1
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Chesters RA, Zhu J, Coull BM, Baidoe-Ansah D, Baumer L, Palm L, Klinghammer N, Chen S, Hahm A, Yagoub S, Cantacorps L, Bernardi D, Ritter K, Lippert RN. Fasting-induced activity changes in MC3R neurons of the paraventricular nucleus of the thalamus. Life Sci Alliance 2024; 7:e202402754. [PMID: 39107065 PMCID: PMC11303869 DOI: 10.26508/lsa.202402754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 07/26/2024] [Accepted: 07/29/2024] [Indexed: 08/09/2024] Open
Abstract
The brain controls energy homeostasis by regulating food intake through signaling within the melanocortin system. Whilst we understand the role of the hypothalamus within this system, how extra-hypothalamic brain regions are involved in controlling energy balance remains unclear. Here we show that the melanocortin 3 receptor (MC3R) is expressed in the paraventricular nucleus of the thalamus (PVT). We tested whether fasting would change the activity of MC3R neurons in this region by assessing the levels of c-Fos and pCREB as neuronal activity markers. We determined that overnight fasting causes a significant reduction in pCREB levels within PVT-MC3R neurons. We then questioned whether perturbation of MC3R signaling, during fasting, would result in altered refeeding. Using chemogenetic approaches, we show that modulation of MC3R activity, during the fasting period, does not impact body weight regain or total food intake in the refeeding period. However, we did observe significant differences in the pattern of feeding-related behavior. These findings suggest that the PVT is a region where MC3R neurons respond to energy deprivation and modulate refeeding behavior.
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Affiliation(s)
- Robert A Chesters
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
| | - Jiajie Zhu
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
- NeuroCure Cluster of Excellence, Charité-Universitätsmedizin, Berlin, Germany
| | - Bethany M Coull
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
- NeuroCure Cluster of Excellence, Charité-Universitätsmedizin, Berlin, Germany
| | - David Baidoe-Ansah
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
- NeuroCure Cluster of Excellence, Charité-Universitätsmedizin, Berlin, Germany
| | - Lea Baumer
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
| | - Lydia Palm
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
| | - Niklas Klinghammer
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
| | - Seve Chen
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
| | - Anneke Hahm
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
| | - Selma Yagoub
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
| | - Lídia Cantacorps
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Daniel Bernardi
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
| | - Katrin Ritter
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
| | - Rachel N Lippert
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition https://ror.org/05xdczy51, Nuthetal, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
- NeuroCure Cluster of Excellence, Charité-Universitätsmedizin, Berlin, Germany
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2
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Gozen O, Aypar B, Ozturk Bintepe M, Tuzcu F, Balkan B, Koylu EO, Kanit L, Keser A. Chronic Nicotine Consumption and Withdrawal Regulate Melanocortin Receptor, CRF, and CRF Receptor mRNA Levels in the Rat Brain. Brain Sci 2024; 14:63. [PMID: 38248278 PMCID: PMC10813117 DOI: 10.3390/brainsci14010063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 01/23/2024] Open
Abstract
Alterations in the various neuropeptide systems in the mesocorticolimbic circuitry have been implicated in negative effects associated with drug withdrawal. The corticotropin-releasing factor (CRF) and α-melanocyte-stimulating hormone are two peptides that may be involved. This study investigated the regulatory effects of chronic nicotine exposure and withdrawal on the mRNA levels of melanocortin receptors (MC3R, MC4R), CRF, and CRF receptors (CRFR1 and CRFR2) expressed in the mesocorticolimbic system. Rats were given drinking water with nicotine or without nicotine (control group) for 12 weeks, after which they continued receiving nicotine (chronic exposure) or were withdrawn from nicotine for 24 or 48 h. The animals were decapitated following behavioral testing for withdrawal signs. Quantitative real-time PCR analysis demonstrated that nicotine exposure (with or without withdrawal) increased levels of CRF and CRFR1 mRNA in the amygdala, CRF mRNA in the medial prefrontal cortex, and CRFR1 mRNA in the septum. Nicotine withdrawal also enhanced MC3R and MC4R mRNA levels in different brain regions, while chronic nicotine exposure was associated with increased MC4R mRNA levels in the nucleus accumbens. These results suggest that chronic nicotine exposure and withdrawal regulate CRF and melanocortin signaling in the mesocorticolimbic system, possibly contributing to negative affective state and nicotine addiction.
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Affiliation(s)
- Oguz Gozen
- Department of Physiology, School of Medicine, Ege University, 35100 Izmir, Turkey; (O.G.)
