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Mishra D, Richard JE, Maric I, Shevchouk OT, Börchers S, Eerola K, Krieger JP, Skibicka KP. Lateral parabrachial nucleus astrocytes control food intake. Front Endocrinol (Lausanne) 2024; 15:1389589. [PMID: 38887265 PMCID: PMC11180714 DOI: 10.3389/fendo.2024.1389589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 05/03/2024] [Indexed: 06/20/2024] Open
Abstract
Food intake behavior is under the tight control of the central nervous system. Most studies to date focus on the contribution of neurons to this behavior. However, although previously overlooked, astrocytes have recently been implicated to play a key role in feeding control. Most of the recent literature has focused on astrocytic contribution in the hypothalamus or the dorsal vagal complex. The contribution of astrocytes located in the lateral parabrachial nucleus (lPBN) to feeding behavior control remains poorly understood. Thus, here, we first investigated whether activation of lPBN astrocytes affects feeding behavior in male and female rats using chemogenetic activation. Astrocytic activation in the lPBN led to profound anorexia in both sexes, under both ad-libitum feeding schedule and after a fasting challenge. Astrocytes have a key contribution to glutamate homeostasis and can themselves release glutamate. Moreover, lPBN glutamate signaling is a key contributor to potent anorexia, which can be induced by lPBN activation. Thus, here, we determined whether glutamate signaling is necessary for lPBN astrocyte activation-induced anorexia, and found that pharmacological N-methyl D-aspartate (NMDA) receptor blockade attenuated the food intake reduction resulting from lPBN astrocyte activation. Since astrocytes have been shown to contribute to feeding control by modulating the feeding effect of peripheral feeding signals, we further investigated whether lPBN astrocyte activation is capable of modulating the anorexic effect of the gut/brain hormone, glucagon like peptide -1, as well as the orexigenic effect of the stomach hormone - ghrelin, and found that the feeding effect of both signals is modulated by lPBN astrocytic activation. Lastly, we found that lPBN astrocyte activation-induced anorexia is affected by a diet-induced obesity challenge, in a sex-divergent manner. Collectively, current findings uncover a novel role for lPBN astrocytes in feeding behavior control.
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Affiliation(s)
- Devesh Mishra
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Jennifer E. Richard
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Ivana Maric
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Department of Nutritional Sciences, Pennsylvania State University, University Park, PA, United States
| | - Olesya T. Shevchouk
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Stina Börchers
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Department of Nutritional Sciences, Pennsylvania State University, University Park, PA, United States
| | - Kim Eerola
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Jean-Philippe Krieger
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Institute of Veterinary Pharmacology and Toxicology, University of Zurich - VetSuisse, Zurich, Switzerland
| | - Karolina P. Skibicka
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Department of Nutritional Sciences, Pennsylvania State University, University Park, PA, United States
- Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, United States
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2
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Singh Alvarado J, Lutas A, Madara JC, Isaac J, Lommer C, Massengill C, Andermann ML. Transient cAMP production drives rapid and sustained spiking in brainstem parabrachial neurons to suppress feeding. Neuron 2024; 112:1416-1425.e5. [PMID: 38417435 PMCID: PMC11065603 DOI: 10.1016/j.neuron.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 12/01/2023] [Accepted: 02/01/2024] [Indexed: 03/01/2024]
Abstract
Brief stimuli can trigger longer-lasting brain states. G-protein-coupled receptors (GPCRs) could help sustain such states by coupling slow-timescale molecular signals to neuronal excitability. Brainstem parabrachial nucleus glutamatergic (PBNGlut) neurons regulate sustained brain states such as pain and express Gs-coupled GPCRs that increase cAMP signaling. We asked whether cAMP in PBNGlut neurons directly influences their excitability and effects on behavior. Both brief tail shocks and brief optogenetic stimulation of cAMP production in PBNGlut neurons drove minutes-long suppression of feeding. This suppression matched the duration of prolonged elevations in cAMP, protein kinase A (PKA) activity, and calcium activity in vivo and ex vivo, as well as sustained, PKA-dependent increases in action potential firing ex vivo. Shortening this elevation in cAMP reduced the duration of feeding suppression following tail shocks. Thus, molecular signaling in PBNGlut neurons helps prolong neural activity and behavioral states evoked by brief, salient bodily stimuli.
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Affiliation(s)
- Jonnathan Singh Alvarado
- Division of Endocrinology, Metabolism, and Diabetes, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Andrew Lutas
- Division of Endocrinology, Metabolism, and Diabetes, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA; Diabetes, Endocrinology, and Obesity Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Joseph C Madara
- Division of Endocrinology, Metabolism, and Diabetes, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Jeremiah Isaac
- Diabetes, Endocrinology, and Obesity Branch, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Caroline Lommer
- Division of Endocrinology, Metabolism, and Diabetes, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | | | - Mark L Andermann
- Division of Endocrinology, Metabolism, and Diabetes, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
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3
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Breit SN, Manandhar R, Zhang HP, Lee-Ng M, Brown DA, Tsai VWW. GDF15 enhances body weight and adiposity reduction in obese mice by leveraging the leptin pathway. Cell Metab 2023; 35:1341-1355.e3. [PMID: 37433299 DOI: 10.1016/j.cmet.2023.06.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 12/17/2022] [Accepted: 06/16/2023] [Indexed: 07/13/2023]
Abstract
GDF15 regulates its anorexic effects through the hindbrain area postrema (AP) and nucleus of the solitary tract (NTS) neurons where its receptor, glial-derived neurotrophic factor receptor alpha-like (GFRAL), is expressed. The actions of GDF15 may interact with other appetite regulators elevated in obesity, such as leptin. Here, we report that in mice with high-fat-diet-induced obesity (HFD), the combined infusion of GDF15 and leptin causes significantly greater weight and adiposity loss than either treatment alone, indicating potentiation between GDF15 and leptin. Furthermore, obese, leptin-deficient ob/ob mice are less responsive to GDF15, as are normal mice treated with a competitive leptin antagonist. GDF15 and leptin induce more hindbrain neuronal activation in HFD mice than either treatment alone does. We report extensive connections between GFRAL- and LepR-expressing neurons and find LepR knockdown in the NTS to reduce the GDF15-mediated activation of AP neurons. Overall, these findings suggest that leptin signaling pathways in the hindbrain increase GDF15's metabolic actions.
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Affiliation(s)
- Samuel N Breit
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney and University of New South Wales, Sydney, NSW 2010, Australia.
| | - Rakesh Manandhar
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney and University of New South Wales, Sydney, NSW 2010, Australia
| | - Hong-Ping Zhang
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney and University of New South Wales, Sydney, NSW 2010, Australia
| | - Michelle Lee-Ng
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney and University of New South Wales, Sydney, NSW 2010, Australia
| | - David A Brown
- Westmead Institute for Medical Research and Department of Immunopathology, Institute for Clinical Pathology and Medical Research-New South Wales Health Pathology Westmead Hospital and University of Sydney, Sydney, NSW 2145, Australia; The Centre for Allergy and Medical Research, The Westmead Institute for Medical Research, University of Sydney, Sydney, NSW 2145, Australia
| | - Vicky Wang-Wei Tsai
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney and University of New South Wales, Sydney, NSW 2010, Australia.
