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Sosa MKS, Boorman DC, Keay KA. The impact of sciatic nerve injury and social interactions testing on glucocorticoid receptor expression in catecholaminergic medullary cell populations. Brain Res 2023; 1819:148542. [PMID: 37604315 DOI: 10.1016/j.brainres.2023.148542] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/09/2023] [Accepted: 08/18/2023] [Indexed: 08/23/2023]
Abstract
Paradoxically, while acute pain leads to transiently elevated corticosterone, chronic pain does not result in persistently elevated corticosterone. In the sciatic nerve chronic constriction injury (CCI) model of chronic pain, we have shown that the same nerve injury produces a range of behavioural outcomes, each associated with distinctive adaptations to the HPA-axis to achieve stable plasma corticosterone levels. We also demonstrated that CRF and GR expression in the paraventricular hypothalamus (PVH) was increased in rats that showed persistent changes to their social behaviours during Resident-Intruder testing ('Persistent Effect' rats) when compared to rats that showed no behavioural changes ('No Effect' rats). In this study, we investigated whether these changes were driven in part by altered sensitivity of the brainstem catecholaminergic pathways (known to regulate the PVH) to glucocorticoids. GR expression in adrenergic (C1,C2) and noradrenergic (A1,A2) cells was determined using immunohistochemistry in behaviourally tested CCI rats and in uninjured controls. We found no differences between Persistent Effect and No Effect rats in (1) the glucocorticoid sensitivity of these cells, or (2) the numbers of adrenergic and noradrenergic cells in each region. However, we discovered an overall reduction in GR expression in the non-catecholaminergic cells of these regions in both experimental groups when compared to uninjured controls, most likely attributable to the repeated Resident-Intruder testing. Taken together, these data suggest strongly that brainstem mechanisms are unlikely to play a key role in the rebalancing of the HPA-axis triggered by CCI, increasing the probability that these changes are driven by supra-hypothalamic regions.
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Affiliation(s)
- Maria K S Sosa
- School of Medical Sciences and the Brain and Mind Centre, The University of Sydney, New South Wales 2006, Australia
| | - Damien C Boorman
- School of Medical Sciences and the Brain and Mind Centre, The University of Sydney, New South Wales 2006, Australia
| | - Kevin A Keay
- School of Medical Sciences and the Brain and Mind Centre, The University of Sydney, New South Wales 2006, Australia.
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Chrobok L, Ahern J, Piggins HD. Ticking and talking in the brainstem satiety centre: Circadian timekeeping and interactions in the diet-sensitive clock of the dorsal vagal complex. Front Physiol 2022; 13:931167. [PMID: 36117684 PMCID: PMC9481231 DOI: 10.3389/fphys.2022.931167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
The dorsal vagal complex (DVC) is a key hub for integrating blood-borne, central, and vagal ascending signals that convey important information on metabolic and homeostatic state. Research implicates the DVC in the termination of food intake and the transition to satiety, and consequently it is considered a brainstem satiety centre. In natural and laboratory settings, animals have distinct times of the day or circadian phases at which they prefer to eat, but if and how circadian signals affect DVC activity is not well understood. Here, we evaluate how intrinsic circadian signals regulate molecular and cellular activity in the area postrema (AP), nucleus of the solitary tract (NTS), and dorsal motor nucleus of the vagus (DMV) of the DVC. The hierarchy and potential interactions among these oscillators and their response to changes in diet are considered a simple framework in which to model these oscillators and their interactions is suggested. We propose possible functions of the DVC in the circadian control of feeding behaviour and speculate on future research directions including the translational value of knowledge of intrinsic circadian timekeeping the brainstem.
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Chrobok L, Klich JD, Sanetra AM, Jeczmien-Lazur JS, Pradel K, Palus-Chramiec K, Kepczynski M, Piggins HD, Lewandowski MH. Rhythmic neuronal activities of the rat nucleus of the solitary tract are impaired by high-fat diet - implications for daily control of satiety. J Physiol 2021; 600:751-767. [PMID: 34490628 DOI: 10.1113/jp281838] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Temporal partitioning of daily food intake is crucial for survival and involves the integration of internal circadian states and external influences such as the light-dark cycle and dietary composition. These intrinsic and extrinsic factors are interdependent with misalignment of circadian rhythms promoting body weight gain, while consumption of a calorie-dense diet elevates the risk of obesity and blunts circadian rhythms. Recently, we defined the circadian properties of the dorsal vagal complex of the brainstem, a structure implicated in the control of food intake and autonomic tone, but whether and how 24 h rhythms in this area are influenced by diet remains unresolved. Here we focused on a key structure of this complex, the nucleus of the solitary tract (NTS). We used a combination of immunohistochemical and electrophysiological approaches together with daily monitoring of body weight and food intake to interrogate how the neuronal rhythms of the NTS are affected by a high-fat diet. We report that short-term consumption of a high-fat diet increases food intake during the day and blunts NTS daily rhythms in neuronal discharge. Additionally, we found that a high-fat diet dampens NTS responsiveness to metabolic neuropeptides, and decreases orexin immunoreactive fibres in this structure. These alterations occur without prominent body weight gain, suggesting that a high-fat diet acts initially to reduce activity in the NTS to disinhibit mechanisms that suppress daytime feeding. KEY POINTS: The dorsal vagal complex of the rodent hindbrain possesses intrinsic circadian timekeeping mechanisms In particular, the nucleus of the solitary tract (NTS) is a robust circadian oscillator, independent of the master suprachiasmatic clock Here, we reveal that rat NTS neurons display timed daily rhythms in their neuronal activity and responsiveness to ingestive cues These daily rhythms are blunted or eliminated by a short-term high-fat diet, together with increased consumption of calories during the behaviourally quiescent day Our results help us better understand the circadian control of satiety by the brainstem and its malfunctioning under a high-fat diet.
