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Liang YF, Chen XQ, Zhang MT, Tang HY, Shen GM. Research Progress of Central and Peripheral Corticotropin-Releasing Hormone in Irritable Bowel Syndrome with Comorbid Dysthymic Disorders. Gut Liver 2024; 18:391-403. [PMID: 37551453 PMCID: PMC11096901 DOI: 10.5009/gnl220346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 04/26/2023] [Accepted: 05/22/2023] [Indexed: 08/09/2023] Open
Abstract
Irritable bowel syndrome (IBS) is considered a stress disorder characterized by psychological and gastrointestinal dysfunction. IBS patients not only suffer from intestinal symptoms such as abdominal pain, diarrhea, or constipation but also, experience dysthymic disorders such as anxiety and depression. Studies have found that corticotropin-releasing hormone plays a key role in IBS with comorbid dysthymic disorders. Next, we will summarize the effects of corticotropin-releasing hormone from the central nervous system and periphery on IBS with comorbid dysthymic disorders and relevant treatments based on published literatures in recent years.
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Affiliation(s)
- Yi Feng Liang
- College of Acupuncture and Massage, Anhui University of Chinese Medicine, Hefei, China
| | - Xiao Qi Chen
- College of Acupuncture and Massage, Anhui University of Chinese Medicine, Hefei, China
| | - Meng Ting Zhang
- College of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - He Yong Tang
- College of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, China
| | - Guo Ming Shen
- College of Integrated Chinese and Western Medicine, Anhui University of Chinese Medicine, Hefei, China
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Sawamura T, Yuki N, Aoki K, Horii K, Horii Y, Naitou K, Tsukamoto S, Shiina T, Shimizu Y. Alterations in descending brain-spinal pathways regulating colorectal motility in a rat model of Parkinson's disease. Am J Physiol Gastrointest Liver Physiol 2024; 326:G195-G204. [PMID: 38111988 DOI: 10.1152/ajpgi.00181.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/13/2023] [Accepted: 12/17/2023] [Indexed: 12/20/2023]
Abstract
Patients with Parkinson's disease (PD) often have constipation. It is assumed that a disorder of the regulatory mechanism of colorectal motility by the central nervous system is involved in the constipation, but this remains unclear. The aim of this study was to investigate whether central neural pathways can modulate colorectal motility in a rat model of PD. PD model rats were generated by injection of 6-hydroxydopamine into a unilateral medial forebrain bundle and destruction of dopaminergic neurons in the substantia nigra. Colorectal motility was measured in vivo in anesthetized rats. Intraluminal administration of capsaicin, as a noxious stimulus, induced colorectal motility in sham-operated rats but not in PD rats. Intrathecally administered dopamine (DA) and serotonin (5-HT), which mediate the prokinetic effect of capsaicin, at the L6-S1 levels enhanced colorectal motility in PD rats similarly to that in sham-operated rats. In PD rats, capsaicin enhanced colorectal motility only when a GABAA receptor antagonist was preadministered into the lumbosacral spinal cord. Capsaicin-induced colorectal motility was abolished by intrathecal administration of a D2-like receptor antagonist but not by administration of 5-HT2 and 5-HT3 receptor antagonists. These findings demonstrate that the inhibitory GABAergic component becomes operative and the stimulatory serotonergic component is suppressed in PD rats. The alteration of the central regulatory mechanism of colorectal motility is thought to be related to the occurrence of constipation in PD patients. Our findings provide a new insight into the pathogenesis of defecation disorders observed in PD.NEW & NOTEWORTHY In a rat model of Parkinson's disease, the component of descending brain-spinal pathways that regulate colorectal motility through a mediation of the lumbosacral defecation center was altered from stimulatory serotonergic neurons to inhibitory GABAergic neurons. Our findings suggest that chronic constipation in Parkinson's disease patients may be associated with alterations in central regulatory mechanisms of colorectal motility. The plasticity in the descending pathway regulating colorectal motility may contribute to other disease-related defecation abnormalities.