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4
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Alvarado JS, Lutas A, Madara JC, Isaac J, Lommer C, Andermann ML. Transient cAMP production drives rapid and sustained spiking in brainstem parabrachial neurons to suppress feeding. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.25.530033. [PMID: 36865343 PMCID: PMC9980289 DOI: 10.1101/2023.02.25.530033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Brief stimuli can trigger longer lasting brain states. G protein-coupled receptors (GPCRs) could help sustain such states by coupling slow-timescale molecular signals to neuronal excitability. Brainstem parabrachial nucleus glutamatergic neurons (PBN Glut ) regulate sustained brain states such as pain, and express G s -coupled GPCRs that increase cAMP signaling. We asked whether cAMP directly influences PBN Glut excitability and behavior. Both brief tail shocks and brief optogenetic stimulation of cAMP production in PBN Glut neurons drove minutes-long suppression of feeding. This suppression matched the duration of prolonged elevations in cAMP, Protein Kinase A (PKA), and calcium activity in vivo and in vitro. Shortening this elevation in cAMP reduced the duration of feeding suppression following tail shocks. cAMP elevations in PBN Glut neurons rapidly lead to sustained increases in action potential firing via PKA-dependent mechanisms. Thus, molecular signaling in PBN Glut neurons helps prolong neural activity and behavioral states evoked by brief, salient bodily stimuli.
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5
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Park S, Williams KW, Sohn JW. Leptin-inhibited neurons in the lateral parabrachial nucleus do not alter food intake or glucose balance. Anim Cells Syst (Seoul) 2022; 26:92-98. [PMID: 35784392 PMCID: PMC9246013 DOI: 10.1080/19768354.2022.2084159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 11/17/2022] Open
Abstract
The lateral parabrachial nucleus (LPBN) has been shown to be involved in the suppression of appetite at the pharmacological, optogenetic and chemogenetic levels. However, the signalling that mediates activation of these neurons in physiological conditions has been hindered by difficulties in segregating different cell populations in this region. Using reporter mice, we identify at the electrophysiological level the effects of an anorexic hormone, leptin, on leptin receptor (ObR)-expressing neurons in the LPBN (LPBNObR neurons). Application of leptin caused inhibition in a subpopulation of LPBNObR neurons. This effect was mediated by an increased potassium conductance and was also accompanied by a decrease in excitatory synaptic input onto these neurons. However, mimicking the inhibitory effects of leptin on LPBNObR neurons through chemogenetics led to no changes in feeding or glucose levels, which suggests that leptin action on LPBNObR neurons may not be sufficient to regulate these metabolic aspects.
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Affiliation(s)
- Seahyung Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
| | - Kevin W. Williams
- Center for Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jong-Woo Sohn
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
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6
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Watts AG, Kanoski SE, Sanchez-Watts G, Langhans W. The physiological control of eating: signals, neurons, and networks. Physiol Rev 2022; 102:689-813. [PMID: 34486393 PMCID: PMC8759974 DOI: 10.1152/physrev.00028.2020] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 08/30/2021] [Indexed: 02/07/2023] Open
Abstract
During the past 30 yr, investigating the physiology of eating behaviors has generated a truly vast literature. This is fueled in part by a dramatic increase in obesity and its comorbidities that has coincided with an ever increasing sophistication of genetically based manipulations. These techniques have produced results with a remarkable degree of cell specificity, particularly at the cell signaling level, and have played a lead role in advancing the field. However, putting these findings into a brain-wide context that connects physiological signals and neurons to behavior and somatic physiology requires a thorough consideration of neuronal connections: a field that has also seen an extraordinary technological revolution. Our goal is to present a comprehensive and balanced assessment of how physiological signals associated with energy homeostasis interact at many brain levels to control eating behaviors. A major theme is that these signals engage sets of interacting neural networks throughout the brain that are defined by specific neural connections. We begin by discussing some fundamental concepts, including ones that still engender vigorous debate, that provide the necessary frameworks for understanding how the brain controls meal initiation and termination. These include key word definitions, ATP availability as the pivotal regulated variable in energy homeostasis, neuropeptide signaling, homeostatic and hedonic eating, and meal structure. Within this context, we discuss network models of how key regions in the endbrain (or telencephalon), hypothalamus, hindbrain, medulla, vagus nerve, and spinal cord work together with the gastrointestinal tract to enable the complex motor events that permit animals to eat in diverse situations.
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Affiliation(s)
- Alan G Watts
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Scott E Kanoski
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Graciela Sanchez-Watts
- The Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, California
| | - Wolfgang Langhans
- Physiology and Behavior Laboratory, Eidgenössische Technische Hochschule-Zürich, Schwerzenbach, Switzerland
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7
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Morville T, Madsen KH, Siebner HR, Hulme OJ. Reward signalling in brainstem nuclei under fluctuating blood glucose. PLoS One 2021; 16:e0243899. [PMID: 33826633 PMCID: PMC8026025 DOI: 10.1371/journal.pone.0243899] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 12/01/2020] [Indexed: 11/18/2022] Open
Abstract
Phasic dopamine release from mid-brain dopaminergic neurons is thought to signal errors of reward prediction (RPE). If reward maximisation is to maintain homeostasis, then the value of primary rewards should be coupled to the homeostatic errors they remediate. This leads to the prediction that RPE signals should be configured as a function of homeostatic state and thus diminish with the attenuation of homeostatic error. To test this hypothesis, we collected a large volume of functional MRI data from five human volunteers on four separate days. After fasting for 12 hours, subjects consumed preloads that differed in glucose concentration. Participants then underwent a Pavlovian cue-conditioning paradigm in which the colour of a fixation-cross was stochastically associated with the delivery of water or glucose via a gustometer. This design afforded computation of RPE separately for better- and worse-than expected outcomes during ascending and descending trajectories of serum glucose fluctuations. In the parabrachial nuclei, regional activity coding positive RPEs scaled positively with serum glucose for both ascending and descending glucose levels. The ventral tegmental area and substantia nigra became more sensitive to negative RPEs when glucose levels were ascending. Together, the results suggest that RPE signals in key brainstem structures are modulated by homeostatic trajectories of naturally occurring glycaemic flux, revealing a tight interplay between homeostatic state and the neural encoding of primary reward in the human brain.