- Center for Brain Research, Ege University, 35100 Izmir, Turkey
| | - Buket Aypar
- Department of Physiology, School of Medicine, Ege University, 35100 Izmir, Turkey; (O.G.)
| | - Meliha Ozturk Bintepe
- Department of Physiology, School of Medicine, Ege University, 35100 Izmir, Turkey; (O.G.)
| | - Fulya Tuzcu
- Department of Physiology, School of Medicine, Ege University, 35100 Izmir, Turkey; (O.G.)
| | - Burcu Balkan
- Department of Physiology, School of Medicine, Ege University, 35100 Izmir, Turkey; (O.G.)
- Center for Brain Research, Ege University, 35100 Izmir, Turkey
| | - Ersin O. Koylu
- Department of Physiology, School of Medicine, Ege University, 35100 Izmir, Turkey; (O.G.)
- Center for Brain Research, Ege University, 35100 Izmir, Turkey
| | - Lutfiye Kanit
- Department of Physiology, School of Medicine, Ege University, 35100 Izmir, Turkey; (O.G.)
- Center for Brain Research, Ege University, 35100 Izmir, Turkey
| | - Aysegul Keser
- Department of Physiology, School of Medicine, Ege University, 35100 Izmir, Turkey; (O.G.)
- Center for Brain Research, Ege University, 35100 Izmir, Turkey
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3
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Wei R, Li D, Jia S, Chen Y, Wang J. MC4R in Central and Peripheral Systems. Adv Biol (Weinh) 2023; 7:e2300035. [PMID: 37043700 DOI: 10.1002/adbi.202300035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/25/2023] [Indexed: 04/14/2023]
Abstract
Obesity has emerged as a critical and urgent health burden during the current global pandemic. Among multiple genetic causes, melanocortin receptor-4 (MC4R), involved in food intake and energy metabolism regulation through various signaling pathways, has been reported to be the lead genetic factor in severe and early onset obesity and hyperphagia disorders. Most previous studies have illustrated the roles of MC4R signaling in energy intake versus expenditure in the central system, while some evidence indicates that MC4R is also expressed in peripheral systems, such as the gut and endocrine organs. However, its physiopathological function remains poorly defined. This review aims to depict the central and peripheral roles of MC4R in energy metabolism and endocrine hormone homeostasis, the diversity of phenotypes, biased downstream signaling caused by distinct MC4R mutations, and current drug development targeting the receptor.
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Affiliation(s)
- Ran Wei
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
- Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Shanghai, 200025, China
- Department of Endocrinology, Shanghai Fifth People's Hospital, Fudan University, Shanghai, 200240, China
| | - Danjie Li
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
- Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Shanghai, 200025, China
| | - Sheng Jia
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
- Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Shanghai, 200025, China
| | - Yuhong Chen
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
- Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Shanghai, 200025, China
| | - Jiqiu Wang
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 197 Ruijin 2nd Road, Shanghai, 200025, China
- Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Shanghai, 200025, China
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Markov DD, Dolotov OV, Grivennikov IA. The Melanocortin System: A Promising Target for the Development of New Antidepressant Drugs. Int J Mol Sci 2023; 24:ijms24076664. [PMID: 37047638 PMCID: PMC10094937 DOI: 10.3390/ijms24076664] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/27/2023] [Accepted: 03/30/2023] [Indexed: 04/05/2023] Open
Abstract
Major depression is one of the most prevalent mental disorders, causing significant human suffering and socioeconomic loss. Since conventional antidepressants are not sufficiently effective, there is an urgent need to develop new antidepressant medications. Despite marked advances in the neurobiology of depression, the etiology and pathophysiology of this disease remain poorly understood. Classical and newer hypotheses of depression suggest that an imbalance of brain monoamines, dysregulation of the hypothalamic-pituitary-adrenal axis (HPAA) and immune system, or impaired hippocampal neurogenesis and neurotrophic factors pathways are cause of depression. It is assumed that conventional antidepressants improve these closely related disturbances. The purpose of this review was to discuss the possibility of affecting these disturbances by targeting the melanocortin system, which includes adrenocorticotropic hormone-activated receptors and their peptide ligands (melanocortins). The melanocortin system is involved in the regulation of various processes in the brain and periphery. Melanocortins, including peripherally administered non-corticotropic agonists, regulate HPAA activity, exhibit anti-inflammatory effects, stimulate the levels of neurotrophic factors, and enhance hippocampal neurogenesis and neurotransmission. Therefore, endogenous melanocortins and their analogs are able to complexly affect the functioning of those body’s systems that are closely related to depression and the effects of antidepressants, thereby demonstrating a promising antidepressant potential.
