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Geisler CE, Hayes MR. Metabolic Hormone Action in the VTA: Reward-Directed Behavior and Mechanistic Insights. Physiol Behav 2023; 268:114236. [PMID: 37178855 DOI: 10.1016/j.physbeh.2023.114236] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 04/10/2023] [Accepted: 05/10/2023] [Indexed: 05/15/2023]
Abstract
Dysfunctional signaling in midbrain reward circuits perpetuates diseases characterized by compulsive overconsumption of rewarding substances such as substance abuse, binge eating disorder, and obesity. Ventral tegmental area (VTA) dopaminergic activity serves as an index for how rewarding stimuli are perceived and triggers behaviors necessary to obtain future rewards. The evolutionary linking of reward with seeking and consuming palatable foods ensured an organism's survival, and hormone systems that regulate appetite concomitantly developed to regulate motivated behaviors. Today, these same mechanisms serve to regulate reward-directed behavior around food, drugs, alcohol, and social interactions. Understanding how hormonal regulation of VTA dopaminergic output alters motivated behaviors is essential to leveraging therapeutics that target these hormone systems to treat addiction and disordered eating. This review will outline our current understanding of the mechanisms underlying VTA action of the metabolic hormones ghrelin, glucagon-like peptide-1, amylin, leptin, and insulin to regulate behavior around food and drugs of abuse, highlighting commonalities and differences in how these five hormones ultimately modulate VTA dopamine signaling.
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Affiliation(s)
- Caroline E Geisler
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Matthew R Hayes
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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2
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de Vrind VAJ, van ‘t Sant LJ, Rozeboom A, Luijendijk-Berg MCM, Omrani A, Adan RAH. Leptin Receptor Expressing Neurons in the Substantia Nigra Regulate Locomotion, and in The Ventral Tegmental Area Motivation and Feeding. Front Endocrinol (Lausanne) 2021; 12:680494. [PMID: 34276560 PMCID: PMC8281287 DOI: 10.3389/fendo.2021.680494] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 06/10/2021] [Indexed: 11/13/2022] Open
Abstract
Leptin is an anorexigenic hormone, important in the regulation of body weight. Leptin plays a role in food reward, feeding, locomotion and anxiety. Leptin receptors (LepR) are expressed in many brain areas, including the midbrain. In most studies that target the midbrain, either all LepR neurons of the midbrain or those of the ventral tegmental area (VTA) were targeted, but the role of substantia nigra (SN) LepR neurons has not been investigated. These studies have reported contradicting results regarding motivational behavior for food reward, feeding and locomotion. Since not all midbrain LepR mediated behaviors can be explained by LepR neurons in the VTA alone, we hypothesized that SN LepR neurons may provide further insight. We first characterized SN LepR and VTA LepR expression, which revealed LepR expression mainly on DA neurons. To further understand the role of midbrain LepR neurons in body weight regulation, we chemogenetically activated VTA LepR or SN LepR neurons in LepR-cre mice and tested for motivational behavior, feeding and locomotion. Activation of VTA LepR neurons in food restricted mice decreased motivation for food reward (p=0.032) and food intake (p=0.020), but not locomotion. In contrast, activation of SN LepR neurons in food restricted mice decreased locomotion (p=0.025), but not motivation for food reward or food intake. Our results provide evidence that VTA LepR and SN LepR neurons serve different functions, i.e. activation of VTA LepR neurons modulated motivation for food reward and feeding, while SN LepR neurons modulated locomotor activity.