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Affiliation(s)
- Tobias Morville
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Kristoffer H. Madsen
- DTU Compute, Department of Informatics and Mathematical Modelling, Technical University of Denmark, Copenhagen, Denmark
| | - Hartwig R. Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
- Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
| | - Oliver J. Hulme
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
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8
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Le May MV, Peris-Sampedro F, Stoltenborg I, Schéle E, Bake T, Adan RAH, Dickson SL. Functional and Neurochemical Identification of Ghrelin Receptor (GHSR)-Expressing Cells of the Lateral Parabrachial Nucleus in Mice. Front Neurosci 2021; 15:633018. [PMID: 33658910 PMCID: PMC7917048 DOI: 10.3389/fnins.2021.633018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/27/2021] [Indexed: 01/28/2023] Open
Abstract
The lateral parabrachial nucleus (lPBN), located in the pons, is a well-recognized anorexigenic center harboring, amongst others, the calcitonin gene-related peptide (CGRP)-expressing neurons that play a key role. The receptor for the orexigenic hormone ghrelin (the growth hormone secretagogue receptor, GHSR) is also abundantly expressed in the lPBN and ghrelin delivery to this site has recently been shown to increase food intake and alter food choice. Here we sought to explore whether GHSR-expressing cells in the lPBN (GHSR lPBN cells) contribute to feeding control, food choice and body weight gain in mice offered an obesogenic diet, involving studies in which GHSR lPBN cells were silenced. We also explored the neurochemical identity of GHSR lPBN cells. To silence GHSR lPBN cells, Ghsr-IRES-Cre male mice were bilaterally injected intra-lPBN with a Cre-dependent viral vector expressing tetanus toxin-light chain. Unlike control wild-type littermates that significantly increased in body weight on the obesogenic diet (i.e., high-fat high-sugar free choice diet comprising chow, lard and 9% sucrose solution), the heterozygous mice with silenced GHSR lPBN cells were resistant to diet-induced weight gain with significantly lower food intake and fat weight. The lean phenotype appeared to result from a decreased food intake compared to controls and caloric efficiency was unaltered. Additionally, silencing the GHSR lPBN cells altered food choice, significantly reducing palatable food consumption. RNAscope and immunohistochemical studies of the lPBN revealed considerable co-expression of GHSR with glutamate and pituitary adenylate cyclase-activating peptide (PACAP), and much less with neurotensin, substance P and CGRP. Thus, the GHSR lPBN cells are important for diet-induced weight gain and adiposity, as well as in the regulation of food intake and food choice. Most GHSR lPBN cells were found to be glutamatergic and the majority (76%) do not belong to the well-characterized anorexigenic CGRP cell population.
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Affiliation(s)
- Marie V Le May
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Fiona Peris-Sampedro
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Iris Stoltenborg
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Erik Schéle
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Tina Bake
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Roger A H Adan
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.,Department of Translational Neuroscience, UMC Utrecht Brain Center, Utrecht University, Utrecht, Netherlands
| | - Suzanne L Dickson
- Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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9
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Gautron L. The Phantom Satiation Hypothesis of Bariatric Surgery. Front Neurosci 2021; 15:626085. [PMID: 33597843 PMCID: PMC7882491 DOI: 10.3389/fnins.2021.626085] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/06/2021] [Indexed: 01/26/2023] Open
Abstract
The excitation of vagal mechanoreceptors located in the stomach wall directly contributes to satiation. Thus, a loss of gastric innervation would normally be expected to result in abrogated satiation, hyperphagia, and unwanted weight gain. While Roux-en-Y-gastric bypass (RYGB) inevitably results in gastric denervation, paradoxically, bypassed subjects continue to experience satiation. Inspired by the literature in neurology on phantom limbs, I propose a new hypothesis in which damage to the stomach innervation during RYGB, including its vagal supply, leads to large-scale maladaptive changes in viscerosensory nerves and connected brain circuits. As a result, satiation may continue to arise, sometimes at exaggerated levels, even in subjects with a denervated or truncated stomach. The same maladaptive changes may also contribute to dysautonomia, unexplained pain, and new emotional responses to eating. I further revisit the metabolic benefits of bariatric surgery, with an emphasis on RYGB, in the light of this phantom satiation hypothesis.
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Affiliation(s)
- Laurent Gautron
- Department of Internal Medicine, Center for Hypothalamic Research, The University of Texas Southwestern Medical Center, Dallas, TX, United States
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10
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Zhang C, Yuan J, Lin Q, Li M, Wang L, Wang R, Chen X, Jiang Z, Zhu K, Chang X, Wang B, Dong J. Ghrelin in the lateral parabrachial nucleus influences the excitability of glucosensing neurons, increases food intake and body weight. Endocr Connect 2020; 9:1168-1177. [PMID: 33112816 PMCID: PMC7774750 DOI: 10.1530/ec-20-0285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 10/13/2020] [Indexed: 01/10/2023]
Abstract
Ghrelin plays a pivotal role in the regulation of food intake, body weight and energy metabolism. However, these effects of ghrelin in the lateral parabrachial nucleus (LPBN) are unexplored. C57BL/6J mice and GHSR-/- mice were implanted with cannula above the right LPBN and ghrelin was microinjected via the cannula to investigate effect of ghrelin in the LPBN. In vivo electrophysiological technique was used to record LPBN glucose-sensitive neurons to explore potential udnderlying mechanisms. Microinjection of ghrelin in LPBN significantly increased food intake in the first 3 h, while such effect was blocked by [D-Lys3]-GHRP-6 and abolished in GHSR-/- mice. LPBN ghrelin microinjection also significantly increased the firing rate of glucose-excited (GE) neurons and decreased the firing rate of glucose-inhibited (GI) neurons. Additionally, LPBN ghrelin microinjection also significantly increased c-fos expression. Chronic ghrelin administration in the LPBN resulted in significantly increased body weight gain. Meanwhile, no significant changes were observed in both mRNA and protein expression levels of UCP-1 in BAT. These results demonstrated that microinjection of ghrelin in LPBN could increase food intake through the interaction with growth hormone secretagogue receptor (GHSR) in C57BL/6J mice, and its chronic administration could also increase body weight gain. These effects might be associated with altered firing rate in the GE and GI neurons.
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Affiliation(s)
- Caishun Zhang
- Special Medicine Department, College of Basic Medicine, Qingdao University, Qingdao, China
| | - Junhua Yuan
- Special Medicine Department, College of Basic Medicine, Qingdao University, Qingdao, China
| | - Qian Lin
- Special Medicine Department, College of Basic Medicine, Qingdao University, Qingdao, China
| | - Manwen Li
- Special Medicine Department, College of Basic Medicine, Qingdao University, Qingdao, China
| | - Liuxin Wang
- Hyperbaric Oxygen Therapy Department, Yuhuangding Hospital Affiliated to Qingdao University, Yantai, China
| | - Rui Wang
- Special Medicine Department, College of Basic Medicine, Qingdao University, Qingdao, China
| | - Xi Chen
- Physiology Department, College of Basic Medicine, Qingdao University, Qingdao, China
| | - Zhengyao Jiang
- Physiology Department, College of Basic Medicine, Qingdao University, Qingdao, China
| | - Kun Zhu
- Intensive Care Unit Department, Affiliated Hospital of Qingdao University, Qingdao, China
| | - Xiaoli Chang
- Institute of Acupuncture, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Bin Wang
- Special Medicine Department, College of Basic Medicine, Qingdao University, Qingdao, China
- Medical Microbiology Department, College of Basic Medicine, Qingdao University, Qingdao, China
- Correspondence should be addressed to B Wang or J Dong: or
| | - Jing Dong
- Special Medicine Department, College of Basic Medicine, Qingdao University, Qingdao, China
- Physiology Department, College of Basic Medicine, Qingdao University, Qingdao, China
- Correspondence should be addressed to B Wang or J Dong: or
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11
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Bake T, Le May MV, Edvardsson CE, Vogel H, Bergström U, Albers MN, Skibicka KP, Farkas I, Liposits Z, Dickson SL. Ghrelin Receptor Stimulation of the Lateral Parabrachial Nucleus in Rats Increases Food Intake but not Food Motivation. Obesity (Silver Spring) 2020; 28:1503-1511. [PMID: 32627950 DOI: 10.1002/oby.22875] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/25/2020] [Accepted: 04/25/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVE The lateral parabrachial nucleus (lPBN) in the brainstem has emerged as a key area involved in feeding control that is targeted by several circulating anorexigenic hormones. Here, the objective was to determine whether the lPBN is also a relevant site for the orexigenic hormone ghrelin, inspired by studies in mice and rats showing that there is an abundance of ghrelin receptors in this area. METHODS This study first explored whether iPBN cells respond to ghrelin involving Fos mapping and electrophysiological studies in rats. Next, rats were injected acutely with ghrelin, a ghrelin receptor antagonist, or vehicle into the lPBN to investigate feeding-linked behaviors. RESULTS Curiously, ghrelin injection (intracerebroventricular or intravenous) increased Fos protein expression in the lPBN yet the predominant electrophysiological response was inhibitory. Intra-lPBN ghrelin injection increased chow or high-fat diet intake, whereas the antagonist decreased chow intake only. In a choice paradigm, intra-lPBN ghrelin increased intake of chow but not lard or sucrose. Intra-lPBN ghrelin did not alter progressive ratio lever pressing for sucrose or conditioned place preference for chocolate. CONCLUSIONS The lPBN is a novel locus from which ghrelin can alter consummatory behaviors (food intake and choice) but not appetitive behaviors (food reward and motivation).
