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Spencer NJ, Kyloh MA, Travis L, Hibberd TJ. Identification of vagal afferent nerve endings in the mouse colon and their spatial relationship with enterochromaffin cells. Cell Tissue Res 2024; 396:313-327. [PMID: 38383905 PMCID: PMC11144134 DOI: 10.1007/s00441-024-03879-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/13/2024] [Indexed: 02/23/2024]
Abstract
Understanding how the gut communicates with the brain, via sensory nerves, is of significant interest to medical science. Enteroendocrine cells (EEC) that line the mucosa of the gastrointestinal tract release neurochemicals, including the largest quantity of 5-hydroxytryptamine (5-HT). How the release of substances, like 5-HT, from enterochromaffin (EC) cells activates vagal afferent nerve endings is unresolved. We performed anterograde labelling from nodose ganglia in vivo and identified vagal afferent axons and nerve endings in the mucosa of whole-mount full-length preparations of mouse colon. We then determined the spatial relationship between mucosal-projecting vagal afferent nerve endings and EC cells in situ using 3D imaging. The mean distances between vagal afferent nerve endings in the mucosa, or nearest varicosities along vagal afferent axon branches, and the nearest EC cell were 29.6 ± 19.2 μm (n = 107, N = 6) and 25.7 ± 15.2 μm (n = 119, N = 6), respectively. No vagal afferent endings made close contacts with EC cells. The distances between EC cells and vagal afferent endings are many hundreds of times greater than known distances between pre- and post-synaptic membranes (typically 10-20 nm) that underlie synaptic transmission in vertebrates. The absence of any close physical contacts between 5-HT-containing EC cells and vagal afferent nerve endings in the mucosa leads to the inescapable conclusion that the mechanism by which 5-HT release from ECs in the colonic mucosa occurs in a paracrine fashion, to activate vagal afferents.
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Affiliation(s)
- Nick J Spencer
- Visceral Neurophysiology Laboratory, Flinders Health and Medical Research Institute & College of Medicine and Public Health, Flinders University of South Australia, GPO Box 2100, Bedford Park, Adelaide, South Australia, 5042, Australia.
| | - Melinda A Kyloh
- Visceral Neurophysiology Laboratory, Flinders Health and Medical Research Institute & College of Medicine and Public Health, Flinders University of South Australia, GPO Box 2100, Bedford Park, Adelaide, South Australia, 5042, Australia
| | - Lee Travis
- Visceral Neurophysiology Laboratory, Flinders Health and Medical Research Institute & College of Medicine and Public Health, Flinders University of South Australia, GPO Box 2100, Bedford Park, Adelaide, South Australia, 5042, Australia
| | - Timothy J Hibberd
- Visceral Neurophysiology Laboratory, Flinders Health and Medical Research Institute & College of Medicine and Public Health, Flinders University of South Australia, GPO Box 2100, Bedford Park, Adelaide, South Australia, 5042, Australia
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2
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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.
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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.
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Neuhuber WL, Berthoud HR. Functional anatomy of the vagus system - Emphasis on the somato-visceral interface. Auton Neurosci 2021; 236:102887. [PMID: 34634680 DOI: 10.1016/j.autneu.2021.102887] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 09/02/2021] [Accepted: 09/21/2021] [Indexed: 11/18/2022]
Abstract
Due to its pivotal role in autonomic networks, the vagus attracts continuous interest from both basic scientists and clinicians. In particular, recent advances in vagus nerve stimulation strategies and their application to pathological conditions beyond epilepsy provide a good opportunity to recall basic features of vagal peripheral and central anatomy. In addition to the "classical" vagal brainstem nuclei, i.e., dorsal motor nucleus, nucleus ambiguus and nucleus tractus solitarii, the spinal trigeminal and paratrigeminal nuclei come into play as targets of vagal afferents. On the other hand, the nucleus of the solitary tract receives and integrates not only visceral but also somatic afferents. Thus, the vagus system participates significantly in what may be defined as "somato-visceral interface".
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Affiliation(s)
- Winfried L Neuhuber
- Institute of Anatomy and Cell Biology, Friedrich-Alexander University, Krankenhausstrasse 9, Erlangen, Germany.
| | - Hans-Rudolf Berthoud
- Neurobiology of Nutrition & Metabolism Department, Pennington Biomedical Research Center, Louisiana State University, 6400 Perkins Road, Baton Rouge, LA 70808, USA.
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4
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Computational evaluation of laparoscopic sleeve gastrectomy. Updates Surg 2021; 73:2253-2262. [PMID: 33817769 PMCID: PMC8606391 DOI: 10.1007/s13304-021-01046-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/29/2021] [Indexed: 12/12/2022]
Abstract
LSG is one of the most performed bariatric procedures worldwide. It is a safe and effective operation with a low complication rate. Unsatisfactory weight loss/regain may occur, suggesting that the operation design could be improved. A bioengineering approach might significantly help in avoiding the most common complications. Computational models of the sleeved stomach after LSG were developed according to bougie size (range 27-54 Fr). The endoluminal pressure and the basal volume were computed at different intragastric pressures. At an inner pressure of 22.5 mmHg, the basal volume of the 54 Fr configuration was approximately 6 times greater than that of the 27 Fr configuration (57.92 ml vs 9.70 ml). Moreover, the elongation distribution of the gastric wall was assessed to quantify the effect on mechanoreceptors impacting satiety by differencing regions and layers. An increasing trend in elongation strain with increasing bougie size was observed in all cases. The most stressed region and layer were the antrum (approximately 25% higher stress than that in the corpus at 37.5 mmHg) and mucosa layer (approximately 7% higher stress than that in the muscularis layer at 22.5 mmHg), respectively. In addition, the pressure-volume behaviors were reported. Computational models and bioengineering methods can help to quantitatively identify some critical aspects of the "design" of bariatric operations to plan interventions, and predict and increase the success rate. Moreover, computational tools can support the development of innovative bariatric procedures, potentially skipping invasive approaches.