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Affiliation(s)
- Tomoya Sawamura
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Natsufu Yuki
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Kanae Aoki
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Kazuhiro Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
- Division of Biological Principles, Department of Physiology, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Yuuki Horii
- Institute for Glyco-core Research (iGCORE), Gifu University, Gifu, Japan
| | - Kiyotada Naitou
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Shumpei Tsukamoto
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
- Department of Basic Veterinary Science, Laboratory of Physiology, Joint Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
- Division of Animal Medical Science, Center for One Medicine Innovative Translational Research (COMIT), Gifu University Institute for Advanced Study, Gifu, Japan
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Wang Q, Caraballo SG, Rychkov G, McGovern AE, Mazzone SB, Brierley SM, Harrington AM. Comparative localization of colorectal sensory afferent central projections in the mouse spinal cord dorsal horn and caudal medulla dorsal vagal complex. J Comp Neurol 2024; 532:e25546. [PMID: 37837642 DOI: 10.1002/cne.25546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 09/04/2023] [Accepted: 10/03/2023] [Indexed: 10/16/2023]
Abstract
The distal colon and rectum (colorectum) are innervated by spinal and vagal afferent pathways. The central circuits into which vagal and spinal afferents relay colorectal nociceptive information remain to be comparatively assessed. To address this, regional colorectal retrograde tracing and colorectal distension (CRD)-evoked neuronal activation were used to compare the circuits within the dorsal vagal complex (DVC) and dorsal horn (thoracolumbar [TL] and lumbosacral [LS] spinal levels) into which vagal and spinal colorectal afferents project. Vagal afferent projections were observed in the nucleus tractus solitarius (NTS), area postrema (AP), and dorsal motor nucleus of the vagus (DMV), labeled from the rostral colorectum. In the NTS, projections were opposed to catecholamine and pontine parabrachial nuclei (PbN)-projecting neurons. Spinal afferent projections were labeled from rostral through to caudal aspects of the colorectum. In the dorsal horn, the number of neurons activated by CRD was linked to pressure intensity, unlike in the DVC. In the NTS, 13% ± 0.6% of CRD-activated neurons projected to the PbN. In the dorsal horn, at the TL spinal level, afferent input was associated with PbN-projecting neurons in lamina I (LI), with 63% ± 3.15% of CRD-activated neurons in LI projecting to the PbN. On the other hand, at the LS spinal level, only 18% ± 0.6% of CRD-activated neurons in LI projected to the PbN. The collective data identify differences in the central neuroanatomy that support the disparate roles of vagal and spinal afferent signaling in the facilitation and modulation of colorectal nociceptive responses.
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Affiliation(s)
- QingQing Wang
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
- Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Sonia Garcia Caraballo
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
- Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Grigori Rychkov
- Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
- School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Alice E McGovern
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Stuart B Mazzone
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Stuart M Brierley
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
- Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
- School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Andrea M Harrington
- Visceral Pain Research Group, College of Medicine and Public Health, Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
- Hopwood Centre for Neurobiology, Lifelong Health, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
- School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
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Ringuet MT, Koo A, Furness SGB, McDougall SJ, Furness JB. Sites and mechanisms of action of colokinetics at dopamine, ghrelin and serotonin receptors in the rodent lumbosacral defecation centre. J Physiol 2023; 601:5195-5211. [PMID: 37772438 PMCID: PMC10952827 DOI: 10.1113/jp285217] [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: 07/04/2023] [Accepted: 09/13/2023] [Indexed: 09/30/2023] Open
