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Hou G, Hao M, Duan J, Han MH. The Formation and Function of the VTA Dopamine System. Int J Mol Sci 2024; 25:3875. [PMID: 38612683 PMCID: PMC11011984 DOI: 10.3390/ijms25073875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 03/12/2024] [Accepted: 03/14/2024] [Indexed: 04/14/2024] Open
Abstract
The midbrain dopamine system is a sophisticated hub that integrates diverse inputs to control multiple physiological functions, including locomotion, motivation, cognition, reward, as well as maternal and reproductive behaviors. Dopamine is a neurotransmitter that binds to G-protein-coupled receptors. Dopamine also works together with other neurotransmitters and various neuropeptides to maintain the balance of synaptic functions. The dysfunction of the dopamine system leads to several conditions, including Parkinson's disease, Huntington's disease, major depression, schizophrenia, and drug addiction. The ventral tegmental area (VTA) has been identified as an important relay nucleus that modulates homeostatic plasticity in the midbrain dopamine system. Due to the complexity of synaptic transmissions and input-output connections in the VTA, the structure and function of this crucial brain region are still not fully understood. In this review article, we mainly focus on the cell types, neurotransmitters, neuropeptides, ion channels, receptors, and neural circuits of the VTA dopamine system, with the hope of obtaining new insight into the formation and function of this vital brain region.
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Affiliation(s)
- Guoqiang Hou
- Faculty of Life and Health Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China (M.H.); (J.D.)
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Mei Hao
- Faculty of Life and Health Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China (M.H.); (J.D.)
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Jiawen Duan
- Faculty of Life and Health Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China (M.H.); (J.D.)
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Ming-Hu Han
- Faculty of Life and Health Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China (M.H.); (J.D.)
- Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
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2
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Fam J, Holmes N, Westbrook RF. Stimulating oxytocin receptors in the basolateral amygdala enhances stimulus processing: Differential and consistent effects for stimuli paired with fear versus sucrose in extinction and reversal learning. Psychoneuroendocrinology 2024; 160:106917. [PMID: 38071877 DOI: 10.1016/j.psyneuen.2023.106917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/24/2023] [Accepted: 11/28/2023] [Indexed: 01/02/2024]
Abstract
Oxytocin (OT) influences a range of social behaviors by enhancing the salience of social cues and regulating the expression of specific social behaviors (e.g., maternal care versus defensive aggression). We previously showed that stimulating OT receptors in the basolateral amygdala of rats also enhanced the salience of fear conditioned stimuli: relative to rats given vehicle infusions, rats infused with [Thr4,Gly7]-oxytocin (TGOT), a selective OT receptor agonist, showed greater discrimination between a cue predictive of danger, and one that signaled safety. In the present series of experiments using male rats, the effects of OT receptor activation in the basolateral amygdala on stimulus processing were examined further using conditioning protocols that consist of changes in stimulus-outcome contingencies (i.e., extinction and reversal), and with stimuli paired with aversive (i.e., foot shock) and appetitive (i.e., sucrose) outcomes. It was revealed that the effects of OTR stimulation diverge for aversive and appetitive learning - enhancing the former but not the latter. However, across both types of learning, OTR stimulation enhanced the detection of conditioned stimuli. Overall, these results are consistent with an emerging view of OT's effects on stimulus salience; facilitating the detection of meaningful stimuli while reducing responding to those that are irrelevant.
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Affiliation(s)
- Justine Fam
- School of Psychology, University of New South Wales, Australia.
| | - Nathan Holmes
- School of Psychology, University of New South Wales, Australia
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3
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Zhan S, Qi Z, Cai F, Gao Z, Xie J, Hu J. Oxytocin neurons mediate stress-induced social memory impairment. Curr Biol 2024; 34:36-45.e4. [PMID: 38103551 DOI: 10.1016/j.cub.2023.11.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 10/27/2023] [Accepted: 11/17/2023] [Indexed: 12/19/2023]
Abstract
Oxytocin has long been thought to play a substantial role in social behaviors, such as social attachment and parenting behavior. However, how oxytocin neurons respond to social and non-social stimuli is largely unknown, especially in high temporal resolution. Here, we recorded the in vivo real-time responses of oxytocin neurons in the paraventricular nucleus of the hypothalamus (PVN) in freely behaving mice. Our results revealed that oxytocin neurons were activated more significantly by stressors than social stimuli. The activation of oxytocin neurons was precisely correlated with struggling behavior during stress. Furthermore, we found that oxytocin mediated stress-induced social memory impairment. Our results reveal an important role of PVN oxytocin neurons in stress-induced social amnesia.
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Affiliation(s)
- Shulu Zhan
- School of Life Science and Technology, ShanghaiTech University, 393 Huaxia Middle Road, Shanghai 201210, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China; Institute of Neuroscience, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhenhua Qi
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou 510060, China
| | - Fang Cai
- School of Life Science and Technology, ShanghaiTech University, 393 Huaxia Middle Road, Shanghai 201210, China
| | - Zilong Gao
- Chinese Institute for Brain Research, Beijing (CIBR), Bldg. 3, No. 9, YIKE Rd, Zhongguancun Life Science Park, Changping District, Beijing 102206, China.
| | - Jingdun Xie
- Department of Anesthesiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, 651 Dongfeng East Road, Guangzhou 510060, China.
| | - Ji Hu
- School of Life Science and Technology, ShanghaiTech University, 393 Huaxia Middle Road, Shanghai 201210, China; Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China.
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4
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Liyanagamage DSNK, McColl LK, Glasgow LNM, Levine AS, Olszewski PK. Effect of intranasal oxytocin on palatable food consumption and c-Fos immunoreactivity in relevant brain areas in rats. Physiol Behav 2023; 271:114318. [PMID: 37543105 DOI: 10.1016/j.physbeh.2023.114318] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 08/01/2023] [Accepted: 08/02/2023] [Indexed: 08/07/2023]
Abstract
Peripheral and central injections of oxytocin (OT) in laboratory animals decrease eating for energy and palatability, but the hypophagic response is dependent on the administration route. Human studies rely on intranasal (IN) administration of the peptide, the route underutilized in OT animal feeding studies thus far. Therefore, we examined the effect of IN OT on various aspects of food consumption in rats: (a) overnight deprivation-induced standard chow intake, (b) episodic (2-h) consumption of calorie-dense and palatable high-fat high-sugar (HFHS) chow, (c) 2-h episodic intake of palatable and calorie-dilute sucrose and Intralipid solutions, and (d) 2-h sucrose solution intake in rats habituated to ingesting this solution daily for several weeks. Finally, we assessed c-Fos changes in response to the acute IN OT administration in rats habituated to daily sugar consumption. We found that IN 20μg OT decreased deprivation-induced intake of standard chow and HFHS chow in nondeprived rats without affecting water consumption. IN OT also reduced 2-hour episodic fluid consumption of sucrose, but not Intralipid. In the habitual sugar consumption paradigm, acute IN OT diminished sucrose solution intake in animals accustomed to the 2-hour/day sucrose meal regimen. In rats habitually consuming sucrose, IN OT altered c-Fos immunoreactivity in brain areas related to energy homeostasis and reward, including the central nucleus of the amygdala, the hypothalamic paraventricular and the arcuate nuclei. We conclude that IN OT is an effective appetite suppressant for carbohydrate/sugar diets in rats and its effects involve feeding-related brain circuits.
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Affiliation(s)
| | - Laura K McColl
- Faculty of Science and Engineering, University of Waikato, Hamilton 3240, New Zealand
| | - Lisa N M Glasgow
- Faculty of Science and Engineering, University of Waikato, Hamilton 3240, New Zealand
| | - Allen S Levine
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108, United States of America
| | - Pawel K Olszewski
- Faculty of Science and Engineering, University of Waikato, Hamilton 3240, New Zealand; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108, United States of America; Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN 55414, United States of America.
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5
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Cuesta-Marti C, Uhlig F, Muguerza B, Hyland N, Clarke G, Schellekens H. Microbes, oxytocin and stress: Converging players regulating eating behavior. J Neuroendocrinol 2023; 35:e13243. [PMID: 36872624 DOI: 10.1111/jne.13243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/26/2023] [Accepted: 02/02/2023] [Indexed: 02/17/2023]
Abstract
Oxytocin is a peptide-hormone extensively studied for its multifaceted biological functions and has recently gained attention for its role in eating behavior, through its action as an anorexigenic neuropeptide. Moreover, the gut microbiota is involved in oxytocinergic signaling through the brain-gut axis, specifically in the regulation of social behavior. The gut microbiota is also implicated in appetite regulation and is postulated to play a role in central regulation of hedonic eating. In this review, we provide an overview on oxytocin and its individual links with the microbiome, the homeostatic and non-homeostatic regulation of eating behavior as well as social behavior and stress.
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Affiliation(s)
- Cristina Cuesta-Marti
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland
- APC Microbiome Ireland, Cork, Ireland
| | - Friederike Uhlig
- APC Microbiome Ireland, Cork, Ireland
- Department of Physiology, University College Cork, Ireland
| | - Begoña Muguerza
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland
- APC Microbiome Ireland, Cork, Ireland
- Universitat Rovira i Virgili, Department of Biochemistry & Biotechnology, Nutrigenomics Research Group, Tarragona, Spain
| | - Niall Hyland
- APC Microbiome Ireland, Cork, Ireland
- Department of Physiology, University College Cork, Ireland
| | - Gerard Clarke
- APC Microbiome Ireland, Cork, Ireland
- Department of Psychiatry & Neurobehavioural Science, University College Cork, Cork, Ireland
| | - Harriët Schellekens
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland
- APC Microbiome Ireland, Cork, Ireland
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6
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Jing P, Shan Q. Exogenous oxytocin microinjection into the nucleus accumbens shell attenuates social dominance in group-housed male mice. Physiol Behav 2023:114253. [PMID: 37270150 DOI: 10.1016/j.physbeh.2023.114253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/29/2023] [Accepted: 05/31/2023] [Indexed: 06/05/2023]
Abstract
The nucleus accumbens (NAc), a part of the brain's limbic system, is involved in a variety of brain functions, including reward motivation and social hierarchy. Here, the study investigated the effect of intra-NAc different subregions microinjections of oxytocin on social hierarchy regulation. The hierarchical ranking of group-housed male mice in laboratory settings was determined through the tube test, and a new reliable and robust behavior assay-the mate competition test-was proposed. The mice were randomly divided into two groups, and the bilateral guide cannula was implanted into the shell and core of the NAc, respectively. After social dominance stabilized, changes in social hierarchy were determined through the tube test, warm spot, and mate competition tests. Intra-NAc shell microinjections of oxytocin (0.5 μg/site), but not the core (0.5 μg/site), significantly reduced the social dominance of mice. In addition, oxytocin microinjection into both the shell and core of the NAc significantly increased locomotor ability without affecting anxious behaviors. These findings are tremendously important in understanding the functions of the NAc subregions for social dominance and are more likely to indicate the potential of an oxytocin therapeutic strategy for psychiatric disorders and social impairments.
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Affiliation(s)
- Pengbo Jing
- Laboratory for Synaptic Plasticity, Shantou University Medical College, Shantou, Guangdong, 515041, China
| | - Qiang Shan
- Laboratory for Synaptic Plasticity, Shantou University Medical College, Shantou, Guangdong, 515041, China.