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Kapitza C, Chunder R, Scheller A, Given KS, Macklin WB, Enders M, Kuerten S, Neuhuber WL, Wörl J. Murine Esophagus Expresses Glial-Derived Central Nervous System Antigens. Int J Mol Sci 2021; 22:ijms22063233. [PMID: 33810144 PMCID: PMC8004938 DOI: 10.3390/ijms22063233] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/14/2021] [Accepted: 03/16/2021] [Indexed: 12/27/2022] Open
Abstract
Multiple sclerosis (MS) has been considered to specifically affect the central nervous system (CNS) for a long time. As autonomic dysfunction including dysphagia can occur as accompanying phenomena in patients, the enteric nervous system has been attracting increasing attention over the past years. The aim of this study was to identify glial and myelin markers as potential target structures for autoimmune processes in the esophagus. RT-PCR analysis revealed glial fibrillary acidic protein (GFAP), proteolipid protein (PLP), and myelin basic protein (MBP) expression, but an absence of myelin oligodendrocyte glycoprotein (MOG) in the murine esophagus. Selected immunohistochemistry for GFAP, PLP, and MBP including transgenic mice with cell-type specific expression of PLP and GFAP supported these results by detection of (1) GFAP, PLP, and MBP in Schwann cells in skeletal muscle and esophagus; (2) GFAP, PLP, but no MBP in perisynaptic Schwann cells of skeletal and esophageal motor endplates; (3) GFAP and PLP, but no MBP in glial cells surrounding esophageal myenteric neurons; and (4) PLP, but no GFAP and MBP in enteric glial cells forming a network in the esophagus. Our results pave the way for further investigations regarding the involvement of esophageal glial cells in the pathogenesis of dysphagia in MS.
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Affiliation(s)
- Christopher Kapitza
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (C.K.); (R.C.); (M.E.); (S.K.); (W.L.N.)
| | - Rittika Chunder
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (C.K.); (R.C.); (M.E.); (S.K.); (W.L.N.)
| | - Anja Scheller
- University of Saarland, Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), 66421 Homburg, Germany;
| | - Katherine S. Given
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA; (K.S.G.); (W.B.M.)
| | - Wendy B. Macklin
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA; (K.S.G.); (W.B.M.)
| | - Michael Enders
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (C.K.); (R.C.); (M.E.); (S.K.); (W.L.N.)
| | - Stefanie Kuerten
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (C.K.); (R.C.); (M.E.); (S.K.); (W.L.N.)
- Department of Neuroanatomy, Institute of Anatomy, University Hospitals Bonn, University Bonn, 53115 Bonn, Germany
| | - Winfried L. Neuhuber
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (C.K.); (R.C.); (M.E.); (S.K.); (W.L.N.)
| | - Jürgen Wörl
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany; (C.K.); (R.C.); (M.E.); (S.K.); (W.L.N.)
- Correspondence: ; Tel.: +49-913-1852-2870
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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.
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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
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Johnson AC, Louwies T, Ligon CO, Greenwood-Van Meerveld B. Enlightening the frontiers of neurogastroenterology through optogenetics. Am J Physiol Gastrointest Liver Physiol 2020; 319:G391-G399. [PMID: 32755304 PMCID: PMC7717115 DOI: 10.1152/ajpgi.00384.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Neurogastroenterology refers to the study of the extrinsic and intrinsic nervous system circuits controlling the gastrointestinal (GI) tract. Over the past 5-10 yr there has been an explosion in novel methodologies, technologies and approaches that offer great promise to advance our understanding of the basic mechanisms underlying GI function in health and disease. This review focuses on the use of optogenetics combined with electrophysiology in the field of neurogastroenterology. We discuss how these technologies and tools are currently being used to explore the brain-gut axis and debate the future research potential and limitations of these techniques. Taken together, we consider that the use of these technologies will enable researchers to answer important questions in neurogastroenterology through fundamental research. The answers to those questions will shorten the path from basic discovery to new treatments for patient populations with disorders of the brain-gut axis affecting the GI tract such as irritable bowel syndrome (IBS), functional dyspepsia, achalasia, and delayed gastric emptying.
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Affiliation(s)
- Anthony C. Johnson
- 1Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma,2Oklahoma City Veterans Affairs Health Care System, Oklahoma City, Oklahoma,3Department of Neurology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Tijs Louwies
- 1Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Casey O. Ligon
- 1Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Beverley Greenwood-Van Meerveld
- 1Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma,2Oklahoma City Veterans Affairs Health Care System, Oklahoma City, Oklahoma,4Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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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.
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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
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9
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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.
