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Kuramoto H, Yabe M, Morishita R, Yoshimura R, Sakamoto H. Localization of sensory nerve terminals containing calcitonin gene-related peptide (CGRP) on striated muscle fibers in the rat esophagus: Evidence for triple innervation via motor endplates. Auton Neurosci 2024; 253:103177. [PMID: 38636284 DOI: 10.1016/j.autneu.2024.103177] [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: 12/21/2023] [Revised: 02/26/2024] [Accepted: 04/11/2024] [Indexed: 04/20/2024]
Abstract
BACKGROUND Many esophageal striated muscles of mammals are dually innervated by the vagal and enteric nerves. Recently, substance P (SP)-sensory nerve terminals with calcitonin gene-related peptide (CGRP) were found on a few striated muscle fibers in the rat esophagus, implying that these muscle fibers are triply innervated. In this study, we examined the localization and origin of CGRP-nerve endings in striated muscles to consider their possible roles in the esophagus regarding triple innervation. METHODS Wholemounts of the rat esophagus were immunolabeled to detect CGRP-nerve endings in striated muscles. Also, retrograde tracing was performed by injecting Fast Blue (FB) into the esophagus, and cryostat sections of the medulla oblongata, nodose ganglion (NG), and the tenth thoracic (T10) dorsal root ganglion (DRG) were immunostained to identify the origin of the CGRP-nerve endings. RESULTS CGRP-fine, varicose nerve endings were localized in motor endplates on a few esophageal striated muscle fibers (4 %), most of which received nitric oxide (NO) synthase nerve terminals, and most of the CGRP nerve endings were SP- and transient receptor potential vanilloid member 1 (TRPV1)-positive. Retrograde tracing showed many FB-labeled CGRP-neurons positive for SP and TRPV1 in the NG and T10 DGR. CONCLUSIONS This study suggests that the CGRP-varicose nerve endings containing SP and TRPV1 in motor endplates are sensory, and a few esophageal striated muscle fibers are triply innervated. The nerve endings may detect acetylcholine-derived acetic acid from the vagal motor nerve endings and NO from esophageal intrinsic nerve terminals in the motor endplates to regulate esophageal motility.
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Affiliation(s)
- Hirofumi Kuramoto
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan.
| | - Mana Yabe
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Ryo Morishita
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Ryoichi Yoshimura
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Hiroshi Sakamoto
- Department of Physical Therapy, Health Science University, Yamanashi 401-0380, Japan
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Shiina T, Suzuki Y, Horii K, Sawamura T, Yuki N, Horii Y, Shimizu Y. Purinergic inhibitory regulation of esophageal smooth muscle is mediated by P2Y receptors and ATP-dependent potassium channels in rats. J Physiol Sci 2024; 74:26. [PMID: 38654149 PMCID: PMC11036717 DOI: 10.1186/s12576-024-00916-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 03/20/2024] [Indexed: 04/25/2024]
Abstract
Purines such as ATP are regulatory transmitters in motility of the gastrointestinal tract. The aims of this study were to propose functional roles of purinergic regulation of esophageal motility. An isolated segment of the rat esophagus was placed in an organ bath, and mechanical responses were recorded using a force transducer. Exogenous application of ATP (10-100 μM) evoked relaxation of the esophageal smooth muscle in a longitudinal direction under the condition of carbachol (1 μM) -induced precontraction. Pretreatment with a non-selective P2 receptor antagonist, suramin (500 μM), and a P2Y receptor antagonist, cibacron blue F3GA (200 μM), inhibited the ATP (100 μM) -induced relaxation, but a P2X receptor antagonist, pyridoxal phosphate-6-azophenyl-2,4-disulfonic acid (50 μM), did not affect it. A blocker of ATP-dependent potassium channels (KATP channels), glibenclamide (200 μM), inhibited the ATP-induced relaxation and application of an opener of KATP channels, nicorandil (50 μM), produced relaxation. The findings suggest that ATP is involved in inhibitory regulation of the longitudinal smooth muscle in the muscularis mucosae of the rat esophagus via activation of P2Y receptors and then opening of KATP channels.
