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Su Y, Xu J, Zhu Z, Chin J, Xu L, Yu H, Nudell V, Dash B, Moya EA, Ye L, Nimmerjahn A, Sun X. Brainstem Dbh + neurons control allergen-induced airway hyperreactivity. Nature 2024; 631:601-609. [PMID: 38987587 DOI: 10.1038/s41586-024-07608-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 05/24/2024] [Indexed: 07/12/2024]
Abstract
Exaggerated airway constriction triggered by repeated exposure to allergen, also called hyperreactivity, is a hallmark of asthma. Whereas vagal sensory neurons are known to function in allergen-induced hyperreactivity1-3, the identity of downstream nodes remains poorly understood. Here we mapped a full allergen circuit from the lung to the brainstem and back to the lung. Repeated exposure of mice to inhaled allergen activated the nuclei of solitary tract (nTS) neurons in a mast cell-, interleukin-4 (IL-4)- and vagal nerve-dependent manner. Single-nucleus RNA sequencing, followed by RNAscope assay at baseline and allergen challenges, showed that a Dbh+ nTS population is preferentially activated. Ablation or chemogenetic inactivation of Dbh+ nTS neurons blunted hyperreactivity whereas chemogenetic activation promoted it. Viral tracing indicated that Dbh+ nTS neurons project to the nucleus ambiguus (NA) and that NA neurons are necessary and sufficient to relay allergen signals to postganglionic neurons that directly drive airway constriction. Delivery of noradrenaline antagonists to the NA blunted hyperreactivity, suggesting noradrenaline as the transmitter between Dbh+ nTS and NA. Together, these findings provide molecular, anatomical and functional definitions of key nodes of a canonical allergen response circuit. This knowledge informs how neural modulation could be used to control allergen-induced airway hyperreactivity.
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Affiliation(s)
- Yujuan Su
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jinhao Xu
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Department of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Ziai Zhu
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jisun Chin
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Le Xu
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Haoze Yu
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Victoria Nudell
- Department of Neuroscience, Scripps Research Institute, La Jolla, CA, USA
| | - Barsha Dash
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Esteban A Moya
- Division of Pulmonary, Critical Care & Sleep Medicine, Department of Medicine, University of California, San Diego, CA, USA
| | - Li Ye
- Department of Neuroscience, Scripps Research Institute, La Jolla, CA, USA
| | - Axel Nimmerjahn
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Xin Sun
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, USA.
- Department of Biological Sciences, University of California San Diego, La Jolla, CA, USA.
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2
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Prescott S. The wonderful wanderer. Semin Cell Dev Biol 2024; 159-160:62-63. [PMID: 38335774 DOI: 10.1016/j.semcdb.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2024]
Affiliation(s)
- Sara Prescott
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Picower Institute for Learning and Memory, Cambridge, MA, USA.
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3
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Gruber T, Lechner F, Krieger JP, García-Cáceres C. Neuroendocrine gut-brain signaling in obesity. Trends Endocrinol Metab 2024:S1043-2760(24)00120-6. [PMID: 38821753 DOI: 10.1016/j.tem.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 04/29/2024] [Accepted: 05/03/2024] [Indexed: 06/02/2024]
Abstract
The past decades have witnessed the rise and fall of several, largely unsuccessful, therapeutic attempts to bring the escalating obesity pandemic to a halt. Looking back to look ahead, the field has now put its highest hopes in translating insights from how the gastrointestinal (GI) tract communicates with the brain to calibrate behavior, physiology, and metabolism. A major focus of this review is to summarize the latest advances in comprehending the neuroendocrine aspects of this so-called 'gut-brain axis' and to explore novel concepts, cutting-edge technologies, and recent paradigm-shifting experiments. These exciting insights continue to refine our understanding of gut-brain crosstalk and are poised to promote the development of additional therapeutic avenues at the dawn of a new era of antiobesity therapeutics.
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Affiliation(s)
- Tim Gruber
- Department of Metabolism and Nutritional Programming, Van Andel Institute, Grand Rapids, MI 49506, USA; Department of Epigenetics, Van Andel Institute, Grand Rapids, MI 49506, USA; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
| | - Franziska Lechner
- German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany
| | - Jean-Philippe Krieger
- Institute of Veterinary Pharmacology and Toxicology, University of Zurich-Vetsuisse, 8057 Zurich, Switzerland; Institute of Neuroscience and Physiology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Cristina García-Cáceres
- German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764 Neuherberg, Germany; Medizinische Klinik und Poliklinik IV, Klinikum der Universität, Ludwig-Maximilians-Universität München, 80336 Munich, Germany.
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4
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Wood CP, Alvarez C, DiPatrizio NV. Cholinergic Neurotransmission Controls Orexigenic Endocannabinoid Signaling in the Gut in Diet-Induced Obesity. J Neurosci 2024; 44:e0813232024. [PMID: 38594069 PMCID: PMC11097264 DOI: 10.1523/jneurosci.0813-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 03/12/2024] [Accepted: 03/30/2024] [Indexed: 04/11/2024] Open
Abstract
The brain bidirectionally communicates with the gut to control food intake and energy balance, which becomes dysregulated in obesity. For example, endocannabinoid (eCB) signaling in the small-intestinal (SI) epithelium is upregulated in diet-induced obese (DIO) mice and promotes overeating by a mechanism that includes inhibiting gut-brain satiation signaling. Upstream neural and molecular mechanism(s) involved in overproduction of orexigenic gut eCBs in DIO, however, are unknown. We tested the hypothesis that overactive parasympathetic signaling at the muscarinic acetylcholine receptors (mAChRs) in the SI increases biosynthesis of the eCB, 2-arachidonoyl-sn-glycerol (2-AG), which drives hyperphagia via local CB1Rs in DIO. Male mice were maintained on a high-fat/high-sucrose Western-style diet for 60 d, then administered several mAChR antagonists 30 min prior to tissue harvest or a food intake test. Levels of 2-AG and the activity of its metabolic enzymes in the SI were quantitated. DIO mice, when compared to those fed a low-fat/no-sucrose diet, displayed increased expression of cFos protein in the dorsal motor nucleus of the vagus, which suggests an increased activity of efferent cholinergic neurotransmission. These mice exhibited elevated levels of 2-AG biosynthesis in the SI, that was reduced to control levels by mAChR antagonists. Moreover, the peripherally restricted mAChR antagonist, methylhomatropine bromide, and the peripherally restricted CB1R antagonist, AM6545, reduced food intake in DIO mice for up to 24 h but had no effect in mice conditionally deficient in SI CB1Rs. These results suggest that hyperactivity at mAChRs in the periphery increases formation of 2-AG in the SI and activates local CB1Rs, which drives hyperphagia in DIO.
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Affiliation(s)
- Courtney P Wood
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California 92521
- University of California Riverside Center for Cannabinoid Research, Riverside, California 92521
| | - Camila Alvarez
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California 92521
- University of California Riverside Center for Cannabinoid Research, Riverside, California 92521
| | - Nicholas V DiPatrizio
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, California 92521
- University of California Riverside Center for Cannabinoid Research, Riverside, California 92521
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5
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Kaneko T, Boulanger-Weill J, Isabella AJ, Moens CB. Position-independent functional refinement within the vagus motor topographic map. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.11.557289. [PMID: 37745606 PMCID: PMC10515832 DOI: 10.1101/2023.09.11.557289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Motor neurons in the central nervous system often lie in a continuous topographic map, where neurons that innervate different body parts are spatially intermingled. This is the case for the efferent neurons of the vagus nerve, which innervate diverse muscle and organ targets in the head and viscera for brain-body communication. It remains elusive how neighboring motor neurons with different fixed peripheral axon targets develop the separate somatodendritic (input) connectivity they need to generate spatially precise body control. Here we show that vagus motor neurons in the zebrafish indeed generate spatially appropriate peripheral responses to focal sensory stimulation even when they are transplanted into ectopic positions within the topographic map, indicating that circuit refinement occurs after the establishment of coarse topography. Refinement depends on motor neuron synaptic transmission, suggesting that an experience-dependent periphery-to-brain feedback mechanism establishes specific input connectivity amongst intermingled motor populations.
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Affiliation(s)
- Takuya Kaneko
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, Washington 98109, USA
| | - Jonathan Boulanger-Weill
- Department of Molecular and Cellular Biology, Faculty of Arts and Sciences, Harvard University, Cambridge, MA 02138, USA
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Institut de la Vision, Paris, France
| | - Adam J Isabella
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, Washington 98109, USA
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Cecilia B Moens
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, Washington 98109, USA
- Lead contact
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Richter CF, Skibicka KP, Meyer U, Rohrmann S, Krieger JP. A vagal influence on schizophrenia? A nationwide retrospective cohort of vagotomized individuals. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.30.24301418. [PMID: 38352405 PMCID: PMC10862985 DOI: 10.1101/2024.01.30.24301418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/19/2024]
Abstract
Background and Objectives Emerging preclinical evidence suggests that vagal signals contribute to the development of schizophrenia-related abnormalities in brain and behavior. Whether vagal communication in general, and its impairment in particular, is a risk factor for schizophrenia in humans remains, however, unclear. Vagotomy, the surgical lesion of the vagus nerve, was routinely performed as a treatment for peptic ulcer before modern treatment options were available. Hence, the primary aim of this study was to investigate whether vagotomy modulates the subsequent risk of developing schizophrenia. Moreover, given the existence of diverse vagotomy techniques (i.e., "truncal" or "selective"), our secondary goal was to test whether the extent of denervation modulates the risk of schizophrenia. Methods Using a nationwide retrospective matched cohort design, we identified 8,315 vagotomized individuals from the Swedish National Patient Register during the period 1970-2020 and 40,855 non-vagotomized individuals matching for age, sex and type of peptic ulcer. The risk of being diagnosed with schizophrenia and associated psychoses (ICD10 codes F20-29) was analyzed using Cox proportional hazards regression models, including death as competing risk. Results When considering all types of vagotomy together, vagotomy was not significantly associated with schizophrenia (HR: 0.91 [0.72; 1.16]). However, truncal vagotomy (which denervates all subdiaphragmatic organs) significantly increased the risk of developing schizophrenia by 69% (HR: 1.69 [1.08; 2.64]), whereas selective vagotomy (which only denervates the stomach) showed no significant association (HR: 0.80 [0.61; 1.04]). Discussion Our results provide epidemiological support for the hypothesis that impairments in vagal functions could increase the risk of schizophrenia. Notably, the finding that truncal but not selective vagotomy is associated with an increased risk of schizophrenia raises the possibility that the activity of subdiaphragmatic non-gastric vagal branches may be of particular relevance for the development of schizophrenia.