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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
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Harsanyiova J, Ru F, Zatko T, Kollarik M, Hennel M. Vagus Nerves Provide a Robust Afferent Innervation of the Mucosa Throughout the Body of the Esophagus in the Mouse. Dysphagia 2020; 35:471-478. [PMID: 31468191 PMCID: PMC10688604 DOI: 10.1007/s00455-019-10051-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 08/12/2019] [Indexed: 12/12/2022]
Abstract
The vagal afferent nerves regulate swallowing and esophageal motor reflexes. However, there are still gaps in the understanding of vagal afferent innervation of the esophageal mucosa. Anatomical studies found that the vagal afferent mucosal innervation is dense in the upper esophageal sphincter area but rare in more distal segments of the esophagus. In contrast, electrophysiological studies concluded that the vagal afferent nerve fibers also densely innervate mucosa in more distal esophagus. We hypothesized that the transfection of vagal afferent neurons with adeno-associated virus vector encoding green fluorescent protein (AAV-GFP) allows to visualize vagal afferent nerve fibers in the esophageal mucosa in the mouse. AAV-GFP was injected into the vagal jugular/nodose ganglia in vivo to sparsely label vagal afferent nerve fibers. The esophageal tissue was harvested 4-6 weeks later, the GFP signal was amplified by immunostaining, and confocal optical sections of the entire esophagi were obtained. We found numerous GFP-labeled fibers in the mucosa throughout the whole body of the esophagus. The GFP-labeled mucosal fibers were located just beneath the epithelium, branched repeatedly, had mostly longitudinal orientation, and terminated abruptly without forming terminal structures. The GFP-labeled mucosal fibers were concentrated in random areas of various sizes in which many fibers could be traced to a single parental axon. We conclude that the vagus nerves provide a robust afferent innervation of the mucosa throughout the whole body of the esophagus in the mouse. Vagal mucosal fibers may contribute to the sensing of intraluminal content and regulation of swallowing and other reflexes.
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Affiliation(s)
- J Harsanyiova
- Department of Pathophysiology, Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Mala Hora 4C, 036 01, Martin, Slovakia
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd, MDC 8, Tampa, FL, 33612, USA
| | - F Ru
- Department of Medicine, Allergy and Asthma Center, The Johns Hopkins University School of Medicine, 5501 Hopkins Bayview Circle, Baltimore, MD, 21224, USA
| | - T Zatko
- Department of Pathophysiology, Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Mala Hora 4C, 036 01, Martin, Slovakia
| | - M Kollarik
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd, MDC 8, Tampa, FL, 33612, USA
| | - M Hennel
- Division of Neuroscience, Biomedical Center Martin, Comenius University in Bratislava, Jessenius Faculty of Medicine in Martin (JFM CU), Malá Hora 4C, 036 01, Martin, Slovakia.
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11
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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.
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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.
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Aktar R, Peiris M, Fikree A, Eaton S, Kritas S, Kentish SJ, Araujo EJA, Bacarin C, Page AJ, Voermans NC, Aziz Q, Blackshaw LA. A novel role for the extracellular matrix glycoprotein-Tenascin-X in gastric function. J Physiol 2019; 597:1503-1515. [PMID: 30605228 PMCID: PMC6418764 DOI: 10.1113/jp277195] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 12/19/2018] [Indexed: 01/27/2023] Open
Abstract
KEY POINTS Tenascin X (TNX) functions in the extracellular matrix of skin and joints where it maintains correct intercellular connections and tissue architecture TNX is associated exclusively with vagal-afferent endings and some myenteric neurones in mouse and human stomach, respectively. TNX-deficient mice have accelerated gastric emptying and hypersensitivity of gastric vagal mechanoreceptors that can be normalized by an inhibitor of vagal-afferent sensitivity. Cultured nodose ganglion neurones showed no changes in response to capsaicin, cholecystokinin and potassium chloride in TNX-deficient mice. TNX-deficient patients have upper gastric dysfunction consistent with those in a mouse model. Our translational studies suggest that abnormal gastric sensory function may explain the upper gut symptoms present in TNX deficient patients, thus making it important to study gastric physiology. TNX deficiency should be evaluated routinely in patients with connective tissue abnormalities, which will enable a better understanding of its role and allow targeted treatment. For example, inhibitors of vagal afferents-baclofen could be beneficial in patients. These hypotheses need confirmation via targeted clinical trials. ABSTRACT Tenascin-X (TNX) is a glycoprotein that regulates tissue structure via anti-adhesive interactions with collagen in the extracellular matrix. TNX deficiency causes a phenotype similar to hypermobility Ehlers-Danlos syndrome involving joint hypermobility, skin hyperelasticity, pain and gastrointestinal dysfunction. Previously, we have shown that TNX is required for neural control of the bowel by a specific subtype of mainly cholinergic enteric neurones and regulates sprouting and sensitivity of nociceptive sensory endings in mouse colon. These findings correlate with symptoms shown by TNX-deficient patients and mice. We aimed to identify whether TNX is similarly present in neural structures found in mouse and human gastric tissue. We then determined whether TNX has a functional role, specifically in gastric motor and sensory function and nodose ganglia neurones. We report that TNX was present in calretinin-immunoreactive extrinsic nerve endings in mouse and human stomach. TNX deficient mice had accelerated gastric emptying and markedly increased vagal afferent responses to gastric distension that could be rescued with GABAB receptor agonist. There were no changes in nodose ganglia excitability in TNX deficient mice, suggesting that vagal afferent responses are probably the result of altered peripheral mechanosensitivity. In TNXB-deficient patients, significantly greater symptoms of reflux, indigestion and abdominal pain were reported. In the present study, we report the first role for TNX in gastric function. Further studies are required in TNX deficient patients to determine whether symptoms can be relieved using GABAB agonists.