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Affiliation(s)
- Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan.
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan.
| | - Yuji Suzuki
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Kazuhiro Horii
- Division of Biological Principles, Department of Physiology, Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Tomoya Sawamura
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Natsufu Yuki
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Yuuki Horii
- Institute for Glyco-Core Research (iGCORE), Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
- Division of Animal Medical Science, Center for One Medicine Innovative Translational Research (COMIT), Gifu University Institute for Advanced Study, 1-1 Yanagido, Gifu, 501-1193, Japan
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3
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Suzuki Y, Shimizu Y, Shiina T. ATP-Induced Contractile Response of Esophageal Smooth Muscle in Mice. Int J Mol Sci 2024; 25:1985. [PMID: 38396664 PMCID: PMC10888660 DOI: 10.3390/ijms25041985] [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: 12/19/2023] [Revised: 01/31/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024] Open
Abstract
The tunica muscularis of mammalian esophagi is composed of striated muscle and smooth muscle. Contraction of the esophageal striated muscle portion is mainly controlled by cholinergic neurons. On the other hand, smooth muscle contraction and relaxation are controlled not only by cholinergic components but also by non-cholinergic components in the esophagus. Adenosine triphosphate (ATP) is known to regulate smooth muscle contraction and relaxation in the gastrointestinal tract via purinergic receptors. However, the precise mechanism of purinergic regulation in the esophagus is still unclear. Therefore, the aim of the present study was to clarify the effects of ATP on the mechanical responses of the esophageal muscle in mice. An isolated segment of the mouse esophagus was placed in a Magnus's tube and longitudinal mechanical responses were recorded. Exogenous application of ATP induced contractile responses in the esophageal preparations. Tetrodotoxin, a blocker of voltage-dependent sodium channels in neurons and striated muscle, did not affect the ATP-induced contraction. The ATP-evoked contraction was blocked by pretreatment with suramin, a purinergic receptor antagonist. RT-PCR revealed the expression of mRNA of purinergic receptor genes in the mouse esophageal tissue. The findings suggest that purinergic signaling might regulate the motor activity of mouse esophageal smooth muscle.
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Grants
- 2021 Koshiyama Science & Technology foundation
- 2021 OGAWA Science and Technology Foundation
- 17K08122 Grants-in-Aid for Scientific Research (KAKENHI) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan
- 20K06409 Grants-in-Aid for Scientific Research (KAKENHI) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan
- 23K05553 Grants-in-Aid for Scientific Research (KAKENHI) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan
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Affiliation(s)
- Yuji Suzuki
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan (Y.S.)
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan (Y.S.)
- Division of Animal Medical Science, Center for One Medicine Innovative Translational Research (COMIT), Gifu University Institute for Advanced Study, 1-1 Yanagido, Gifu 501-1193, Japan
| | - Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan (Y.S.)
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4
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Sharkey KA, Mawe GM. The enteric nervous system. Physiol Rev 2023; 103:1487-1564. [PMID: 36521049 PMCID: PMC9970663 DOI: 10.1152/physrev.00018.2022] [Citation(s) in RCA: 51] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 12/12/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Of all the organ systems in the body, the gastrointestinal tract is the most complicated in terms of the numbers of structures involved, each with different functions, and the numbers and types of signaling molecules utilized. The digestion of food and absorption of nutrients, electrolytes, and water occurs in a hostile luminal environment that contains a large and diverse microbiota. At the core of regulatory control of the digestive and defensive functions of the gastrointestinal tract is the enteric nervous system (ENS), a complex system of neurons and glia in the gut wall. In this review, we discuss 1) the intrinsic neural control of gut functions involved in digestion and 2) how the ENS interacts with the immune system, gut microbiota, and epithelium to maintain mucosal defense and barrier function. We highlight developments that have revolutionized our understanding of the physiology and pathophysiology of enteric neural control. These include a new understanding of the molecular architecture of the ENS, the organization and function of enteric motor circuits, and the roles of enteric glia. We explore the transduction of luminal stimuli by enteroendocrine cells, the regulation of intestinal barrier function by enteric neurons and glia, local immune control by the ENS, and the role of the gut microbiota in regulating the structure and function of the ENS. Multifunctional enteric neurons work together with enteric glial cells, macrophages, interstitial cells, and enteroendocrine cells integrating an array of signals to initiate outputs that are precisely regulated in space and time to control digestion and intestinal homeostasis.