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Affiliation(s)
- Dmitrii D. Markov
- National Research Center “Kurchatov Institute”, Kurchatov Sq. 2, 123182 Moscow, Russia
| | - Oleg V. Dolotov
- National Research Center “Kurchatov Institute”, Kurchatov Sq. 2, 123182 Moscow, Russia
- Faculty of Biology, Lomonosov Moscow State University, Leninskie Gory, 119234 Moscow, Russia
| | - Igor A. Grivennikov
- National Research Center “Kurchatov Institute”, Kurchatov Sq. 2, 123182 Moscow, Russia
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5
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Korgan AC, Oliveira-Abreu K, Wei W, Martin SLA, Bridges ZJD, Leal-Cardoso JH, Kaczorowski CC, O'Connell KMS. High sucrose consumption decouples intrinsic and synaptic excitability of AgRP neurons without altering body weight. Int J Obes (Lond) 2023; 47:224-235. [PMID: 36725979 PMCID: PMC10023568 DOI: 10.1038/s41366-023-01265-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/17/2023] [Accepted: 01/19/2023] [Indexed: 02/03/2023]
Abstract
BACKGROUND/OBJECTIVE As the obesity epidemic continues, the understanding of macronutrient influence on central nervous system function is critical for understanding diet-induced obesity and potential therapeutics, particularly in light of the increased sugar content in processed foods. Previous research showed mixed effects of sucrose feeding on body weight gain but has yet to reveal insight into the impact of sucrose on hypothalamic functioning. Here, we explore the impact of liquid sucrose feeding for 12 weeks on body weight, body composition, caloric intake, and hypothalamic AgRP neuronal function and synaptic plasticity. METHODS Patch-clamp electrophysiology of hypothalamic AgRP neurons, metabolic phenotyping and food intake were performed on C57BL/6J mice. RESULTS While mice given sugar-sweetened water do not gain significant weight, they do show subtle differences in body composition and caloric intake. When given sugar-sweetened water, mice show similar alterations to AgRP neuronal excitability as in high-fat diet obese models. Increased sugar consumption also primes mice for increased caloric intake and weight gain when given access to a HFD. CONCLUSIONS Our results show that elevated sucrose consumption increased activity of AgRP neurons and altered synaptic excitability. This may contribute to obesity in mice and humans with access to more palatable (HFD) diets.
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Affiliation(s)
- Austin C Korgan
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
| | - Klausen Oliveira-Abreu
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brazil
| | - Wei Wei
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
- Georgia State University, Atlanta, GA, USA
| | | | - Zoey J D Bridges
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
| | | | - Catherine C Kaczorowski
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA
- Neuroscience Program, Graduate School of Biomedical Science, Tufts University School of Medicine, Boston, MA, USA
| | - Kristen M S O'Connell
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA.
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA.
- Neuroscience Program, Graduate School of Biomedical Science, Tufts University School of Medicine, Boston, MA, USA.
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6
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Micioni Di Bonaventura E, Botticelli L, Tomassoni D, Tayebati SK, Micioni Di Bonaventura MV, Cifani C. The Melanocortin System behind the Dysfunctional Eating Behaviors. Nutrients 2020; 12:E3502. [PMID: 33202557 PMCID: PMC7696960 DOI: 10.3390/nu12113502] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/09/2020] [Accepted: 11/11/2020] [Indexed: 12/11/2022] Open
Abstract
The dysfunction of melanocortin signaling has been associated with obesity, given the important role in the regulation of energy homeostasis, food intake, satiety and body weight. In the hypothalamus, the melanocortin-3 receptor (MC3R) and melanocortin-4 receptor (MC4R) contribute to the stability of these processes, but MC3R and MC4R are also localized in the mesolimbic dopamine system, the region that responds to the reinforcing properties of highly palatable food (HPF) and where these two receptors seem to affect food reward and motivation. Loss of function of the MC4R, resulting from genetic mutations, leads to overeating in humans, but to date, a clear understanding of the underlying mechanisms and behaviors that promote overconsumption of caloric foods remains unknown. Moreover, the MC4R demonstrated to be a crucial modulator of the stress response, factor that is known to be strictly related to binge eating behavior. In this review, we will explore the preclinical and clinical studies, and the controversies regarding the involvement of melanocortin system in altered eating patterns, especially binge eating behavior, food reward and motivation.
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Affiliation(s)
| | - Luca Botticelli
- School of Pharmacy, University of Camerino, 62032 Camerino, Italy; (E.M.D.B.); (L.B.); (S.K.T.); (C.C.)
| | - Daniele Tomassoni
- School of Bioscience and Veterinary Medicine, University of Camerino, 62032 Camerino, Italy;
| | - Seyed Khosrow Tayebati
- School of Pharmacy, University of Camerino, 62032 Camerino, Italy; (E.M.D.B.); (L.B.); (S.K.T.); (C.C.)
| | | | - Carlo Cifani
- School of Pharmacy, University of Camerino, 62032 Camerino, Italy; (E.M.D.B.); (L.B.); (S.K.T.); (C.C.)