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Affiliation(s)
- Cornelia F Richter
- Institute of Veterinary Pharmacology and Toxicology, University of Zurich-Vetsuisse, Switzerland
| | - Karolina P Skibicka
- Institute of Neuroscience and Physiology, University of Gothenburg, Sweden
- Department of Nutritional Sciences, Pennsylvania State University, State College, PA, United States
| | - Urs Meyer
- Institute of Veterinary Pharmacology and Toxicology, University of Zurich-Vetsuisse, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Switzerland
| | - Sabine Rohrmann
- Division of Chronic Disease Epidemiology, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Switzerland
| | - Jean-Philippe Krieger
- Institute of Veterinary Pharmacology and Toxicology, University of Zurich-Vetsuisse, Switzerland
- Institute of Neuroscience and Physiology, University of Gothenburg, Sweden
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7
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Chen J, Lai X, Song Y, Su X. Neuroimmune recognition and regulation in the respiratory system. Eur Respir Rev 2024; 33:240008. [PMID: 38925790 PMCID: PMC11216688 DOI: 10.1183/16000617.0008-2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/16/2024] [Indexed: 06/28/2024] Open
Abstract
Neuroimmune recognition and regulation in the respiratory system is a complex and highly coordinated process involving interactions between the nervous and immune systems to detect and respond to pathogens, pollutants and other potential hazards in the respiratory tract. This interaction helps maintain the health and integrity of the respiratory system. Therefore, understanding the complex interactions between the respiratory nervous system and immune system is critical to maintaining lung health and developing treatments for respiratory diseases. In this review, we summarise the projection distribution of different types of neurons (trigeminal nerve, glossopharyngeal nerve, vagus nerve, spinal dorsal root nerve, sympathetic nerve) in the respiratory tract. We also introduce several types of cells in the respiratory epithelium that closely interact with nerves (pulmonary neuroendocrine cells, brush cells, solitary chemosensory cells and tastebuds). These cells are primarily located at key positions in the respiratory tract, where nerves project to them, forming neuroepithelial recognition units, thus enhancing the ability of neural recognition. Furthermore, we summarise the roles played by these different neurons in sensing or responding to specific pathogens (influenza, severe acute respiratory syndrome coronavirus 2, respiratory syncytial virus, human metapneumovirus, herpes viruses, Sendai parainfluenza virus, Mycobacterium tuberculosis, Pseudomonas aeruginosa, Staphylococcus aureus, amoebae), allergens, atmospheric pollutants (smoking, exhaust pollution), and their potential roles in regulating interactions among different pathogens. We also summarise the prospects of bioelectronic medicine as a third therapeutic approach following drugs and surgery, as well as the potential mechanisms of meditation breathing as an adjunct therapy.
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Affiliation(s)
- Jie Chen
- Shanghai Key Laboratory of Lung Inflammation and Injury, Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
- Unit of Respiratory Infection and Immunity, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
- These authors contributed equally to this work
| | - Xiaoyun Lai
- Unit of Respiratory Infection and Immunity, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
- These authors contributed equally to this work
| | - Yuanlin Song
- Shanghai Key Laboratory of Lung Inflammation and Injury, Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiao Su
- Unit of Respiratory Infection and Immunity, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
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8
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Isabella AJ, Moens CB. Development and regeneration of the vagus nerve. Semin Cell Dev Biol 2024; 156:219-227. [PMID: 37537116 PMCID: PMC10830892 DOI: 10.1016/j.semcdb.2023.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 07/13/2023] [Accepted: 07/20/2023] [Indexed: 08/05/2023]
Abstract
The vagus nerve, with its myriad constituent axon branches and innervation targets, has long been a model of anatomical complexity in the nervous system. The branched architecture of the vagus nerve is now appreciated to be highly organized around the topographic and/or molecular identities of the neurons that innervate each target tissue. However, we are only just beginning to understand the developmental mechanisms by which heterogeneous vagus neuron identity is specified, patterned, and used to guide the axons of particular neurons to particular targets. Here, we summarize our current understanding of the complex topographic and molecular organization of the vagus nerve, the developmental basis of neuron specification and patterned axon guidance that supports this organization, and the regenerative mechanisms that promote, or inhibit, the restoration of vagus nerve organization after nerve damage. Finally, we highlight key unanswered questions in these areas and discuss potential strategies to address these questions.
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Affiliation(s)
- Adam J Isabella
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Cecilia B Moens
- Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA.
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9
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Strain MM, Conley NJ, Kauffman LS, Espinoza L, Fedorchak S, Martinez PC, Crook ME, Jalil M, Hodes GE, Abbott SB, Güler AD, Campbell JN, Boychuk CR. Dorsal motor vagal neurons can elicit bradycardia and reduce anxiety-like behavior. iScience 2024; 27:109137. [PMID: 38420585 PMCID: PMC10901094 DOI: 10.1016/j.isci.2024.109137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 12/16/2023] [Accepted: 02/01/2024] [Indexed: 03/02/2024] Open
Abstract
Cardiovagal neurons (CVNs) innervate cardiac ganglia through the vagus nerve to control cardiac function. Although the cardioinhibitory role of CVNs in nucleus ambiguus (CVNNA) is well established, the nature and functionality of CVNs in dorsal motor nucleus of the vagus (CVNDMV) is less clear. We therefore aimed to characterize CVNDMV anatomically, physiologically, and functionally. Optogenetically activating cholinergic DMV neurons resulted in robust bradycardia through peripheral muscarinic (parasympathetic) and nicotinic (ganglionic) acetylcholine receptors, but not beta-1-adrenergic (sympathetic) receptors. Retrograde tracing from the cardiac fat pad labeled CVNNA and CVNDMV through the vagus nerve. Using whole-cell patch-clamp, CVNDMV demonstrated greater hyperexcitability and spontaneous action potential firing ex vivo despite similar resting membrane potentials, compared to CVNNA. Chemogenetically activating DMV also caused significant bradycardia with a correlated reduction in anxiety-like behavior. Thus, DMV contains uniquely hyperexcitable CVNs and is capable of cardioinhibition and robust anxiolysis.
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Affiliation(s)
- Misty M. Strain
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | | | - Lily S. Kauffman
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Liliana Espinoza
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Stephanie Fedorchak
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
| | | | - Maisie E. Crook
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Maira Jalil
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Georgia E. Hodes
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Stephen B.G. Abbott
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - Ali D. Güler
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - John N. Campbell
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Carie R. Boychuk
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX, USA
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, USA
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10
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Borgmann D, Fenselau H. Vagal pathways for systemic regulation of glucose metabolism. Semin Cell Dev Biol 2024; 156:244-252. [PMID: 37500301 DOI: 10.1016/j.semcdb.2023.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 06/20/2023] [Accepted: 07/20/2023] [Indexed: 07/29/2023]
Abstract
Maintaining blood glucose at an appropriate physiological level requires precise coordination of multiple organs and tissues. The vagus nerve bidirectionally connects the central nervous system with peripheral organs crucial to glucose mobilization, nutrient storage, and food absorption, thereby presenting a key pathway for the central control of blood glucose levels. However, the precise mechanisms by which vagal populations that target discrete tissues participate in glucoregulation are much less clear. Here we review recent advances unraveling the cellular identity, neuroanatomical organization, and functional contributions of both vagal efferents and vagal afferents in the control of systemic glucose metabolism. We focus on their involvement in relaying glucoregulatory cues from the brain to peripheral tissues, particularly the pancreatic islet, and by sensing and transmitting incoming signals from ingested food to the brain. These recent findings - largely driven by advances in viral approaches, RNA sequencing, and cell-type selective manipulations and tracings - have begun to clarify the precise vagal neuron populations involved in the central coordination of glucose levels, and raise interesting new possibilities for the treatment of glucose metabolism disorders such as diabetes.
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Affiliation(s)
- Diba Borgmann
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Physical Activity Research (CFAS), Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Henning Fenselau
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50937 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Straße 26, Cologne 50931, Germany.
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11
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Coverdell TC, Abbott SBG, Campbell JN. Molecular cell types as functional units of the efferent vagus nerve. Semin Cell Dev Biol 2024; 156:210-218. [PMID: 37507330 PMCID: PMC10811285 DOI: 10.1016/j.semcdb.2023.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 07/20/2023] [Accepted: 07/20/2023] [Indexed: 07/30/2023]
Abstract
The vagus nerve vitally connects the brain and body to coordinate digestive, cardiorespiratory, and immune functions. Its efferent neurons, which project their axons from the brainstem to the viscera, are thought to comprise "functional units" - neuron populations dedicated to the control of specific vagal reflexes or organ functions. Previous research indicates that these functional units differ from one another anatomically, neurochemically, and physiologically but have yet to define their identity in an experimentally tractable way. However, recent work with genetic technology and single-cell genomics suggests that genetically distinct subtypes of neurons may be the functional units of the efferent vagus. Here we review how these approaches are revealing the organizational principles of the efferent vagus in unprecedented detail.
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Affiliation(s)
- Tatiana C Coverdell
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA 22903, USA
| | - Stephen B G Abbott
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22903, USA
| | - John N Campbell
- Department of Biology, University of Virginia, Charlottesville, VA 22903, USA.
