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Lowenstein ED, Ruffault PL, Misios A, Osman KL, Li H, Greenberg RS, Thompson R, Song K, Dietrich S, Li X, Vladimirov N, Woehler A, Brunet JF, Zampieri N, Kühn R, Liberles SD, Jia S, Lewin GR, Rajewsky N, Lever TE, Birchmeier C. Prox2 and Runx3 vagal sensory neurons regulate esophageal motility. Neuron 2023; 111:2184-2200.e7. [PMID: 37192624 DOI: 10.1016/j.neuron.2023.04.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 10/31/2022] [Accepted: 04/24/2023] [Indexed: 05/18/2023]
Abstract
Vagal sensory neurons monitor mechanical and chemical stimuli in the gastrointestinal tract. Major efforts are underway to assign physiological functions to the many distinct subtypes of vagal sensory neurons. Here, we use genetically guided anatomical tracing, optogenetics, and electrophysiology to identify and characterize vagal sensory neuron subtypes expressing Prox2 and Runx3 in mice. We show that three of these neuronal subtypes innervate the esophagus and stomach in regionalized patterns, where they form intraganglionic laminar endings. Electrophysiological analysis revealed that they are low-threshold mechanoreceptors but possess different adaptation properties. Lastly, genetic ablation of Prox2 and Runx3 neurons demonstrated their essential roles for esophageal peristalsis in freely behaving mice. Our work defines the identity and function of the vagal neurons that provide mechanosensory feedback from the esophagus to the brain and could lead to better understanding and treatment of esophageal motility disorders.
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Affiliation(s)
- Elijah D Lowenstein
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, Berlin, Germany; NeuroCure Cluster of Excellence, CharitéUniversitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Pierre-Louis Ruffault
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Aristotelis Misios
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, Berlin, Germany; NeuroCure Cluster of Excellence, CharitéUniversitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany; Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Kate L Osman
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Huimin Li
- The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Rachel S Greenberg
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Rebecca Thompson
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Kun Song
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Stephan Dietrich
- Development and Function of Neural Circuits, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Xun Li
- Immune Regulation and Cancer, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Nikita Vladimirov
- Systems Biology Imaging, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Andrew Woehler
- Systems Biology Imaging, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Jean-François Brunet
- Institut de Biologie de l'ENS (IBENS), Inserm, CNRS, École normale supérieure, PSL Research University, Paris, France
| | - Niccolò Zampieri
- Development and Function of Neural Circuits, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Ralf Kühn
- Genome Engineering & Disease Models, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Stephen D Liberles
- Howard Hughes Medical Institute, Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Shiqi Jia
- The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Gary R Lewin
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Nikolaus Rajewsky
- Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Teresa E Lever
- Department of Otolaryngology - Head & Neck Surgery, University of Missouri School of Medicine, Columbia, MO, USA
| | - Carmen Birchmeier
- Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, Berlin, Germany; NeuroCure Cluster of Excellence, CharitéUniversitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
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2
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Yu J. Multiple sensor theory in airway mechanosensory units. Respir Physiol Neurobiol 2023; 313:104071. [PMID: 37149207 DOI: 10.1016/j.resp.2023.104071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/12/2023] [Accepted: 05/02/2023] [Indexed: 05/08/2023]
Abstract
Two conventional doctrines govern airway mechanosensory interpretation: One-Sensor Theory (OST) and Line-Labeled Theory (LLT). In OST, one afferent fiber connects to a single sensor. In LLT, a different type of sensor sends signals via its specific line to a particular brain region to evoke its reflex. Thus, airway slowly adapting receptors (SARs) inhibit breathing and rapidly adapting receptors (RARs) stimulate breathing. However, recent studies show many different mechanosensors connect to a single afferent fiber (Multiple-Sensor Theory, MST). That is, SARs and RARs may send different types of information through the same afferent pathway, indicating different information has been integrated at the sensory unit level. Thus, a sensory unit is not merely a transducer (textbook concept), but also a processor. MST is a conceptual shift. Data generated over last eight decades under OST require re-interpretation.
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Affiliation(s)
- Jerry Yu
- Department of Pulmonary Medicine, University of Louisville, Louisville, KY 40292, Robley Rex VA Medical Center, Louisville, KY 40206, USA.
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da Silva‐Alves KS, Ferreira‐da‐Silva FW, Coelho‐de‐Souza AN, Weinreich D, Leal‐Cardoso JH. Diabetes mellitus differently affects electrical membrane properties of vagal afferent neurons of rats. Physiol Rep 2023; 11:e15605. [PMID: 36807809 PMCID: PMC9938008 DOI: 10.14814/phy2.15605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 01/24/2023] [Accepted: 01/26/2023] [Indexed: 02/20/2023] Open
Abstract
To study whether diabetes mellitus (DM) would cause electrophysiological alterations in nodose ganglion (NG) neurons, we used patch clamp and intracellular recording for voltage and current clamp configuration, respectively, on cell bodies of NG from rats with DM. Intracellular microelectrodes recording, according to the waveform of the first derivative of the action potential, revealed three neuronal groups (A0 , Ainf , and Cinf ), which were differently affected. Diabetes only depolarized the resting potential of A0 (from -55 to -44 mV) and Cinf (from -49 to -45 mV) somas. In Ainf neurons, diabetes increased action potential and the after-hyperpolarization durations (from 1.9 and 18 to 2.3 and 32 ms, respectively) and reduced dV/dtdesc (from -63 to -52 V s-1 ). Diabetes reduced the action potential amplitude while increasing the after-hyperpolarization amplitude of Cinf neurons (from 83 and -14 mV to 75 and -16 mV, respectively). Using whole cell patch clamp recording, we observed that diabetes produced an increase in peak amplitude of sodium current density (from -68 to -176 pA pF-1 ) and displacement of steady-state inactivation to more negative values of transmembrane potential only in a group of neurons from diabetic animals (DB2). In the other group (DB1), diabetes did not change this parameter (-58 pA pF-1 ). This change in sodium current did not cause an increase in membrane excitability, probably explainable by the alterations in sodium current kinetics, which are also induced by diabetes. Our data demonstrate that diabetes differently affects membrane properties of different nodose neuron subpopulations, which likely have pathophysiological implications for diabetes mellitus.
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Affiliation(s)
- Kerly Shamyra da Silva‐Alves
- Laboratory of Electrophysiology, Superior Institute of Biomedical SciencesState University of CearáFortalezaBrazil
| | - Francisco Walber Ferreira‐da‐Silva
- Laboratory of Electrophysiology, Superior Institute of Biomedical SciencesState University of CearáFortalezaBrazil,Technological and Exact Science CenterState University Vale do AcaraúSobralBrazil
| | - Andrelina Noronha Coelho‐de‐Souza
- Laboratory of Electrophysiology, Superior Institute of Biomedical SciencesState University of CearáFortalezaBrazil,Laboratory of Experimental Physiology, Superior Institute of Biomedical SciencesState University of CearáFortalezaBrazil
| | - Daniel Weinreich
- Department of PharmacologyUniversity of Maryland, School of MedicineBaltimoreMarylandUSA
| | - José Henrique Leal‐Cardoso
- Laboratory of Electrophysiology, Superior Institute of Biomedical SciencesState University of CearáFortalezaBrazil
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4
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Mota CMD. Autonomic nerves differentially control inflammation during endotoxaemia. J Physiol 2022; 600:5187-5188. [PMID: 36314444 DOI: 10.1113/jp283816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 10/27/2022] [Indexed: 11/06/2022] Open
Affiliation(s)
- Clarissa M D Mota
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, USA
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Ferstl M, Teckentrup V, Lin WM, Kräutlein F, Kühnel A, Klaus J, Walter M, Kroemer NB. Non-invasive vagus nerve stimulation boosts mood recovery after effort exertion. Psychol Med 2022; 52:3029-3039. [PMID: 33586647 PMCID: PMC9693679 DOI: 10.1017/s0033291720005073] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/30/2020] [Accepted: 12/03/2020] [Indexed: 01/05/2023]
Abstract
BACKGROUND Mood plays an important role in our life which is illustrated by the disruptive impact of aberrant mood states in depression. Although vagus nerve stimulation (VNS) has been shown to improve symptoms of depression, the exact mechanism is still elusive, and it is an open question whether non-invasive VNS could be used to swiftly and robustly improve mood. METHODS Here, we investigated the effect of left- and right-sided transcutaneous auricular VNS (taVNS) v. a sham control condition on mood after the exertion of physical and cognitive effort in 82 healthy participants (randomized cross-over design) using linear mixed-effects and hierarchical Bayesian analyses of mood ratings. RESULTS We found that 90 min of either left-sided or right-sided taVNS improved positive mood [b = 5.11, 95% credible interval, CI (1.39-9.01), 9.6% improvement relative to the mood intercept, BF10 = 7.69, pLME = 0.017], yet only during the post-stimulation phase. Moreover, lower baseline scores of positive mood were associated with greater taVNS-induced improvements in motivation [r = -0.42, 95% CI (-0.58 to -0.21), BF10 = 249]. CONCLUSIONS We conclude that taVNS boosts mood after a prolonged period of effort exertion with concurrent stimulation and that acute motivational effects of taVNS are partly dependent on initial mood states. Collectively, our results show that taVNS may help quickly improve affect after a mood challenge, potentially by modulating interoceptive signals contributing to the reappraisal of effortful behavior. This suggests that taVNS could be a useful add-on to current behavioral therapies.