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Affiliation(s)
- Keith A Sharkey
- Hotchkiss Brain Institute and Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Gary M Mawe
- Department of Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington, Vermont
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5
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Morishita R, Yoshimura R, Sakamoto H, Kuramoto H. Localization of substance P (SP)-immunoreactivity in the myenteric plexus of the rat esophagus. Histochem Cell Biol 2023; 159:7-21. [PMID: 35507035 DOI: 10.1007/s00418-022-02104-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/03/2022] [Indexed: 02/07/2023]
Abstract
The present immunohistochemical study was performed to examine the number, distribution, and chemical coding of intrinsic substance P (SP) neurons and nerve fibers within the esophagus and discuss their functional roles. Many SP neurons and nerve fibers were found in the myenteric plexus, and the SP neurons gradually decreased from the oral side toward the aboral side of the esophagus. Double-immunolabeling showed that most SP neurons were cholinergic (positive for choline acetyltransferase), and few were nitrergic (positive for nitric oxide synthase). Some cholinergic SP nerve terminals surrounded cell bodies of several myenteric neurons. In the muscularis mucosa and lower esophageal sphincter, and around blood vessels, numerous SP nerve endings were present, and many of them were cholinergic. Also, SP nerve endings were found on only a few motor endplates of the striated muscles, and most of them were calcitonin gene-related peptide (CGRP)-positive. Retrograde tracing using Fast Blue (FB) showed that numerous sensory neurons in the dorsal root ganglia (DRGs) and nodose ganglion (NG) projected to the esophagus, and most FB-labeled SP neurons were CGRP-positive. These results suggest that the intrinsic SP neurons in the rat esophagus may play roles as, at least, motor neurons, interneurons, and vasomotor neurons, which are involved in local regulation of smooth muscle motility, neuronal transmission, and blood circulation, respectively. Moreover, SP nerve endings on only a minority of motor endplates may be extrinsic, derived from DRGs or NG, and possibly detect chemical circumstances within motor endplates to modulate esophageal motility.
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Affiliation(s)
- Ryo Morishita
- Cell Function Division, Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
| | - Ryoichi Yoshimura
- Cell Function Division, Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
| | - Hiroshi Sakamoto
- Department of Physical Therapy, Health Science University, Yamanashi, Japan
| | - Hirofumi Kuramoto
- Cell Function Division, Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan.
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6
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Zinsser-Krys J, Kapitza C, Böhnke L, van der Keylen P, Neuhuber WL, Wörl J. Neurochemical classification of serotonin-immunoreactive neurons co-innervating motor endplates in the mouse esophagus. Anat Rec (Hoboken) 2022; 306:960-971. [PMID: 35838072 DOI: 10.1002/ar.25030] [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: 02/28/2022] [Revised: 05/11/2022] [Accepted: 06/06/2022] [Indexed: 11/08/2022]
Abstract
Serotonin immunoreactivity was previously found in myenteric neurons co-innervating motor endplates in the mouse esophagus striated muscle and an involvement in motility control was suggested. However, it is not known if other neuroactive substances are present in these neurons and to what extent they co-localize. First, vasoactive intestinal peptide (VIP) was established as a bona fide marker for putative inhibitory myenteric neurons by evaluating co-localization with neuronal nitric oxide synthase (nNOS) and neuropeptide Y (NPY). Then, co-localization of serotonin and VIP was tested in co-innervating axons on motor endplates, which were visualized with α-bungarotoxin (α-BT) by multilabel immunofluorescence. Myenteric ganglia were also surveyed for co-localization in neuronal perikarya and varicosities. nNOS, NPY, and VIP were completely co-localized in enteric co-innervating nerve terminals on motor endplates. After co-staining with VIP, we found (a) serotonin (5-HT)-positive nerve endings without VIP (44% of 5-HT-positively innervated endplates), (b) 5-HT- and VIP-positive endings without co-localization (35%), and (c) 5-HT- and VIP-positive endings with co-localization (21%). About one-fifth of nerve terminals on motor endplates containing 5-HT originate from putative inhibitory peptidegic nitrergic neurons. However, the majority represents a different population presumably subserving different functions.