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Hassan S, El Baradey H, Madi M, Shebl M, Leng G, Lozic M, Ludwig M, Menzies J, MacGregor D. Measuring oxytocin release in response to gavage: Computational modelling and assay validation. J Neuroendocrinol 2023; 35:e13303. [PMID: 37316906 PMCID: PMC10909523 DOI: 10.1111/jne.13303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 04/18/2023] [Accepted: 04/28/2023] [Indexed: 06/16/2023]
Abstract
In the present experiments, we tested the conclusion from previous electrophysiological experiments that gavage of sweet food and systemically applied insulin both stimulate oxytocin secretion. To do so, we measured oxytocin secretion from urethane-anaesthetised male rats, and demonstrated a significant increase in secretion in response to gavage of sweetened condensed milk but not isocaloric cream, and a significant increase in response to intravenous injection of insulin. We compared the measurements made in response to sweetened condensed milk with the predictions from a computational model, which we used to predict plasma concentrations of oxytocin from the published electrophysiological responses of oxytocin cells. The prediction from the computational model was very closely aligned to the levels of oxytocin measured in rats in response to gavage.
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Affiliation(s)
- Shereen Hassan
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Department of Medical Physiology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Hala El Baradey
- Department of Medical Physiology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Mohamed Madi
- Department of Medical Physiology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Mohamed Shebl
- Department of Medical Physiology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Gareth Leng
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Maja Lozic
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Mike Ludwig
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Centre for Neuroendocrinology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
| | - John Menzies
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Duncan MacGregor
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
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Wronski ML, Plessow F, Kerem L, Asanza E, O'Donoghue ML, Stanford FC, Bredella MA, Torriani M, Soukas AA, Kheterpal A, Eddy KT, Holmes TM, Deckersbach T, Vangel M, Holsen LM, Lawson EA. A randomized, double-blind, placebo-controlled clinical trial of 8-week intranasal oxytocin administration in adults with obesity: Rationale, study design, and methods. Contemp Clin Trials 2022; 122:106909. [PMID: 36087842 PMCID: PMC10329413 DOI: 10.1016/j.cct.2022.106909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/28/2022] [Accepted: 09/02/2022] [Indexed: 01/27/2023]
Abstract
BACKGROUND Obesity affects more than one-third of adults in the U.S., and effective treatment options are urgently needed. Oxytocin administration induces weight loss in animal models of obesity via effects on caloric intake, energy expenditure, and fat metabolism. We study intranasal oxytocin, an investigational drug shown to reduce caloric intake in humans, as a potential novel treatment for obesity. METHODS We report the rationale, design, methods, and biostatistical analysis plan of a randomized, double-blind, placebo-controlled clinical trial of intranasal oxytocin for weight loss (primary endpoint) in adults with obesity. Participants (aged 18-45 years) were randomly allocated (1:1) to oxytocin (four times daily over eight weeks) versus placebo. Randomization was stratified by biological sex and BMI (30 to <35, 35 to <40, ≥40 kg/m2). We investigate the efficacy, safety, and mechanisms of oxytocin administration in reducing body weight. Secondary endpoints include changes in resting energy expenditure, body composition, caloric intake, metabolic profile, and brain activation via functional magnetic resonance imaging in response to food images and during an impulse control task. Safety and tolerability (e.g., review of adverse events, vital signs, electrocardiogram, comprehensive metabolic panel) are assessed throughout the study and six weeks after treatment completion. RESULTS Sixty-one male and female participants aged 18-45 years were randomized (mean age 34 years, mean BMI 37 kg/m2). The study sample is diverse with 38% identifying as non-White and 20% Hispanic. CONCLUSION Investigating intranasal oxytocin's efficacy, safety, and mechanisms as an anti-obesity medication will advance the search for optimal treatment strategies for obesity and its associated severe sequelae.
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Affiliation(s)
- Marie-Louis Wronski
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Translational Developmental Neuroscience Section, Division of Psychological and Social Medicine and Developmental Neurosciences, Faculty of Medicine, TU Dresden, Dresden, Germany
| | - Franziska Plessow
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Liya Kerem
- Division of Pediatric Endocrinology, Department of Pediatrics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Elisa Asanza
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Michelle L O'Donoghue
- TIMI Study Group, Division of Cardiovascular Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Fatima C Stanford
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Division of Pediatric Endocrinology, Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Miriam A Bredella
- Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Martin Torriani
- Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Alexander A Soukas
- Center for Genomic Medicine, Diabetes Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Arvin Kheterpal
- Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Kamryn T Eddy
- Eating Disorders Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Tara M Holmes
- Translational and Clinical Research Centers, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Thilo Deckersbach
- Diploma Hochschule/University of Applied Sciences, Bad Sooden-Allendorf, Germany
| | - Mark Vangel
- Biostatistics Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Laura M Holsen
- Division of Women's Health, Department of Medicine and Department of Psychiatry, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Elizabeth A Lawson
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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Olszewski PK, Noble EE, Paiva L, Ueta Y, Blevins JE. Oxytocin as a potential pharmacological tool to combat obesity. J Neuroendocrinol 2022; 34:e13106. [PMID: 35192207 PMCID: PMC9372234 DOI: 10.1111/jne.13106] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 02/06/2022] [Accepted: 02/08/2022] [Indexed: 11/30/2022]
Abstract
The neuropeptide oxytocin (OT) has emerged as an important anorexigen in the regulation of food intake and energy balance. It has been shown that the release of OT and activation of hypothalamic OT neurons coincide with food ingestion. Its effects on feeding have largely been attributed to limiting meal size through interactions in key regulatory brain regions governing the homeostatic control of food intake such as the hypothalamus and hindbrain in addition to key feeding reward areas such as the nucleus accumbens and ventral tegmental area. Furthermore, the magnitude of an anorexigenic response to OT and feeding-related activation of the brain OT circuit are modified by the composition and flavor of a diet, as well as by a social context in which a meal is consumed. OT is particularly effective in reducing consumption of carbohydrates and sweet tastants. Pharmacologic, genetic, and pair-feeding studies indicate that OT-elicited weight loss cannot be fully explained by reductions of food intake and that the overall impact of OT on energy balance is also partly a result of OT-elicited changes in lipolysis, energy expenditure, and glucose regulation. Peripheral administration of OT mimics many of its effects when it is given into the central nervous system, raising the questions of whether and to what extent circulating OT acts through peripheral OT receptors to regulate energy balance. Although OT has been found to elicit weight loss in female mice, recent studies have indicated that sex and estrous cycle may impact oxytocinergic modulation of food intake. Despite the overall promising basic research data, attempts to use OT in the clinical setting to combat obesity and overeating have generated somewhat mixed results. The focus of this mini-review is to briefly summarize the role of OT in feeding and metabolism, address gaps and inconsistencies in our knowledge, and discuss some of the limitations to the potential use of chronic OT that should help guide future research on OT as a tailor-made anti-obesity therapeutic.
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Affiliation(s)
- Pawel K Olszewski
- Faculty of Science and Engineering, University of Waikato, Waikato, New Zealand
- Department of Food Science and Nutrition, College of Food, Agricultural and Natural Resource Sciences, University of Minnesota, St Paul, Minnesota, USA
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota, USA
| | - Emily E Noble
- Department of Nutritional Sciences, University of Georgia, Athens, Georgia, USA
| | - Luis Paiva
- Instituto de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile
| | - Yoichi Ueta
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan
| | - James E Blevins
- Department of Veterans Affairs Medical Center, VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Seattle, Washington, USA
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
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Marazziti D, Diep PT, Carter S, Carbone MG. Oxytocin: An Old Hormone, A Novel Psychotropic Drug And Possible Use In Treating Psychiatric Disorders. Curr Med Chem 2022; 29:5615-5687. [PMID: 35894453 DOI: 10.2174/0929867329666220727120646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/17/2022] [Accepted: 04/19/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND Oxytocin is a nonapeptide synthesized in the paraventricular and supraoptic nuclei of the hypothalamus. Historically, this molecule has been involved as a key factor in the formation of infant attachment, maternal behavior and pair bonding and, more generally, in linking social signals with cognition, behaviors and reward. In the last decades, the whole oxytocin system has gained a growing interest as it was proposed to be implicated in etiopathogenesis of several neurodevelopmental and neuropsychiatric disorders. METHODS With the main goal of an in-depth understanding of the oxytocin role in the regulation of different functions and complex behaviors as well as its intriguing implications in different neuropsychiatric disorders, we performed a critical review of the current state of art. We carried out this work through PubMed database up to June 2021 with the search terms: 1) "oxytocin and neuropsychiatric disorders"; 2) "oxytocin and neurodevelopmental disorders"; 3) "oxytocin and anorexia"; 4) "oxytocin and eating disorders"; 5) "oxytocin and obsessive-compulsive disorder"; 6) "oxytocin and schizophrenia"; 7) "oxytocin and depression"; 8) "oxytocin and bipolar disorder"; 9) "oxytocin and psychosis"; 10) "oxytocin and anxiety"; 11) "oxytocin and personality disorder"; 12) "oxytocin and PTSD". RESULTS Biological, genetic, and epigenetic studies highlighted quality and quantity modifications in the expression of oxytocin peptide or in oxytocin receptor isoforms. These alterations would seem to be correlated with a higher risk of presenting several neuropsychiatric disorders belonging to different psychopathological spectra. Collaterally, the exogenous oxytocin administration has shown to ameliorate many neuropsychiatric clinical conditions. CONCLUSION Finally, we briefly analyzed the potential pharmacological use of oxytocin in patient with severe symptomatic SARS-CoV-2 infection due to its anti-inflammatory, anti-oxidative and immunoregulatory properties.
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Affiliation(s)
- Donatella Marazziti
- Department of Clinical and Experimental Medicine, Section of Psychiatry, University of Pisa, Italy.,Saint Camillus International University of Health and Medical Sciences, Rome, Italy
| | - Phuoc-Tan Diep
- Department of Histopathology, Royal Lancaster Infirmary, University Hospitals of Morecambe Bay NHS Foundation Trust, Lancaster, United Kingdom
| | - Sue Carter
- Director Kinsey Institute, Indiana University, Bloomington, IN, USA
| | - Manuel G Carbone
- Department of Medicine and Surgery, Division of Psychiatry, University of Insubria, 21100 Varese, Italy
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Abstract
The mesolimbic dopamine system is the primary neural circuit mediating motivation, reinforcement, and reward-related behavior. The activity of this system and multiple behaviors controlled by it are affected by changes in feeding and body weight, such as fasting, food restriction, or the development of obesity. Multiple different peptides and hormones that have been implicated in the control of feeding and body weight interact with the mesolimbic dopamine system to regulate many different dopamine-dependent, reward-related behaviors. In this review, we summarize the effects of a selected set of feeding-related peptides and hormones acting within the ventral tegmental area and nucleus accumbens to alter feeding, as well as food, drug, and social reward.