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12
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Teckentrup V, Kroemer NB. Mechanisms for survival: vagal control of goal-directed behavior. Trends Cogn Sci 2024; 28:237-251. [PMID: 38036309 DOI: 10.1016/j.tics.2023.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 12/02/2023]
Abstract
Survival is a fundamental physiological drive, and neural circuits have evolved to prioritize actions that meet the energy demands of the body. This fine-tuning of goal-directed actions based on metabolic states ('allostasis') is deeply rooted in our brain, and hindbrain nuclei orchestrate the vital communication between the brain and body through the vagus nerve. Despite mounting evidence for vagal control of allostatic behavior in animals, its broader function in humans is still contested. Based on stimulation studies, we propose that the vagal afferent pathway supports transitions between survival modes by gating the integration of ascending bodily signals, thereby regulating reward-seeking. By reconceptualizing vagal signals as catalysts for goal-directed behavior, our perspective opens new avenues for theory-driven translational work in mental disorders.
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Affiliation(s)
- Vanessa Teckentrup
- Department of Psychiatry and Psychotherapy, Tübingen Center for Mental Health, University of Tübingen, 72076 Tübingen, Germany; School of Psychology and Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Nils B Kroemer
- Department of Psychiatry and Psychotherapy, Tübingen Center for Mental Health, University of Tübingen, 72076 Tübingen, Germany; Section of Medical Psychology, Department of Psychiatry and Psychotherapy, Faculty of Medicine, University of Bonn, 53127 Bonn, Germany; German Center for Mental Health (DZPG), 72076 Tübingen, Germany.
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13
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Su Y, Xu J, Zhu Z, Chin J, Xu L, Yu H, Nudell V, Dash B, Moya EA, Ye L, Nimmerjahn A, Sun X. Brainstem Dbh+ Neurons Control Chronic Allergen-Induced Airway Hyperreactivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.02.04.527145. [PMID: 36778350 PMCID: PMC9915738 DOI: 10.1101/2023.02.04.527145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chronic exposure of the lung to irritants such as allergen is a primary cause of asthma characterized by exaggerated airway constriction, also called hyperreactivity, which can be life-threatening. Aside from immune cells, vagal sensory neurons are important for airway hyperreactivity 1-4 . However, the identity and signature of the downstream nodes of this adaptive circuit remains poorly understood. Here we show that a single population of Dbh + neurons in the nucleus of the solitary tract (nTS) of the brainstem, and downstream neurons in the nucleus ambiguous (NA), are both necessary and sufficient for chronic allergen-induced airway hyperreactivity. We found that repeated exposures of mice to inhaled allergen activates nTS neurons in a mast cell-, interleukin 4 (IL-4)-and vagal nerve-dependent manner. Single-nucleus RNA-seq of the nTS at baseline and following allergen challenges reveals that a Dbh + population is preferentially activated. Ablation or chemogenetic inactivation of Dbh + nTS neurons blunted, while chemogenetic activation promoted hyperreactivity. Viral tracing indicates that Dbh + nTS neurons, capable of producing norepinephrine, project to the NA, and NA neurons are necessary and sufficient to relay allergen signals to postganglionic neurons that then directly drive airway constriction. Focusing on transmitters, delivery of norepinephrine antagonists to the NA blunted allergen-induced hyperreactivity. Together, these findings provide molecular, anatomical and functional definitions of key nodes of a canonical allergen response circuit. The knowledge opens the possibility of targeted neural modulation as an approach to control refractory allergen-induced airway constriction.
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Berkhout JB, Poormoghadam D, Yi C, Kalsbeek A, Meijer OC, Mahfouz A. An integrated single-cell RNA-seq atlas of the mouse hypothalamic paraventricular nucleus links transcriptomic and functional types. J Neuroendocrinol 2024; 36:e13367. [PMID: 38281730 DOI: 10.1111/jne.13367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 11/30/2023] [Accepted: 12/30/2023] [Indexed: 01/30/2024]
Abstract
The hypothalamic paraventricular nucleus (PVN) is a highly complex brain region that is crucial for homeostatic regulation through neuroendocrine signaling, outflow of the autonomic nervous system, and projections to other brain areas. In the past years, single-cell datasets of the hypothalamus have contributed immensely to the current understanding of the diverse hypothalamic cellular composition. While the PVN has been adequately classified functionally, its molecular classification is currently still insufficient. To address this, we created a detailed atlas of PVN transcriptomic cell types by integrating various PVN single-cell datasets into a recently published hypothalamus single-cell transcriptome atlas. Furthermore, we functionally profiled transcriptomic cell types, based on relevant literature, existing retrograde tracing data, and existing single-cell data of a PVN-projection target region. Finally, we validated our findings with immunofluorescent stainings. In our PVN atlas dataset, we identify the well-known different neuropeptide types, each composed of multiple novel subtypes. We identify Avp-Tac1, Avp-Th, Oxt-Foxp1, Crh-Nr3c1, and Trh-Nfib as the most important neuroendocrine subtypes based on markers described in literature. To characterize the preautonomic functional population, we integrated a single-cell retrograde tracing study of spinally projecting preautonomic neurons into our PVN atlas. We identify these (presympathetic) neurons to cocluster with the Adarb2+ clusters in our dataset. Further, we identify the expression of receptors for Crh, Oxt, Penk, Sst, and Trh in the dorsal motor nucleus of the vagus, a key region that the pre-parasympathetic PVN neurons project to. Finally, we identify Trh-Ucn3 and Brs3-Adarb2 as some centrally projecting populations. In conclusion, our study presents a detailed overview of the transcriptomic cell types of the murine PVN and provides a first attempt to resolve functionality for the identified populations.
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Affiliation(s)
- J B Berkhout
- Division of Endocrinology, Department of Medicine, Leiden University Medical Centre, Leiden, The Netherlands
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
| | - D Poormoghadam
- Laboratory of Endocrinology, Department of Laboratory Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - C Yi
- Laboratory of Endocrinology, Department of Laboratory Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - A Kalsbeek
- Laboratory of Endocrinology, Department of Laboratory Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
- Department of Endocrinology and Metabolism, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - O C Meijer
- Division of Endocrinology, Department of Medicine, Leiden University Medical Centre, Leiden, The Netherlands
| | - A Mahfouz
- Department of Human Genetics, Leiden University Medical Centre, Leiden, The Netherlands
- Division of Pattern Recognition and Bioinformatics, Department of Intelligent Systems, Technical University Delft, Delft, The Netherlands
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15
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Wang Q, Caraballo SG, Rychkov G, McGovern AE, Mazzone SB, Brierley SM, Harrington AM. Comparative localization of colorectal sensory afferent central projections in the mouse spinal cord dorsal horn and caudal medulla dorsal vagal complex. J Comp Neurol 2024; 532:e25546. [PMID: 37837642 DOI: 10.1002/cne.25546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 09/04/2023] [Accepted: 10/03/2023] [Indexed: 10/16/2023]
Abstract
The distal colon and rectum (colorectum) are innervated by spinal and vagal afferent pathways. The central circuits into which vagal and spinal afferents relay colorectal nociceptive information remain to be comparatively assessed. To address this, regional colorectal retrograde tracing and colorectal distension (CRD)-evoked neuronal activation were used to compare the circuits within the dorsal vagal complex (DVC) and dorsal horn (thoracolumbar [TL] and lumbosacral [LS] spinal levels) into which vagal and spinal colorectal afferents project. Vagal afferent projections were observed in the nucleus tractus solitarius (NTS), area postrema (AP), and dorsal motor nucleus of the vagus (DMV), labeled from the rostral colorectum. In the NTS, projections were opposed to catecholamine and pontine parabrachial nuclei (PbN)-projecting neurons. Spinal afferent projections were labeled from rostral through to caudal aspects of the colorectum. In the dorsal horn, the number of neurons activated by CRD was linked to pressure intensity, unlike in the DVC. In the NTS, 13% ± 0.6% of CRD-activated neurons projected to the PbN. In the dorsal horn, at the TL spinal level, afferent input was associated with PbN-projecting neurons in lamina I (LI), with 63% ± 3.15% of CRD-activated neurons in LI projecting to the PbN. On the other hand, at the LS spinal level, only 18% ± 0.6% of CRD-activated neurons in LI projected to the PbN. The collective data identify differences in the central neuroanatomy that support the disparate roles of vagal and spinal afferent signaling in the facilitation and modulation of colorectal nociceptive responses.
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Affiliation(s)
- QingQing Wang
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
- Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Sonia Garcia Caraballo
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
- Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Grigori Rychkov
- Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
- School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Alice E McGovern
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Stuart B Mazzone
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Stuart M Brierley
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
- Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
- School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Andrea M Harrington
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
- Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
- School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
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16
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Hwang J, Okada J, Liu L, Pessin JE, Schwartz GJ, Jo YH. Loss of the brain-liver axis prevents hepatic steatosis in mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.03.565494. [PMID: 38260695 PMCID: PMC10802435 DOI: 10.1101/2023.11.03.565494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Hepatic lipid metabolism is regulated by the autonomic nervous system of the liver, with the sympathetic innervation being extensively studied, while the parasympathetic efferent innervation is less understood despite its potential importance. In this study, we investigate the consequences of disrupted brain-liver communication on hepatic lipid metabolism in mice exposed to obesogenic conditions. We found that a subset of hepatocytes and the bile duct are innervated by parasympathetic nerves originating from the dorsal motor nucleus of the vagus. The elimination of the brain-liver axis by deleting parasympathetic cholinergic neurons innervating the liver prevents hepatic steatosis and promots browning of inguinal white adipose tissue (ingWAT). The loss of the brain-liver axis also raises hepatic Cyp7b1 expression and fasting serum bile acid levels. Furthermore, knockdown of the G protein-coupled bile acid receptor 1 gene in ingWAT reverses the beneficial effects of the loss of the brain-liver axis, leading to the reappearance of hepatic steatosis in the experimental groups. However, deleting the brain-liver axis has a small but significant effect on body weight, which is accompanied by an increase in energy expenditure. Therefore, altering parasympathetic cholinergic innervation of the liver could offer a potential therapeutic approach for enhancing hepatic lipid metabolism in obesity and diabetes.