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7
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Dunigan AI, Swanson AM, Olson DP, Roseberry AG. Whole-brain efferent and afferent connectivity of mouse ventral tegmental area melanocortin-3 receptor neurons. J Comp Neurol 2020; 529:1157-1183. [PMID: 32856297 DOI: 10.1002/cne.25013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 07/10/2020] [Accepted: 08/14/2020] [Indexed: 12/27/2022]
Abstract
The mesolimbic dopamine (DA) system is involved in the regulation of multiple behaviors, including feeding, and evidence demonstrates that the melanocortin system can act on the mesolimbic DA system to control feeding and other behaviors. The melanocortin-3 receptor (MC3R) is an important component of the melanocortin system, but its overall role is poorly understood. Because MC3Rs are highly expressed in the ventral tegmental area (VTA) and are likely to be the key interaction point between the melanocortin and mesolimbic DA systems, we set out to identify both the efferent projection patterns of VTA MC3R neurons and the location of the neurons providing afferent input to them. VTA MC3R neurons were broadly connected to neurons across the brain but were strongly connected to a discrete set of brain regions involved in the regulation of feeding, reward, and aversion. Surprisingly, experiments using monosynaptic rabies virus showed that proopiomelanocortin (POMC) and agouti-related protein (AgRP) neurons in the arcuate nucleus made few direct synapses onto VTA MC3R neurons or any of the other major neuronal subtypes in the VTA, despite being extensively labeled by general retrograde tracers injected into the VTA. These results greatly contribute to our understanding of the anatomical interactions between the melanocortin and mesolimbic systems and provide a foundation for future studies of VTA MC3R neurons and the circuits containing them in the control of feeding and other behaviors.
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Affiliation(s)
- Anna I Dunigan
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | - Andrew M Swanson
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| | - David P Olson
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
| | - Aaron G Roseberry
- Department of Biology, Georgia State University, Atlanta, Georgia, USA.,Neuroscience Institute, Georgia State University, Atlanta, Georgia, USA
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8
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Qu N, He Y, Wang C, Xu P, Yang Y, Cai X, Liu H, Yu K, Pei Z, Hyseni I, Sun Z, Fukuda M, Li Y, Tian Q, Xu Y. A POMC-originated circuit regulates stress-induced hypophagia, depression, and anhedonia. Mol Psychiatry 2020; 25:1006-1021. [PMID: 31485012 PMCID: PMC7056580 DOI: 10.1038/s41380-019-0506-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 06/01/2019] [Accepted: 07/17/2019] [Indexed: 01/27/2023]
Abstract
Chronic stress causes dysregulations of mood and energy homeostasis, but the neurocircuitry underlying these alterations remain to be fully elucidated. Here we demonstrate that chronic restraint stress in mice results in hyperactivity of pro-opiomelanocortin neurons in the arcuate nucleus of the hypothalamus (POMCARH neurons) associated with decreased neural activities of dopamine neurons in the ventral tegmental area (DAVTA neurons). We further revealed that POMCARH neurons project to the VTA and provide an inhibitory tone to DAVTA neurons via both direct and indirect neurotransmissions. Finally, we show that photoinhibition of the POMCARH→VTA circuit in mice increases body weight and food intake, and reduces depression-like behaviors and anhedonia in mice exposed to chronic restraint stress. Thus, our results identified a novel neurocircuitry regulating feeding and mood in response to stress.