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Affiliation(s)
- Jillena Zinsser-Krys
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Christopher Kapitza
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Lena Böhnke
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Piet van der Keylen
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Winfried L Neuhuber
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jürgen Wörl
- Institute of Anatomy and Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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7
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Goluba K, Kunrade L, Riekstina U, Parfejevs V. Schwann Cells in Digestive System Disorders. Cells 2022; 11:832. [PMID: 35269454 PMCID: PMC8908985 DOI: 10.3390/cells11050832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 11/18/2022] Open
Abstract
Proper functioning of the digestive system is ensured by coordinated action of the central and peripheral nervous systems (PNS). Peripheral innervation of the digestive system can be viewed as intrinsic and extrinsic. The intrinsic portion is mainly composed of the neurons and glia of the enteric nervous system (ENS), while the extrinsic part is formed by sympathetic, parasympathetic, and sensory branches of the PNS. Glial cells are a crucial component of digestive tract innervation, and a great deal of research evidence highlights the important status of ENS glia in health and disease. In this review, we shift the focus a bit and discuss the functions of Schwann cells (SCs), the glial cells of the extrinsic innervation of the digestive system. For more context, we also provide information on the basic findings regarding the function of innervation in disorders of the digestive organs. We find diverse SC roles described particularly in the mouth, the pancreas, and the intestine. We note that most of the scientific evidence concerns the involvement of SCs in cancer progression and pain, but some research identifies stem cell functions and potential for regenerative medicine.
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Affiliation(s)
| | | | | | - Vadims Parfejevs
- Faculty of Medicine, University of Latvia, House of Science, Jelgavas Str. 3, LV-1004 Riga, Latvia; (K.G.); (L.K.); (U.R.)
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8
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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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9
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Structural and Functional Synaptic Plasticity Induced by Convergent Synapse Loss in the Drosophila Neuromuscular Circuit. J Neurosci 2021; 41:1401-1417. [PMID: 33402422 DOI: 10.1523/jneurosci.1492-20.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 11/28/2020] [Accepted: 12/17/2020] [Indexed: 12/22/2022] Open
Abstract
Throughout the nervous system, the convergence of two or more presynaptic inputs on a target cell is commonly observed. The question we ask here is to what extent converging inputs influence each other's structural and functional synaptic plasticity. In complex circuits, isolating individual inputs is difficult because postsynaptic cells can receive thousands of inputs. An ideal model to address this question is the Drosophila larval neuromuscular junction (NMJ) where each postsynaptic muscle cell receives inputs from two glutamatergic types of motor neurons (MNs), known as 1b and 1s MNs. Notably, each muscle is unique and receives input from a different combination of 1b and 1s MNs; we surveyed multiple muscles for this reason. Here, we identified a cell-specific promoter that allows ablation of 1s MNs postinnervation and measured structural and functional responses of convergent 1b NMJs using microscopy and electrophysiology. For all muscles examined in both sexes, ablation of 1s MNs resulted in NMJ expansion and increased spontaneous neurotransmitter release at corresponding 1b NMJs. This demonstrates that 1b NMJs can compensate for the loss of convergent 1s MNs. However, only a subset of 1b NMJs showed compensatory evoked neurotransmission, suggesting target-specific plasticity. Silencing 1s MNs led to similar plasticity at 1b NMJs, suggesting that evoked neurotransmission from 1s MNs contributes to 1b synaptic plasticity. Finally, we genetically blocked 1s innervation in male larvae and robust 1b synaptic plasticity was eliminated, raising the possibility that 1s NMJ formation is required to set up a reference for subsequent synaptic perturbations.SIGNIFICANCE STATEMENT In complex neural circuits, multiple convergent inputs contribute to the activity of the target cell, but whether synaptic plasticity exists among these inputs has not been thoroughly explored. In this study, we examined synaptic plasticity in the structurally and functionally tractable Drosophila larval neuromuscular system. In this convergent circuit, each muscle is innervated by a unique pair of motor neurons. Removal of one neuron after innervation causes the adjacent neuron to increase neuromuscular junction outgrowth and functional output. However, this is not a general feature as each motor neuron differentially compensates. Further, robust compensation requires initial coinnervation by both neurons. Understanding how neurons respond to perturbations in adjacent neurons will provide insight into nervous system plasticity in both healthy and disease states.
