1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Wang RL, Chang RB. The Coding Logic of Interoception. Annu Rev Physiol 2024; 86:301-327. [PMID: 38061018 PMCID: PMC11103614 DOI: 10.1146/annurev-physiol-042222-023455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2024]
Abstract
Interoception, the ability to precisely and timely sense internal body signals, is critical for life. The interoceptive system monitors a large variety of mechanical, chemical, hormonal, and pathological cues using specialized organ cells, organ innervating neurons, and brain sensory neurons. It is important for maintaining body homeostasis, providing motivational drives, and regulating autonomic, cognitive, and behavioral functions. However, compared to external sensory systems, our knowledge about how diverse body signals are coded at a system level is quite limited. In this review, we focus on the unique features of interoceptive signals and the organization of the interoceptive system, with the goal of better understanding the coding logic of interoception.
Collapse
Affiliation(s)
- Ruiqi L Wang
- Department of Neuroscience and Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA;
| | - Rui B Chang
- Department of Neuroscience and Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA;
| |
Collapse
|
3
|
Mudaliar SB, Poojary SS, Bharath Prasad AS, Mazumder N. Probiotics and Paraprobiotics: Effects on Microbiota-Gut-Brain Axis and Their Consequent Potential in Neuropsychiatric Therapy. Probiotics Antimicrob Proteins 2024:10.1007/s12602-024-10214-6. [PMID: 38294675 DOI: 10.1007/s12602-024-10214-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2024] [Indexed: 02/01/2024]
Abstract
Neuropsychiatric disorders are clinical conditions that affect cognitive function and emotional stability, often resulting from damage or disease in the central nervous system (CNS). These disorders are a worldwide concern, impacting approximately 12.5% of the global population. The gut microbiota has been linked to neurological development and function, implicating its involvement in neuropsychiatric conditions. Due to their interaction with gut microbial communities, probiotics offer a natural alternative to traditional treatments such as therapeutic drugs and interventions for alleviating neuropsychiatric symptoms. Introduced by Metchnikoff in the early 1900s, probiotics are live microorganisms that provide various health benefits, including improved digestion, enhanced sleep quality, and reduced mental problems. However, concerns about their safety, particularly in immunocompromised patients, warrant further investigation; this has led to the concept of "paraprobiotics", inactivated forms of beneficial microorganisms that offer a safer alternative. This review begins by exploring different methods of inactivation, each targeting specific cellular components like DNA or proteins. The choice of inactivation method is crucial, as the health benefits may vary depending on the conditions employed for inactivation. The subsequent sections focus on the potential mechanisms of action and specific applications of probiotics and paraprobiotics in neuropsychiatric therapy. Probiotics and paraprobiotics interact with gut microbes, modulating the gut microbial composition and alleviating gut dysbiosis. The resulting neuropsychiatric benefits primarily stem from the gut-brain axis, a bidirectional communication channel involving various pathways discussed in the review. While further research is needed, probiotics and paraprobiotics are promising therapeutic agents for the management of neuropsychiatric disorders.
Collapse
Affiliation(s)
- Samriti Balaji Mudaliar
- Department of Public Health & Genomics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Sumith Sundara Poojary
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Alevoor Srinivas Bharath Prasad
- Department of Public Health & Genomics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
| | - Nirmal Mazumder
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
| |
Collapse
|
4
|
Sanders KM, Drumm BT, Cobine CA, Baker SA. Ca 2+ dynamics in interstitial cells: foundational mechanisms for the motor patterns in the gastrointestinal tract. Physiol Rev 2024; 104:329-398. [PMID: 37561138 DOI: 10.1152/physrev.00036.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 06/29/2023] [Accepted: 08/06/2023] [Indexed: 08/11/2023] Open
Abstract
The gastrointestinal (GI) tract displays multiple motor patterns that move nutrients and wastes through the body. Smooth muscle cells (SMCs) provide the forces necessary for GI motility, but interstitial cells, electrically coupled to SMCs, tune SMC excitability, transduce inputs from enteric motor neurons, and generate pacemaker activity that underlies major motor patterns, such as peristalsis and segmentation. The interstitial cells regulating SMCs are interstitial cells of Cajal (ICC) and PDGF receptor (PDGFR)α+ cells. Together these cells form the SIP syncytium. ICC and PDGFRα+ cells express signature Ca2+-dependent conductances: ICC express Ca2+-activated Cl- channels, encoded by Ano1, that generate inward current, and PDGFRα+ cells express Ca2+-activated K+ channels, encoded by Kcnn3, that generate outward current. The open probabilities of interstitial cell conductances are controlled by Ca2+ release from the endoplasmic reticulum. The resulting Ca2+ transients occur spontaneously in a stochastic manner. Ca2+ transients in ICC induce spontaneous transient inward currents and spontaneous transient depolarizations (STDs). Neurotransmission increases or decreases Ca2+ transients, and the resulting depolarizing or hyperpolarizing responses conduct to other cells in the SIP syncytium. In pacemaker ICC, STDs activate voltage-dependent Ca2+ influx, which initiates a cluster of Ca2+ transients and sustains activation of ANO1 channels and depolarization during slow waves. Regulation of GI motility has traditionally been described as neurogenic and myogenic. Recent advances in understanding Ca2+ handling mechanisms in interstitial cells and how these mechanisms influence motor patterns of the GI tract suggest that the term "myogenic" should be replaced by the term "SIPgenic," as this review discusses.
Collapse
Affiliation(s)
- Kenton M Sanders
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada-Reno, Reno, Nevada, United States
| | - Bernard T Drumm
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Caroline A Cobine
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Salah A Baker
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada-Reno, Reno, Nevada, United States
| |
Collapse
|
5
|
Ma J, Nguyen D, Madas J, Bizanti A, Mistareehi A, Kwiat AM, Chen J, Lin M, Christie R, Hunter P, Heal M, Baldwin S, Tappan S, Furness JB, Powley TL, Cheng Z(J. Organization and morphology of calcitonin gene-related peptide-immunoreactive axons in the whole mouse stomach. J Comp Neurol 2023; 531:1608-1632. [PMID: 37694767 PMCID: PMC10593087 DOI: 10.1002/cne.25519] [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: 10/11/2022] [Revised: 05/19/2023] [Accepted: 05/29/2023] [Indexed: 09/12/2023]
Abstract
Nociceptive afferent axons innervate the stomach and send signals to the brain and spinal cord. Peripheral nociceptive afferents can be detected with a variety of markers (e.g., substance P [SP] and calcitonin gene-related peptide [CGRP]). We recently examined the topographical organization and morphology of SP-immunoreactive (SP-IR) axons in the whole mouse stomach muscular layer. However, the distribution and morphological structure of CGRP-IR axons remain unclear. We used immunohistochemistry labeling and applied a combination of imaging techniques, including confocal and Zeiss Imager M2 microscopy, Neurolucida 360 tracing, and integration of axon tracing data into a 3D stomach scaffold to characterize CGRP-IR axons and terminals in the whole mouse stomach muscular layers. We found that: (1) CGRP-IR axons formed extensive terminal networks in both ventral and dorsal stomachs. (2) CGRP-IR axons densely innervated the blood vessels. (3) CGRP-IR axons ran in parallel with the longitudinal and circular muscles. Some axons ran at angles through the muscular layers. (4) They also formed varicose terminal contacts with individual myenteric ganglion neurons. (5) CGRP-IR occurred in DiI-labeled gastric-projecting neurons in the dorsal root and vagal nodose ganglia, indicating CGRP-IR axons were visceral afferent axons. (6) CGRP-IR axons did not colocalize with tyrosine hydroxylase or vesicular acetylcholine transporter axons in the stomach, indicating CGRP-IR axons were not visceral efferent axons. (7) CGRP-IR axons were traced and integrated into a 3D stomach scaffold. For the first time, we provided a topographical distribution map of CGRP-IR axon innervation of the whole stomach muscular layers at the cellular/axonal/varicosity scale.
Collapse
Affiliation(s)
- Jichao Ma
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Duyen Nguyen
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Jazune Madas
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Ariege Bizanti
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Anas Mistareehi
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Andrew M. Kwiat
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Jin Chen
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Mabelle Lin
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Richard Christie
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Peter Hunter
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Maci Heal
- MBF Bioscience, Williston, Vermont, USA
| | | | | | - John B. Furness
- Department of Anatomy & Physiology, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Terry L. Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Zixi (Jack) Cheng
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| |
Collapse
|
6
|
Ma J, Nguyen D, Madas J, Kwiat AM, Toledo Z, Bizanti A, Kogut N, Mistareehi A, Bendowski K, Zhang Y, Chen J, Li DP, Powley TL, Furness JB, Cheng Z. Spinal afferent innervation in flat-mounts of the rat stomach: anterograde tracing. Sci Rep 2023; 13:17675. [PMID: 37853008 PMCID: PMC10584867 DOI: 10.1038/s41598-023-43120-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 09/20/2023] [Indexed: 10/20/2023] Open
Abstract
The dorsal root ganglia (DRG) project spinal afferent axons to the stomach. However, the distribution and morphology of spinal afferent axons in the stomach have not been well characterized. In this study, we used a combination of state-of-the-art techniques, including anterograde tracer injection into the left DRG T7-T11, avidin-biotin and Cuprolinic Blue labeling, Zeiss M2 Imager, and Neurolucida to characterize spinal afferent axons in flat-mounts of the whole rat stomach muscular wall. We found that spinal afferent axons innervated all regions with a variety of distinct terminal structures innervating different gastric targets: (1) The ganglionic type: some axons formed varicose contacts with individual neurons within myenteric ganglia. (2) The muscle type: most axons ran in parallel with the longitudinal and circular muscles and expressed spherical varicosities. Complex terminal structures were observed within the circular muscle layer. (3) The ganglia-muscle mixed type: some individual varicose axons innervated both myenteric neurons and the circular muscle, exhibiting polymorphic terminal structures. (4) The vascular type: individual varicose axons ran along the blood vessels and occasionally traversed the vessel wall. This work provides a foundation for future topographical anatomical and functional mapping of spinal afferent axon innervation of the stomach under normal and pathophysiological conditions.
