2 and CO2 , which is particularly important for the brain. Failure to maintain adequate O2 /CO2 homeostasis has been associated with numerous disorders including sleep apnoea, Rett syndrome and sudden infant death syndrome. But, O2 /CO2 homeostasis poses major regulatory challenges, even in the healthy brain. Neuronal activities change in a differentiated, spatially and temporally complex manner, which is reflected in equally complex changes in O2 demand. This raises important questions: is oxygen sensing an emergent property, locally generated within all active neuronal networks, and/or the property of specialized O2 -sensitive CNS regions? Increasing evidence suggests that the regulation of the brain's redox state involves properties that are intrinsic to many networks, but that specialized regions in the brainstem orchestrate the integrated control of respiratory and cardiovascular functions. Although the levels of O2 in arterial blood and the CNS are very different, neuro-glial interactions and purinergic signalling are critical for both peripheral and CNS chemosensation. Indeed, the specificity of neuroglial interactions seems to determine the differential responses to O2 , CO2 and the changes in pH.
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Affiliation(s)
- Jan Marino Ramirez
- Center for Integrative Brain ResearchSeattle Children's Research InstituteDepartment of Neurological SurgeryUniversity of Washington School of MedicineSeattleWAUSA
- Department of Physiology and BiophysicsUniversity of WashingtonSeattleWAUSA
| | - Liza J. Severs
- Department of Physiology and BiophysicsUniversity of WashingtonSeattleWAUSA
| | - Sanja C. Ramirez
- Center for Integrative Brain ResearchSeattle Children's Research InstituteDepartment of Neurological SurgeryUniversity of Washington School of MedicineSeattleWAUSA
| | - Ibis M. Agosto‐Marlin
- Center for Integrative Brain ResearchSeattle Children's Research InstituteDepartment of Neurological SurgeryUniversity of Washington School of MedicineSeattleWAUSA
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30
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Kottick A, Martin CA, Del Negro CA. Fate mapping neurons and glia derived from Dbx1-expressing progenitors in mouse preBötzinger complex. Physiol Rep 2018; 5:5/11/e13300. [PMID: 28611151 PMCID: PMC5471439 DOI: 10.14814/phy2.13300] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 04/27/2017] [Accepted: 05/01/2017] [Indexed: 01/23/2023] Open
Abstract
The brainstem preBötzinger complex (preBötC) generates the inspiratory breathing rhythm, and its core rhythmogenic interneurons are derived from Dbx1‐expressing progenitors. To study the neural bases of breathing, tamoxifen‐inducible Cre‐driver mice and Cre‐dependent reporters are used to identify, record, and perturb Dbx1 preBötC neurons. However, the relationship between tamoxifen administration and reporter protein expression in preBötC neurons and glia has not been quantified. To address this problem, we crossed mice that express tamoxifen‐inducible Cre recombinase under the control of the Dbx1 gene (Dbx1CreERT2) with Cre‐dependent fluorescent reporter mice (Rosa26tdTomato), administered tamoxifen at different times during development, and analyzed tdTomato expression in the preBötC of their offspring. We also crossed Rosa26tdTomato reporters with mice that constitutively express Cre driven by Dbx1 (Dbx1Cre) and analyzed tdTomato expression in the preBötC of their offspring for comparison. We show that Dbx1‐expressing progenitors give rise to preBötC neurons and glia. Peak neuronal tdTomato expression occurs when tamoxifen is administered at embryonic day 9.5 (E9.5), whereas tdTomato expression in glia shows no clear relationship with tamoxifen timing. These results can be used to bias reporter protein expression in neurons (or glia). Tamoxifen administration at E9.5 labels 91% of Dbx1‐derived neurons in the preBötC, yet only 48% of Dbx1‐derived glia. By fate mapping Dbx1‐expressing progenitors, this study illustrates the developmental assemblage of Dbx1‐derived cells in preBötC, which can be used to design intersectional Cre/lox experiments that interrogate its cellular composition, structure, and function.
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Affiliation(s)
- Andrew Kottick
- Department of Applied Science, The College of William and Mary, Williamsburg, Virginia
| | - Caroline A Martin
- Department of Applied Science, The College of William and Mary, Williamsburg, Virginia
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31
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Abstract
Neural networks, including the respiratory network, can undergo a reconfiguration process by just changing the number, the connectivity or the activity of their elements. Those elements can be either brain regions or neurons, which constitute the building blocks of macrocircuits and microcircuits, respectively. The reconfiguration processes can also involve changes in the number of connections and/or the strength between the elements of the network. These changes allow neural networks to acquire different topologies to perform a variety of functions or change their responses as a consequence of physiological or pathological conditions. Thus, neural networks are not hardwired entities, but they constitute flexible circuits that can be constantly reconfigured in response to a variety of stimuli. Here, we are going to review several examples of these processes with special emphasis on the reconfiguration of the respiratory rhythm generator in response to different patterns of hypoxia, which can lead to changes in respiratory patterns or lasting changes in frequency and/or amplitude.