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Affiliation(s)
- Na Qu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
- Affiliated Wuhan Mental Health Center, Tongji Medical College, Huazhong University of Science and Technology, 430012, Wuhan, China
| | - Yanlin He
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Chunmei Wang
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Pingwen Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Yongjie Yang
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Xing Cai
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Hesong Liu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Kaifan Yu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Zhou Pei
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Ilirjana Hyseni
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Zheng Sun
- Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Makoto Fukuda
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Yi Li
- Affiliated Wuhan Mental Health Center, Tongji Medical College, Huazhong University of Science and Technology, 430012, Wuhan, China
- Research Center for Psychological and Health Sciences, China University of Geosciences, 430074, Wuhan, China
| | - Qing Tian
- Department of Pathology and Pathophysiology, School of Basic Medicine, Institute for Brain Research, Huazhong University of Science and Technology, 430030, Wuhan, China
| | - Yong Xu
- Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
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9
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Liu S, Guo R, Liu F, Yuan Q, Yu Y, Ren F. Gut Microbiota Regulates Depression-Like Behavior in Rats Through the Neuroendocrine-Immune-Mitochondrial Pathway. Neuropsychiatr Dis Treat 2020; 16:859-869. [PMID: 32280227 PMCID: PMC7127849 DOI: 10.2147/ndt.s243551] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/01/2020] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Gut microbiota affects various physiological functions in the host and has crucial effects on the nervous system. There is increasing evidence of a correlation between gut microbiota and depression; however, the mechanisms underlying the regulation of depression-like behavior by gut microbiota remain unclear. In this study, we assessed the regulatory mechanism of gut microbiota on depression-like behavior in rats. METHODS We transplanted fecal microbiota obtained from patients with depression and healthy individuals into germ-free (GF) rats (n=18) through fecal microbiota transplantation technology. Next, we assessed the affective behavior in the rats using the forced swimming test and a sucrose preference test. We used enzyme-linked immunosorbent assay (ELISA) to determine the hippocampal levels of 5-hydroxytryptamine (5-HT), dopamine (DA), and noradrenaline (NE) and the serum levels of corticosterone (CORT), adrenocorticotropic hormone (ACTH), corticotropin-releasing hormone (CRH), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-6 (IL-6), interleukin-1 (IL-1), interleukin-1 (IL-4), and interleukin-1 (IL-10). The mitochondrial morphology of small intestinal epithelial cells was observed through transmission electron microscopy. RESULTS Rats that received fecal microbiota from patients with depression (depression microbiota) exhibited depression-like behavior. They presented decreased levels of hippocampal neurotransmitters, serum CORT levels, and anti-inflammatory cytokine levels, as well as increased ACTH, CRH, and serum levels of multiple pro-inflammatory cytokines. Observation of the mitochondria ultrastructure showed damaged mitochondria in the intestinal epithelial cells, significant endoplasmic reticulum expansion, and border aggregation of nuclear chromatin. CONCLUSION Our findings suggested that the depression-like behaviors induced by the depression microbiota through the neuroendocrine-immune-mitochondrial pathway, which were associated with neuroendocrine disorders, inflammatory responses, and mitochondrial damage.
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Affiliation(s)
- Shuhan Liu
- Second Clinical Medical College, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China
| | - Rongjuan Guo
- Department of Neurology, Dongfang Hospital Beijing University of Chinese Medicine, Beijing 100078, People's Republic of China
| | - Fei Liu
- College of Acupuncture and Massage, Changchun University of Chinese Medicine, Changchun 130117, People's Republic of China
| | - Qingjie Yuan
- Department of Traditional Chinese Medicine, Tsinghua University Yuquan Hospital, Beijing 100040, People's Republic of China
| | - Yao Yu
- Second Clinical Medical College, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China
| | - Feifei Ren
- Second Clinical Medical College, Beijing University of Chinese Medicine, Beijing 100029, People's Republic of China
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10
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West KS, Lu C, Olson DP, Roseberry AG. Alpha-melanocyte stimulating hormone increases the activity of melanocortin-3 receptor-expressing neurons in the ventral tegmental area. J Physiol 2019; 597:3217-3232. [PMID: 31054267 DOI: 10.1113/jp277193] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 04/19/2019] [Indexed: 01/12/2023] Open
Abstract
KEY POINTS Alpha-melanocyte stimulating hormone (α-MSH) is an anorexigenic peptide. Injection of the α-MSH analog MTII into the ventral tegmental area (VTA) decreases food and sucrose intake and food reward. Melanocortin-3 receptors (MC3R) are highly expressed in the VTA, suggesting that the effects of intra-VTA α-MSH may be mediated by α-MSH changing the activity of MC3R-expressing VTA neurons. α-MSH increased the firing rate of MC3R VTA neurons in acute brain slices from mice, although it did not affect the firing rate of non-MC3R VTA neurons. The α-MSH induced increase in MC3R neuron firing rate is probably activity-dependent, and was independent of fast synaptic transmission and intracellular Ca2+ levels. These results help us to better understand how α-MSH acts in the VTA to affect feeding and other dopamine-dependent behaviours. ABSTRACT The mesocorticolimbic dopamine system, the brain's reward system, regulates multiple behaviours, including food intake and food reward. There is substantial evidence that the melanocortin system of the hypothalamus, an important neural circuit controlling feeding and body weight, interacts with the mesocorticolimbic dopamine system to affect feeding, food reward and body weight. For example, melanocortin-3 receptors (MC3Rs) are expressed in the ventral tegmental area (VTA) and our laboratory previously showed that intra-VTA injection of the MC3R agonist, MTII, decreases home-cage food intake and operant responding for sucrose pellets. However, the cellular mechanisms underlying the effects of intra-VTA alpha-melanocyte stimulating hormone (α-MSH) on feeding and food reward are unknown. To determine how α-MSH acts in the VTA to affect feeding, we performed electrophysiological recordings in acute brain slices from mice expressing enhanced yellow fluorescent protein in MC3R neurons to test how α-MSH affects the activity of VTA MC3R neurons. α-MSH significantly increased the firing rate of VTA MC3R neurons without altering the activity of non-MC3R expressing VTA neurons. In addition, the α-MSH-induced increase in MC3R neuron activity was independent of fast synaptic transmission and intracellular Ca2+ levels. Finally, we show that the effect of α-MSH on MC3R neuron firing rate is probably activity-dependent. Overall, these studies provide an important advancement in the understanding of how α-MSH acts in the VTA to affect feeding and food reward.