Collapse
Affiliation(s)
- Jichao Ma
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA
| | - Duyen Nguyen
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA
| | - Jazune Madas
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA
| | - Andrew M Kwiat
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA
| | - Zulema Toledo
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA
| | - Ariege Bizanti
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA
| | - Nicole Kogut
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA
| | - Anas Mistareehi
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA
| | - Kohlton Bendowski
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA
| | - Yuanyuan Zhang
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA
| | - Jin Chen
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA
| | - De-Pei Li
- Department of Medicine, Center for Precision Medicine, School of Medicine, University of Missouri, Columbia, MO, 65212, USA
| | - Terry L Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, 479062, USA
| | - John B Furness
- Department of Anatomy and Physiology, University of Melbourne, and Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | - Zixi Cheng
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL, 32816, USA.
| |
Collapse
|
7
|
Page AJ. Plasticity of gastrointestinal vagal afferents in terms of feeding-related physiology and pathophysiology. J Physiol 2023. [PMID: 37737742 DOI: 10.1113/jp284075] [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: 06/09/2023] [Accepted: 09/07/2023] [Indexed: 09/23/2023] Open
Abstract
Gastrointestinal vagal afferents play an important role in communicating food related information from the gut to the brain. This information initiates vago-vagal reflexes essential for gut functions, including gut motility and secretions. These afferents also play a role in energy homeostasis, signalling the arrival, amount and nutrient composition of a meal to the central nervous system where it is processed ultimately leading to termination of a meal. Vagal afferent responses to food related stimuli demonstrate a high degree of plasticity, responding to short term changes in nutritional demand, such as the fluctuations that occur across a 24-hr or in response to a fast, as well as long term changes in energy demand, such as occurs during pregnancy. This plasticity is disrupted in disease states, such as obesity or chronic stress where there is hypo- and hypersensitivity of these afferents, respectively. Improved understanding of the plasticity of these afferents will enable identification of new treatment options for diseases associated with vagal afferent function.
Collapse
Affiliation(s)
- Amanda J Page
- Vagal Afferent Research Group, School of Biomedicine, University of Adelaide, Adelaide, South Australia, Australia
- Nutrition, Diabetes & Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institute, SAHMRI, Adelaide, South Australia, Australia
| |
Collapse
|
8
|
Frick LD, Hankir MK, Borner T, Malagola E, File B, Gero D. Novel Insights into the Physiology of Nutrient Sensing and Gut-Brain Communication in Surgical and Experimental Obesity Therapy. Obes Surg 2023; 33:2906-2916. [PMID: 37474864 PMCID: PMC10435392 DOI: 10.1007/s11695-023-06739-4] [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: 05/10/2023] [Revised: 07/05/2023] [Accepted: 07/14/2023] [Indexed: 07/22/2023]
Abstract
Despite standardized surgical technique and peri-operative care, metabolic outcomes of bariatric surgery are not uniform. Adaptive changes in brain function may play a crucial role in achieving optimal postbariatric weight loss. This review follows the anatomic-physiologic structure of the postbariatric nutrient-gut-brain communication chain through its key stations and provides a concise summary of recent findings in bariatric physiology, with a special focus on the composition of the intestinal milieu, intestinal nutrient sensing, vagal nerve-mediated gastrointestinal satiation signals, circulating hormones and nutrients, as well as descending neural signals from the forebrain. The results of interventional studies using brain or vagal nerve stimulation to induce weight loss are also summarized. Ultimately, suggestions are made for future diagnostic and therapeutic research for the treatment of obesity.
Collapse
Affiliation(s)
- Lukas D Frick
- Institute of Neuropathology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Mohammed K Hankir
- Department of Experimental Surgery, University Hospital Würzburg, Würzburg, Germany
| | - Tito Borner
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ermanno Malagola
- Division of Digestive and Liver Diseases, Department of Medicine and Irving Cancer Research Center, Columbia University Medical Center, New York, NY, 10032, USA
| | - Bálint File
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
- Wigner Research Centre for Physics, Budapest, Hungary
| | - Daniel Gero
- Department of Surgery and Transplantation, University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091, Zürich, Switzerland.
| |
Collapse
|
9
|
Ma J, Nguyen D, Madas J, Bizanti A, Mistareehi A, Kwiat AM, Chen J, Lin M, Christie R, Hunter P, Heal M, Baldwin S, Tappan S, Furness JB, Powley TL, Cheng ZJ. Mapping the Organization and Morphology of Calcitonin Gene-Related Peptide (CGRP)-IR Axons in the Whole Mouse Stomach. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.23.541811. [PMID: 37398245 PMCID: PMC10312482 DOI: 10.1101/2023.05.23.541811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Nociceptive afferent axons innervate the stomach and send signals to the brain and spinal cord. Peripheral nociceptive afferents can be detected with a variety of markers [e.g., substance P (SP) and calcitonin gene-related peptide (CGRP)]. We recently examined the topographical organization and morphology of SP-immunoreactive (SP-IR) axons in the whole mouse stomach muscular layer. However, the distribution and morphological structure of CGRP-IR axons remain unclear. We used immunohistochemistry labeling and applied a combination of imaging techniques, including confocal and Zeiss Imager M2 microscopy, Neurolucida 360 tracing, and integration of axon tracing data into a 3D stomach scaffold to characterize CGRP-IR axons and terminals in the whole mouse stomach muscular layers. We found that: 1) CGRP-IR axons formed extensive terminal networks in both ventral and dorsal stomachs. 2) CGRP-IR axons densely innervated the blood vessels. 3) CGRP-IR axons ran in parallel with the longitudinal and circular muscles. Some axons ran at angles through the muscular layers. 4) They also formed varicose terminal contacts with individual myenteric ganglion neurons. 5) CGRP-IR occurred in DiI-labeled gastric-projecting neurons in the dorsal root and vagal nodose ganglia, indicating CGRP-IR axons were visceral afferent axons. 6) CGRP-IR axons did not colocalize with tyrosine hydroxylase (TH) or vesicular acetylcholine transporter (VAChT) axons in the stomach, indicating CGRP-IR axons were not visceral efferent axons. 7) CGRP-IR axons were traced and integrated into a 3D stomach scaffold. For the first time, we provided a topographical distribution map of CGRP-IR axon innervation of the whole stomach muscular layers at the cellular/axonal/varicosity scale.
Collapse
|
10
|
Bizanti A, Zhang Y, Harden SW, Chen J, Hoover DB, Gozal D, Shivkumar K, Cheng ZJ. Catecholaminergic axon innervation and morphology in flat-mounts of atria and ventricles of mice. J Comp Neurol 2023; 531:596-617. [PMID: 36591925 PMCID: PMC10499115 DOI: 10.1002/cne.25444] [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: 09/03/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 01/03/2023]
Abstract
Sympathetic efferent axons regulate cardiac functions. However, the topographical distribution and morphology of cardiac sympathetic efferent axons remain insufficiently characterized due to the technical challenges involved in immunohistochemical labeling of the thick walls of the whole heart. In this study, flat-mounts of the left and right atria and ventricles of FVB mice were immunolabeled for tyrosine hydroxylase (TH), a marker of sympathetic nerves. Atrial and ventricular flat-mounts were scanned using a confocal microscope to construct montages. We found (1) In the atria: A few large TH-immunoreactive (IR) axon bundles entered both atria, branched into small bundles and then single axons that eventually formed very dense terminal networks in the epicardium, myocardium and inlet regions of great vessels to the atria. Varicose TH-IR axons formed close contact with cardiomyocytes, vessels, and adipocytes. Multiple intrinsic cardiac ganglia (ICG) were identified in the epicardium of both atria, and a subpopulation of the neurons in the ICG were TH-IR. Most TH-IR axons in bundles traveled through ICG before forming dense varicose terminal networks in cardiomyocytes. We did not observe varicose TH-IR terminals encircling ICG neurons. (2) In the left and right ventricles and interventricular septum: TH-IR axons formed dense terminal networks in the epicardium, myocardium, and vasculature. Collectively, TH labeling is achievable in flat-mounts of thick cardiac walls, enabling detailed mapping of catecholaminergic axons and terminal structures in the whole heart at single-cell/axon/varicosity scale. This approach provides a foundation for future quantification of the topographical organization of the cardiac sympathetic innervation in different pathological conditions.