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Affiliation(s)
- Véronne A. J. de Vrind
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht and University Utrecht, Utrecht, Netherlands
| | - Lisanne J. van ‘t Sant
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht and University Utrecht, Utrecht, Netherlands
| | - Annemieke Rozeboom
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht and University Utrecht, Utrecht, Netherlands
| | - Mieneke C. M. Luijendijk-Berg
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht and University Utrecht, Utrecht, Netherlands
| | - Azar Omrani
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht and University Utrecht, Utrecht, Netherlands
| | - Roger A. H. Adan
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht and University Utrecht, Utrecht, Netherlands
- Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- *Correspondence: Roger A. H. Adan,
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The Novel Perspectives of Adipokines on Brain Health. Int J Mol Sci 2019; 20:ijms20225638. [PMID: 31718027 PMCID: PMC6887733 DOI: 10.3390/ijms20225638] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 11/05/2019] [Accepted: 11/06/2019] [Indexed: 12/13/2022] Open
Abstract
First seen as a fat-storage tissue, the adipose tissue is considered as a critical player in the endocrine system. Precisely, adipose tissue can produce an array of bioactive factors, including cytokines, lipids, and extracellular vesicles, which target various systemic organ systems to regulate metabolism, homeostasis, and immune response. The global effects of adipokines on metabolic events are well defined, but their impacts on brain function and pathology remain poorly defined. Receptors of adipokines are widely expressed in the brain. Mounting evidence has shown that leptin and adiponectin can cross the blood–brain barrier, while evidence for newly identified adipokines is limited. Significantly, adipocyte secretion is liable to nutritional and metabolic states, where defective circuitry, impaired neuroplasticity, and elevated neuroinflammation are symptomatic. Essentially, neurotrophic and anti-inflammatory properties of adipokines underlie their neuroprotective roles in neurodegenerative diseases. Besides, adipocyte-secreted lipids in the bloodstream can act endocrine on the distant organs. In this article, we have reviewed five adipokines (leptin, adiponectin, chemerin, apelin, visfatin) and two lipokines (palmitoleic acid and lysophosphatidic acid) on their roles involving in eating behavior, neurotrophic and neuroprotective factors in the brain. Understanding and regulating these adipokines can lead to novel therapeutic strategies to counteract metabolic associated eating disorders and neurodegenerative diseases, thus promote brain health.
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Rebolledo-Solleiro D, Roldán-Roldán G, Díaz D, Velasco M, Larqué C, Rico-Rosillo G, Vega-Robledo GB, Zambrano E, Hiriart M, Pérez de la Mora M. Increased anxiety-like behavior is associated with the metabolic syndrome in non-stressed rats. PLoS One 2017; 12:e0176554. [PMID: 28463967 PMCID: PMC5413000 DOI: 10.1371/journal.pone.0176554] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 04/12/2017] [Indexed: 01/08/2023] Open
Abstract
Metabolic syndrome (MS) is a cluster of signs that increases the risk to develop diabetes mellitus type 2 and cardiovascular disease. In the last years, a growing interest to study the relationship between MS and psychiatric disorders, such as depression and anxiety, has emerged obtaining conflicting results. Diet-induced MS rat models have only examined the effects of high-fat or mixed cafeteria diets to a limited extent. We explored whether an anxiety-like behavior was associated with MS in non-stressed rats chronically submitted to a high-sucrose diet (20% sucrose in drinking water) using three different anxiety paradigms: the shock-probe/burying test (SPBT), the elevated plus-maze (EPM) and the open-field test (OFT). Behaviorally, the high-sucrose diet group showed an increase in burying behavior in the SPBT. Also, these animals displayed both avoidance to explore the central part of the arena and a significant increase in freezing behavior in the OFT and lack of effects in the EPM. Also, high-sucrose diet group showed signs of an MS-like condition: significant increases in body weight and body mass index, abdominal obesity, hypertension, hyperglycemia, hyperinsulinemia, and dyslipidemia. Plasma leptin and resistin levels were also increased. No changes in plasma corticosterone levels were found. These results indicate that rats under a 24-weeks high-sucrose diet develop an MS associated with an anxiety-like behavior. Although the mechanisms underlying this behavioral outcome remain to be investigated, the role of leptin is emphasized.