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Affiliation(s)
- Tina Bake
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Marie V Le May
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Christian E Edvardsson
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Heike Vogel
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Ulrika Bergström
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Marjorie Nicholson Albers
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Karolina P Skibicka
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
- Department of Nutritional Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Imre Farkas
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Zsolt Liposits
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Suzanne L Dickson
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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12
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Bland T, Zhu M, Dillon C, Sahin GS, Rodriguez-Llamas JL, Appleyard SM, Wayman GA. Leptin Controls Glutamatergic Synaptogenesis and NMDA-Receptor Trafficking via Fyn Kinase Regulation of NR2B. Endocrinology 2020; 161:5678106. [PMID: 31840160 PMCID: PMC7015580 DOI: 10.1210/endocr/bqz030] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 12/10/2019] [Indexed: 01/13/2023]
Abstract
Activation of the leptin receptor, LepRb, by the adipocytokine/neurotrophic factor leptin in the central nervous system has procognitive and antidepressive effects. Leptin has been shown to increase glutamatergic synaptogenesis in multiple brain regions. In contrast, mice that have a mutation in the LepRb gene show abnormal synapse development in the hippocampus as well as deficits in cognition and increased depressive-like symptoms. Leptin increases glutamatergic synaptogenesis, in part, through enhancement of N-methyl-D-aspartic acid (NMDA) receptor function; yet the underlying signaling pathway is not known. In this study, we examine how leptin regulates surface expression of NR2B-containing NMDA receptors in hippocampal neurons. Leptin stimulation increases NR2BY1472 phosphorylation, which is inhibited by the Src family kinase inhibitor, PP1. Moreover, we show that Fyn, a member of the Src family kinases, is required for leptin-stimulated NR2BY1472 phosphorylation. Furthermore, inhibiting Y1472 phosphorylation with either a dominant negative Fyn mutant or an NR2B mutant that lacks the phosphorylation site (NR2BY1472F) blocks leptin-stimulated synaptogenesis. Additionally, we show that LepRb forms a complex with NR2B and Fyn. Taken together, these findings expand our knowledge of the LepRb interactome and the mechanisms by which leptin stimulates glutamatergic synaptogenesis in the developing hippocampus. Comprehending these mechanisms is key for understanding dendritic spine development and synaptogenesis, alterations of which are associated with many neurological disorders.
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Affiliation(s)
- Tyler Bland
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Mingyan Zhu
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Crystal Dillon
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Gulcan Semra Sahin
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Jose Luis Rodriguez-Llamas
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Suzanne M Appleyard
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
| | - Gary A Wayman
- Program in Neuroscience, Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington
- Correspondence: Gary A. Wayman, Department of Integrative Physiology and Neuroscience, Program in Neuroscience, Washington State University, Pullman Washington 99164. E-mail:
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13
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Alhadeff AL, Conway SM, Ong ZY, Wald HS, Roitman MF, Grill HJ. Central leptin signaling transmits positive valence. Brain Res 2019; 1724:146441. [PMID: 31513793 DOI: 10.1016/j.brainres.2019.146441] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/04/2019] [Accepted: 09/06/2019] [Indexed: 01/06/2023]
Abstract
Hunger resulting from food deprivation is associated with negative affect. This is supported by recent evidence showing that hunger-sensitive neurons drive feeding through a negative valence teaching signal. However, the complementary hypothesis that hormonal signals of energy surfeit counteract this negative valence, or even transmit positive valence, has received less attention. The adipose-derived hormone leptin signals in proportion to fat mass, is an indicator of energy surplus, and reduces food intake. Here, we showed that centrally-delivered leptin reduced food intake and conditioned a place preference in food-restricted as well as ad libitum fed rats. In contrast, leptin did not reduce food intake nor condition a place preference in obese rats, likely due to leptin resistance. Despite a well-known role for hindbrain leptin receptor signaling in energy balance control, hindbrain leptin delivery did not condition a place preference in food-restricted rats, suggesting that leptin acting in midbrain or forebrain sites mediates place preference conditioning. Supporting the hypothesis that leptin signaling induces a positive affective state, leptin also decreased the threshold for ventral tegmental area brain stimulation reward. Together, these data suggest that leptin signaling is intrinsically preferred, and support the view that signals of energy surfeit are associated with positive affect. Harnessing the positive valence of signals such as leptin may attenuate the negative affect associated with hunger, providing a compelling new approach for weight loss maintenance.
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Affiliation(s)
- Amber L Alhadeff
- Department of Biology, University of Pennsylvania, Philadelphia, PA, United States; Department of Psychology, University of Pennsylvania, Philadelphia, PA, United States.
| | - Sineadh M Conway
- Department of Psychology, University of Illinois at Chicago, Chicago, IL, United States
| | - Zhi Yi Ong
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, United States
| | - Hallie S Wald
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, United States
| | - Mitchell F Roitman
- Department of Psychology, University of Illinois at Chicago, Chicago, IL, United States
| | - Harvey J Grill
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, United States
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14
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Feeding circuit development and early-life influences on future feeding behaviour. Nat Rev Neurosci 2019; 19:302-316. [PMID: 29662204 DOI: 10.1038/nrn.2018.23] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A wide range of maternal exposures - undernutrition, obesity, diabetes, stress and infection - are associated with an increased risk of metabolic disease in offspring. Developmental influences can cause persistent structural changes in hypothalamic circuits regulating food intake in the service of energy balance. The physiological relevance of these alterations has been called into question because maternal impacts on daily caloric intake do not persist to adulthood. Recent behavioural and epidemiological studies in humans provide evidence that the relative contribution of appetitive traits related to satiety, reward and the emotional aspects of food intake regulation changes across the lifespan. This Opinion article outlines a neurodevelopmental framework to explore the possibility that crosstalk between developing circuits regulating different modalities of food intake shapes future behavioural responses to environmental challenges.