Collapse
Affiliation(s)
- Ariege Bizanti
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Yuanyuan Zhang
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Scott W Harden
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Jin Chen
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Donald B Hoover
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee, USA
| | - David Gozal
- Department of Child Health and Child Health Research Institute, and Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, USA
| | - Kalyanam Shivkumar
- Department of Medicine, Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California, Los Angeles, California, USA
| | - Zixi Jack Cheng
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| |
Collapse
|
11
|
Kobashi M, Shimatani Y, Fujita M. Oxytocin increased intragastric pressure in the forestomach of rats via the dorsal vagal complex. Physiol Behav 2023; 261:114087. [PMID: 36646162 DOI: 10.1016/j.physbeh.2023.114087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/15/2023]
Abstract
We previously reported that appetite-enhancing peptides facilitated phasic contractions of the distal stomach and relaxed the forestomach via the dorsal vagal complex (DVC). The present study investigated the effects of anorectic substances on gastric reservoir function. The effects of oxytocin on the motility of the forestomach were examined in rats anesthetized with urethane-chloralose. Gastric motor responses were measured using an intragastric balloon. The fourth ventricular administration of oxytocin (0.1 - 1.0 nmol) increased intragastric pressure (IGP) in the forestomach in a dose-dependent manner. Conversely, the administration of oxytocin (0.3 nmol) suppressed phasic contractions of the distal stomach. These responses were opposite to those of appetite-enhancing peptides in previous studies. The oxytocin response in the forestomach was not observed after bilateral cervical vagotomy. The effects of oxytocin on forestomach motility were examined in animals that underwent ablation of the area postrema (AP) to clarify its involvement. Although the magnitude of the response to the fourth ventricular administration of oxytocin decreased, a significant response was still observed. A microinjection of oxytocin (3 pmol) into the AP, the left medial nucleus of the nucleus tractus solitarius (mNTS), the left commissural part of the NTS, or the left dorsal motor nucleus of the vagus was performed. The oxytocin injection into the AP and/or mNTS induced a rapid and large increase in IGP in the forestomach. Prior injection of L-368,899, an oxytocin receptor antagonist, into both the AP and mNTS attenuated the oxytocin response of the forestomach induced by fourth ventricular administration of oxytocin. These results indicate that oxytocin acts on the AP and/or mNTS to increase IGP in the forestomach via vagal preganglionic neurons.
Collapse
Affiliation(s)
- Motoi Kobashi
- Department of Oral Physiology, Faculty of Medicine, Dentistry and Pharmaceutical Science, Okayama University, Okayama, 700-8525, Japan.
| | - Yuichi Shimatani
- Department of Medical Engineering, Faculty of Engineering, Tokyo City University, Tokyo, 158-8557, Japan
| | - Masako Fujita
- Department of Oral Physiology, Faculty of Medicine, Dentistry and Pharmaceutical Science, Okayama University, Okayama, 700-8525, Japan
| |
Collapse
|
12
|
Ma J, Mistareehi A, Madas J, Kwiat AM, Bendowski K, Nguyen D, Chen J, Li DP, Furness JB, Powley TL, Cheng Z(J. Topographical organization and morphology of substance P (SP)-immunoreactive axons in the whole stomach of mice. J Comp Neurol 2023; 531:188-216. [PMID: 36385363 PMCID: PMC10499116 DOI: 10.1002/cne.25386] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/25/2022] [Accepted: 06/21/2022] [Indexed: 11/18/2022]
Abstract
Nociceptive afferents innervate the stomach and send signals centrally to the brain and locally to stomach tissues. Nociceptive afferents can be detected with a variety of different markers. In particular, substance P (SP) is a neuropeptide and is one of the most commonly used markers for nociceptive nerves in the somatic and visceral organs. However, the topographical distribution and morphological structure of SP-immunoreactive (SP-IR) axons and terminals in the whole stomach have not yet been fully determined. In this study, we labeled SP-IR axons and terminals in flat mounts of the ventral and dorsal halves of the stomach of mice. Flat-mount stomachs, including the longitudinal and circular muscular layers and the myenteric ganglionic plexus, were processed with SP primary antibody followed by fluorescent secondary antibody and then scanned using confocal microscopy. We found that (1) SP-IR axons and terminals formed an extensive network of fibers in the muscular layers and within the ganglia of the myenteric plexus of the whole stomach. (2) Many axons that ran in parallel with the long axes of the longitudinal and circular muscles were also immunoreactive for the vesicular acetylcholine transporter (VAChT). (3) SP-IR axons formed very dense terminal varicosities encircling individual neurons in the myenteric plexus; many of these were VAChT immunoreactive. (4) The regional density of SP-IR axons and terminals in the muscle and myenteric plexus varied in the following order from high to low: antrum-pylorus, corpus, fundus, and cardia. (5) In only the longitudinal and circular muscles, the regional density of SP-IR axon innervation from high to low were: antrum-pylorus, corpus, cardia, and fundus. (6) The innervation patterns of SP-IR axons and terminals in the ventral and dorsal stomach were comparable. Collectively, our data provide for the first time a map of the distribution and morphology of SP-IR axons and terminals in the whole stomach with single-cell/axon/synapse resolution. This work will establish an anatomical foundation for functional mapping of the SP-IR axon innervation of the stomach and its pathological remodeling in gastrointestinal diseases.
Collapse
Affiliation(s)
- Jichao Ma
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816
| | - Anas Mistareehi
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816
| | - Jazune Madas
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816
| | - Andrew M. Kwiat
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816
| | - Kohlton Bendowski
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816
| | - Duyen Nguyen
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816
| | - Jin Chen
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816
| | - De-Pei Li
- Center for Precision Medicine, Department of Medicine, School of Medicine, University of Missouri
| | - John B Furness
- Department of Anatomy & Physiology, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Terry L Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, IN 47906
| | - Zixi (Jack) Cheng
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816
| |
Collapse
|
13
|
Huizinga JD, Hussain A, Chen JH. Generation of Gut Motor Patterns Through Interactions Between Interstitial Cells of Cajal and the Intrinsic and Extrinsic Autonomic Nervous Systems. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1383:205-212. [PMID: 36587159 DOI: 10.1007/978-3-031-05843-1_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The musculature of the gastrointestinal tract is a vast network of collaborating excitable cell types. Embedded throughout are the interstitial cells of Cajal (ICC) intertwined with enteric nerves. ICC sense external stimuli such as distention, mediate nerve impulses to smooth muscle cells, and provide rhythmic excitation of the musculature. Neural circuitry involving both the intrinsic and extrinsic autonomic nervous systems, in collaboration with the ICC, orchestrate an array of motor patterns that serve to provide mixing of content to optimize digestion and absorption, microbiome homeostasis, storage, transit, and expulsion. ICC are specialized smooth muscle cells that generate rhythmic depolarization to the musculature and so provide the means for peristaltic and segmenting contractions. Some motor patterns are purely myogenic, but a neural stimulus initiates most, further depolarizing the primary pacemaker cells and the musculature and/or initiating transient pacemaker activity in stimulus-dependent secondary ICC pacemaker cells. From stomach to rectum, ICC networks rhythmically provide tracks along which contractions advance.
Collapse
Affiliation(s)
- Jan D Huizinga
- McMaster University, Farncombe Family Digestive Health Research Institute, Department of Medicine, Division of Gastroenterology, Hamilton, ON, Canada.
| | - Amer Hussain
- McMaster University, Farncombe Family Digestive Health Research Institute, Department of Medicine, Division of Gastroenterology, Hamilton, ON, Canada
| | - Ji-Hong Chen
- McMaster University, Farncombe Family Digestive Health Research Institute, Department of Medicine, Division of Gastroenterology, Hamilton, ON, Canada
| |
Collapse
|
14
|
Huizinga JD, Hussain A, Chen JH. Interstitial cells of Cajal and human colon motility in health and disease. Am J Physiol Gastrointest Liver Physiol 2021; 321:G552-G575. [PMID: 34612070 DOI: 10.1152/ajpgi.00264.2021] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Our understanding of human colonic motility, and autonomic reflexes that generate motor patterns, has increased markedly through high-resolution manometry. Details of the motor patterns are emerging related to frequency and propagation characteristics that allow linkage to interstitial cells of Cajal (ICC) networks. In studies on colonic motor dysfunction requiring surgery, ICC are almost always abnormal or significantly reduced. However, there are still gaps in our knowledge about the role of ICC in the control of colonic motility and there is little understanding of a mechanistic link between ICC abnormalities and colonic motor dysfunction. This review will outline the various ICC networks in the human colon and their proven and likely associations with the enteric and extrinsic autonomic nervous systems. Based on our extensive knowledge of the role of ICC in the control of gastrointestinal motility of animal models and the human stomach and small intestine, we propose how ICC networks are underlying the motor patterns of the human colon. The role of ICC will be reviewed in the autonomic neural reflexes that evoke essential motor patterns for transit and defecation. Mechanisms underlying ICC injury, maintenance, and repair will be discussed. Hypotheses are formulated as to how ICC dysfunction can lead to motor abnormalities in slow transit constipation, chronic idiopathic pseudo-obstruction, Hirschsprung's disease, fecal incontinence, diverticular disease, and inflammatory conditions. Recent studies on ICC repair after injury hold promise for future therapies.