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Affiliation(s)
| | - Chunxia Lu
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - David P Olson
- Department of Pediatrics, University of Michigan, Ann Arbor, MI, USA
| | - Aaron G Roseberry
- Department of Biology.,Neuroscience Institute, , Georgia State University, Atlanta, GA, USA
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Baldini G, Phelan KD. The melanocortin pathway and control of appetite-progress and therapeutic implications. J Endocrinol 2019; 241:R1-R33. [PMID: 30812013 PMCID: PMC6500576 DOI: 10.1530/joe-18-0596] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 01/22/2019] [Indexed: 12/19/2022]
Abstract
The initial discovery that ob/ob mice become obese because of a recessive mutation of the leptin gene has been crucial to discover the melanocortin pathway to control appetite. In the melanocortin pathway, the fed state is signaled by abundance of circulating hormones such as leptin and insulin, which bind to receptors expressed at the surface of pro-opiomelanocortin (POMC) neurons to promote processing of POMC to the mature hormone α-melanocyte-stimulating hormone (α-MSH). The α-MSH released by POMC neurons then signals to decrease energy intake by binding to melanocortin-4 receptor (MC4R) expressed by MC4R neurons to the paraventricular nucleus (PVN). Conversely, in the 'starved state' activity of agouti-related neuropeptide (AgRP) and of neuropeptide Y (NPY)-expressing neurons is increased by decreased levels of circulating leptin and insulin and by the orexigenic hormone ghrelin to promote food intake. This initial understanding of the melanocortin pathway has recently been implemented by the description of the complex neuronal circuit that controls the activity of POMC, AgRP/NPY and MC4R neurons and downstream signaling by these neurons. This review summarizes the progress done on the melanocortin pathway and describes how obesity alters this pathway to disrupt energy homeostasis. We also describe progress on how leptin and insulin receptors signal in POMC neurons, how MC4R signals and how altered expression and traffic of MC4R change the acute signaling and desensitization properties of the receptor. We also describe how the discovery of the melanocortin pathway has led to the use of melanocortin agonists to treat obesity derived from genetic disorders.
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Affiliation(s)
- Giulia Baldini
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Kevin D. Phelan
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Altered sucrose self-administration following injection of melanocortin receptor agonists and antagonists into the ventral tegmental area. Psychopharmacology (Berl) 2017; 234:1683-1692. [PMID: 28243712 DOI: 10.1007/s00213-017-4570-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 02/10/2017] [Indexed: 12/26/2022]
Abstract
RATIONALE AND OBJECTIVES Alpha-melanocyte stimulating hormone (αMSH) and agouti-related protein (AgRP) are antagonistic neuropeptides that play an important role in the control of feeding and body weight through their central actions on the melanocortin-3 and melanocortin-4 receptors. Increasing evidence indicates that αMSH and AgRP can interact with the mesolimbic dopamine system to regulate feeding as well as other behaviors. For example, we have shown previously that injection of melanocortin receptor agonists and antagonists into the ventral tegmental area (VTA) alters both normal home-cage feeding and the intake of sucrose solutions, but it remains unknown whether αMSH and AgRP can also act in the VTA to affect reward-related feeding. METHODS We tested whether injection of the melanocortin receptor agonist, MTII, or the melanocortin receptor antagonist, SHU9119, directly into the VTA affected operant responding maintained by sucrose pellets in self-administration assays. RESULTS Injection of MTII into the VTA decreased operant responding maintained by sucrose pellets on both fixed ratio and progressive ratio schedules of reinforcement, whereas SHU9119 increased operant responding under fixed ratio, but not progressive ratio schedules. MTII also increased and SHU9119 decreased 24-h home-cage food intake. CONCLUSIONS This study demonstrates that αMSH and AgRP act in the VTA to affect sucrose self-administration. Thus, it adds critical information to the growing literature showing that in addition to their well-characterized role in controlling "need-based" feeding, αMSH and AgRP can also act on the mesolimbic dopamine system to control reward-related behavior.