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Affiliation(s)
- Rubina Aktar
- Blizard InstituteQueen Mary University of LondonLondonUK
| | - Madusha Peiris
- Blizard InstituteQueen Mary University of LondonLondonUK
| | - Asma Fikree
- Blizard InstituteQueen Mary University of LondonLondonUK
| | - Simon Eaton
- Institute of Child HealthUniversity College LondonLondonUK
| | - Stamatiki Kritas
- South Australian Health and Medical Research InstituteUniversity of AdelaideAustralia
| | - Stephen J. Kentish
- South Australian Health and Medical Research InstituteUniversity of AdelaideAustralia
| | - Eduardo J. A. Araujo
- Blizard InstituteQueen Mary University of LondonLondonUK
- Department of HistologyCentre for Biological SciencesState University of LondrinaBrazil
| | - Cristiano Bacarin
- Department of HistologyCentre for Biological SciencesState University of LondrinaBrazil
| | - Amanda J. Page
- South Australian Health and Medical Research InstituteUniversity of AdelaideAustralia
| | - Nicol C. Voermans
- Department of NeurologyRadboud University Medical CentreNijmegenNetherlands
| | - Qasim Aziz
- Blizard InstituteQueen Mary University of LondonLondonUK
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Brierley SM, Hibberd TJ, Spencer NJ. Spinal Afferent Innervation of the Colon and Rectum. Front Cell Neurosci 2018; 12:467. [PMID: 30564102 PMCID: PMC6288476 DOI: 10.3389/fncel.2018.00467] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 11/16/2018] [Indexed: 12/12/2022] Open
Abstract
Despite their seemingly elementary roles, the colon and rectum undertake a variety of key processes to ensure our overall wellbeing. Such processes are coordinated by the transmission of sensory signals from the periphery to the central nervous system, allowing communication from the gut to the brain via the "gut-brain axis". These signals are transmitted from the peripheral terminals of extrinsic sensory nerve fibers, located within the wall of the colon or rectum, and via their axons within the spinal splanchnic and pelvic nerves to the spinal cord. Recent studies utilizing electrophysiological, anatomical and gene expression techniques indicate a surprisingly diverse set of distinct afferent subclasses, which innervate all layers of the colon and rectum. Combined these afferent sub-types allow the detection of luminal contents, low- and high-intensity stretch or contraction, in addition to the detection of inflammatory, immune, and microbial mediators. To add further complexity, the proportions of these afferents vary within splanchnic and pelvic pathways, whilst the density of the splanchnic and pelvic innervation also varies along the colon and rectum. In this review we traverse this complicated landscape to elucidate afferent function, structure, and nomenclature to provide insights into how the extrinsic sensory afferent innervation of the colon and rectum gives rise to physiological defecatory reflexes and sensations of discomfort, bloating, urgency, and pain.
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Affiliation(s)
- Stuart M Brierley
- Visceral Pain Research Group, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia.,Centre for Nutrition and Gastrointestinal Diseases, Discipline of Medicine, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide, Adelaide, SA, Australia
| | - Timothy J Hibberd
- Visceral Neurophysiology Laboratory, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Nick J Spencer
- Visceral Neurophysiology Laboratory, Centre for Neuroscience, College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
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Visceral pain - Novel approaches for optogenetic control of spinal afferents. Brain Res 2018; 1693:159-164. [PMID: 29425907 DOI: 10.1016/j.brainres.2018.02.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/22/2018] [Accepted: 02/01/2018] [Indexed: 11/21/2022]
Abstract
Painful stimuli arising within visceral organs are detected by peripheral nerve endings of spinal afferents, whose cell bodies are located in dorsal root ganglia (DRG). Recent technical advances have made it possible to reliably expose and inject single DRG with neuronal tracers or viruses in vivo. This has facilitated, for the first time, unequivocal identification of different types of spinal afferent endings in visceral organs. These technical advances paved the way for a very exciting series of in vivo experiments where individual DRG are injected to facilitate opsin expression (e.g. Archaerhodopsin). Organ-specific expression of opsins in sensory neurons may be achieved by retrograde viral transduction. This means activity of target-specific populations of sensory neurons, within single DRG, can be modulated by optogenetic photo-stimulation. Using this approach we implanted micro light-emitting diodes (micro-LEDs) adjacent to DRG of interest, thereby allowing focal DRG-specific control of visceral and/or somatic afferents in conscious mice. This is vastly different from broad photo-illumination of peripheral nerve endings, which are dispersed over much larger surface areas across an entire visceral organ; and embedded deep within multiple anatomical layers. Focal DRG photo-stimulation also avoids the potential that wide-field illumination of the periphery could inadvertently activate other closely apposed organs, or co-activate different classes of axons in the same organ (e.g. enteric and spinal afferent endings in the gut). It is now possible to selectively control nociceptive and/or non-nociceptive pathways to specific visceral organs in vivo, using wireless optogenetics and micro-LEDs implanted adjacent to DRG, for targeted photo-stimulation.
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Kamitakahara A, Wu HH, Levitt P. Distinct projection targets define subpopulations of mouse brainstem vagal neurons that express the autism-associated MET receptor tyrosine kinase. J Comp Neurol 2017; 525:3787-3808. [PMID: 28758209 DOI: 10.1002/cne.24294] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 07/14/2017] [Accepted: 07/17/2017] [Indexed: 12/11/2022]
Abstract
Detailed anatomical tracing and mapping of the viscerotopic organization of the vagal motor nuclei has provided insight into autonomic function in health and disease. To further define specific cellular identities, we paired information based on visceral connectivity with a cell-type specific marker of a subpopulation of neurons in the dorsal motor nucleus of the vagus (DMV) and nucleus ambiguus (nAmb) that express the autism-associated MET receptor tyrosine kinase. As gastrointestinal disturbances are common in children with autism spectrum disorder (ASD), we sought to define the relationship between MET-expressing (MET+) neurons in the DMV and nAmb, and the gastrointestinal tract. Using wholemount tissue staining and clearing, or retrograde tracing in a METEGFP transgenic mouse, we identify three novel subpopulations of EGFP+ vagal brainstem neurons: (a) EGFP+ neurons in the nAmb projecting to the esophagus or laryngeal muscles, (b) EGFP+ neurons in the medial DMV projecting to the stomach, and (b) EGFP+ neurons in the lateral DMV projecting to the cecum and/or proximal colon. Expression of the MET ligand, hepatocyte growth factor (HGF), by tissues innervated by vagal motor neurons during fetal development reveal potential sites of HGF-MET interaction. Furthermore, similar cellular expression patterns of MET in the brainstem of both the mouse and nonhuman primate suggests that MET expression at these sites is evolutionarily conserved. Together, the data suggest that MET+ neurons in the brainstem vagal motor nuclei are anatomically positioned to regulate distinct portions of the gastrointestinal tract, with implications for the pathophysiology of gastrointestinal comorbidities of ASD.