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15
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Mishra D, Richard JE, Maric I, Porteiro B, Häring M, Kooijman S, Musovic S, Eerola K, López-Ferreras L, Peris E, Grycel K, Shevchouk OT, Micallef P, Olofsson CS, Wernstedt Asterholm I, Grill HJ, Nogueiras R, Skibicka KP. Parabrachial Interleukin-6 Reduces Body Weight and Food Intake and Increases Thermogenesis to Regulate Energy Metabolism. Cell Rep 2019; 26:3011-3026.e5. [PMID: 30865890 PMCID: PMC6418345 DOI: 10.1016/j.celrep.2019.02.044] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 12/15/2018] [Accepted: 02/12/2019] [Indexed: 02/07/2023] Open
Abstract
Chronic low-grade inflammation and increased serum levels of the cytokine IL-6 accompany obesity. For brain-produced IL-6, the mechanisms by which it controls energy balance and its role in obesity remain unclear. Here, we show that brain-produced IL-6 is decreased in obese mice and rats in a neuroanatomically and sex-specific manner. Reduced IL-6 mRNA localized to lateral parabrachial nucleus (lPBN) astrocytes, microglia, and neurons, including paraventricular hypothalamus-innervating lPBN neurons. IL-6 microinjection into lPBN reduced food intake and increased brown adipose tissue (BAT) thermogenesis in male lean and obese rats by increasing thyroid and sympathetic outflow to BAT. Parabrachial IL-6 interacted with leptin to reduce feeding. siRNA-mediated reduction of lPBN IL-6 leads to increased weight gain and adiposity, reduced BAT thermogenesis, and increased food intake. Ambient cold exposure partly normalizes the obesity-induced suppression of lPBN IL-6. These results indicate that lPBN-produced IL-6 regulates feeding and metabolism and pinpoints (patho)physiological contexts interacting with lPBN IL-6.
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Affiliation(s)
- Devesh Mishra
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Jennifer E Richard
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Ivana Maric
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Begona Porteiro
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain
| | - Martin Häring
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Sander Kooijman
- Department of Medicine, Division of Endocrinology, Leiden University Medical Center, 2333 ZA Leiden, the Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, 2333 ZA Leiden, the Netherlands
| | - Saliha Musovic
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Kim Eerola
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Lorena López-Ferreras
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Eduard Peris
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Katarzyna Grycel
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Olesya T Shevchouk
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Peter Micallef
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Charlotta S Olofsson
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Ingrid Wernstedt Asterholm
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Harvey J Grill
- Lynch Laboratory, Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ruben Nogueiras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Spain
| | - Karolina P Skibicka
- Department of Physiology and Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden.
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16
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Augustine V, Gokce SK, Oka Y. Peripheral and Central Nutrient Sensing Underlying Appetite Regulation. Trends Neurosci 2018; 41:526-539. [PMID: 29914721 DOI: 10.1016/j.tins.2018.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/30/2018] [Accepted: 05/01/2018] [Indexed: 12/11/2022]
Abstract
The precise regulation of fluid and energy homeostasis is essential for survival. It is well appreciated that ingestive behaviors are tightly regulated by both peripheral sensory inputs and central appetite signals. With recent neurogenetic technologies, considerable progress has been made in our understanding of basic taste qualities, the molecular and/or cellular basis of taste sensing, and the central circuits for thirst and hunger. In this review, we first highlight the functional similarities and differences between mammalian and invertebrate taste processing. We then discuss how central thirst and hunger signals interact with peripheral sensory signals to regulate ingestive behaviors. We finally indicate some of the directions for future research.
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Affiliation(s)
- Vineet Augustine
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Sertan Kutal Gokce
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Yuki Oka
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
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17
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Ram A, Lo AW. Is Smaller Better? A Proposal to Use Bacteria For Neuroscientific Modeling. Front Comput Neurosci 2018; 12:7. [PMID: 29527158 PMCID: PMC5829041 DOI: 10.3389/fncom.2018.00007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/17/2018] [Indexed: 11/24/2022] Open
Abstract
Bacteria are easily characterizable model organisms with an impressively complicated set of abilities. Among them is quorum sensing, a cell-cell signaling system that may have a common evolutionary origin with eukaryotic cell-cell signaling. The two systems are behaviorally similar, but quorum sensing in bacteria is more easily studied in depth than cell-cell signaling in eukaryotes. Because of this comparative ease of study, bacterial dynamics are also more suited to direct interpretation than eukaryotic dynamics, e.g., those of the neuron. Here we review literature on neuron-like qualities of bacterial colonies and biofilms, including ion-based and hormonal signaling, and a phenomenon similar to the graded action potential. This suggests that bacteria could be used to help create more accurate and detailed biological models in neuroscientific research. More speculatively, bacterial systems may be considered an analog for neurons in biologically based computational research, allowing models to better harness the tremendous ability of biological organisms to process information and make decisions.
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Affiliation(s)
- Archana Ram
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Andrew W. Lo
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, United States
- Sloan School of Management, Massachusetts Institute of Technology, Cambridge, MA, United States
- Laboratory for Financial Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, United States
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18
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Kim KS, Seeley RJ, Sandoval DA. Signalling from the periphery to the brain that regulates energy homeostasis. Nat Rev Neurosci 2018; 19:185-196. [DOI: 10.1038/nrn.2018.8] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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19
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20
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Ong ZY, Bongiorno DM, Hernando MA, Grill HJ. Effects of Endogenous Oxytocin Receptor Signaling in Nucleus Tractus Solitarius on Satiation-Mediated Feeding and Thermogenic Control in Male Rats. Endocrinology 2017; 158:2826-2836. [PMID: 28575174 PMCID: PMC5659667 DOI: 10.1210/en.2017-00200] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/24/2017] [Indexed: 12/15/2022]
Abstract
Central oxytocin receptor (OT-R) signaling reduces food intake and increases energy expenditure, but the central sites and mechanisms mediating these effects are unresolved. We showed previously that pharmacological activation of OT-R in hindbrain/nucleus tractus solitarius (NTS) amplifies the intake-inhibitory effects of gastrointestinal (GI) satiation signals. Unexplored were the energetic effects of hindbrain OT-R agonism and the physiological relevance of NTS OT-R signaling on food intake and energy expenditure control. Using a virally mediated OT-R knockdown (KD) strategy and a range of behavioral paradigms, this study examined the role of endogenous NTS OT-R signaling on satiation-mediated food intake inhibition and thermogenic control. Results showed that, compared with controls, NTS OT-R KD rats consumed larger meals, were less responsive to the intake-inhibitory effects of a self-ingested preload, and consumed more chow following a 24-hour fast. These data indicate that NTS OT-R signaling is necessary for normal satiation control. Whereas both control and NTS OT-R KD rats increased core temperature following high-fat diet maintenance (relative to chow maintenance), the percent increase in core temperature was greater in control compared with NTS OT-R KD rats during the light cycle. Hindbrain oxytocin agonist delivery increased core temperature in both control and NTS OT-R KD rats and the percent increase relative to vehicle treatment was not significantly different between groups. Together, data reveal a critical role for endogenous NTS OT-R signaling in mediating the intake-inhibitory effects of endogenous GI satiation signals and in diet-induced thermogenesis.