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Affiliation(s)
- Lukasz Chrobok
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jasmin D Klich
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Anna M Sanetra
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Jagoda S Jeczmien-Lazur
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Kamil Pradel
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Katarzyna Palus-Chramiec
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
| | - Mariusz Kepczynski
- Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University in Krakow, Krakow, Poland
| | - Hugh D Piggins
- School of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Marian H Lewandowski
- Department of Neurophysiology and Chronobiology, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, Krakow, Poland
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Bai Y, Chen YB, Qiu XT, Chen YB, Ma LT, Li YQ, Sun HK, Zhang MM, Zhang T, Chen T, Fan BY, Li H, Li YQ. Nucleus tractus solitarius mediates hyperalgesia induced by chronic pancreatitis in rats. World J Gastroenterol 2019; 25:6077-6093. [PMID: 31686764 PMCID: PMC6824279 DOI: 10.3748/wjg.v25.i40.6077] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/06/2019] [Accepted: 09/10/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Central sensitization plays a pivotal role in the maintenance of chronic pain induced by chronic pancreatitis (CP). We hypothesized that the nucleus tractus solitarius (NTS), a primary central site that integrates pancreatic afferents apart from the thoracic spinal dorsal horn, plays a key role in the pathogenesis of visceral hypersensitivity in a rat model of CP.
AIM To investigate the role of the NTS in the visceral hypersensitivity induced by chronic pancreatitis.
METHODS CP was induced by the intraductal injection of trinitrobenzene sulfonic acid (TNBS) in rats. Pancreatic hyperalgesia was assessed by referred somatic pain via von Frey filament assay. Neural activation of the NTS was indicated by immunohistochemical staining for Fos. Basic synaptic transmission within the NTS was assessed by electrophysiological recordings. Expression of vesicular glutamate transporters (VGluTs), N-methyl-D-aspartate receptor subtype 2B (NR2B), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subtype 1 (GluR1) was analyzed by immunoblotting. Membrane insertion of NR2B and GluR1 was evaluated by electron microscopy. The regulatory role of the NTS in visceral hypersensitivity was detected via pharmacological approach and chemogenetics in CP rats.
RESULTS TNBS treatment significantly increased the number of Fos-expressing neurons within the caudal NTS. The excitatory synaptic transmission was substantially potentiated within the caudal NTS in CP rats (frequency: 5.87 ± 1.12 Hz in CP rats vs 2.55 ± 0.44 Hz in sham rats, P < 0.01; amplitude: 19.60 ± 1.39 pA in CP rats vs 14.71 ± 1.07 pA in sham rats; P < 0.01). CP rats showed upregulated expression of VGluT2, and increased phosphorylation and postsynaptic trafficking of NR2B and GluR1 within the caudal NTS. Blocking excitatory synaptic transmission via the AMPAR antagonist CNQX and the NMDAR antagonist AP-5 microinjection reversed visceral hypersensitivity in CP rats (abdominal withdraw threshold: 7.00 ± 1.02 g in CNQX group, 8.00 ± 0.81 g in AP-5 group and 1.10 ± 0.27 g in saline group, P < 0.001). Inhibiting the excitability of NTS neurons via chemogenetics also significantly attenuated pancreatic hyperalgesia (abdominal withdraw threshold: 13.67 ± 2.55 g in Gi group, 2.00 ± 1.37 g in Gq group, and 2.36 ± 0.67 g in mCherry group, P < 0.01).
CONCLUSION Our findings suggest that enhanced excitatory transmission within the caudal NTS contributes to pancreatic pain and emphasize the NTS as a pivotal hub for the processing of pancreatic afferents, which provide novel insights into the central sensitization of painful CP.
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Affiliation(s)
- Yang Bai
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, Fourth Military Medical University, Xi’an 710032, Shaanxi Province, China
| | - Ying-Biao Chen
- Department of Anatomy, Fujian Health College, Fuzhou 350101, Fujian Province, China
| | - Xin-Tong Qiu
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, Fourth Military Medical University, Xi’an 710032, Shaanxi Province, China
| | - Yan-Bing Chen
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, Fourth Military Medical University, Xi’an 710032, Shaanxi Province, China
| | - Li-Tian Ma
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, Fourth Military Medical University, Xi’an 710032, Shaanxi Province, China
| | - Ying-Qi Li
- Department of Cardiology, The Second Affiliated Hospital of Xian Jiaotong University, Xian Jiaotong University, Xi'an 710004, Shaanxi Province, China
| | - Hong-Ke Sun
- Department of Cardiology, The Second Affiliated Hospital of Xian Jiaotong University, Xian Jiaotong University, Xi'an 710004, Shaanxi Province, China
| | - Ming-Ming Zhang
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, Fourth Military Medical University, Xi’an 710032, Shaanxi Province, China
| | - Ting Zhang
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, Fourth Military Medical University, Xi’an 710032, Shaanxi Province, China
| | - Tao Chen
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, Fourth Military Medical University, Xi’an 710032, Shaanxi Province, China
| | - Bo-Yuan Fan
- Department of Cardiology, The Second Affiliated Hospital of Xian Jiaotong University, Xian Jiaotong University, Xi'an 710004, Shaanxi Province, China
| | - Hui Li
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, Fourth Military Medical University, Xi’an 710032, Shaanxi Province, China
| | - Yun-Qing Li
- Department of Anatomy, Histology and Embryology & K. K. Leung Brain Research Centre, Fourth Military Medical University, Xi’an 710032, Shaanxi Province, China
- Joint Laboratory of Neuroscience at Hainan Medical University and Fourth Military Medical University, Hainan Medical University, Haikou 571199, Hainan Province, China
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Destruction of the Dorsal Motor Nucleus of the Vagus Aggravates Inflammation and Injury from Acid-Induced Acute Esophagitis in a Rat Model. Anal Cell Pathol (Amst) 2019; 2019:8243813. [PMID: 31281769 PMCID: PMC6589286 DOI: 10.1155/2019/8243813] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/10/2019] [Accepted: 05/12/2019] [Indexed: 02/07/2023] Open
Abstract
Background/Aims The aim of this study is to examine the protective effect of the cholinergic anti-inflammatory pathway (CAP) in experimental esophagitis in rats. Methods A total of 40 male Sprague-Dawley (SD) rats were randomly divided into five groups as follows: control group, sham + saline group, sham + acid group, operation + saline group, and operation + acid group. Two weeks after the dorsal motor nucleus of the vagus (DMV) destruction, hydrochloric acid with pepsin was perfused into the lower part of the esophagus for 90 min. The rats were sacrificed 60 min after perfusion. The esophagus was prepared for hematoxylin and eosin (HE) staining, and the degree of inflammation and NF-κB activation in the esophagus was measured. Inflammatory cytokines (TNF-α, IL-6, IL-1β, and PGE2) in the esophagus were measured by ELISA. The brain was removed and processed for c-fos immunohistochemistry staining. The c-fos-positive neurons were counted and analyzed. Results The TNF-α, IL-1β, IL-6, and PGE2 concentrations in the esophageal tissue increased after acid perfusion. The microscopic esophagitis scores and the activation of NF-κB p65 in the esophagus were significantly higher in the operation + acid group than in the operation + saline group. c-fos-positive neurons significantly increased in rats receiving acid perfusion in the amygdala (AM), the paraventricular nucleus of the hypothalamus (PVN), the parabrachial nucleus (PBN), the nucleus of the solitary tract (NTS)/DMV, the nucleus ambiguous (NA), the reticular nucleus of the medulla (RNM), and the area postrema (AP). After DMV destruction, c-fos expression was reduced in the AM, PVN, PBN, NTS/DMV, NA, RNM, and AP, especially in the AM, PVN, NTS/DMV, RNM, and AP. Conclusions The DMV is an important nucleus of the CAP. The DMV lesion can aggravate esophageal inflammation and injury from acid-induced acute esophagitis in a rat model. The CAP has a protective effect on the acute esophagitis rat model and could be a new therapy for reflux esophagitis (RE).