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Affiliation(s)
- Magdalena Ferstl
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Vanessa Teckentrup
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Wy Ming Lin
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Franziska Kräutlein
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Anne Kühnel
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry and International Max Planck Research School for Translational Psychiatry (IMPRS-TP), Munich, Germany
| | - Johannes Klaus
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Martin Walter
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
- Department of Psychiatry and Psychotherapy, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
- Department of Psychiatry and Psychotherapy, University Hospital Jena, Jena, Germany
- Department of Behavioral Neurology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Nils B. Kroemer
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
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Nakamura U, Nohmi T, Sagane R, Hai J, Ohbayashi K, Miyazaki M, Yamatsu A, Kim M, Iwasaki Y. Dietary Gamma-Aminobutyric Acid (GABA) Induces Satiation by Enhancing the Postprandial Activation of Vagal Afferent Nerves. Nutrients 2022; 14:2492. [PMID: 35745222 DOI: 10.3390/nu14122492] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/06/2022] [Accepted: 06/13/2022] [Indexed: 12/07/2022] Open
Abstract
Gamma-aminobutyric acid (GABA) is present in the mammalian brain as the main inhibitory neurotransmitter and in foods. It is widely used as a supplement that regulates brain function through stress-reducing and sleep-enhancing effects. However, its underlying mechanisms remain poorly understood, as it is reportedly unable to cross the blood–brain barrier. Here, we explored whether a single peroral administration of GABA affects feeding behavior as an evaluation of brain function and the involvement of vagal afferent nerves. Peroral GABA at 20 and 200 mg/kg immediately before refeeding suppressed short-term food intake without aversive behaviors in mice. However, GABA administration 30 min before refeeding demonstrated no effects. A rise in circulating GABA concentrations by the peroral administration of 200 mg/kg GABA was similar to that by the intraperitoneal injection of 20 mg/kg GABA, which did not alter feeding. The feeding suppression by peroral GABA was blunted by the denervation of vagal afferents. Unexpectedly, peroral GABA alone did not alter vagal afferent activities histologically. The coadministration of a liquid diet and GABA potentiated the postprandial activation of vagal afferents, thereby enhancing postprandial satiation. In conclusion, dietary GABA activates vagal afferents in collaboration with meals or meal-evoked factors and regulates brain function including feeding behavior.
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7
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Liu P, Zelko IN, Yu J. A comparative study of bronchopulmonary slowly adapting receptors between rabbits and rats. Physiol Rep 2022; 10:e15069. [PMID: 35343655 PMCID: PMC8958495 DOI: 10.14814/phy2.15069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/08/2021] [Accepted: 09/12/2021] [Indexed: 11/24/2022] Open
Abstract
Pulmonary mechanosensory receptors provide important inputs to the respiratory center for control of breathing. However, what is known about their structure-function relationship is still limited. In these studies, we explored this relationship comparing bronchopulmonary slowly adapting receptor (SAR) units in rabbits and rats. In morphological studies, sensory units in tracheobronchial smooth muscle labeled with anti-Na+ /K+ -ATPase (α3 subunit) were found to be larger in the rabbit. Since larger structures may result from increased receptor size or more numerous receptors, further examination showed receptor size was the same in both species, but more receptors in a structure in rabbits than rats, accounting for their larger structure. In functional studies, SAR units were recorded electrically in anesthetized, open-chest, and artificially ventilated animals and responses to lung inflation were compared at three different constant airway pressures (10, 20, and 30 cmH2 O). At each level of the inflation, SAR discharge frequencies were found to be higher in rabbits than rats. We conclude that a relatively larger number of receptors in a sensory unit may be responsible for higher SAR activities in rabbit SAR units.
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Affiliation(s)
- Ping Liu
- Department of MedicineUniversity of LouisvilleLouisvilleKentucky40292USA
| | - Igor N. Zelko
- Department of MedicineUniversity of LouisvilleLouisvilleKentucky40292USA
| | - Jerry Yu
- Department of MedicineUniversity of LouisvilleLouisvilleKentucky40292USA
- Robley Rex VA Medical CenterLouisvilleKentucky40206USA
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8
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Abstract
Typically, unit discharge of slowly adapting receptors (SARs) declines slowly when lung inflation pressure is constant, although in some units it increases instead-a phenomenon hereinafter referred to as creeping. These studies characterize creeping behavior observed in 62 of 137 SAR units examined in anesthetized, open-chest, and mechanically ventilated rabbits. SAR units recorded from the cervical vagus nerve were studied during 4 s of constant lung inflation at 10, 20, and 30 cmH2O. Affected SAR units creep more quickly as inflation pressure increases. SAR units also often deactivate after creeping, i.e., their activity decreases or stops completely. Creeping likely results from encoder switching from a low discharge to a high discharge SAR, because it disappears in SAR units with multiple receptive fields after blocking a high discharge encoder in one field leaves low discharge encoders intact. The results support that encoder switching is a common mechanism operating in lung mechanosensory units.
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Affiliation(s)
- Jerry Yu
- Department of Medicine, University of Louisville, Louisville, Kentucky and Robley Rex VA Medical Center, Louisville, Kentucky
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9
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Page AJ. Gastrointestinal Vagal Afferents and Food Intake: Relevance of Circadian Rhythms. Nutrients 2021; 13:nu13030844. [PMID: 33807524 PMCID: PMC7998414 DOI: 10.3390/nu13030844] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/25/2021] [Accepted: 03/03/2021] [Indexed: 01/20/2023] Open
Abstract
Gastrointestinal vagal afferents (VAs) play an important role in food intake regulation, providing the brain with information on the amount and nutrient composition of a meal. This is processed, eventually leading to meal termination. The response of gastric VAs, to food-related stimuli, is under circadian control and fluctuates depending on the time of day. These rhythms are highly correlated with meal size, with a nadir in VA sensitivity and increase in meal size during the dark phase and a peak in sensitivity and decrease in meal size during the light phase in mice. These rhythms are disrupted in diet-induced obesity and simulated shift work conditions and associated with disrupted food intake patterns. In diet-induced obesity the dampened responses during the light phase are not simply reversed by reverting back to a normal diet. However, time restricted feeding prevents loss of diurnal rhythms in VA signalling in high fat diet-fed mice and, therefore, provides a potential strategy to reset diurnal rhythms in VA signalling to a pre-obese phenotype. This review discusses the role of the circadian system in the regulation of gastrointestinal VA signals and the impact of factors, such as diet-induced obesity and shift work, on these rhythms.
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Affiliation(s)
- Amanda J. Page
- Adelaide Medical School, University of Adelaide, Adelaide, SA 5000, Australia; ; Tel.: +61-8-8128-4840
- Nutrition, Diabetes and Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institution (SAHMRI), Adelaide, SA 5000, Australia
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10
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Malbert CH. Vagally Mediated Gut-Brain Relationships in Appetite Control-Insights from Porcine Studies. Nutrients 2021; 13:nu13020467. [PMID: 33573329 PMCID: PMC7911705 DOI: 10.3390/nu13020467] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 01/07/2023] Open
Abstract
Signals arising from the upper part of the gut are essential for the regulation of food intake, particularly satiation. This information is supplied to the brain partly by vagal nervous afferents. The porcine model, because of its sizeable gyrencephalic brain, omnivorous regimen, and comparative anatomy of the proximal part of the gut to that of humans, has provided several important insights relating to the relevance of vagally mediated gut-brain relationships to the regulation of food intake. Furthermore, its large size combined with the capacity to become obese while overeating a western diet makes it a pivotal addition to existing murine models, especially for translational studies relating to obesity. How gastric, proximal intestinal, and portal information relating to meal arrival and transit are encoded by vagal afferents and their further processing by primary and secondary brain projections are reviewed. Their peripheral and central plasticities in the context of obesity are emphasized. We also present recent insights derived from chronic stimulation of the abdominal vagi with specific reference to the modulation of mesolimbic structures and their role in the restoration of insulin sensitivity in the obese miniature pig model.
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Affiliation(s)
- Charles-Henri Malbert
- Aniscan Unit, INRAE, Saint-Gilles, 35590 Paris, France;
- National Academy of Medicine, 75000 Paris, France
- Adelaide Medical School, University of Adelaide, Adelaide, SA 5000, Australia
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Abstract
The adaptability of the central nervous system has been revealed in several model systems. Of particular interest to central nervous system-injured individuals is the ability for neural components to be modified for regain of function. In both types of neurotrauma, traumatic brain injury and spinal cord injury, the primary parasympathetic control to the gastrointestinal tract, the vagus nerve, remains anatomically intact. However, individuals with traumatic brain injury or spinal cord injury are highly susceptible to gastrointestinal dysfunctions. Such gastrointestinal dysfunctions attribute to higher morbidity and mortality following traumatic brain injury and spinal cord injury. While the vagal efferent output remains capable of eliciting motor responses following injury, evidence suggests impairment of the vagal afferents. Since sensory input drives motor output, this review will discuss the normal and altered anatomy and physiology of the gastrointestinal vagal afferents to better understand the contributions of vagal afferent plasticity following neurotrauma.