Collapse
Affiliation(s)
- Jan D Huizinga
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Amer Hussain
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Ji-Hong Chen
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
| |
Collapse
|
15
|
Cao J, Wang X, Powley TL, Liu Z. Gastric neurons in the nucleus tractus solitarius are selective to the orientation of gastric electrical stimulation. J Neural Eng 2021; 18:10.1088/1741-2552/ac2ec6. [PMID: 34634781 PMCID: PMC8625070 DOI: 10.1088/1741-2552/ac2ec6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 10/11/2021] [Indexed: 01/02/2023]
Abstract
Objective.Gastric electrical stimulation (GES) is a bioelectric intervention for gastroparesis, obesity, and other functional gastrointestinal disorders. In a potential mechanism of action, GES activates the nerve endings of vagal afferent neurons and induces the vago-vagal reflex through the nucleus tractus solitarius (NTS) in the brainstem. However, it is unclear where and how to stimulate in order to optimize the vagal afferent responses.Approach.To address this question with electrophysiology in rats, we applied mild electrical currents to two serosal targets on the distal forestomach with dense distributions of vagal intramuscular arrays (IMAs) that innervated the circular and longitudinal smooth muscle layers. During stimulation, we recorded single and multi-unit responses from gastric neurons in NTS and evaluated how the recorded responses depended on the stimulus orientation and amplitude.Main results.We found that NTS responses were highly selective to the stimulus orientation for a range of stimulus amplitudes. The strongest responses were observed when the applied current flowed in the same direction as the IMAs in parallel with the underlying smooth muscle fibers. Our results suggest that gastric neurons in NTS may encode the orientation-specific activity of gastric smooth muscles relayed by vagal afferent neurons.Significance.This finding suggests that the orientation of GES is critical to effective engagement of vagal afferents and should be considered in light of the structural phenotypes of vagal terminals in the stomach.
Collapse
Affiliation(s)
- Jiayue Cao
- Department of Biomedical Engineering, University of Michigan Ann Arbor
| | - Xiaokai Wang
- Department of Biomedical Engineering, University of Michigan Ann Arbor
| | - Terry L. Powley
- Department of Psychological Sciences, Purdue University West Lafayette
| | - Zhongming Liu
- Department of Biomedical Engineering, University of Michigan Ann Arbor
- Department of Electrical Engineering and Computer Science, University of Michigan Ann Arbor
| |
Collapse
|
16
|
Loper H, Leinen M, Bassoff L, Sample J, Romero-Ortega M, Gustafson KJ, Taylor DM, Schiefer MA. Both high fat and high carbohydrate diets impair vagus nerve signaling of satiety. Sci Rep 2021; 11:10394. [PMID: 34001925 PMCID: PMC8128917 DOI: 10.1038/s41598-021-89465-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 04/26/2021] [Indexed: 11/23/2022] Open
Abstract
Obesity remains prevalent in the US. One potential treatment is vagus nerve stimulation (VNS), which activates the sensory afferents innervating the stomach that convey stomach volume and establish satiety. However, current VNS approaches and stimulus optimization could benefit from additional understanding of the underlying neural response to stomach distension. In this study, obesity-prone Sprague Dawley rats consumed a standard, high-carbohydrate, or high-fat diet for several months, leading to diet-induced obesity in the latter two groups. Under anesthesia, the neural activity in the vagus nerve was recorded with a penetrating microelectrode array while the stomach was distended with an implanted balloon. Vagal tone during distension was compared to baseline tone prior to distension. Responses were strongly correlated with stomach distension, but the sensitivity to distension was significantly lower in animals that had been fed the nonstandard diets. The results indicate that both high fat and high carbohydrate diets impair vagus activity.
Collapse
Affiliation(s)
- Hailley Loper
- Malcom Randall VA Medical Center, Gainesville, FL, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Monique Leinen
- Malcom Randall VA Medical Center, Gainesville, FL, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Logan Bassoff
- Malcom Randall VA Medical Center, Gainesville, FL, USA.,Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Jack Sample
- Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA.,College of Medicine & Life Sciences, University of Toledo, Toledo, OH, USA
| | - Mario Romero-Ortega
- Departments of Biomedical Engineering and Biomedical Sciences, University of Houston, Houston, TX, USA
| | - Kenneth J Gustafson
- Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Dawn M Taylor
- Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.,Department of Neurosciences, The Cleveland Clinic, Cleveland, OH, USA
| | - Matthew A Schiefer
- Malcom Randall VA Medical Center, Gainesville, FL, USA. .,Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA. .,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.
| |
Collapse
|
17
|
Page AJ. Gastrointestinal Vagal Afferents and Food Intake: Relevance of Circadian Rhythms. Nutrients 2021; 13:nu13030844. [PMID: 33807524 PMCID: PMC7998414 DOI: 10.3390/nu13030844] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/25/2021] [Accepted: 03/03/2021] [Indexed: 01/20/2023] Open
Abstract
Gastrointestinal vagal afferents (VAs) play an important role in food intake regulation, providing the brain with information on the amount and nutrient composition of a meal. This is processed, eventually leading to meal termination. The response of gastric VAs, to food-related stimuli, is under circadian control and fluctuates depending on the time of day. These rhythms are highly correlated with meal size, with a nadir in VA sensitivity and increase in meal size during the dark phase and a peak in sensitivity and decrease in meal size during the light phase in mice. These rhythms are disrupted in diet-induced obesity and simulated shift work conditions and associated with disrupted food intake patterns. In diet-induced obesity the dampened responses during the light phase are not simply reversed by reverting back to a normal diet. However, time restricted feeding prevents loss of diurnal rhythms in VA signalling in high fat diet-fed mice and, therefore, provides a potential strategy to reset diurnal rhythms in VA signalling to a pre-obese phenotype. This review discusses the role of the circadian system in the regulation of gastrointestinal VA signals and the impact of factors, such as diet-induced obesity and shift work, on these rhythms.
Collapse
Affiliation(s)
- Amanda J. Page
- Adelaide Medical School, University of Adelaide, Adelaide, SA 5000, Australia; ; Tel.: +61-8-8128-4840
- Nutrition, Diabetes and Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institution (SAHMRI), Adelaide, SA 5000, Australia
| |
Collapse
|
18
|
Tan ZT, Ward M, Phillips RJ, Zhang X, Jaffey DM, Chesney L, Rajwa B, Baronowsky EA, McAdams J, Powley TL. Stomach region stimulated determines effects on duodenal motility in rats. Am J Physiol Regul Integr Comp Physiol 2021; 320:R331-R341. [PMID: 33470183 PMCID: PMC7988774 DOI: 10.1152/ajpregu.00111.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 12/11/2020] [Accepted: 01/12/2021] [Indexed: 01/14/2023]
Abstract
Gastric electrical stimulation (GES) is used clinically to promote proximal GI emptying and motility. In acute experiments, we measured duodenal motor responses elicited by GES applied at 141 randomly chosen electrode sites on the stomach serosal surface. Overnight-fasted (H2O available) anesthetized male rats (n = 81) received intermittent biphasic GES for 5 min (20-s-on/40-s-off cycles; I = 0.3 mA; pw = 0.2 ms; 10 Hz). A strain gauge on the serosal surface of the proximal duodenum of each animal was used to evaluate baseline motor activity and the effect of GES. Using ratios of time blocks compared with a 15-min prestimulation baseline, we evaluated the effects of the 5-min stimulation on concurrent activity, on the 10 min immediately after the stimulation, and on the 15-min period beginning with the onset of stimulation. We mapped the magnitude of the duodenal response (three different motility indices) elicited from the 141 stomach sites. Post hoc electrode site maps associated with duodenal responses suggested three zones similar to the classic regions of forestomach, corpus, and antrum. Maximal excitatory duodenal motor responses were elicited from forestomach sites, whereas inhibitory responses occurred with stimulation of the corpus. Moderate excitatory duodenal responses occurred with stimulation of the antrum. Complex, weak inhibitory/excitatory responses were produced by stimulation at boundaries between stomach regions. Patterns of GES efficacies coincided with distributions of previously mapped vagal afferents, suggesting that excitation of the duodenum is strongest when GES electrodes are situated over stomach concentrations of vagal intramuscular arrays, putative stretch receptors in the muscle wall.
Collapse
Affiliation(s)
- Zhenjun T Tan
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Matthew Ward
- Department of Biomedical Engineering, Purdue University, West Lafayette, Indiana
| | - Robert J Phillips
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Xueguo Zhang
- Clunbury Scientific LLC, Bloomfield Hills, Michigan
| | - Deborah M Jaffey
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Logan Chesney
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Bartek Rajwa
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana
| | | | - Jennifer McAdams
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Terry L Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| |
Collapse
|
19
|
Gautron L. The Phantom Satiation Hypothesis of Bariatric Surgery. Front Neurosci 2021; 15:626085. [PMID: 33597843 PMCID: PMC7882491 DOI: 10.3389/fnins.2021.626085] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/06/2021] [Indexed: 01/26/2023] Open
Abstract
The excitation of vagal mechanoreceptors located in the stomach wall directly contributes to satiation. Thus, a loss of gastric innervation would normally be expected to result in abrogated satiation, hyperphagia, and unwanted weight gain. While Roux-en-Y-gastric bypass (RYGB) inevitably results in gastric denervation, paradoxically, bypassed subjects continue to experience satiation. Inspired by the literature in neurology on phantom limbs, I propose a new hypothesis in which damage to the stomach innervation during RYGB, including its vagal supply, leads to large-scale maladaptive changes in viscerosensory nerves and connected brain circuits. As a result, satiation may continue to arise, sometimes at exaggerated levels, even in subjects with a denervated or truncated stomach. The same maladaptive changes may also contribute to dysautonomia, unexplained pain, and new emotional responses to eating. I further revisit the metabolic benefits of bariatric surgery, with an emphasis on RYGB, in the light of this phantom satiation hypothesis.
