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Conn K, Huang K, Gorrell S, Foldi CJ. A transdiagnostic and translational framework for delineating the neuronal mechanisms of compulsive exercise in anorexia nervosa. Int J Eat Disord 2024; 57:1406-1417. [PMID: 38174745 PMCID: PMC11222308 DOI: 10.1002/eat.24130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 12/21/2023] [Accepted: 12/21/2023] [Indexed: 01/05/2024]
Abstract
OBJECTIVE The development of novel treatments for anorexia nervosa (AN) requires a detailed understanding of the biological underpinnings of specific, commonly occurring symptoms, including compulsive exercise. There is considerable bio-behavioral overlap between AN and obsessive-compulsive disorder (OCD), therefore it is plausible that similar mechanisms underlie compulsive behavior in both populations. While the association between these conditions is widely acknowledged, defining the shared mechanisms for compulsive behavior in AN and OCD requires a novel approach. METHODS We present an argument that a better understanding of the neurobiological mechanisms that underpin compulsive exercise in AN can be achieved in two critical ways. First, by applying a framework of the neuronal control of OCD to exercise behavior in AN, and second, by taking better advantage of the activity-based anorexia (ABA) rodent model to directly test this framework in the context of feeding pathology. RESULTS A cross-disciplinary approach that spans preclinical, neuroimaging, and clinical research as well as compulsive neurocircuitry and behavior can advance our understanding of when, why, and how compulsive exercise develops in the context of AN and provide targets for novel treatment strategies. DISCUSSION In this article, we (i) link the expression of compulsive behavior in AN and OCD via a transition between goal-directed and habitual behavior, (ii) present disrupted cortico-striatal circuitry as a key substrate for the development of compulsive behavior in both conditions, and (iii) highlight the utility of the ABA rodent model to better understand the mechanisms of compulsive behavior relevant to AN. PUBLIC SIGNIFICANCE Individuals with AN who exercise compulsively are at risk of worse health outcomes and have poorer responses to standard treatments. However, when, why, and how compulsive exercise develops in AN remains inadequately understood. Identifying whether the neural circuitry underlying compulsive behavior in OCD also controls hyperactivity in the activity-based anorexia model will aid in the development of novel eating disorder treatment strategies for this high-risk population.
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Affiliation(s)
- K Conn
- Monash University, Department of Physiology, 26 Innovation Walk, 3800, Clayton, Australia
- Monash Biomedicine Discovery Institute, 23 Innovation Walk, 3800, Clayton, Australia
| | - K Huang
- Monash University, Department of Physiology, 26 Innovation Walk, 3800, Clayton, Australia
- Monash Biomedicine Discovery Institute, 23 Innovation Walk, 3800, Clayton, Australia
| | - S Gorrell
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, 675 18th street, San Francisco, CA 94143, USA
| | - CJ Foldi
- Monash University, Department of Physiology, 26 Innovation Walk, 3800, Clayton, Australia
- Monash Biomedicine Discovery Institute, 23 Innovation Walk, 3800, Clayton, Australia
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2
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Giunti E, Collu R, Dedoni S, Castelli MP, Fratta W, Scherma M, Fadda P. Food restriction and hyperactivity induce changes in corticolimbic brain dopamine and serotonin levels in female rats. Behav Brain Res 2023; 444:114374. [PMID: 36863461 DOI: 10.1016/j.bbr.2023.114374] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/27/2023] [Accepted: 02/27/2023] [Indexed: 03/04/2023]
Abstract
Compelling data support altered dopamine (DA) and serotonin (5-HT) signaling in anorexia nervosa (AN). However, their exact role in the etiopathogenesis of AN has yet to be elucidated. Here, we evaluated the corticolimbic brain levels of DA and 5-HT in the induction and recovery phases of the activity-based anorexia (ABA) model of AN. We exposed female rats to the ABA paradigm and measured the levels of DA, 5-HT, the metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), and the dopaminergic type 2 (D2) receptors density in feeding- and reward-implicated brain regions (i.e., cerebral cortex, Cx; prefrontal cortex, PFC; caudate putamen, CPu; nucleus accumbens, NAcc; amygdala, Amy; hypothalamus, Hyp; hippocampus, Hipp). DA levels were significantly increased in the Cx, PFC and NAcc, while 5-HT was significantly enhanced in the NAcc and Hipp of ABA rats. Following recovery, DA was still elevated in the NAcc, while 5-HT was increased in the Hyp of recovered ABA rats. DA and 5-HT turnover were impaired at both ABA induction and recovery. D2 receptors density was increased in the NAcc shell. These results provide further proof of the impairment of the dopaminergic and serotoninergic systems in the brain of ABA rats and support the knowledge of the involvement of these two important neurotransmitter systems in the development and progression of AN. Thus, providing new insights on the corticolimbic regions involved in the monoamine dysregulations in the ABA model of AN.
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Affiliation(s)
- Elisa Giunti
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | - Roberto Collu
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | - Simona Dedoni
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | - M Paola Castelli
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy
| | | | - Maria Scherma
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy.
| | - Paola Fadda
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, University of Cagliari, Cagliari, Italy; CNR Institute of Neuroscience, Cagliari, National Research Council, Cagliari, Italy
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Keeler JL, Robinson L, Keeler-Schäffeler R, Dalton B, Treasure J, Himmerich H. Growth factors in anorexia nervosa: a systematic review and meta-analysis of cross-sectional and longitudinal data. World J Biol Psychiatry 2022; 23:582-600. [PMID: 34875968 DOI: 10.1080/15622975.2021.2015432] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVES Growth factors are signalling molecules that play roles in the survival, proliferation, migration, and differentiation of cells. Studies have found alterations in specific growth factors in anorexia nervosa (AN). METHODS This systematic review and meta-analysis examined articles from three databases, measuring growth factors in AN cross-sectionally and longitudinally, and in recovered AN (rec-AN) cross-sectionally. Random-effects meta-analyses were conducted for brain-derived neurotrophic factor (BDNF) and insulin growth factor-I (IGF-1) for cross-sectional and longitudinal studies. RESULTS A total of 82 studies were included: 56 cross-sectional (BDNF: n = 15; IGF-1: n = 41) and 24 longitudinal (BDNF: n = 5; IGF-1: n = 19) were meta-analysed and 20 studies were narratively synthesised. In cross-sectional analyses, BDNF and IGF-1 were lower in AN compared to controls, and BDNF was marginally greater in rec-AN compared to controls. In longitudinal meta-analyses, BDNF and IGF-1 increased from baseline to follow-up. Cross-sectional subgroup analyses revealed no differences in BDNF between controls and AN binge-eating/purging subtypes. CONCLUSIONS It is likely that the low BDNF and IGF-1 levels found in AN are consequences of starvation, which are reversible with weight restoration. The increase in BDNF and IGF-1 during therapeutic weight restoration might improve neuroplasticity, which is the basis of learning, and thus psychotherapeutic success.
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Affiliation(s)
- Johanna Louise Keeler
- Section of Eating Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Lauren Robinson
- Section of Eating Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | | | - Bethan Dalton
- Section of Eating Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Janet Treasure
- Section of Eating Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Hubertus Himmerich
- Section of Eating Disorders, Department of Psychological Medicine, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
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The BDNF Val66Met Polymorphism Does Not Increase Susceptibility to Activity-Based Anorexia in Rats. BIOLOGY 2022; 11:biology11050623. [PMID: 35625351 PMCID: PMC9138045 DOI: 10.3390/biology11050623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 04/13/2022] [Accepted: 04/17/2022] [Indexed: 11/18/2022]
Abstract
Simple Summary Genetic animal models are a valuable tool for understanding how human pathologies develop. The type of animal model chosen is important for uncovering effects specific to certain behaviours and neurobiological functions. A polymorphism in the brain-derived neurotrophic factor (BDNF) has been linked with various clinical conditions in human subjects and with mouse models of anorectic behaviour. This study investigated for the first time the role of the BDNF Val66Met allelic substitution in a rat model of anorexia nervosa (AN), known as activity-based anorexia (ABA). Contrary to reports of altered BDNF signaling in patients with AN and increased anorectic behaviour in a mouse model containing the same allelic variation, it showed that 66Met did not alter susceptibility to weight loss or aspects of energy balance, including feeding and exercise in the rat model. It highlights the need to consider species–specific differences when evaluating animal models of human pathologies. Abstract Brain-derived neurotrophic factor (BDNF) is abundantly expressed in brain regions involved in both homeostatic and hedonic feeding, and it circulates at reduced levels in patients with anorexia nervosa (AN). A single nucleotide polymorphism in the gene encoding for BDNF (Val66Met) has been associated with worse outcomes in patients with AN, and it is shown to promote anorectic behaviour in a mouse model of caloric restriction paired with social isolation stress. Previous animal models of the Val66Met polymorphism have been in mice because of the greater ease in modification of the mouse genome, however, the most widely-accepted animal model of AN, known as activity-based anorexia (ABA), is most commonly conducted in rats. Here, we examine ABA outcomes in a novel rat model of the BDNF Val66Met allelic variation (Val68Met), and we investigate the role of this polymorphism in feeding, food choice and sucrose preference, and energy expenditure. We demonstrate that the BDNF Val68Met polymorphism does not influence susceptibility to ABA or any aspect of feeding behaviour. The discrepancy between these results and previous reports in mice may relate to species–specific differences in stress reactivity.