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Affiliation(s)
- Emily N Blanke
- Department of Neural and Behavioral Sciences, Penn State University College of Medicine, Hershey, PA, USA
| | - Gregory M Holmes
- Department of Neural and Behavioral Sciences, Penn State University College of Medicine, Hershey, PA, USA
| | - Emily M Besecker
- Department of Health Sciences, Gettysburg College, Gettysburg, PA, USA
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12
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Ohbayashi K, Oyama Y, Yamaguchi C, Asano T, Yada T, Iwasaki Y. Gastrointestinal Distension by Pectin-Containing Carbonated Solution Suppresses Food Intake and Enhances Glucose Tolerance via GLP-1 Secretion and Vagal Afferent Activation. Front Endocrinol (Lausanne) 2021; 12:676869. [PMID: 34168616 PMCID: PMC8217665 DOI: 10.3389/fendo.2021.676869] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 05/10/2021] [Indexed: 12/13/2022] Open
Abstract
Diet-induced gastrointestinal distension is known to evoke satiation and suppress postprandial hyperglycemia; however, the underlying mechanisms remain poorly understood. This study explored how gastrointestinal distension regulates energy homeostasis by using inflating stomach formulation (ISF), the carbonated solution containing pectin that forms stable gel bubbles under acidic condition in the stomach. Here we show that, in mice, oral administration of ISF induced distension of stomach and proximal intestine temporarily, stimulated intestinal glucagon-like peptide-1 (GLP-1) secretion, and activated vagal afferents and brainstem. ISF suppressed food intake and improved glucose tolerance via enhancing insulin sensitivity. The anorexigenic effect was partially inhibited, and the beneficial glycemic effect was blunted by pharmacological GLP-1 receptor blockade and chemical denervation of capsaicin-sensitive sensory nerves. In HFD-fed obese mice showing arrhythmic feeding and obesity, subchronic ISF treatment at the light period (LP) onset for 10 days attenuated LP hyperphagia and visceral fat accumulation. These results demonstrate that gastrointestinal distension by ISF stimulates GLP-1 secretion and the vagal afferent signaling to the brain, thereby regulating feeding behavior and glucose tolerance. Furthermore, subchronic ISF treatment ameliorates HFD-induced visceral obesity. We propose the diet that induces gastrointestinal distension as a novel treatment of hyperphagic obesity and diabetes.
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Affiliation(s)
- Kento Ohbayashi
- Laboratory of Animal Science, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
| | - Yukiko Oyama
- Self-Medication R&D Laboratories, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
| | - Chiharu Yamaguchi
- Self-Medication R&D Laboratories, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
| | - Toshiki Asano
- Self-Medication R&D Laboratories, Taisho Pharmaceutical Co., Ltd., Saitama, Japan
| | - Toshihiko Yada
- Division of Integrative Physiology, Kansai Electric Power Medical Research Institute, Kobe, Japan
- Division of Diabetes and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yusaku Iwasaki
- Laboratory of Animal Science, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
- *Correspondence: Yusaku Iwasaki,
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13
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Patil MJ, Ru F, Sun H, Wang J, Kolbeck RR, Dong X, Kollarik M, Canning BJ, Undem BJ. Acute activation of bronchopulmonary vagal nociceptors by type I interferons. J Physiol 2020; 598:5541-5554. [PMID: 32924209 DOI: 10.1113/jp280276] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/17/2020] [Indexed: 12/14/2022] Open
Abstract
KEY POINTS Type I interferon receptors are expressed by the majority of vagal C-fibre neurons innervating the respiratory tract Interferon alpha and beta acutely and directly activate vagal C-fibers in the airways. The interferon-induced activation of C-fibers occurs secondary to stimulation of type 1 interferon receptors Type 1 interferons may contribute to the symptoms as well as the spread of respiratory viral infections by causing coughing and other defensive reflexes associated with vagal C-fibre activation ABSTRACT: We evaluated the ability of type I interferons to acutely activate airway vagal afferent nerve terminals in mouse lungs. Using single cell RT-PCR of lung-specific vagal neurons we found that IFNAR1 and IFNAR2 were expressed in 70% of the TRPV1-positive neurons (a marker for vagal C-fibre neurons) and 44% of TRPV1-negative neurons. We employed an ex vivo vagal innervated mouse trachea-lung preparation to evaluate the effect of interferons in directly activating airway nerves. Utilizing 2-photon microscopy of the nodose ganglion neurons from Pirt-Cre;R26-GCaMP6s mice we found that applying IFNα or IFNβ to the lungs acutely activated the majority of vagal afferent nerve terminals. When the type 1 interferon receptor, IFNAR1, was blocked with a blocking antibody the response to IFNβ was largely inhibited. The type 2 interferon, IFNγ, also activated airway nerves and this was not inhibited by the IFNAR1 blocking antibody. The Janus kinase inhibitor GLPG0634 (1 μm) virtually abolished the nerve activation caused by IFNβ. Consistent with the activation of vagal afferent C-fibers, infusing IFNβ into the mouse trachea led to defensive breathing reflexes including apneas and gasping. These reflexes were prevented by pretreatment with an IFN type-1 receptor blocking antibody. Finally, using whole cell patch-clamp electrophysiology of lung-specific neurons we found that IFNβ (1000 U ml-1 ) directly depolarized the membrane potential of isolated nodose neurons, in some cases beyond to action potential threshold. This acute non-genomic activation of vagal sensory nerve terminals by interferons may contribute to the incessant coughing that is a hallmark of respiratory viral infections.
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Affiliation(s)
- Mayur J Patil
- The Johns Hopkins School of Medicine Departments of Medicine, Baltimore, MD
| | - Fei Ru
- The Johns Hopkins School of Medicine Departments of Medicine, Baltimore, MD
| | - Hui Sun
- The Johns Hopkins School of Medicine Departments of Medicine, Baltimore, MD
| | - Jingya Wang
- AstraZeneca BioPharmaceuticals R&D Gaithersburg, MD
| | | | - Xinzhong Dong
- The Johns Hopkins School of Medicine Departments of Neuroscience, Baltimore, MD
| | - Marian Kollarik
- The Johns Hopkins School of Medicine Departments of Medicine, Baltimore, MD
| | - Brendan J Canning
- The Johns Hopkins School of Medicine Departments of Medicine, Baltimore, MD
| | - Bradley J Undem
- The Johns Hopkins School of Medicine Departments of Medicine, Baltimore, MD
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14
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Bai L, Mesgarzadeh S, Ramesh KS, Huey EL, Liu Y, Gray LA, Aitken TJ, Chen Y, Beutler LR, Ahn JS, Madisen L, Zeng H, Krasnow MA, Knight ZA. Genetic Identification of Vagal Sensory Neurons That Control Feeding. Cell 2019; 179:1129-1143.e23. [PMID: 31730854 DOI: 10.1016/j.cell.2019.10.031] [Citation(s) in RCA: 219] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/02/2019] [Accepted: 10/23/2019] [Indexed: 12/31/2022]
Abstract
Energy homeostasis requires precise measurement of the quantity and quality of ingested food. The vagus nerve innervates the gut and can detect diverse interoceptive cues, but the identity of the key sensory neurons and corresponding signals that regulate food intake remains unknown. Here, we use an approach for target-specific, single-cell RNA sequencing to generate a map of the vagal cell types that innervate the gastrointestinal tract. We show that unique molecular markers identify vagal neurons with distinct innervation patterns, sensory endings, and function. Surprisingly, we find that food intake is most sensitive to stimulation of mechanoreceptors in the intestine, whereas nutrient-activated mucosal afferents have no effect. Peripheral manipulations combined with central recordings reveal that intestinal mechanoreceptors, but not other cell types, potently and durably inhibit hunger-promoting AgRP neurons in the hypothalamus. These findings identify a key role for intestinal mechanoreceptors in the regulation of feeding.
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15
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Christie S, O'Rielly R, Li H, Nunez-Salces M, Wittert GA, Page AJ. Modulatory effect of methanandamide on gastric vagal afferent satiety signals depends on nutritional status. J Physiol 2020; 598:2169-2182. [PMID: 32237243 DOI: 10.1113/jp279449] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 03/25/2020] [Indexed: 12/18/2022] Open
Abstract
SIGNIFICANCE STATEMENT Gastric vagal afferent responses to tension are dampened in high fat diet-induced obesity. Endocannabinoids are known to dose-dependently inhibit and excite gastric vagal afferents but their effect on gastric vagal afferents in diet-induced obesity are unknown. In individual gastric vagal afferent neurons of diet-induced obese mice the co-expression of components of the endocannabinoid system, including CB1, GHSR, TRPV1 and FAAH, was increased compared with lean mice. In high fat diet-induced obese mice, methanandamide only inhibited gastric vagal afferent responses to tension, possibly due to the observed change in the balance of receptors, hormones and breakdown enzymes in this system. Collectively, these data suggest that endocannabinoid signalling, by gastric vagal afferents, is altered in diet-induced obesity which may impact satiety and gastrointestinal function. ABSTRACT Gastric vagal afferents (GVAs) play a role in appetite regulation. The endocannabinoid anandamide (AEA) dose-dependently inhibits and excites tension-sensitive GVAs. However, it is also known that high fat diet (HFD) feeding alters GVA responses to stretch. The aim of this study was to determine the role of AEA in GVA signalling in lean and HFD-induced obese mice. Male C57BL/6 mice were fed (12 weeks) a standard laboratory diet (SLD) or HFD. Protein and mRNA expression of components of the cannabinoid system was determined in individual GVA cell bodies and the gastric mucosa. An in vitro GVA preparation was used to assess the effect of methanandamide (mAEA) on tension-sensitive GVAs and the second messenger pathways involved. In individual GVA cell bodies, cannabinoid 1 (CB1) and ghrelin (GHSR) receptor mRNA was higher in HFD mice than SLD mice. Conversely, gastric mucosal AEA and ghrelin protein levels were lower in HFD mice than SLD mice. In SLD mice, mAEA exerted dose-dependent inhibitory and excitatory effects on tension-sensitive GVAs. Only an inhibitory effect of mAEA was observed in HFD mice. The excitatory effect of mAEA was dependent on CB1, transient receptor potential vanilloid 1 (TRPV1) and the protein kinase C. Conversely, the inhibitory effect was dependent on CB1, growth hormone secretagogue receptor, TRPV1 and the protein kinase A. Endocannabinoids, acting through CB1 and TRPV1, have a pivotal role in modulating GVA satiety signals depending on the second messenger pathway utilised. In HFD mice only an inhibitory effect was observed. These changes may contribute to the development and/or maintenance of obesity.