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Affiliation(s)
- Zhi Yi Ong
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Diana M. Bongiorno
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Mary Ann Hernando
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Harvey J. Grill
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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21
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Endogenous Glucagon-like Peptide-1 Receptor Signaling in the Nucleus Tractus Solitarius is Required for Food Intake Control. Neuropsychopharmacology 2017; 42:1471-1479. [PMID: 27782127 PMCID: PMC5436110 DOI: 10.1038/npp.2016.246] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 09/30/2016] [Accepted: 10/13/2016] [Indexed: 12/12/2022]
Abstract
Alhough the glucagon-like peptide-1 (GLP-1) system is critical to energy balance control and is a target for obesity pharmacotherapies, the receptor-population-mediating effects of endogenous GLP-1 signaling are not fully understood. To address this, we developed a novel adeno-associated virus (AAV-GLP-1R) that utilizes short hairpin RNA to chronically knock down GLP-1 receptors (GLP-1R) in rats. As pharmacological studies highlight the hindbrain nucleus tractus solitarius (NTS) as a brain region important for GLP-1R-mediated effects on energy balance, AAV-GLP-1R was injected into the NTS to examine the role of endogenous NTS GLP-1R signaling in energy balance control. Chow intake and meal size were significantly increased following chronic NTS GLP-1R knockdown. In addition, NTS GLP-1R knockdown significantly increased self-administration of palatable food under both fixed and progressive ratio schedules of reinforcement. Collectively, these data demonstrate that endogenous NTS GLP-1R signaling is required for the control of food intake and motivation to feed, and provide a new strategy to investigate the importance of distinct GLP-1R populations in the control of a variety of functions.
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22
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Yuan JH, Chen X, Dong J, Zhang D, Song K, Zhang Y, Wu GB, Hu XH, Jiang ZY, Chen P. Nesfatin-1 in the Lateral Parabrachial Nucleus Inhibits Food Intake, Modulates Excitability of Glucosensing Neurons, and Enhances UCP1 Expression in Brown Adipose Tissue. Front Physiol 2017; 8:235. [PMID: 28484396 PMCID: PMC5401881 DOI: 10.3389/fphys.2017.00235] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 04/03/2017] [Indexed: 01/11/2023] Open
Abstract
Nesfatin-1, an 82-amino acid neuropeptide, has been shown to induce anorexia and energy expenditure. Food intake is decreased in ad libitum-fed rats following injections of nesfatin-1 into the lateral, third, or fourth ventricles of the brain. Although the lateral parabrachial nucleus (LPBN) is a key regulator of feeding behavior and thermogenesis, the role of nesfatin-1 in this structure has not yet been delineated. We found that intra-LPBN microinjections of nesfatin-1 significantly reduced nocturnal cumulative food intake and average meal sizes without affecting meal numbers in rats. Because glucose sensitive neurons are involved in glucoprivic feeding and glucose homeostasis, we examined the effect of nesfatin-1 on the excitability of LPBN glucosensing neurons. In vivo electrophysiological recordings from LPBN glucose sensitive neurons showed that nesfatin-1 (1.5 × 10-8 M) excited most of the glucose-inhibited neurons. Chronic administration of nesfatin-1 into the LPBN of rats reduced body weight gain and enhanced the expression of uncoupling protein 1 (UCP1) in brown adipose tissue (BAT) over a 10-day period. Furthermore, the effects of nesfatin-1 on food intake, body weight, and BAT were attenuated by treatment with the melanocortin antagonist SHU9119. These results demonstrate that nesfatin-1 in LPBN inhibited food intake, modulated excitability of glucosensing neurons and enhanced UCP1 expression in BAT via the melanocortin system.
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Affiliation(s)
- Jun-hua Yuan
- Special Medicine Department, Medical College, Qingdao UniversityQingdao, China
| | - Xi Chen
- Physiology Department, Medical College, Qingdao UniversityQingdao, China
| | - Jing Dong
- Special Medicine Department, Medical College, Qingdao UniversityQingdao, China
- Physiology Department, Medical College, Qingdao UniversityQingdao, China
| | - Di Zhang
- Special Medicine Department, Medical College, Qingdao UniversityQingdao, China
| | - Kun Song
- Clinical Medicine Department, Medical College, Qingdao UniversityQingdao, China
| | - Yue Zhang
- Clinical Medicine Department, Medical College, Qingdao UniversityQingdao, China
| | - Guang-bo Wu
- Clinical Medicine Department, Medical College, Qingdao UniversityQingdao, China
| | - Xi-hao Hu
- Clinical Medicine Department, Medical College, Qingdao UniversityQingdao, China
| | - Zheng-yao Jiang
- Physiology Department, Medical College, Qingdao UniversityQingdao, China
| | - Peng Chen
- Department of Human Anatomy, Histology and Embryology, Qingdao UniversityQingdao, China
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23
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Clemensson EKH, Clemensson LE, Fabry B, Riess O, Nguyen HP. Further investigation of phenotypes and confounding factors of progressive ratio performance and feeding behavior in the BACHD rat model of Huntington disease. PLoS One 2017; 12:e0173232. [PMID: 28273120 PMCID: PMC5342229 DOI: 10.1371/journal.pone.0173232] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/18/2017] [Indexed: 01/29/2023] Open
Abstract
Huntington disease is an inherited neurodegenerative disorder characterized by motor, cognitive, psychiatric and metabolic symptoms. We recently published a study describing that the BACHD rat model of HD shows an obesity phenotype, which might affect their motivation to perform food-based behavioral tests. Further, we argued that using a food restriction protocol based on matching BACHD and wild type rats' food consumption rates might resolve these motivational differences. In the current study, we followed up on these ideas in a longitudinal study of the rats' performance in a progressive ratio test. We also investigated the phenotype of reduced food consumption rate, which is typically seen in food-restricted BACHD rats, in greater detail. In line with our previous study, the BACHD rats were less motivated to perform the progressive ratio test compared to their wild type littermates, although the phenotype was no longer present when the rats' food consumption rates had been matched. However, video analysis of food consumption tests suggested that the reduced consumption rate found in the BACHD rats was not entirely based on differences in hunger, but likely involved motoric impairments. Thus, restriction protocols based on food consumption rates are not appropriate when working with BACHD rats. As an alternative, we suggest that studies where BACHD rats are used should investigate how the readouts of interest are affected by motivational differences, and use appropriate control tests to avoid misleading results. In addition, we show that BACHD rats display distinct behavioral changes in their progressive ratio performance, which might be indicative of striatal dysfunction.