Abstract
Agonists of dopamine D2 receptors (D2R), 5-hydroxytryptamine (5-HT, serotonin) receptors (5-HTR) and ghrelin receptors (GHSR) activate neurons in the lumbosacral defecation centre, and act as 'colokinetics', leading to increased propulsive colonic motility, in vivo. In the present study, we investigated which neurons in the lumbosacral defecation centre express the receptors and whether dopamine, serotonin and ghrelin receptor agonists act on the same lumbosacral preganglionic neurons (PGNs). We used whole cell electrophysiology to record responses from neurons in the lumbosacral defecation centre, following colokinetic application, and investigated their expression profiles and the chemistries of their neural inputs. Fluorescence in situ hybridisation revealed Drd2, Ghsr and Htr2C transcripts were colocalised in lumbosacral PGNs of mice, and immunohistochemistry showed that these neurons have closely associated tyrosine hydroxylase and 5-HT boutons. Previous studies showed that they do not receive ghrelin inputs. Whole cell electrophysiology in adult mice spinal cord revealed that dopamine, serotonin, α-methylserotonin and capromorelin each caused inward, excitatory currents in overlapping populations of lumbosacral PGNs. Furthermore, dopamine caused increased frequency of both IPSCs and EPSCs in a cohort of D2R neurons. Tetrodotoxin blocked the IPSCs and EPSCs, revealing a post-synaptic excitatory action of dopamine. In lumbosacral PGNs of postnatal day 7-14 rats, only dopamine's postsynaptic effects were observed. Furthermore, inward, excitatory currents evoked by dopamine were reduced by the GHSR antagonist, YIL781. We conclude that lumbosacral PGNs are the site where the action of endogenous ligands of D2R and 5-HT2R converge, and that GHSR act as a cis-modulator of D2R expressed by the same neurons. KEY POINTS: Dopamine, 5-hydroxytryptamine (5-HT, serotonin) and ghrelin (GHSR) receptor agonists increase colorectal motility and have been postulated to act at receptors on parasympathetic preganglionic neurons (PGNs) in the lumbosacral spinal cord. We aimed to determine which neurons in the lumbosacral spinal cord express dopamine, serotonin and GHSR receptors, their neural inputs, and whether agonists at these receptors excite them. We show that dopamine, serotonin and ghrelin receptor transcripts are contained in the same PGNs and that these neurons have closely associated tyrosine hydroxylase and serotonin boutons. Whole cell electrophysiology revealed that dopamine, serotonin and GHSR receptor agonists induce an inward excitatory current in overlapping populations of lumbosacral PGNs. Dopamine-induced excitation was reversed by GHSR antagonism. The present study demonstrates that lumbosacral PGNs are the site at which actions of endogenous ligands of dopamine D2 receptors and 5-HT type 2 receptors converge. Ghrelin receptors are functional, but their role appears to be as modulators of dopamine effects at D2 receptors.
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Affiliation(s)
- Mitchell T. Ringuet
- Department of Anatomy & PhysiologyUniversity of MelbourneMelbourneVICAustralia
| | - Ada Koo
- Department of Anatomy & PhysiologyUniversity of MelbourneMelbourneVICAustralia
| | - Sebastian G. B. Furness
- School of Biomedical SciencesUniversity of QueenslandBrisbaneQLDAustralia
- Monash Institute of Pharmaceutical SciencesMelbourneVICAustralia
| | - Stuart J. McDougall
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneMelbourneVICAustralia
| | - John B. Furness
- Department of Anatomy & PhysiologyUniversity of MelbourneMelbourneVICAustralia
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneMelbourneVICAustralia
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Naitou K, Iwashita H, Ueda HH, Shiraishi M, Fujimoto Y, Horii K, Sawamura T, Shiina T, Shimizu Y. Intrathecally administered substance P activated the spinal defecation center and enhanced colorectal motility in anesthetized rats. Am J Physiol Gastrointest Liver Physiol 2022; 323:G21-G30. [PMID: 35470689 DOI: 10.1152/ajpgi.00342.2021] [Citation(s) in RCA: 1] [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