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Affiliation(s)
- Stewart Christie
- Vagal Afferent Research Group, Adelaide Medical School, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Rebecca O'Rielly
- Vagal Afferent Research Group, Adelaide Medical School, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Hui Li
- Vagal Afferent Research Group, Adelaide Medical School, University of Adelaide, Adelaide, SA, 5005, Australia.,Nutrition, Diabetes & Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, 5000, Australia
| | - Maria Nunez-Salces
- Vagal Afferent Research Group, Adelaide Medical School, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Gary A Wittert
- Vagal Afferent Research Group, Adelaide Medical School, University of Adelaide, Adelaide, SA, 5005, Australia.,Nutrition, Diabetes & Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, 5000, Australia
| | - Amanda J Page
- Vagal Afferent Research Group, Adelaide Medical School, University of Adelaide, Adelaide, SA, 5005, Australia.,Nutrition, Diabetes & Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, 5000, Australia
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16
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Kim SH, Hadley SH, Maddison M, Patil M, Cha B, Kollarik M, Taylor-Clark TE. Mapping of Sensory Nerve Subsets within the Vagal Ganglia and the Brainstem Using Reporter Mice for Pirt, TRPV1, 5-HT3, and Tac1 Expression. eNeuro 2020; 7:ENEURO. [PMID: 32060036 DOI: 10.1523/ENEURO.0494-19.2020] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/09/2020] [Accepted: 01/30/2020] [Indexed: 11/21/2022] Open
Abstract
Vagal afferent sensory nerves, originating in jugular and nodose ganglia, are composed of functionally distinct subsets whose activation evokes distinct thoracic and abdominal reflex responses. We used Cre-expressing mouse strains to identify specific vagal afferent populations and map their central projections within the brainstem. We show that Pirt is expressed in virtually all vagal afferents; whereas, 5-HT3 is expressed only in nodose neurons, with little expression in jugular neurons. Transient receptor potential vanilloid 1 (TRPV1), the capsaicin receptor, is expressed in a subset of small nodose and jugular neurons. Tac1, the gene for tachykinins, is expressed predominantly in jugular neurons, some of which also express TRPV1. Vagal fibers project centrally to the nucleus tractus solitarius (nTS), paratrigeminal complex, area postrema, and to a limited extent the dorsal motor nucleus of the vagus. nTS subnuclei preferentially receive projections by specific afferent subsets, with TRPV1+ fibers terminating in medial and dorsal regions predominantly caudal of obex, whereas TRPV1− fibers terminate in ventral and lateral regions throughout the rostral–caudal aspect of the medulla. Many vagal Tac1+ afferents (mostly derived from the jugular ganglion) terminate in the nTS. The paratrigeminal complex was the target of multiple vagal afferent subsets. Importantly, lung-specific TRPV1+ and Tac1+ afferent terminations were restricted to the caudal medial nTS, with no innervation of other medulla regions. In summary, this study identifies the specific medulla regions innervated by vagal afferent subsets. The distinct terminations provide a neuroanatomic substrate for the diverse range of reflexes initiated by vagal afferent activation.
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17
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Blanke EN, Stella SL, Ruiz-Velasco V, Holmes GM. Purinergic receptor expression and function in rat vagal sensory neurons innervating the stomach. Neurosci Lett 2019; 706:182-188. [PMID: 31085293 DOI: 10.1016/j.neulet.2019.05.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/30/2019] [Accepted: 05/10/2019] [Indexed: 12/23/2022]
Abstract
The nodose ganglion (NG) is the main parasympathetic ganglion conveying sensory signals to the CNS from numerous visceral organs including digestive signals such as gastric distension or the release the gastrointestinal peptides. The response characteristics of NG neurons to ATP and ADP and pharmacological interrogation of purinergic receptor subtypes have been previously investigated but often in NG cells of undetermined visceral origin. In this study, we confirmed the presence of P2X3 and P2Y1 receptors and characterized P2X and P2Y responses in gastric-innervating NG neurons. Application of ATP-evoked large inward currents and cytosolic Ca2+ increases in gastric-innervating NG neurons. Despite the expression of P2Y1 receptors, ADP elicited only minor modulation of voltage-gated Ca2+ channels. Considering the sensitivity of NG neurons to comorbidities associated with disease or neural injury, purinergic modulation of gastric NG neurons in disease- or injury-states is worthy of further investigation.
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Affiliation(s)
- Emily N Blanke
- Department of Neural & Behavioral Sciences, Penn State University College of Medicine, 500 University Dr., MC H109, Hershey, PA, 17033, USA
| | - Salvatore L Stella
- Department of Neural & Behavioral Sciences, Penn State University College of Medicine, 500 University Dr., MC H109, Hershey, PA, 17033, USA
| | - Victor Ruiz-Velasco
- Department of Anesthesiology and Perioperative Medicine, Penn State University College of Medicine, USA
| | - Gregory M Holmes
- Department of Neural & Behavioral Sciences, Penn State University College of Medicine, 500 University Dr., MC H109, Hershey, PA, 17033, USA.
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18
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Kentish SJ, Hatzinikolas G, Li H, Frisby CL, Wittert GA, Page AJ. Time-Restricted Feeding Prevents Ablation of Diurnal Rhythms in Gastric Vagal Afferent Mechanosensitivity Observed in High-Fat Diet-Induced Obese Mice. J Neurosci 2018; 38:5088-95. [PMID: 29760179 DOI: 10.1523/JNEUROSCI.0052-18.2018] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/23/2018] [Accepted: 04/20/2018] [Indexed: 12/20/2022] Open
Abstract
Mechanosensitive gastric vagal afferents (GVAs) are involved in the regulation of food intake. GVAs exhibit diurnal rhythmicity in their response to food-related stimuli, allowing time of day-specific satiety signaling. This diurnal rhythmicity is ablated in high-fat-diet (HFD)-induced obesity. Time-restricted feeding (TRF) has a strong influence on peripheral clocks. This study aimed to determine whether diurnal patterns in GVA mechanosensitivity are entrained by TRF. Eight-week-old male C57BL/6 mice (N = 256) were fed a standard laboratory diet (SLD) or HFD for 12 weeks. After 4 weeks of diet acclimatization, the mice were fed either ad libitum or only during the light phase [Zeitgeber time (ZT) 0-12] or dark phase (ZT12-24) for 8 weeks. A subgroup of mice from all conditions (n = 8/condition) were placed in metabolic cages. After 12 weeks, ex vivo GVA recordings were taken at 3 h intervals starting at ZT0. HFD mice gained more weight than SLD mice. TRF did not affect weight gain in the SLD mice, but decreased weight gain in the HFD mice regardless of the TRF period. In SLD mice, diurnal rhythms in food intake were inversely associated with diurnal rhythmicity of GVA mechanosensitivity. These diurnal rhythms were entrained by the timing of food intake. In HFD mice, diurnal rhythms in food intake and diurnal rhythmicity of GVA mechanosensitivity were dampened. Loss of diurnal rhythmicity in HFD mice was abrogated by TRF. In conclusion, diurnal rhythmicity in GVA responses to food-related stimuli can be entrained by food intake. TRF prevents the loss of diurnal rhythmicity that occurs in HFD-induced obesity.SIGNIFICANCE STATEMENT Diurnal control of food intake is vital for maintaining metabolic health. Diet-induced obesity is associated with strong diurnal changes in food intake. Vagal afferents are involved in regulation of feeding behavior, particularly meal size, and exhibit diurnal fluctuations in mechanosensitivity. These diurnal fluctuations in vagal afferent mechanosensitivity are lost in diet-induced obesity. This study provides evidence that time-restricted feeding entrains diurnal rhythmicity in vagal afferent mechanosensitivity in lean and high-fat-diet (HFD)-induced obese mice and, more importantly, prevents the loss of rhythmicity in HFD-induced obesity. These data have important implications for the development of strategies to treat obesity.
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19
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Abstract
The upper gastrointestinal tract plays an important role in sensing the arrival, amount and chemical composition of a meal. Ingestion of a meal triggers a number of sensory signals in the gastrointestinal tract. These include the response to mechanical stimulation (e.g., gastric distension), from the presence of food in the gut, and the interaction of various dietary nutrients with specific "taste" receptors on specialized enteroendocrine cells in the small intestine culminating in the release of gut hormones. These signals are then transmitted to the brain where they contribute to food intake regulation by modulating appetite as well as feedback control of gastrointestinal functions (e.g., gut motility). There is evidence that the sensitivity to these food related stimuli is abnormally enhanced in functional dyspepsia leading to symptoms such nausea and bloating. In addition, these gut-brain signals can modulate the signaling pathways involved in visceral pain. This review will discuss the role of gut-brain signals in appetite regulation and the role dysregulation of this system play in functional dyspepsia.
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Affiliation(s)
- Amanda J Page
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia.,South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
| | - Hui Li
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia.,South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
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20
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Klarer M, Krieger JP, Richetto J, Weber-Stadlbauer U, Günther L, Winter C, Arnold M, Langhans W, Meyer U. Abdominal Vagal Afferents Modulate the Brain Transcriptome and Behaviors Relevant to Schizophrenia. J Neurosci 2018; 38:1634-47. [PMID: 29326171 DOI: 10.1523/JNEUROSCI.0813-17.2017] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 11/25/2017] [Accepted: 12/18/2017] [Indexed: 12/26/2022] Open
Abstract
Reduced activity of vagal efferents has long been implicated in schizophrenia and appears to be responsible for diminished parasympathetic activity and associated peripheral symptoms such as low heart rate variability and cardiovascular complications in affected individuals. In contrast, only little attention has been paid to the possibility that impaired afferent vagal signaling may be relevant for the disorder's pathophysiology as well. The present study explored this hypothesis using a model of subdiaphragmatic vagal deafferentation (SDA) in male rats. SDA represents the most complete and selective vagal deafferentation method existing to date as it leads to complete disconnection of all abdominal vagal afferents while sparing half of the abdominal vagal efferents. Using next-generation mRNA sequencing, we show that SDA leads to brain transcriptional changes in functional networks annotating with schizophrenia. We further demonstrate that SDA induces a hyperdopaminergic state, which manifests itself as increased sensitivity to acute amphetamine treatment and elevated accumbal levels of dopamine and its major metabolite, 3,4-dihydroxyphenylacetic acid. Our study also shows that SDA impairs sensorimotor gating and the attentional control of associative learning, which were assessed using the paradigms of prepulse inhibition and latent inhibition, respectively. These data provide converging evidence suggesting that the brain transcriptome, dopamine neurochemistry, and behavioral functions implicated in schizophrenia are subject to visceral modulation through abdominal vagal afferents. Our findings may encourage the further establishment and use of therapies for schizophrenia that are based on vagal interventions.SIGNIFICANCE STATEMENT The present work provides a better understanding of how disrupted vagal afferent signaling can contribute to schizophrenia-related brain and behavioral abnormalities. More specifically, it shows that subdiaphragmatic vagal deafferentation (SDA) in rats leads to (1) brain transcriptional changes in functional networks related to schizophrenia, (2) increased sensitivity to dopamine-stimulating drugs and elevated dopamine levels in the nucleus accumbens, and (3) impairments in sensorimotor gating and the attentional control of associative learning. These findings may encourage the further establishment of novel therapies for schizophrenia that are based on vagal interventions.