Collapse
Affiliation(s)
- Laurent Gautron
- Department of Internal Medicine, Center for Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| |
Collapse
|
20
|
Hirakawa M, Yokoyama T, Yamamoto Y, Saino T. Distribution and morphology of P2X3-immunoreactive subserosal afferent nerve endings in the rat gastric antrum. J Comp Neurol 2020; 529:2014-2028. [PMID: 33190284 DOI: 10.1002/cne.25069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/27/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022]
Abstract
The present study investigated the morphological characteristics of subserosal afferent nerve endings with immunoreactivity for the P2X3 purinoceptor (P2X3) in the rat stomach by immunohistochemistry of whole-mount preparations using confocal scanning laser microscopy. P2X3 immunoreactivity was observed in subserosal nerve endings proximal and lateral to the gastric sling muscles in the distal antrum of the lesser curvature. Parent axons ramified into several lamellar processes to form net-like complex structures that extended two-dimensionally in every direction on the surface of the longitudinal smooth muscle layer. The axon terminals in the periphery of P2X3-immunoreactive net-like structures were flat and looped or leaf-like in shape. Some net-like lamellar structures and their axon terminals with P2X3 immunoreactivity were also immunoreactive for P2X2. P2X3-immunoreactive nerve fibers forming net-like terminal structures were closely surrounded by S100B-immunoreactive terminal Schwann cells, whereas axon terminals twined around these cells and extended club-, knob-, or thread-like protrusions in the surrounding tissues. Furthermore, a retrograde tracing method using fast blue dye indicated that most of these nerve endings originated from the nodose ganglia of the vagus nerve. These results suggest that P2X3-immunoreactive subserosal nerve endings have morphological characteristics of mechanoreceptors and contribute to sensation of a mechanical deformation of the distal antral wall associated with antral peristalsis.
Collapse
Affiliation(s)
- Masato Hirakawa
- Department of Anatomy (Cell Biology), Iwate Medical University, Yahaba-cho, Japan
| | - Takuya Yokoyama
- Department of Anatomy (Cell Biology), Iwate Medical University, Yahaba-cho, Japan
| | - Yoshio Yamamoto
- Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan
| | - Tomoyuki Saino
- Department of Anatomy (Cell Biology), Iwate Medical University, Yahaba-cho, Japan
| |
Collapse
|
21
|
Salmaso C, Toniolo I, Fontanella CG, Da Roit P, Albanese A, Polese L, Stefanini C, Foletto M, Carniel EL. Computational Tools for the Reliability Assessment and the Engineering Design of Procedures and Devices in Bariatric Surgery. Ann Biomed Eng 2020; 48:2466-2483. [PMID: 32472365 DOI: 10.1007/s10439-020-02542-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 05/27/2020] [Indexed: 01/10/2023]
Abstract
Obesity is one of the main health concerns worldwide. Bariatric Surgery (BS) is the gold standard treatment for severe obesity. Nevertheless, unsatisfactory weight loss and complications can occur. The efficacy of BS is mainly defined on experiential bases; therefore, a more rational approach is required. The here reported activities aim to show the strength of experimental and computational biomechanics in evaluating stomach functionality depending on bariatric procedure. The experimental activities consisted in insufflation tests on samples of swine stomach to assess the pressure-volume behaviour both in pre- and post-surgical configurations. The investigation pertained to two main bariatric procedures: adjustable gastric banding (AGB) and laparoscopic sleeve gastrectomy (LSG). Subsequently, a computational model of the stomach was exploited to validate and to integrate results from experimental activities, as well as to broad the investigation to a wider scenario of surgical procedures and techniques. Furthermore, the computational approach allowed analysing stress and strain fields within stomach tissues because of food ingestion. Such fields elicit mechanical stimulation of gastric receptors, contributing to release satiety signals. Pressure-volume curves assessed stomach capacity and stiffness according to the surgical procedure. Both AGB and LSG proved to reduce stomach capacity and to increase stiffness, with markedly greater effect for LSG. At an internal pressure of 5 kPa, outcomes showed that in pre-surgical configuration the inflated volume was about 1000 mL, after AGB the inflated volume was slightly lower, while after LSG it fell significantly, reaching 100 mL. Computational modelling techniques showed the influence of bariatric intervention on mechanical stimulation of gastric receptors due to food ingestion. AGB markedly enhanced the mechanical stimulation within the fundus region, while LSG significantly reduced stress and strain intensities. Further computational investigations revealed the potentialities of hybrid endoscopic procedures to induce both reduction of stomach capacity and enhancement of gastric receptors mechanical stimulation. In conclusion, biomechanics proved to be useful for the investigation of BS effects. Future exploitations of the biomechanical methods may largely improve BS reliability, efficacy and penetration rate.
Collapse
Affiliation(s)
- C Salmaso
- Centre for Mechanics of Biological Materials, University of Padova, Padua, Italy
- Department of Industrial Engineering, University of Padova, Via Venezia, 1, 35131, Padua, Italy
| | - I Toniolo
- Centre for Mechanics of Biological Materials, University of Padova, Padua, Italy.
- Department of Industrial Engineering, University of Padova, Via Venezia, 1, 35131, Padua, Italy.
| | - C G Fontanella
- Centre for Mechanics of Biological Materials, University of Padova, Padua, Italy
- Department of Industrial Engineering, University of Padova, Via Venezia, 1, 35131, Padua, Italy
| | - P Da Roit
- Department of Industrial Engineering, University of Padova, Via Venezia, 1, 35131, Padua, Italy
| | - A Albanese
- Department of Surgery, Oncology and Gastroenterology, University of Padova, Padua, Italy
| | - L Polese
- Centre for Mechanics of Biological Materials, University of Padova, Padua, Italy
- Department of Surgery, Oncology and Gastroenterology, University of Padova, Padua, Italy
| | - C Stefanini
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - M Foletto
- Centre for Mechanics of Biological Materials, University of Padova, Padua, Italy
- Department of Surgery, Oncology and Gastroenterology, University of Padova, Padua, Italy
| | - E L Carniel
- Centre for Mechanics of Biological Materials, University of Padova, Padua, Italy
- Department of Industrial Engineering, University of Padova, Via Venezia, 1, 35131, Padua, Italy
| |
Collapse
|
22
|
Lu KH, Cao J, Phillips R, Powley TL, Liu Z. Acute effects of vagus nerve stimulation parameters on gastric motility assessed with magnetic resonance imaging. Neurogastroenterol Motil 2020; 32:e13853. [PMID: 32297404 PMCID: PMC7872206 DOI: 10.1111/nmo.13853] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 02/24/2020] [Accepted: 03/19/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Vagus nerve stimulation (VNS) is an emerging bioelectronic therapy for regulating food intake and controlling gastric motility. However, the effects of different VNS parameters and polarity on postprandial gastric motility remain incompletely characterized. METHODS In anesthetized rats (N = 3), we applied monophasic electrical stimuli to the left cervical vagus and recorded compound nerve action potential (CNAP) as a measure of nerve response. We evaluated to what extent afferent or efferent pathway could be selectively activated by monophasic VNS. In a different group of rats (N = 13), we fed each rat a gadolinium-labeled meal and scanned the rat stomach with oral contrast-enhanced magnetic resonance imaging (MRI) while the rat was anesthetized. We evaluated the antral and pyloric motility as a function of pulse amplitude (0.13, 0.25, 0.5, 1 mA), width (0.13, 0.25, 0.5 ms), frequency (5, 10 Hz), and polarity of VNS. KEY RESULTS Monophasic VNS activated efferent and afferent pathways with about 67% and 82% selectivity, respectively. Primarily afferent VNS increased antral motility across a wide range of parameters. Primarily efferent VNS induced a significant decrease in antral motility as the stimulus intensity increased (R = -.93, P < .05 for 5 Hz, R = -.85, P < .05 for 10 Hz). The VNS with either polarity tended to promote pyloric motility to a greater extent given increasing stimulus intensity. CONCLUSIONS AND INFERENCES Monophasic VNS biased toward the afferent pathway is potentially more effective for facilitating occlusive contractions than that biased toward the efferent pathway.
Collapse
Affiliation(s)
- Kun-Han Lu
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA,Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA,Correspondence: Kun-Han Lu, PhD, Postdoctoral Research Associate, Weldon School of Biomedical Engineering, College of Engineering, Purdue University, 206 S. Martin Jischke Dr., West Lafayette, IN 47907, USA, Phone: +1 765 714 8776,
| | - Jiayue Cao
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Robert Phillips
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA
| | - Terry L Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA,Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA
| | - Zhongming Liu
- Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA,Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
23
|
Wang YB, de Lartigue G, Page AJ. Dissecting the Role of Subtypes of Gastrointestinal Vagal Afferents. Front Physiol 2020; 11:643. [PMID: 32595525 PMCID: PMC7300233 DOI: 10.3389/fphys.2020.00643] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/20/2020] [Indexed: 12/22/2022] Open
Abstract
Gastrointestinal (GI) vagal afferents convey sensory signals from the GI tract to the brain. Numerous subtypes of GI vagal afferent have been identified but their individual roles in gut function and feeding regulation are unclear. In the past decade, technical approaches to selectively target vagal afferent subtypes and to assess their function has significantly progressed. This review examines the classification of GI vagal afferent subtypes and discusses the current available techniques to study vagal afferents. Investigating the distribution of GI vagal afferent subtypes and understanding how to access and modulate individual populations are essential to dissect their fundamental roles in the gut-brain axis.