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Zafra MA, Agüera AD, Molina F, Puerto A. Relevance of the nucleus of the solitary tract, gelatinous part, in learned preferences induced by intragastric nutrient administration. Appetite 2017; 118:90-96. [PMID: 28789870 DOI: 10.1016/j.appet.2017.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Revised: 08/02/2017] [Accepted: 08/03/2017] [Indexed: 12/18/2022]
Abstract
Food preferences have been investigated in Wistar rats utilizing a learned concurrent flavor preference behavioral procedure. Previous studies have demonstrated that the perivagal administration of neurotoxin capsaicin disrupts the learning of preferences induced by intragastric administration of rewarding nutrients (pre-digested milk). The vagus nerve projects almost exclusively towards the nucleus of the solitary tract (NST), a brain medullary gateway for visceral signals. The objective of this study was to investigate the participation of the lateral portion of the dorsomedial region, the gelatinous subnucleus (SolG), in the learning of a concurrent preference task. Results show that unlike neurologically intact animals, which learn this task correctly, animals lesioned in the gelatinous part of NST manifest a disruption of discrimination learning. Thus, intakes of the flavored stimulus paired with predigested liquid diet and of the flavored stimulus paired with physiological saline were virtually identical. However, SolG- and sham-lesioned groups consumed similar total amounts of both flavors. These findings suggest that SolG, as a relay of the vagus nerve, along with its anatomical projection, the external lateral parabrachial subnucleus (LPBe), may constitute an anatomical axis that is important in the induction of concurrent flavor/side preferences. It also appears to be relevant in other behavioral processes that require rapid processing of information from the upper gastrointestinal tract.
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Affiliation(s)
- María A Zafra
- Department of Psychobiology, University of Granada, Campus de Cartuja, Granada 18071, Spain; Mind, Brain, and Behavior Research Center (CIMCYC), University of Granada, Campus de Cartuja, Granada 18071, Spain.
| | - Antonio D Agüera
- Department of Psychobiology, University of Granada, Campus de Cartuja, Granada 18071, Spain
| | - Filomena Molina
- Department of Psychobiology, University of Granada, Campus de Cartuja, Granada 18071, Spain; Mind, Brain, and Behavior Research Center (CIMCYC), University of Granada, Campus de Cartuja, Granada 18071, Spain
| | - Amadeo Puerto
- Department of Psychobiology, University of Granada, Campus de Cartuja, Granada 18071, Spain; Mind, Brain, and Behavior Research Center (CIMCYC), University of Granada, Campus de Cartuja, Granada 18071, Spain
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Sabbatini M, Grossini E, Molinari C, Mary DASG, Vacca G, Cannas M. Gastric distension causes changes in heart rate and arterial blood pressure by affecting the crosstalk between vagal and splanchnic systems in anesthetised rats. Exp Brain Res 2017; 235:1081-1095. [PMID: 28091707 DOI: 10.1007/s00221-016-4819-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 11/01/2016] [Indexed: 12/31/2022]
Abstract
Various hindbrain nuclei have been demonstrated to be involved in the control of the cardiovascular reflexes elicited by both non-noxious and noxious gastric distension, through parasympathetic and sympathetic activation. The different role played by the branches of autonomic nervous system in exerting these effects and their crosstalk in relation to low-/high-pressure distension rate has not been examined yet. Therefore, in the present work, monolateral and bilateral vagotomy and splanchnicotomy were performed in anesthetised rats to analyse the involvement of hindbrain nuclei in haemodynamic changes caused by gastric distension at high (80 mmHg) and low (15 mmHg) pressure. The analysis of c-Fos expression in neuronal areas involved in cardiovascular control allowed us to examine their recruitment in response to various patterns of gastric distension and the crosstalk between vagal and splanchnic systems. The results obtained show that the low-pressure (non-noxious) gastric distension increases both heart rate and arterial blood pressure. In addition, the vagus nerve and hindbrain nuclei, such as nucleus ambiguous, ventrolateral medulla and lateral reticular nucleus, appear to be primarily involved in observed responses. In particular, we have found that although vagus nerve plays a central role in exerting those cardiovascular reflex changes at low gastric distension, for its functional expression an intact splanchnic system is mandatory. Hence, the absence of splanchnic input attenuates pressor responses or turns them into depressor responses. Instead at high-pressure (noxious) gastric distension, the splanchnic nerve represents the primary component in regulating the reflex cardiovascular effects.
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Affiliation(s)
- Maurizio Sabbatini
- Department of Science and Technology Innovation, University of Eastern Piedmont, UPO, T. Michel, 11, Alessandria, 15121, Italia.
| | - Elena Grossini
- Department of Translational Medicine, University of Eastern Piedmont, UPO, Novara, Italia
| | - Claudio Molinari
- Department of Translational Medicine, University of Eastern Piedmont, UPO, Novara, Italia
| | - David A S G Mary
- Department of Translational Medicine, University of Eastern Piedmont, UPO, Novara, Italia
| | - Giovanni Vacca
- Department of Translational Medicine, University of Eastern Piedmont, UPO, Novara, Italia
| | - Mario Cannas
- Department of Health Sciences, University of Eastern Piedmont, UPO, Novara, Italia
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Abstract
The neural control of appetite is important for understanding motivated behavior as well as the present rising prevalence of obesity. Over the past several years, new tools for cell type-specific neuron activity monitoring and perturbation have enabled increasingly detailed analyses of the mechanisms underlying appetite-control systems. Three major neural circuits strongly and acutely influence appetite but with notably different characteristics. Although these circuits interact, they have distinct properties and thus appear to contribute to separate but interlinked processes influencing appetite, thereby forming three pillars of appetite control. Here, we summarize some of the key characteristics of appetite circuits that are emerging from recent work and synthesize the findings into a provisional framework that can guide future studies.