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Beeler JA, Burghardt NS. The Rise and Fall of Dopamine: A Two-Stage Model of the Development and Entrenchment of Anorexia Nervosa. Front Psychiatry 2022; 12:799548. [PMID: 35087433 PMCID: PMC8787068 DOI: 10.3389/fpsyt.2021.799548] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 12/14/2021] [Indexed: 12/03/2022] Open
Abstract
Dopamine has long been implicated as a critical neural substrate mediating anorexia nervosa (AN). Despite nearly 50 years of research, the putative direction of change in dopamine function remains unclear and no consensus on the mechanistic role of dopamine in AN has been achieved. We hypothesize two stages in AN- corresponding to initial development and entrenchment- characterized by opposite changes in dopamine. First, caloric restriction, particularly when combined with exercise, triggers an escalating spiral of increasing dopamine that facilitates the behavioral plasticity necessary to establish and reinforce weight-loss behaviors. Second, chronic self-starvation reverses this escalation to reduce or impair dopamine which, in turn, confers behavioral inflexibility and entrenchment of now established AN behaviors. This pattern of enhanced, followed by impaired dopamine might be a common path to many behavioral disorders characterized by reinforcement learning and subsequent behavioral inflexibility. If correct, our hypothesis has significant clinical and research implications for AN and other disorders, such as addiction and obesity.
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Affiliation(s)
- Jeff A. Beeler
- Department of Psychology, Queens College, City University of New York, Flushing, NY, United States
- Psychology Program, The Graduate Center, CUNY, New York, NY, United States
- Biology Program, The Graduate Center, City University of New York, New York, NY, United States
| | - Nesha S. Burghardt
- Psychology Program, The Graduate Center, CUNY, New York, NY, United States
- Department of Psychology, Hunter College, CUNY, New York, NY, United States
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Beeler JA, Mourra D, Zanca RM, Kalmbach A, Gellman C, Klein BY, Ravenelle R, Serrano P, Moore H, Rayport S, Mingote S, Burghardt NS. Vulnerable and Resilient Phenotypes in a Mouse Model of Anorexia Nervosa. Biol Psychiatry 2021; 90:829-842. [PMID: 32950210 PMCID: PMC7855473 DOI: 10.1016/j.biopsych.2020.06.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND Increased physical activity is a common feature of anorexia nervosa (AN). Although high activity levels are associated with greater risk of developing AN, particularly when combined with dieting, most individuals who diet and exercise maintain a healthy body weight. It is unclear why some individuals develop AN while most do not. A rodent model of resilience and vulnerability to AN would be valuable to research. Dopamine, which is believed to play a crucial role in AN, regulates both reward and activity and may modulate vulnerability. METHODS Adolescent and young adult female C57BL/6N mice were tested in the activity-based anorexia (ABA) model, with an extended period of food restriction in adult mice. ABA was also tested in dopamine transporter knockdown mice and wild-type littermates. Mice that adapted to conditions and maintained a stable body weight were characterized as resilient. RESULTS In adults, vulnerable and resilient phenotypes emerged in both the ABA and food-restricted mice without wheels. Vulnerable mice exhibited a pronounced increase in running throughout the light cycle, which dramatically peaked prior to requiring removal from the experiment. Resilient mice exhibited an adaptive decrease in total running, appropriate food anticipatory activity, and increased consumption, thereby achieving stable body weight. Hyperdopaminergia accelerated progression of the vulnerable phenotype. CONCLUSIONS Our demonstration of distinct resilient and vulnerable phenotypes in mouse ABA significantly advances the utility of the model for identifying genes and neural substrates mediating AN risk and resilience. Modulation of dopamine may play a central role in the underlying circuit.
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Affiliation(s)
- Jeff A. Beeler
- Dept. of Psychology, Queens College and The Graduate Center, CUNY, Flushing, NY, 11367 USA
| | - Devry Mourra
- Dept. of Psychology, Queens College and The Graduate Center, CUNY, Flushing, NY, 11367 USA
| | - Roseanna M. Zanca
- Dept. of Psychology, Hunter College and The Graduate Center, CUNY, New York, NY, 10065 USA
| | - Abigail Kalmbach
- Dept. of Psychiatry, Columbia University, New York, NY, 10032 USA
| | - Celia Gellman
- Dept. of Psychiatry, Columbia University, New York, NY, 10032 USA,Dept. of Molecular Therapeutics, NYS Psychiatric Institute, New York, NY 10032 USA
| | - Benjamin Y. Klein
- Dept. of Psychiatry, Columbia University, New York, NY, 10032 USA,Dept. of Developmental Neuroscience, NYS Psychiatric Institute, New York, NY 10031 USA,Dept. of Microbiology and Molecular Genetics, Hebrew University, Jerusalem, Israel
| | | | - Peter Serrano
- Dept. of Psychology, Hunter College and The Graduate Center, CUNY, New York, NY, 10065 USA
| | - Holly Moore
- Dept. of Psychiatry, Columbia University, New York, NY, 10032 USA,Dept. of Systems Neuroscience, NYS Psychiatric Institute, New York, NY 10032 USA,National Institute on Drug Abuse, Bethesda, MD
| | - Stephen Rayport
- Dept. of Psychiatry, Columbia University, New York, NY, 10032 USA,Dept. of Molecular Therapeutics, NYS Psychiatric Institute, New York, NY 10032 USA
| | - Susana Mingote
- Dept. of Psychiatry, Columbia University, New York, NY, 10032 USA,Dept. of Molecular Therapeutics, NYS Psychiatric Institute, New York, NY 10032 USA,Advanced Science Research Center, The Graduate Center, CUNY, New York, NY 10031 USA
| | - Nesha S. Burghardt
- Dept. of Psychology, Hunter College and The Graduate Center, CUNY, New York, NY, 10065 USA,Dept. of Psychiatry, Columbia University, New York, NY, 10032 USA
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7
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Spadini S, Ferro M, Lamanna J, Malgaroli A. Activity-based anorexia animal model: a review of the main neurobiological findings. J Eat Disord 2021; 9:123. [PMID: 34600568 PMCID: PMC8487535 DOI: 10.1186/s40337-021-00481-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/15/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The genesis of anorexia nervosa (AN), a severe eating disorder with a pervasive effect on many brain functions such as attention, emotions, reward processing, cognition and motor control, has not yet been understood. Since our current knowledge of the genetic aspects of AN is limited, we are left with a large and diversified number of biological, psychological and environmental risk factors, called into question as potential triggers of this chronic condition with a high relapse rate. One of the most valid and used animal models for AN is the activity-based anorexia (ABA), which recapitulates important features of the human condition. This model is generated from naïve rodents by a self-motivated caloric restriction, where a fixed schedule food delivery induces spontaneous increased physical activity. AIM In this review, we sought to provide a summary of the experimental research conducted using the ABA model in the pursuit of potential neurobiological mechanism(s) underlying AN. METHOD The experimental work presented here includes evidence for neuroanatomical and neurophysiological changes in several brain regions as well as for the dysregulation of specific neurochemical synaptic and neurohormonal pathways. RESULTS The most likely hypothesis for the mechanism behind the development of the ABA phenotype relates to an imbalance of the neural circuitry that mediates reward processing. Evidence collected here suggests that ABA animals show a large set of alterations, involving regions whose functions extend way beyond the control of reward mechanisms and eating habits. Hence, we cannot exclude a primary role of these alterations from a mechanistic theory of ABA induction. CONCLUSIONS These findings are not sufficient to solve such a major enigma in neuroscience, still they could be used to design ad hoc further experimental investigation. The prospect is that, since treatment of AN is still challenging, the ABA model could be more effectively used to shed light on the complex AN neurobiological framework, thus supporting the future development of therapeutic strategies but also the identification of biomarkers and diagnostic tools. Anorexia Nervosa (AN) is a severe eating disorder with a dramatic effect on many functions of our brain, such as attention, emotions, cognition and motion control. Since our current knowledge of the genetic aspects behind the development of AN is still limited, many biological, psychological and environmental factors must be taken into account as potential triggers of this condition. One of the most valid animal models for studying AN is the activity-based anorexia (ABA). In this model, rodents spontaneously limit food intake and start performing increased physical activity on a running wheel, a result of the imposition of a fixed time schedule for food delivery. In this review, we provide a detailed summary of the experimental research conducted using the ABA model, which includes extended evidence for changes in the anatomy and function of the brain of ABA rodents. The hope is that such integrated view will support the design of future experiments that will shed light on the complex brain mechanisms behind AN. Such advanced knowledge is crucial to find new, effective strategies for both the early diagnosis of AN and for its treatment.
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Affiliation(s)
- Sara Spadini
- Center for Behavioral Neuroscience and Communication (BNC), Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy
| | - Mattia Ferro
- Center for Behavioral Neuroscience and Communication (BNC), Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy
- Department of Psychology, Sigmund Freud University, Milan, Italy
| | - Jacopo Lamanna
- Center for Behavioral Neuroscience and Communication (BNC), Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy
- Faculty of Psychology, Vita-Salute San Raffaele University, Milan, Italy
| | - Antonio Malgaroli
- Center for Behavioral Neuroscience and Communication (BNC), Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy.
- Faculty of Psychology, Vita-Salute San Raffaele University, Milan, Italy.
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Beeler JA, Burghardt NS. Activity-based Anorexia for Modeling Vulnerability and Resilience in Mice. Bio Protoc 2021; 11:e4009. [PMID: 34124309 DOI: 10.21769/bioprotoc.4009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 02/28/2021] [Accepted: 03/02/2021] [Indexed: 12/25/2022] Open
Abstract
Activity-based anorexia (ABA) is a widely used rodent model of anorexia nervosa. It involves combining limited access to food with unlimited access to a running wheel, leading to a paradoxical decrease in food intake, hyperactivity, and life-threatening weight loss. Although initially characterized in rats, ABA has been tested in mice with results that vary based on strain, sex, age, the amount of time food is available, and the number of days of food restriction. Here, we present our ABA protocol for modeling both vulnerability and resilience to diet and exercise in C57BL/6 female mice. While vulnerable mice exhibit the expected increase in running, reduction in food intake, and excessive weight loss, resilient mice exhibit an adaptive increase in food intake, decrease in total wheel running, and weight stabilization. In contrast to previous ABA studies in which resilience is defined by the relative rate of weight loss, our protocol leads to a resilient phenotype that more closely resembles the maintenance of a stable bodyweight exhibited by most humans who diet and exercise without developing anorexia nervosa. This protocol will be useful for future studies aimed at identifying the physiological and neural adaptations underlying both resilience and vulnerability to this eating disorder.