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Tapinc DE, Ilgin R, Kaya E, Gozen O, Ugur M, Koylu EO, Kanit L, Keser A, Balkan B. Gene expression of pro-opiomelanocortin and melanocortin receptors is regulated in the hypothalamus and mesocorticolimbic system following nicotine administration. Neurosci Lett 2017; 637:75-79. [DOI: 10.1016/j.neulet.2016.11.049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 12/17/2022]
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Abstract
Many of the neurocircuits and hormones known to underlie the sensations of hunger and satiety also substantially alter the activity of the dopaminergic reward system. Much interest lies in the ways that hunger, satiety, and reward tie together, as the epidemic of obesity seems tied to the recent development and mass availability of highly palatable foods. In this review, we will first discuss the basic neurocircuitry of the midbrain and basal forebrain reward system. We will elaborate how several important mediators of hunger-the agouti-related protein neurons of the arcuate nucleus, the lateral hypothalamic nucleus, and ghrelin-enhance the sensitivity of the dopaminergic reward system. Then, we will elaborate how mediators of satiety-the nucleus tractus solitarius, pro-opiomelanocortin neurons of the arcuate nucleus, and its peripheral hormonal influences such as leptin-reduce the reward system sensitivity. We hope to provide a template by which future research may identify the ways in which highly rewarding foods bypass this balanced system to produce excessive food consumption.
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Affiliation(s)
- Ryan Michael Cassidy
- Brown Foundation of the Institute of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, Neuroscience Program MD Anderson Cancer Center and UTHealth Graduate School of Biological Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA
- *Correspondence: Ryan Michael Cassidy,
| | - Qingchun Tong
- Brown Foundation of the Institute of Molecular Medicine for the Prevention of Human Diseases of McGovern Medical School, Neuroscience Program MD Anderson Cancer Center and UTHealth Graduate School of Biological Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA
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Devarakonda K, Mobbs CV. Mechanisms and significance of brain glucose signaling in energy balance, glucose homeostasis, and food-induced reward. Mol Cell Endocrinol 2016; 438:61-69. [PMID: 27637346 DOI: 10.1016/j.mce.2016.09.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 09/12/2016] [Accepted: 09/12/2016] [Indexed: 12/15/2022]
Abstract
The concept that hypothalamic glucose signaling plays an important role in regulating energy balance, e.g., as instantiated in the so-called "glucostat" hypothesis, is one of the oldest in the field of metabolism. However the mechanisms by which neurons in the hypothalamus sense glucose, and the function of glucose signaling in the brain, has been difficult to establish. Nevertheless recent studies probing mechanisms of glucose signaling have also strongly supported a role for glucose signaling in regulating energy balance, glucose homeostasis, and food-induced reward.
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Affiliation(s)
- Kavya Devarakonda
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave., 9-119, New York, NY 10029, USA; Department of Endocrinology, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave., 9-119, New York, NY 10029, USA
| | - Charles V Mobbs
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave., 9-119, New York, NY 10029, USA; Department of Endocrinology, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave., 9-119, New York, NY 10029, USA; Department of Geriatrics, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave., 9-119, New York, NY 10029, USA.
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Murray S, Tulloch A, Criscitelli K, Avena NM. Recent studies of the effects of sugars on brain systems involved in energy balance and reward: Relevance to low calorie sweeteners. Physiol Behav 2016; 164:504-508. [PMID: 27068180 PMCID: PMC5003688 DOI: 10.1016/j.physbeh.2016.04.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 04/02/2016] [Accepted: 04/04/2016] [Indexed: 12/29/2022]
Abstract
The alarmingly high rates of overweight and obesity pose a serious global health threat. Numerous factors can result in weight gain, one of which is excess consumption of caloric sweeteners. In an effort to aid weight loss efforts, many people have switched from caloric sweeteners to low calorie sweeteners, which provide sweet taste without the accompanying calories. In this review, we present an overview of the animal literature produced in the last 5years highlighting the effects of sugar consumption on neural pathways involved in energy balance regulation and reward processing. We also examine the latest evidence that is beginning to elucidate the effects of low calorie sweeteners on these neural pathways, as well as how homeostatic and hedonic systems interact in response to, or to influence, sugar consumption.