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21
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Zhang T, Tanida M, Uchida K, Suzuki Y, Yang W, Kuda Y, Kurata Y, Tominaga M, Shibamoto T. Mouse Anaphylactic Hypotension Is Characterized by Initial Baroreflex Independent Renal Sympathoinhibition Followed by Sustained Renal Sympathoexcitation. Front Physiol 2017; 8:669. [PMID: 28936180 PMCID: PMC5594092 DOI: 10.3389/fphys.2017.00669] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 08/23/2017] [Indexed: 01/14/2023] Open
Abstract
Aim: The hemodynamic response to mouse systemic anaphylaxis is characterized by an initial hypertension followed by sustained hypotension. However, the defense mechanisms of the sympathetic nervous system against this circulatory disturbance is not known. Here, we investigated the renal sympathetic nerve activity (RSNA) response to mouse systemic anaphylaxis, along with the roles of carotid sinus baroreceptor, vagal nerves and the transient receptor potential vanilloid type 1 channel (TRPV1). Methods: Male ovalbumin-sensitized C57BL/6N mice were used under pentobarbital anesthesia. RSNA, systemic arterial pressure (SAP) and heart rate (HR) were continuously measured for 60 min after the antigen injection. Results: Within 3 min after antigen injection, RSNA decreased along with a transient increase in SAP. Thereafter, RSNA showed a progressive increase during sustained hypotension. In contrast, HR continuously increased. Sinoaortic denervation, but not vagotomy, significantly attenuated the renal sympathoexcitation and tachycardia from 30 and 46 min, respectively, after antigen. The responses of RSNA, SAP and HR to anaphylaxis were not affected by pretreatment with a TRPV1 inhibitor, capsazepine, or by genetic knockout of TRPV1. Conclusion: The mouse systemic anaphylaxis causes a biphasic RSNA response with an initial baroreflex-independent decrease and secondary increase. The antigen-induced sympathoexcitation and tachycardia at the late stage are partly mediated by carotid sinus baroreceptors. Either vagal nerve or TRPV1 does not play any significant roles in the RSNA and HR responses in anesthetized mice.
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Affiliation(s)
- Tao Zhang
- Department of Physiology II, Kanazawa Medical UniversityUchinada, Japan.,Department of Colorectal and Hernia Surgery, The Fourth Affiliated Hospital of China Medical UniversityShenyang, China
| | - Mamoru Tanida
- Department of Physiology II, Kanazawa Medical UniversityUchinada, Japan
| | - Kunitoshi Uchida
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience, National Institute for Physiological Sciences, National Institutes of Natural SciencesOkazaki, Japan.,Department of Physiological Science and Molecular Biology, Fukuoka Dental CollegeFukuoka, Japan
| | - Yoshiro Suzuki
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience, National Institute for Physiological Sciences, National Institutes of Natural SciencesOkazaki, Japan
| | - Wei Yang
- Department of Physiology II, Kanazawa Medical UniversityUchinada, Japan.,Department of Infectious Disease, The Sheng Jing Hospital of China Medical UniversityShenyang, China
| | - Yuhichi Kuda
- Department of Physiology II, Kanazawa Medical UniversityUchinada, Japan
| | - Yasutaka Kurata
- Department of Physiology II, Kanazawa Medical UniversityUchinada, Japan
| | - Makoto Tominaga
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience, National Institute for Physiological Sciences, National Institutes of Natural SciencesOkazaki, Japan
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22
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Abstract
The vagal link between the gastrointestinal tract and the central nervous system (CNS) has numerous vital functions for maintaining homeostasis. The regulation of energy balance is one which is attracting more and more attention due to the potential for exploiting peripheral hormonal targets as treatments for conditions such as obesity. While physiologically, this system is well tuned and demonstrated to be effective in the regulation of both local function and promoting/terminating food intake the neural connection represents a susceptible pathway for disruption in various disease states. Numerous studies have revealed that obesity in particularly is associated with an array of modifications in vagal afferent function from changes in expression of signaling molecules to altered activation mechanics. In general, these changes in vagal afferent function in obesity further promote food intake instead of the more desirable reduction in food intake. It is essential to gain a comprehensive understanding of the mechanisms responsible for these detrimental effects before we can establish more effective pharmacotherapies or lifestyle strategies for the treatment of obesity and the maintenance of weight loss.
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Affiliation(s)
- A J Page
- Centre for Nutrition and Gastrointestinal Disease, Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia.,Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.,Department of Gastroenterology and Hepatology, Royal Adelaide Hospital, Adelaide, SA, Australia
| | - S J Kentish
- Centre for Nutrition and Gastrointestinal Disease, Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia.,Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.,School of Medicine, University of Queensland, St Lucia, QLD, Australia
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23
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Edwards A, Abizaid A. Clarifying the Ghrelin System's Ability to Regulate Feeding Behaviours Despite Enigmatic Spatial Separation of the GHSR and Its Endogenous Ligand. Int J Mol Sci 2017; 18:E859. [PMID: 28422060 DOI: 10.3390/ijms18040859] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 04/04/2017] [Accepted: 04/11/2017] [Indexed: 12/23/2022] Open
Abstract
Ghrelin is a hormone predominantly produced in and secreted from the stomach. Ghrelin is involved in many physiological processes including feeding, the stress response, and in modulating learning, memory and motivational processes. Ghrelin does this by binding to its receptor, the growth hormone secretagogue receptor (GHSR), a receptor found in relatively high concentrations in hypothalamic and mesolimbic brain regions. While the feeding and metabolic effects of ghrelin can be explained by the effects of this hormone on regions of the brain that have a more permeable blood brain barrier (BBB), ghrelin produced within the periphery demonstrates a limited ability to reach extrahypothalamic regions where GHSRs are expressed. Therefore, one of the most pressing unanswered questions plaguing ghrelin research is how GHSRs, distributed in brain regions protected by the BBB, are activated despite ghrelin’s predominant peripheral production and poor ability to transverse the BBB. This manuscript will describe how peripheral ghrelin activates central GHSRs to encourage feeding, and how central ghrelin synthesis and ghrelin independent activation of GHSRs may also contribute to the modulation of feeding behaviours.
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24
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Huizinga JD. Commentary: Phase-amplitude coupling at the organism level: The amplitude of spontaneous alpha rhythm fluctuations varies with the phase of the infra-slow gastric basal rhythm. Front Neurosci 2017; 11:102. [PMID: 28303088 PMCID: PMC5332408 DOI: 10.3389/fnins.2017.00102] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 02/17/2017] [Indexed: 01/09/2023] Open
Affiliation(s)
- Jan D Huizinga
- Department of Medicine, Farncombe Family Digestive Health Research Institute, McMaster University Hamilton, ON, Canada
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25
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Wang EM, Li WT, Yan XJ, Chen X, Liu Q, Feng CC, Cao ZJ, Fang JY, Chen SL. Vagal afferent-dependent cholecystokinin modulation of visceral pain requires central amygdala NMDA-NR2B receptors in rats. Neurogastroenterol Motil 2015. [PMID: 26197883 DOI: 10.1111/nmo.12633] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Cholecystokinin (CCK), a gut hormone that is released during feeding, exerts gastrointestinal effects in part through vagal pathway. It is reported to be a potential trigger for increased postprandial visceral sensitivity in healthy subjects and, especially in patients with irritable bowel syndrome. NR2B-containing N-methyl-d-aspartate (NMDA) receptors in the central amygdala (CeA) participate in pain modulation. Systemically administered CCK activates the CeA-innervating neurons. Here, we investigated whether CCK modulation of visceral sensitivity is mediated through CeA NMDA-NR2B receptors and whether this modulation involves vagal pathway. METHODS We first examined the visceromotor response (VMR) to colorectal distention (CRD) following i.p. injection of CCK octapeptide (CCK-8) in a rat model. Next, the NR2B antagonist ifenprodil and the NR2A antagonist NVP-AAM077 were microinjected into the CeA before systemic CCK injection. NR2B phosphorylation was detected by Western blot. To down-regulate NR2B gene expression, NR2B-specific small interfering RNA (siRNA) was delivered into CeA neurons by electroporation. In addition, the effects of functional deafferentation by perivagal application of capsaicin and pretreatment with the CCK1 receptor antagonist devazepide were investigated. KEY RESULTS CCK-8 increased VMR to CRD in a dose-dependent manner. This effect was blunted by intra-CeA administration of ifenprodil (but not NVP-AAM077) and was accompanied by phosphorylation of NR2B subunits in the CeA. CCK failed to increase VMR to CRD in NR2B siRNA-treated rats. Perivagal capsaicin application and pretreatment with devazepide prevented CCK-induced pronociception and CeA NR2B phosphorylation. CONCLUSIONS & INFERENCES The pronociception induced by systemic CCK, which is vagal afferent-dependent, requires activation of CeA NMDA-NR2B receptors.