Noxious stimuli on the colorectum cause colorectal contractions through activation of descending monoaminergic pathways projecting from the supraspinal defecation center to the spinal defecation center. Since it is known that substance P is involved in the response to peripheral noxious stimuli in the spinal cord, we investigated the effects of intrathecally administered substance P at L6-S1 levels on colorectal motility in rats that were anesthetized with α-chloralose and ketamine. Intrathecally administered substance P enhanced colorectal motility, even after transection of the thoracic spinal cord at the T4 level. Severing the pelvic nerves, but not the colonic nerves, abolished substance P enhanced colorectal motility. In the spinal cord at L6-S1 levels, expression of mRNA coding neurokinin (NK) 1-3 receptors was detected by RT-PCR. Immunohistological experiments revealed that preganglionic neurons of the pelvic nerves express NK1 receptors, whereas expression of NK2 receptors was not found. In addition, substance P-containing fibers densely innervated around the preganglionic neurons expressing NK1 receptors. An intrathecally administered NK1 receptor antagonist (spantide) attenuated capsaicin-induced colorectal contractions. These results suggest that the colokinetic action of substance P is mediated by the NK1 receptor in the spinal defecation center. Our findings indicate that substance P may function as a neurotransmitter in the spinal defecation center.NEW & NOTEWORTHY We found that intrathecally administered substance P enhanced colorectal motility in anesthetized rats. Neurokinin (NK) 1 receptors, but not NK2 receptors, were detected in preganglionic neurons of the pelvic nerves. Blockade of NK1 receptors in the spinal cord attenuated the enhanced colorectal motility in response to intracolonic noxious stimuli. The findings indicate that substance P may function as a neurotransmitter in the spinal reflex pathway controlling defecation.
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Affiliation(s)
- Kiyotada Naitou
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Honoka Iwashita
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Hiromi H Ueda
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Mitsuya Shiraishi
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Yoshikazu Fujimoto
- Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Kazuhiro Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Tomoya Sawamura
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
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Horii K, Sawamura T, Onishi A, Yuki N, Naitou K, Shiina T, Shimizu Y. Contribution of sex hormones to the sexually dimorphic response of colorectal motility to noxious stimuli in rats. Am J Physiol Gastrointest Liver Physiol 2022; 323:G1-G8. [PMID: 35438007 DOI: 10.1152/ajpgi.00033.2022] [Citation(s) in RCA: 1] [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
Our recent studies have shown that noxious stimuli in the colorectum enhance colorectal motility via the brain and spinal defecation centers in male rats. In female rats, however, noxious stimuli have no effect on colorectal motility. The purpose of this study was to determine whether sex hormones are major contributing factors for sex-dependent differences in neural components of the spinal defecation center. Colorectal motility was measured using an in vivo method under ketamine and α-chloralose anesthesia in rats. Capsaicin was administered into the colorectal lumen as noxious stimuli. Orchiectomy in male rats had no effect on the capsaicin-induced response of colorectal motility. However, in ovariectomized female rats, capsaicin administration enhanced colorectal motility, though intact female animals did not show enhanced motility. When estradiol was administered by using a sustained-release preparation in ovariectomized female rats, capsaicin administration did not enhance colorectal motility unless a GABAA receptor antagonist was intrathecally administered to the lumbosacral spinal cord. These findings suggest that estradiol allowed the GABAergic neurons to operate in response to intracolonic administration of capsaicin. The operation of GABAergic inhibition by the action of estradiol could be manifested in male rats only when the effects of male sex hormones were removed by orchiectomy. Taken together, our results indicate that sex hormones contribute to the sexually dimorphic response in colorectal motility enhancement in response to noxious stimuli through modulating GABAergic pathways.NEW & NOTEWORTHY This study demonstrated that estradiol permits inhibitory regulation in the spinal defecation center not only in female rats but also in orchiectomized male rats. GABAergic pathways are likely involved in the effect of estradiol. This is the first report showing that sex hormones affect colorectal motility through the alteration of neural components of the regulatory pathways. Our findings provide a novel insight into pathophysiological mechanisms of defecation disorders related to changes in sex hormones.