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17
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Akagi Y, Takayama Y, Nihashi Y, Yamashita A, Yoshida R, Miyamoto Y, Kida YS. Functional engineering of human iPSC-derived parasympathetic neurons enhances responsiveness to gastrointestinal hormones. FEBS Open Bio 2024; 14:63-78. [PMID: 38013211 PMCID: PMC10761937 DOI: 10.1002/2211-5463.13741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 11/15/2023] [Accepted: 11/23/2023] [Indexed: 11/29/2023] Open
Abstract
Food-derived biological signals are transmitted to the brain via peripheral nerves through the paracrine activity of gastrointestinal (GI) hormones. The signal transduction circuit of the brain-gut axis has been analyzed in animals; however, species-related differences and animal welfare concerns necessitate investigation using in vitro human experimental models. Here, we focused on the receptors of five GI hormones (CCK, GLP1, GLP2, PYY, and serotonin (5-HT)), and established human induced pluripotent stem cell (iPSC) lines that functionally expressed each receptor. Compared to the original iPSCs, iPSCs expressing one of the receptors did not show any differences in global mRNA expression, genomic stability, or differentiation capacities of the three germ layers. We induced parasympathetic neurons from these established iPSC lines to assess vagus nerve activity. We generated GI hormone receptor-expressing neurons (CCKAR, GLP1R, and NPY2R-neuron) and tested their responsiveness to each ligand using Ca2+ imaging and microelectrode array recording. GI hormone receptor-expressing neurons (GLP2R and HTR3A) were generated directly by gene induction into iPSC-derived peripheral nerve progenitors. These receptor-expressing neurons promise to contribute to a better understanding of how the body responds to GI hormones via the brain-gut axis, aid in drug development, and offer an alternative to animal studies.
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Affiliation(s)
- Yuka Akagi
- Cellular and Molecular Biotechnology Research InstituteNational Institute of Advanced Industrial Science and Technology (AIST)TsukubaJapan
- Tsukuba Life Science Innovation Program (T‐LSI), School of Comprehensive Human SciencesUniversity of TsukubaTsukubaJapan
| | - Yuzo Takayama
- Cellular and Molecular Biotechnology Research InstituteNational Institute of Advanced Industrial Science and Technology (AIST)TsukubaJapan
| | - Yuma Nihashi
- Cellular and Molecular Biotechnology Research InstituteNational Institute of Advanced Industrial Science and Technology (AIST)TsukubaJapan
| | - Azusa Yamashita
- Analytical Science Laboratories, Asahi Quality & Innovations, Ltd.MoriyaJapan
| | - Risa Yoshida
- Analytical Science Laboratories, Asahi Quality & Innovations, Ltd.MoriyaJapan
| | - Yasuhisa Miyamoto
- Analytical Science Laboratories, Asahi Quality & Innovations, Ltd.MoriyaJapan
| | - Yasuyuki S. Kida
- Cellular and Molecular Biotechnology Research InstituteNational Institute of Advanced Industrial Science and Technology (AIST)TsukubaJapan
- School of Integrative & Global Majors (SIGMA)University of TsukubaTsukubaJapan
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Jameson KG, Kazmi SA, Son C, Mazdeyasnan D, Leshan E, Vuong HE, Paramo J, Lopez-Romero A, Yang L, Schweizer FE, Hsiao EY. Vagal interoception of microbial metabolites from the small intestinal lumen. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.18.572257. [PMID: 38187610 PMCID: PMC10769238 DOI: 10.1101/2023.12.18.572257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
The vagus nerve is proposed to enable communication between the gut microbiome and brain, but activity-based evidence is lacking. Herein, we assess the extent of gut microbial influences on afferent vagal activity and metabolite signaling mechanisms involved. We find that mice reared without microbiota (germ-free, GF) exhibit decreased vagal afferent tone relative to conventionally colonized mice (specific pathogen-free, SPF), which is reversed by colonization with SPF microbiota. Perfusing non-absorbable antibiotics (ABX) into the small intestine of SPF mice, but not GF mice, acutely decreases vagal activity, which is restored upon re-perfusion with bulk lumenal contents or sterile filtrates from the small intestine and cecum of SPF, but not GF, mice. Of several candidates identified by metabolomic profiling, microbiome-dependent short-chain fatty acids, bile acids, and 3-indoxyl sulfate stimulate vagal activity with varied response kinetics, which is blocked by co-perfusion of pharmacological antagonists of FFAR2, TGR5, and TRPA1, respectively, into the small intestine. At the single-unit level, serial perfusion of each metabolite class elicits more singly responsive neurons than dually responsive neurons, suggesting distinct neuronal detection of different microbiome- and macronutrient-dependent metabolites. Finally, microbial metabolite-induced increases in vagal activity correspond with activation of neurons in the nucleus of the solitary tract, which is also blocked by co-administration of their respective receptor antagonists. Results from this study reveal that the gut microbiome regulates select metabolites in the intestinal lumen that differentially activate chemosensory vagal afferent neurons, thereby enabling microbial modulation of interoceptive signals for gut-brain communication. HIGHLIGHTS Microbiota colonization status modulates afferent vagal nerve activityGut microbes differentially regulate metabolites in the small intestine and cecumSelect microbial metabolites stimulate vagal afferents with varied response kineticsSelect microbial metabolites activate vagal afferent neurons and brainstem neurons via receptor-dependent signaling.
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19
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Strain MM, Conley NJ, Kauffman LS, Espinoza L, Fedorchak S, Martinez PC, Crook ME, Jalil M, Hodes GE, Abbott SBG, Güler AD, Campbell JN, Boychuk CR. Dorsal Motor Vagal Neurons Can Elicit Bradycardia and Reduce Anxiety-Like Behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.566855. [PMID: 38014247 PMCID: PMC10680764 DOI: 10.1101/2023.11.14.566855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Cardiovagal neurons (CVNs) innervate cardiac ganglia through the vagus nerve to control cardiac function. Although the cardioinhibitory role of CVNs in nucleus ambiguus (CVNNA) is well established, the nature and functionality of CVNs in dorsal motor nucleus of the vagus (CVNDMV) is less clear. We therefore aimed to characterize CVNDMV anatomically, physiologically, and functionally. Optogenetically activating cholinergic DMV neurons resulted in robust bradycardia through peripheral muscarinic (parasympathetic) and nicotinic (ganglionic) acetylcholine receptors, but not beta-1-adrenergic (sympathetic) receptors. Retrograde tracing from the cardiac fat pad labeled CVNNA and CVNDMV through the vagus nerve. Using whole cell patch clamp, CVNDMV demonstrated greater hyperexcitability and spontaneous action potential firing ex vivo despite similar resting membrane potentials, compared to CVNNA. Chemogenetically activating DMV also caused significant bradycardia with a correlated reduction in anxiety-like behavior. Thus, DMV contains uniquely hyperexcitable CVNs capable of cardioinhibition and robust anxiolysis.
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Affiliation(s)
- Misty M. Strain
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX
| | | | - Lily S. Kauffman
- Department of Biology, University of Virginia, Charlottesville, VA
| | - Liliana Espinoza
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX
| | - Stephanie Fedorchak
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX
| | | | - Maisie E. Crook
- Department of Biology, University of Virginia, Charlottesville, VA
| | - Maira Jalil
- Department of Biology, University of Virginia, Charlottesville, VA
| | - Georgia E. Hodes
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA
| | | | - Ali D. Güler
- Department of Biology, University of Virginia, Charlottesville, VA
| | - John N. Campbell
- Department of Biology, University of Virginia, Charlottesville, VA
| | - Carie R. Boychuk
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, San Antonio, TX
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO
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20
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Chen D, Hagen SJ, Boyce M, Zhao CM. Neuroendocrine mechanism of gastric acid secretion: Historical perspectives and recent developments in physiology and pharmacology. J Neuroendocrinol 2023; 35:e13305. [PMID: 37317882 PMCID: PMC10656367 DOI: 10.1111/jne.13305] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 04/24/2023] [Accepted: 05/10/2023] [Indexed: 06/16/2023]
Abstract
The physiology of gastric acid secretion is one of the earliest subjects in medical literature and has been continuously studied since 1833. Starting with the notion that neural stimulation alone drives acid secretion, progress in understanding the physiology and pathophysiology of this process has led to the development of therapeutic strategies for patients with acid-related diseases. For instance, understanding the physiology of parietal cells led to the developments of histamine 2 receptor blockers, proton pump inhibitors (PPIs), and recently, potassium-competitive acid blockers. Furthermore, understanding the physiology and pathophysiology of gastrin has led to the development of gastrin/CCK2 receptor (CCK2 R) antagonists. The need for refinement of existing drugs in patients have led to second and third generation drugs with better efficacy at blocking acid secretion. Further understanding of the mechanism of acid secretion by gene targeting in mice has enabled us to dissect the unique role for each regulator to leverage and justify the development of new targeted therapeutics for acid-related disorders. Further research on the mechanism of stimulation of gastric acid secretion and the physiological significances of gastric acidity in gut microbiome is needed in the future.