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Affiliation(s)
- Anna I. Dunigan
- Department of Biology and Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
| | - Aaron G. Roseberry
- Department of Biology and Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
- Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA
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Ye Q, Nunez J, Zhang X. Oxytocin Receptor-Expressing Neurons in the Paraventricular Thalamus Regulate Feeding Motivation through Excitatory Projections to the Nucleus Accumbens Core. J Neurosci 2022; 42:3949-3964. [PMID: 35387870 PMCID: PMC9097779 DOI: 10.1523/jneurosci.2042-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/27/2022] [Accepted: 03/29/2022] [Indexed: 11/21/2022] Open
Abstract
Oxytocin receptors (OTR) have been found in the paraventricular thalamus (PVT) for the regulation of feeding and maternal behaviors. However, the functional projections of OTR-expressing PVT neurons remain largely unknown. Here, we used chemogenetic and optogenetic tools to test the role of OTR-expressing PVT neurons and their projections in the regulation of food intake in both male and female OTR-Cre mice. We found chemogenetic activation of OTR-expressing PVT neurons promoted food seeking under trials with a progressive ratio schedule of reinforcement. Using Feeding Experimentation Devices for real-time meal measurements, we found chemogenetic activation of OTR-expressing PVT neurons increased meal frequency but not cumulative food intake because of a compensatory decrease in meal sizes. In combination with anterograde neural tracing and slice patch-clamp recordings, we found optogenetic stimulation of PVT OTR terminals excited neurons in the posterior basolateral amygdala (pBLA) and nucleus accumbens core (NAcC) as well as local PVT neurons through monosynaptic glutamatergic transmissions. Photostimulation of OTR-expressing PVT-NAcC projections promoted food-seeking, whereas selective activation of PVT-pBLA projections produced little effect on feeding. In contrast to selective activation of OTR terminals, photostimulation of a broader population of glutamatergic PVT terminals exerted direct excitation followed by indirect lateral inhibition on neurons in both NAcC and anterior basolateral amygdala. Together, these results suggest that OTR-expressing PVT neurons are a distinct population of PVT glutamate neurons that regulate feeding motivation through projections to NAcC.SIGNIFICANCE STATEMENT The paraventricular thalamus plays an important role in the regulation of feeding motivation. However, because of the diversity of paraventricular thalamic neurons, the specific neuron types promoting food motivation remain elusive. In this study, we provide evidence that oxytocin receptor-expressing neurons are a specific group of glutamate neurons that primarily project to the nucleus accumbens core and posterior amygdala. We found that activation of these neurons promotes the motivation for food reward and increases meal frequency through projections to the nucleus accumbens core but not the posterior amygdala. As a result, we postulate that oxytocin receptor-expressing neurons in the paraventricular thalamus and their projections to the nucleus accumbens core mainly regulate feeding motivation but not food consumption.
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Affiliation(s)
- Qiying Ye
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306
| | - Jeremiah Nunez
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306
| | - Xiaobing Zhang
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306
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Levine AS, Jewett DC, Kotz CM, Olszewski PK. Behavioral plasticity: Role of neuropeptides in shaping feeding responses. Appetite 2022; 174:106031. [PMID: 35395362 DOI: 10.1016/j.appet.2022.106031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 03/12/2022] [Accepted: 03/29/2022] [Indexed: 11/28/2022]
Abstract
Behavioral plasticity refers to changes occurring due to external influences on an organism, including adaptation, learning, memory and enduring influences from early life experience. There are 2 types of behavioral plasticity: "developmental", which refers to gene/environment interactions affecting a phenotype, and "activational" which refers to innate physiology and can involve structural physiological changes of the body. In this review, we focus on feeding behavior, and studies involving neuropeptides that influence behavioral plasticity - primarily opioids, orexin, neuropeptide Y, and oxytocin. In each section of the review, we include examples of behavioral plasticity as it relates to actions of these neuropeptides. It can be concluded from this review that eating behavior is influenced by a number of external factors, including time of day, type of food available, energy balance state, and stressors. The reviewed work underscores that environmental factors play a critical role in feeding behavior and energy balance, but changes in eating behavior also result from a multitude of non-environmental factors, such that there can be no single mechanism or variable that can explain ingestive behavior.
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Affiliation(s)
- Allen S Levine
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, 55113, USA.
| | - David C Jewett
- Department of Psychology, University of Wisconsin-Eau Claire, Eau Claire, WI, USA
| | - Catherine M Kotz
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, 55414, USA; Geriatric, Research, Education and Clinical Center, Minneapolis Veterans Affairs Health, Minneapolis, MN, 55417, USA
| | - Pawel K Olszewski
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, 55113, USA; Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, 55414, USA; Faculty of Science and Engineering, University of Waikato, Hamilton, 3240, New Zealand
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14
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Rehn S, Raymond JS, Boakes RA, Bowen MT. Sucrose intake by rats affected by both intraperitoneal oxytocin administration and time of day. Psychopharmacology (Berl) 2022; 239:429-42. [PMID: 34731267 DOI: 10.1007/s00213-021-06014-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 10/20/2021] [Indexed: 10/19/2022]
Abstract
RATIONALE Daily limited access to palatable food or drink at a fixed time is commonly used in rodent models of bingeing. Under these conditions, entrainment may modulate intake patterns. Oxytocin is involved in circadian patterns of intake and, when administered peripherally, reduces sucrose intake. However, oxytocin's effects on intake under limited-access conditions and its potential interaction with entrainment have not been explored. OBJECTIVES This study examined the role of entrainment on intake patterns, oxytocin's effects on sucrose intakes and locomotor activity and whether oxytocin's effects were mediated by its actions at the oxytocin receptor. METHODS Sated rats received daily 1-h access to 10% sucrose solution either at a fixed or varied time of day. Rats received intraperitoneal oxytocin (0 mg/kg, 0.3 mg/kg, 1 mg/kg, 3 mg/kg) prior to sucrose access, and spontaneous locomotor activity was assessed in an open-field test. Rats were then pre-treated with an oxytocin receptor antagonist, L368,899, prior to oxytocin before sucrose access. RESULTS Intake patterns did not differ between fixed- or varied-time presentations; rats consumed more sucrose solution in the middle as opposed to the early-dark phase. Oxytocin dose-dependently reduced sucrose intakes, but also reduced locomotor activity. There was some evidence of partial blockade of oxytocin-induced sucrose intake reductions by L368,899, but the results were unclear. CONCLUSIONS Time of day and oxytocin impact sucrose solution intake under daily limited access in rats and the sedative-like effects of oxytocin should be considered in future studies on oxytocin and food intake.
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15
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Lei Y, Wang D, Bai Y, Nougaisse J, Weintraub NL, Guo M, Lu XY. Leptin enhances social motivation and reverses chronic unpredictable stress-induced social anhedonia during adolescence. Mol Psychiatry 2022; 27:4948-58. [PMID: 36138127 DOI: 10.1038/s41380-022-01778-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 08/12/2022] [Accepted: 09/02/2022] [Indexed: 01/19/2023]
Abstract
Social anhedonia, a loss of interest and pleasure in social interactions, is a common symptom of major depression as well as other psychiatric disorders. Depression can occur at any age, but typically emerges in adolescence or early adulthood, which represents a sensitive period for social interaction that is vulnerable to stress. In this study, we evaluated social interaction reward using a conditioned place preference (CPP) paradigm in adolescent male and female mice. Adolescent mice of both sexes exhibited a preference for the social interaction-associated context. Chronic unpredictable stress (CUS) impaired the development of CPP for social interaction, mimicking social anhedonia in depressed adolescents. Conversely, administration of leptin, an adipocyte-derived hormone, enhanced social interaction-induced CPP in non-stressed control mice and reversed social anhedonia in CUS mice. By dissecting the motivational processes of social CPP into social approach and isolation avoidance components, we demonstrated that leptin treatment increased isolation aversion without overt social reward effect. Further mechanistic exploration revealed that leptin stimulated oxytocin gene transcription in the paraventricular nucleus of the hypothalamus, while oxytocin receptor blockade abolished the leptin-induced enhancement of socially-induced CPP. These results establish that chronic unpredictable stress can be used to study social anhedonia in adolescent mice and provide evidence that leptin modulates social motivation possibly via increasing oxytocin synthesis and oxytocin receptor activation.
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Abstract
Obesity is a growing health concern, as it increases risk for heart disease, hypertension, type 2 diabetes, cancer, COVID-19 related hospitalizations and mortality. However, current weight loss therapies are often associated with psychiatric or cardiovascular side effects or poor tolerability that limit their long-term use. The hypothalamic neuropeptide, oxytocin (OT), mediates a wide range of physiologic actions, which include reproductive behavior, formation of prosocial behaviors and control of body weight. We and others have shown that OT circumvents leptin resistance and elicits weight loss in diet-induced obese rodents and non-human primates by reducing both food intake and increasing energy expenditure (EE). Chronic intranasal OT also elicits promising effects on weight loss in obese humans. This review evaluates the potential use of OT as a therapeutic strategy to treat obesity in rodents, non-human primates, and humans, and identifies potential mechanisms that mediate this effect.
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Affiliation(s)
- JingJing Niu
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States.,Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
| | - Jenny Tong
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States.,Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
| | - James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States.,Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, United States
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17
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Abstract
There has been a long history of research on the effects of oxytocin on feeding behaviour. The classic-held view is that the neurohormone is anorexigenic at least in rodents, although the data for humans are not so clear cut. Likewise, a physiological role for oxytocin is disputed. Thus, although pharmacological, anatomical and physiological data suggest oxytocin may have a function in satiety signalling, this view is not supported by the latest research using the genetic recording and manipulation of oxytocin neurones. Here, we avoid a discussion of the pharmacological effects of oxytocin and examine evidence, from both sides of the argument, concerning whether the endogenous oxytocin system has a role in the regulation of normal feeding.
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Affiliation(s)
- Amy A Worth
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Simon M Luckman
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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18
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Anekonda VT, Thompson BW, Ho JM, Roberts ZS, Edwards MM, Nguyen HK, Dodson AD, Wolden-Hanson T, Chukri DW, Herbertson AJ, Graham JL, Havel PJ, Wietecha TA, O’Brien KD, Blevins JE. Hindbrain Administration of Oxytocin Reduces Food Intake, Weight Gain and Activates Catecholamine Neurons in the Hindbrain Nucleus of the Solitary Tract in Rats. J Clin Med 2021; 10:5078. [PMID: 34768597 PMCID: PMC8584350 DOI: 10.3390/jcm10215078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 11/16/2022] Open
Abstract
Existing studies show that CNS oxytocin (OT) signaling is important in the control of energy balance, but it is unclear which neurons may contribute to these effects. Our goals were to examine (1) the dose-response effects of acute OT administration into the third (3V; forebrain) and fourth (4V; hindbrain) ventricles to assess sensitivity to OT in forebrain and hindbrain sites, (2) the extent to which chronic 4V administration of OT reduces weight gain associated with the progression of diet-induced obesity, and (3) whether nucleus tractus solitarius (NTS) catecholamine neurons are downstream targets of 4V OT. Initially, we examined the dose-response effects of 3V and 4V OT (0.04, 0.2, 1, or 5 μg). 3V and 4V OT (5 μg) suppressed 0.5-h food intake by 71.7 ± 6.0% and 60 ± 12.9%, respectively. 4V OT (0.04, 0.2, 1 μg) reduced food intake by 30.9 ± 12.9, 42.1 ± 9.4, and 56.4 ± 9.0%, respectively, whereas 3V administration of OT (1 μg) was only effective at reducing 0.5-h food intake by 38.3 ± 10.9%. We subsequently found that chronic 4V OT infusion, as with chronic 3V infusion, reduced body weight gain (specific to fat mass) and tended to reduce plasma leptin in high-fat diet (HFD)-fed rats, in part, through a reduction in energy intake. Lastly, we determined that 4V OT increased the number of hindbrain caudal NTS Fos (+) neurons (156 ± 25) relative to vehicle (12 ± 3). The 4V OT also induced Fos in tyrosine hydroxylase (TH; marker of catecholamine neurons) (+) neurons (25 ± 7%) relative to vehicle (0.8 ± 0.3%). Collectively, these findings support the hypothesis that OT within the hindbrain is effective at reducing food intake, weight gain, and adiposity and that NTS catecholamine neurons in addition to non-catecholaminergic neurons are downstream targets of CNS OT.
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Affiliation(s)
- Vishwanath T. Anekonda
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Benjamin W. Thompson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Jacqueline M. Ho
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA;
| | - Zachary S. Roberts
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Melise M. Edwards
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Ha K. Nguyen
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Andrew D. Dodson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Tami Wolden-Hanson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Daniel W. Chukri
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - Adam J. Herbertson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
| | - James L. Graham
- Department of Nutrition and Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; (J.L.G.); (P.J.H.)
| | - Peter J. Havel
- Department of Nutrition and Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; (J.L.G.); (P.J.H.)
| | - Tomasz A. Wietecha
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA;
- UW Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, WA 98109, USA;
| | - Kevin D. O’Brien
- UW Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, WA 98109, USA;
- Division of Cardiology, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - James E. Blevins
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; (V.T.A.); (B.W.T.); (J.M.H.); (Z.S.R.); (M.M.E.); (H.K.N.); (A.D.D.); (T.W.-H.); (D.W.C.); (A.J.H.)