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Affiliation(s)
- Jeff A Beeler
- Department of Psychology, Queens College, CUNY, Flushing, NY, USA.,Psychology Program, The Graduate Center, CUNY, New York, NY, USA.,Biology Program, The Graduate Center, CUNY, New York, NY, USA
| | - Nesha S Burghardt
- Department of Psychology, Hunter College, CUNY, New York, NY, USA.,Psychology Program, The Graduate Center, CUNY, New York, NY, USA
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9
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Scharner S, Stengel A. Animal Models for Anorexia Nervosa-A Systematic Review. Front Hum Neurosci 2021; 14:596381. [PMID: 33551774 PMCID: PMC7854692 DOI: 10.3389/fnhum.2020.596381] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 12/16/2020] [Indexed: 12/16/2022] Open
Abstract
Anorexia nervosa is an eating disorder characterized by intense fear of gaining weight and a distorted body image which usually leads to low caloric intake and hyperactivity. The underlying mechanism and pathogenesis of anorexia nervosa is still poorly understood. In order to learn more about the underlying pathophysiology of anorexia nervosa and to find further possible treatment options, several animal models mimicking anorexia nervosa have been developed. The aim of this review is to systematically search different databases and provide an overview of existing animal models and to discuss the current knowledge gained from animal models of anorexia nervosa. For the systematic data search, the Pubmed—Medline database, Embase database, and Web of Science database were searched. After removal of duplicates and the systematic process of selection, 108 original research papers were included in this systematic review. One hundred and six studies were performed with rodents and 2 on monkeys. Eighteen different animal models for anorexia nervosa were used in these studies. Parameters assessed in many studies were body weight, food intake, physical activity, cessation of the estrous cycle in female animals, behavioral changes, metabolic and hormonal alterations. The most commonly used animal model (75 of the studies) is the activity-based anorexia model in which typically young rodents are exposed to time-reduced access to food (a certain number of hours a day) with unrestricted access to a running wheel. Of the genetic animal models, one that is of particular interest is the anx/anx mice model. Animal models have so far contributed many findings to the understanding of mechanisms of hunger and satiety, physical activity and cognition in an underweight state and other mechanisms relevant for anorexia nervosa in humans.
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Affiliation(s)
- Sophie Scharner
- Department for Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Berlin Institute of Health, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Andreas Stengel
- Department for Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Berlin Institute of Health, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.,Department of Psychosomatic Medicine and Psychotherapy, University Hospital Tübingen, Tübingen, Germany
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10
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Chowdhury TG, Fenton AA, Aoki C. Effects of adolescent experience of food restriction and exercise on spatial learning and open field exploration of female rats. Hippocampus 2020; 31:170-188. [PMID: 33146453 DOI: 10.1002/hipo.23275] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 08/29/2020] [Accepted: 10/11/2020] [Indexed: 11/08/2022]
Abstract
The hippocampus carries out multiple functions: spatial cognition dorsally (DH) and regulation of emotionality-driven behavior ventrally (VH). Previously, we showed that dendrites of DH and VH pyramidal neurons of female rats are still developing robustly during adolescence and are altered by the experience of food restriction and voluntary exercise on a wheel. We tested whether such anatomical changes during adolescence impact anxiety-like behavior and spatial cognition. Four groups of female rats were evaluated for these behaviors: those with wheel access in its cage from postnatal day (P) 36-44 (EX); those with food access restricted to 1 hr per day, from P40 to 44 (FR); those with EX from P36 to 44, combined with FR from P40 to 44, which we will refer to as EX + FR; and controls, CON (no EX, no FR). Open field test for anxiety-like behavior and active place avoidance test for spatial cognition were conducted at P47-49, the age when food restricted animals have restored body weight, or at P54-56, to identify more enduring effects. Anxiety-like behavior was elevated for the EX and FR groups at P47-49 but not for the EX + FR group. By P54-56, the EX + FR and EX groups exhibited less anxiety-like behavior, indicating a beneficial delayed main effect of exercise. There was a beneficial main effect of food restriction upon cognition, as the FR group showed cognition superior to CONs' at P44-46 and P54-56, while the EX + FR animals also showed enhanced spatial learning at P54-56. EX + FR animals with best adaptation to the feeding schedule showed the best spatial learning performance but with a delay. The EX group exhibited only a transient improvement. These findings indicate that FR, EX, and EX + FR in mid-adolescence are all beneficial in reducing anxiety-like behavior and improving spatial cognition but with subtle differences in the timing of their manifestation, possibly reflecting the protracted maturation of the hippocampus.
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Affiliation(s)
- Tara G Chowdhury
- Center for Neural Science, New York University, New York, New York, USA
| | - André A Fenton
- Center for Neural Science, New York University, New York, New York, USA
| | - Chiye Aoki
- Center for Neural Science, New York University, New York, New York, USA
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11
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Díaz-Rúa A, Chivite M, Comesaña S, Velasco C, Valente LMP, Soengas JL, Conde-Sieira M. The endocannabinoid system is affected by a high-fat-diet in rainbow trout. Horm Behav 2020; 125:104825. [PMID: 32771417 DOI: 10.1016/j.yhbeh.2020.104825] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 01/07/2023]
Abstract
The endocannabinoid system (ECs) is a well known contributor to the hedonic regulation of food intake (FI) in mammals whereas in fish, the knowledge regarding hedonic mechanisms that control FI is limited. Previous studies reported the involvement of ECs in FI regulation in fish since anandamide (AEA) treatment induced enhanced FI and changes of mRNA abundance of appetite-related neuropeptides through cannabinoid receptor 1 (cnr1). However, no previous studies in fish evaluated the impact of palatable food like high-fat diets (HFD) on mechanisms involved in hedonic regulation of FI including the possible involvement of ECs. Therefore, we aimed to evaluate the effect of feeding a HFD on the response of ECs in rainbow trout (Oncorhynchus mykiss). First, we demonstrated a higher intake over 4 days of HFD compared with a control diet (CD). Then, we evaluated the postprandial response (1, 3 and 6 h) of components of the ECs in plasma, hypothalamus, and telencephalon after feeding fish with CD and HFD. The results obtained indicate that the increased FI of HFD occurred along with increased levels of 2-arachidonoylglycerol (2-AG) and AEA in plasma and in brain areas like hypothalamus and telencephalon putatively involved in hedonic regulation of FI in fish. Decreased mRNA abundance of EC receptors like cnr1, gpr55 and trpv1 suggest a feed-back counter-regulatory mechanism in response to the increased levels of EC. Furthermore, the results also suggest that neural activity players associated to FI regulation in mammals as cFOS, γ-Amino butyric acid (GABA) and brain derived neurotrophic factor (BDNF)/neurotrophic receptor tyrosine kinase (NTRK) systems could be involved in the hedonic eating response to a palatable diet in fish.
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Affiliation(s)
- Adrián Díaz-Rúa
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidade de Vigo, Spain
| | - Mauro Chivite
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidade de Vigo, Spain
| | - Sara Comesaña
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidade de Vigo, Spain
| | - Cristina Velasco
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidade de Vigo, Spain
| | - Luisa M P Valente
- CIIMAR/CIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros do Porto de Leixões. Av. General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal; ICBAS, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - José L Soengas
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidade de Vigo, Spain
| | - Marta Conde-Sieira
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidade de Vigo, Spain.
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12
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Gorrell S, Collins AG, Le Grange D, Yang TT. Dopaminergic activity and exercise behavior in anorexia nervosa. OBM NEUROBIOLOGY 2020; 4:10.21926/obm.neurobiol.2001053. [PMID: 33569542 PMCID: PMC7872149 DOI: 10.21926/obm.neurobiol.2001053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Driven exercise (i.e., the tendency to exercise in excess to influence weight/shape or regulate emotion) is difficult to manage in the context of anorexia nervosa, and is associated with poorer treatment outcomes, and psychological and medical severity. Driven exercise is observed in a considerable number of those diagnosed with anorexia nervosa; however, to date, this hallmark symptom remains poorly understood. Dopamine signaling is implicated in motivating and maintaining appetitive behavior among patients with eating disorders; but, much less is known about the role of dopamine signaling specific to the symptom of driven exercise. An improved understanding of this biobehavioral mechanism may inform the etiology of driven exercise in anorexia nervosa, with the potential to impact future research and treatment efforts. This review describes the role that dopamine serves in maintaining symptoms in the context of anorexia nervosa, and synthesizes current relevant evidence on exercise in AN and related dopaminergic activity. Throughout, theoretical implications are discussed, along with critical directions for future research.