Collapse
Affiliation(s)
- Yoko B Wang
- Vagal Afferent Research Group, Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
| | - Guillaume de Lartigue
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL, United States.,Center for Integrative Cardiovascular and Metabolic Disease, University of Florida, Gainesville, FL, United States
| | - Amanda J Page
- Vagal Afferent Research Group, Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia.,Nutrition, Diabetes and Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| |
Collapse
|
24
|
Yu CD, Xu QJ, Chang RB. Vagal sensory neurons and gut-brain signaling. Curr Opin Neurobiol 2020; 62:133-140. [PMID: 32380360 PMCID: PMC7560965 DOI: 10.1016/j.conb.2020.03.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 12/18/2022]
Abstract
Our understanding of the gut system has been revolutionized over the past decade, in particular regarding its role in immune control and psychological regulation. The vagus nerve is a crucial link between gut and brain, transmitting diverse gut-derived signals, and has been implicated in many gastrointestinal, neurological, and immunological disorders. Using state-of-the-art technologies including single-cell genomic analysis, real-time neural activity recording, trans-synaptic tracing, and electron microscopy, novel physiological functions of vagal gut afferents have been uncovered, and new gut-to-brain pathways have been revealed. Here, we review the most recent findings on vagal sensory neurons and the gut-brain signaling, focusing on the anatomical basis and the underlying molecular and cellular mechanisms. Such new discoveries explain some of the old puzzling problems and also raise new questions in this exciting and rapidly growing field.
Collapse
Affiliation(s)
- Chuyue D Yu
- Department of Neuroscience, Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, United States; Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Qian J Xu
- Department of Neuroscience, Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, United States; Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Rui B Chang
- Department of Neuroscience, Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06510, United States.
| |
Collapse
|
25
|
Milkova N, Parsons SP, Ratcliffe E, Huizinga JD, Chen JH. On the nature of high-amplitude propagating pressure waves in the human colon. Am J Physiol Gastrointest Liver Physiol 2020; 318:G646-G660. [PMID: 32068445 PMCID: PMC7191456 DOI: 10.1152/ajpgi.00386.2019] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Characterization of high-amplitude propagating pressure waves (HAPWs or HAPCs) plays a key role in diagnosis of colon dysmotility using any type of colonic manometry. With the introduction of high-resolution manometry, more insight is gained into this most prominent propulsive motor pattern. Here, we use a water-perfused catheter with 84 sensors with intervals between measuring points of 1 cm throughout the colon, for 6-8 h, in 19 healthy subjects. The catheter contained a balloon to evoke distention. We explored as stimuli a meal, balloon distention, oral prucalopride, and bisacodyl injection, with a goal to optimally evoke HAPWs. We developed a quantitative measure of HAPW activity, the "HAPW Index." Our protocol elicited 290 HAPWs. 21% of HAPWs were confined to the proximal colon with an average amplitude of 75.3 ± 3.3 mmHg and an average HAPW Index of 440 ± 58 mmHg·m·s. 29% of HAPWs started in the proximal colon and ended in the transverse or descending colon, with an average amplitude of 87.9 ± 3.1 mmHg and an average HAPW Index of 3,344 ± 356 mmHg·m·s. Forty-nine percent of HAPWs started and ended in the transverse or descending colon with an average amplitude of 109.3 ± 3.3 mmHg and an average HAPW Index of 2,071 ± 195 mmHg·m·s. HAPWs with and without simultaneous pressure waves (SPWs) initiated the colo-anal reflex, often abolishing 100% of anal sphincter pressure. Rectal bisacodyl and proximal balloon distention were the most optimal stimuli to evoke HAPWs. These measures now allow for a confident diagnosis of abnormal motility in patients with colonic motor dysfunction.NEW & NOTEWORTHY High-amplitude propagating pressure waves (HAPWs) were characterized using 84 sensors throughout the entire colon in healthy subjects, taking note of site of origin, site of termination, amplitude, and velocity, and to identify optimal stimuli to evoke HAPWs. Three categories of HAPWs were identified, including the associated colo-anal reflex. Proximal balloon distention and rectal bisacodyl were recognized as reliable stimuli for evoking HAPWs, and a HAPW Index was devised to quantify this essential colonic motor pattern.
Collapse
Affiliation(s)
- Natalija Milkova
- McMaster University, Department of Medicine, Division of Gastroenterology, Farncombe Family Digestive Health Research Institute, Hamilton, Ontario, Canada
| | - Sean P. Parsons
- McMaster University, Department of Medicine, Division of Gastroenterology, Farncombe Family Digestive Health Research Institute, Hamilton, Ontario, Canada
| | - Elyanne Ratcliffe
- McMaster University, Department of Medicine, Division of Gastroenterology, Farncombe Family Digestive Health Research Institute, Hamilton, Ontario, Canada
| | - Jan D. Huizinga
- McMaster University, Department of Medicine, Division of Gastroenterology, Farncombe Family Digestive Health Research Institute, Hamilton, Ontario, Canada
| | - Ji-Hong Chen
- McMaster University, Department of Medicine, Division of Gastroenterology, Farncombe Family Digestive Health Research Institute, Hamilton, Ontario, Canada
| |
Collapse
|
26
|
Sensory nerve endings arising from single spinal afferent neurons that innervate both circular muscle and myenteric ganglia in mouse colon: colon-brain axis. Cell Tissue Res 2020; 381:25-34. [DOI: 10.1007/s00441-020-03192-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/19/2020] [Indexed: 10/25/2022]
|
27
|
Powley TL, Jaffey DM, McAdams J, Baronowsky EA, Black D, Chesney L, Evans C, Phillips RJ. Vagal innervation of the stomach reassessed: brain-gut connectome uses smart terminals. Ann N Y Acad Sci 2019; 1454:14-30. [PMID: 31268562 DOI: 10.1111/nyas.14138] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/07/2019] [Accepted: 05/16/2019] [Indexed: 01/06/2023]
Abstract
Brain-gut neural communications have long been considered limited because of conspicuous numerical mismatches. The vagus, the parasympathetic nerve connecting brain and gut, contains thousands of axons, whereas the gastrointestinal (GI) tract contains millions of intrinsic neurons in local plexuses. The numerical paradox was initially recognized in terms of efferent projections, but the number of afferents, which comprise the majority (≈ 80%) of neurites in the vagus, is also relatively small. The present survey of recent morphological observations suggests that vagal terminals, and more generally autonomic and visceral afferent arbors in the stomach as well as throughout the gut, elaborate arbors that are extensive, regionally specialized, polymorphic, polytopic, and polymodal, commonly with multiplicities of receptors and binding sites-smart terminals. The morphological specializations and dynamic tuning of one-to-many efferent projections and many-to-one convergences of contacts onto afferents create a complex architecture capable of extensive peripheral integration in the brain-gut connectome and offset many of the disparities between axon and target numbers. Appreciating this complex architecture can help in the design of therapies for GI disorders.
Collapse
Affiliation(s)
- Terry L Powley
- Behavioral Neuroscience Area, Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Deborah M Jaffey
- Behavioral Neuroscience Area, Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Jennifer McAdams
- Behavioral Neuroscience Area, Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Elizabeth A Baronowsky
- Behavioral Neuroscience Area, Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Diana Black
- Behavioral Neuroscience Area, Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Logan Chesney
- Behavioral Neuroscience Area, Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Charlene Evans
- Behavioral Neuroscience Area, Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| | - Robert J Phillips
- Behavioral Neuroscience Area, Department of Psychological Sciences, Purdue University, West Lafayette, Indiana
| |
Collapse
|
28
|
Cao J, Lu KH, Oleson ST, Phillips RJ, Jaffey D, Hendren CL, Powley TL, Liu Z. Gastric stimulation drives fast BOLD responses of neural origin. Neuroimage 2019; 197:200-211. [PMID: 31029867 DOI: 10.1016/j.neuroimage.2019.04.064] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 04/02/2019] [Accepted: 04/23/2019] [Indexed: 11/27/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) is commonly thought to be too slow to capture any neural dynamics faster than 0.1 Hz. However, recent findings demonstrate the feasibility of detecting fMRI activity at higher frequencies beyond 0.2 Hz. The origin, reliability, and generalizability of fast fMRI responses are still under debate and await confirmation through animal experiments with fMRI and invasive electrophysiology. Here, we acquired single-echo and multi-echo fMRI, as well as local field potentials, from anesthetized rat brains given gastric electrical stimulation modulated at 0.2, 0.4 and 0.8 Hz. Such gastric stimuli could drive widespread fMRI responses at corresponding frequencies from the somatosensory and cingulate cortices. Such fast fMRI responses were linearly dependent on echo times and thus indicative of blood oxygenation level dependent nature (BOLD). Local field potentials recorded during the same gastric stimuli revealed transient and phase-locked broadband neural responses, preceding the fMRI responses by as short as 0.5 s. Taken together, these results suggest that gastric stimulation can drive widespread and rapid fMRI responses of BOLD and neural origin, lending support to the feasibility of using fMRI to detect rapid changes in neural activity up to 0.8 Hz under visceral stimulation.