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Affiliation(s)
- Anna Kamitakahara
- Program in Developmental Neurogenetics, Institute for the Developing Mind, The Saban Resarch Institute, Children's Hospital Los Angeles, Los Angeles, California
| | - Hsiao-Huei Wu
- Keck School of Medicine of University of Southern California, Los Angeles, California
| | - Pat Levitt
- Program in Developmental Neurogenetics, Institute for the Developing Mind, The Saban Resarch Institute, Children's Hospital Los Angeles, Los Angeles, California.,Department of Pediatrics, Keck School of Medicine of University of Southern California, Los Angeles, California.,University of Southern California Program in Neuroscience, Los Angeles, California
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16
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Chen Z, Liu L, Tu J, Qin G, Su W, Geng X, Chen X, Wu H, Pan W. Improvement of atropine on esophagogastric junction observation during sedative esophagogastroduodenoscopy. PLoS One 2017; 12:e0179490. [PMID: 28654639 PMCID: PMC5487030 DOI: 10.1371/journal.pone.0179490] [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: 12/04/2016] [Accepted: 05/31/2017] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND AND STUDY AIMS Although sedation esophagogastroduodenoscopy (EGD) is now widely used, previous research has reported that sedation during EGD exhibits a negative effect on esophagogastric junction (EGJ) exposure. Atropine might improve EGJ exposure, as noted in clinical practice. The aim of this study was to examine whether sedation had a negative effect on EGJ observation in the Chinese population, and whether atropine had some ability to act as an antidote to this unexpected secondary effect of sedation. PATIENTS AND METHODS In this cross-sectional study, subjects were divided into the following three groups according to the methods of EGD examination: the non-sedation group, the propofol-fentanyl combined sedation group and the combined sedation with atropine administration group. The EGJ observation was assessed by a key photograph taken with the endoscopic camera 1 cm from the EGJ, which was rated on the following four-degree scale: excellent (score = 4), good (score = 3), fair (score = 2) and poor (score = 1). RESULTS The EGJ exposure was better in the sedation group administered atropine (score = 2.64±1.05) than in the sedation group (score = 1.99±1.08, P<0.05) but not as good as in the non-sedation group (score = 3.24±1.12, P<0.05). Reduced detection of EGJ diseases in the sedation group was also found, compared to the non-sedation group (P<0.05). Only the use of atropine (OR = 2.381, 95%CI: 1.297-4.371, P = 0.005) was independently associated with excellent observation of the EGJ during sedation EGD. CONCLUSIONS Combined propofol-fentanyl sedation reduces the extent of exposure of the EGJ during EGD and reduces the detection of EGJ diseases. The application of atropine in the sedation endoscopy examination helped to achieve better EGJ observation, but still cannot achieve an equal extent of exposure compared to non-sedation EGD.
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Affiliation(s)
- Zhihao Chen
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Lingang Liu
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Department of Gastroenterology, Longsai Hospital, Ningbo, China
| | - Jiangfeng Tu
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Department of Gastroenterology, Zhejiang Provincial People’s Hospital, Hangzhou, China
| | - Guangming Qin
- Department of Laboratory, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Weiwei Su
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaoge Geng
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaojun Chen
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Hongguang Wu
- Department of Gastroenterology, Quzhou Second People's Hospital, Quzhou, China
| | - Wensheng Pan
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Department of Gastroenterology, Zhejiang Provincial People’s Hospital, Hangzhou, China
- * E-mail:
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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.
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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
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18
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Jhuo SJ, Lo LW, Chang SL, Lin YJ, Chung FP, Chiou CW, Chen SA. Periesophageal vagal plexus injury is a favorable outcome predictor after catheter ablation of atrial fibrillation. Heart Rhythm 2016; 13:1786-93. [PMID: 27236026 DOI: 10.1016/j.hrthm.2016.05.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Indexed: 12/24/2022]
Abstract
BACKGROUND Collateral damage to periesophageal vagal plexus associated with symptomatic gastric hypomotility and associated symptoms are not uncommon after catheter ablation of atrial fibrillation (AF). The injury may indicate transmural ablation lesions. OBJECTIVE The purpose of this study was to evaluate the periesophageal vagal plexus injury (PNI) and long-term outcome after catheter ablation of AF. METHODS A total of 441 consecutive patients with AF (mean age 54.71 ± 10.52 years; 134 women) who underwent catheter ablation (paroxysmal AF, n = 312; persistent AF, n = 129) were retrospectively enrolled from 2011 to 2013; group 1 was defined as patients with PNI and associated symptoms (n = 88), and group 2 was defined as patients without PNI or associated symptoms (n = 353). Baseline characteristics and electrophysiological properties were collected to analyze the relationship between PNI and clinical outcome. The association of AF recurrence after catheter ablation and PNI symptoms was also investigated. RESULTS During a mean follow-up period of 37.3 ± 0.94 months, group 1 had longer AF-freedom days in sinus rhythm after AF ablation and had less recurrence after the blanking period compared with group 2 (mean recurrence days, 1254.22 ± 45.26 days vs 1065.21 ± 33.35 days; P < .01). Multivariate analysis also revealed that PNI was an independently protective predictor of AF recurrence (hazard ratio 0.527; 95% confidence interval 0.289-0.959; P = .036). There was no difference in baseline characteristics, CHA2DS2-VASc score, or echocardiography follow-up duration. CONCLUSION PNI and associated symptoms are not uncommon after catheter ablation of AF. A better long-term outcome is thereby independently predicted, suggesting transmural ablation lesions during pulmonary vein isolation.