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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, Gifu, Japan
| | - Tomoya Sawamura
- Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Ayaka Onishi
- Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Natsufu Yuki
- Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Kiyotada Naitou
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan
| | - Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.,Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.,Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
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Galligan JJ. Colonic 5-HT 4 receptors are targets for novel prokinetic drugs. Neurogastroenterol Motil 2021; 33:e14125. [PMID: 33749067 DOI: 10.1111/nmo.14125] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 02/22/2021] [Indexed: 12/17/2022]
Abstract
5-HT4 receptors are G protein-coupled receptors that link to the stimulatory protein Gs which activates adenylate cyclase to increase intracellular cyclic AMP which then activates protein kinase A (PKA). 5-HT4 receptors are expressed by neurons in the central and peripheral nervous systems especially the enteric nervous system (ENS). In general, 5-HT4 receptors are stimulatory and their activation in the ENS enhances neurotransmitter release and propulsive motility patterns. 5-HT4 receptors are expressed by enterochromaffin (EC) cells, Goblet cells, and most enteric neurons. The study by Konen and colleagues in this issue of Neurogastroenterology and Motility features two novel 5-HT4 receptor agonists (5-HT4 -LA1 and 5-HT4 -LA-2) that are not absorbed from the gastrointestinal tract of mice and act locally in the colonic mucosa to stimulate propulsive motility. The authors show that 5-HT4 -LA1 and 5-HT4 -LA2 were not absorbed from the colon and that both drugs stimulated colonic transit when administered by gavage. Both agonists stimulated colonic glass bead expulsion, and 5-HT4 LA1 activation stimulated fecal output and increased fecal water content. These effects were detected in young and aged mice. 5-HT4 receptors were also localized to the epithelium of the human duodenum, ileum, and colon. These studies highlight novel 5-HT4 receptor agonists that have prokinetic actions on the GI tract. These drugs are not absorbed and act locally in the gut mucosa to stimulate propulsive motility while minimizing access to systemic 5-HT4 receptors and avoiding potential unwanted side effects.
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Affiliation(s)
- James J Galligan
- Department of Pharmacology & Toxicology and the Neuroscience Program, Michigan State University, East Lansing, MI, USA
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Ueda HH, Naitou K, Nakamori H, Horii K, Shiina T, Masatani T, Shiraishi M, Shimizu Y. α-MSH-induced activation of spinal MC1R but not MC4R enhances colorectal motility in anaesthetised rats. Sci Rep 2021; 11:487. [PMID: 33436759 PMCID: PMC7803980 DOI: 10.1038/s41598-020-80020-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 12/11/2020] [Indexed: 12/15/2022] Open
Abstract
The central nervous system is involved in regulation of defaecation. It is generally considered that supraspinal regions control the spinal defaecation centre. However, signal transmission from supraspinal regions to the spinal defaecation centre is still unclear. In this study, we investigated the regulatory role of an anorexigenic neuropeptide, α-MSH, in the spinal defaecation centre in rats. Intrathecal administration of α-MSH to the L6-S1 spinal cord enhanced colorectal motility. The prokinetic effect of α-MSH was abolished by severing the pelvic nerves. In contrast, severing the colonic nerves or thoracic cord transection at the T4 level had no impact on the effect of α-MSH. RT-PCR analysis revealed MC1R mRNA and MC4R mRNA expression in the L6-S1 spinal cord. Intrathecally administered MC1R agonists, BMS470539 and SHU9119, mimicked the α-MSH effect, but a MC4R agonist, THIQ, had no effect. These results demonstrate that α-MSH binds to MC1R in the spinal defaecation centre and activates pelvic nerves, leading to enhancement of colorectal motility. This is, to our knowledge, the first report showing the functional role of α-MSH in the spinal cord. In conclusion, our findings suggest that α-MSH is a candidate for a neurotransmitter from supraspinal regions to the spinal defaecation centre.