Collapse
Affiliation(s)
- Jiayue Cao
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States; Purdue Institute of Integrative Neuroscience, Purdue University, West Lafayette, IN, United States
| | - Kun-Han Lu
- School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, United States; Purdue Institute of Integrative Neuroscience, Purdue University, West Lafayette, IN, United States
| | - Steven T Oleson
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Robert J Phillips
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, United States; Purdue Institute of Integrative Neuroscience, Purdue University, West Lafayette, IN, United States
| | - Deborah Jaffey
- Department of Psychological Sciences, Purdue University, West Lafayette, IN, United States
| | - Christina L Hendren
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States
| | - Terry L Powley
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States; Department of Psychological Sciences, Purdue University, West Lafayette, IN, United States; Purdue Institute of Integrative Neuroscience, Purdue University, West Lafayette, IN, United States
| | - Zhongming Liu
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States; Department of Psychological Sciences, Purdue University, West Lafayette, IN, United States; Purdue Institute of Integrative Neuroscience, Purdue University, West Lafayette, IN, United States.
| |
Collapse
|
29
|
Chen JH, Parsons SP, Shokrollahi M, Wan A, Vincent AD, Yuan Y, Pervez M, Chen WL, Xue M, Zhang KK, Eshtiaghi A, Armstrong D, Bercik P, Moayyedi P, Greenwald E, Ratcliffe EM, Huizinga JD. Characterization of Simultaneous Pressure Waves as Biomarkers for Colonic Motility Assessed by High-Resolution Colonic Manometry. Front Physiol 2018; 9:1248. [PMID: 30294277 PMCID: PMC6159752 DOI: 10.3389/fphys.2018.01248] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 08/17/2018] [Indexed: 12/31/2022] Open
Abstract
Simultaneous pressure waves (SPWs) in manometry recordings of the human colon have been associated with gas expulsion. Our hypothesis was that the SPW might be a critical component of most colonic motor functions, and hence might act as a biomarker for healthy colon motility. To that end, we performed high-resolution colonic manometry (HRCM), for the first time using an 84-sensor (1 cm spaced) water-perfused catheter, in 17 healthy volunteers. Intraluminal pressure patterns were recorded during baseline, proximal and rectal balloon distention, after a meal and following proximal and rectal luminal bisacodyl administration. Quantification was performed using software, based on Image J, developed during this study. Gas expulsion was always associated with SPWs, furthermore, SPWs were associated with water or balloon expulsion. SPWs were prominently emerging at the termination of proximal high amplitude propagating pressure waves (HAPWs); we termed this motor pattern HAPW-SPWs; hence, SPWs were often not a pan-colonic event. SPWs and HAPW-SPWs were observed at baseline with SPW amplitudes of 12.0 ± 8.5 mmHg and 20.2 ± 7.2 mmHg respectively. The SPW occurrence and amplitude significantly increased in response to meal, balloon distention and luminal bisacodyl, associated with 50.3% anal sphincter relaxation at baseline, which significantly increased to 59.0% after a meal, and 69.1% after bisacodyl. Often, full relaxation was achieved. The SPWs associated with gas expulsion had a significantly higher amplitude compared to SPWs without gas expulsion. SPWs could be seen to consist of clusters of high frequency pressure waves, likely associated with a cluster of fast propagating, circular muscle contractions. SPWs were occasionally observed in a highly rhythmic pattern at 1.8 ± 1.2 cycles/min. Unlike HAPWs, the SPWs did not obliterate haustral boundaries thereby explaining how gas can be expelled while solid content can remain restrained by the haustral boundaries. In conclusion, the SPW may become a biomarker for normal gas transit, the gastrocolonic reflex and extrinsic neural reflexes. The SPW assessment reveals coordination of activities in the colon, rectum and anal sphincters. SPWs may become of diagnostic value in patients with colonic dysmotility.
Collapse
Affiliation(s)
- Ji-Hong Chen
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Sean P Parsons
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Mitra Shokrollahi
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Andrew Wan
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Alexander D Vincent
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Yuhong Yuan
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada.,Sun Yat-sen University, Guangdong, China
| | - Maham Pervez
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Wu Lan Chen
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Mai Xue
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Kailai K Zhang
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Arshia Eshtiaghi
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - David Armstrong
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Premsyl Bercik
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Paul Moayyedi
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Eric Greenwald
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| | - Elyanne M Ratcliffe
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada.,Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - Jan D Huizinga
- Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| |
Collapse
|
30
|
Trancikova A, Kovacova E, Ru F, Varga K, Brozmanova M, Tatar M, Kollarik M. Distinct Expression of Phenotypic Markers in Placodes- and Neural Crest-Derived Afferent Neurons Innervating the Rat Stomach. Dig Dis Sci 2018; 63:383-394. [PMID: 29275446 DOI: 10.1007/s10620-017-4883-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 12/12/2017] [Indexed: 01/10/2023]
Abstract
BACKGROUND Visceral pain is initiated by activation of primary afferent neurons among which the capsaicin-sensitive (TRPV1-positive) neurons play an important role. The stomach is a common source of visceral pain. Similar to other organs, the stomach receives dual spinal and vagal afferent innervation. Developmentally, spinal dorsal root ganglia (DRG) and vagal jugular neurons originate from embryonic neural crest and vagal nodose neurons originate from placodes. In thoracic organs the neural crest- and placodes-derived TRPV1-positive neurons have distinct phenotypes differing in activation profile, neurotrophic regulation and reflex responses. It is unknown to whether such distinction exists in the stomach. AIMS We hypothesized that gastric neural crest- and placodes-derived TRPV1-positive neurons express phenotypic markers indicative of placodes and neural crest phenotypes. METHODS Gastric DRG and vagal neurons were retrogradely traced by DiI injected into the rat stomach wall. Single-cell RT-PCR was performed on traced gastric neurons. RESULTS Retrograde tracing demonstrated that vagal gastric neurons locate exclusively into the nodose portion of the rat jugular/petrosal/nodose complex. Gastric DRG TRPV1-positive neurons preferentially expressed markers PPT-A, TrkA and GFRα3 typical for neural crest-derived TRPV1-positive visceral neurons. In contrast, gastric nodose TRPV1-positive neurons preferentially expressed markers P2X2 and TrkB typical for placodes-derived TRPV1-positive visceral neurons. Differential expression of neural crest and placodes markers was less pronounced in TRPV1-negative DRG and nodose populations. CONCLUSIONS There are phenotypic distinctions between the neural crest-derived DRG and placodes-derived vagal nodose TRPV1-positive neurons innervating the rat stomach that are similar to those described in thoracic organs.
Collapse
Affiliation(s)
- Alzbeta Trancikova
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Biomedical Center Martin JFM CU, Malá Hora 4C, 036 01, Martin, Slovakia
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Department of Pathophysiology JFM CU, Malá Hora 4C, 036 01, Martin, Slovakia
| | - Eva Kovacova
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Biomedical Center Martin JFM CU, Malá Hora 4C, 036 01, Martin, Slovakia
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Department of Pathophysiology JFM CU, Malá Hora 4C, 036 01, Martin, Slovakia
| | - Fei Ru
- Department of Medicine, The Johns Hopkins University School of Medicine, Johns Hopkins Asthma Center, RM 1A.2, 5501 Hopkins Bayview Circle, Baltimore, MD, 21224, USA
| | - Kristian Varga
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Biomedical Center Martin JFM CU, Malá Hora 4C, 036 01, Martin, Slovakia
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Department of Pathophysiology JFM CU, Malá Hora 4C, 036 01, Martin, Slovakia
| | - Mariana Brozmanova
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Biomedical Center Martin JFM CU, Malá Hora 4C, 036 01, Martin, Slovakia
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Department of Pathophysiology JFM CU, Malá Hora 4C, 036 01, Martin, Slovakia
| | - Milos Tatar
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Biomedical Center Martin JFM CU, Malá Hora 4C, 036 01, Martin, Slovakia
- Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Department of Pathophysiology JFM CU, Malá Hora 4C, 036 01, Martin, Slovakia
| | - Marian Kollarik
- Department of Medicine, The Johns Hopkins University School of Medicine, Johns Hopkins Asthma Center, RM 1A.2, 5501 Hopkins Bayview Circle, Baltimore, MD, 21224, USA.
| |
Collapse
|
31
|
Calderón-Garcidueñas L, Reynoso-Robles R, Pérez-Guillé B, Mukherjee PS, Gónzalez-Maciel A. Combustion-derived nanoparticles, the neuroenteric system, cervical vagus, hyperphosphorylated alpha synuclein and tau in young Mexico City residents. ENVIRONMENTAL RESEARCH 2017; 159:186-201. [PMID: 28803148 DOI: 10.1016/j.envres.2017.08.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 08/02/2017] [Accepted: 08/04/2017] [Indexed: 06/07/2023]
Abstract
Mexico City (MC) young residents are exposed to high levels of fine particulate matter (PM2.5), have high frontal concentrations of combustion-derived nanoparticles (CDNPs), accumulation of hyperphosphorylated aggregated α-synuclein (α-Syn) and early Parkinson's disease (PD). Swallowed CDNPs have easy access to epithelium and submucosa, damaging gastrointestinal (GI) barrier integrity and accessing the enteric nervous system (ENS). This study is focused on the ENS, vagus nerves and GI barrier in young MC v clean air controls. Electron microscopy of epithelial, endothelial and neural cells and immunoreactivity of stomach and vagus to phosphorylated ɑ-synuclein Ser129 and Hyperphosphorylated-Tau (Htau) were evaluated and CDNPs measured in ENS. CDNPs were abundant in erythrocytes, unmyelinated submucosal, perivascular and intramuscular nerve fibers, ganglionic neurons and vagus nerves and associated with organelle pathology. ɑSyn and Htau were present in 25/27 MC gastric,15/26 vagus and 18/27 gastric and 2/26 vagus samples respectively. We strongly suggest CDNPs are penetrating and damaging the GI barrier and reaching preganglionic parasympathetic fibers and the vagus nerve. This work highlights the potential role of CDNPs in the neuroenteric hyperphosphorylated ɑ-Syn and tau pathology as seen in Parkinson and Alzheimer's diseases. Highly oxidative, ubiquitous CDNPs constitute a biologically plausible path into Parkinson's and Alzheimer's pathogenesis.