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA;
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19
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Liu CM, Spaulding MO, Rea JJ, Noble EE, Kanoski SE. Oxytocin and Food Intake Control: Neural, Behavioral, and Signaling Mechanisms. Int J Mol Sci 2021; 22:10859. [PMID: 34639199 DOI: 10.3390/ijms221910859] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 09/29/2021] [Accepted: 10/03/2021] [Indexed: 11/16/2022] Open
Abstract
The neuropeptide oxytocin is produced in the paraventricular hypothalamic nucleus and the supraoptic nucleus of the hypothalamus. In addition to its extensively studied influence on social behavior and reproductive function, central oxytocin signaling potently reduces food intake in both humans and animal models and has potential therapeutic use for obesity treatment. In this review, we highlight rodent model research that illuminates various neural, behavioral, and signaling mechanisms through which oxytocin’s anorexigenic effects occur. The research supports a framework through which oxytocin reduces food intake via amplification of within-meal physiological satiation signals rather than by altering between-meal interoceptive hunger and satiety states. We also emphasize the distributed neural sites of action for oxytocin’s effects on food intake and review evidence supporting the notion that central oxytocin is communicated throughout the brain, at least in part, through humoral-like volume transmission. Finally, we highlight mechanisms through which oxytocin interacts with various energy balance-associated neuropeptide and endocrine systems (e.g., agouti-related peptide, melanin-concentrating hormone, leptin), as well as the behavioral mechanisms through which oxytocin inhibits food intake, including effects on nutrient-specific ingestion, meal size control, food reward-motivated responses, and competing motivations.
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20
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Klockars A, Pal T, Levine AS, Olszewski PK. Neural Basis of Dysregulation of Palatability-Driven Appetite in Autism. Curr Nutr Rep 2021; 10:391-398. [PMID: 34417997 DOI: 10.1007/s13668-021-00368-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2021] [Indexed: 11/30/2022]
Abstract
PURPOSE OF REVIEW In research on autism spectrum disorder (ASD), cognitive, speech- and anxiety-related impairments have been the focus of the majority of studies. One consistently reported ASD symptom that has rarely attracted attention is disordered appetite. The goal of this paper is to assess whether ASD-related dysregulation of food intake impacts consumption of palatable foods, including sugar. RECENT FINDINGS Aberrant neural processing at the reward system level is at least partially responsible for excessive intake of palatable tastants, including sugar. Impaired oxytocin (OT) signaling likely contributes to the magnitude of this overconsumption. Since intake for reward is generally elevated in individuals with ASD, one strategy to curb sugar overconsumption might utilize presentation of alternative palatable food choices that are more nutritionally adequate than sucrose. Furthermore, OT, which is clinically tested to alleviate other ASD symptoms, might be an effective tool to curb overconsumption of sugar, as well as - likely - of other excessively ingested palatable foods, especially those that have sweet taste.
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Affiliation(s)
- Anica Klockars
- Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand
| | - Tapasya Pal
- Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand
| | - Allen S Levine
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA.
| | - Pawel K Olszewski
- Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand.,Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, USA.,Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA
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21
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He Z, Zhang L, Hou W, Zhang X, Young LJ, Li L, Liu L, Ma H, Xun Y, Lv Z, Li Y, Jia R, Li J, Tai F. Paraventricular Nucleus Oxytocin Subsystems Promote Active Paternal Behaviors in Mandarin Voles. J Neurosci 2021; 41:6699-6713. [PMID: 34226275 PMCID: PMC8336703 DOI: 10.1523/jneurosci.2864-20.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 11/21/2022] Open
Abstract
Paternal care plays a critical role in the development of brain and behaviors in offspring in monogamous species. However, the neurobiological mechanisms, especially the neuronal circuity, underlying paternal care is largely unknown. Using socially monogamous male mandarin voles (Microtus mandarinus) with high levels of paternal care, we found that paraventricular nucleus of the hypothalamus (PVN) to ventral tegmental area (VTA) or nucleus accumbens (NAc) oxytocin (OT) neurons are activated during paternal care. Chemogenetic activation/inhibition of the PVN OT projection to VTA promoted/decreased paternal care, respectively. Chemogenetic inhibition of the PVN to VTA OT pathway reduced dopamine (DA) release in the NAc of male mandarin voles during licking and grooming of pups as revealed by in vivo fiber photometry. Optogenetic activation/inhibition of the VTA to NAc DA pathway possibly enhanced/suppressed paternal behaviors, respectively. Furthermore, chemogenetic activation/inhibition of PVN to NAc OT circuit enhanced/inhibited paternal care. This finding is a first step toward delineating the neuronal circuity underlying paternal care and may have implications for treating abnormalities in paternal care associated with paternal postpartum depression or paternal abuse.SIGNIFICANCE STATEMENT Paternal behavior is essential for offspring survival and development in some mammalian species. However, the circuit mechanisms underlying the paternal brain are poorly understood. We show that manipulation of paraventricular nucleus of the hypothalamus (PVN) to ventral tegmental area (VTA) oxytocin (OT) projections as well as VTA to nucleus accumbens (NAc) DA projections promote paternal behaviors. Inhibition the PVN to VTA OT pathway reduces DA release in the NAc during pup licking and grooming. PVN to NAc OT circuit is also essential for paternal behaviors. Our findings identify two new neural circuits that modulate paternal behaviors.
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Affiliation(s)
- Zhixiong He
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Lizi Zhang
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Wenjuan Hou
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Xin Zhang
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Larry J Young
- Department of Psychiatry and Behavioral Sciences, Silvio O. Conte Center for Oxytocin and Social Cognition, Center for Translational Social Neuroscience, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia 30033
- Center for Social Neural Networks, University of Tsukuba, Tsukuba 305-8555, Japan
| | - Laifu Li
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Limin Liu
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Huan Ma
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Yufeng Xun
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Zijian Lv
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Yitong Li
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Rui Jia
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Jingang Li
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Fadao Tai
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
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22
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Barrett LR, Nunez J, Zhang X. Oxytocin activation of paraventricular thalamic neurons promotes feeding motivation to attenuate stress-induced hypophagia. Neuropsychopharmacology 2021; 46:1045-1056. [PMID: 33495546 PMCID: PMC8114915 DOI: 10.1038/s41386-021-00961-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/29/2020] [Indexed: 01/30/2023]
Abstract
The neuropeptide oxytocin (OT) regulates important brain functions including feeding through activating OT receptors in multiple brain areas. Both OT fibers and OT receptors have been reported in the paraventricular thalamus (PVT), an area that was revealed to be important for the control of emotion, motivation, and food intake. However, the function and modulation of PVT OT signaling remain unknown. Here, we used a progressive ratio (PR) schedule of reinforcement to examine the role of PVT OT signaling in regulating the motivation for food and patch-clamp electrophysiology to study the modulation of OT on PVT neurons in brain slices. We demonstrate that PVT OT administration increases active lever presses to earn food rewards in both male and female mice under PR trials and OT receptor antagonist atosiban inhibits OT-induced increase in motivated lever presses. However, intra-PVT OT infusion does not affect food intake in normal conditions but attenuates hypophagia induced by stress and anxiety. Using patch-clamp recordings, we find OT induces long-lasting excitatory effects on neurons in all PVT regions, especially the middle to posterior PVT. OT not only evokes tonic inward currents but also increases the frequency of spontaneous excitatory postsynaptic currents on PVT neurons. The excitatory effect of OT on PVT neurons is mimicked by the specific OT receptor agonist [Thr4, Gly7]-oxytocin (TGOT) and blocked by OT receptor antagonist atosiban. Together, our study reveals a critical role of PVT OT signaling in promoting feeding motivation to attenuate stress-induced hypophagia through exciting PVT neurons.
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Affiliation(s)
- Lily R. Barrett
- grid.255986.50000 0004 0472 0419Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306 USA
| | - Jeremiah Nunez
- grid.255986.50000 0004 0472 0419Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306 USA
| | - Xiaobing Zhang
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL, 32306, USA.
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Yang B. When to Stop Eating: An Auxiliary Brake on Food Consumption from the Nucleus Accumbens. J Neurosci 2021; 41:1847-9. [PMID: 33658336 DOI: 10.1523/JNEUROSCI.1666-20.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 12/24/2020] [Accepted: 12/28/2020] [Indexed: 12/17/2022] Open
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Sundar M, Patel D, Young Z, Leong KC. Oxytocin and Addiction: Potential Glutamatergic Mechanisms. Int J Mol Sci 2021; 22:ijms22052405. [PMID: 33673694 PMCID: PMC7957657 DOI: 10.3390/ijms22052405] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/25/2021] [Accepted: 02/25/2021] [Indexed: 11/16/2022] Open
Abstract
Recently, oxytocin (OXT) has been investigated for its potential therapeutic role in addiction. OXT has been found to diminish various drug-seeking and drug-induced behaviors. Although its behavioral effects are well-established, there is not much consensus on how this neuropeptide exerts its effects. Previous research has given thought to how dopamine (DA) may be involved in oxytocinergic mechanisms, but there has not been as strong of a focus on the role that glutamate (Glu) has. The glutamatergic system is critical for the processing of rewards and the disruption of glutamatergic projections produces the behaviors seen in drug addicts. We introduce the idea that OXT has direct effects on Glu transmission within the reward processing pathway. Thus, OXT may reduce addictive behaviors by restoring abnormal drug-induced changes in the glutamatergic system and in its interactions with other neurotransmitters. This review offers insight into the mechanisms through which a potentially viable therapeutic target, OXT, could be used to reduce addiction-related behaviors.
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Abstract
The hypothalamic peptide oxytocin has been increasingly recognized as a hormone and neurotransmitter with important effects on energy intake, metabolism, and body weight and is under investigation as a potential novel therapeutic agent for obesity. The main neurons producing oxytocin and expressing the oxytocin receptor are strategically located in brain areas known to be critically involved in homeostatic energy balance as well as hedonic and motivational aspects of eating behavior. In this chapter, we will review the central and peripheral physiology of oxytocin and the interaction of oxytocin with key hormones and neural circuitries that affect food intake and metabolism. Next, we will synthesize the available data on endogenous oxytocin levels related to caloric intake, body weight, and metabolic status. We will then review the effects of exogenous oxytocin administration on eating behavior, body weight, and metabolism in humans, including in healthy individuals as well as specific populations with suspected perturbations involving oxytocin pathways. Finally, we will address the promise and fundamental challenges of translating this line of research to clinical care.
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Affiliation(s)
- Liya Kerem
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States; Division of Pediatric Endocrinology, Massachusetts General Hospital for Children, Boston, MA, United States
| | - Elizabeth A Lawson
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States.
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Patel D, Sundar M, Lorenz E, Leong KC. Oxytocin Attenuates Expression, but Not Acquisition, of Sucrose Conditioned Place Preference in Rats. Front Behav Neurosci 2020; 14:603232. [PMID: 33384589 PMCID: PMC7769941 DOI: 10.3389/fnbeh.2020.603232] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 11/17/2020] [Indexed: 01/02/2023] Open
Abstract
Maladaptation of reward processing for natural rewards, such as sucrose or sugar, may play a role in the development of diseases such as obesity and diabetes. Furthermore, uncovering mechanisms to disrupt or reverse maladaptation of reward-seeking behaviors for natural reinforcers can provide insight into treatment of such diseases, as well as disorders such as addiction. As such, studying the effects of potential pharmacotherapeutics on maladaptive sugar-seeking behavior offers valuable clinical significance. Sucrose conditioned place preference (CPP) paradigms can offer insight into aspects of reward processes as it provides a way to assess acquisition and expression of context-reward associations. The present study examined the effect of peripheral oxytocin injections on sucrose CPP in rats. Oxytocin, when administered prior to CPP test, attenuated expression of sucrose CPP. However, oxytocin, when administered during sucrose conditioning, did not affect subsequent place preference. These findings suggest oxytocin sufficiently attenuates expression of sucrose-associated place preference.