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Affiliation(s)
- Shih-Jie Jhuo
- Division of Cardiology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan; Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Li-Wei Lo
- Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, College of Medicine, National Yang-Ming Medical University, Taipei, Taiwan
| | - Shih-Lin Chang
- Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, College of Medicine, National Yang-Ming Medical University, Taipei, Taiwan
| | - Yenn-Jiang Lin
- Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, College of Medicine, National Yang-Ming Medical University, Taipei, Taiwan
| | - Fa-Po Chung
- Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chuen-Wang Chiou
- Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, College of Medicine, National Yang-Ming Medical University, Taipei, Taiwan
| | - Shih-Ann Chen
- Division of Cardiology, Taipei Veterans General Hospital, Taipei, Taiwan; Faculty of Medicine, College of Medicine, National Yang-Ming Medical University, Taipei, Taiwan.
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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
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20
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Walter GC, Phillips RJ, McAdams JL, Powley TL. Individual sympathetic postganglionic neurons coinnervate myenteric ganglia and smooth muscle layers in the gastrointestinal tract of the rat. J Comp Neurol 2016; 524:2577-603. [PMID: 26850701 DOI: 10.1002/cne.23978] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 01/21/2016] [Accepted: 02/02/2016] [Indexed: 01/25/2023]
Abstract
A full description of the terminal architecture of sympathetic axons innervating the gastrointestinal (GI) tract has not been available. To label sympathetic fibers projecting to the gut muscle wall, dextran biotin was injected into the celiac and superior mesenteric ganglia (CSMG) of rats. Nine days postinjection, animals were euthanized and stomachs and small intestines were processed as whole mounts (submucosa and mucosa removed) to examine CSMG efferent terminals. Myenteric neurons were counterstained with Cuprolinic Blue; catecholaminergic axons were stained immunohistochemically for tyrosine hydroxylase. Essentially all dextran-labeled axons (135 of 136 sampled) were tyrosine hydroxylase-positive. Complete postganglionic arbors (n = 154) in the muscle wall were digitized and analyzed morphometrically. Individual sympathetic axons formed complex arbors of varicose neurites within myenteric ganglia/primary plexus and, concomitantly, long rectilinear arrays of neurites within circular muscle/secondary plexus or longitudinal muscle/tertiary plexus. Very few CSMG neurons projected exclusively (i.e., ∼100% of an arbor's varicose branches) to myenteric plexus (∼2%) or smooth muscle (∼14%). With less stringent inclusion criteria (i.e., ≥85% of an axon's varicose branches), larger minorities of neurons projected predominantly to either myenteric plexus (∼13%) or smooth muscle (∼27%). The majority (i.e., ∼60%) of all individual CSMG postganglionics formed mixed, heterotypic arbors that coinnervated extensively (>15% of their varicose branches per target) both myenteric ganglia and smooth muscle. The fact that ∼87% of all sympathetics projected either extensively or even predominantly to smooth muscle, while simultaneously contacting myenteric plexus, is consistent with the view that these neurons control GI muscle directly, if not exclusively. J. Comp. Neurol. 524:2577-2603, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Gary C Walter
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Robert J Phillips
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Jennifer L McAdams
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Terry L Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, USA
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21
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Rytel L, Calka J. Acetylsalicylic acid-induced changes in the chemical coding of extrinsic sensory neurons supplying the prepyloric area of the porcine stomach. Neurosci Lett 2016; 617:218-24. [PMID: 26917098 DOI: 10.1016/j.neulet.2016.02.029] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 02/11/2016] [Accepted: 02/16/2016] [Indexed: 12/22/2022]
Abstract
Acetylsalicylic acid is a popular drug that is commonly used to treat fever and inflammation, but which can also negativity affect the mucosal layer of the stomach, although knowledge concerning its influence on gastric innervation is very scarce. Thus, the aim of the present study was to study the influence of prolonged acetylsalicylic acid supplementation on the extrinsic primary sensory neurons supplying the porcine stomach prepyloric region. Fast Blue (FB) was injected into the above-mentioned region of the stomach. Acetylsalicylic acid was then given orally to the experimental gilts from the seventh day after FB injection to the 27th day of the experiment. After euthanasia, the nodose ganglia (NG) and dorsal root ganglia (DRG) were collected. Sections of these ganglia were processed for routine double-labelling immunofluorescence technique for substance P (SP), calcitonine gene related peptide (CGRP), galanin (GAL), neuronal isoform of nitric oxide synthase (nNOS) and vasoactive intestinal polypeptide (VIP). Under physiological conditions within the nodose ganglia, the percentage of the FB-labeled neurons immunoreactive to particular substances ranged between 17.9 ± 2.7% (VIP-like immunoreactive (LI) neurons in the right NG) and 60.4 ± 1.7% (SP-LI cells within the left NG). Acetylsalicylic acid supplementation caused a considerable increase in the expression of all active substances studied within both left and right NG and the percentage of neurons positive to particular substances fluctuated from 47.2 ± 3.6% (GAL-LI neurons in the right NG) to 67.2 ± 2.0% (cells immunoreactive to SP in the left NG). All studied substances were also observed in DRG neurons supplying the prepyloric region of the stomach, but the number of immunoreactive neurons was too small to conduct a statistical analysis. The obtained results show that ASA may influence chemical coding of the sensory neurons supplying the porcine stomach, but the exact mechanisms of this action still remain unknown.