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Affiliation(s)
- Hiromi H Ueda
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan
| | - Kiyotada Naitou
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan
| | - Hiroyuki Nakamori
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan
| | - Kazuhiro Horii
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Takahiko Shiina
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Tatsunori Masatani
- Transboundary Animal Diseases Research Center, Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, 890-0065, Japan
| | - Mitsuya Shiraishi
- Department of Basic Veterinary Science, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan
| | - Yasutake Shimizu
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan. .,Center for Highly Advanced Integration of Nano and Life Sciences, Gifu University (G-CHAIN), Gifu, Japan.
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Horii K, Ehara Y, Shiina T, Naitou K, Nakamori H, Horii Y, Shimaoka H, Saito S, Shimizu Y. Sexually dimorphic response of colorectal motility to noxious stimuli in the colorectum in rats. J Physiol 2020; 599:1421-1437. [PMID: 33347601 DOI: 10.1113/jp279942] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 12/02/2020] [Indexed: 12/17/2022] Open
Abstract
KEY POINTS This study showed a remarkable sex difference in responses of colorectal motility to noxious stimuli in the colorectum in rats: colorectal motility was enhanced in response to intracolonic administration of a noxious stimulant, capsaicin, in male rats but not in female rats. The difference in descending neurons from the brain to spinal cord operating after noxious stimulation could be responsible for the sex difference. In male rats, serotoninergic and dopaminergic neurons are dominantly activated, both of which activate the spinal defaecation centre. In female rats, GABAergic neurons in addition to serotoninergic neurons are activated. GABA may compete for facilitative action of 5-HT in the spinal defaecation centre, and thereby colorectal motility is not enhanced in response to intracolonic administration of capsaicin. The findings provide a novel insight into pathophysiological mechanisms of sex differences in functional defaecation disorders such as irritable bowel syndrome. ABSTRACT We previously demonstrated that noxious stimuli in the colorectum enhance colorectal motility through activation of descending pain inhibitory pathways in male rats. It can be expected that the regulatory mechanisms of colorectal motility differ in males and females owing to remarkable sex differences in descending pain inhibitory pathways. Thus, we aimed to clarify sex differences in responses of colorectal motility to noxious stimuli in rats. Colorectal motility was measured in vivo in anaesthetized rats. Administration of a noxious stimulant, capsaicin, into the colorectal lumen enhanced colorectal motility in male rats but not in female rats. Quantitative PCR and immunohistochemistry showed that TRPV1 expression levels in the dorsal root ganglia and in the colorectal mucosa were comparable in male and female rats. When a GABAA receptor inhibitor was intrathecally administered to the L6-S1 level of the spinal cord, colorectal motility was facilitated in response to intracolonic capsaicin even in female rats. The capsaicin-induced response in the presence of the GABA blocker in female rats was inhibited by intrathecal administration of 5-HT2 and -3 receptor antagonists but not by a D2-like dopamine receptor antagonist. Our findings demonstrate that intracolonic noxious stimulation activates GABAergic and serotoninergic descending neurons in female rats, whereas serotoninergic and dopaminergic neurons are dominantly activated in male rats. Thus, the difference in the descending neurons operating after noxious stimulation would be responsible for the sexually dimorphic responses of colorectal motility. Our findings provide a novel insight into pathophysiological mechanisms of sex differences in functional defaecation disorders such as irritable bowel syndrome.