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Affiliation(s)
- Devon Patel
- Department of Psychology, Trinity University, San Antonio, TX, United States
| | - Megana Sundar
- Department of Psychology, Trinity University, San Antonio, TX, United States
| | - Eva Lorenz
- Department of Psychology, Trinity University, San Antonio, TX, United States
| | - Kah-Chung Leong
- Department of Psychology, Trinity University, San Antonio, TX, United States
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Liu CM, Hsu TM, Suarez AN, Subramanian KS, Fatemi RA, Cortella AM, Noble EE, Roitman MF, Kanoski SE. Central oxytocin signaling inhibits food reward-motivated behaviors and VTA dopamine responses to food-predictive cues in male rats. Horm Behav 2020; 126:104855. [PMID: 32991888 PMCID: PMC7757852 DOI: 10.1016/j.yhbeh.2020.104855] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/02/2020] [Accepted: 08/23/2020] [Indexed: 01/08/2023]
Abstract
Oxytocin potently reduces food intake and is a potential target system for obesity treatment. A better understanding of the behavioral and neurobiological mechanisms mediating oxytocin's anorexigenic effects may guide more effective obesity pharmacotherapy development. The present study examined the effects of central (lateral intracerebroventricular [ICV]) administration of oxytocin in rats on motivated responding for palatable food. Various conditioning procedures were employed to measure distinct appetitive behavioral domains, including food seeking in the absence of consumption (conditioned place preference expression), impulsive responding for food (differential reinforcement of low rates of responding), effort-based appetitive decision making (high-effort palatable vs. low-effort bland food), and sucrose reward value encoding following a motivational shift (incentive learning). Results reveal that ICV oxytocin potently reduces food-seeking behavior, impulsivity, and effort-based palatable food choice, yet does not influence encoding of sucrose reward value in the incentive learning task. To investigate a potential neurobiological mechanism mediating these behavioral outcomes, we utilized in vivo fiber photometry in ventral tegmental area (VTA) dopamine neurons to examine oxytocin's effect on phasic dopamine neuron responses to sucrose-predictive Pavlovian cues. Results reveal that ICV oxytocin significantly reduced food cue-evoked dopamine neuron activity. Collectively, these data reveal that central oxytocin signaling inhibits various obesity-relevant conditioned appetitive behaviors, potentially via reductions in food cue-driven phasic dopamine neural responses in the VTA.
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Affiliation(s)
- Clarissa M Liu
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States
| | - Ted M Hsu
- Department of Psychology, University of Illinois at Chicago, 1007 W. Harrison St., Chicago, IL 60607-7137, United States
| | - Andrea N Suarez
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States
| | - Keshav S Subramanian
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States
| | - Ryan A Fatemi
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States
| | - Alyssa M Cortella
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States
| | - Emily E Noble
- Department of Foods and Nutrition, University of Georgia, 129 Barrow Hall, Athens, GA 30602, United States
| | - Mitchell F Roitman
- Department of Psychology, University of Illinois at Chicago, 1007 W. Harrison St., Chicago, IL 60607-7137, United States
| | - Scott E Kanoski
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, 3616 Trousdale Parkway, AHF 252, Los Angeles, CA 90089, United States.
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Mobasher MW, Eid HF, Soliman AM, El-hanafi HM, El-makawi SM. Serum Oxytocin Level Among Male Patients With Opioid Dependence and Its Relation to Craving. Addictive Disorders & Their Treatment 2021; 20:132-140. [DOI: 10.1097/adt.0000000000000231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Narmaki E, Borazjani M, Ataie-Jafari A, Hariri N, Doost AH, Qorbani M, Saidpour A. The combined effects of probiotics and restricted calorie diet on the anthropometric indices, eating behavior, and hormone levels of obese women with food addiction : a randomized clinical trial. Nutr Neurosci 2020; 25:963-975. [PMID: 33054635 DOI: 10.1080/1028415x.2020.1826763] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND AND AIM Food addiction (FA) is an important contributor to obesity. Alterations in gut microbiota (GM) diversity and composition have also been proposed to play a pivotal role in obesity pathogenesis. This trial aimed to assess the effects of probiotic supplementation on the anthropometric indices, eating behavior, and hormone levels of obese women with FA. METHODS This randomized, double-blind, placebo-controlled clinical trial was conducted among obese women with FA. Participants (n = 62) received a restricted calorie diet (RCD) plus either probiotic, or placebo for 12 weeks. Anthropometric measurements, biochemical markers, eating behavior and appetite were assessed during the study period. RESULTS Probiotics administration significantly reduced weight, body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), body fat percentage (BFP), and trunk fat percentage (TFP) compared to the placebo group (p < 0.001). Also, a significant improvement was observed in eating behavior in the probiotic group compared to the placebo group (p < 0.001).Serum levels of oxytocin increased and NPY decreased significantly in the probiotic group compared to the placebo group (p = 0.02, p = 0.002, respectively). Moreover, leptin level significantly decreased in the probiotic group compared to the baseline values (p < 0.001), while probiotics did not cause a greater significant reduction in leptin level, compared to the placebo group. CONCLUSION Multi-probiotic supplementation may have beneficial effects on anthropometric indices, eating behavior, and some appetite-regulating hormones in obese women with FA.Trial registration: Iranian Registry of Clinical Trials identifier: IRCT20131228015968N5.
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Affiliation(s)
- Elham Narmaki
- National Nutrition and Food Technology Research Institute, Department of Clinical Nutrition & Dietetics, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohaddeseh Borazjani
- School of Nutrition and Food Science, Shiraz University of Medical Science, Iran
| | - Asal Ataie-Jafari
- Department of Nutrition, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Nastaran Hariri
- National Nutrition and Food Technology Research Institute, Department of Clinical Nutrition & Dietetics, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Azita Hekmat Doost
- National Nutrition and Food Technology Research Institute, Department of Clinical Nutrition & Dietetics, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mostafa Qorbani
- Non-communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran
| | - Atoosa Saidpour
- National Nutrition and Food Technology Research Institute, Department of Clinical Nutrition & Dietetics, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Wald HS, Chandra A, Kalluri A, Ong ZY, Hayes MR, Grill HJ. NTS and VTA oxytocin reduces food motivation and food seeking. Am J Physiol Regul Integr Comp Physiol 2020; 319:R673-R683. [PMID: 33026822 DOI: 10.1152/ajpregu.00201.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Oxytocin (OT) is a neuropeptide whose central receptor-mediated actions include reducing food intake. One mechanism of its behavioral action is the amplification of the feeding inhibitory effects of gastrointestinal (GI) satiation signals processed by hindbrain neurons. OT treatment also reduces carbohydrate intake in humans and rodents, and correspondingly, deficits in central OT receptor (OT-R) signaling increase sucrose self-administration. This suggests that additional processes contribute to central OT effects on feeding. This study investigated the hypothesis that central OT reduces food intake by decreasing food seeking and food motivation. As central OT-Rs are expressed widely, a related focus was to assess the role of one or more OT-R-expressing nuclei in food motivation and food-seeking behavior. OT was delivered to the lateral ventricle (LV), nucleus tractus solitarius (NTS), or ventral tegmental area (VTA), and a progressive ratio (PR) schedule of operant reinforcement and an operant reinstatement paradigm were used to measure motivated feeding behavior and food-seeking behavior, respectively. OT delivered to the LV, NTS, or VTA reduced 1) motivation to work for food and 2) reinstatement of food-seeking behavior. Results provide a novel and additional interpretation for central OT-driven food intake inhibition to include the reduction of food motivation and food seeking.
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Affiliation(s)
- Hallie S Wald
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ananya Chandra
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Anita Kalluri
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Zhi Yi Ong
- School of Psychology, University of New South Wales, Sydney, Australia
| | - Matthew R Hayes
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Harvey J Grill
- Department of Psychology, Institute of Diabetes Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania
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Romano A, Friuli M, Cifani C, Gaetani S. Oxytocin in the neural control of eating: At the crossroad between homeostatic and non-homeostatic signals. Neuropharmacology 2020; 171:108082. [PMID: 32259527 DOI: 10.1016/j.neuropharm.2020.108082] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 03/10/2020] [Accepted: 03/30/2020] [Indexed: 12/21/2022]
Abstract
The understanding of the biological substrates regulating feeding behavior is relevant to address the health problems related to food overconsumption. Several studies have expanded the conventional view of the homeostatic regulation of body weight mainly orchestrated by the hypothalamus, to include also the non-homeostatic control of appetite. Such processes include food reward and are mainly coordinated by the activation of the central mesolimbic dopaminergic pathway. The identification of endogenous systems acting as a bridge between homoeostatic and non-homeostatic pathways might represent a significant step toward the development of drugs for the treatment of aberrant eating patterns. Oxytocin is a hypothalamic hormone that is directly secreted into the brain and reaches the blood circulation through the neurohypophysis. Oxytocin regulates a variety of physiologic functions, including eating and metabolism. In the last years both preclinical and clinical studies well characterized oxytocin for its effects in reducing food intake and body weight. In the present review we summarize the role played by oxytocin in the control of both homeostatic and non-homeostatic eating, within cognitive, metabolic and reward mechanisms, to mostly highlight its potential therapeutic effects as a new pharmacological approach for the development of drugs for eating disorders. We conclude that the central oxytocinergic system is possibly one of the mechanisms that coordinate energy balance at the crossroads between homeostatic and non-homeostatic mechanisms. This concept should foster studies aimed at exploring the possible exploitation of oxytocin in the treatment of aberrant eating patterns. This article is part of the special issue on Neuropeptides.
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Affiliation(s)
- Adele Romano
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - Marzia Friuli
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy
| | - Carlo Cifani
- School of Pharmacy, Pharmacology Unit, University of Camerino, via Madonna delle Carceri, 9, 62032, Camerino, MC, Italy
| | - Silvana Gaetani
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, P.le Aldo Moro 5, 00185, Rome, Italy.
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Abstract
There is growing evidence that oxytocin (OXT), a hypothalamic hormone well recognized for its effects in inducing parturition and lactation, has important metabolic effects in both sexes. The purpose of this review is to summarize the physiologic effects of OXT on metabolism and to explore its therapeutic potential for metabolic disorders. In model systems, OXT promotes weight loss by decreasing energy intake. Pair-feeding studies suggest that OXT-induced weight loss may also be partly due to increased energy expenditure and/or lipolysis. In humans, OXT appears to modulate both homeostatic and reward-driven food intake, although the observed response depends on nutrient milieu (eg, obese vs. nonobese), clinical characteristics (eg, sex), and experimental paradigm. In animal models, OXT is anabolic to muscle and bone, which is consistent with OXT-induced weight loss occurring primarily via fat loss. In some human observational studies, circulating OXT concentrations are also positively associated with lean mass and bone mineral density. The impact of exogenous OXT on human obesity is the focus of ongoing investigation. Future randomized, placebo-controlled clinical trials in humans should include rigorous, standardized, and detailed assessments of adherence, adverse effects, pharmacokinetics/pharmacodynamics, and efficacy in the diverse populations that may benefit from OXT, in particular those in whom hypothalamic OXT signaling may be abnormal or impaired (eg, individuals with Sim1 deficiency, Prader-Willi syndrome, or craniopharyngioma). Future studies will also have the opportunity to investigate the characteristics of new OXT mimetic peptides and the obligation to consider long-term effects, especially when OXT is given to children and adolescents. (Endocrine Reviews XX: XX - XX, 2020).