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Affiliation(s)
- Duan Chen
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Susan J Hagen
- Department of Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, USA
| | | | - Chun-Mei Zhao
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
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21
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Edwards PT, Soni KG, Conner ME, Fowler SW, Foong JPP, Stavely R, Cheng LS, Preidis GA. Site-specific pathophysiology in a neonatal mouse model of gastroparesis. Neurogastroenterol Motil 2023; 35:e14676. [PMID: 37772676 PMCID: PMC11023621 DOI: 10.1111/nmo.14676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 07/30/2023] [Accepted: 08/28/2023] [Indexed: 09/30/2023]
Abstract
BACKGROUND Early-life events impact maturation of the gut microbiome, enteric nervous system, and gastrointestinal motility. We examined three regions of gastric tissue to determine how maternal separation and gut microbes influence the structure and motor function of specific regions of the neonatal mouse stomach. METHODS Germ-free and conventionally housed C57BL/6J mouse pups underwent timed maternal separation (TmSep) or nursed uninterrupted (controls) until 14 days of life. We assessed gastric emptying by quantifying the progression of gavaged fluorescein isothiocyanate (FITC)-dextran. With isolated rings of forestomach, corpus, and antrum, we measured tone and contractility by force transduction, gastric wall thickness by light microscopy, and myenteric plexus neurochemistry by whole-mount immunostaining. KEY RESULTS Regional gastric sampling revealed site-specific differences in contractile patterns and myenteric plexus structure. In neonatal mice, TmSep prolonged gastric emptying. In the forestomach, TmSep increased contractile responses to carbachol, decreased muscularis externa and mucosa thickness, and increased the relative proportion of myenteric plexus nNOS+ neurons. Germ-free conditions did not appreciably alter the structure or function of the neonatal mouse stomach and did not impact the changes caused by TmSep. CONCLUSIONS AND INFERENCES A regional sampling approach facilitates site-specific investigations of murine gastric motor physiology and histology to identify site-specific alterations that may impact gastrointestinal function. Delayed gastric emptying in TmSep is associated with a thinner muscle wall, exaggerated cholinergic contractile responses, and increased proportions of inhibitory myenteric plexus nNOS+ neurons in the forestomach. Gut microbes do not profoundly affect the development of the neonatal mouse stomach or the gastric pathophysiology that results from TmSep.
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Affiliation(s)
- Price T. Edwards
- Division of Gastroenterology, Hepatology & Nutrition, Department of Pediatrics, Baylor College of Medicine and Texas Children’s Hospital, Houston, TX, USA
| | - Krishnakant G. Soni
- Division of Gastroenterology, Hepatology & Nutrition, Department of Pediatrics, Baylor College of Medicine and Texas Children’s Hospital, Houston, TX, USA
| | - Margaret E. Conner
- Molecular Virology and Microbiology, Department of Education, Innovation and Technology, Baylor College of Medicine, Houston, TX, USA
| | - Stephanie W. Fowler
- Molecular Virology and Microbiology, Department of Education, Innovation and Technology, Baylor College of Medicine, Houston, TX, USA
| | - Jaime P. P. Foong
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, Vic., Australia
| | - Rhian Stavely
- Department of Pediatric Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Lily S. Cheng
- Michael E. DeBakey Department of Surgery, Division of Pediatric Surgery, Texas Children’s Surgical Oncology Program, Baylor College of Medicine and Texas Children’s Hospital, Houston, TX, USA
| | - Geoffrey A. Preidis
- Division of Gastroenterology, Hepatology & Nutrition, Department of Pediatrics, Baylor College of Medicine and Texas Children’s Hospital, Houston, TX, USA
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22
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Grams KJ, Neumueller SE, Mouradian GC, Burgraff NJ, Hodges MR, Pan L, Forster HV. Mild and moderate chronic hypercapnia elicit distinct transcriptomic responses of immune function in cardiorespiratory nuclei. Physiol Genomics 2023; 55:487-503. [PMID: 37602394 PMCID: PMC11178267 DOI: 10.1152/physiolgenomics.00038.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 08/03/2023] [Accepted: 08/17/2023] [Indexed: 08/22/2023] Open
Abstract
Chronic hypercapnia (CH) is a hallmark of respiratory-related diseases, and the level of hypercapnia can acutely or progressively become more severe. Previously, we have shown time-dependent adaptations in steady-state physiology during mild (arterial Pco2 ∼55 mmHg) and moderate (∼60 mmHg) CH in adult goats, including transient (mild CH) or sustained (moderate CH) suppression of acute chemosensitivity suggesting limitations in adaptive respiratory control mechanisms as the level of CH increases. Changes in specific markers of glutamate receptor plasticity, interleukin-1ß, and serotonergic modulation within key nodes of cardiorespiratory control do not fully account for the physiological adaptations to CH. Here, we used an unbiased approach (bulk tissue RNA sequencing) to test the hypothesis that mild or moderate CH elicits distinct gene expression profiles in important brain stem regions of cardiorespiratory control, which may explain the contrasting responses to CH. Gene expression profiles from the brain regions validated the accuracy of tissue biopsy methodology. Differential gene expression analyses revealed greater effects of CH on brain stem sites compared with the medial prefrontal cortex. Mild CH elicited an upregulation of predominantly immune-related genes and predicted activation of immune-related pathways and functions. In contrast, moderate CH broadly led to downregulation of genes and predicted inactivation of cellular pathways related to the immune response and vascular function. These data suggest that mild CH leads to a steady-state activation of neuroinflammatory pathways within the brain stem, whereas moderate CH drives the opposite response. Transcriptional shifts in immune-related functions may underlie the cardiorespiratory network's capability to respond to acute, more severe hypercapnia when in a state of progressively increased CH.NEW & NOTEWORTHY Mild chronic hypercapnia (CH) broadly upregulated immune-related genes and a predicted activation of biological pathways related to immune cell activity and the overall immune response. In contrast, moderate CH primarily downregulated genes related to major histocompatibility complex signaling and vasculature function that led to a predicted inactivation of pathways involving the immune response and vascular endothelial function. The severity-dependent effect on immune responses suggests that neuroinflammation has an important role in CH and may be important in the maintenance of proper ventilatory responses to acute and chronic hypercapnia.
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Affiliation(s)
- Kirstyn J Grams
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Suzanne E Neumueller
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Gary C Mouradian
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Nicholas J Burgraff
- Center for Integrated Brain Research, Seattle Children's Research Institute, Seattle, Washington, United States
| | - Matthew R Hodges
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Lawrence Pan
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, United States
| | - Hubert V Forster
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States
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23
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Wang Y, Lai H, Zhang T, Wu J, Tang H, Liang X, Ren D, Huang J, Li W. Mitochondria of intestinal epithelial cells in depression: Are they at a crossroads of gut-brain communication? Neurosci Biobehav Rev 2023; 153:105403. [PMID: 37742989 DOI: 10.1016/j.neubiorev.2023.105403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/11/2023] [Accepted: 09/20/2023] [Indexed: 09/26/2023]
Abstract
The role of gut dysbiosis in depression is well established. However, recent studies have shown that gut microbiota is regulated by intestinal epithelial cell (IEC) mitochondria, which has yet to receive much attention. This review summarizes the recent developments about the critical role of IEC mitochondria in actively maintaining gut microbiota, intestinal metabolism, and immune homeostasis. We propose that IEC mitochondrial dysfunction alters gut microbiota composition, participates in cell fate, mediates oxidative stress, activates the peripheral immune system, causes peripheral inflammation, and transmits peripheral signals through the vagus and enteric nervous systems. These pathological alterations lead to brain inflammation, disruption of the blood-brain barrier, activation of the hypothalamic-pituitary-adrenal axis, activation of microglia and astrocytes, induction of neuronal loss, and ultimately depression. Furthermore, we highlight the prospect of treating depression through the mitochondria of IECs. These new findings suggest that the mitochondria of IECs may be a newly found important factor in the pathogenesis of depression and represent a potential new strategy for treating depression.
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Affiliation(s)
- Yi Wang
- Basic Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan Province 610000, PR China
| | - Han Lai
- School of Foreign Languages, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan Province 610000, PR China
| | - Tian Zhang
- Basic Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan Province 610000, PR China
| | - Jing Wu
- Basic Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan Province 610000, PR China
| | - Huiling Tang
- Basic Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan Province 610000, PR China
| | - Xuanwei Liang
- Basic Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan Province 610000, PR China
| | - Dandan Ren
- Basic Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan Province 610000, PR China
| | - Jinzhu Huang
- School of Nursing, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan Province 610000, PR China.
| | - Weihong Li
- Basic Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan Province 610000, PR China.
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Wang YY, Zhou YQ, Xie JX, Zhang X, Wang SC, Li Q, Hu LP, Jiang SH, Yi SQ, Xu J, Cao H, Zhao EH, Li J. MAOA suppresses the growth of gastric cancer by interacting with NDRG1 and regulating the Warburg effect through the PI3K/AKT/mTOR pathway. Cell Oncol (Dordr) 2023; 46:1429-1444. [PMID: 37249744 DOI: 10.1007/s13402-023-00821-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2023] [Indexed: 05/31/2023] Open
Abstract
OBJECTIVE Previous studies have indicated that neurotransmitters play important roles in the occurrence and development of gastric cancer. MAOA is an important catecholamine neurotransmitter-degrading enzyme involved in the degradation of norepinephrine, epinephrine and serotonin. To find a potential therapeutic target for the treatment of gastric cancer, the biological functions of MAOA and the underlying mechanism in gastric cancer need to be explored. METHODS The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) datasets, Kaplan‒Meier (KM) plotter were used to identify the differentially expressed genes, which mainly involved the degradation and synthesis enzymes of neurotransmitters in gastric cancer. We also investigated the expression pattern of MAOA in human and mouse tissues and cell lines by immunohistochemistry and Western blotting analysis. Western blotting, quantitative real-time PCR, enzyme-linked immunosorbent assay (ELISA) and a Seahorse experiment were used to identify the molecular mechanism of cancer cell glycolysis. MAOA expression and patient survival were analysed in the Ren Ji cohort, and univariate and multivariate analyses were performed based on the clinicopathological characteristics of the above samples. RESULTS MAOA expression was significantly downregulated in gastric cancer tissue and associated with poor patient prognosis. Moreover, the expression level of MAOA in gastric cancer tissue had a close negative correlation with the SUXmax value of PET-CT in patients. MAOA suppressed tumour growth and glycolysis and promoted cancer cell apoptosis. We also reported that MAOA can interact with NDRG1 and regulate glycolysis through suppression of the PI3K/Akt/mTOR pathway. MAOA expression may serve as an independent prognostic factor in gastric cancer patients. CONCLUSIONS MAOA attenuated glycolysis and inhibited the progression of gastric cancer through the PI3K/Akt/mTOR pathway. Loss of function or downregulation of MAOA can facilitate gastric cancer progression. Overexpression of MAOA and inhibition of the PI3K/Akt/mTOR pathway may provide a potential method for gastric cancer treatment in clinical therapeutic regimens.