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Affiliation(s)
- Scott M Sternson
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147;
| | - Anne-Kathrin Eiselt
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147;
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9
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Zséli G, Vida B, Martinez A, Lechan RM, Khan AM, Fekete C. Elucidation of the anatomy of a satiety network: Focus on connectivity of the parabrachial nucleus in the adult rat. J Comp Neurol 2016; 524:2803-27. [PMID: 26918800 DOI: 10.1002/cne.23992] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 10/09/2015] [Accepted: 02/22/2016] [Indexed: 01/01/2023]
Abstract
We hypothesized that brain regions showing neuronal activation after refeeding comprise major nodes in a satiety network, and tested this hypothesis with two sets of experiments. Detailed c-Fos mapping comparing fasted and refed rats was performed to identify candidate nodes of the satiety network. In addition to well-known feeding-related brain regions such as the arcuate, dorsomedial, and paraventricular hypothalamic nuclei, lateral hypothalamic area, parabrachial nucleus (PB), nucleus of the solitary tract and central amygdalar nucleus, other refeeding activated regions were also identified, such as the parastrial and parasubthalamic nuclei. To begin to understand the connectivity of the satiety network, the interconnectivity of PB with other refeeding-activated neuronal groups was studied following administration of anterograde or retrograde tracers into the PB. After allowing for tracer transport time, the animals were fasted and then refed before sacrifice. Refeeding-activated neurons that project to the PB were found in the agranular insular area; bed nuclei of terminal stria; anterior hypothalamic area; arcuate, paraventricular, and dorsomedial hypothalamic nuclei; lateral hypothalamic area; parasubthalamic nucleus; central amygdalar nucleus; area postrema; and nucleus of the solitary tract. Axons originating from the PB were observed to closely associate with refeeding-activated neurons in the agranular insular area; bed nuclei of terminal stria; anterior hypothalamus; paraventricular, arcuate, and dorsomedial hypothalamic nuclei; lateral hypothalamic area; central amygdalar nucleus; parasubthalamic nucleus; ventral posterior thalamic nucleus; area postrema; and nucleus of the solitary tract. These data indicate that the PB has bidirectional connections with most refeeding-activated neuronal groups, suggesting that short-loop feedback circuits exist in this satiety network. J. Comp. Neurol. 524:2803-2827, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Györgyi Zséli
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary, 1083.,Neuroendocrinology Program, Semmelweis University Neurosciences Doctoral School, Budapest, Hungary, 1085
| | - Barbara Vida
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary, 1083.,Department of Neuroscience, Faculty of Information Technology, Pázmány Péter Catholic University, Budapest, Hungary, 1088
| | - Anais Martinez
- UTEP Systems Neuroscience Laboratory, Department of Biological Sciences and Border Biomedical Research Center, University of Texas at El Paso, El Paso, Texas, 79902.,Graduate Program in Pathobiology, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, 79902
| | - Ronald M Lechan
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts, 02111.,Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, 02111
| | - Arshad M Khan
- UTEP Systems Neuroscience Laboratory, Department of Biological Sciences and Border Biomedical Research Center, University of Texas at El Paso, El Paso, Texas, 79902
| | - Csaba Fekete
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary, 1083.,Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Tupper Research Institute, Tufts Medical Center, Boston, Massachusetts, 02111
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Browning KN, Travagli RA. Central nervous system control of gastrointestinal motility and secretion and modulation of gastrointestinal functions. Compr Physiol 2015; 4:1339-68. [PMID: 25428846 DOI: 10.1002/cphy.c130055] [Citation(s) in RCA: 320] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Although the gastrointestinal (GI) tract possesses intrinsic neural plexuses that allow a significant degree of autonomy over GI functions, the central nervous system (CNS) provides extrinsic neural inputs that regulate, modulate, and control these functions. While the intestines are capable of functioning in the absence of extrinsic inputs, the stomach and esophagus are much more dependent upon extrinsic neural inputs, particularly from parasympathetic and sympathetic pathways. The sympathetic nervous system exerts a predominantly inhibitory effect upon GI muscle and provides a tonic inhibitory influence over mucosal secretion while, at the same time, regulates GI blood flow via neurally mediated vasoconstriction. The parasympathetic nervous system, in contrast, exerts both excitatory and inhibitory control over gastric and intestinal tone and motility. Although GI functions are controlled by the autonomic nervous system and occur, by and large, independently of conscious perception, it is clear that the higher CNS centers influence homeostatic control as well as cognitive and behavioral functions. This review will describe the basic neural circuitry of extrinsic inputs to the GI tract as well as the major CNS nuclei that innervate and modulate the activity of these pathways. The role of CNS-centered reflexes in the regulation of GI functions will be discussed as will modulation of these reflexes under both physiological and pathophysiological conditions. Finally, future directions within the field will be discussed in terms of important questions that remain to be resolved and advances in technology that may help provide these answers.
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Affiliation(s)
- Kirsteen N Browning
- Department of Neural and Behavioral Sciences, Penn State College of Medicine, Hershey, Pennsylvania
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Strong Manual Acupuncture Manipulation Could Better Inhibit Spike Frequency of the Dorsal Horn Neurons in Rats with Acute Visceral Nociception. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:675437. [PMID: 26257816 PMCID: PMC4518182 DOI: 10.1155/2015/675437] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Revised: 04/21/2015] [Accepted: 04/21/2015] [Indexed: 12/12/2022]
Abstract
Afferent impulses from visceral nociception can be regulated by acupuncture at spinal cord level; however, the effects of different manual acupuncture (MA) manipulations on the afferent impulses are still unknown. Here, we analyzed the spike frequency of excitatory gastric-related wide dynamic range (WDR) neurons in spinal dorsal horn (SDH) following acute gastric distension (GD) in rats and compared their responses to MA manipulations with four different frequencies (0.5, 1, 2, and 3 Hz) at Zusanli (ST36). Results indicated that the spike frequency was increased by acute GD stimulation. Under acute GD circumstances, the spike frequency was further activated by weak MA stimulation (0.5 and 1 Hz), while being significantly inhibited by strong MA stimulation (2 and 3 Hz). After 10 minutes of the strong MA stimulation, same intensity of acute GD caused less spike frequency. Our previous researches had demonstrated that different MA manipulations could increase spike frequency in an intensity-dependent manner in normal rats; these findings suggest that acupuncture may have different modulatory effects depending on the state of the stomach. Since neuronal spike frequency was related to the level of nociception, the results suggest that strong MA manipulation may have better effect on acute visceral nociception.