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Affiliation(s)
- L Rytel
- Department of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Str. Oczapowski 13, Olsztyn, Poland.
| | - J Calka
- Department of Clinical Physiology, Faculty of Veterinary Medicine, University of Warmia and Mazury, Str. Oczapowski 13, Olsztyn, Poland
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Powley TL, Hudson CN, McAdams JL, Baronowsky EA, Phillips RJ. Vagal Intramuscular Arrays: The Specialized Mechanoreceptor Arbors That Innervate the Smooth Muscle Layers of the Stomach Examined in the Rat. J Comp Neurol 2015; 524:713-37. [PMID: 26355387 DOI: 10.1002/cne.23892] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/18/2015] [Accepted: 08/19/2015] [Indexed: 01/14/2023]
Abstract
The fundamental roles that the stomach plays in ingestion and digestion notwithstanding, little morphological information is available on vagal intramuscular arrays (IMAs), the afferents that innervate gastric smooth muscle. To characterize IMAs better, rats were given injections of dextran biotin in the nodose ganglia, and, after tracer transport, stomach whole mounts were collected. Specimens were processed for avidin-biotin permanent labeling, and subsets of the whole mounts were immunohistochemically processed for c-Kit or stained with cuprolinic blue. IMAs (n = 184) were digitized for morphometry and mapping. Throughout the gastric muscle wall, IMAs possessed common phenotypic features. Each IMA was generated by a parent neurite arborizing extensively, forming an array of multiple (mean = 212) branches averaging 193 µm in length. These branches paralleled, and coursed in apposition with, bundles of muscle fibers and interstitial cells of Cajal. Individual arrays averaged 4.3 mm in length and innervated volumes of muscle sheet, presumptive receptive fields, averaging 0.1 mm(3) . Evaluated by region and by muscle sheet, IMAs displayed architectural adaptations to the different loci. A subset (32%) of circular muscle IMAs issued specialized polymorphic collaterals to myenteric ganglia, and a subset (41%) of antral longitudinal muscle IMAs formed specialized net endings associated with the serosal boundary. IMAs were concentrated in regional patterns that correlated with the unique biomechanical adaptations of the stomach, specifically proximal stomach reservoir functions and antral emptying operations. Overall, the structural adaptations and distributions of the IMAs were consonant with the hypothesized stretch receptor roles of the afferents.
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Affiliation(s)
- Terry L Powley
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, 47907-2081
| | - Cherie N Hudson
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, 47907-2081
| | - Jennifer L McAdams
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, 47907-2081
| | - Elizabeth A Baronowsky
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, 47907-2081
| | - Robert J Phillips
- Department of Psychological Sciences, Purdue University, West Lafayette, Indiana, 47907-2081
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Calik MW, Radulovacki M, Carley DW. A method of nodose ganglia injection in Sprague-Dawley rat. J Vis Exp 2014:e52233. [PMID: 25490160 DOI: 10.3791/52233] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Afferent signaling via the vagus nerve transmits important general visceral information to the central nervous system from many diverse receptors located in the organs of the abdomen and thorax. The vagus nerve communicates information from stimuli such as heart rate, blood pressure, bronchopulmonary irritation, and gastrointestinal distension to the nucleus of solitary tract of the medulla. The cell bodies of the vagus nerve are located in the nodose and petrosal ganglia, of which the majority are located in the former. The nodose ganglia contain a wealth of receptors for amino acids, monoamines, neuropeptides, and other neurochemicals that can modify afferent vagus nerve activity. Modifying vagal afferents through systemic peripheral drug treatments targeted at the receptors on nodose ganglia has the potential of treating diseases such as sleep apnea, gastroesophageal reflux disease, or chronic cough. The protocol here describes a method of injection neurochemicals directly into the nodose ganglion. Injecting neurochemicals directly into the nodose ganglia allows study of effects solely on cell bodies that modulate afferent nerve activity, and prevents the complication of involving the central nervous system as seen in systemic neurochemical treatment. Using readily available and inexpensive equipment, intranodose ganglia injections are easily done in anesthetized Sprague-Dawley rats.
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Affiliation(s)
- Michael W Calik
- Center for Narcolepsy, Sleep and Health Research, University of Illinois at Chicago; Department of Biobehavioral Health Science, University of Illinois at Chicago;
| | - Miodrag Radulovacki
- Center for Narcolepsy, Sleep and Health Research, University of Illinois at Chicago; Department of Pharmacology, University of Illinois at Chicago
| | - David W Carley
- Center for Narcolepsy, Sleep and Health Research, University of Illinois at Chicago; Department of Biobehavioral Health Science, University of Illinois at Chicago
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Powley TL, Hudson CN, McAdams JL, Baronowsky EA, Martin FN, Mason JK, Phillips RJ. Organization of vagal afferents in pylorus: mechanoreceptors arrayed for high sensitivity and fine spatial resolution? Auton Neurosci 2014; 183:36-48. [PMID: 24656895 DOI: 10.1016/j.autneu.2014.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 02/24/2014] [Accepted: 02/26/2014] [Indexed: 01/16/2023]
Abstract
The pylorus is innervated by vagal mechanoreceptors that project to gastrointestinal smooth muscle, but the distributions and specializations of vagal endings in the sphincter have not been fully characterized. To evaluate their organization, the neural tracer dextran biotin was injected into the nodose ganglia of rats. Following tracer transport, animals were perfused, and their pylori and antra were prepared as whole mounts. Specimens were processed to permanently label the tracer, and subsets were counterstained with Cuprolinic blue or immunostained for c-Kit. Intramuscular arrays (IMAs) in the circular muscle comprised the principal vagal afferent innervation of the sphincter. These pyloric ring IMAs were densely distributed and evidenced a variety of structural specializations. Morphometric comparisons between the arbors innervating the pylorus and a corresponding sample of IMAs in the adjacent antral circular muscle highlighted that sphincter IMAs branched profusely, forming more than twice as many branches as did antral IMAs (means of 405 vs. 165, respectively), and condensed their numerous neurites into compact receptive fields (∼48% of the area of antral IMAs) deep in the circular muscle (∼6μm above the submucosa). Separate arbors of IMAs in the sphincter interdigitated and overlapped to form a 360° band of mechanoreceptors encircling the pyloric canal. The annulus of vagal IMA arbors, putative stretch receptors tightly intercalated in the sphincter ring and situated near the lumen of the pyloric canal, creates an architecture with the potential to generate gut reflexes on the basis of pyloric sensory maps of high sensitivity and fine spatial resolution.