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Affiliation(s)
- Yang-Yang Wang
- Department of Gastrointestinal Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Yao-Qi Zhou
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Jia-Xuan Xie
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Xiang Zhang
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Shu-Chang Wang
- Department of Gastrointestinal Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China
| | - Qing Li
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Li-Peng Hu
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Shu-Heng Jiang
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Shuang-Qin Yi
- Department of Frontier Health Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Hachioji, Japan
| | - Jia Xu
- Department of Gastrointestinal Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Hui Cao
- Department of Gastrointestinal Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - En-Hao Zhao
- Department of Gastrointestinal Surgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, 160 Pujian Road, Shanghai, 200127, China.
| | - Jun Li
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
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Li L, Yang J, Liu T, Shi Y. Role of the gut-microbiota-metabolite-brain axis in the pathogenesis of preterm brain injury. Biomed Pharmacother 2023; 165:115243. [PMID: 37517290 DOI: 10.1016/j.biopha.2023.115243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/09/2023] [Accepted: 07/25/2023] [Indexed: 08/01/2023] Open
Abstract
Brain injury, a common complication in preterm infants, includes the destruction of the key structural and functional connections of the brain and causes neurodevelopmental disorders; it has high morbidity and mortality rates. The exact mechanism underlying brain injury in preterm infants is unclear. Intestinal flora plays a vital role in brain development and the maturation of the immune system in infants; however, detailed understanding of the gut microbiota-metabolite-brain axis in preterm infants is lacking. In this review, we summarise the key mechanisms by which the intestinal microbiota contribute to neurodevelopment and brain injury in preterm infants, with special emphasis on the influence of microorganisms and their metabolites on the regulation of neurocognitive development and neurodevelopmental risks related to preterm birth, infection and neonatal necrotising enterocolitis (NEC). This review provides support for the development and application of novel therapeutic strategies, including probiotics, prebiotics, synbiotics, and faecal bacteria transplantation targeting at brain injury in preterm infants.
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Affiliation(s)
- Ling Li
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang 110004, China.
| | - Jiahui Yang
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang 110004, China.
| | - Tianjing Liu
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang 110004, China.
| | - Yongyan Shi
- Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang 110004, China.
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26
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Shaffer C, Barrett LF, Quigley KS. Signal processing in the vagus nerve: Hypotheses based on new genetic and anatomical evidence. Biol Psychol 2023; 182:108626. [PMID: 37419401 PMCID: PMC10563766 DOI: 10.1016/j.biopsycho.2023.108626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 06/25/2023] [Accepted: 07/03/2023] [Indexed: 07/09/2023]
Abstract
Each organism must regulate its internal state in a metabolically efficient way as it interacts in space and time with an ever-changing and only partly predictable world. Success in this endeavor is largely determined by the ongoing communication between brain and body, and the vagus nerve is a crucial structure in that dialogue. In this review, we introduce the novel hypothesis that the afferent vagus nerve is engaged in signal processing rather than just signal relay. New genetic and structural evidence of vagal afferent fiber anatomy motivates two hypotheses: (1) that sensory signals informing on the physiological state of the body compute both spatial and temporal viscerosensory features as they ascend the vagus nerve, following patterns found in other sensory architectures, such as the visual and olfactory systems; and (2) that ascending and descending signals modulate one another, calling into question the strict segregation of sensory and motor signals, respectively. Finally, we discuss several implications of our two hypotheses for understanding the role of viscerosensory signal processing in predictive energy regulation (i.e., allostasis) as well as the role of metabolic signals in memory and in disorders of prediction (e.g., mood disorders).
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Affiliation(s)
- Clare Shaffer
- Department of Psychology, College of Science, Northeastern University, Boston, MA, USA.
| | - Lisa Feldman Barrett
- Department of Psychology, College of Science, Northeastern University, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Karen S Quigley
- Department of Psychology, College of Science, Northeastern University, Boston, MA, USA.
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Yuan PQ, Li T, Million M, Larauche M, Atmani K, Bellier JP, Taché Y. New insight on the enteric cholinergic innervation of the pig colon by central and peripheral nervous systems: reduction by repeated loperamide administration. Front Neurosci 2023; 17:1204233. [PMID: 37650102 PMCID: PMC10463754 DOI: 10.3389/fnins.2023.1204233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 07/24/2023] [Indexed: 09/01/2023] Open
Abstract
Introduction The central and peripheral nervous systems provide cholinergic innervation in the colon. The ability to assess their neuroanatomical distinctions is still a challenge. The pig is regarded as a relevant translational model due to the close similarity of its enteric nervous system (ENS) with that of human. Opioid-induced constipation is one of the most common side effects of opioid therapy. Methods We developed an approach to differentiate the central and peripheral cholinergic innervation of the pig colon using double immunolabeling with a novel mouse anti-human peripheral type of choline acetyltransferase (hpChAT) antibody combined with a rabbit anti-common type of ChAT (cChAT) antibody, a reliable marker of cholinergic neurons in the central nervous system. We examined their spatial configurations in 3D images of the ENS generated from CLARITY-cleared colonic segments. The density was quantitated computationally using Imaris 9.7. We assessed changes in the distal colon induced by daily oral treatment for 4 weeks with the μ opioid receptor agonist, loperamide (0.4 or 3 mg/kg). Results The double labeling showed strong cChAT immunoreactive (ir) fibers in the cervical vagus nerve and neuronal somata and fibers in the ventral horn of the sacral (S2) cord while hpChAT immunoreactivity was visualized only in the ENS but not in the vagus or sacral neural structures indicating the selectivity of these two antibodies. In the colonic myenteric plexus, dense hpChAT-ir neurons and fibers and varicose cChAT-ir fibers surrounding hpChAT-ir neurons were simultaneously visualized in 3D. The density of cChAT-ir varicose fibers in the outer submucosal plexus of both males and females were higher in the transverse and distal colon than in the proximal colon and in the myenteric plexus compared to the outer submucosal plexus and there was no cChAT innervation in the inner submucosal plexus. The density of hpChAT in the ENS showed no segmental or plexus differences in both sexes. Loperamide at the highest dose significantly decreased the density hpChAT-ir fibers + somata in the myenteric plexus of the distal colon. Discussion These data showed the distinct density of central cholinergic innervation between myenteric and submucosal plexuses among colonic segments and the localization of cChAT-ir fibers around peripheral hpChAT neurons in 3D. The reduction of cholinergic myenteric innervation by chronic opiate treatment points to target altered prokinetic cholinergic pathway to counteract opiate constipation.
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Affiliation(s)
- Pu-Qing Yuan
- CURE/Digestive Diseases Research Center, Vatche and Tamar Manoukian Digestive Diseases Division, UCLA David Geffen School of Medicine, Los Angeles, CA, United States
- VA GLAHS, Los Angeles, CA, United States
| | - Tao Li
- CURE/Digestive Diseases Research Center, Vatche and Tamar Manoukian Digestive Diseases Division, UCLA David Geffen School of Medicine, Los Angeles, CA, United States
| | - Mulugeta Million
- CURE/Digestive Diseases Research Center, Vatche and Tamar Manoukian Digestive Diseases Division, UCLA David Geffen School of Medicine, Los Angeles, CA, United States
| | - Muriel Larauche
- CURE/Digestive Diseases Research Center, Vatche and Tamar Manoukian Digestive Diseases Division, UCLA David Geffen School of Medicine, Los Angeles, CA, United States
| | - Karim Atmani
- CURE/Digestive Diseases Research Center, Vatche and Tamar Manoukian Digestive Diseases Division, UCLA David Geffen School of Medicine, Los Angeles, CA, United States
| | - Jean-Pierre Bellier
- Department of Neurology, Brigham and Women’s Hospital, Boston, MA, United States
| | - Yvette Taché
- CURE/Digestive Diseases Research Center, Vatche and Tamar Manoukian Digestive Diseases Division, UCLA David Geffen School of Medicine, Los Angeles, CA, United States
- VA GLAHS, Los Angeles, CA, United States
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28
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Abstract
The cardiovascular system is hardwired to the brain via multilayered afferent and efferent polysynaptic axonal connections. Two major anatomically and functionally distinct though closely interacting subcircuits within the cardiovascular system have recently been defined: The artery-brain circuit and the heart-brain circuit. However, how the nervous system impacts cardiovascular disease progression remains poorly understood. Here, we review recent findings on the anatomy, structures, and inner workings of the lesser-known artery-brain circuit and the better-established heart-brain circuit. We explore the evidence that signals from arteries or the heart form a systemic and finely tuned cardiovascular brain circuit: afferent inputs originating in the arterial tree or the heart are conveyed to distinct sensory neurons in the brain. There, primary integration centers act as hubs that receive and integrate artery-brain circuit-derived and heart-brain circuit-derived signals and process them together with axonal connections and humoral cues from distant brain regions. To conclude the cardiovascular brain circuit, integration centers transmit the constantly modified signals to efferent neurons which transfer them back to the cardiovascular system. Importantly, primary integration centers are wired to and receive information from secondary brain centers that control a wide variety of brain traits encoded in engrams including immune memory, stress-regulating hormone release, pain, reward, emotions, and even motivated types of behavior. Finally, we explore the important possibility that brain effector neurons in the cardiovascular brain circuit network connect efferent signals to other peripheral organs including the immune system, the gut, the liver, and adipose tissue. The enormous recent progress vis-à-vis the cardiovascular brain circuit allows us to propose a novel neurobiology-centered cardiovascular disease hypothesis that we term the neuroimmune cardiovascular circuit hypothesis.