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Panneton WM, Gan Q, Ariel M. Injections of Algesic Solutions into Muscle Activate the Lateral Reticular Formation: A Nociceptive Relay of the Spinoreticulothalamic Tract. PLoS One 2015; 10:e0130939. [PMID: 26154308 PMCID: PMC4496070 DOI: 10.1371/journal.pone.0130939] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 05/26/2015] [Indexed: 02/07/2023] Open
Abstract
Although musculoskeletal pain disorders are common clinically, the central processing of muscle pain is little understood. The present study reports on central neurons activated by injections of algesic solutions into the gastrocnemius muscle of the rat, and their subsequent localization by c-Fos immunohistochemistry in the spinal cord and brainstem. An injection (300μl) of an algesic solution (6% hypertonic saline, pH 4.0 acetate buffer, or 0.05% capsaicin) was made into the gastrocnemius muscle and the distribution of immunolabeled neurons compared to that obtained after control injections of phosphate buffered saline [pH 7.0]. Most labeled neurons in the spinal cord were found in laminae IV-V, VI, VII and X, comparing favorably with other studies, with fewer labeled neurons in laminae I and II. This finding is consistent with the diffuse pain perception due to noxious stimuli to muscles mediated by sensory fibers to deep spinal neurons as compared to more restricted pain localization during noxious stimuli to skin mediated by sensory fibers to superficial laminae. Numerous neurons were immunolabeled in the brainstem, predominantly in the lateral reticular formation (LRF). Labeled neurons were found bilaterally in the caudalmost ventrolateral medulla, where neurons responsive to noxious stimulation of cutaneous and visceral structures lie. Immunolabeled neurons in the LRF continued rostrally and dorsally along the intermediate reticular nucleus in the medulla, including the subnucleus reticularis dorsalis caudally and the parvicellular reticular nucleus more rostrally, and through the pons medial and lateral to the motor trigeminal nucleus, including the subcoerulear network. Immunolabeled neurons, many of them catecholaminergic, were found bilaterally in the nucleus tractus solitarii, the gracile nucleus, the A1 area, the CVLM and RVLM, the superior salivatory nucleus, the nucleus locus coeruleus, the A5 area, and the nucleus raphe magnus in the pons. The external lateral and superior lateral subnuclei of the parabrachial nuclear complex were consistently labeled in experimental data, but they also were labeled in many control cases. The internal lateral subnucleus of the parabrachial complex was labeled moderately. Few immunolabeled neurons were found in the medial reticular formation, however, but the rostroventromedial medulla was labeled consistently. These data are discussed in terms of an interoceptive, multisynaptic spinoreticulothalamic path, with its large receptive fields and role in the motivational-affective components of pain perceptions.
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Affiliation(s)
- W. Michael Panneton
- Department of Pharmacological and Physiological Science, Saint Louis University, St. Louis, MO, United States of America
- * E-mail:
| | - Qi Gan
- Department of Pharmacological and Physiological Science, Saint Louis University, St. Louis, MO, United States of America
| | - Michael Ariel
- Department of Pharmacological and Physiological Science, Saint Louis University, St. Louis, MO, United States of America
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Martins I, de Vries M, Teixeira-Pinto A, Fadel J, Wilson S, Westerink B, Tavares I. Noradrenaline increases pain facilitation from the brain during inflammatory pain. Neuropharmacology 2013; 71:299-307. [DOI: 10.1016/j.neuropharm.2013.04.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 02/18/2013] [Accepted: 04/04/2013] [Indexed: 01/08/2023]
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14
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Min DK, Tuor UI, Chelikani PK. Gastric distention induced functional magnetic resonance signal changes in the rodent brain. Neuroscience 2011; 179:151-8. [PMID: 21284950 DOI: 10.1016/j.neuroscience.2011.01.051] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 01/14/2011] [Accepted: 01/23/2011] [Indexed: 12/29/2022]
Abstract
Investigating the localization of gastric sensation within the brain is important for understanding the neural correlates of satiety. Previous rodent studies have identified the brain-stem and hypothalamus as key mediators of gastric distention-induced satiation. Although, recent blood oxygen level-dependent functional magnetic resonance imaging (BOLD fMRI) studies in humans have identified a role for higher cortico-limbic structures in mediating the satiation effects of gastric distention, the role of these regions in rodents remains to be characterized. We determined the effects of gastric distention on global spatio-temporal BOLD fMRI signal changes in the rodent brain. Brain images were acquired with a high resolution 9.4 T magnet during gastric distention with continuous monitoring of blood pressure in adult male Sprague Dawley rats (n=8-10). Distention of the stomach with an intragastric balloon, at rates which mimicked the rate of consumption and emptying of a mixed nutrient liquid meal, resulted in robust reduction in food intake and increase in blood pressure. Gastric distention increased BOLD fMRI activity within homeostatic regions such as the hypothalamus and nucleus tractus solitarius, as well as non homeostatic regions including the hippocampus, amygdala, thalamus, cerebellum and the cortex (cingulate, insular, motor and sensory cortices). Further, the increase in BOLD fMRI activity following distention was strongly correlated to an increase in blood pressure. These results indicate that gastric distention, mimicking the rate of intake and emptying of a liquid meal, increases BOLD fMRI activity in both homeostatic and non homeostatic brain circuits which regulate food intake, and that these BOLD fMRI signal changes may in part be attributable to transient increases in blood pressure.