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Affiliation(s)
- Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, UNAM-Campus Juriquilla, Boulevard Juriquilla 3001, Querétaro, 76230, Mexico.
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32
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Onimaru H, Nakamura S, Ikeda K, Kawakami K, Inoue T. Confocal calcium imaging analysis of respiratory-related burst activity in the parafacial region. Brain Res Bull 2018; 139:16-20. [PMID: 29374604 DOI: 10.1016/j.brainresbull.2018.01.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 01/18/2018] [Indexed: 11/25/2022]
Abstract
The parafacial respiratory group (pFRG) surrounding the ventrolateral part of the facial motor nucleus is one of respiratory rhythm generators that consists of pre-inspiratory (Pre-I) neurons. Previous studies showed that most of the Pre-I neurons locating in the Phox2b cluster of the rostral ventral medulla were also Phox2b positive and intrinsically CO2 sensitive. However, it is not clear what percentage of Phox2b-expressing cells in the pFRG of the ventral medulla are Pre-I neurons. To address this issue, we analyzed the activity of Phox2b-positive cells by calcium imaging using a confocal laser microscope in transgenic rats in which Phox2b-positive cells expressed EYFP. We found that more than 60% of the EYFP/Phox2b-positive cells showed Pre-I neuron-like rhythmic burst activity in the parafacial region of newborn rat.
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Affiliation(s)
- Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
| | - Shiro Nakamura
- Department of Oral Physiology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Keiko Ikeda
- Department of Physiology, International University of Health and Welfare (IUHW), 4-3 Kozunomori, Narita City, Chiba 286-8686, Japan
| | - Kiyoshi Kawakami
- Division of Biology, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Tochigi 329-0498, Japan
| | - Tomio Inoue
- Department of Oral Physiology, Showa University School of Dentistry, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
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33
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Sheikhbahaei S, Turovsky EA, Hosford PS, Hadjihambi A, Theparambil SM, Liu B, Marina N, Teschemacher AG, Kasparov S, Smith JC, Gourine AV. Astrocytes modulate brainstem respiratory rhythm-generating circuits and determine exercise capacity. Nat Commun 2018; 9:370. [PMID: 29371650 DOI: 10.1038/s41467-017-02723-6] [Citation(s) in RCA: 94] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 12/19/2017] [Indexed: 11/29/2022] Open
Abstract
Astrocytes are implicated in modulation of neuronal excitability and synaptic function, but it remains unknown if these glial cells can directly control activities of motor circuits to influence complex behaviors in vivo. This study focused on the vital respiratory rhythm-generating circuits of the preBötzinger complex (preBötC) and determined how compromised function of local astrocytes affects breathing in conscious experimental animals (rats). Vesicular release mechanisms in astrocytes were disrupted by virally driven expression of either the dominant-negative SNARE protein or light chain of tetanus toxin. We show that blockade of vesicular release in preBötC astrocytes reduces the resting breathing rate and frequency of periodic sighs, decreases rhythm variability, impairs respiratory responses to hypoxia and hypercapnia, and dramatically reduces the exercise capacity. These findings indicate that astrocytes modulate the activity of CNS circuits generating the respiratory rhythm, critically contribute to adaptive respiratory responses in conditions of increased metabolic demand and determine the exercise capacity. Circuits of the preBötzinger complex generate rhythms needed for breathing. Here, the authors provide evidence, using a combination of chemogenetic approaches and approaches to inhibit vesicular release, that astrocytes play a role in regulating respiratory rate.
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34
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Forsberg D, Ringstedt T, Herlenius E. Astrocytes release prostaglandin E2 to modify respiratory network activity. eLife 2017; 6:29566. [PMID: 28976306 PMCID: PMC5648524 DOI: 10.7554/elife.29566] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 10/03/2017] [Indexed: 12/31/2022] Open
Abstract
Previously (Forsberg et al., 2016), we revealed that prostaglandin E2 (PGE2), released during hypercapnic challenge, increases calcium oscillations in the chemosensitive parafacial respiratory group (pFRG/RTN). Here, we demonstrate that pFRG/RTN astrocytes are the PGE2 source. Two distinct astrocyte subtypes were found using transgenic mice expressing GFP and MrgA1 receptors in astrocytes. Although most astrocytes appeared dormant during time-lapse calcium imaging, a subgroup displayed persistent, rhythmic oscillating calcium activity. These active astrocytes formed a subnetwork within the respiratory network distinct from the neuronal network. Activation of exogenous MrgA1Rs expressed in astrocytes tripled astrocytic calcium oscillation frequency in both the preBötzinger complex and pFRG/RTN. However, neurons in the preBötC were unaffected, whereas neuronal calcium oscillatory frequency in pFRG/RTN doubled. Notably, astrocyte activation in pFRG/RTN triggered local PGE2 release and blunted the hypercapnic response. Thus, astrocytes play an active role in respiratory rhythm modulation, modifying respiratory-related behavior through PGE2 release in the pFRG/RTN.