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Affiliation(s)
- Sarajo K Mohanta
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University (LMU), Munich, Germany (S.K.M., C.Y., C.W., A.J.R.H.)
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance (S.K.M., C.W., A.J.R.H.)
| | - Changjun Yin
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University (LMU), Munich, Germany (S.K.M., C.Y., C.W., A.J.R.H.)
- Institute of Precision Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China (C.Y.)
| | - Christian Weber
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University (LMU), Munich, Germany (S.K.M., C.Y., C.W., A.J.R.H.)
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance (S.K.M., C.W., A.J.R.H.)
| | - Cristina Godinho-Silva
- Champalimaud Research, Champalimaud Centre for the Unknown, Lisbon, Portugal (C.G.-S., H.V.-F.)
| | | | - Qian J Xu
- Department of Neuroscience, Department of Cellular and Molecular Physiology, Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT (Q.J.X., R.B.C.)
| | - Rui B Chang
- Department of Neuroscience, Department of Cellular and Molecular Physiology, Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT (Q.J.X., R.B.C.)
| | - Andreas J R Habenicht
- Institute for Cardiovascular Prevention, Ludwig-Maximilians-University (LMU), Munich, Germany (S.K.M., C.Y., C.W., A.J.R.H.)
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance (S.K.M., C.W., A.J.R.H.)
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29
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Strain MM, Espinoza L, Fedorchak S, Littlejohn EL, Andrade MA, Toney GM, Boychuk CR. Early central cardiovagal dysfunction after high fat diet in a murine model. Sci Rep 2023; 13:6550. [PMID: 37085567 PMCID: PMC10121716 DOI: 10.1038/s41598-023-32492-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 03/28/2023] [Indexed: 04/23/2023] Open
Abstract
High fat diet (HFD) promotes cardiovascular disease and blunted cardiac vagal regulation. Temporal onset of loss of cardiac vagal control and its underlying mechanism are presently unclear. We tested our hypothesis that reduced central vagal regulation occurs early after HFD and contributes to poor cardiac regulation using cardiovascular testing paired with pharmacology in mice, molecular biology, and a novel bi-transgenic mouse line. Results show HFD, compared to normal fat diet (NFD), significantly blunted cardio/pulmonary chemoreflex bradycardic responses after 15 days, extending as far as tested (> 30 days). HFD produced resting tachycardia by day 3, reflected significant loss of parasympathetic tone. No differences in bradycardic responses to graded electrical stimulation of the distal cut end of the cervical vagus indicated diet-induced differences in vagal activity were centrally mediated. In nucleus ambiguus (NA), surface expression of δ-subunit containing type A gamma-aminobutyric acid receptors (GABAA(δ)R) increased at day 15 of HFD. Novel mice lacking δ-subunit expression in vagal motor neurons (ChAT-δnull) failed to exhibit blunted reflex bradycardia or resting tachycardia after two weeks of HFD. Thus, reduced parasympathetic output contributes to early HFD-induced HR dysregulation, likely through increased GABAA(δ)Rs. Results underscore need for research on mechanisms of early onset increases in GABAA(δ)R expression and parasympathetic dysfunction after HFD.
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Affiliation(s)
- Misty M Strain
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Liliana Espinoza
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Stephanie Fedorchak
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Erica L Littlejohn
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Mary Ann Andrade
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Glenn M Toney
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA
| | - Carie R Boychuk
- Department of Cellular and Integrative Physiology, Long School of Medicine, University of Texas Health San Antonio, 7703 Floyd Curl Drive, Mail Code 7746, San Antonio, TX, 78229-3901, USA.
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30
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Jaffey DM, McAdams JL, Baronowsky EA, Black D, Powley TL. Vagal preganglionic axons arborize in the myenteric plexus into two types: nitrergic and non-nitrergic postganglionic motor pools? Am J Physiol Regul Integr Comp Physiol 2023; 324:R305-R316. [PMID: 36622086 PMCID: PMC9942884 DOI: 10.1152/ajpregu.00260.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/16/2022] [Accepted: 01/03/2023] [Indexed: 01/10/2023]
Abstract
Vagal preganglionic neurons innervate myenteric ganglia. These autonomic efferents are distributed so densely within the ganglia that it has been impractical to track individual vagal axons through the myenteric plexus with tracer labeling. To evaluate whether vagal efferent axons evidence selectivity, particularly for nitrergic or non-nitrergic myenteric neurons within the plexus, we limited the numbers and volumes of brainstem dextran biotin tracer injections per animal. Reduced labeling and the use of immunohistochemistry generated cases in which some individual axons could be distinguished and traced in three dimensions (Neurolucida) within and among successive (up to 46) myenteric ganglia. In the myenteric plexus of all stomach regions, the majority (∼86%) of vagal efferents were organized into two distinct subtypes. One subtype (∼24% of dextran-labeled efferents, designated "primarily nitrergic") selectively contacted and linked-both within and between ganglia-nitric oxide synthase positive (nNOS+) neurons into presumptive motor modules. A second subtype (∼62% of efferents, designated "primarily non-nitrergic") appeared to selectively contact and link-both within and between ganglia-non-nitrergic enteric neurons into a second type of effector ensemble. A third candidate type (∼14% of labeled preganglionics), appeared to lack "nitrergic selectivity" and to contact both nNOS+ and nNOS- enteric neurons. In addition to the quantitative assessment of the efferent axons in stomach, qualitative observations of the proximal duodenum indicated similar selective vagal efferent projections, in proportions comparable with those evaluated in the stomach. Limited injections of tracer, three-dimensional (3-D) tracing of individual axons, and histochemistry of myenteric neurons might distinguish additional efferent phenotypes.NEW & NOTEWORTHY The present study highlights the following: 1) one type of vagal efferent axon selectively innervates nitrergic upper gastrointestinal myenteric neurons; 2) a second type of vagal efferent selectively innervates non-nitrergic gastrointestinal myenteric neurons; and 3) the two types of vagal efferents might modulate peristalsis reciprocally and cooperatively.
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Affiliation(s)
- D M Jaffey
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - J L McAdams
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - E A Baronowsky
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - D Black
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - T L Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
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31
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Li X, Wang L. Rethinking the visceral innervation --- Peek into the emerging field of molecular dissection of neural signals. Biochem Biophys Res Commun 2022; 633:20-22. [DOI: 10.1016/j.bbrc.2022.09.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 09/02/2022] [Indexed: 11/06/2022]
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32
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Neuhuber WL, Berthoud HR. Functional anatomy of the vagus system: How does the polyvagal theory comply? Biol Psychol 2022; 174:108425. [PMID: 36100134 DOI: 10.1016/j.biopsycho.2022.108425] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/07/2022] [Accepted: 09/07/2022] [Indexed: 11/16/2022]
Abstract
Due to its pivotal role in autonomic networks and interoception, the vagus attracts continued interest from both basic scientists and therapists of various clinical disciplines. In particular, the widespread use of heart rate variability as an index of autonomic cardiac control and a proposed central role of the vagus in biopsychological concepts, e.g., the polyvagal theory, provide a good opportunity to recall basic features of vagal anatomy. In addition to the "classical" vagal brainstem nuclei, i.e., dorsal motor nucleus, nucleus ambiguus and nucleus tractus solitarii, the spinal trigeminal and paratrigeminal nuclei come into play as targets of vagal afferents. On the other hand, the nucleus of the solitary tract receives and integrates not only visceral but also somatic afferents.
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Affiliation(s)
- Winfried L Neuhuber
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität, Krankenhausstrasse 9, Erlangen, Germany.
| | - Hans-Rudolf Berthoud
- Neurobiology of Nutrition & Metabolism Department, Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808, USA.
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33
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Blum JA, Gitler AD. Singling out motor neurons in the age of single-cell transcriptomics. Trends Genet 2022; 38:904-919. [PMID: 35487823 PMCID: PMC9378604 DOI: 10.1016/j.tig.2022.03.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/24/2022] [Accepted: 03/28/2022] [Indexed: 01/07/2023]
Abstract
Motor neurons are a remarkably powerful cell type in the central nervous system. They innervate and control the contraction of virtually every muscle in the body and their dysfunction underlies numerous neuromuscular diseases. Some motor neurons seem resistant to degeneration whereas others are vulnerable. The intrinsic heterogeneity of motor neurons in adult organisms has remained elusive. The development of high-throughput single-cell transcriptomics has changed the paradigm, empowering rapid isolation and profiling of motor neuron nuclei, revealing remarkable transcriptional diversity within the skeletal and autonomic nervous systems. Here, we discuss emerging technologies for defining motor neuron heterogeneity in the adult motor system as well as implications for disease and spinal cord injury. We establish a roadmap for future applications of emerging techniques - such as epigenetic profiling, spatial RNA sequencing, and single-cell somatic mutational profiling to adult motor neurons, which will revolutionize our understanding of the healthy and degenerating adult motor system.
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Affiliation(s)
- Jacob A Blum
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA; Neurosciences Interdepartmental Program, Stanford University School of Medicine, Stanford, CA, USA.
| | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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34
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Cheng W, Gordian D, Ludwig MQ, Pers TH, Seeley RJ, Myers MG. Hindbrain circuits in the control of eating behaviour and energy balance. Nat Metab 2022; 4:826-835. [PMID: 35879458 DOI: 10.1038/s42255-022-00606-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/13/2022] [Indexed: 01/15/2023]
Abstract
Body weight and adiposity represent biologically controlled parameters that are influenced by a combination of genetic, developmental and environmental variables. Although the hypothalamus plays a crucial role in matching caloric intake with energy expenditure to achieve a stable body weight, it is now recognized that neuronal circuits in the hindbrain not only serve to produce nausea and to terminate feeding in response to food consumption or during pathological states, but also contribute to the long-term control of body weight. Additionally, recent work has identified hindbrain neurons that are capable of suppressing food intake without producing aversive responses like those associated with nausea. Here we review recent advances in our understanding of the hindbrain neurons that control feeding, particularly those located in the area postrema and the nucleus tractus solitarius. We frame this information in the context of new atlases of hindbrain neuronal populations and develop a model of the hindbrain circuits that control food intake and energy balance, suggesting important areas for additional research.