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Affiliation(s)
- Terry L Powley
- Purdue University, Department of Psychological Sciences, West Lafayette, IN 47907-2081, United States.
| | - Cherie N Hudson
- Purdue University, Department of Psychological Sciences, West Lafayette, IN 47907-2081, United States
| | - Jennifer L McAdams
- Purdue University, Department of Psychological Sciences, West Lafayette, IN 47907-2081, United States
| | - Elizabeth A Baronowsky
- Purdue University, Department of Psychological Sciences, West Lafayette, IN 47907-2081, United States
| | - Felecia N Martin
- Purdue University, Department of Psychological Sciences, West Lafayette, IN 47907-2081, United States
| | - Jacqueline K Mason
- Purdue University, Department of Psychological Sciences, West Lafayette, IN 47907-2081, United States
| | - Robert J Phillips
- Purdue University, Department of Psychological Sciences, West Lafayette, IN 47907-2081, United States.
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Kyloh M, Spencer NJ. A novel anterograde neuronal tracing technique to selectively label spinal afferent nerve endings that encode noxious and innocuous stimuli in visceral organs. Neurogastroenterol Motil 2014; 26:440-4. [PMID: 24460783 DOI: 10.1111/nmo.12266] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 11/04/2013] [Indexed: 02/08/2023]
Abstract
BACKGROUND One major weakness in our understanding of pain perception from visceral organs is the lack of knowledge of the location, morphology and neurochemistry of all the different types of spinal afferent nerve endings, which detect noxious and innocuous stimuli. This is because we lack techniques to selectively label only spinal afferents. Our aim was to develop an anterograde tracing technique that labels only spinal afferent nerve endings in visceral organs, without also labeling all other classes of extrinsic afferent and efferent nerves. METHODS Mice were anesthetized with isoflurane and dextran-biotin injected, via glass micropipettes (diameter 5 μm), into L6 and S1 dorsal root ganglia. Mice recovered for 7 days, were then euthanized and the colon removed. KEY RESULTS Anterograde labeling revealed multiple unique classes of afferent endings that terminated within distinct anatomical layers of the colon and rectum. We characterized a particular class of intramuscular ending in the circular muscle (CM) layer of the colon that consists of multiple varicose axons that project circumferentially. CONCLUSIONS & INFERENCES We demonstrate a technique for selective anterograde labeling of spinal afferent nerve endings in visceral organs. This approach facilitates selective visualization of the precise morphology and location of the different classes of spinal afferent endings, without visual interference caused by indiscriminant labeling of other classes of afferent and efferent nerve axons which also innervate internal organs. We have used this new technique to identify and describe the details of a particular class of intramuscular spinal afferent ending in the CM layer of mouse large intestine.
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Affiliation(s)
- M Kyloh
- Discipline of Human Physiology and Centre for Neuroscience, Flinders University of South Australia, Adelaide, South Australia, Australia
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Architecture of vagal motor units controlling striated muscle of esophagus: peripheral elements patterning peristalsis? Auton Neurosci 2013; 179:90-8. [PMID: 24044976 DOI: 10.1016/j.autneu.2013.08.069] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 08/22/2013] [Accepted: 08/24/2013] [Indexed: 11/22/2022]
Abstract
Little is known about the architecture of the vagal motor units that control esophageal striated muscle, in spite of the fact that these units are necessary, and responsible, for peristalsis. The present experiment was designed to characterize the motor neuron projection fields and terminal arbors forming esophageal motor units. Nucleus ambiguus compact formation neurons of the rat were labeled by bilateral intracranial injections of the anterograde tracer dextran biotin. After tracer transport, thoracic and abdominal esophagi were removed and prepared as whole mounts of muscle wall without mucosa or submucosa. Labeled terminal arbors of individual vagal motor neurons (n=78) in the esophageal wall were inventoried, digitized and analyzed morphometrically. The size of individual vagal motor units innervating striated muscle, throughout thoracic and abdominal esophagus, averaged 52 endplates per motor neuron, a value indicative of fine motor control. A majority (77%) of the motor terminal arbors also issued one or more collateral branches that contacted neurons, including nitric oxide synthase-positive neurons, of local myenteric ganglia. Individual motor neuron terminal arbors co-innervated, or supplied endplates in tandem to, both longitudinal and circular muscle fibers in roughly similar proportions (i.e., two endplates to longitudinal for every three endplates to circular fibers). Both the observation that vagal motor unit collaterals project to myenteric ganglia and the fact that individual motor units co-innervate longitudinal and circular muscle layers are consistent with the hypothesis that elements contributing to peristaltic programming inhere, or are "hardwired," in the peripheral architecture of esophageal motor units.
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