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Affiliation(s)
- D K Min
- Gastrointestinal Research Group, Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
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15
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Godino A, Margatho LO, Caeiro XE, Antunes-Rodrigues J, Vivas L. Activation of lateral parabrachial afferent pathways and endocrine responses during sodium appetite regulation. Exp Neurol 2010; 221:275-84. [DOI: 10.1016/j.expneurol.2009.11.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 10/05/2009] [Accepted: 11/03/2009] [Indexed: 11/29/2022]
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16
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Bercik P, Verdú EF, Foster JA, Lu J, Scharringa A, Kean I, Wang L, Blennerhassett P, Collins SM. Role of gut-brain axis in persistent abnormal feeding behavior in mice following eradication of Helicobacter pylori infection. Am J Physiol Regul Integr Comp Physiol 2009; 296:R587-94. [PMID: 19129375 DOI: 10.1152/ajpregu.90752.2008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Bacterial infection can trigger the development of functional GI disease. Here, we investigate the role of the gut-brain axis in gastric dysfunction during and after chronic H. pylori infection. Control and chronically H. pylori-infected Balb/c mice were studied before and 2 mo after bacterial eradication. Gastric motility and emptying were investigated using videofluoroscopy image analysis. Gastric mechanical viscerosensitivity was assessed by cardioautonomic responses to distension. Feeding patterns were recorded by a computer-assisted system. Plasma leptin, ghrelin, and CCK levels were measured using ELISA. IL-1beta, TNF-alpha, proopiomelanocortin (POMC), and neuropeptide Y mRNAs were assessed by in situ hybridizations on frozen brain sections. Gastric inflammation was assessed by histology and immunohistochemistry. As shown previously, H. pylori-infected mice ate more frequently than controls but consumed less food per bout, maintaining normal body weight. Abnormal feeding behavior was accompanied by elevated plasma ghrelin and postprandial CCK, higher TNF-alpha (median eminence), and lower POMC (arcuate nucleus) mRNA. Infected mice displayed delayed gastric emptying and visceral hypersensitivity. Eradication therapy normalized gastric emptying and improved gastric sensitivity but had no effect on eating behavior. This was accompanied by persistently increased TNF-alpha in the brain and gastric CD3(+) T-cell counts. In conclusion, chronic H. pylori infection in mice alters gastric emptying and mechanosensitivity, which improve after bacterial eradication. A feeding pattern reminiscent of early satiety persists after H. pylori eradication and is accompanied by increased TNF-alpha in the brain. The results support a role for altered gut-brain pathways in the maintenance of postinfective gut dysfunction.
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Affiliation(s)
- Premysl Bercik
- Intestinal Diseases Research Program, McMaster Univ., MUMC 4W8, Hamilton, Ontario L8N 3Z5.
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17
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Morales T, Aguilar L, Ramos E, Mena F, Morgan C. Fos expression induced by milk ingestion in the caudal brainstem of neonatal rats. Brain Res 2008; 1241:76-83. [DOI: 10.1016/j.brainres.2008.09.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 09/02/2008] [Accepted: 09/03/2008] [Indexed: 12/14/2022]
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18
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Sabbatini M, Molinari C, Grossini E, Piffanelli V, Mary DASG, Vacca G, Cannas M. GABAA receptors expression pattern in rat brain following low pressure distension of the stomach. Neuroscience 2008; 152:449-58. [PMID: 18280049 DOI: 10.1016/j.neuroscience.2008.01.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 12/17/2007] [Accepted: 01/10/2008] [Indexed: 11/19/2022]
Abstract
It is known that gastric mechanoreceptor stimuli are widely integrated into neuronal circuits that involve visceral nuclei of hindbrain as well as several central brain areas. GABAergic neurons are widely represented in hindbrain nuclei controlling gastric motor functions, but limited information is available specifically about GABA(A)-responding neurons in brain visceral areas. The present investigation was designed to determine the central sensory neuronal pathways and their GABA(A)-alpha1 and -alpha3 receptor presenting neurons that respond to gastric mechanoreceptor stimulation within the entire rat brain. Low pressure gastric distension was used to deliver physiological mechanical stimuli in anesthetized rats, and different protocols of gastric distension were performed to mimic different stimulation patterns with and without sectioning vagal and/or splanchnic afferent nerves. Mapping of activated neurons was investigated using double colorimetric immunohistochemistry for GABA(A)-alpha1 or -alpha3 subunits and c-Fos. Following stomach distension, neurons expressing GABA(A) receptors with alpha1 or alpha3 subunits were detected. Low frequency gastric distension induced c-Fos expression in nucleus tractus solitarii (NTS) only, whereas in the high frequency gastric distension c-Fos positive nuclei were found in lateral reticular nucleus and in NTS in addition to some forebrain areas. In contrast, during the tonic-rapid gastric distension the neuronal activation was found in hindbrain, midbrain and forebrain areas. Moreover different protocols of gastric stimulation activated diverse patterns of neurons presenting GABA(A)-alpha1 or -alpha3 receptors within responding brain nuclei, which may indicate a probable functional significance of differential expression of GABA(A)-responding neurons. The same protocol of gastric distension performed in vagotomized rats has confirmed the primary role of the vagus in the response of activation of gastric brain areas, whereas neuronal input of splanchnic origins was shown to play an important role in modulating the mechanogastric response of brain areas.
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Affiliation(s)
- M Sabbatini
- Laboratorio di Anatomia Umana, Dipartimento Medicina Clinica e Sperimentale, Università del Piemonte Orientale, Novara, Italy.
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19
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Ruud J, Blomqvist A. Identification of rat brainstem neuronal structures activated during cancer-induced anorexia. J Comp Neurol 2007; 504:275-86. [PMID: 17640050 DOI: 10.1002/cne.21407] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In cancer-related anorexia, body weight loss is paradoxically associated with reduced appetite, which is contrary to the situation during starvation, implying that the normal coupling of food intake to energy expenditure is disarranged. Here we examined brainstem mechanisms that may underlie suppression of food intake in a rat model of cancer anorexia. Cultured Morris 7777 hepatoma cells were injected subcutaneously in Buffalo rats, resulting in slowly growing tumor and reduced food intake and body weight loss after about 10 days. The brainstem was examined for induced expression of the transcription factors Fos and FosB as signs of neuronal activation. The results showed that anorexia and retarded body weight growth were associated with Fos protein expression in the area postrema, the general visceral region of the nucleus of the solitary tract, and the external lateral parabrachial nucleus, structures that also display Fos after peripheral administration of satiating or anorexigenic stimuli. The magnitude of the Fos expression was specifically related to the size of induced tumor, and not associated with weight loss per se, because it was not present in pair-fed or food-deprived rats. It also appeared to be independent of proinflammatory cytokines, as determined by the absence of increased cytokine levels in plasma and induced cytokine and cyclooxygenase expression in the brain. The findings thus provide evidence that cancer-associated anorexia and weight loss in this model is associated with activation of brainstem circuits involved in the suppression of food intake, and suggest that this occurs by inflammatory-independent mechanisms.