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Nikaki K, Sawada A, Ustaoglu A, Sifrim D. Neuronal Control of Esophageal Peristalsis and Its Role in Esophageal Disease. Curr Gastroenterol Rep 2019; 21:59. [PMID: 31760496 DOI: 10.1007/s11894-019-0728-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
PURPOSE OF REVIEW Esophageal peristalsis is a highly sophisticated function that involves the coordinated contraction and relaxation of striated and smooth muscles in a cephalocaudal fashion, under the control of central and peripheral neuronal mechanisms and a number of neurotransmitters. Esophageal peristalsis is determined by the balance of the intrinsic excitatory cholinergic, inhibitory nitrergic and post-inhibitory rebound excitatory output to the esophageal musculature. RECENT FINDINGS Dissociation of the longitudinal and circular muscle contractions characterizes different major esophageal disorders and leads to esophageal symptoms. Provocative testing during esophageal high-resolution manometry is commonly employed to assess esophageal body peristaltic reserve and underpin clinical diagnosis. Herein, we summarize the main factors that determine esophageal peristalsis and examine their role in major and minor esophageal motility disorders and eosinophilic esophagitis.
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Affiliation(s)
- K Nikaki
- Wingate Institute of Neurogastroenterology, Blizard Institute, Barts and The London School of Medicine and Dentistry, QMUL, 26 Ashfield Street, Whitechapel, London, E1 2AJ, UK
| | - A Sawada
- Wingate Institute of Neurogastroenterology, Blizard Institute, Barts and The London School of Medicine and Dentistry, QMUL, 26 Ashfield Street, Whitechapel, London, E1 2AJ, UK
| | - A Ustaoglu
- Wingate Institute of Neurogastroenterology, Blizard Institute, Barts and The London School of Medicine and Dentistry, QMUL, 26 Ashfield Street, Whitechapel, London, E1 2AJ, UK
| | - D Sifrim
- Wingate Institute of Neurogastroenterology, Blizard Institute, Barts and The London School of Medicine and Dentistry, QMUL, 26 Ashfield Street, Whitechapel, London, E1 2AJ, UK.
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11
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Horii K, Suzuki Y, Shiina T, Saito S, Onouchi S, Horii Y, Shimaoka H, Shimizu Y. ATP-dependent potassium channels contribute to motor regulation of esophageal striated muscle in rats. J Vet Med Sci 2019; 81:1266-1272. [PMID: 31292350 PMCID: PMC6785617 DOI: 10.1292/jvms.19-0197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of the present study was to clarify roles of ATP-dependent potassium channels (KATP channels) in motility of the striated muscle portion in the esophagus. An isolated segment of the rat esophagus was placed in an organ bath and mechanical responses were recorded using a force transducer. Electrical stimulation of the vagus nerve evoked contractile response of striated muscle in the esophageal segment. Application of glibenclamide, an antagonist of KATP channels, increased amplitude of vagally mediated twitch contractions of the rat esophagus. On the other hand, minoxidil, an agonist of KATP channels, decreased amplitude of twitch contractions. RT-PCR revealed the expression of subunits of KATP channels in esophageal tissue. In addition, immunopositivity for subunits of KATP channels was observed in the striated muscle cells of the esophageal muscle layer. These findings indicate that KATP channels contribute to motor regulation of striated muscle in the rat esophagus.