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Affiliation(s)
- Erik Karl Håkan Clemensson
- Institute of Medical Genetics and Applied Genomics, Tuebingen, Tuebingen, Germany
- Centre for Rare Diseases, Tuebingen, Tuebingen, Germany
| | - Laura Emily Clemensson
- Institute of Medical Genetics and Applied Genomics, Tuebingen, Tuebingen, Germany
- Centre for Rare Diseases, Tuebingen, Tuebingen, Germany
- QPS Austria, Grambach, Austria
| | | | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, Tuebingen, Tuebingen, Germany
- Centre for Rare Diseases, Tuebingen, Tuebingen, Germany
| | - Huu Phuc Nguyen
- Institute of Medical Genetics and Applied Genomics, Tuebingen, Tuebingen, Germany
- Centre for Rare Diseases, Tuebingen, Tuebingen, Germany
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24
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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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25
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Gerth AI, Alhadeff AL, Grill HJ, Roitman MF. Regional influence of cocaine on evoked dopamine release in the nucleus accumbens core: A role for the caudal brainstem. Brain Res 2016; 1655:252-260. [PMID: 27789280 DOI: 10.1016/j.brainres.2016.10.022] [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: 08/03/2016] [Revised: 10/20/2016] [Accepted: 10/22/2016] [Indexed: 12/30/2022]
Abstract
Cocaine increases dopamine concentration in the nucleus accumbens through competitive binding to the dopamine transporter (DAT). However, it also increases the frequency of dopamine release events, a finding that cannot be explained by action at the DAT alone. Rather, this effect may be mediated by cocaine-induced modulation of brain regions that project to dopamine neurons. To explore regional contributions of cocaine to dopamine signaling, we administered cocaine to the lateral or fourth ventricles and compared the effects on dopamine release in the nucleus accumbens evoked by electrical stimulation of the ventral tegmental area to that of systemically-delivered cocaine. Stimulation trains caused a sharp rise in dopamine followed by a slower return to baseline. The magnitude of dopamine release ([DA]max) as well as the latency to decay to fifty percent of the maximum (t(1/2); index of DAT activity) by each stimulation train were recorded. All routes of cocaine delivery caused an increase in [DA]max; only systemic cocaine caused an increase in t(1/2). Importantly, these data are the first to show that hindbrain (fourth ventricle)-delivered cocaine modulates phasic dopamine signaling. Fourth ventricular cocaine robustly increased cFos immunoreactivity in the nucleus of the solitary tract (NTS), suggesting a neural substrate for hindbrain cocaine-mediated effects on [DA]max. Together, the data demonstrate that cocaine-induced effects on phasic dopamine signaling are mediated via actions throughout the brain including the hindbrain.
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Affiliation(s)
- Ashlynn I Gerth
- Department of Psychology, University of Illinois at Chicago, 1007 W Harrison St, Chicago, IL 60607, USA
| | - Amber L Alhadeff
- Department of Psychology, University of Pennsylvania, 3720 Walnut St, Philadelphia, PA 19104, USA
| | - Harvey J Grill
- Department of Psychology, University of Pennsylvania, 3720 Walnut St, Philadelphia, PA 19104, USA
| | - Mitchell F Roitman
- Department of Psychology, University of Illinois at Chicago, 1007 W Harrison St, Chicago, IL 60607, USA.
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Campos CA, Bowen AJ, Schwartz MW, Palmiter RD. Parabrachial CGRP Neurons Control Meal Termination. Cell Metab 2016; 23:811-20. [PMID: 27166945 PMCID: PMC4867080 DOI: 10.1016/j.cmet.2016.04.006] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 02/17/2016] [Accepted: 04/04/2016] [Indexed: 01/09/2023]
Abstract
The lateral parabrachial nucleus is a conduit for visceral signals that cause anorexia. We previously identified a subset of neurons located in the external lateral parabrachial nucleus (PBel) that express calcitonin gene-related peptide (CGRP) and inhibit feeding when activated by illness mimetics. We report here that in otherwise normal mice, functional inactivation of CGRP neurons markedly increases meal size, with meal frequency being reduced in a compensatory manner, and renders mice insensitive to the anorexic effects of meal-related satiety peptides. Furthermore, CGRP neurons are directly innervated by orexigenic hypothalamic AgRP neurons, and photostimulation of AgRP fibers supplying the PBel delays satiation by inhibiting CGRP neurons, thereby contributing to AgRP-driven hyperphagia. By establishing a role for CGRP neurons in the control of meal termination and as a downstream mediator of feeding elicited by AgRP neurons, these findings identify a node in which hunger and satiety circuits interact to control feeding behavior.
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Affiliation(s)
- Carlos A Campos
- Department of Biochemistry, Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
| | - Anna J Bowen
- Department of Biochemistry, Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | - Michael W Schwartz
- Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Richard D Palmiter
- Department of Biochemistry, Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA.
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Singh O, Kumar S, Singh U, Kumar V, Lechan RM, Singru PS. Cocaine- and amphetamine-regulated transcript peptide (CART) in the brain of zebra finch,Taeniopygia guttata: Organization, interaction with neuropeptide Y, and response to changes in energy status. J Comp Neurol 2016; 524:3014-41. [DOI: 10.1002/cne.24004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 03/21/2016] [Accepted: 03/24/2016] [Indexed: 01/21/2023]
Affiliation(s)
- Omprakash Singh
- School of Biological Sciences; National Institute of Science Education and Research (NISER)-Bhubaneswar; Odisha India
| | - Santosh Kumar
- School of Biological Sciences; National Institute of Science Education and Research (NISER)-Bhubaneswar; Odisha India
| | - Uday Singh
- School of Biological Sciences; National Institute of Science Education and Research (NISER)-Bhubaneswar; Odisha India
| | - Vinod Kumar
- DST-IRHPA Centre for Excellence in Biological Rhythms Research and Indo-US Centre for Biological Timing, Department of Zoology; University of Delhi; Delhi India
| | - Ronald M. Lechan
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Tupper Research Institute; Tufts Medical Center; Boston Massachusetts USA
- Department of Neuroscience; Tufts University School of Medicine; Boston Massachusetts USA
| | - Praful S. Singru
- School of Biological Sciences; National Institute of Science Education and Research (NISER)-Bhubaneswar; Odisha India
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Alhadeff AL, Golub D, Hayes MR, Grill HJ. Peptide YY signaling in the lateral parabrachial nucleus increases food intake through the Y1 receptor. Am J Physiol Endocrinol Metab 2015; 309:E759-66. [PMID: 26330345 PMCID: PMC4609877 DOI: 10.1152/ajpendo.00346.2015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 08/26/2015] [Indexed: 11/22/2022]
Abstract
Although central PYY delivery potently increases food intake, the sites of action and mechanisms mediating these hyperphagic effects are not fully understood. The present studies investigate the contribution of lateral parabrachial nucleus (lPBN) PYY-Y receptor signaling to food intake control, as lPBN neurons express Y receptors and receive PYY fibers and are known to integrate circulating and visceral sensory signals to regulate energy balance. Immunohistochemical results identified a subpopulation of gigantocellular reticular nucleus PYY-producing neurons that project monosynaptically to the lPBN, providing an endogenous source of PYY to the lPBN. lPBN microinjection of PYY-(1-36) or PYY-(3-36) markedly increased food intake by increasing meal size. To determine which receptors mediate these behavioral results, we first performed quantitative real-time PCR to examine the relative levels of Y receptor expression in lPBN tissue. Gene expression analyses revealed that, while Y1, Y2, and Y5 receptors are each expressed in lPBN tissue, Y1 receptor mRNA is expressed at fivefold higher levels than the others. Furthermore, behavioral/pharmacological results demonstrated that the hyperphagic effects of PYY-(3-36) were eliminated by lPBN pretreatment with a selective Y1 receptor antagonist. Together, these results highlight the lPBN as a novel site of action for the intake-stimulatory effects of central PYY-Y1 receptor signaling.