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Affiliation(s)
- Daniela Rebolledo-Solleiro
- Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional, Autónoma de México, Mexico City, Mexico
- * E-mail: (MPM); (DR-S)
| | - Gabriel Roldán-Roldán
- Laboratorio de Neurobiología de la Conducta, Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Daniel Díaz
- Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Myrian Velasco
- Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional, Autónoma de México, Mexico City, Mexico
| | - Carlos Larqué
- Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional, Autónoma de México, Mexico City, Mexico
| | - Guadalupe Rico-Rosillo
- Laboratorio de Inmunología, Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Gloria Bertha Vega-Robledo
- Laboratorio de Inmunología, Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Elena Zambrano
- Departamento de Biología de la Reproducción, Instituto Nacional de la Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Marcia Hiriart
- Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional, Autónoma de México, Mexico City, Mexico
| | - Miguel Pérez de la Mora
- Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional, Autónoma de México, Mexico City, Mexico
- * E-mail: (MPM); (DR-S)
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Desensitization of leptin receptors is coincident with the upregulation of dopamine-related genes in the prefrontal cortex of adolescent mice. Neuroreport 2016; 27:516-21. [DOI: 10.1097/wnr.0000000000000574] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Leptin resistance in obesity: An epigenetic landscape. Life Sci 2015; 140:57-63. [PMID: 25998029 DOI: 10.1016/j.lfs.2015.05.003] [Citation(s) in RCA: 146] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 05/02/2015] [Accepted: 05/12/2015] [Indexed: 01/14/2023]
Abstract
Leptin is an adipocyte-secreted hormone that inhibits food intake and stimulates energy expenditure through interactions with neuronal pathways in the brain, particularly pathways involving the hypothalamus. Intact functioning of the leptin route is required for body weight and energy homeostasis. Given its function, the discovery of leptin increased expectations for the treatment of obesity. However, most obese individuals and subjects with a predisposition to regain weight after losing it have leptin concentrations than lean individuals, but despite the anorexigenic function of this hormone, appetite is not effectively suppressed in these individuals. This phenomenon has been deemed leptin resistance and could be the result of impairments at a number of levels in the leptin signalling pathway, including reduced access of the hormone to its receptor due to changes in receptor expression or changes in post-receptor signal transduction. Epigenetic regulation of the leptin signalling circuit could be a potential mechanism of leptin function disturbance. This review discusses the molecular mechanisms, particularly the epigenetic regulation mechanisms, involved in leptin resistance associated with obesity and the therapeutic potential of these molecular mechanisms in the battle against the obesity pandemic.
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Tulloch AJ, Murray S, Vaicekonyte R, Avena NM. Neural responses to macronutrients: hedonic and homeostatic mechanisms. Gastroenterology 2015; 148:1205-18. [PMID: 25644095 DOI: 10.1053/j.gastro.2014.12.058] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 12/16/2014] [Accepted: 12/22/2014] [Indexed: 01/15/2023]
Abstract
The brain responds to macronutrients via intricate mechanisms. We review how the brain's neural systems implicated in homeostatic control of feeding and hedonic responses are influenced by the ingestion of specific types of food. We discuss how these neural systems are dysregulated in preclinical models of obesity. Findings from these studies can increase our understanding of overeating and, perhaps in some cases, the development of obesity. In addition, a greater understanding of the neural circuits affected by the consumption of specific macronutrients, and by obesity, might lead to new treatments and strategies for preventing unhealthy weight gain.
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Affiliation(s)
- Alastair J Tulloch
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York
| | - Susan Murray
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York
| | - Regina Vaicekonyte
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York
| | - Nicole M Avena
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York.
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8
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Liu S, Borgland S. Regulation of the mesolimbic dopamine circuit by feeding peptides. Neuroscience 2015; 289:19-42. [DOI: 10.1016/j.neuroscience.2014.12.046] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 12/27/2014] [Accepted: 12/31/2014] [Indexed: 12/30/2022]
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Sáinz N, Barrenetxe J, Moreno-Aliaga MJ, Martínez JA. Leptin resistance and diet-induced obesity: central and peripheral actions of leptin. Metabolism 2015; 64:35-46. [PMID: 25497342 DOI: 10.1016/j.metabol.2014.10.015] [Citation(s) in RCA: 290] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 10/15/2014] [Accepted: 10/20/2014] [Indexed: 12/15/2022]
Abstract
Obesity is a chronic disease that represents one of the most serious global health burdens associated to an excess of body fat resulting from an imbalance between energy intake and expenditure, which is regulated by environmental and genetic interactions. The adipose-derived hormone leptin acts via a specific receptor in the brain to regulate energy balance and body weight, although this protein can also elicit a myriad of actions in peripheral tissues. Obese individuals, rather than be leptin deficient, have in most cases, high levels of circulating leptin. The failure of these high levels to control body weight suggests the presence of a resistance process to the hormone that could be partly responsible of disturbances on body weight regulation. Furthermore, leptin resistance can impair physiological peripheral functions of leptin such as lipid and carbohydrate metabolism and nutrient intestinal utilization. The present document summarizes those findings regarding leptin resistance development and the role of this hormone in the development and maintenance of an obese state. Thus, we focused on the effect of the impaired leptin action on adipose tissue, liver, skeletal muscle and intestinal function and the accompanying relationships with diet-induced obesity. The involvement of some inflammatory mediators implicated in the development of obesity and their roles in leptin resistance development are also discussed.