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Affiliation(s)
- David Forsberg
- Department of Women's and Children's Health, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Thomas Ringstedt
- Department of Women's and Children's Health, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Eric Herlenius
- Department of Women's and Children's Health, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
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35
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Abstract
Astrocytes are proposed to converse with neurons at tripartite synapses, detecting neurotransmitter release and responding with release of gliotransmitters, which in turn modulate synaptic strength and neuronal excitability. However, a paucity of evidence from behavioral studies calls into question the importance of gliotransmission for the operation of the nervous system in healthy animals. Central pattern generator (CPG) networks in the spinal cord and brain stem coordinate the activation of muscles during stereotyped activities such as locomotion, inspiration, and mastication and may therefore provide tractable models in which to assess the contribution of gliotransmission to behaviorally relevant neural activity. We review evidence for gliotransmission within spinal locomotor networks, including studies indicating that adenosine derived from astrocytes regulates the speed of locomotor activity via metamodulation of dopamine signaling.
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Affiliation(s)
- David Acton
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife , United Kingdom
| | - Gareth B Miles
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife , United Kingdom
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36
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Mutolo D. Brainstem mechanisms underlying the cough reflex and its regulation. Respir Physiol Neurobiol 2017; 243:60-76. [DOI: 10.1016/j.resp.2017.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/16/2017] [Accepted: 05/17/2017] [Indexed: 12/12/2022]
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37
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Cinelli E, Iovino L, Mutolo D. ATP and astrocytes play a prominent role in the control of the respiratory pattern generator in the lamprey. J Physiol 2017; 595:7063-7079. [PMID: 28734063 DOI: 10.1113/jp274749] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 07/21/2017] [Indexed: 01/04/2023] Open
Abstract
KEY POINTS The paratrigeminal respiratory group (pTRG) is responsible for the respiratory pattern generation in the lamprey. The role of ATP and astrocytes, known to control respiratory activity in mammals, was investigated in the lamprey respiratory network. ATP microinjected into the pTRG induces a biphasic response consisting of marked increases in respiratory frequency mediated by P2X receptors followed by a decrease in the respiratory motor output due to the ATP metabolite adenosine. We provide evidence that astrocytes are involved in the genesis of the normal respiratory pattern, ATP-induced responses and acidification-induced increases of the respiratory activity. The function of astrocytes in rhythmic networks appears to be phylogenetically conserved. ABSTRACT The role of ATP and astrocytes in respiratory rhythm modulation has been recently investigated in neonatal rodents. However, no information on the role of ATP and astrocytes within the respiratory network of the lamprey is available, particularly within the paratrigeminal respiratory group (pTRG), the proposed respiratory central pattern generator. To address these issues, the present study was carried out on isolated brainstems of the adult lamprey. Bath application of ATP caused marked increases in respiratory frequency followed by decreases in the respiratory motor output, mediated by the ATP metabolite adenosine at the level of the pTRG. Bath applications and microinjections of agonists and antagonists of purinergic receptors showed that ATP increased respiratory activity through an action on pTRG P2X receptors. To disclose the respiratory role of astrocytes, we used bath application of the gliotoxin aminoadipic acid, which dramatically depressed the respiratory motor output that, however, promptly recovered following glutamine application. Furthermore, the excitatory responses to ATP-γ-S (a non-hydrolysable ATP analogue), but not to substance P, microinjected into the pTRG, were abolished. Finally, we also demonstrated that acidification-induced increases in respiratory activity were ATP-independent, but mediated by the astrocytes' glutamate-glutamine cycle. The results show for the first time that ATP and especially astrocytes strongly contribute to the modulation of the lamprey respiratory pattern. Their role in the modulation or maintenance of rhythmic neuronal activities appears to be phylogenetically conserved.