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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, Gifu, Japan
| | - Yuka Ehara
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Kiyotada Naitou
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Hiroyuki Nakamori
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Yuuki Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Hiroki Shimaoka
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Shouichiro Saito
- Department of Basic Veterinary Science, Laboratory of Anatomy, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, 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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10
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5-HT6 receptor antagonism reduces defecation in rat: A potential treatment strategy for irritable bowel syndrome with diarrhea. Eur J Pharmacol 2019; 864:172718. [DOI: 10.1016/j.ejphar.2019.172718] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/01/2019] [Accepted: 10/02/2019] [Indexed: 12/14/2022]
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11
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Nakamori H, Naitou K, Horii Y, Shimaoka H, Horii K, Sakai H, Yamada A, Furue H, Shiina T, Shimizu Y. Roles of the noradrenergic nucleus locus coeruleus and dopaminergic nucleus A11 region as supraspinal defecation centers in rats. Am J Physiol Gastrointest Liver Physiol 2019; 317:G545-G555. [PMID: 31460791 DOI: 10.1152/ajpgi.00062.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We previously demonstrated that administration of norepinephrine, dopamine, and serotonin into the lumbosacral defecation center caused propulsive contractions of the colorectum. It is known that the monoamines in the spinal cord are released mainly from descending neurons in the brainstem. In fact, stimulation of the medullary raphe nuclei, the origin of descending serotonergic neurons, enhances colorectal motility via the lumbosacral defecation center. Therefore, the purpose of this study was to examine the roles of the noradrenergic nucleus locus coeruleus (LC) and dopaminergic nucleus A11 region in the defecation reflex. Colorectal motility was measured with a balloon in anesthetized rats. Electrical stimulation of the LC and A11 region increased colorectal pressure only when a GABAA receptor antagonist was injected into the lumbosacral spinal cord. The effects of the LC stimulation and A11 region stimulation on colorectal motility were inhibited by antagonists of α1-adrenoceptors and D2-like dopamine receptors injected into the lumbosacral spinal cord, respectively. Spinal injection of a norepinephrine-dopamine reuptake inhibitor augmented the colokinetic effect of LC stimulation. The effect of stimulation of each nucleus was abolished by surgical severing of the parasympathetic pelvic nerves. Our findings demonstrate that activation of descending noradrenergic neurons from the LC and descending dopaminergic neurons from the A11 region causes enhancement of colorectal motility via the lumbosacral defecation center. The present study provides a novel concept that the brainstem monoaminergic nuclei play a role as supraspinal defecation centers.NEW & NOTEWORTHY The present study demonstrates that electrical and chemical stimulations of the locus coeruleus or A11 region augment contractions of the colorectum. The effects of locus coeruleus and A11 stimulations on colorectal motility are due to activation of α1-adrenoceptors and D2-like dopamine receptors in the lumbosacral defecation center, respectively. The present study provides a novel concept that the brainstem monoaminergic nuclei play a role as supraspinal defecation centers.
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Affiliation(s)
- Hiroyuki Nakamori
- Department of Basic Veterinary Science, Laboratory of Physiology, United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Kiyotada Naitou
- Department of Basic Veterinary Science, Laboratory of Physiology, United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Yuuki Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Hiroki Shimaoka
- Department of Basic Veterinary Science, Laboratory of Physiology, United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Kazuhiro Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Hiroki Sakai
- Department of Pathogenetic Veterinary Science, Laboratory of Pathology, 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
| | - Akihiro Yamada
- Department of Neurophysiology, Hyogo College of Medicine, Nishinomiya, Japan
| | - Hidemasa Furue
- Department of Neurophysiology, Hyogo College of Medicine, Nishinomiya, Japan
| | - Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, 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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12
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Steuer I, Guertin PA. Central pattern generators in the brainstem and spinal cord: an overview of basic principles, similarities and differences. Rev Neurosci 2019; 30:107-164. [PMID: 30543520 DOI: 10.1515/revneuro-2017-0102] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/30/2018] [Indexed: 12/11/2022]
Abstract
Central pattern generators (CPGs) are generally defined as networks of neurons capable of enabling the production of central commands, specifically controlling stereotyped, rhythmic motor behaviors. Several CPGs localized in brainstem and spinal cord areas have been shown to underlie the expression of complex behaviors such as deglutition, mastication, respiration, defecation, micturition, ejaculation, and locomotion. Their pivotal roles have clearly been demonstrated although their organization and cellular properties remain incompletely characterized. In recent years, insightful findings about CPGs have been made mainly because (1) several complementary animal models were developed; (2) these models enabled a wide variety of techniques to be used and, hence, a plethora of characteristics to be discovered; and (3) organizations, functions, and cell properties across all models and species studied thus far were generally found to be well-preserved phylogenetically. This article aims at providing an overview for non-experts of the most important findings made on CPGs in in vivo animal models, in vitro preparations from invertebrate and vertebrate species as well as in primates. Data about CPG functions, adaptation, organization, and cellular properties will be summarized with a special attention paid to the network for locomotion given its advanced level of characterization compared with some of the other CPGs. Similarities and differences between these networks will also be highlighted.