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Affiliation(s)
- E M Wang
- Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, Shanghai, China
| | - W T Li
- Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, Shanghai, China
| | - X J Yan
- Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, Shanghai, China
| | - X Chen
- Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, Shanghai, China
| | - Q Liu
- Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, Shanghai, China
| | - C C Feng
- Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, Shanghai, China
| | - Z J Cao
- Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, Shanghai, China
| | - J Y Fang
- Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, Shanghai, China
| | - S L Chen
- Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, Shanghai, China
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26
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Li JN, Li XL, He J, Wang JX, Zhao M, Liang XB, Zhao SY, Ma MN, Liu Y, Wang YB, Chen H, Qiao GF, Li BY. Sex- and afferent-specific differences in histamine receptor expression in vagal afferents of rats: A potential mechanism for sexual dimorphism in prevalence and severity of asthma. Neuroscience 2015; 303:166-77. [PMID: 26141840 DOI: 10.1016/j.neuroscience.2015.06.049] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 06/22/2015] [Accepted: 06/23/2015] [Indexed: 10/23/2022]
Abstract
The incidence of asthma is more common in boys than in girls during the childhood, and more common in premenopausal female than age-matched males. Our previous study demonstrated a gender difference in histamine-mediated neuroexcitability in nodose ganglia neurons (NGNs), highlighting a possibility of histamine-mediated gender difference in asthma via visceral afferent function. In the present study, we aimed to explore the gender difference in expression profiles of histamine receptors (HRs) in nodose ganglia (NG) and individual identified NGNs to provide deeper insights into the mechanisms involved in sexual dimorphism of asthma. Western-blot and SYBR green RT-PCR showed that H2R and H3R were highly expressed in NG of females compared with males and downregulated in ovariectomized females. H1R was equally expressed in NG of both sexes and not altered by ovariectomy. Furthermore, this highly expressive H2R and H3R were distributed in both myelinated and unmyelinated NGNs isolated from adult female rats by immunofluorescence and single-cell RT-PCR. H3R widely distributed in all tested neuron subtypes and its expression did not show significant difference among neuron subtypes. H2R was widely and highly expressed in low-threshold and sex-specific subpopulation of myelinated Ah-types compared with myelinated A- and unmyelinated C-type NGNs. Unexpectedly, weak expression of H1R was detected in both myelinated and unmyelinated NGNs by immunofluorescence, which was further confirmed by single-cell RT-PCR. Our results suggest that the sexual dimorphism in the expression of H2R and H3R in vagal afferents very likely contributes, at least partially, to the gender difference in prevalence and severity of asthma.
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Affiliation(s)
- J N Li
- Department of Pharmacology, Harbin Medical University, Harbin, China
| | - X L Li
- Department of Pharmacology, Harbin Medical University, Harbin, China; Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Harbin Medical University, Harbin, China
| | - J He
- Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Harbin Medical University, Harbin, China
| | - J X Wang
- Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Harbin Medical University, Harbin, China
| | - M Zhao
- Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Harbin Medical University, Harbin, China
| | - X B Liang
- Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Harbin Medical University, Harbin, China
| | - S Y Zhao
- Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Harbin Medical University, Harbin, China
| | - M N Ma
- Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Harbin Medical University, Harbin, China
| | - Y Liu
- Department of Pharmacology, Harbin Medical University, Harbin, China
| | - Y B Wang
- Department of Cerebral Surgery, Harbin Municipal First Hospital, Harbin, China
| | - H Chen
- Riley Heart Research Center, Division of Pediatric Cardiology, Herman B. Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, USA
| | - G F Qiao
- Department of Pharmacology, Harbin Medical University, Harbin, China; Key Laboratory of Cardiovascular Medicine Research, Ministry of Education, Harbin Medical University, Harbin, China.
| | - B Y Li
- Department of Pharmacology, Harbin Medical University, Harbin, China.
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Zhuang J, Zhao L, Zang N, Xu F. Prenatal nicotinic exposure augments cardiorespiratory responses to activation of bronchopulmonary C-fibers. Am J Physiol Lung Cell Mol Physiol 2015; 308:L922-30. [PMID: 25747962 DOI: 10.1152/ajplung.00241.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 03/01/2015] [Indexed: 12/26/2022] Open
Abstract
Rat pups prenatally exposed to nicotine (PNE) present apneic (lethal ventilatory arrest) responses during severe hypoxia. To clarify whether these responses are of central origin, we tested PNE effects on ventilation and diaphragm electromyography (EMGdi) during hypoxia in conscious rat pups. PNE produced apnea (lethal ventilatory arrest) identical to EMGdi silencing during hypoxia, indicating a central origin of this apneic response. We further asked whether PNE would sensitize bronchopulmonary C-fibers (PCFs), a key player in generating central apnea, with increase of the density and transient receptor potential cation channel subfamily V member 1 (TRPV1) expression of C-fibers/neurons in the nodose/jugular (N/J) ganglia and neurotrophic factors in the airways and lungs. We compared 1) ventilatory and pulmonary C-neural responses to right atrial bolus injection of capsaicin (CAP, 0.5 μg/kg), 2) bronchial substance P-immunoreactive (SP-IR) fiber density, 3) gene and protein expressions of TRPV1 in the ganglia, and 4) nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) protein in bronchoalveolar lavage fluid (BALF) and TrkA and TrkB genes in the ganglia between control and PNE pups. PNE markedly strengthened the PCF-mediated apneic response to CAP via increasing pulmonary C-neural sensitivity. PNE also enhanced bronchial SP-IR fiber density and N/J ganglia neural TRPV1 expression associated with increased gene expression of TrkA in the N/G ganglia and decreased NGF and BDNF in BALF. Our results suggest that PNE enhances PCF sensitivity likely through increasing PCF density and TRPV1 expression via upregulation of neural TrkA and downregulation of pulmonary BDNF, which may contribute to the PNE-promoted central apnea (lethal ventilatory arrest) during hypoxia.
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Affiliation(s)
- Jianguo Zhuang
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Lei Zhao
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Na Zang
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Fadi Xu
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
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McDougall SJ, Münzberg H, Derbenev AV, Zsombok A. Central control of autonomic functions in health and disease. Front Neurosci 2015; 8:440. [PMID: 25620907 PMCID: PMC4288135 DOI: 10.3389/fnins.2014.00440] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 12/15/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Stuart J McDougall
- Florey Institute of Neuroscience and Mental Health, University of Melbourne Parkville, VIC, Australia
| | - Heike Münzberg
- Pennington Biomedical Research Center, Louisiana State University Baton Rouge, LA, USA
| | | | - Andrea Zsombok
- Department of Physiology, Tulane University New Orleans, LA, USA
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Abstract
Activation of pulmonary C-fibers can reflexively decrease heart rate, blood pressure, and peripheral vascular resistance. However, the effects of these afferents on microvascular tone remain incompletely understood. In this study, we examined the effects of these afferents on microvascular tone in a striated muscle vascular bed. The right cremaster muscle in pentobarbital-anesthetized rats with intact circulation and innervation was suspended in a tissue bath, and diameters of small arterioles were measured by intravital video microscopy. Stimulation of pulmonary C-fibers by injecting capsaicin (5 μg/kg) or phenylbiguanide (20 μg/kg) into the right atrium dilated small arterioles and decreased blood pressure and heart rate. The effects persisted when the cervical vagus nerves were cooled to 5 to 7°C (blocking myelinated fibers), but were prevented by cooling to 0°C (blocking C-fibers and myelinated fibers), by cutting the genital femoral nerve (GFN) supplying the cremaster to block the nerve supply to the muscle, or by adding 6-hydroxydopamine to the bathing medium to selectively block sympathetic effects by depleting norepinephrine from adrenergic nerve terminals. Our results show that stimulation of pulmonary C-fibers reflexively dilates small arterioles in striated muscle by a mechanism that could involve withdrawal of sympathetic adrenergic tone. In conclusion, pulmonary C-fibers can exert an inhibitory influence on neural tone of the microcirculation at an important site where microvascular resistance and tissue blood flow are regulated.
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Affiliation(s)
- Andrew M Roberts
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky; Department of Pediatrics, School of Medicine, University of Louisville, Louisville, Kentucky;
| | - Jerry Yu
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky; Department of Medicine, School of Medicine, University of Louisville, Louisville, Kentucky; and Robley Rex Veterans Administration Medical Center, Louisville, Kentucky
| | - Irving G Joshua
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky
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Liu C, Bookout AL, Lee S, Sun K, Jia L, Lee C, Udit S, Deng Y, Scherer PE, Mangelsdorf DJ, Gautron L, Elmquist JK. PPARγ in vagal neurons regulates high-fat diet induced thermogenesis. Cell Metab 2014; 19:722-30. [PMID: 24703703 PMCID: PMC4046333 DOI: 10.1016/j.cmet.2014.01.021] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 11/05/2013] [Accepted: 01/29/2014] [Indexed: 12/26/2022]
Abstract
The vagus nerve innervates visceral organs providing a link between key metabolic cues and the CNS. However, it is not clear whether vagal neurons can directly respond to changing lipid levels and whether altered "lipid sensing" by the vagus nerve regulates energy balance. In this study, we systematically profiled the expression of all known nuclear receptors in laser-captured nodose ganglion (NG) neurons. In particular, we found PPARγ expression was reduced by high-fat-diet feeding. Deletion of PPARγ in Phox2b neurons promoted HFD-induced thermogenesis that involved the reprograming of white adipocyte into a brown-like adipocyte cell fate. Finally, we showed that PPARγ in NG neurons regulates genes necessary for lipid metabolism and those that are important for synaptic transmission. Collectively, our findings provide insights into how vagal afferents survey peripheral metabolic cues and suggest that the reduction of PPARγ in NG neurons may serve as a protective mechanism against diet-induced weight gain.