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Affiliation(s)
- Elenia Cinelli
- Dipartimento di Medicina Sperimentale e Clinica, Sezione Scienze Fisiologiche, Università degli Studi di Firenze, Viale G.B. Morgagni 63, 50134, Firenze, Italy
| | - Ludovica Iovino
- Dipartimento di Medicina Sperimentale e Clinica, Sezione Scienze Fisiologiche, Università degli Studi di Firenze, Viale G.B. Morgagni 63, 50134, Firenze, Italy
| | - Donatella Mutolo
- Dipartimento di Medicina Sperimentale e Clinica, Sezione Scienze Fisiologiche, Università degli Studi di Firenze, Viale G.B. Morgagni 63, 50134, Firenze, Italy
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38
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Adamsky A, Goshen I. Astrocytes in Memory Function: Pioneering Findings and Future Directions. Neuroscience 2017; 370:14-26. [PMID: 28571720 DOI: 10.1016/j.neuroscience.2017.05.033] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/05/2017] [Accepted: 05/19/2017] [Indexed: 12/29/2022]
Abstract
Astrocytes have been generally believed to perform mainly homeostatic and supportive functions for neurons in the central nervous system. Recently, a growing body of evidence suggests previously unrecognized and surprising functions for astrocytes, including regulation of synaptic formation, transmission and plasticity, all of which are considered as the infrastructure for information processing and memory formation and stabilization. This review discusses the involvement of astrocytes in memory functions and the possible mechanisms that may underlie it. We review the important breakthroughs obtained in this field, as well as some of the controversies that arose from the past difficulty to manipulate these cells in a cell type-specific and non-invasive manner. Finally, we present new research avenues based on the advanced tools becoming available in recent years: optogenetics and chemogenetics, and the potential ways in which these tools may further illuminate the role of astrocytes in memory processes.
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Affiliation(s)
- Adar Adamsky
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Givat Ram, Jerusalem 91904, Israel
| | - Inbal Goshen
- Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University, Givat Ram, Jerusalem 91904, Israel.
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39
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Ikeda K, Kawakami K, Onimaru H, Okada Y, Yokota S, Koshiya N, Oku Y, Iizuka M, Koizumi H. The respiratory control mechanisms in the brainstem and spinal cord: integrative views of the neuroanatomy and neurophysiology. J Physiol Sci 2016; 67:45-62. [PMID: 27535569 PMCID: PMC5368202 DOI: 10.1007/s12576-016-0475-y] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/22/2016] [Indexed: 12/17/2022]
Abstract
Respiratory activities are produced by medullary respiratory rhythm generators and are modulated from various sites in the lower brainstem, and which are then output as motor activities through premotor efferent networks in the brainstem and spinal cord. Over the past few decades, new knowledge has been accumulated on the anatomical and physiological mechanisms underlying the generation and regulation of respiratory rhythm. In this review, we focus on the recent findings and attempt to elucidate the anatomical and functional mechanisms underlying respiratory control in the lower brainstem and spinal cord.
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Affiliation(s)
- Keiko Ikeda
- Division of Biology, Hyogo College of Medicine, Nishinomiya, Hyogo, 663-8501, Japan.
| | - Kiyoshi Kawakami
- Division of Biology, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Tochigi, 329-0498, Japan
| | - Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, Shinagawa, Tokyo, 142-8555, Japan.
| | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Tokyo, 208-0011, Japan.
| | - Shigefumi Yokota
- Department of Anatomy and Morphological Neuroscience, Shimane University School of Medicine, Izumo, Shimane, 693-8501, Japan
| | - Naohiro Koshiya
- Cellular and Systems Neurobiology Section, NINDS, NIH, Bethesda, MD, 20892, USA.
| | - Yoshitaka Oku
- Department of Physiology, Hyogo College of Medicine, Nishinomiya, Hyogo, 663-8501, Japan.
| | - Makito Iizuka
- Department of Physiology, Showa University School of Medicine, Shinagawa, Tokyo, 142-8555, Japan.