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Affiliation(s)
- Neira Sáinz
- Department of Nutrition, Food Sciences and Physiology, University of Navarra, C/Irunlarrea 1, 31008 Pamplona, Spain
| | - Jaione Barrenetxe
- Department of Nutrition, Food Sciences and Physiology, University of Navarra, C/Irunlarrea 1, 31008 Pamplona, Spain
| | - María J Moreno-Aliaga
- Department of Nutrition, Food Sciences and Physiology, University of Navarra, C/Irunlarrea 1, 31008 Pamplona, Spain; CIBER Fisiopatología de la Obesidad y la Nutrición (CIBERobn), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - José Alfredo Martínez
- Department of Nutrition, Food Sciences and Physiology, University of Navarra, C/Irunlarrea 1, 31008 Pamplona, Spain; CIBER Fisiopatología de la Obesidad y la Nutrición (CIBERobn), Instituto de Salud Carlos III, 28029 Madrid, Spain.
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10
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Murray S, Tulloch A, Gold MS, Avena NM. Hormonal and neural mechanisms of food reward, eating behaviour and obesity. Nat Rev Endocrinol 2014; 10:540-52. [PMID: 24958311 DOI: 10.1038/nrendo.2014.91] [Citation(s) in RCA: 143] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
With rising rates of obesity, research continues to explore the contributions of homeostatic and hedonic mechanisms related to eating behaviour. In this Review, we synthesize the existing information on select biological mechanisms associated with reward-related food intake, dealing primarily with consumption of highly palatable foods. In addition to their established functions in normal feeding, three primary peripheral hormones (leptin, ghrelin and insulin) play important parts in food reward. Studies in laboratory animals and humans also show relationships between hyperphagia or obesity and neural pathways involved in reward. These findings have prompted questions regarding the possibility of addictive-like aspects in food consumption. Further exploration of this topic may help to explain aberrant eating patterns, such as binge eating, and provide insight into the current rates of overweight and obesity.
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Affiliation(s)
- Susan Murray
- New York Obesity Research Center, Department of Medicine, Columbia University College of Physicians and Surgeons, P&S Box 30 DOM/NYORC, 630 West 168th Street, New York, NY 10032-3702, USA
| | - Alastair Tulloch
- New York Obesity Research Center, Department of Medicine, Columbia University College of Physicians and Surgeons, P&S Box 30 DOM/NYORC, 630 West 168th Street, New York, NY 10032-3702, USA
| | - Mark S Gold
- Department of Psychiatry, College of Medicine, University of Florida, McKnight Brain Institute, 1149 SW Newell Drive, L4-100, Gainesville, FL 32610, USA
| | - Nicole M Avena
- New York Obesity Research Center, Department of Medicine, Columbia University College of Physicians and Surgeons, P&S Box 30 DOM/NYORC, 630 West 168th Street, New York, NY 10032-3702, USA
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Matheny M, Strehler KYE, King M, Tümer N, Scarpace PJ. Targeted leptin receptor blockade: role of ventral tegmental area and nucleus of the solitary tract leptin receptors in body weight homeostasis. J Endocrinol 2014; 222:27-41. [PMID: 24920667 PMCID: PMC4066415 DOI: 10.1530/joe-13-0455] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The present investigation examined whether leptin stimulation of ventral tegmental area (VTA) or nucleus of the solitary tract (NTS) has a role in body weight homeostasis independent of the medial basal hypothalamus (MBH). To this end, recombinant adeno-associated viral techniques were employed to target leptin overexpression or overexpression of a dominant negative leptin mutant (leptin antagonist). Leptin antagonist overexpression in MBH or VTA increased food intake and body weight to similar extents over 14 days in rats. Simultaneous overexpression of leptin in VTA with antagonist in MBH resulted in food intake and body weight gain that were less than with control treatment but greater than with leptin alone in VTA. Notably, leptin overexpression in VTA increased P-STAT3 in MBH along with VTA, and leptin antagonist overexpression in the VTA partially attenuated P-STAT3 levels in MBH. Interestingly, leptin antagonist overexpression elevated body weight gain, but leptin overexpression in the NTS failed to modulate either food intake or body weight despite increased P-STAT3. These data suggest that leptin function in the VTA participates in the chronic regulation of food consumption and body weight in response to stimulation or blockade of VTA leptin receptors. Moreover, one component of VTA-leptin action appears to be independent of the MBH, and another component appears to be related to leptin receptor-mediated P-STAT3 activation in the MBH. Finally, leptin receptors in the NTS are necessary for normal energy homeostasis, but mostly they appear to have a permissive role. Direct leptin activation of NTS slightly increases UCP1 levels, but has little effect on food consumption or body weight.