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Affiliation(s)
- Sasha Gorrell
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Anne G.E. Collins
- Department of Psychology and Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - Daniel Le Grange
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Psychiatry & Behavioral Neuroscience, The University of Chicago, Chicago, IL, USA (Emeritus)
| | - Tony T. Yang
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
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13
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Schalla MA, Stengel A. Activity Based Anorexia as an Animal Model for Anorexia Nervosa-A Systematic Review. Front Nutr 2019; 6:69. [PMID: 31165073 PMCID: PMC6536653 DOI: 10.3389/fnut.2019.00069] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/25/2019] [Indexed: 12/14/2022] Open
Abstract
Anorexia nervosa (AN) is a severe eating disorder affecting around 1 per 100 persons. However, the knowledge about its underlying pathophysiology is limited. To address the need for a better understanding of AN, an animal model was established early on in the late 1960's: the activity-based anorexia (ABA) model in which rats have access to a running wheel combined with restricted food access leading to self-starving/body weight loss and hyperactivity. Both symptoms, separately or combined, can also be found in patients with AN. The aim of this systematic review was to compile the current knowledge about this animal model as well as to address gaps in knowledge. Using the data bases of PubMed, Embase and Web of science 102 publications were identified meeting the search criteria. Here, we show that the ABA model mimics core features of human AN and has been characterized with regards to brain alterations, hormonal changes as well as adaptations of the immune system. Moreover, pharmacological interventions in ABA animals and new developments, such as a chronic adaptation of the ABA model, will be highlighted. The chronic model might be well suited to display AN characteristics but should be further characterized. Lastly, limitations of the model will be discussed.
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Affiliation(s)
- Martha A Schalla
- Department for Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Berlin Institute of Health, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Andreas Stengel
- Department for Psychosomatic Medicine, Charité Center for Internal Medicine and Dermatology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Berlin Institute of Health, Humboldt-Universität zu Berlin, Berlin, Germany.,Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital Tübingen, Tübingen, Germany
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14
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AOKI C, CHEN YW, CHOWDHURY TG, PIPER W. α4βδ-GABA A receptors in dorsal hippocampal CA1 of adolescent female rats traffic to the plasma membrane of dendritic spines following voluntary exercise and contribute to protection of animals from activity-based anorexia through localization at excitatory synapses. J Neurosci Res 2018; 96:1450-1466. [PMID: 28218471 PMCID: PMC5563482 DOI: 10.1002/jnr.24035] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 01/17/2017] [Accepted: 01/18/2017] [Indexed: 01/22/2023]
Abstract
In hippocampal CA1 of adolescent female rodents, α4βδ-GABAA receptors (α4βδ-GABAA Rs) suppress excitability of pyramidal neurons through shunting inhibition at excitatory synapses. This contributes to anxiolysis of stressed animals. Socially isolated adolescent female rats with 8 days of wheel access, the last 4 days of which entail restricted food access, have been shown to exhibit excessive exercise, choosing to run instead of eat (activity-based anorexia [ABA]). Upregulation of α4βδ-GABAA Rs in the dorsal hippocampal CA1 (DH), seen among some ABA animals, correlates with suppression of excessive exercise. We used electron microscopic immunocytochemistry to show that exercise alone (EX), but not food restriction alone (FR), also augments α4βδ-GABAA R expression at axospinous excitatory synapses of the DH (67%, P = 0.027), relative to socially isolated controls without exercise or food restriction (CON). Relative to CON, ABA animals' synaptic α4βδ-GABAA R elevation was modestly elevated (37%), but this level correlated strongly and negatively with individual differences in ABA vulnerability-i.e., food restriction-evoked hyperactivity (Pearson R = -0.902, P = 0.002) and weight changes (R = 0.822, P = 0.012). These correlations were absent from FR and EX brains or ventral hippocampus of ABA brains. Comparison to CON of α4βδ-GABAA R location in the DH indicated that ABA induces trafficking of α4βδ-GABAA R from reserve pools in spine cytoplasm to excitatory synapses. Pair-housing CON animals reduced cytoplasmic α4βδ-GABAA R without reducing synaptic α4βδ-GABAA R. Thus, exercise induces trafficking of α4βδ-GABAA Rs to excitatory synapses, while individual differences in ABA vulnerability are linked most strongly to trafficking of α4βδ-GABAA Rs in the reverse direction-from excitatory synapses to the reserve pool during co-occurring food restriction. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Chiye AOKI
- Center for Neural Sci., New York University, New York, NY, 10003
| | - Yi-Wen CHEN
- Center for Neural Sci., New York University, New York, NY, 10003
| | | | - Walter PIPER
- Center for Neural Sci., New York University, New York, NY, 10003
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15
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Hinney A, Kesselmeier M, Jall S, Volckmar AL, Föcker M, Antel J, Heid IM, Winkler TW, Grant SFA, Guo Y, Bergen AW, Kaye W, Berrettini W, Hakonarson H, Herpertz-Dahlmann B, de Zwaan M, Herzog W, Ehrlich S, Zipfel S, Egberts KM, Adan R, Brandys M, van Elburg A, Boraska Perica V, Franklin CS, Tschöp MH, Zeggini E, Bulik CM, Collier D, Scherag A, Müller TD, Hebebrand J. Evidence for three genetic loci involved in both anorexia nervosa risk and variation of body mass index. Mol Psychiatry 2017; 22:192-201. [PMID: 27184124 PMCID: PMC5114162 DOI: 10.1038/mp.2016.71] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 02/22/2016] [Accepted: 03/17/2016] [Indexed: 02/06/2023]
Abstract
The maintenance of normal body weight is disrupted in patients with anorexia nervosa (AN) for prolonged periods of time. Prior to the onset of AN, premorbid body mass index (BMI) spans the entire range from underweight to obese. After recovery, patients have reduced rates of overweight and obesity. As such, loci involved in body weight regulation may also be relevant for AN and vice versa. Our primary analysis comprised a cross-trait analysis of the 1000 single-nucleotide polymorphisms (SNPs) with the lowest P-values in a genome-wide association meta-analysis (GWAMA) of AN (GCAN) for evidence of association in the largest published GWAMA for BMI (GIANT). Subsequently we performed sex-stratified analyses for these 1000 SNPs. Functional ex vivo studies on four genes ensued. Lastly, a look-up of GWAMA-derived BMI-related loci was performed in the AN GWAMA. We detected significant associations (P-values <5 × 10-5, Bonferroni-corrected P<0.05) for nine SNP alleles at three independent loci. Interestingly, all AN susceptibility alleles were consistently associated with increased BMI. None of the genes (chr. 10: CTBP2, chr. 19: CCNE1, chr. 2: CARF and NBEAL1; the latter is a region with high linkage disequilibrium) nearest to these SNPs has previously been associated with AN or obesity. Sex-stratified analyses revealed that the strongest BMI signal originated predominantly from females (chr. 10 rs1561589; Poverall: 2.47 × 10-06/Pfemales: 3.45 × 10-07/Pmales: 0.043). Functional ex vivo studies in mice revealed reduced hypothalamic expression of Ctbp2 and Nbeal1 after fasting. Hypothalamic expression of Ctbp2 was increased in diet-induced obese (DIO) mice as compared with age-matched lean controls. We observed no evidence for associations for the look-up of BMI-related loci in the AN GWAMA. A cross-trait analysis of AN and BMI loci revealed variants at three chromosomal loci with potential joint impact. The chromosome 10 locus is particularly promising given that the association with obesity was primarily driven by females. In addition, the detected altered hypothalamic expression patterns of Ctbp2 and Nbeal1 as a result of fasting and DIO implicate these genes in weight regulation.
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Affiliation(s)
- A Hinney
- Department of Child and Adolescent Psychiatry, Psychotherapy, and Psychosomatics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - M Kesselmeier
- Clinical Epidemiology, Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - S Jall
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center & German Diabetes Center (DZD), Helmholtz Zentrum München, Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - A-L Volckmar
- Department of Child and Adolescent Psychiatry, Psychotherapy, and Psychosomatics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - M Föcker
- Department of Child and Adolescent Psychiatry, Psychotherapy, and Psychosomatics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - J Antel
- Department of Child and Adolescent Psychiatry, Psychotherapy, and Psychosomatics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - I M Heid
- Department of Genetic Epidemiology, University of Regensburg, Regensburg, Germany
| | - T W Winkler
- Department of Genetic Epidemiology, University of Regensburg, Regensburg, Germany
| | - S F A Grant
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA, USA
- Divisions of Genetics and Endocrinology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- The Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Y Guo
- The Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | | | - W Kaye
- Department of Psychiatry, University of California, San Diego, San Diego, CA, USA
| | - W Berrettini
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA
| | - H Hakonarson
- The Division of Human Genetics, Department of Pediatrics, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - B Herpertz-Dahlmann
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of the RWTH Aachen, Aachen, Germany
| | - M de Zwaan
- Department of Psychosomatic Medicine and Psychotherapy, Hannover Medical School, Hannover, Germany
| | - W Herzog
- Department of Internal Medicine II, General Internal and Psychosomatic Medicine, University of Heidelberg, Heidelberg, Germany
| | - S Ehrlich
- Translational Developmental Neuroscience Section, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU-Dresden, University Hospital Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - S Zipfel
- Department of Psychosomatic Medicine and Psychotherapy, Medical University Hospital, Tübingen, Germany
| | - K M Egberts
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany
| | - R Adan
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
- Altrecht Eating Disorders Rintveld, Zeist, The Netherlands
| | - M Brandys
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
- Altrecht Eating Disorders Rintveld, Zeist, The Netherlands
| | - A van Elburg
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - V Boraska Perica
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
- University of Split School of Medicine, Split, Croatia
| | - C S Franklin
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - M H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center & German Diabetes Center (DZD), Helmholtz Zentrum München, Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - E Zeggini
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - C M Bulik
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Nutrition, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - D Collier
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
- Eli Lilly and Company Ltd, Surrey, UK
| | - A Scherag
- Clinical Epidemiology, Integrated Research and Treatment Center, Center for Sepsis Control and Care (CSCC), Jena University Hospital, Jena, Germany
| | - T D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center & German Diabetes Center (DZD), Helmholtz Zentrum München, Neuherberg, Germany
- Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - J Hebebrand
- Department of Child and Adolescent Psychiatry, Psychotherapy, and Psychosomatics, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
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16
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Ho EV, Klenotich SJ, McMurray MS, Dulawa SC. Activity-Based Anorexia Alters the Expression of BDNF Transcripts in the Mesocorticolimbic Reward Circuit. PLoS One 2016; 11:e0166756. [PMID: 27861553 PMCID: PMC5115804 DOI: 10.1371/journal.pone.0166756] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/03/2016] [Indexed: 12/16/2022] Open
Abstract
Anorexia nervosa (AN) is a complex eating disorder with severe dysregulation of appetitive behavior. The activity-based anorexia (ABA) paradigm is an animal model in which rodents exposed to both running wheels and scheduled feeding develop aspects of AN including paradoxical hypophagia, dramatic weight loss, and hyperactivity, while animals exposed to only one condition maintain normal body weight. Brain-derived neurotrophic factor (BDNF), an activity-dependent modulator of neuronal plasticity, is reduced in the serum of AN patients, and is a known regulator of feeding and weight maintenance. We assessed the effects of scheduled feeding, running wheel access, or both on the expression of BDNF transcripts within the mesocorticolimbic pathway. We also assessed the expression of neuronal cell adhesion molecule 1 (NCAM1) to explore the specificity of effects on BDNF within the mesocorticolimbic pathway. Scheduled feeding increased the levels of both transcripts in the hippocampus (HPC), increased NCAM1 mRNA expression in the ventral tegmental area (VTA), and decreased BDNF mRNA levels in the medial prefrontal cortex (mPFC). In addition, wheel running increased BDNF mRNA expression in the VTA. No changes in either transcript were observed in the nucleus accumbens (NAc). Furthermore, no changes in either transcript were induced by the combined scheduled feeding and wheel access condition. These data indicate that scheduled feeding or wheel running alter BDNF and NCAM1 expression levels in specific regions of the mesocorticolimbic pathway. These findings contribute to our current knowledge of the molecular alterations induced by ABA and may help elucidate possible mechanisms of AN pathology.