| | - Hidehiko Koizumi
- Cellular and Systems Neurobiology Section, NINDS, NIH, Bethesda, MD, 20892, USA
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40
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Forsberg D, Horn Z, Tserga E, Smedler E, Silberberg G, Shvarev Y, Kaila K, Uhlén P, Herlenius E. CO2-evoked release of PGE2 modulates sighs and inspiration as demonstrated in brainstem organotypic culture. eLife 2016; 5. [PMID: 27377173 PMCID: PMC4974055 DOI: 10.7554/elife.14170] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 06/21/2016] [Indexed: 12/20/2022] Open
Abstract
Inflammation-induced release of prostaglandin E2 (PGE2) changes breathing patterns and the response to CO2 levels. This may have fatal consequences in newborn babies and result in sudden infant death. To elucidate the underlying mechanisms, we present a novel breathing brainstem organotypic culture that generates rhythmic neural network and motor activity for 3 weeks. We show that increased CO2 elicits a gap junction-dependent release of PGE2. This alters neural network activity in the preBötzinger rhythm-generating complex and in the chemosensitive brainstem respiratory regions, thereby increasing sigh frequency and the depth of inspiration. We used mice lacking eicosanoid prostanoid 3 receptors (EP3R), breathing brainstem organotypic slices and optogenetic inhibition of EP3R+/+ cells to demonstrate that the EP3R is important for the ventilatory response to hypercapnia. Our study identifies a novel pathway linking the inflammatory and respiratory systems, with implications for inspiration and sighs throughout life, and the ability to autoresuscitate when breathing fails. DOI:http://dx.doi.org/10.7554/eLife.14170.001 Humans and other mammals breathe air to absorb oxygen into the body and to remove carbon dioxide. We know that in a part of the brain called the brainstem, several regions work together to create breaths, but it is not clear precisely how this works. These regions adjust our breathing to the demands placed on the body by different activities, such as sleeping or exercising. Sometimes, especially in newborn babies, the brainstem’s monitoring of oxygen and carbon dioxide does not work properly, which can lead to abnormal breathing and possibly death. In the brain, cells called neurons form networks that can rapidly transfer information via electrical signals. Here, Forsberg et al. investigated the neural networks in the brainstem that generate and control breathing in mice. They used slices of mouse brainstem that had been kept alive in a dish in the laboratory. The slice contained an arrangement of neurons and supporting cells that allowed it to continue to produce patterns of electrical activity that are associated with breathing. Over a three-week period, Forsberg et al. monitored the activity of the cells and calculated how they were connected to each other. The experiments show that the neurons responsible for breathing were organized in a “small-world” network, in which the neurons are connected to each other directly or via small numbers of other neurons. Further experiments tested how various factors affect the behavior of the network. For example, carbon dioxide triggered the release of a small molecule called prostaglandin E2 from cells. This molecule is known to play a role in inflammation and fever. However, in the carbon dioxide sensing region of the brainstem it acted as a signaling molecule that increased activity. Therefore, inflammation could interfere with the body’s normal response to carbon dioxide and lead to potentially life-threatening breathing problems. Furthermore, prostaglandin E2 induced deeper breaths known as sighs, which may be vital for newborn babies to be able to take their first deep breaths of life. Future challenges include understanding how the brainstem neural networks generate breathing and translate this knowledge to improve the treatment of breathing difficulties in babies. DOI:http://dx.doi.org/10.7554/eLife.14170.002
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Affiliation(s)
- David Forsberg
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.,Karolinska University Hospital, Stockholm, Sweden
| | - Zachi Horn
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.,Karolinska University Hospital, Stockholm, Sweden
| | - Evangelia Tserga
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.,Karolinska University Hospital, Stockholm, Sweden
| | - Erik Smedler
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Gilad Silberberg
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Yuri Shvarev
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.,Karolinska University Hospital, Stockholm, Sweden
| | - Kai Kaila
- Department of Biosciences and Neuroscience Center, University of Helsinki, Helsinki, Finland
| | - Per Uhlén
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Eric Herlenius
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden.,Karolinska University Hospital, Stockholm, Sweden
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Koizumi H, Mosher B, Tariq MF, Zhang R, Koshiya N, Smith JC. Voltage-Dependent Rhythmogenic Property of Respiratory Pre-Bötzinger Complex Glutamatergic, Dbx1-Derived, and Somatostatin-Expressing Neuron Populations Revealed by Graded Optogenetic Inhibition. eNeuro 2016; 3:ENEURO. [PMID: 27275007 DOI: 10.1523/ENEURO.0081-16.2016] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Accepted: 05/12/2016] [Indexed: 11/21/2022] Open
Abstract
The rhythm of breathing in mammals, originating within the brainstem pre-Bötzinger complex (pre-BötC), is presumed to be generated by glutamatergic neurons, but this has not been directly demonstrated. Additionally, developmental expression of the transcription factor Dbx1 or expression of the neuropeptide somatostatin (Sst), has been proposed as a marker for the rhythmogenic pre-BötC glutamatergic neurons, but it is unknown whether these other two phenotypically defined neuronal populations are functionally equivalent to glutamatergic neurons with regard to rhythm generation. To address these problems, we comparatively investigated, by optogenetic approaches, the roles of pre-BötC glutamatergic, Dbx1-derived, and Sst-expressing neurons in respiratory rhythm generation in neonatal transgenic mouse medullary slices in vitro and also more intact adult perfused brainstem-spinal cord preparations in situ. We established three different triple-transgenic mouse lines with Cre-driven Archaerhodopsin-3 (Arch) expression selectively in glutamatergic, Dbx1-derived, or Sst-expressing neurons for targeted photoinhibition. In each line, we identified subpopulations of rhythmically active, Arch-expressing pre-BötC inspiratory neurons by whole-cell recordings in medullary slice preparations in vitro, and established that Arch-mediated hyperpolarization of these inspiratory neurons was laser power dependent with equal efficacy. By site- and population-specific graded photoinhibition, we then demonstrated that inspiratory frequency was reduced by each population with the same neuronal voltage-dependent frequency control mechanism in each state of the respiratory network examined. We infer that enough of the rhythmogenic pre-BötC glutamatergic neurons also have the Dbx1 and Sst expression phenotypes, and thus all three phenotypes share the same voltage-dependent frequency control property.