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Affiliation(s)
- Johan Ruud
- Division of Cell Biology, Department of Biomedicine and Surgery, Faculty of Health Sciences, Linköping University, Linköping, Sweden
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20
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Godino A, De Luca LA, Antunes-Rodrigues J, Vivas L. Oxytocinergic and serotonergic systems involvement in sodium intake regulation: satiety or hypertonicity markers? Am J Physiol Regul Integr Comp Physiol 2007; 293:R1027-36. [PMID: 17567719 DOI: 10.1152/ajpregu.00078.2007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies demonstrated the inhibitory participation of serotonergic (5-HT) and oxytocinergic (OT) neurons on sodium appetite induced by peritoneal dialysis (PD) in rats. The activity of 5-HT neurons increases after PD-induced 2% NaCl intake and decreases after sodium depletion; however, the activity of the OT neurons appears only after PD-induced 2% NaCl intake. To discriminate whether the differential activations of the 5-HT and OT neurons in this model are a consequence of the sodium satiation process or are the result of stimulation caused by the entry to the body of a hypertonic sodium solution during sodium access, we analyzed the number of Fos-5-HT- and Fos-OT-immunoreactive neurons in the dorsal raphe nucleus and the paraventricular nucleus of the hypothalamus-supraoptic nucleus, respectively, after isotonic vs. hypertonic NaCl intake induced by PD. We also studied the OT plasma levels after PD-induced isotonic or hypertonic NaCl intake. Sodium intake induced by PD significantly increased the number of Fos-5-HT cells, independently of the concentration of NaCl consumed. In contrast, the number of Fos-OT neurons increased after hypertonic NaCl intake, in both depleted and nondepleted animals. The OT plasma levels significantly increased only in the PD-induced 2% NaCl intake group in relation to others, showing a synergic effect of both factors. In summary, 5-HT neurons were activated after body sodium status was reestablished, suggesting that this system is activated under conditions of satiety. In terms of the OT system, both OT neural activity and OT plasma levels were increased by the entry of hypertonic NaCl solution during sodium consumption, suggesting that this system is involved in the processing of hyperosmotic signals.
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Affiliation(s)
- Andrea Godino
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, Casilla de Correo 389, 5000-Córdoba, Argentina
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21
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De Jonghe BC, Hajnal A, Covasa M. Decreased gastric mechanodetection, but preserved gastric emptying, in CCK-1 receptor-deficient OLETF rats. Am J Physiol Gastrointest Liver Physiol 2006; 291:G640-9. [PMID: 16728725 PMCID: PMC3607512 DOI: 10.1152/ajpgi.00109.2006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Obese CCK-1 receptor-lacking Otsuka Long Evans Tokushima fatty (OLETF) rats are hyperphagic relative to control, nonmutant Long Evans Tokushima Otsuka (LETO) rats. This study sought to assess whether the overeating observed in OLETF rats is associated with changes in gastric emptying rates or detection of gastric volume. We performed experiments in both 12- and 29-wk-old OLETF and LETO rats to address possible alterations in gastric functions during the development of increased body weight and blood glucose abnormalities in OLETF rats. Gastric emptying of a 5-g solid chow test meal was not significantly different between strains at either 1, 2, or 4 h postmeal. When rats with ad libitum access to chow were tested, there were no significant differences in gastric emptying between strains at any time period despite OLETF rats consuming significantly more chow than LETO rats. Similar to solid food, 5-min gastric emptying of a 5-ml isosmotic and hyperosmotic saline or glucose load was not significantly different between strains. When the stomach was distended with a 15-ml semisolid chow load, there was no significance difference in emptying at either 1 or 2 h. No significant differences in gastric emptying were detected between 12- and 29-wk-old rats under any conditions. Both young and old OLETF rats, however, reduced sham intake significantly less compared with LETO rats during a brief period of gastric distension by 5- or 10-ml balloon inflation. Finally, OLETF rats showed decreased Fos expression in the nucleus of the solitary tract relative to LETO rats after an 8-ml gastric distension. These findings demonstrate that OLETF rats do not express deficits in controlling gastric emptying rates; however, they exhibit decreased behavioral and vagal responsiveness to gastric distension that may contribute to the increased meal size in these animals.
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Affiliation(s)
- Bart C. De Jonghe
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA 16802
| | - Andras Hajnal
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, College of Medicine, Hershey, PA 17033
| | - Mihai Covasa
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA 16802
- Address correspondence to: Department of Nutritional Sciences College of Health and Human Development The Pennsylvania State University 126 South Henderson University Park, PA, 16802 Telephone: 814-863-2919 Fax: 814-863-6103
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22
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Hayes MR, Covasa M. Gastric distension enhances CCK-induced Fos-like immunoreactivity in the dorsal hindbrain by activating 5-HT3 receptors. Brain Res 2006; 1088:120-30. [PMID: 16630589 DOI: 10.1016/j.brainres.2006.03.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Revised: 03/06/2006] [Accepted: 03/07/2006] [Indexed: 10/24/2022]
Abstract
The combination of gastric distension and cholecystokinin (CCK) enhances both suppression of food intake and induction of c-Fos-like immunoreactivity (Fos-LI) in the dorsal vagal complex (DVC). Previously, we have shown that serotonin type-3 (5-HT3) receptor mediation of suppression of food intake by CCK requires gastric participation. Therefore, we hypothesized that 5-HT3 receptors mediate CCK-induced Fos-LI in the dorsal hindbrain through a mechanism that involves gastric distension. To test this hypothesis, we counted Fos-LI in the DVC of ondansetron (1 mg/kg; 5-HT3 receptor antagonist) and vehicle-treated rats following gastric balloon distension (5 ml), CCK (1 microg/kg) administration, or CCK combined with gastric distension. Ondansetron administration attenuated DVC Fos-LI by CCK administration. Likewise, ondansetron attenuated Fos-LI by gastric distension in the DVC, specifically within the nucleus of the solitary tract (NTS) and area postrema (AP) nuclei. The most pronounced attenuation of distension-induced Fos-LI by ondansetron occurred in the NTS, particularly in the medial and intermedial NTS. When combined, CCK and gastric distension enhanced Fos-LI in the DVC greater than each treatment alone. Furthermore, ondansetron administration attenuated the overall DVC enhanced Fos-LI induced by CCK + gastric distension, in particular at the NTS and AP nuclei. We found that, within the mid-to-caudal regions of the NTS and AP, 5-HT3 receptors most significantly mediate neuronal activation by CCK + distension. In conjunction with previous behavioral data, these results show that gastric distension enhances CCK-induced neuronal activation in the DVC by activating 5-HT3 receptors.