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Affiliation(s)
- Shana E McCormack
- Neuroendocrine Center, Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.,Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, Washington.,Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, Washington
| | - Elizabeth A Lawson
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts.,Department of Medicine, Harvard Medical School, Boston, Massachusetts
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Lawson EA, Olszewski PK, Weller A, Blevins JE. The role of oxytocin in regulation of appetitive behaviour, body weight and glucose homeostasis. J Neuroendocrinol 2020; 32:e12805. [PMID: 31657509 PMCID: PMC7186135 DOI: 10.1111/jne.12805] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/14/2019] [Accepted: 10/24/2019] [Indexed: 12/28/2022]
Abstract
Obesity and its associated complications have reached epidemic proportions in the USA and also worldwide, highlighting the need for new and more effective treatments. Although the neuropeptide oxytocin (OXT) is well recognised for its peripheral effects on reproductive behaviour, the release of OXT from somatodendrites and axonal terminals within the central nervous system (CNS) is also implicated in the control of energy balance. In this review, we summarise historical data highlighting the effects of exogenous OXT as a short-term regulator of food intake in a context-specific manner and the receptor populations that may mediate these effects. We also describe what is known about the physiological role of endogenous OXT in the control of energy balance and whether serum and brain levels of OXT relate to obesity on a consistent basis across animal models and humans with obesity. We describe recent data on the effectiveness of chronic CNS administration of OXT to decrease food intake and weight gain or to elicit weight loss in diet-induced obese (DIO) and genetically obese mice and rats. Of clinical importance is the finding that chronic central and peripheral OXT treatments both evoke weight loss in obese animal models with impaired leptin signalling at doses that are not associated with visceral illness, tachyphylaxis or adverse cardiovascular effects. Moreover, these results have been largely recapitulated following chronic s.c. or intranasal treatment in DIO non-human primates (rhesus monkeys) and obese humans, respectively. We also identify plausible mechanisms that contribute to the effects of OXT on body weight and glucose homeostasis in rodents, non-human primates and humans. We conclude by describing the ongoing challenges that remain before OXT-based therapeutics can be used as a long-term strategy to treat obesity in humans.
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Affiliation(s)
- Elizabeth A Lawson
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Pawel K Olszewski
- Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand
- Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, MN, USA
| | - Aron Weller
- Psychology Department and Gonda Brain Research Center, Bar Ilan University, Ramat-Gan, Israel
| | - James E Blevins
- Department of Veterans Affairs Medical Center, Office of Research and Development Medical Research Service, VA Puget Sound Health Care System, Seattle, WA, USA
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
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Hume C, Leng G. Oxytocin neurons: integrators of hypothalamic and brainstem circuits in the regulation of macronutrient-specific satiety. Current Opinion in Physiology 2019. [DOI: 10.1016/j.cophys.2019.10.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kerem L, Hadjikhani N, Holsen L, Lawson EA, Plessow F. Oxytocin reduces the functional connectivity between brain regions involved in eating behavior in men with overweight and obesity. Int J Obes (Lond) 2019; 44:980-989. [PMID: 31740723 PMCID: PMC7192759 DOI: 10.1038/s41366-019-0489-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 10/11/2019] [Accepted: 10/31/2019] [Indexed: 02/06/2023]
Abstract
Background: Oxytocin (OXT), shown to decrease food intake in animal models and men, is a promising novel treatment for obesity. We have shown that in men with overweight and obesity, intranasal (IN) OXT reduced the functional magnetic resonance imaging (fMRI) blood oxygenation level-dependent signal in the ventral tegmental area (VTA), the origin of the mesolimbic dopaminergic reward system, in response to high-calorie food vs. non-food images. Here, we employed functional connectivity fMRI analysis, which measures the synchrony in activation between neural systems in a context-dependent manner. We hypothesized that OXT would attenuate the functional connectivity of the VTA with key food motivation brain areas only when participants viewed high-calorie food stimuli. Methods: This randomized, double-blind, placebo-controlled crossover study of 24 IU IN OXT included 10 men with overweight or obesity (mean±SEM BMI: 28.9±0.8 kg/m2). Following drug administration, subjects completed an fMRI food motivation paradigm including images of high and low-calorie foods, non-food objects, and fixation stimuli. A psychophysiological interaction analysis was performed with the VTA as seed region. Results: Following OXT administration, compared with placebo, participants exhibited significantly attenuated functional connectivity between the VTA and the insula, oral somatosensory cortex, amygdala, hippocampus, operculum, and middle temporal gyrus in response to viewing high-calorie foods (Z≥3.1, cluster-corrected, p<0.05). There was no difference in functional connectivity between VTA and these brain areas when comparing OXT and placebo for low-calorie food, non-food, and fixation images. Conclusion: In men with overweight and obesity, OXT attenuates the functional connectivity between the VTA and food motivation brain regions in response to high-calorie visual food images. These findings could partially explain the observed anorexigenic effect of OXT, providing insight into the mechanism through which OXT ameliorates food cue-induced reward anticipation in patients with obesity. Additional studies are ongoing to further delineate the anorexigenic effect of OXT in obesity.
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Affiliation(s)
- Liya Kerem
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.,Division of Pediatric Endocrinology, Massachusetts General Hospital for Children, Boston, MA, USA
| | - Nouchine Hadjikhani
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Boston, MA, USA.,Gillberg Neuropsychiatry Center, University of Gothenburg, Gothenburg, Sweden
| | - Laura Holsen
- Division of Women's Health, Department of Medicine and Department of Psychiatry, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Elizabeth A Lawson
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Franziska Plessow
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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Liu CM, Davis EA, Suarez AN, Wood RI, Noble EE, Kanoski SE. Sex Differences and Estrous Influences on Oxytocin Control of Food Intake. Neuroscience 2019; 447:63-73. [PMID: 31738883 DOI: 10.1016/j.neuroscience.2019.10.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/08/2019] [Accepted: 10/10/2019] [Indexed: 10/25/2022]
Abstract
Central oxytocin potently reduces food intake and is being pursued as a clinical treatment for obesity. While sexually dimorphic effects have been described for the effects of oxytocin on several behavioral outcomes, the role of sex in central oxytocin modulation of feeding behavior is poorly understood. Here we investigated the effects of sex, estrous cycle stage, and female sex hormones (estrogen, progesterone) on central oxytocin-mediated reduction of food intake in rats. Results show that while intracerebroventricular (ICV) oxytocin potently reduces chow intake in both male and female rats, these effects were more pronounced in males than in females. We next examined whether estrous cycle stage affects oxytocin's food intake-reducing effects in females. Results show that ICV oxytocin administration significantly reduces food intake during all estrous cycle stages except proestrous, suggesting that female sex hormones may modulate the feeding effects of oxytocin. Indeed, additional results reveal that estrogen, but not progesterone replacement, in ovariectomized rats abolishes oxytocin-mediated reductions in chow intake. Lastly, oxytocin receptor mRNA (Oxtr) quantification (via quantitative PCR) and anatomical localization (via fluorescent in situ hybridization) in previously established sites of action for oxytocin control of food intake revealed comparable Oxtr expression between male and female rats, suggesting that observed sex and estrous differences may be based on variations in ligand availability and/or binding. Overall, these data show that estrogen reduces the effectiveness of central oxytocin to inhibit food intake, suggesting that sex hormones and estrous cycle should be considered in clinical investigations of oxytocin for obesity treatment.
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Affiliation(s)
- Clarissa M Liu
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, United States
| | - Elizabeth A Davis
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, United States
| | - Andrea N Suarez
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, United States
| | - Ruth I Wood
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Integrative Anatomical Sciences, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - Emily E Noble
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, United States; Department of Foods and Nutrition, University of Georgia, Athens, GA, United States.
| | - Scott E Kanoski
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States; Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, United States.
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Burmester V, Gibson EL, Butler G, Bailey A, Terry P. Oxytocin reduces post-stress sweet snack intake in women without attenuating salivary cortisol. Physiol Behav 2019; 212:112704. [PMID: 31628930 DOI: 10.1016/j.physbeh.2019.112704] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/30/2019] [Accepted: 10/07/2019] [Indexed: 10/25/2022]
Abstract
Intranasal oxytocin produces anorectic effects on snack intake in men when tested in the absence of deprivation-induced hunger, but its effects on food intake in women without eating disorders have not been reported. Oxytocin may reduce food intake by reducing stress eating, since it inhibits ACTH release. The present study adopted a double-blind, repeated measures and fully concealed crossover protocol in which 38 women self-administered 24 IU of oxytocin or placebo intranasally, ate lunch, and underwent two consecutive stress tests. Snack intake was assessed 15-20 min after lunch, via a sham taste test. Salivary cortisol was measured throughout the test period every 15 min. Oxytocin significantly reduced sweet fatty snack intake independently of any effect on salivary cortisol, which declined over time at a similar rate after either drug or placebo. Ratings of sweet taste were slightly reduced by oxytocin, but only in self-reported stress eaters. These results differ from previous studies with men that found an effect of oxytocin on postprandial cortisol levels. However, previous research assayed the less active form of plasma cortisol and did not control for protein intake, which can drive elevated cortisol. The finding that oxytocin reduces snack intake in females after acute stress has important implications for appetite regulation and its treatment in obese people and in those with eating disorders.
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Affiliation(s)
- V Burmester
- Department of Psychology, School of Law, Social and Behavioural Sciences, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey KT1 2EE, UK
| | - E L Gibson
- Department of Psychology, Whitelands College, University of Roehampton, London SW15 4JD, UK
| | - G Butler
- Department of Psychology, School of Law, Social and Behavioural Sciences, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey KT1 2EE, UK
| | - A Bailey
- Institute of Medical and Biomedical Education, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK
| | - P Terry
- Department of Psychology, School of Law, Social and Behavioural Sciences, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey KT1 2EE, UK.
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Abstract
PURPOSE OF REVIEW The neurohypophysial endocrine system is identified here as a potential target for therapeutic interventions toward improving obesity-related metabolic dysfunction, given its coinciding pleiotropic effects on psychological, neurological and metabolic systems that are disrupted in obesity. RECENT FINDINGS Copeptin, the C-terminal portion of the precursor of arginine-vasopressin, is positively associated with body mass index and risk of type 2 diabetes. Plasma oxytocin is decreased in obesity and several other conditions of abnormal glucose homeostasis. Recent data also show non-classical tissues, such as myocytes, hepatocytes and β-cells, exhibit responses to oxytocin and vasopressin receptor binding that may contribute to alterations in metabolic function. The modulation of anorexigenic and orexigenic pathways appears to be the dominant mechanism underlying the effects of oxytocin and vasopressin on body weight regulation; however, there are apparent limitations associated with their use in direct pharmacological applications. A clearer picture of their wider physiological effects is needed before either system can be considered for therapeutic use.
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Affiliation(s)
| | - Faidon Magkos
- Department of Nutrition, Exercise and Sports-Section of Obesity Research, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C; Building 2-85, Room H134, Copenhagen, Denmark.