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Fukushi I, Takeda K, Yokota S, Hasebe Y, Sato Y, Pokorski M, Horiuchi J, Okada Y. Effects of arundic acid, an astrocytic modulator, on the cerebral and respiratory functions in severe hypoxia. Respir Physiol Neurobiol 2016; 226:24-9. [DOI: 10.1016/j.resp.2015.11.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 12/18/2022]
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43
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Abstract
We propose a coupled system of fast and slow phase oscillators. We observe two-step transitions to quasiperiodic motions by direct numerical simulations of this coupled oscillator system. A low-dimensional equation for order parameters is derived using the Ott-Antonsen ansatz. The applicability of the ansatz is checked by the comparison of numerical results of the coupled oscillator system and the reduced low-dimensional equation. We investigate further several interesting phenomena in which mutual interactions between the fast and slow oscillators play an essential role. Fast oscillations appear intermittently as a result of excitatory interactions with slow oscillators in a certain parameter range. Slow oscillators experience an oscillator-death phenomenon owing to their interaction with fast oscillators. This oscillator death is explained as a result of saddle-node bifurcation in a simple phase equation obtained using the temporal average of the fast oscillations. Finally, we show macroscopic synchronization of the order 1:m between the slow and fast oscillators.
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Affiliation(s)
- Hidetsugu Sakaguchi
- Department of Applied Science for Electronics and Materials, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
| | - Takayuki Okita
- Department of Applied Science for Electronics and Materials, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
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Takeda K, Pokorski M, Sato Y, Oyamada Y, Okada Y. Respiratory Toxicity of Dimethyl Sulfoxide. In: Pokorski M, editor. Respirology. Cham: Springer International Publishing; 2016. pp. 89-96. [DOI: 10.1007/5584_2015_187] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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45
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Tani M, Yazawa I, Ikeda K, Kawakami K, Onimaru H. Long-lasting facilitation of respiratory rhythm by treatment with TRPA1 agonist, cinnamaldehyde. J Neurophysiol 2015; 114:989-98. [PMID: 26108952 PMCID: PMC4725117 DOI: 10.1152/jn.00282.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 06/11/2015] [Indexed: 11/22/2022] Open
Abstract
The transient receptor potential (TRP) channels are widely distributed in the central nervous system (CNS) and peripheral nervous system. We examined the effects of TRP ankyrin 1 (TRPA1) agonists (cinnamaldehyde and allyl isothiocyanate) on respiratory rhythm generation in brainstem-spinal cord preparations from newborn rats [postnatal days 0-3 (P0-P3)] and in in situ-perfused preparations from juvenile rats (P11-P13). Preparations were superfused with modified Krebs solution at 25-26°C, and activity of inspiratory C4 ventral root (or phrenic nerve) was monitored. In the newborn rat, an in vitro preparation of cinnamaldehyde (0.5 mM) induced typically biphasic responses in C4 rate: an initial short increase and subsequent decrease, then a gradual recovery of rhythm during 15 min of bath application. After washout, the respiratory rhythm rate further increased, remaining 200% of control for >120 min, indicating long-lasting facilitation. Allyl isothiocyanate induced effects similar to those of cinnamaldehyde. The long-lasting facilitation of respiratory rhythm was partially antagonized by the TRPA1 antagonist HC-030031 (10 μM). We obtained similar long-lasting facilitation in an in situ-perfused reparation from P11-P13 rats. On the basis of results from transection experiments of the rostral medulla and whole-cell recordings from preinspiratory neurons in the parafacial respiratory group (pFRG), we suggest that the rostral medulla, including the pFRG, is important to the induction of long-lasting facilitation. A histochemical analysis demonstrated a wide distribution of TRPA1 channel-positive cells in the reticular formation of the medulla, including the pFRG. Our findings suggest that TRPA1 channel activation could induce long-lasting facilitation of respiratory rhythm and provide grounds for future study on the roles of TRPA1 channels in the CNS.