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Affiliation(s)
- Kazuhiro Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagaido, Gifu 501-1193, Japan
| | - Yuji Suzuki
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagaido, Gifu 501-1193, Japan
| | - Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagaido, Gifu 501-1193, Japan
| | - Shouichiro Saito
- Department of Basic Veterinary Science, Laboratory of Anatomy, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagaido, Gifu 501-1193, Japan
| | - Sawa Onouchi
- Department of Basic Veterinary Science, Laboratory of Anatomy, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagaido, Gifu 501-1193, Japan
| | - Yuuki Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagaido, Gifu 501-1193, Japan
| | - Hiroki Shimaoka
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagaido, Gifu 501-1193, Japan
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagaido, Gifu 501-1193, Japan.,Center for Highly Advanced Integration of Nano and Life Sciences (G-CHAIN), Gifu University, 1-1 Yanagaido, Gifu 501-1193, Japan
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Horii K, Shiina T, Naitou K, Nakamori H, Horii Y, Shimaoka H, Shimizu Y. Characterization of peristaltic motility in the striated muscle portion of the esophagus using a novel in vivo method in rats. Neurogastroenterol Motil 2019; 31:e13518. [PMID: 30549155 DOI: 10.1111/nmo.13518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/23/2018] [Accepted: 10/29/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND Esophageal peristalsis is controlled by the brainstem via vago-vagal reflex. However, the precise regulatory mechanisms in the striated muscle portion are largely unknown. The aim of this study was to characterize peristaltic motility in the portion of the esophagus using a novel in vivo method in rats. METHODS A balloon-tipped catheter was placed in the esophagus of a rat anesthetized with urethane. To induce esophageal peristalsis, the balloon was inflated by water injection. KEY RESULTS When the balloon was inflated near the bronchial bifurcation, the balloon was transported in the aboral direction. Vagotomy abolished the peristaltic response. The threshold volume for inducing esophageal peristalsis varied according to the velocity of balloon distention; the volume being effective to induce peristalsis at a low inflation speed was smaller than the threshold volume at a rapid inflation speed. Even in the absence of inflation, keeping the balloon inside the esophagus during an interval period prevented subsequent induction of peristaltic motility. In addition, a nitric oxide synthase inhibitor abolished the induction of esophageal peristalsis. CONCLUSIONS AND INFERENCES Our findings suggest that (a) in addition to the intensity, the velocity of distention is important for activating the mechanosensory mechanism to induce esophageal peristalsis, (b) tonic inputs from afferent fibers located at the mucosa may reduce the excitability of mechanosensors which is necessary for inducing peristalsis, and (c) nitric oxide plays essential roles in the induction of esophageal peristalsis. These results provide novel insights into the regulatory mechanisms of esophageal motility.
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Affiliation(s)
- Kazuhiro Horii
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Takahiko Shiina
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Kiyotada Naitou
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Hiroyuki Nakamori
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Yuuki Horii
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Hiroki Shimaoka
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Yasutake Shimizu
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.,Center for Highly Advanced Integration of Nano and Life Sciences (G-CHAIN), Gifu University, Gifu, Japan
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Kuramoto H, Yoshimura R, Sakamoto H, Kadowaki M. Regional variations in the number distribution of intrinsic myenteric neurons and coinnervated motor endplates on the striated muscles in the rat esophagus. Auton Neurosci 2019; 219:25-32. [PMID: 31122598 DOI: 10.1016/j.autneu.2019.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 03/19/2019] [Accepted: 03/20/2019] [Indexed: 01/05/2023]
Abstract
The roles of intrinsic neurons and the significance of the coinnervated striated muscles in the esophagus are unclear. We examined the number distribution of intrinsic neurons and coinnervated motor endplates on the striated muscles in the rat esophagus using immunohistochemistry to investigate whether these neurons and coinnervated striated muscles may be relevant to the local control of esophageal motility. The number of PGP9.5-positive neurons was higher in the cervical esophagus (segment 1) and gradually decreased toward the aboral, with a moderate increase in the abdominal (segment 5). This pattern was similar to that of NOS-positive neurons, while the number of ChAT-positive neurons decreased toward the aboral, but it was not significantly different among segments 3 to 5. The number of ChAT-positive motor endplates increased toward the aboral, with the highest number in segment 5. The proportion of coinnervated motor endplates was approximately 80% in segments 1 to 4, but approximately 66% in segment 5. NPY-IR was localized in some nerve terminals among the smooth muscles of the muscularis mucosa and some NOS- or ChAT-positive esophageal intrinsic neurons. ENK-8-IR was found in some NOS- or ChAT-positive intrinsic neurons, and nerve terminals surrounding intrinsic neurons in the esophagus, but not in motor neurons at the NA or DMV. This study suggests that regional variations in the number of intrinsic neurons and coinnervated striated muscles in the rat esophagus may be involved in local regulations of esophageal motility, and that the rat esophageal intrinsic neurons may contain, at least, motor neurons and interneurons.