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Affiliation(s)
- Chen Liu
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Angie L Bookout
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Syann Lee
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Kai Sun
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Lin Jia
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Charlotte Lee
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Swalpa Udit
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Yingfeng Deng
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Philipp E Scherer
- Touchstone Diabetes Center, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - David J Mangelsdorf
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Laurent Gautron
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
| | - Joel K Elmquist
- Division of Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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Li H, Kentish SJ, Kritas S, Young RL, Isaacs NJ, O'Donnell TA, Blackshaw LA, Wittert GA, Page AJ. Modulation of murine gastric vagal afferent mechanosensitivity by neuropeptide W. Acta Physiol (Oxf) 2013; 209:179-91. [PMID: 23927541 DOI: 10.1111/apha.12154] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/09/2013] [Accepted: 07/31/2013] [Indexed: 12/22/2022]
Abstract
AIM Neuropeptide W (NPW) is an endogenous ligand for the receptors GPR7 and GPR8 and is involved in central regulation of energy homeostasis. NPW in the periphery is found in gastric gastrin (G) cells. In the stomach, energy intake is influenced by vagal afferent signals, so we aimed to determine the effect of NPW on mechanosensitive gastric vagal afferents under different feeding conditions. METHODS Female C57BL/6 mice (N > 10 per group) were fed a standard laboratory diet (SLD), high-fat diet (HFD) or were food restricted. The relationship between NPW immunopositive cells and gastric vagal afferent endings was determined by anterograde tracing and NPW immunohistochemistry. An in vitro gastro-oesophageal preparation was used to determine the functional effects of NPW on gastric vagal afferents. Expression of NPW in the gastric mucosa and GPR7 in whole nodose ganglia was determined by quantitative RT-PCR (QRT-PCR). The expression of GPR7 in gastric vagal afferent neurones was determined by retrograde tracing and QRT-PCR. RESULTS Neuropeptide W immunoreactive cells were found in close proximity to traced vagal afferents. NPW selectively inhibited responses of gastric vagal tension receptors to stretch in SLD but not HFD or fasted mice. In the nodose ganglia, GPR7 mRNA was specifically expressed in gastric vagal afferent neurones. In fasted mice gastric mucosal NPW and nodose GPR7, mRNA was reduced compared with SLD. A HFD had no effect on gastric NPW mRNA, but down-regulated nodose GPR7 expression. CONCLUSION Neuropeptide W modulates gastric vagal afferent activity, but the effect is dynamic and related to feeding status.
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Affiliation(s)
- H. Li
- Nerve-Gut Research Laboratory; University of Adelaide; Adelaide; Australia
| | - S. J. Kentish
- Nerve-Gut Research Laboratory; University of Adelaide; Adelaide; Australia
| | - S. Kritas
- Women's & Children's Hospital; University of Adelaide; Adelaide; Australia
| | | | - N. J. Isaacs
- Nerve-Gut Research Laboratory; University of Adelaide; Adelaide; Australia
| | | | - L. A. Blackshaw
- Wingate Institute of Neurogastroenterology; Blizard Institute; Barts and The London School of Medicine & Dentistry; Queen Mary, University of London; London; UK
| | - G. A. Wittert
- Nerve-Gut Research Laboratory; University of Adelaide; Adelaide; Australia
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Zielinski MR, Dunbrasky DL, Taishi P, Souza G, Krueger JM. Vagotomy attenuates brain cytokines and sleep induced by peripherally administered tumor necrosis factor-α and lipopolysaccharide in mice. Sleep 2013; 36:1227-38, 1238A. [PMID: 23904683 DOI: 10.5665/sleep.2892] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
STUDY OBJECTIVE Systemic tumor necrosis factor-α (TNF-α) is linked to sleep and sleep altering pathologies in humans. Evidence from animals indicates that systemic and brain TNF-α have a role in regulating sleep. In animals, TNF-α or lipopolysaccharide (LPS) enhance brain pro-inflammatory cytokine expression and sleep after central or peripheral administration. Vagotomy blocks enhanced sleep induced by systemic TNF-α and LPS in rats, suggesting that vagal afferent stimulation by TNF-α enhances pro-inflammatory cytokines in sleep-related brain areas. However, the effects of systemic TNF-α on brain cytokine expression and mouse sleep remain unknown. DESIGN We investigated the role of vagal afferents on brain cytokines and sleep after systemically applied TNF-α or LPS in mice. MEASUREMENTS AND RESULTS Spontaneous sleep was similar in vagotomized and sham-operated controls. Vagotomy attenuated TNF-α- and LPS-enhanced non-rapid eye movement sleep (NREMS); these effects were more evident after lower doses of these substances. Vagotomy did not affect rapid eye movement sleep responses to these substances. NREMS electroencephalogram delta power (0.5-4 Hz range) was suppressed after peripheral TNF-α or LPS injections, although vagotomy did not affect these responses. Compared to sham-operated controls, vagotomy did not affect liver cytokines. However, vagotomy attenuated interleukin-1 beta (IL-1β) and TNF-α mRNA brain levels after TNF-α, but not after LPS, compared to the sham-operated controls. CONCLUSIONS We conclude that vagal afferents mediate peripheral TNF-α-induced brain TNF-α and IL-1β mRNA expressions to affect sleep. We also conclude that vagal afferents alter sleep induced by peripheral pro-inflammatory stimuli in mice similar to those occurring in other species.
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Affiliation(s)
- Mark R Zielinski
- Sleep and Performance Research Center, Washington State University, Spokane, WA 99210-1495, USA
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Andresen MC, Fawley JA, Hofmann ME. Peptide and lipid modulation of glutamatergic afferent synaptic transmission in the solitary tract nucleus. Front Neurosci 2013; 6:191. [PMID: 23335875 PMCID: PMC3541483 DOI: 10.3389/fnins.2012.00191] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 12/17/2012] [Indexed: 12/21/2022] Open
Abstract
The brainstem nucleus of the solitary tract (NTS) holds the first central neurons in major homeostatic reflex pathways. These homeostatic reflexes regulate and coordinate multiple organ systems from gastrointestinal to cardiopulmonary functions. The core of many of these pathways arise from cranial visceral afferent neurons that enter the brain as the solitary tract (ST) with more than two-thirds arising from the gastrointestinal system. About one quarter of ST afferents have myelinated axons but the majority are classed as unmyelinated C-fibers. All ST afferents release the fast neurotransmitter glutamate with remarkably similar, high-probability release characteristics. Second order NTS neurons receive surprisingly limited primary afferent information with one or two individual inputs converging on single second order NTS neurons. A- and C-fiber afferents never mix at NTS second order neurons. Many transmitters modify the basic glutamatergic excitatory postsynaptic current often by reducing glutamate release or interrupting terminal depolarization. Thus, a distinguishing feature of ST transmission is presynaptic expression of G-protein coupled receptors for peptides common to peripheral or forebrain (e.g., hypothalamus) neuron sources. Presynaptic receptors for angiotensin (AT1), vasopressin (V1a), oxytocin, opioid (MOR), ghrelin (GHSR1), and cholecystokinin differentially control glutamate release on particular subsets of neurons with most other ST afferents unaffected. Lastly, lipid-like signals are transduced by two key ST presynaptic receptors, the transient receptor potential vanilloid type 1 and the cannabinoid receptor that oppositely control glutamate release. Increasing evidence suggests that peripheral nervous signaling mechanisms are repurposed at central terminals to control excitation and are major sites of signal integration of peripheral and central inputs particularly from the hypothalamus.
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Affiliation(s)
- Michael C Andresen
- Department of Physiology and Pharmacology, Oregon Health and Science University Portland, OR, USA
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Abstract
Stimulation of the vagus nerve has been previously reported to promote neural plasticity and neurogenesis in the brain. Several studies also revealed plastic changes in the spinal cord after injuries to somatosensory nerves originating from both the brachial and lumbo-sacral plexuses. However, the neurogenic responses of the brain to the injury of the viscerosensory innervation are not as yet well understood. In the present study, we investigated whether cells in the dentate gyrus of the hippocampus respond to a chemical and physical damage to the vagus nerve in the adult rat. Intraperitoneal capsaicin administration was used to damage non-myelinated vagal afferents while subdiaphragmatic vagotomy was used to damage both the myelinated and non-myelinated vagal afferents. The 5-bromo-2-deoxyuridine (BrdU) incorporation together with cell-specific markers was used to study neural proliferation in subgranular zone, granule cell layer, molecular layer and hilus of the dentate gyrus. Microglia activation was determined by quantifying changes in the intensity of fluorescent staining with a primary antibody against ionizing calcium adapter-binding molecule 1. Results revealed that vagotomy decreased BrdU incorporation in the hilus 15 days after injury compared to the capsaicin group. Capsaicin administration decreased BrdU incorporation in the granular cell layer 60 days after the treatment. Capsaicin decreased the number of doublecortin-expressing cells in the dentate gyrus, whereas vagotomy did not alter the expression of doublecortin in the hippocampus. Both the capsaicin- and the vagotomy-induced damage to the vagus nerve decreased microglia activation in the hippocampus at 15 days after the injury. At 30 days post injury, capsaicin-treated and vagotomized rats revealed significantly more activated microglia. Our findings show that damage to the subdiaphragmatic vagus in adult rats is followed by microglia activation and long-lasting changes in the dentate gyrus, leading to alteration of neurogenesis.