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Affiliation(s)
- M Matheny
- Department of Pharmacology and TherapeuticsCollege of Medicine, University of Florida, PO Box 100267, Gainesville, Florida 32610, USADepartment of Veterans AffairsMedical Center, Gainesville, Florida 32608-1197, USA
| | - K Y E Strehler
- Department of Pharmacology and TherapeuticsCollege of Medicine, University of Florida, PO Box 100267, Gainesville, Florida 32610, USADepartment of Veterans AffairsMedical Center, Gainesville, Florida 32608-1197, USA
| | - M King
- Department of Pharmacology and TherapeuticsCollege of Medicine, University of Florida, PO Box 100267, Gainesville, Florida 32610, USADepartment of Veterans AffairsMedical Center, Gainesville, Florida 32608-1197, USADepartment of Pharmacology and TherapeuticsCollege of Medicine, University of Florida, PO Box 100267, Gainesville, Florida 32610, USADepartment of Veterans AffairsMedical Center, Gainesville, Florida 32608-1197, USA
| | - N Tümer
- Department of Pharmacology and TherapeuticsCollege of Medicine, University of Florida, PO Box 100267, Gainesville, Florida 32610, USADepartment of Veterans AffairsMedical Center, Gainesville, Florida 32608-1197, USADepartment of Pharmacology and TherapeuticsCollege of Medicine, University of Florida, PO Box 100267, Gainesville, Florida 32610, USADepartment of Veterans AffairsMedical Center, Gainesville, Florida 32608-1197, USA
| | - P J Scarpace
- Department of Pharmacology and TherapeuticsCollege of Medicine, University of Florida, PO Box 100267, Gainesville, Florida 32610, USADepartment of Veterans AffairsMedical Center, Gainesville, Florida 32608-1197, USA
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12
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van den Heuvel JK, Eggels L, Fliers E, Kalsbeek A, Adan RAH, la Fleur SE. Differential modulation of arcuate nucleus and mesolimbic gene expression levels by central leptin in rats on short-term high-fat high-sugar diet. PLoS One 2014; 9:e87729. [PMID: 24498181 PMCID: PMC3909349 DOI: 10.1371/journal.pone.0087729] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 12/28/2013] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVE Leptin resistance is a common hallmark of obesity. Rats on a free-choice high-fat high-sugar (fcHFHS) diet are resistant to peripherally administered leptin. The aim of this study was to investigate feeding responses to central leptin as well as the associated changes in mRNA levels in hypothalamic and mesolimbic brain areas. DESIGN AND METHODS Rats on a CHOW or fcHFHS diet for 8 days received leptin or vehicle intracerebro(lateral)ventricularly (ICV) and food intake was measured 5 h and 24 h later. Four days later, rats were sacrificed after ICV leptin or vehicle and mRNA levels were quantified for hypothalamic pro-opiomelanocortin (POMC) and neuropeptide Y (NPY) and for preproenkephalin (ppENK) in nucleus accumbens and tyrosine hydroxylase (TH) in ventral tegmental area (VTA). RESULTS ICV leptin decreased caloric intake both in CHOW and fcHFHS rats. In fcHFHS, leptin preferentially decreased chow and fat intake. Leptin increased POMC and decreased NPY mRNA in CHOW, but not in fcHFHS rats. In CHOW rats, leptin had no effect on ppENK mRNA and decreased TH mRNA. In fcHFHS, leptin decreased ppENK mRNA and increased TH mRNA. CONCLUSION Despite peripheral and arcuate leptin resistance, central leptin suppresses feeding in fcHFHS rats. As the VTA and nucleus accumbens are still responsive to leptin, these brain areas may therefore, at least partly, account for the leptin-induced feeding suppression in rats on a fcHFHS diet.
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Affiliation(s)
- José K. van den Heuvel
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Leslie Eggels
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Eric Fliers
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Andries Kalsbeek
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Hypothalamic Integration Mechanisms, Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - Roger A. H. Adan
- Rudolf Magnus Institute of Neuroscience, Department of Neuroscience and Pharmacology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Susanne E. la Fleur
- Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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