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Affiliation(s)
- Amber L Alhadeff
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Danielle Golub
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Matthew R Hayes
- Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Harvey J Grill
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania; and
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Subramanian HH, Arun M, Silburn PA, Holstege G. Motor organization of positive and negative emotional vocalization in the cat midbrain periaqueductal gray. J Comp Neurol 2015; 524:1540-57. [PMID: 26235936 DOI: 10.1002/cne.23869] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 07/22/2015] [Accepted: 07/24/2015] [Indexed: 12/25/2022]
Abstract
Neurochemical microstimulation in different parts of the midbrain periaqueductal gray (PAG) in the cat generates four different types of vocalization, mews, howls, cries, and hisses. Mews signify positive vocal expression, whereas howls, hisses, and cries signify negative vocal communications. Mews were generated in the lateral column of the intermediate PAG and howls and hisses in the ventrolateral column of the intermediate PAG. Cries were generated in two regions, the lateral column of the rostral PAG and the ventrolateral column of the caudal PAG. To define the specific motor patterns belonging to mews, howls, and cries, the following muscles were recorded during these vocalizations: larynx (cricothyroid, thyroarytenoid, and posterior cricoarytenoid), tongue (genioglossus), jaw (digastric), and respiration (diaphragm, internal intercostal, external abdominal oblique, and internal abdominal oblique) muscles. Furthermore, the frequency, intensity, activation cascades, and turns and amplitude analyses of the electromyograms (EMGs) during these vocalizations were analyzed. The results show that each type of vocalization consists of a specific, circumscribed motor coordination. The nucleus retroambiguus (NRA) in the caudal medulla serves as the final premotor interneuronal output system for vocalization. NRA neurochemical microstimulation also generated vocalizations (guttural sounds). Analysis of the EMGs demonstrated that these vocalizations consist of only small parts of the emotional voalizations generated by neurochemical stimulation in the PAG. These results demonstrate that motor organization of positive and negative emotional vocal expressions are segregated in the PAG and that the PAG uses the NRA as a tool to gain access to the motoneurons generating vocalization.
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Affiliation(s)
| | - Mridula Arun
- Asia-Pacific Centre for Neuromodulation, Queensland Brain Institute.,School of Biomedical Sciences, The University of Queensland, Brisbane, 4072, Australia
| | - Peter A Silburn
- Asia-Pacific Centre for Neuromodulation, Queensland Brain Institute
| | - Gert Holstege
- Asia-Pacific Centre for Neuromodulation, Queensland Brain Institute
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Abstract
Obesity ensues from an imbalance between energy intake and expenditure that results from gene-environment interactions, which favour a positive energy balance. A society that promotes unhealthy food and encourages sedentary lifestyle (that is, an obesogenic environment) has become a major contributory factor in excess fat deposition in individuals predisposed to obesity. Energy homeostasis relies upon control of energy intake as well as expenditure, which is in part determined by the themogenesis of brown adipose tissue and mediated by the sympathetic nervous system. Several areas of the brain that constitute cognitive and autonomic brain systems, which in turn form networks involved in the control of appetite and thermogenesis, also contribute to energy homeostasis. These networks include the dopamine mesolimbic circuit, as well as the opioid, endocannabinoid and melanocortin systems. The activity of these networks is modulated by peripheral factors such as hormones derived from adipose tissue and the gut, which access the brain via the circulation and neuronal signalling pathways to inform the central nervous system about energy balance and nutritional status. In this Review, I focus on the determinants of energy homeostasis that have emerged as prominent factors relevant to obesity.
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Affiliation(s)
- Denis Richard
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, 2725 Chemin Sainte-Foy, Québec, QC G1V 4G5, Canada
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Fam BC, Sgambellone R, Ruan Z, Proietto J, Andrikopoulos S. Contribution of the hypothalamus and gut to weight gain susceptibility and resistance in mice. J Endocrinol 2015; 225:191-204. [PMID: 25934705 DOI: 10.1530/joe-15-0131] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/30/2015] [Indexed: 12/15/2022]
Abstract
Obesity susceptibility in humans and in rodent strains varies in response to the consumption of high-energy density (HED) diets. However, the exact mechanism(s) involved in this susceptibility remain(s) unresolved. The aim of the present study was to gain greater insight into this susceptibility by using C57BL/6J (B6) mice that were separated into obesity-prone (diet-induced obese (DIO)) and obesity-resistant (diet-induced resistant (DR)) groups following an HED diet for 6 weeks. Physiological, biochemical and gene expression assessments of energy balance were performed in the DIO and DR mice on an HED diet and chow-fed mice. The increased weight gain of the DIO mice as compared to the DR mice was associated with increased energy intake and higher plasma leptin and adiponectin levels but not with reduced physical activity or resting energy expenditure. Hypothalamic Pomc gene expression was elevated, but there were no changes in Npy or Agrp expression. Adipose tissue leptin and adiponectin gene expression were significantly reduced in the DIO group as compared to the DR group. Interestingly, ileum expression of G protein-coupled receptor (Gpr) 40 (Gpr40) was significantly increased, whereas Gpr120, Gpr119, Gpr41, and glucagon-like peptide 1 (Glp1) were reduced. Contrastingly, the lower weight gain of the DR group was associated with elevated adipose tissue leptin and adiponectin gene expression, but there were no differences in plasma hormone or hypothalamic gene expression levels as compared to chow-fed mice. Therefore, the present data demonstrate that susceptibility and resistance to diet-induced weight gain in B6 mice appears to be predominantly driven by peripheral rather than hypothalamic modifications, and changes in gut-specific receptors are a potentially important contributor to this variation.
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Affiliation(s)
- Barbara C Fam
- Department of Medicine (Austin Health) Austin Hospital, The University of Melbourne, Level 7, Lance Townsend Building, Studley Road, Heidelberg, Victoria 3084, Australia
| | - Rebecca Sgambellone
- Department of Medicine (Austin Health) Austin Hospital, The University of Melbourne, Level 7, Lance Townsend Building, Studley Road, Heidelberg, Victoria 3084, Australia
| | - Zheng Ruan
- Department of Medicine (Austin Health) Austin Hospital, The University of Melbourne, Level 7, Lance Townsend Building, Studley Road, Heidelberg, Victoria 3084, Australia
| | - Joseph Proietto
- Department of Medicine (Austin Health) Austin Hospital, The University of Melbourne, Level 7, Lance Townsend Building, Studley Road, Heidelberg, Victoria 3084, Australia
| | - Sofianos Andrikopoulos
- Department of Medicine (Austin Health) Austin Hospital, The University of Melbourne, Level 7, Lance Townsend Building, Studley Road, Heidelberg, Victoria 3084, Australia
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