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Affiliation(s)
- Mariho Tani
- Department of Physiology, Showa University School of Medicine, Tokyo, Japan
| | - Itaru Yazawa
- Department of Anatomy, Showa University School of Medicine, Tokyo, Japan
| | - Keiko Ikeda
- Division of Biology, Hyogo College of Medicine, Hyogo, Japan; and
| | - Kiyoshi Kawakami
- Division of Biology, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, Tokyo, Japan;
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46
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Natsubori A, Takata N, Tanaka KF. Observation and manipulation of glial cell function by virtue of sufficient probe expression. Front Cell Neurosci 2015; 9:176. [PMID: 26005405 PMCID: PMC4424858 DOI: 10.3389/fncel.2015.00176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 04/21/2015] [Indexed: 01/22/2023] Open
Abstract
The development of gene-encoded indicators and actuators to observe and manipulate cellular functions is being advanced and investigated. Expressing these probe molecules in glial cells is expected to enable observation and manipulation of glial cell activity, leading to elucidate the behaviors and causal roles of glial cells. The first step toward understanding glial cell functions is to express the probes in sufficient amounts, and the Knockin-mediated ENhanced Gene Expression (KENGE)-tet system provides a strategy for achieving this. In the present article, three examples of KENGE-tet system application are reviewed: depolarization of oligodendrocytes, intracellular acidification of astrocytes, and observation of intracellular calcium levels in the fine processes of astrocytes.
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Affiliation(s)
- Akiyo Natsubori
- Department of Neuropsychiatry, School of Medicine, Keio University Tokyo, Japan
| | - Norio Takata
- Department of Neuropsychiatry, School of Medicine, Keio University Tokyo, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, School of Medicine, Keio University Tokyo, Japan
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Morquette P, Verdier D, Kadala A, Féthière J, Philippe AG, Robitaille R, Kolta A. An astrocyte-dependent mechanism for neuronal rhythmogenesis. Nat Neurosci 2015; 18:844-54. [PMID: 25938883 DOI: 10.1038/nn.4013] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 04/02/2015] [Indexed: 12/22/2022]
Abstract
Communication between neurons rests on their capacity to change their firing pattern to encode different messages. For several vital functions, such as respiration and mastication, neurons need to generate a rhythmic firing pattern. Here we show in the rat trigeminal sensori-motor circuit for mastication that this ability depends on regulation of the extracellular Ca(2+) concentration ([Ca(2+)]e) by astrocytes. In this circuit, astrocytes respond to sensory stimuli that induce neuronal rhythmic activity, and their blockade with a Ca(2+) chelator prevents neurons from generating a rhythmic bursting pattern. This ability is restored by adding S100β, an astrocytic Ca(2+)-binding protein, to the extracellular space, while application of an anti-S100β antibody prevents generation of rhythmic activity. These results indicate that astrocytes regulate a fundamental neuronal property: the capacity to change firing pattern. These findings may have broad implications for many other neural networks whose functions depend on the generation of rhythmic activity.
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Affiliation(s)
- Philippe Morquette
- Département de Neurosciences and Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Dorly Verdier
- Département de Neurosciences and Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Aklesso Kadala
- Département de Neurosciences and Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - James Féthière
- Faculté de Pharmacie, Université de Montréal, Montréal, Québec, Canada
| | - Antony G Philippe
- 1] Faculté des Sciences du Sport, Université Montpellier 1, Montpellier, France. [2] Institut National de la Recherche Agronomique, UMR866 Dynamique Musculaire Et Métabolisme, Montpellier, France
| | - Richard Robitaille
- Département de Neurosciences and Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada
| | - Arlette Kolta
- 1] Département de Neurosciences and Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec, Canada. [2] Faculté de Médecine Dentaire and Réseau de Recherche en Santé Bucco-dentaire et Osseuse du Fonds de Recherche Québec-Santé, Université de Montréal, Montréal, Québec, Canada
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48
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Oke Y, Boiroux D, Miwakeichi F, Oku Y. Stochastic activation among inspiratory cells in the pre-Bötzinger complex of the rat medulla revealed by Ca2+ imaging. Neurosci Lett 2015; 595:12-7. [DOI: 10.1016/j.neulet.2015.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 04/01/2015] [Accepted: 04/02/2015] [Indexed: 11/17/2022]
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49
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Hososhima S, Sakai S, Ishizuka T, Yawo H. Kinetic evaluation of photosensitivity in bi-stable variants of chimeric channelrhodopsins. PLoS One 2015; 10:e0119558. [PMID: 25789474 PMCID: PMC4366085 DOI: 10.1371/journal.pone.0119558] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 01/14/2015] [Indexed: 11/30/2022] Open