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Affiliation(s)
- Wenwen Cheng
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Desiree Gordian
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, USA
| | - Mette Q Ludwig
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Tune H Pers
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Randy J Seeley
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Martin G Myers
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.
- Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, USA.
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
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35
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Ma Q. Somatotopic organization of autonomic reflexes by acupuncture. Curr Opin Neurobiol 2022; 76:102602. [PMID: 35780689 DOI: 10.1016/j.conb.2022.102602] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 12/18/2022]
Abstract
Acupuncture has been practiced for more than 2000 years in China and now all over the world. One core idea behind this medical practice is that stimulation at specific body regions (acupoints) can distantly modulate organ physiology, but the underlying scientific basis has been long debated. Here, I summarize evidence supporting that long-distant acupuncture effects operate partly through somato-autonomic reflexes, leading to activation of sympathetic and/or parasympathetic pathways. I then discuss how the patterning of the somatosensory system along the rostro-caudal axis and the cutaneous-deep tissue axis might explain acupoint specificity and selectivity in driving specific autonomic pathways, particularly those modulating gastrointestinal motility and systemic inflammation.
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Affiliation(s)
- Qiufu Ma
- Dana-Farber Cancer Institute and Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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36
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Coverdell TC, Abraham-Fan RJ, Wu C, Abbott SBG, Campbell JN. Genetic encoding of an esophageal motor circuit. Cell Rep 2022; 39:110962. [PMID: 35705034 PMCID: PMC9255432 DOI: 10.1016/j.celrep.2022.110962] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 03/24/2022] [Accepted: 05/24/2022] [Indexed: 12/02/2022] Open
Abstract
Motor control of the striated esophagus originates in the nucleus ambiguus (nAmb), a vagal motor nucleus that also contains upper airway motor neurons and parasympathetic preganglionic neurons for the heart and lungs. We disambiguate nAmb neurons based on their genome-wide expression profiles, efferent circuitry, and ability to control esophageal muscles. Our single-cell RNA sequencing analysis predicts three molecularly distinct nAmb neuron subtypes and annotates them by subtype-specific marker genes: Crhr2, Vipr2, and Adcyap1. Mapping the axon projections of the nAmb neuron subtypes reveals that Crhr2nAmb neurons innervate the esophagus, raising the possibility that they control esophageal muscle function. Accordingly, focal optogenetic stimulation of cholinergic Crhr2+ fibers in the esophagus results in contractions. Activating Crhr2nAmb neurons has no effect on heart rate, a key parasympathetic function of the nAmb, whereas activating all of the nAmb neurons robustly suppresses heart rate. Together, these results reveal a genetically defined circuit for motor control of the esophagus. Primary motor neurons for the esophagus reside in the nucleus ambiguus (nAmb) of the hindbrain, but little is known about their molecular identity. Coverdell et al. find that the nAmb comprises three molecularly and anatomically distinct neuron subtypes, one of which selectively innervates and can contract esophageal muscle.
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Affiliation(s)
- Tatiana C Coverdell
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA 22903, USA; Department of Biology, University of Virginia, Charlottesville, VA 22903, USA; Department of Pharmacology, University of Virginia, Charlottesville, VA 22903, USA
| | | | - Chen Wu
- Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Stephen B G Abbott
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22903, USA
| | - John N Campbell
- Department of Biology, University of Virginia, Charlottesville, VA 22903, USA.
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37
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Veerakumar A, Yung AR, Liu Y, Krasnow MA. Molecularly defined circuits for cardiovascular and cardiopulmonary control. Nature 2022; 606:739-746. [PMID: 35650438 PMCID: PMC9297035 DOI: 10.1038/s41586-022-04760-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 04/13/2022] [Indexed: 01/29/2023]
Abstract
The sympathetic and parasympathetic nervous systems powerfully regulate internal organs1, but the molecular and functional diversity of their constituent neurons and circuits remains largely unknown. Here we use retrograde neuronal tracing, single-cell RNA sequencing, optogenetics, and physiological experiments to dissect the cardiac parasympathetic control circuit in mice. We show that cardiac-innervating neurons in the brainstem nucleus ambiguus (Amb) are comprised of two molecularly, anatomically, and functionally distinct subtypes. One we call ACV (ambiguus cardiovascular) neurons (~35 neurons per Amb), define the classical cardiac parasympathetic circuit. They selectively innervate a subset of cardiac parasympathetic ganglion neurons and mediate the baroreceptor reflex, slowing heart rate and atrioventricular node conduction in response to increased blood pressure. The other, ACP (ambiguus cardiopulmonary) neurons (~15 neurons per Amb) innervate cardiac ganglion neurons intermingled with and functionally indistinguishable from those innervated by ACV neurons, but surprisingly also innervate most or all lung parasympathetic ganglion neurons; clonal labeling shows individual ACP neurons innervate both organs. ACP neurons mediate the dive reflex, the simultaneous bradycardia and bronchoconstriction that follows water immersion. Thus, parasympathetic control of the heart is organized into two parallel circuits, one that selectively controls cardiac function (ACV circuit) and another that coordinates cardiac and pulmonary function (ACP circuit). This new understanding of cardiac control has implications for treating cardiac and pulmonary diseases and for elucidating the control and coordination circuits of other organs.
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Affiliation(s)
- Avin Veerakumar
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA.,Department of Bioengineering, Stanford University, Stanford, CA, USA.,Medical Scientist Training Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Andrea R Yung
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Yin Liu
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Mark A Krasnow
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA.
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38
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Prescott SL, Liberles SD. Internal senses of the vagus nerve. Neuron 2022; 110:579-599. [PMID: 35051375 PMCID: PMC8857038 DOI: 10.1016/j.neuron.2021.12.020] [Citation(s) in RCA: 69] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/30/2021] [Accepted: 12/11/2021] [Indexed: 12/16/2022]
Abstract
The vagus nerve is an indispensable body-brain connection that controls vital aspects of autonomic physiology like breathing, heart rate, blood pressure, and gut motility, reflexes like coughing and swallowing, and survival behaviors like feeding, drinking, and sickness responses. Classical physiological studies and recent molecular/genetic approaches have revealed a tremendous diversity of vagal sensory neuron types that innervate different internal organs, with many cell types remaining poorly understood. Here, we review the state of knowledge related to vagal sensory neurons that innervate the respiratory, cardiovascular, and digestive systems. We focus on cell types and their response properties, physiological/behavioral roles, engaged neural circuits and, when possible, sensory receptors. We are only beginning to understand the signal transduction mechanisms used by vagal sensory neurons and upstream sentinel cells, and future studies are needed to advance the field of interoception to the level of mechanistic understanding previously achieved for our external senses.
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39
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Chang L, Wei Y, Hashimoto K. Brain Research Bulletin: Special Issue: Brain–body communication in health and diseases, Brain–gut–microbiota axis in depression: A historical overview and future directions. Brain Res Bull 2022; 182:44-56. [DOI: 10.1016/j.brainresbull.2022.02.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/03/2022] [Accepted: 02/04/2022] [Indexed: 12/14/2022]
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40
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Neural signalling of gut mechanosensation in ingestive and digestive processes. Nat Rev Neurosci 2022; 23:135-156. [PMID: 34983992 DOI: 10.1038/s41583-021-00544-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2021] [Indexed: 12/29/2022]
Abstract
Eating and drinking generate sequential mechanosensory signals along the digestive tract. These signals are communicated to the brain for the timely initiation and regulation of diverse ingestive and digestive processes - ranging from appetite control and tactile perception to gut motility, digestive fluid secretion and defecation - that are vital for the proper intake, breakdown and absorption of nutrients and water. Gut mechanosensation has been investigated for over a century as a common pillar of energy, fluid and gastrointestinal homeostasis, and recent discoveries of specific mechanoreceptors, contributing ion channels and the well-defined circuits underlying gut mechanosensation signalling and function have further expanded our understanding of ingestive and digestive processes at the molecular and cellular levels. In this Review, we discuss our current understanding of the generation of mechanosensory signals from the digestive periphery, the neural afferent pathways that relay these signals to the brain and the neural circuit mechanisms that control ingestive and digestive processes, focusing on the four major digestive tract parts: the oral and pharyngeal cavities, oesophagus, stomach and intestines. We also discuss the clinical implications of gut mechanosensation in ingestive and digestive disorders.
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41
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Powley TL. Brain-gut communication: vagovagal reflexes interconnect the two "brains". Am J Physiol Gastrointest Liver Physiol 2021; 321:G576-G587. [PMID: 34643086 PMCID: PMC8616589 DOI: 10.1152/ajpgi.00214.2021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 01/31/2023]
Abstract
The gastrointestinal tract has its own "brain," the enteric nervous system or ENS, that executes routine housekeeping functions of digestion. The dorsal vagal complex in the central nervous system (CNS) brainstem, however, organizes vagovagal reflexes and establishes interconnections between the entire neuroaxis of the CNS and the gut. Thus, the dorsal vagal complex links the "CNS brain" to the "ENS brain." This brain-gut connectome provides reflex adjustments that optimize digestion and assimilation of nutrients and fluid. Vagovagal circuitry also generates the plasticity and adaptability needed to maintain homeostasis to coordinate among organs and to react to environmental situations. Arguably, this dynamic flexibility provided by the vagal circuitry may, in some circumstances, lead to or complicate maladaptive disorders.
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Affiliation(s)
- Terry L Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
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