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Affiliation(s)
- Emily V. Ho
- Department of Psychiatry, University of California San Diego, La Jolla, California, United States of America
| | - Stephanie J. Klenotich
- Department of Psychiatry, University of Chicago, Chicago, Illinois, United States of America
| | - Matthew S. McMurray
- Department of Psychology, University of Illinois Chicago, Chicago, Illinois, United States of America
| | - Stephanie C Dulawa
- Department of Psychiatry, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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17
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O’Hara CB, Keyes A, Renwick B, Giel KE, Campbell IC, Schmidt U. Evidence that Illness-Compatible Cues Are Rewarding in Women Recovered from Anorexia Nervosa: A Study of the Effects of Dopamine Depletion on Eye-Blink Startle Responses. PLoS One 2016; 11:e0165104. [PMID: 27764214 PMCID: PMC5072564 DOI: 10.1371/journal.pone.0165104] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 09/28/2016] [Indexed: 01/01/2023] Open
Abstract
In anorexia nervosa (AN), motivational salience is attributed to illness-compatible cues (e.g., underweight and active female bodies) and this is hypothesised to involve dopaminergic reward circuitry. We investigated the effects of reducing dopamine (DA) transmission on the motivational processing of AN-compatible cues in women recovered from AN (AN REC, n = 17) and healthy controls (HC, n = 15). This involved the acute phenylalanine and tyrosine depletion (APTD) procedure and a startle eye-blink modulation (SEM) task. In a balanced amino acid state, AN REC showed an increased appetitive response (decreased startle potentiation) to illness-compatible cues (underweight and active female body pictures (relative to neutral and non-active cues, respectively)). The HC had an aversive response (increased startle potentiation) to the same illness-compatible stimuli (relative to neutral cues). Importantly, these effects, which may be taken to resemble symptoms observed in the acute stage of illness and healthy behaviour respectively, were not present when DA was depleted. Thus, AN REC implicitly appraised underweight and exercise cues as more rewarding than did HC and the process may, in part, be DA-dependent. It is proposed that the positive motivational salience attributed to cues of emaciation and physical activity is, in part, mediated by dopaminergic reward processes and this contributes to illness pathology. These observations are consistent with the proposal that, in AN, aberrant reward-based learning contributes to the development of habituation of AN-compatible behaviours.
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Affiliation(s)
- Caitlin B. O’Hara
- King’s College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Psychological Medicine, Section of Eating Disorders, London, United Kingdom
- * E-mail: caitlin.b.o’
| | - Alexandra Keyes
- King’s College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Psychological Medicine, Section of Eating Disorders, London, United Kingdom
| | - Bethany Renwick
- King’s College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Psychological Medicine, Section of Eating Disorders, London, United Kingdom
| | - Katrin E. Giel
- Medical University Hospital Tübingen, Department of Psychosomatic Medicine and Psychotherapy, Tübingen, Germany
| | - Iain C. Campbell
- King’s College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Psychological Medicine, Section of Eating Disorders, London, United Kingdom
| | - Ulrike Schmidt
- King’s College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Psychological Medicine, Section of Eating Disorders, London, United Kingdom
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18
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O’Hara CB, Keyes A, Renwick B, Leyton M, Campbell IC, Schmidt U. The Effects of Acute Dopamine Precursor Depletion on the Reinforcing Value of Exercise in Anorexia Nervosa. PLoS One 2016; 11:e0145894. [PMID: 26808920 PMCID: PMC4726788 DOI: 10.1371/journal.pone.0145894] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/09/2015] [Indexed: 11/18/2022] Open
Abstract
This study investigated whether dopaminergic systems are involved in the motivation to engage in behaviours associated with anorexia nervosa (AN), specifically, the drive to exercise. Women recovered from AN (AN REC, n = 17) and healthy controls (HC, n = 15) were recruited. The acute phenylalanine/tyrosine depletion (APTD) method was used to transiently decrease dopamine synthesis and transmission. The effect of dopamine precursor depletion on drive to exercise was measured using a progressive ratio (PR) exercise breakpoint task. Both groups worked for the opportunity to exercise, and, at baseline, PR breakpoint scores were higher in AN REC than HC. Compared to values on the experimental control session, APTD did not decrease PR breakpoint scores in AN REC, but significantly decreased scores in HC. These data show that women recovered from AN are more motivated to exercise than HC, although in both groups, activity is more reinforcing than inactivity. Importantly, decreasing dopamine does not reduce the motivation to exercise in people recovered from AN, but in contrast, does so in HC. It is proposed that in AN, drive to exercise develops into a behaviour that is largely independent of dopamine mediated reward processes and becomes dependent on cortico-striatal neurocircuitry that regulates automated, habit- or compulsive-like behaviours. These data strengthen the case for the involvement of reward, learning, habit, and dopaminergic systems in the aetiology of AN.
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Affiliation(s)
- Caitlin B. O’Hara
- King’s College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Psychological Medicine, Section of Eating Disorders, London, United Kingdom
- * E-mail: caitlin.b.o’
| | - Alexandra Keyes
- King’s College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Psychological Medicine, Section of Eating Disorders, London, United Kingdom
| | - Bethany Renwick
- King’s College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Psychological Medicine, Section of Eating Disorders, London, United Kingdom
| | - Marco Leyton
- Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Iain C. Campbell
- King’s College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Psychological Medicine, Section of Eating Disorders, London, United Kingdom
| | - Ulrike Schmidt
- King’s College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Psychological Medicine, Section of Eating Disorders, London, United Kingdom
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19
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Peng S, Yu S, Wang Q, Kang Q, Zhang Y, Zhang R, Jiang W, Qian Y, Zhang H, Zhang M, Xiao Z, Chen J. Dopamine receptor D2 and catechol-O-methyltransferase gene polymorphisms associated with anorexia nervosa in Chinese Han population: DRD2 and COMT gene polymorphisms were associated with AN. Neurosci Lett 2016; 616:147-51. [PMID: 26808641 DOI: 10.1016/j.neulet.2016.01.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Revised: 12/28/2015] [Accepted: 01/20/2016] [Indexed: 12/19/2022]
Abstract
Dopamine receptor D2 (DRD2) and catechol-O-methyltransferase (COMT) are important in dopamine system which is proved to be associated with food-anticipatory behavior, food restriction, reward and motivation. This has made them good candidates for anorexia nervosa (AN). The aim of this work is to explore the roles of DRD2 (rs1800497) and COMT (rs4680, rs4633, rs4818) gene polymorphisms in the susceptibility of AN within the Chinese Han population. We recruited 260AN patients with DSM-IV diagnosis criteria, and 247 unrelated, normal weight controls. DRD2 (rs1800497) and COMT (rs4680, rs4633, rs4818) were genotyped in all subjects. We found rs1800497 and rs4633 were associated with the susceptibility of AN within the Chinese Han sample, and allele C of rs1800497 was a protective factor. There was a gene-gene interaction between rs1800497 of DRD2 gene and rs4633 of COMT gene. We concluded that rs1800497 and rs4633 play important roles in the AN susceptibility with respect to the Chinese Han population. The gene-gene interaction between DRD2 and COMT contributes to the risk of AN.
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Affiliation(s)
- Sufang Peng
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Shunying Yu
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China.
| | - Qian Wang
- Med-X Research Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, PR China
| | - Qing Kang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Yanxia Zhang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Ran Zhang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Wenhui Jiang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Yiping Qian
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Haiyin Zhang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Mingdao Zhang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Zeping Xiao
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Jue Chen
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China.