Collapse
Affiliation(s)
- Lilian Calderón-Garcidueñas
- The University of Montana, Missoula, MT 59812, USA; Universidad del Valle de México, Mexico City 14370, Mexico.
| | | | | | | | | |
Collapse
|
32
|
Huizinga JD. Commentary: Phase-amplitude coupling at the organism level: The amplitude of spontaneous alpha rhythm fluctuations varies with the phase of the infra-slow gastric basal rhythm. Front Neurosci 2017; 11:102. [PMID: 28303088 PMCID: PMC5332408 DOI: 10.3389/fnins.2017.00102] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 02/17/2017] [Indexed: 01/09/2023] Open
Affiliation(s)
- Jan D Huizinga
- Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University Hamilton, ON, Canada
| |
Collapse
|
33
|
Intraluminal pressure patterns in the human colon assessed by high-resolution manometry. Sci Rep 2017; 7:41436. [PMID: 28216670 PMCID: PMC5316981 DOI: 10.1038/srep41436] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 12/13/2016] [Indexed: 02/08/2023] Open
Abstract
Assessment of colonic motor dysfunction is rarely done because of inadequate methodology and lack of knowledge about normal motor patterns. Here we report on elucidation of intraluminal pressure patterns using High Resolution Colonic Manometry during a baseline period and in response to a meal, in 15 patients with constipation, chronically dependent on laxatives, 5 healthy volunteers and 9 patients with minor, transient, IBS-like symptoms but no sign of constipation. Simultaneous pressure waves (SPWs) were the most prominent propulsive motor pattern, associated with gas expulsion and anal sphincter relaxation, inferred to be associated with fast propagating contractions. Isolated pressure transients occurred in most sensors, ranging in amplitude from 5–230 mmHg. Rhythmic haustral boundary pressure transients occurred at sensors about 4–5 cm apart. Synchronized haustral pressure waves, covering 3–5 cm of the colon occurred to create a characteristic intrahaustral cyclic motor pattern at 3–6 cycles/min, propagating in mixed direction. This activity abruptly alternated with erratic patterns resembling the segmentation motor pattern of the small intestine. High amplitude propagating pressure waves (HAPWs) were too rare to contribute to function assessment in most subjects. Most patients, dependent on laxatives for defecation, were able to generate normal motor patterns in response to a meal.
Collapse
|
34
|
Chen H, Zhu W, Lu J, Fan J, Sun L, Feng X, Liu H, Zhang Z, Wang Y. The Effects of Auricular Electro-Acupuncture on Ameliorating the Dysfunction of Interstitial Cells of Cajal Networks and nNOSmRNA Expression in Antrum of STZ-Induced Diabetic Rats. PLoS One 2016; 11:e0166638. [PMID: 27930657 PMCID: PMC5145159 DOI: 10.1371/journal.pone.0166638] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 11/01/2016] [Indexed: 12/27/2022] Open
Abstract
BACKGROUD Interstitial cells of Cajal (ICCs) and nNOS play a crucial role in diabetic gastrointestinal dysmotility(DGD). Our previous study found that electro-acupuncture(EA) on ear point 'stomach' could repair the gastric dysrhythmias in rats induced by rectal distention(RD) after meal. However, little were known about the possible effect of auricular electro-acupuncture (AEA) on diabetic rats. Thus, we designed this study to investigate the effect of AEA on streptozotocin(STZ)-induced diabetic rats. METHOD Forty male Sprague_Dawley (SD) rats were injected with STZ, at the end of 8th week after injection, animals were randomly divided into four groups and received 2 weeks-treatment(10 times) respectively: control group(CON,n = 10, no stimulation), sham auricular electro-acupuncture group(SEA,n = 10, low frequency EA on earlobes), auricular eletro-acupuncture group(AEA,n = 10, low frequency EA on ear point 'stomach'), and ST-36 group(ST-36,n = 10, low frequency EA on ST-36). Gastrointestinal (GI) motility was measured by GI transit rate. ICCs(c-kit+ expression) in antrum were analyzed by Immunohistochemistry and western blotting. NO level in blood serum were detected by Griess Reagent, and nNOSmRNA expression in antrum were determined by Real-time PCR. RESULTS GI transit rate and ICCs(c-kit+ expression) in antrum of AEA group have the tendency to increase compared with CON group, but had no statistics difference (P>0.05). nNOSmRNA expression in antrum of AEA group was dramatically increased compared with CON group (P = 0.037). CONCLUSIONS Low frequency EA on ear 'stomach' point could significantly up-regulate nNOS mRNA expression and ameliorate the ICCs networks partly in gastric antrum of STZ -induced diabetic rats, which may has benefits on regulating the GI motility.
Collapse
Affiliation(s)
- Huan Chen
- Department of Acupuncture, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Weijian Zhu
- Department of Acupuncture, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jing Lu
- Department of Acupuncture, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Jinqing Fan
- Department of Acupuncture, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Luning Sun
- Department of Pharmacy, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Xiaoke Feng
- Department of Traditional Chinese Medicine, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Hao Liu
- Department of Traditional Chinese Medicine, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Zhaohui Zhang
- Department of Acupuncture, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yongqing Wang
- Department of Pharmacy, The First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| |
Collapse
|
35
|
Abstract
Ineffective esophageal motility (IEM) is characterized by low to very low amplitude propulsive contractions in the distal esophagus, hence primarily affecting the smooth muscle part of the esophagus. IEM is often found in patients with dysphagia or heartburn and is commonly associated with gastroesophageal reflux disease. IEM is assumed to be associated with ineffective bolus transport; however, this can be verified using impedance measurements or evaluation of a barium coated marshmallow swallow. Furthermore, water swallows may not assess accurately the motor capabilities of the esophagus, since contraction amplitude is strongly determined by the size and consistency of the bolus. The “peristaltic reserve” of the esophagus can be evaluated by multiple rapid swallows that, after a period of diglutative inhibition, normally give a powerful peristaltic contraction suggestive of the integrity of neural orchestration and smooth muscle action. The amplitude of contraction is determined by a balance between intrinsic excitatory cholinergic, inhibitory nitrergic, as well as postinhibition rebound excitatory output to the musculature. This is strongly influenced by vagal efferent motor neurons and this in turn is influenced by vagal afferent neurons that send bolus information to the solitary nucleus where programmed activation of the vagal motor neurons to the smooth muscle esophagus is initiated. Solitary nucleus activity is influenced by sensory activity from a large number of organs and various areas of the brain, including the hypothalamus and the cerebral cortex. This allows interaction between swallowing activities and respiratory and cardiac activities and allows the influence of acute and chronic emotional states on swallowing behavior. Interstitial cells of Cajal are part of the sensory units of vagal afferents, the intramuscular arrays, and they provide pacemaker activity to the musculature that can generate peristalsis in the absence of innervation. This indicates that a low-amplitude esophageal contraction, observed as IEM, can be caused by a multitude of factors, and therefore many pathways can be potentially explored to restore normal esophageal peristalsis.
Collapse
Affiliation(s)
- Ji-Hong Chen
- Department of Gastroenterology, Renmin Hospital, Wuhan University, Wuhan, People's Republic of China; Division of Gastroenterology, Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada
| |
Collapse
|
36
|
Spencer NJ, Kyloh M, Beckett EA, Brookes S, Hibberd T. Different types of spinal afferent nerve endings in stomach and esophagus identified by anterograde tracing from dorsal root ganglia. J Comp Neurol 2016; 524:3064-83. [DOI: 10.1002/cne.24006] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 03/21/2016] [Accepted: 03/24/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Nick J. Spencer
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University; Adelaide 5001 South Australia Australia
| | - Melinda Kyloh
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University; Adelaide 5001 South Australia Australia
| | - Elizabeth A Beckett
- Discipline of Physiology, School of Medicine, University of Adelaide; Adelaide 5000 South Australia Australia
| | - Simon Brookes
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University; Adelaide 5001 South Australia Australia
| | - Tim Hibberd
- Discipline of Human Physiology and Centre for Neuroscience, School of Medicine, Flinders University; Adelaide 5001 South Australia Australia
| |
Collapse
|