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Affiliation(s)
- Susan Murray
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY 10025, United States
| | - Alastair Tulloch
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY 10025, United States
| | - Kristen Criscitelli
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY 10025, United States
| | - Nicole M Avena
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY 10025, United States
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MCH receptor deletion does not impair glucose-conditioned flavor preferences in mice. Physiol Behav 2016; 163:239-244. [PMID: 27195455 DOI: 10.1016/j.physbeh.2016.05.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 04/06/2016] [Accepted: 05/14/2016] [Indexed: 11/22/2022]
Abstract
The post-oral actions of glucose stimulate intake and condition flavor preferences in rodents. Hypothalamic melanin-concentrating hormone (MCH) neurons are implicated in sugar reward, and this study investigated their involvement in glucose preference conditioning in mice. In Exp. 1 MCH receptor 1 knockout (KO) and C57BL/6 wildtype (WT) mice learned to prefer 8% glucose over an initially more-preferred non-nutritive 0.1% sucralose+saccharin (S+S) solution. In contrast, the KO and WT mice preferred S+S to 8% fructose, which is consistent with this sugar's weak post-oral reinforcing action. In Exp. 2 KO and WT mice were trained to drink a flavored solution (CS+) paired with intragastric (IG) infusion of 16% glucose and a different flavored solution (CS-) paired with IG water. Both groups drank more CS+ than CS- in training and preferred the CS+ to CS- in a 2-bottle test. These results indicate that MCH receptor signaling is not required for flavor preferences conditioned by the post-oral actions of glucose. This contrasts with other findings implicating MCH signaling in other types of sugar reward processing.
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Hoffman KL. New dimensions in the use of rodent behavioral tests for novel drug discovery and development. Expert Opin Drug Discov 2016; 11:343-53. [DOI: 10.1517/17460441.2016.1153624] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Ghrelin receptor (GHS-R1A) antagonism alters preference for ethanol and sucrose in a concentration-dependent manner in prairie voles. Physiol Behav 2016; 155:231-6. [DOI: 10.1016/j.physbeh.2015.12.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 12/14/2015] [Accepted: 12/15/2015] [Indexed: 02/02/2023]
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Interacting Neural Processes of Feeding, Hyperactivity, Stress, Reward, and the Utility of the Activity-Based Anorexia Model of Anorexia Nervosa. Harv Rev Psychiatry 2016; 24:416-436. [PMID: 27824637 PMCID: PMC5485261 DOI: 10.1097/hrp.0000000000000111] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Anorexia nervosa (AN) is a psychiatric illness with minimal effective treatments and a very high rate of mortality. Understanding the neurobiological underpinnings of the disease is imperative for improving outcomes and can be aided by the study of animal models. The activity-based anorexia rodent model (ABA) is the current best parallel for the study of AN. This review describes the basic neurobiology of feeding and hyperactivity seen in both ABA and AN, and compiles the research on the role that stress-response and reward pathways play in modulating the homeostatic drive to eat and to expend energy, which become dysfunctional in ABA and AN.
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Roseberry AG, Stuhrman K, Dunigan AI. Regulation of the mesocorticolimbic and mesostriatal dopamine systems by α-melanocyte stimulating hormone and agouti-related protein. Neurosci Biobehav Rev 2015; 56:15-25. [DOI: 10.1016/j.neubiorev.2015.06.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 06/15/2015] [Accepted: 06/21/2015] [Indexed: 11/24/2022]
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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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Dopamine release in the lateral hypothalamus is stimulated by α-MSH in both the anticipatory and consummatory phases of feeding. Psychoneuroendocrinology 2015; 56:79-87. [PMID: 25805178 DOI: 10.1016/j.psyneuen.2015.02.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 02/24/2015] [Accepted: 02/24/2015] [Indexed: 12/14/2022]
Abstract
α-Melanocyte-stimulating hormone (α-MSH), is a hypothalamic neuropeptide signaling satiation, but it is not known if α-MSH may stimulate dopamine release in a feeding control brain region of the lateral hypothalamic area (LHA), during the anticipatory and consummatory phases of feeding behavior. To address these questions, dynamics of dopamine release were measured in 15 min microdialysis samples simultaneously from the LHA and the nucleus accumbens (NAc) during consecutive exposure and provision of food and 1% sucrose in Wistar rats after overnight food deprivation. α-MSH was infused via the microdialysis probe either into the LHA or NAc starting before food exposure. Food, sucrose and water intakes were automatically monitored and analyzed concomitantly with microdialysis samples. We found that LHA-α-MSH-infused rats stopped eating earlier and consumed less food and sucrose as compared to control and NAc-α-MSH-infused rats. Exposure to food produced a peak of LHA dopamine in both LHA-α-MSH and NAc-α-MSH-infused rats but not in the controls. During food provision, LHA dopamine levels were strongly elevated in LHA-α-MSH infused rats, while delivery of α-MSH into the NAc induced a less intense increase of dopamine in both NAc and LHA. In all rats, LHA dopamine levels correlated inversely with sucrose intake. In conclusion, our study showed that α-MSH stimulates dopamine release in the LHA during both the anticipatory and consummatory phases of feeding, decreases food intake and inhibits sucrose intake. These data suggest that LHA dopamine release can be involved in α-MSH anorexigenic effects.
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