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Affiliation(s)
- Matthew R Hayes
- Department of Nutritional Sciences, College of Health and Human Development, The Pennsylvania State University, 126 South Henderson, University Park, PA 16802-6504, USA.
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Martínez V, Wang L, Taché Y. Proximal colon distension induces Fos expression in the brain and inhibits gastric emptying through capsaicin-sensitive pathways in conscious rats. Brain Res 2006; 1086:168-80. [PMID: 16626641 DOI: 10.1016/j.brainres.2006.02.063] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Revised: 02/15/2006] [Accepted: 02/19/2006] [Indexed: 01/26/2023]
Abstract
We assessed brain nuclei activated during noxious mechanical distension of the proximal colon in conscious rats, using Fos as a marker of neuronal activation, and functional reflex changes in gastric emptying associated to colon distension. The role of capsaicin-sensitive afferents in Fos and gastric responses to distension was also investigated. Compared with sham distension, isovolumetric phasic distension of the proximal colon (10 ml, 30 s on/off for 10 min) increased significantly Fos expression 1 h after distension in selective brain areas, most prominently, the paraventricular and supraoptic nuclei of the hypothalamus (13-fold and 80-fold, respectively), the locus coeruleus-Barrington's nucleus complex (2-fold), area postrema (7-fold) and the nucleus tractus solitarius (4-fold). Increased Fos expression was also observed in the cingulate cortex, posterior paraventricular nucleus of the thalamus, periaqueductal gray and ventrolateral medulla. Distension of the proximal colon significantly inhibited gastric emptying by 82% and 34%, as measured 30 and 60 min after the distension respectively, compared with control. Pretreatment with systemic capsaicin prevented both the brain increase in Fos expression and the inhibition of gastric emptying induced by the colon distension. These results show that visceral pain arising from the proximal colon activates a complex neuronal network that includes specific brain nuclei involved in the integration of autonomic, neuroendocrine and behavioral responses to pain and an inhibitory motor reflex in other gut areas (delayed gastric emptying). Capsaicin-sensitive afferent pathways are involved in mediating brain neuronal activation and functional changes associated with noxious visceral stimulation.
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Affiliation(s)
- Vicente Martínez
- CURE: Digestive Diseases Research Center, Division of Digestive Diseases, David Geffen School of Medicine, University of California at Los Angeles, and VA Greater Los Angeles Healthcare System, 90073, USA
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Molinari C, Sabbatini M, Grossini E, Mary DASG, Cannas M, Vacca G. Cardiovascular effects and c-Fos expression in the rat hindbrain in response to innocuous stomach distension. Brain Res Bull 2006; 69:140-6. [PMID: 16533662 DOI: 10.1016/j.brainresbull.2005.11.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2005] [Revised: 11/21/2005] [Accepted: 11/23/2005] [Indexed: 02/05/2023]
Abstract
The present work was planned to study the effects of non-noxious gastric distension on hemodynamic variables and on cardiovascular hindbrain areas detected by means of c-Fos immunoreactivity, to determine the afferent and central mechanisms involved. In anesthetized rats, innocuous stomach distension increased arterial blood pressure and heart rate and induced c-Fos immunoreactivity within nucleus tractus solitarii, nucleus ambiguus, ventrolateral medulla and lateral reticular nucleus. Bilateral vagotomy abolished the pressor response and c-Fos immunoreactivity in nucleus ambiguus and ventrolateral medulla. Also, c-Fos immunoreactivity was significantly decreased in nucleus tractus solitarii and lateral reticular nucleus. After bilateral splanchnicotomy the pressor and tachycardic responses caused by gastric distension were reduced. c-Fos immunoreactivity in nucleus tractus solitarii, lateral reticular nucleus and nucleus ambiguus was reduced in comparison to the intact rats. In ventrolateral medulla a preferential localization of c-Fos immunoreactivity was found within its caudal portion. It was shown that such gastric distension, known to activate low threshold mechanoreceptors, induced cardiovascular effects via both vagal and splanchnic afferents and involving their central convergence and interaction in modulating the baroreceptor buffer system.
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van de Wall EHEM, Duffy P, Ritter RC. CCK enhances response to gastric distension by acting on capsaicin-insensitive vagal afferents. Am J Physiol Regul Integr Comp Physiol 2005; 289:R695-703. [PMID: 15905220 DOI: 10.1152/ajpregu.00809.2004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Capsaicin treatment destroys vagal afferent C fibers and markedly attenuates reduction of food intake and induction of hindbrain Fos expression by CCK. However, both anatomical and electrophysiological data indicate that some gastric vagal afferents are not destroyed by capsaicin. Because CCK enhances behavioral and electrophysiological responses to gastric distension in rats and people, we hypothesized that CCK might enhance the vagal afferent response to gastric distension via an action on capsaicin-insensitive vagal afferents. To test this hypothesis, we quantified expression of Fos-like immunoreactivity (Fos) in the dorsal vagal complex (DVC) of capsaicin-treated (Cap) and control rats (Veh), following gastric balloon distension alone and in combination with CCK injection. In Veh rats, intraperitoneal CCK significantly increased DVC Fos, especially in nucleus of the solitary tract (NTS), whereas in Cap rats, CCK did not significantly increase DVC Fos. In contrast to CCK, gastric distension did significantly increase Fos expression in the NTS of both Veh and Cap rats, although distension-induced Fos was attenuated in Cap rats. When CCK was administered during gastric distension, it significantly enhanced NTS Fos expression in response to distension in Cap rats. Furthermore, CCK's enhancement of distension-induced Fos in Cap rats was reversed by the selective CCK-A receptor antagonist lorglumide. We conclude that CCK directly activates capsaicin-sensitive C-type vagal afferents. However, in capsaicin-resistant A-type afferents, CCK's principal action may be facilitation of responses to gastric distension.
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Affiliation(s)
- E H E M van de Wall
- Dept. of Neuroendocrinology, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands
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