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Affiliation(s)
- Giulia Ronchi
- Department of Clinical and Biological Sciences, University of Turin, Turin 10043, Italy
- Neuroscience Institute of the “Cavalieri Ottolenghi” Foundation (NICO), University of Turin, Turin 10043, Italy
| | - Vitaly Ryu
- Programs in Neuroscience and Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
| | - Michele Fornaro
- Department of Anatomy, Midwestern University, Downers Grove, IL60515, USA
| | - Krzysztof Czaja
- Programs in Neuroscience and Department of Veterinary and Comparative Anatomy, Pharmacology, and Physiology, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
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Blackshaw LA, Page AJ, Young RL. Metabotropic glutamate receptors as novel therapeutic targets on visceral sensory pathways. Front Neurosci 2011; 5:40. [PMID: 21472028 PMCID: PMC3066463 DOI: 10.3389/fnins.2011.00040] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 03/14/2011] [Indexed: 01/07/2023] Open
Abstract
Metabotropic glutamate receptors (mGluR) have a diverse range of structures and molecular coupling mechanisms. There are eight mGluR subtypes divided into three major groups. Group I (mGluR1 and 5) is excitatory; groups II (mGluR2 and 3) and III (mGluR 4, 6, and 7) are inhibitory. All mGluR are found in the mammalian nervous system but some are absent from sensory neurons. The focus here is on mGluR in sensory pathways from the viscera, where they have been explored as therapeutic targets. Group I mGluR are activated by endogenous glutamate or constitutively active without agonist. Constitutive activity can be exploited by inverse agonists to reduce neuronal excitability without synaptic input. This is promising for reducing activation of nociceptive afferents and pain using mGluR5 negative allosteric modulators. Many inhibitory mGluR are also expressed in visceral afferents, many of which markedly reduce excitability. Their role in visceral pain remains to be determined, but they have shown promise in inhibition of the triggering of gastro-esophageal reflux, via an action on mechanosensory gastric afferents. The extent of reflux inhibition is limited, however, and may not reach a clinically useful level. On the other hand, negative modulation of mGluR5 has very potent actions on reflux inhibition, which has produced the most likely candidates so far as therapeutic drugs. These act probably outside the central nervous system, and may therefore provide a generous therapeutic window. There are many unanswered questions about mGluR along visceral afferent pathways, the answers to which may reveal many more therapeutic candidates.
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Affiliation(s)
- L Ashley Blackshaw
- Nerve Gut Research Laboratory, Department of Gastroenterology and Hepatology, Hanson Institute, Royal Adelaide Hospital Adelaide, SA, Australia
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Abstract
The detection of nutrients in the gastrointestinal (GI) tract is of fundamental significance to the control of motility, glycemia and energy intake, and yet we barely know the most fundamental aspects of this process. This is in stark contrast to the mechanisms underlying the detection of lingual taste, which have been increasingly well characterized in recent years, and which provide an excellent starting point for characterizing nutrient detection in the intestine. This review focuses on the form and function of sweet taste transduction mechanisms identified in the intestinal tract; it does not focus on sensors for fatty acids or proteins. It examines the intestinal cell types equipped with sweet taste transduction molecules in animals and humans, their location, and potential signals that transduce the presence of nutrients to neural pathways involved in reflex control of GI motility.
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Affiliation(s)
- Richard L Young
- Discipline of Medicine, School of Medicine, University of Adelaide Adelaide, SA, Australia
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Li Y, Wu X, Zhou S, Owyang C. Low-affinity CCK-A receptors are coexpressed with leptin receptors in rat nodose ganglia: implications for leptin as a regulator of short-term satiety. Am J Physiol Gastrointest Liver Physiol 2011; 300:G217-27. [PMID: 21109591 PMCID: PMC3043649 DOI: 10.1152/ajpgi.00356.2010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The paradigm for the control of feeding behavior has changed significantly. Research has shown that leptin, in the presence of CCK, may mediate the control of short-term food intake. This interaction between CCK and leptin occurs at the vagus nerve. In the present study, we aimed to characterize the interaction between CCK and leptin in the vagal primary afferent neurons. Single neuronal discharges of vagal primary afferent neurons innervating the gastrointestinal tract were recorded from rat nodose ganglia. Three groups of nodose ganglia neurons were identified: group 1 responded to CCK-8 but not leptin; group 2 responded to leptin but not CCK-8; group 3 responded to high-dose CCK-8 and leptin. In fact, the neurons in group 3 showed CCK-8 and leptin potentiation, and they responded to gastric distention. To identify the CCK-A receptor (CCKAR) affinity states that colocalize with the leptin receptor OB-Rb, we used CCK-JMV-180, a high-affinity CCKAR agonist and low-affinity CCKAR antagonist. As expected, immunohistochemical studies showed that CCK-8 administration significantly potentiated the increase in the number of c-Fos-positive neurons stimulated by leptin in vagal nodose ganglia. Administration of CCK-JMV-180 eliminated the synergistic interaction between CCK-8 and leptin. We conclude that both low- and high-affinity CCKAR are expressed in nodose ganglia. Many nodose neurons bearing low-affinity CCKAR express OB-Rb. These neurons also respond to mechanical distention. An interaction between CCKAR and OB-Rb in these neurons likely facilitates leptin mediation of short-term satiety.
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Affiliation(s)
- Ying Li
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Xiaoyin Wu
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Shiyi Zhou
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Chung Owyang
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
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Sévoz-Couche C, Spyer KM, Jordan D. In vivo modulation of vagal-identified dorsal medullary neurones by activation of different 5-Hydroxytryptamine(2) receptors in rats. Br J Pharmacol 2000; 131:1445-53. [PMID: 11090119 PMCID: PMC1572477 DOI: 10.1038/sj.bjp.0703722] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2000] [Revised: 09/13/2000] [Accepted: 09/19/2000] [Indexed: 11/09/2022] Open
Abstract
1. In in vivo experiments, DOI (a 5-HT(2) receptor agonist), MK-212 (a 5-HT(2C) receptor agonist), and BW-723C86 (a 5-HT(2B) receptor agonist) were applied by ionophoresis to neurones in the rat nucleus tractus solitarius (NTS) receiving vagal afferent input. 2. The majority of the putative 'monosynaptically' vagal activated cells were inhibited by both MK-212 (4/6) and DOI (2/4), but unaffected by BW-723C86 (12/14). In contrast, 'polysynaptically' activated NTS cells were excited by both BW-723C86 (13/19) and DOI (9/10). Inactive 'intermediate' cells were inhibited by BW-723C86 (9/12), MK-212 (5/6) and DOI (3/4), whilst active cells of this group were excited by BW-723C86 (7/13) and DOI (5/5). 3. The selective 5-HT(2B) receptor antagonist LY-202715 significantly reduced the excitatory actions of BW-723C86 on 'intermediate' and 'polysynaptic' cells (13/13), but not the inhibitory effects observed on inactive Group 2 cells (n=5) whereas the selective 5-HT(2C) receptor antagonist RS-102221 reversed the inhibitory effects of MK-212 and DOI on 'monosynaptic and 'intermediate' neurones. 4. Cardio-pulmonary afferent stimulation inhibited two of four putative 'monosynaptically' activated calls and all four inactive intermediate cells. These were also inhibited by DOI and MK-212. In contrast, cardio-pulmonary afferents excited all five active intermediate cells and all six putative 'polysynaptically' activated NTS cells, while all were also previously excited by BW-723C86 and/or DOI. 5. In conclusion, these data demonstrate that neurones in the NTS are affected differently by 5-HT(2) receptor ligands, in regard of their vagal postsynaptic location, the type of cardio-pulmonary afferent they receive and the different 5-HT(2) receptors activated.
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Affiliation(s)
- Caroline Sévoz-Couche
- Department of Physiology, Royal Free and University College Medical School, Royal Free Campus, Rowland Hill Street, London, NW3 2PF
| | - K Michael Spyer
- Department of Physiology, Royal Free and University College Medical School, Royal Free Campus, Rowland Hill Street, London, NW3 2PF
| | - David Jordan
- Department of Physiology, Royal Free and University College Medical School, Royal Free Campus, Rowland Hill Street, London, NW3 2PF
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Page AJ, Blackshaw LA. GABA(B) receptors inhibit mechanosensitivity of primary afferent endings. J Neurosci 1999; 19:8597-602. [PMID: 10493759 PMCID: PMC6783028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/1999] [Revised: 06/06/1999] [Accepted: 06/21/1999] [Indexed: 02/14/2023] Open
Abstract
The modulatory effects of baclofen on the sensitivity of peripheral afferent endings to mechanical stimulation were investigated using an in vitro ferret gastroesophageal vagal afferent preparation. Changes in sensitivity of three types of gastroesophageal vagal afferent endings previously categorized as mucosal, tension, and tension-mucosal (TM) receptors according to their mechanoreceptive field characteristics were investigated. Baclofen (30-200 microM) dose dependently reduced responses of mucosal afferents to mucosal stroking with calibrated von Frey hairs (10-1000 mg). This was reversed by the GABA(B) receptor antagonist SCH50911 (1 microM). TM afferent responses to mucosal stroking (10-1000 mg) were unaffected by baclofen (30-200 microM). However, baclofen (30-200 microM) significantly inhibited the response of 11 of 18 TM afferents to circumferential tension. This was reversed by SCH50911 (1 microM). Baclofen (100 and 200 microM) significantly inhibited the response of all tension receptor afferents to circumferential tension in the lower range (1-3 gm) but not in the higher range (4-7 gm). This inhibition was reversed by SCH50911 (1 microM; n = 3). This study provides the first direct evidence for the inhibitory modulation of peripheral mechanosensory endings by the G-protein-coupled GABA(B) receptor. Inhibition was dose-dependent, pharmacologically reversible, and selective to certain aspects of mechanosensitivity. These findings have important relevance to strategies for selective reduction of sensory input to the CNS at a peripheral site.
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Affiliation(s)
- A J Page
- Nerve-Gut Research Laboratory, Department of Gastrointestinal Medicine, Royal Adelaide Hospital, North Terrace, Adelaide SA 5000, Australia
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