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Affiliation(s)
- Hirofumi Kuramoto
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan.
| | - Ryoichi Yoshimura
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
| | - Hiroshi Sakamoto
- Department of Physical Therapy, Health Science University, Yamanashi, Japan
| | - Makoto Kadowaki
- Division of Gastrointestinal Pathophysiology, Institute of Natural Medicine, University of Toyama, Toyama, Japan
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Zimmermann J, Neuhuber WL, Raab M. Homer1 (VesL-1) in the rat esophagus: focus on myenteric plexus and neuromuscular junction. Histochem Cell Biol 2017; 148:189-206. [PMID: 28337539 DOI: 10.1007/s00418-017-1555-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2017] [Indexed: 12/20/2022]
Abstract
Homer1, a scaffolding protein of the postsynaptic density (PSD), enriched at excitatory synapses is known to anchor and modulate group I metabotropic glutamate receptors (mGluRs) and different channel- and receptor-proteins. Homer proteins are expressed in neurons of different brain regions, but also in non-neuronal tissues like skeletal muscle. Occurrence and location of Homer1 and mGluR5 in myenteric plexus and neuromuscular junctions (NMJ) of rat esophagus have yet not been characterized. We located Homer1 and mGluR5 immunoreactivity (-iry) in rat esophagus and focused on myenteric neurons, intraganglionic laminar endings (IGLEs) and NMJs, using double- and triple-label immunohistochemistry and confocal laser scanning microscopy. Homer1-iry was found in a subpopulation of vesicular glutamate transporter 2 (VGLUT2) positive IGLEs and cholinergic varicosities within myenteric ganglia, but neither in nitrergic nor cholinergic myenteric neuronal cell bodies. Homer1-iry was detected in 63% of esophageal and, for comparison, in 35% of sternomastoid NMJs. Besides the location in the PSD, Homer1-iry colocalized with cholinergic markers, indicating a presynaptic location in coarse VAChT/CGRP/NF200- immunoreactive (-ir) terminals of nucleus ambiguus neurons supplying striated esophageal muscle. mGluR5-iry was found in subpopulations of myenteric neuronal cell bodies, VGLUT2-ir IGLEs and cholinergic varicosities within the myenteric neuropil and NMJs of esophagus and sternomastoid muscles. Thus, Homer1 may anchor mGluR5 at presynaptic sites of cholinergic boutons at esophageal motor endplates, in a small subpopulation of VGLUT2-ir IGLEs and cholinergic varicosities within myenteric ganglia possibly modulating Ca2+-currents and neurotransmitter release.
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Affiliation(s)
- J Zimmermann
- Institut für Anatomie, Lehrstuhl I, Friedrich-Alexander-Universität, Krankenhausstr. 9, 91054, Erlangen, Germany
| | - W L Neuhuber
- Institut für Anatomie, Lehrstuhl I, Friedrich-Alexander-Universität, Krankenhausstr. 9, 91054, Erlangen, Germany
| | - M Raab
- Institut für Anatomie, Lehrstuhl I, Friedrich-Alexander-Universität, Krankenhausstr. 9, 91054, Erlangen, Germany.
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In focus in HCB: from cell biology to tissue structure and function. Histochem Cell Biol 2016; 146:645-646. [PMID: 27796529 DOI: 10.1007/s00418-016-1511-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2016] [Indexed: 10/20/2022]
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