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Affiliation(s)
- Inge Steuer
- Neuroscience Unit, Laval University Medical Center (CHUL - CHU de Québec), 2705 Laurier Blvd, Quebec City, Quebec G1V 4G2, Canada
| | - Pierre A Guertin
- Neuroscience Unit, Laval University Medical Center (CHUL - CHU de Québec), 2705 Laurier Blvd, Quebec City, Quebec G1V 4G2, Canada
- Faculty of Medicine, Department of Psychiatry and Neurosciences, Laval University, Quebec City, Quebec G1V 0A6, Canada
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13
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Naitou K, Nakamori H, Horii K, Kato K, Horii Y, Shimaoka H, Shiina T, Shimizu Y. Descending monoaminergic pathways projecting to the spinal defecation center enhance colorectal motility in rats. Am J Physiol Gastrointest Liver Physiol 2018; 315:G631-G637. [PMID: 30070581 DOI: 10.1152/ajpgi.00178.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The central regulating mechanisms of defecation, especially roles of the spinal defecation center, are still unclear. We have shown that monoamines including norepinephrine, dopamine, and serotonin injected into the spinal defecation center cause propulsive contractions of the colorectum. These monoamines are the main neurotransmitters of descending pain inhibitory pathways. Therefore, we hypothesized that noxious stimuli in the colorectum would activate the descending monoaminergic pathways projecting to the spinal defecation center and that subsequently released endogenous monoamine neurotransmitters would enhance colorectal motility. Colorectal motility was measured in rats anesthetized with α-chloralose and ketamine. As a noxious stimulus, capsaicin was administered into the colorectal lumen. To interrupt neuronal transmission in the spinal defecation center, antagonists of norepinephrine, dopamine, and/or serotonin receptors were injected intrathecally at the L6-S1 spinal level, where the spinal defecation center is located. Intraluminal administration of capsaicin, acting on the transient receptor potential vanilloid 1 channel, caused transient propulsive contractions. The effect of capsaicin was abolished by surgical severing of the pelvic nerves or thoracic spinal transection at the T4 level. Capsaicin-induced contractions were blocked by preinjection of D2-like dopamine receptor and 5-hydroxytryptamine subtype 2 and 3 receptor antagonists into the spinal defecation center. We demonstrated that intraluminally administered capsaicin causes propulsive colorectal motility through reflex pathways involving the spinal and supraspinal defecation centers. Our results provide evidence that descending monoaminergic neurons are activated by noxious stimulation to the colorectum, leading to facilitation of colorectal motility. NEW & NOTEWORTHY The present study demonstrates that noxious stimuli in the colorectum activates the descending monoaminergic pathways projecting to the spinal defecation center and that subsequently released endogenous monoamine neurotransmitters, serotonin and dopamine, enhance colorectal motility. Our findings provide a possible explanation of the concurrent appearance of abdominal pain and bowel disorder in irritable bowel syndrome patients. Thus the present study may provide new insights into understanding of mechanisms of colorectal dysfunction involving the central nervous system.
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Affiliation(s)
- 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
| | - Kazuhiro Horii
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University , Gifu , Japan
| | - Kurumi Kato
- 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
| | - Takahiko Shiina
- 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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