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20
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Vaanholt LM, Mitchell SE, Sinclair RE, Speakman JR. Mice that are resistant to diet-induced weight loss have greater food anticipatory activity and altered melanocortin-3 receptor (MC3R) and dopamine receptor 2 (D2) gene expression. Horm Behav 2015; 73:83-93. [PMID: 26122292 DOI: 10.1016/j.yhbeh.2015.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 06/12/2015] [Accepted: 06/13/2015] [Indexed: 11/20/2022]
Abstract
Diet-induced weight loss varies considerably between individuals, but the mechanisms driving these individual differences remain largely unknown. Here we investigated whether key neuropeptides involved in the regulation of energy balance or reward systems were differentially expressed in mice that were prone or resistant to caloric restriction (CR) induced weight loss. Mice (n=30 males and n=34 females) were fed 70% of their own baseline ad libitum intake for 25days, after which their brains were collected and expression of various neuropeptides were investigated and compared between the 10 male and 10 female mice that showed the greatest (high weight loss, HWL) or lowest weight loss (LWL) (n=40 in total). HWL mice showed a differential neuropeptide profile to LWL in both sexes, characterised by increased expression of neuropeptide Y (NPY), agouti-related peptide (AgRP), leptin receptor (ObRb), and melanocortin 3 receptor (MC3R) in the arcuate nucleus. No changes in the expression of fat mass and obesity related gene (FTO) or suppressor of cytokine signalling 3 (Socs3) were observed. Levels of dopamine D2 receptor were decreased in the nucleus accumbens in HWL compared to LWL mice. HWL mice showed a stronger increase in food anticipatory activity (FAA) in response to CR than LWL mice. These results indicate that the mice prone to diet-induced weight loss experienced greater hunger, potentially driving their elevated FAA.
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MESH Headings
- Animals
- Anticipation, Psychological/physiology
- Arcuate Nucleus of Hypothalamus/metabolism
- Caloric Restriction
- Diet, Reducing
- Energy Metabolism/genetics
- Female
- Food
- Gene Expression
- Humans
- Male
- Mice
- Mice, Obese
- Neuropeptide Y/genetics
- Neuropeptide Y/metabolism
- Obesity/diet therapy
- Obesity/genetics
- Obesity/metabolism
- Receptor, Melanocortin, Type 3/genetics
- Receptor, Melanocortin, Type 3/metabolism
- Receptors, Dopamine D2/genetics
- Receptors, Dopamine D2/metabolism
- Receptors, Leptin/genetics
- Receptors, Leptin/metabolism
- Treatment Failure
- Weight Loss/genetics
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Affiliation(s)
- Lobke M Vaanholt
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK.
| | - Sharon E Mitchell
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - Rachel E Sinclair
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK; State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
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21
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Chen YW, Wable GS, Chowdhury TG, Aoki C. Enlargement of Axo-Somatic Contacts Formed by GAD-Immunoreactive Axon Terminals onto Layer V Pyramidal Neurons in the Medial Prefrontal Cortex of Adolescent Female Mice Is Associated with Suppression of Food Restriction-Evoked Hyperactivity and Resilience to Activity-Based Anorexia. Cereb Cortex 2015; 26:2574-89. [PMID: 25979087 DOI: 10.1093/cercor/bhv087] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Many, but not all, adolescent female mice that are exposed to a running wheel while food restricted (FR) become excessive wheel runners, choosing to run even during the hours of food availability, to the point of death. This phenomenon is called activity-based anorexia (ABA). We used electron microscopic immunocytochemistry to ask whether individual differences in ABA resilience may correlate with the lengths of axo-somatic contacts made by GABAergic axon terminals onto layer 5 pyramidal neurons (L5P) in the prefrontal cortex. Contact lengths were, on average, 40% greater for the ABA-induced mice, relative to controls. Correspondingly, the proportion of L5P perikaryal plasma membrane contacted by GABAergic terminals was 45% greater for the ABA mice. Contact lengths in the anterior cingulate cortex correlated negatively and strongly with the overall wheel activity after FR (R = -0.87, P < 0.01), whereas those in the prelimbic cortex correlated negatively with wheel running specifically during the hours of food availability of the FR days (R = -0.84, P < 0.05). These negative correlations support the idea that increases in the glutamic acid decarboxylase (GAD) terminal contact lengths onto L5P contribute toward ABA resilience through suppression of wheel running, a behavior that is intrinsically rewarding and helpful for foraging but maladaptive within a cage.
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Affiliation(s)
- Yi-Wen Chen
- Center for Neural Science, New York University, New York, NY 10003, USA
| | | | | | - Chiye Aoki
- Center for Neural Science, New York University, New York, NY 10003, USA
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22
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O’Hara CB, Campbell IC, Schmidt U. A reward-centred model of anorexia nervosa: A focussed narrative review of the neurological and psychophysiological literature. Neurosci Biobehav Rev 2015; 52:131-52. [DOI: 10.1016/j.neubiorev.2015.02.012] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 02/09/2015] [Accepted: 02/22/2015] [Indexed: 12/13/2022]
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23
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Wable GS, Min JY, Chen YW, Aoki C. Anxiety is correlated with running in adolescent female mice undergoing activity-based anorexia. Behav Neurosci 2015; 129:170-82. [PMID: 25730124 DOI: 10.1037/bne0000040] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Activity-based anorexia (ABA) is a widely used animal model for identifying the biological basis of excessive exercise and starvation, 2 hallmarks of anorexia nervosa (AN). Anxiety is correlated with exercise in AN. Yet the anxiety level of animals in ABA has not been reported. We asked: Does food restriction as part of ABA induction change the anxiety level of animals? If so, is the degree of anxiety correlated with degree of hyperactivity? We used the open field test before food restriction and the elevated plus maze test (EPM) during food restriction to quantify anxiety among singly housed adolescent female mice and determined whether food restriction alone or combined with exercise (i.e., ABA induction) abates or increases anxiety. We show that food restriction, with or without exercise, reduced anxiety significantly, as measured by the proportion of entries into the open arms of EPM (35.73%, p = .04). Moreover, ABA-induced individuals varied in their open arm time measure of anxiety and this value was highly and negatively correlated to the individual's food restriction-evoked wheel activity during the 24 hr following the anxiety test (R = -.75, p = .004, N = 12). This correlation was absent among the exercise-only controls. In addition, mice with higher increase in anxiety ran more following food restriction. Our data suggest that food restriction-evoked wheel running hyperactivity can be used as a reliable and continuous measure of anxiety in ABA. The parallel relationship between anxiety level and activity in AN and ABA-induced female mice strengthens the animal model.
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Affiliation(s)
| | | | - Yi-Wen Chen
- Center for Neural Science, New York University
| | - Chiye Aoki
- Center for Neural Science, New York University
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24
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Chowdhury TG, Barbarich-Marsteller NC, Chan TE, Aoki C. Activity-based anorexia has differential effects on apical dendritic branching in dorsal and ventral hippocampal CA1. Brain Struct Funct 2014; 219:1935-45. [PMID: 23959245 PMCID: PMC3930623 DOI: 10.1007/s00429-013-0612-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 07/15/2013] [Indexed: 12/21/2022]
Abstract
Anorexia nervosa (AN) is an eating disorder to which adolescent females are particularly vulnerable. Like AN, activity-based anorexia (ABA), a rodent model of AN, results in elevation of stress hormones and has genetic links to anxiety disorders. The hippocampus plays a key role in the regulation of anxiety and responds with structural changes to hormones and stress, suggesting that it may play a role in AN. The hippocampus of ABA animals exhibits increased brain-derived neurotrophic factor and increased GABA receptor expression, but the structural effects of ABA have not been studied. We used Golgi staining of neurons to determine whether ABA in female rats during adolescence results in structural changes to the apical dendrites in hippocampal CA1 and contrasted to the effects of food restriction (FR) and exercise (EX), the environmental factors used to induce ABA. In the dorsal hippocampus, which preferentially mediates spatial learning and cognition, cells of ABA animals had less total dendritic length and fewer dendritic branches in stratum radiatum (SR) than in control (CON). In the ventral hippocampus, which preferentially mediates anxiety, ABA evoked more branching in SR than CON. In both dorsal and ventral regions, the main effect of exercise was localized to the SR while the main effect of food restriction occurred in the stratum lacunosum-moleculare. Taken together with data on spine density, these results indicate that ABA elicits pathway-specific changes in the hippocampus that may underlie the increased anxiety and reduced behavioral flexibility observed in ABA.
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Affiliation(s)
| | - Nicole C. Barbarich-Marsteller
- Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York, NY 10032
- New York State Psychiatric Institute, New York, NY 10032
| | - Thomas E. Chan
- Center for Neural Science, New York University, New York, NY 10003
| | - Chiye Aoki
- Center for Neural Science, New York University, New York, NY 10003
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25
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Smiljanic K, Pesic V, Mladenovic Djordjevic A, Pavkovic Z, Brkic M, Ruzdijic S, Kanazir S. Long-term dietary restriction differentially affects the expression of BDNF and its receptors in the cortex and hippocampus of middle-aged and aged male rats. Biogerontology 2014; 16:71-83. [PMID: 25344640 DOI: 10.1007/s10522-014-9537-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 10/20/2014] [Indexed: 12/17/2022]
Abstract
Dietary restriction (DR) exerts significant beneficial effects in terms of aging and age-related diseases in many organisms including humans. The present study aimed to examine the influence of long-term DR on the BDNF system at the transcriptional and translational levels in the cortex and hippocampus of middle-aged (12-month-old) and aged (24-month-old) male Wistar rats. The obtained results revealed that the DR upregulated the expression of exon-specific BDNF transcripts in both regions, followed by elevated levels of mBDNF only in the cortex in middle-aged animals. In aged animals, DR modulated BDNF protein levels by increasing proBDNF and by declining mBDNF levels. Additionally, elevated levels of the full-length TrkB accompanied by a decreased level of the less-glycosylated TrkB protein were observed in middle-aged rats following DR, while in aged rats, DR amplified only the expression of the less-glycosylated form of TrkB. The levels of phosphorylated TrkB(Y816) were stable during aging regardless of feeding. Reduced levels of p75(NTR) were detected in both regions of middle-aged DR-fed animals, while a significant increase was measured in the cortex of aged DR-fed rats. These findings shed additional light on DR as a modulator of BDNF system revealing its disparate effects in middle-aged and aged animals. Given the importance of the proBDNF/BDNF circuit-level expression in different brain functions and various aspects of behavior, it is necessary to further elucidate the optimal duration of the applied dietary regimen with regard to the animal age in order to achieve its most favorable effects.