Abstract
Channelrhodopsin-1 and 2 (ChR1 and ChR2) form cation channels that are gated by light through an unknown mechanism. We tested the DC-gate hypothesis that C167 and D195 are involved in the stabilization of the cation-permeable state of ChRWR/C1C2 which consists of TM1-5 of ChR1 and TM6-7 of ChR2 and ChRFR which consists of TM1-2 of ChR1 and TM3-7 of ChR2. The cation permeable state of each ChRWR and ChRFR was markedly prolonged in the order of several tens of seconds when either C167 or D195 position was mutated to alanine (A). Therefore, the DC-gate function was conserved among these chimeric ChRs. We next investigated the kinetic properties of the ON/OFF response of these bi-stable ChR mutants as they are important in designing the photostimulation protocols for the optogenetic manipulation of neuronal activities. The turning-on rate constant of each photocurrent followed a linear relationship to 0–0.12 mWmm−2 of blue LED light or to 0–0.33 mWmm−2 of cyan LED light. Each photocurrent of bi-stable ChR was shut off to the non-conducting state by yellow or orange LED light in a manner dependent on the irradiance. As the magnitude of the photocurrent was mostly determined by the turning-on rate constant and the irradiation time, the minimal irradiance that effectively evoked an action potential (threshold irradiance) was decreased with time only if the neuron, which expresses bi-stable ChRs, has a certain large membrane time constant (eg. τm > 20 ms). On the other hand, in another group of neurons, the threshold irradiance was not dependent on the irradiation time. Based on these quantitative data, we would propose that these bi-stable ChRs would be most suitable for enhancing the intrinsic activity of excitatory pyramidal neurons at a minimal magnitude of irradiance.
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Affiliation(s)
- Shoko Hososhima
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Core Research of Evolutional Science & Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan
| | - Seiichiro Sakai
- Core Research of Evolutional Science & Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan
- Laboratory for Local Neuronal Circuits, Brain Science Institute, RIKEN, Wako, Japan
| | - Toru Ishizuka
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Core Research of Evolutional Science & Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan
| | - Hiromu Yawo
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
- Core Research of Evolutional Science & Technology (CREST), Japan Science and Technology Agency (JST), Tokyo, Japan
- Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Japan
- * E-mail:
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50
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Oku Y, Fresemann J, Miwakeichi F, Hülsmann S. Respiratory calcium fluctuations in low-frequency oscillating astrocytes in the pre-Bötzinger complex. Respir Physiol Neurobiol 2015; 226:11-7. [PMID: 25747384 DOI: 10.1016/j.resp.2015.02.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 02/20/2015] [Accepted: 02/22/2015] [Indexed: 11/18/2022]
Abstract
Astrocytes have been found to modulate neuronal activity through calcium-dependent signaling in various brain regions. However, whether astrocytes of the pre-Bötzinger complex (preBötC) exhibit respiratory rhythmic fluctuations is still controversial. Here we evaluated calcium-imaging experiments within preBötC in rhythmically active medullary slices from TgN(hGFAP-EGFP) mice using advanced analyses. 13.8% of EGFP-negative cells, putative neurons, showed rhythmic fluorescent changes that were highly correlated to the respiratory rhythmic fluctuation (cross-correlation coefficient>0.5 and dF/F>0.2%). In contrast, a considerable number of astrocyte somata exhibited synchronized low-frequency (<0.03Hz) calcium oscillations. After band-pass filtering, signals that irregularly preceded the calcium signal of EGFP-negative cells were observed in 10.2% of astrocytes, indicating a functional coupling between astrocytes and neurons in preBötC. A model simulation confirmed that such preinspiratory astrocytic signals can arise from coupled neuronal and astrocytic oscillators, supporting a concept that slow oscillatory changes of astrocytic functions modulate neighboring neuronal activity to add variability in respiratory rhythm.
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Affiliation(s)
- Yoshitaka Oku
- Department of Physiology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan.
| | - Jens Fresemann
- Clinic for Anesthesiology, Laboratory for Experimental Neuroanesthesiology, University Hospital Göttingen, 37099 Göttingen, Germany
| | - Fumikazu Miwakeichi
- Department of Statistical Modeling, The Institute of Statistical Mathematics, Tokyo 190-8562, Japan; Department of Statistical Science, School of Multidisciplinary Sciences, The Graduate University for Advanced Studies, Tokyo 190-8562, Japan
| | - Swen Hülsmann
- Clinic for Anesthesiology, Laboratory for Experimental Neuroanesthesiology, University Hospital Göttingen, 37099 Göttingen, Germany; DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.
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