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Snider B, Geiser A, Yu XP, Beebe EC, Willency JA, Qing K, Guo L, Lu J, Wang X, Yang Q, Efanov A, Adams AC, Coskun T, Emmerson PJ, Alsina-Fernandez J, Ai M. Long-Acting and Selective Oxytocin Peptide Analogs Show Antidiabetic and Antiobesity Effects in Male Mice. J Endocr Soc 2019; 3:1423-1444. [PMID: 31286109 PMCID: PMC6608564 DOI: 10.1210/js.2019-00004] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 05/10/2019] [Indexed: 12/29/2022] Open
Abstract
Oxytocin (OXT) has been shown to suppress appetite, induce weight loss, and improve glycemic control and lipid metabolism in several species, including humans, monkeys, and rodents. However, OXT's short half-life in circulation and lack of receptor selectivity limit its application and efficacy. In this study, we report an OXT peptide analog (OXTGly) that is potent and selective for the OXT receptor (OXTR). OXT, but not OXTGly, activated vasopressin receptors in vitro and acutely increased blood pressure in vivo when administered IP. OXT suppressed food intake in mice, whereas OXTGly had a moderate effect on food intake when administered IP or intracerebroventricularly. Both OXT (IP) and OXTGly (IP) improved glycemic control in glucose tolerance tests. Additionally, both OXT (IP) and OXTGly (IP) stimulated insulin, glucagon-like peptide 1, and glucagon secretion in mice. We generated lipid-conjugated OXT (acylated-OXT) and OXTGly (acylated-OXTGly) and demonstrated that these molecules have significantly extended half-lives in vivo. Compared with OXT, 2-week treatment of diet-induced obese mice with acylated-OXT [subcutaneous(ly) (SC)] resulted in enhanced body weight reduction, an improved lipid profile, and gene expression changes consistent with increased lipolysis and decreased gluconeogenesis. Treatment with acylated-OXTGly (SC) also resulted in a statistically significant weight loss, albeit to a lesser degree compared with acylated-OXT treatment. In conclusion, we demonstrate that selective activation of the OXTR pathway results in both acute and chronic metabolic benefits, whereas potential activation of vasopressin receptors by nonselective OXT analogs causes physiological stress that contributes to additional weight loss.
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Affiliation(s)
- Brandy Snider
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Andrea Geiser
- Biotechnology Peptide Group, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Xiao-peng Yu
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Emily Cathleen Beebe
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Jill Amanda Willency
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Keyun Qing
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Lili Guo
- Biotechnology Peptide Group, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Jianliang Lu
- Medicinal Chemistry, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Xiaojun Wang
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Qian Yang
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Alexander Efanov
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Andrew Charles Adams
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Tamer Coskun
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Paul Joseph Emmerson
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Jorge Alsina-Fernandez
- Biotechnology Peptide Group, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
| | - Minrong Ai
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana
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Aulinas A, Pulumo RL, Asanza E, Mancuso CJ, Slattery M, Tolley C, Plessow F, Thomas JJ, Eddy KT, Miller KK, Klibanski A, Misra M, Lawson EA. Endogenous Oxytocin Levels in Relation to Food Intake, Menstrual Phase, and Age in Females. J Clin Endocrinol Metab 2019; 104:1348-1356. [PMID: 30445502 PMCID: PMC6408871 DOI: 10.1210/jc.2018-02036] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 11/13/2018] [Indexed: 12/22/2022]
Abstract
CONTEXT Oxytocin regulates a range of physiological processes including eating behavior and oxytocin administration reduces caloric intake in males. There are few data on oxytocin and eating behavior in healthy females or on the response of endogenous oxytocin to food intake and its relationship to appetite in humans. OBJECTIVES To determine the postprandial pattern of oxytocin levels, the relationship between oxytocin and appetite, and the impact of menstrual cycle phase and age on oxytocin levels in females. DESIGN Cross-sectional. SETTING Clinical research center. PARTICIPANTS Fifty-five healthy females (age 10 to 45 years). INTERVENTIONS A standardized mixed meal was administered. MAIN OUTCOME MEASUREMENTS Blood sampling for oxytocin occurred at fasting and at 30, 60, and 120 minutes postmeal. Appetite was assessed using Visual Analogue Scales pre- and postmeal. RESULTS Mean fasting oxytocin levels were 1011.2 ± 52.3 pg/mL (SEM) and decreased at 30 and 60 minutes postmeal (P = 0.001 and P = 0.003, respectively). Mean oxytocin levels decreased19.6% ± 3.0% from baseline to nadir. Oxytocin area under the curve was lower in the early to midfollicular menstrual cycle phase (P = 0.0003) and higher in younger females (P = 0.002). The percent change in oxytocin (baseline to nadir) was associated with postprandial hunger (rs = -0.291, P = 0.03) and fullness (rs = 0.345, P = 0.009). These relations remained significant after controlling for calories consumed, menstrual cycle status, and age (P = 0.023 and P = 0.0001, respectively). CONCLUSIONS Peripheral oxytocin levels in females decrease after a mixed meal and are associated with appetite independent of menstrual phase, age, and caloric intake, suggesting that endogenous oxytocin levels may play a role in perceived hunger and satiety.
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Affiliation(s)
- Anna Aulinas
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
| | | | - Elisa Asanza
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
| | | | - Meghan Slattery
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
| | - Christiane Tolley
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
| | - Franziska Plessow
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
| | - Jennifer J Thomas
- Harvard Medical School, Boston Massachusetts
- Eating Disorders Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston Massachusetts
| | - Kamryn T Eddy
- Harvard Medical School, Boston Massachusetts
- Eating Disorders Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital, Boston Massachusetts
| | - Karen K Miller
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
| | - Anne Klibanski
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
| | - Madhusmita Misra
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
- Pediatric Endocrine Unit, Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts
| | - Elizabeth A Lawson
- Neuroendocrine Unit, Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School, Boston Massachusetts
- Correspondence and Reprint Requests: Elizabeth A. Lawson, MD, MMSc, Neuroendocrine Unit, Massachusetts General Hospital, 55 Fruit Street, Boston, Massachusetts 02114. E-mail:
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Abstract
Oxytocin neurones in the hypothalamus are activated by stressful stimuli and food intake. The oxytocin receptor is located in various brain regions, including the sensory information-processing cerebral cortex; the cognitive information-processing prefrontal cortex; reward-related regions such as the ventral tegmental areas, nucleus accumbens and raphe nucleus; stress-related areas such as the amygdala, hippocampus, ventrolateral part of the ventromedial hypothalamus and ventrolateral periaqueductal gray; homeostasis-controlling hypothalamus; and the dorsal motor complex controlling intestinal functions. Oxytocin affects behavioural and neuroendocrine stress responses and terminates food intake by acting on the metabolic or nutritional homeostasis system, modulating emotional processing, reducing reward values of food intake, and facilitating sensory and cognitive processing via multiple brain regions. Oxytocin also plays a role in interactive actions between stress and food intake and contributes to adaptive active coping behaviours.
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Affiliation(s)
- Tatsushi Onaka
- Division of Brain and NeurophysiologyDepartment of PhysiologyJichi Medical UniversityShimotsuke‐shiJapan
| | - Yuki Takayanagi
- Division of Brain and NeurophysiologyDepartment of PhysiologyJichi Medical UniversityShimotsuke‐shiJapan
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42
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Klockars OA, Klockars A, Levine AS, Olszewski PK. Oxytocin administration in the basolateral and central nuclei of amygdala moderately suppresses food intake. Neuroreport 2018; 29:504-10. [PMID: 29538098 DOI: 10.1097/WNR.0000000000001005] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Oxytocin (OT) at acting central nuclei decreases meal size and reduces intake of palatable sweet solutions. It remains largely unclear as to which brain sites mediate OT's effect on palatability versus energy or the combination of those aspects of consumption. Here, we expanded the search for sites that mediate anorexigenic properties of OT by focusing on two subdivisions of the amygdala, its central (CNA) and basolateral (BLA) nuclei. We injected OT directly into the BLA or CNA in rats and assessed intake of standard chow induced by energy deprivation and intake of sweet solutions in nondeprived animals. We examined whether these effects are reversible by OT receptor (OTr) antagonism and whether OT presence in BLA or CNA induces taste aversion. We also determined the effect of energy deprivation and exposure to sweet saccharin on BLA and CNA expression of OTr mRNA. OT administration in BLA at 0.3 μg and in CNA at 1 μg reduced standard chow intake after deprivation by ~25%. Only administration of OT in BLA was effective in suppressing consumption of sucrose and saccharin solutions. The anorexigenic effects of OT in BLA and CNA were attenuated by OTr antagonist, L-368,899, pretreatment. OT at anorexigenic doses did not promote acquisition of taste aversion. BLA OTr mRNA expression was affected by exposure to palatable saccharin, whereas that of CNA OTr, by energy deprivation. OT in the amygdala moderately decreases food intake. The functional relationship between amygdalar OT and energy intake versus palatability-driven intake depends on the discrete localization of the OTr within this complex structure.
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43
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Skinner JA, Campbell EJ, Dayas CV, Garg ML, Burrows TL. The relationship between oxytocin, dietary intake and feeding: A systematic review and meta-analysis of studies in mice and rats. Front Neuroendocrinol 2019; 52:65-78. [PMID: 30315826 DOI: 10.1016/j.yfrne.2018.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 09/13/2018] [Accepted: 09/28/2018] [Indexed: 01/11/2023]
Abstract
The neuropeptide oxytocin has been associated with food intake and feeding behaviour. This systematic review aimed to investigate the impact of oxytocin on dietary intake and feeding behaviour in rodent studies. Six electronic databases were searched to identify published studies to April 2018. Preclinical studies in mice and rats were included if they reported: (1) a dietary measure (i.e. food or nutrient and/or behaviour (2) an oxytocin measure, and (3) relationship between the two measures. A total of 75 articles (n = 246 experiments) were included, and study quality appraised. The majority of studies were carried out in males (87%). The top three oxytocin outcomes assessed were: exogenous oxytocin administration (n = 126), oxytocin-receptor antagonist administration (n = 46) and oxytocin gene deletion (n = 29). Meta-analysis of exogenous studies in mice (3 studies, n = 43 comparisons) and rats (n = 8 studies, n = 82 comparisons) showed an overall decrease in food intake with maximum effect shown at 2 h post-administration.
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Affiliation(s)
- Janelle A Skinner
- Nutrition and Dietetics, School of Health Sciences, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia; Priority Research Centre for Physical Activity and Nutrition, University of Newcastle, Callaghan, NSW 2308, Australia.
| | - Erin J Campbell
- The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052, Australia; Florey Department of Neuroscience and Mental Health, University of Melbourne, Victoria 3010, Australia.
| | - Christopher V Dayas
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia.
| | - Manohar L Garg
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia.
| | - Tracy L Burrows
- Nutrition and Dietetics, School of Health Sciences, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia; Priority Research Centre for Physical Activity and Nutrition, University of Newcastle, Callaghan, NSW 2308, Australia.
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44
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Matsui S, Sasaki T, Kohno D, Yaku K, Inutsuka A, Yokota-Hashimoto H, Kikuchi O, Suga T, Kobayashi M, Yamanaka A, Harada A, Nakagawa T, Onaka T, Kitamura T. Neuronal SIRT1 regulates macronutrient-based diet selection through FGF21 and oxytocin signalling in mice. Nat Commun 2018; 9:4604. [PMID: 30389922 PMCID: PMC6214990 DOI: 10.1038/s41467-018-07033-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 10/12/2018] [Indexed: 12/02/2022] Open
Abstract
Diet affects health through ingested calories and macronutrients, and macronutrient balance affects health span. The mechanisms regulating macronutrient-based diet choices are poorly understood. Previous studies had shown that NAD-dependent deacetylase sirtuin-1 (SIRT1) in part influences the health-promoting effects of caloric restriction by boosting fat use in peripheral tissues. Here, we show that neuronal SIRT1 shifts diet choice from sucrose to fat in mice, matching the peripheral metabolic shift. SIRT1-mediated suppression of simple sugar preference requires oxytocin signalling, and SIRT1 in oxytocin neurons drives this effect. The hepatokine FGF21 acts as an endocrine signal to oxytocin neurons, promoting neuronal activation and Oxt transcription and suppressing the simple sugar preference. SIRT1 promotes FGF21 signalling in oxytocin neurons and stimulates Oxt transcription through NRF2. Thus, neuronal SIRT1 contributes to the homeostatic regulation of macronutrient-based diet selection in mice.