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Affiliation(s)
- Kosara Smiljanic
- Laboratory of Molecular Neurobiology, Department of Neurobiology, Institute for Biological Research ''Sinisa Stankovic'', University of Belgrade, Bul D.Stefana 142, 11060, Belgrade, Serbia
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26
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Zwipp J, Hass J, Schober I, Geisler D, Ritschel F, Seidel M, Weiss J, Roessner V, Hellweg R, Ehrlich S. Serum brain-derived neurotrophic factor and cognitive functioning in underweight, weight-recovered and partially weight-recovered females with anorexia nervosa. Prog Neuropsychopharmacol Biol Psychiatry 2014; 54:163-9. [PMID: 24859292 DOI: 10.1016/j.pnpbp.2014.05.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/06/2014] [Accepted: 05/12/2014] [Indexed: 12/11/2022]
Abstract
Several studies support the assumption that the brain-derived neurotrophic factor (BDNF) plays an important role in the pathophysiology of eating disorders. In the present cross-sectional and longitudinal study, we investigated BDNF levels in patients with anorexia nervosa (AN) at different stages of their illness and the association with cognitive functioning. We measured serum BDNF in 72 acutely underweight female AN patients (acAN), 23 female AN patients who successfully recovered from their illness (recAN), and 52 healthy control women (HCW). Longitudinally, 30 acAN patients were reassessed after short-term weight gain. The association between BDNF levels and psychomotor speed was investigated using the Trail Making Test. BDNF serum concentrations were significantly higher in recAN participants if compared to acAN patients and increased with short-term weight gain. In acAN patients, but not HCW, BDNF levels were inversely associated with psychomotor speed. AcAN patients with higher BDNF levels also had lower life time body mass indexes. Taken together, our results indicate that serum BDNF levels in patients with AN vary with the stage of illness. Based on the pleiotropic functions of BDNF, changing levels of this neurotrophin may have different context-dependent effects, one of which may be the modulation of cognitive functioning in acutely underweight patients.
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Affiliation(s)
- Johannes Zwipp
- Department of Child and Adolescent Psychiatry and Psychotherapy, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Johanna Hass
- Department of Child and Adolescent Psychiatry and Psychotherapy, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Ilka Schober
- Department of Child and Adolescent Psychiatry and Psychotherapy, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Daniel Geisler
- Department of Child and Adolescent Psychiatry and Psychotherapy, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Franziska Ritschel
- Department of Child and Adolescent Psychiatry and Psychotherapy, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Maria Seidel
- Department of Child and Adolescent Psychiatry and Psychotherapy, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Jessika Weiss
- Department of Child and Adolescent Psychiatry and Psychotherapy, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Veit Roessner
- Department of Child and Adolescent Psychiatry and Psychotherapy, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
| | - Rainer Hellweg
- Department of Psychiatry and Psychotherapy, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Stefan Ehrlich
- Department of Child and Adolescent Psychiatry and Psychotherapy, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany; MGH/MIT/HMS Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA; Harvard Medical School, Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA.
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27
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van Gestel MA, Kostrzewa E, Adan RAH, Janhunen SK. Pharmacological manipulations in animal models of anorexia and binge eating in relation to humans. Br J Pharmacol 2014; 171:4767-84. [PMID: 24866852 PMCID: PMC4209941 DOI: 10.1111/bph.12789] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 03/07/2014] [Accepted: 05/16/2014] [Indexed: 12/22/2022] Open
Abstract
Eating disorders, such as anorexia nervosa (AN), bulimia nervosa (BN) and binge eating disorders (BED), are described as abnormal eating habits that usually involve insufficient or excessive food intake. Animal models have been developed that provide insight into certain aspects of eating disorders. Several drugs have been found efficacious in these animal models and some of them have eventually proven useful in the treatment of eating disorders. This review will cover the role of monoaminergic neurotransmitters in eating disorders and their pharmacological manipulations in animal models and humans. Dopamine, 5-HT (serotonin) and noradrenaline in hypothalamic and striatal regions regulate food intake by affecting hunger and satiety and by affecting rewarding and motivational aspects of feeding. Reduced neurotransmission by dopamine, 5-HT and noradrenaline and compensatory changes, at least in dopamine D2 and 5-HT(2C/2A) receptors, have been related to the pathophysiology of AN in humans and animal models. Also, in disorders and animal models of BN and BED, monoaminergic neurotransmission is down-regulated but receptor level changes are different from those seen in AN. A hypofunctional dopamine system or overactive α2-adrenoceptors may contribute to an attenuated response to (palatable) food and result in hedonic binge eating. Evidence for the efficacy of monoaminergic treatments for AN is limited, while more support exists for the treatment of BN or BED with monoaminergic drugs.
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Affiliation(s)
- M A van Gestel
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center UtrechtUtrecht, The Netherlands
| | - E Kostrzewa
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center UtrechtUtrecht, The Netherlands
| | - R A H Adan
- Brain Center Rudolf Magnus, Department of Translational Neuroscience, University Medical Center UtrechtUtrecht, The Netherlands
| | - S K Janhunen
- Orion Corporation Orion Pharma, Research and Development, CNS ResearchTurku, Finland
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28
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Yilmaz Z, Kaplan AS, Tiwari AK, Levitan RD, Piran S, Bergen AW, Kaye WH, Hakonarson H, Wang K, Berrettini WH, Brandt HA, Bulik CM, Crawford S, Crow S, Fichter MM, Halmi KA, Johnson CL, Keel PK, Klump KL, Magistretti P, Mitchell JE, Strober M, Thornton LM, Treasure J, Woodside DB, Knight J, Kennedy JL. The role of leptin, melanocortin, and neurotrophin system genes on body weight in anorexia nervosa and bulimia nervosa. J Psychiatr Res 2014; 55:77-86. [PMID: 24831852 PMCID: PMC4191922 DOI: 10.1016/j.jpsychires.2014.04.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 03/05/2014] [Accepted: 04/04/2014] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Although low weight is a key factor contributing to the high mortality in anorexia nervosa (AN), it is unclear how AN patients sustain low weight compared with bulimia nervosa (BN) patients with similar psychopathology. Studies of genes involved in appetite and weight regulation in eating disorders have yielded variable findings, in part due to small sample size and clinical heterogeneity. This study: (1) assessed the role of leptin, melanocortin, and neurotrophin genetic variants in conferring risk for AN and BN; and (2) explored the involvement of these genes in body mass index (BMI) variations within AN and BN. METHOD Our sample consisted of 745 individuals with AN without a history of BN, 245 individuals with BN without a history of AN, and 321 controls. We genotyped 20 markers with known or putative function among genes selected from leptin, melanocortin, and neurotrophin systems. RESULTS There were no significant differences in allele frequencies among individuals with AN, BN, and controls. AGRP rs13338499 polymorphism was associated with lowest illness-related BMI in those with AN (p = 0.0013), and NTRK2 rs1042571 was associated with highest BMI in those with BN (p = 0.0018). DISCUSSION To our knowledge, this is the first study to address the issue of clinical heterogeneity in eating disorder genetic research and to explore the role of known or putatively functional markers in genes regulating appetite and weight in individuals with AN and BN. If replicated, our results may serve as an important first step toward gaining a better understanding of weight regulation in eating disorders.
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Affiliation(s)
- Zeynep Yilmaz
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Clinical Research Department, Centre for Addiction and Mental Health, Toronto, Canada
| | - Allan S Kaplan
- Clinical Research Department, Centre for Addiction and Mental Health, Toronto, Canada; Institute of Medical Science, University of Toronto, Toronto, Canada; Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Arun K Tiwari
- Neurogenetics Section, Centre for Addiction and Mental Health, Toronto, Canada
| | - Robert D Levitan
- Institute of Medical Science, University of Toronto, Toronto, Canada; Department of Psychiatry, University of Toronto, Toronto, Canada; Mood and Anxiety Program, Centre for Addiction and Mental Health, Toronto, Canada
| | - Sara Piran
- Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Andrew W Bergen
- Center for Health Sciences, SRI International, Menlo Park, CA, USA
| | - Walter H Kaye
- Department of Psychiatry, University of California, San Diego, CA, USA
| | - Hakon Hakonarson
- Joseph Stokes Jr. Research Institute, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kai Wang
- Department of Psychiatry, University of Southern California, Los Angeles, CA, USA
| | - Wade H Berrettini
- Department of Psychiatry, Center of Neurobiology and Behavior, University of Pennsylvania, Philadelphia, PA, USA
| | - Harry A Brandt
- Department of Psychiatry, Sheppard Pratt Health System, Towson, MD, USA
| | - Cynthia M Bulik
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Steven Crawford
- Department of Psychiatry, Sheppard Pratt Health System, Towson, MD, USA
| | - Scott Crow
- Department of Psychiatry, University of Minnesota, Minneapolis, MN, USA
| | - Manfred M Fichter
- Department of Psychiatry, University of Munich (LMU), Munich, Germany; Roseneck Hospital for Behavioral Medicine, Prien, Germany
| | - Katherine A Halmi
- Department of Psychiatry, Weill Cornell Medical College, New York, NY, USA
| | | | - Pamela K Keel
- Department of Psychology, Florida State University, Tallahassee, FL, USA
| | - Kelly L Klump
- Department of Psychology, Michigan State University, East Lansing, MI, USA
| | - Pierre Magistretti
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - James E Mitchell
- Department of Clinical Neuroscience, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, USA; Neuropsychiatric Research Institute, Fargo, ND, USA
| | - Michael Strober
- Department of Psychiatry, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Laura M Thornton
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Janet Treasure
- Department of Academic Psychiatry, King's College London, Institute of Psychiatry, London, United Kingdom
| | - D Blake Woodside
- Department of Psychiatry, University of Toronto, Toronto, Canada; Eating Disorders Program, Toronto General Hospital, Toronto, Canada
| | - Joanne Knight
- Institute of Medical Science, University of Toronto, Toronto, Canada; Department of Psychiatry, University of Toronto, Toronto, Canada; Neurogenetics Section, Centre for Addiction and Mental Health, Toronto, Canada
| | - James L Kennedy
- Institute of Medical Science, University of Toronto, Toronto, Canada; Department of Psychiatry, University of Toronto, Toronto, Canada; Neurogenetics Section, Centre for Addiction and Mental Health, Toronto, Canada.