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Affiliation(s)
- Sho Matsui
- Laboratory of Metabolic Signal, Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8512, Japan
| | - Tsutomu Sasaki
- Laboratory of Metabolic Signal, Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8512, Japan.
| | - Daisuke Kohno
- Laboratory of Metabolic Signal, Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8512, Japan
- Advanced Scientific Research Leaders Development Unit, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8512, Japan
| | - Keisuke Yaku
- Frontier Research Core for Life Science, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan
- Department of Metabolism and Nutrition, Graduate School of Medicine and Pharmaceutical Science for Research, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan
| | - Ayumu Inutsuka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Furocho, Nagoya, 464-8601, Japan
- Division of Brain and Neurophysiology, Department of Physiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan
| | - Hiromi Yokota-Hashimoto
- Laboratory of Metabolic Signal, Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8512, Japan
| | - Osamu Kikuchi
- Laboratory of Metabolic Signal, Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8512, Japan
| | - Takayoshi Suga
- Laboratory of Metabolic Signal, Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8512, Japan
| | - Masaki Kobayashi
- Laboratory of Metabolic Signal, Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8512, Japan
| | - Akihiro Yamanaka
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Furocho, Nagoya, 464-8601, Japan
| | - Akihiro Harada
- Department of Cell Biology, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Takashi Nakagawa
- Frontier Research Core for Life Science, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan
- Department of Metabolism and Nutrition, Graduate School of Medicine and Pharmaceutical Science for Research, University of Toyama, 2630 Sugitani, Toyama, Toyama, 930-0194, Japan
| | - Tatsushi Onaka
- Division of Brain and Neurophysiology, Department of Physiology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan
| | - Tadahiro Kitamura
- Laboratory of Metabolic Signal, Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8512, Japan.
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Abstract
PURPOSE OF REVIEW The neurohormone oxytocin (OXT) impacts food intake as well as cognitive, emotional, and social functioning-all of which are central to eating disorder (ED) pathology across the weight spectrum. Here, we review findings on endogenous OXT levels and their relationship to ED pathology, the impact of exogenous OXT on mechanisms that drive ED presentation and chronicity, and the potential role of genetic predispositions in the OXT-ED link. RECENT FINDINGS Current findings suggest a role of the OXT system in the pathophysiology of anorexia nervosa. In individuals with bulimia nervosa, endogenous OXT levels were comparable to those of healthy controls, and exogenous OXT reduced food intake. Studies in other ED are lacking. However, genetic studies suggest a broad role of the OXT system in influencing ED pathology. Highlighting findings on why OXT represents a potential biomarker of and treatment target for ED, we advocate for a systematic research approach spanning the entire ED spectrum.
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46
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Grinevich V, Stoop R. Interplay between Oxytocin and Sensory Systems in the Orchestration of Socio-Emotional Behaviors. Neuron 2018; 99:887-904. [DOI: 10.1016/j.neuron.2018.07.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 07/02/2018] [Accepted: 07/10/2018] [Indexed: 01/01/2023]
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47
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Borland JM, Grantham KN, Aiani LM, Frantz KJ, Albers HE. Role of oxytocin in the ventral tegmental area in social reinforcement. Psychoneuroendocrinology 2018; 95:128-137. [PMID: 29852406 PMCID: PMC6109598 DOI: 10.1016/j.psyneuen.2018.05.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/20/2018] [Accepted: 05/20/2018] [Indexed: 01/08/2023]
Abstract
The rewarding properties of social interactions play a critical role in the development and maintenance of social relationships, and deficits in social reward are associated with various psychiatric disorders. In the present study, we used a novel Operant Social Preference (OSP) task to investigate the reinforcing properties of social interactions under conditions of high or low reward value, and high or low behavioral effort in male Syrian hamsters. Further, we investigated the role of oxytocin (OT) in a key structure of the mesolimbic reward system, the ventral tegmental area (VTA), in mediating the reinforcing properties of social interaction. Adult male hamsters were placed in a three-chambered apparatus, and allowed access to either a social chamber containing an unrestrained conspecific or a non-social chamber, by pushing through a one-way entry, vertical-swing door. Increasing the duration of social interaction (reward value) decreased the frequency of entering the social interaction chambers, whereas decreasing the duration of social interaction conversely increased the frequency of entries. Moreover, increasing behavioral effort required to access social interaction decreased the frequency of entries, especially under conditions when the duration of social interaction was only 5 s. OT injected into the VTA decreased the frequency of entering social interaction chambers in a manner similar to that observed when duration was increased, whereas injection of an OT receptor antagonist in the VTA increased the frequency of seeking social interaction. Taken together, these data support the hypothesis that activation of OT receptors in the VTA are critical for the reinforcing properties of social interactions. Furthermore, social interactions may exhibit duration and cost dependent reinforcing effects on behavior similar to those observed with food and drugs of abuse.
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Seelke AM, Rhine MA, Khun K, Shweyk AN, Scott AM, Bond JM, Graham JL, Havel PJ, Wolden-Hanson T, Bales KL, Blevins JE. Intranasal oxytocin reduces weight gain in diet-induced obese prairie voles. Physiol Behav 2018; 196:67-77. [PMID: 30144467 DOI: 10.1016/j.physbeh.2018.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 08/17/2018] [Accepted: 08/19/2018] [Indexed: 12/17/2022]
Abstract
Oxytocin (OT) elicits weight loss in diet-induced obese (DIO) rodents, nonhuman primates and humans by reducing food intake and increasing energy expenditure. In addition to being important in the regulation of energy balance, OT is involved in social behaviors including parent-infant bonds, friendships, and pair bonds. However, the impact of social context on susceptibility to diet-induced obesity (DIO) and feeding behavior (including food sharing) has not been investigated in a rodent model that forms strong social bonds (i.e. prairie vole). Our goals were to determine in Prairie voles (Microtus ochrogaster) whether i) social context impacts susceptibility to DIO and ii) chronic intranasal OT reverses DIO. Voles were housed in divided cages with holes in the divider and paired with a same-sex animal with either the same food [high fat diet (HFD)/HFD, [low fat diet (LFD; chow)/chow], or the opposite food (HFD/chow or chow/HFD) for 19 weeks. HFD-fed voles pair-housed with voles maintained on the HFD demonstrated increased weight relative to pair-housed voles that were both maintained on chow. The study was repeated to determine the impact of social context on DIO susceptibility and body composition when animals are maintained on purified sugar-sweetened HFD and LFD to enhance palatability. As before, we found that voles demonstrated higher weight gain on the HFD/HFD housing paradigm, in part, through increased energy intake and the weight gain was a consequence of an increase in fat mass. However, HFD-fed animals housed with LFD-fed animals (and vice versa) showed intermediate patterns of weight gain and evidence of food sharing. Of translational importance is the finding that chronic intranasal OT appeared to reduce weight gain in DIO voles through a decrease in fat mass with no reduction in lean body mass. These effects were associated with transient reductions in food intake and increased food sharing. These findings identify a role of social context in the pathogenesis of DIO and indicate that chronic intranasal OT treatment reduces weight gain and body fat mass in DIO prairie voles, in part, by reducing food intake.
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Affiliation(s)
- Adele M Seelke
- Department of Psychology, University of California, Davis, CA, USA
| | - Maya A Rhine
- Department of Psychology, University of California, Davis, CA, USA
| | - Konterri Khun
- Department of Psychology, University of California, Davis, CA, USA
| | - Amira N Shweyk
- Department of Psychology, University of California, Davis, CA, USA
| | | | - Jessica M Bond
- Department of Psychology, University of California, Davis, CA, USA
| | - James L Graham
- Department of Nutrition and Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Peter J Havel
- Department of Nutrition and Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Tami Wolden-Hanson
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA
| | - Karen L Bales
- Department of Psychology, University of California, Davis, CA, USA
| | - James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.
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Burmester V, Higgs S, Terry P. Rapid-onset anorectic effects of intranasal oxytocin in young men. Appetite 2018; 130:104-109. [PMID: 30081055 DOI: 10.1016/j.appet.2018.08.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 08/02/2018] [Accepted: 08/02/2018] [Indexed: 11/19/2022]
Abstract
Although the neuropeptide oxytocin exhibits many of the characteristics that would support its use as an anorectic agent for overeaters, studies of oxytocin's effectiveness at reducing eating in humans remain limited. In a double-blind, placebo-controlled crossover study, under the pretext of examining oxytocin's effects on various aspects of sensory perception, 20 men were given 24 IU of oxytocin and took a taste test of sweet, salty, and neutral snacks 45 min later. Participants self-rated appetite, anxiety, and other mood parameters, and then were left alone for 10 min with the pre-weighed snack food and invited to help themselves. To minimize the influence of hunger-driven eating, lunch had been provided immediately after oxytocin administration. In line with Ott et al. (2013), oxytocin significantly reduced the consumption of sweet foods; however, it also reduced consumption of salty snacks. Self-reported anxiety did not differ across drug conditions. The study is the first to demonstrate an effect of oxytocin on snack eating at 45 min post administration and on salty snacks. The anorectic efficacy of oxytocin after 45 min cannot easily be explained by the same mechanism as the one presumed to underpin its effects in previous studies that adopted much longer intervals between drug administration and testing.
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Affiliation(s)
- Victoria Burmester
- Department of Psychology, Kingston University, Penrhyn Road, Kingston-upon-Thames, Surrey, KT1 2EE, United Kingdom
| | - Suzanne Higgs
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Philip Terry
- Department of Psychology, Kingston University, Penrhyn Road, Kingston-upon-Thames, Surrey, KT1 2EE, United Kingdom.
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Freeman SM, Ngo J, Singh B, Masnaghetti M, Bales KL, Blevins JE. Effects of Chronic Oxytocin Administration and Diet Composition on Oxytocin and Vasopressin 1a Receptor Binding in the Rat Brain. Neuroscience 2018; 392:241-251. [PMID: 30071278 DOI: 10.1016/j.neuroscience.2018.07.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 12/19/2022]
Abstract
Oxytocin (OT) elicits weight loss in diet-induced obese (DIO) rodents, nonhuman primates, and humans, in part, by reducing food intake. Chronic OT administration produces more sustained weight loss in high-fat diet (HFD)-fed DIO rodents relative to chow-fed controls, but the reasons for this effect remain unclear. We hypothesized that HFD-induced obesity is associated with elevated OT receptor (OXTR) binding in brain regions where OT is known to cause decreased food intake and that this sensitized neural system is one mechanism by which OT preferentially elicits weight loss in DIO rodents. We therefore determined the impact of diet (HFD vs chow) and drug treatment (chronic OT infusion vs vehicle) on (1) OXTR binding in hindbrain and forebrain sites where OT suppresses food intake relative to control sites that express OXTR and (2) forebrain vasopressin 1a receptor (AVPR1a) density to evaluate the specificity of any OT effects. Using quantitative receptor autoradiography, we found that (1) diet composition failed to alter OXTR or AVPR1a binding; (2) chronic OT treatment produced largely global reductions in forebrain OXTR and AVPR1a binding without significantly altering hindbrain OXTR binding. These findings suggest that forebrain OXTR and AVPR1a are down-regulated in response to chronic OT treatment. Given that chronic intranasal OT may be used as a therapeutic strategy to treat obesity, future studies should consider the potential downregulatory effect that chronic treatment can have across forebrain and hindbrain nonapeptide receptors and assess the potential contribution of both receptor subtypes to the outcome measures.
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Affiliation(s)
- Sara M Freeman
- Department of Psychology, University of California, Davis, CA, USA
| | - Julie Ngo
- Department of Psychology, University of California, Davis, CA, USA
| | - Bhavdeep Singh
- Department of Psychology, University of California, Davis, CA, USA
| | | | - Karen L Bales
- Department of Psychology, University of California, Davis, CA, USA
| | - James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Seattle, WA 98108, USA; Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.
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