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29
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Chowdhury TG, Ríos MB, Chan TE, Cassataro DS, Barbarich-Marsteller NC, Aoki C. Activity-based anorexia during adolescence disrupts normal development of the CA1 pyramidal cells in the ventral hippocampus of female rats. Hippocampus 2014; 24:1421-9. [PMID: 24976385 DOI: 10.1002/hipo.22320] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Revised: 05/22/2014] [Accepted: 06/19/2014] [Indexed: 12/22/2022]
Abstract
Anorexia nervosa (AN) is a psychiatric illness characterized by restricted eating and irrational fears of gaining weight. There is no accepted pharmacological treatment for AN, and AN has the highest mortality rate among psychiatric illnesses. Anorexia nervosa most commonly affects females during adolescence, suggesting an effect of sex and hormones on vulnerability to the disease. Activity-based anorexia (ABA) is a rodent model of AN that shares symptoms with AN, including over-exercise, elevation of stress hormones, and genetic links to anxiety traits. We previously reported that ABA in adolescent female rats results in increased apical dendritic branching in CA1 pyramidal cells of the ventral hippocampus at postnatal day 44 (P44). To examine the long-term effects of adolescent ABA (P44) in female rats, we compared the apical branching in the ventral hippocampal CA1 after recovery from ABA (P51) and after a relapse of ABA (P55) with age-matched controls. To examine the age-dependence of the hippocampal plasticity, we examined the effect of ABA during adulthood (P67). We found that while ABA at P44 resulted in increased branching of ventral hippocampal pyramidal cells, relapse of ABA at P55 resulted in decreased branching. ABA induced during adulthood did not have an effect on dendritic branching, suggesting an age-dependence of the vulnerability to structural plasticity. Cells from control animals were found to exhibit a dramatic increase in branching, more than doubling from P44 to P51, followed by pruning from P51 to P55. The proportion of mature spines on dendrites from the P44-ABA animals is similar to that on dendrites from P55-CON animals. These results suggest that the experience of ABA may cause precocious anatomical development of the ventral hippocampus. Importantly, we found that adolescence is a period of continued development of the hippocampus, and increased vulnerability to mental disorders during adolescence may be due to insults during this developmentally critical period.
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Affiliation(s)
- Tara G Chowdhury
- Center for Neural Science, New York University, New York, New York
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Aoki C, Wable G, Chowdhury TG, Sabaliauskas NA, Laurino K, Barbarich-Marsteller NC. α4βδ-GABAARs in the hippocampal CA1 as a biomarker for resilience to activity-based anorexia. Neuroscience 2014; 265:108-23. [PMID: 24444828 PMCID: PMC3996507 DOI: 10.1016/j.neuroscience.2014.01.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 12/09/2013] [Accepted: 01/07/2014] [Indexed: 12/01/2022]
Abstract
Anorexia nervosa (AN) is a psychiatric illness characterized by restricted eating and an intense fear of gaining weight. Most individuals with AN are females, diagnosed first during adolescence, 40-80% of whom exhibit excessive exercise, and an equally high number with a history of anxiety disorder. We sought to determine the cellular basis for individual differences in AN vulnerability by using an animal model, activity-based anorexia (ABA), that is induced by combining food restriction (FR) with access to a running wheel that allows voluntary exercise. Previously, we showed that by the fourth day of FR, the ABA group of adolescent female rats exhibit >500% greater levels of non-synaptic α4βδ-GABAARs at the plasma membrane of hippocampal CA1 pyramidal cell spines, relative to the levels found in age-matched controls that are not FR and without wheel access. Here, we show that the ABA group exhibits individual differences in body weight loss, with some losing nearly 30%, while others lose only 15%. The individual differences in weight loss are ascribable to individual differences in wheel activity that both precedes and concurs with days of FR. Moreover, the increase in activity during FR correlates strongly and negatively with α4βδ-GABAAR levels (R=-0.9, p<0.01). This negative correlation is evident within 2days of FR, before body weight loss approaches life-threatening levels for any individual. These findings suggest that increased shunting inhibition by α4βδ-GABAARs in spines of CA1 pyramidal neurons may participate in the protection against the ABA-inducing environmental factors of severe weight loss by suppressing excitability of the CA1 pyramidal neurons which, in turn, is related indirectly to suppression of excessive exercise. The data also indicate that, although exercise has many health benefits, it can be maladaptive to individuals with low levels of α4βδ-GABAARs in the CA1, particularly when combined with FR.
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Affiliation(s)
- C Aoki
- Center for Neural Science, New York University, New York, NY 10003, United States.
| | - G Wable
- Center for Neural Science, New York University, New York, NY 10003, United States
| | - T G Chowdhury
- Center for Neural Science, New York University, New York, NY 10003, United States
| | - N A Sabaliauskas
- Center for Neural Science, New York University, New York, NY 10003, United States
| | - K Laurino
- Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York, NY 10032, United States; Department of Psychiatry, New York State Psychiatric Institute, New York, NY 10032, United States
| | - N C Barbarich-Marsteller
- Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York, NY 10032, United States; Department of Psychiatry, New York State Psychiatric Institute, New York, NY 10032, United States
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Carrera O, Fraga Á, Pellón R, Gutiérrez E. Rodent model of activity-based anorexia. CURRENT PROTOCOLS IN NEUROSCIENCE 2014; 67:9.47.1-9.47.11. [PMID: 24723321 DOI: 10.1002/0471142301.ns0947s67] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Activity-based anorexia (ABA) consists of a procedure that involves the simultaneous exposure of animals to a restricted feeding schedule, while free access is allowed to an activity wheel. Under these conditions, animals show a progressive increase in wheel running, a reduced efficiency in food intake to compensate for their increased activity, and a severe progression of weight loss. Due to the parallelism with the clinical manifestations of anorexia nervosa including increased activity, reduced food intake and severe weight loss, the ABA procedure has been proposed as the best analog of human anorexia nervosa (AN). Thus, ABA research could both allow a better understanding of the mechanisms underlying AN and generate useful leads for treatment development in AN.
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Affiliation(s)
- Olaia Carrera
- Unidade Venres Clinicos, Universidad de Santiago de Compostela, Galicia, Spain
| | - Ángela Fraga
- Unidade Venres Clinicos, Universidad de Santiago de Compostela, Galicia, Spain
| | - Ricardo Pellón
- Departamento de Psicología Básica I, Facultad de Psicología, Universidad Nacional de Educación a Distancia, Madrid, Spain
| | - Emilio Gutiérrez
- Unidade Venres Clinicos, Universidad de Santiago de Compostela, Galicia, Spain
- Departamento de Psicología Clínica y Psicobiología, Universidad de Santiago de Compostela, Galicia, Spain
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WABLE GAURIS, BARBARICH-MARSTELLER NICOLEC, CHOWDHURY TARAG, SABALIAUSKAS NICOLEA, FARB CLAUDIAR, AOKI CHIYE. Excitatory synapses on dendritic shafts of the caudal basal amygdala exhibit elevated levels of GABAA receptor α4 subunits following the induction of activity-based anorexia. Synapse 2014; 68:1-15. [PMID: 23766101 PMCID: PMC4111138 DOI: 10.1002/syn.21690] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 06/03/2013] [Indexed: 12/26/2022]
Abstract
Anorexia nervosa (AN) is an eating disorder characterized by self-imposed severe starvation, excessive exercise, and anxiety. The onset of AN is most often at puberty, suggesting that gonadal hormonal fluctuations may contribute to AN vulnerability. Activity-based anorexia (ABA) is an animal model that reproduces some of the behavioral phenotypes of AN, including the paradoxical increase in voluntary exercise following food restriction. The basal amygdala as well as the GABAergic system regulate trait anxiety. We therefore examined the subcellular distribution of GABA receptors (GABARs) in the basal amygdala of female pubertal rats and specifically of their α4 subunits, because expression of α4-containing GABARs is regulated by gonadal hormone fluctuations. Moreover, because these GABARs reduce neuronal excitability through shunting of EPSPs, we quantified the frequency of occurrence of these GABARs adjacent to excitatory synapses. Electron microscopic immunoctychemistry revealed no change in the frequency of association of α4 subunits with excitatory synapses on dendritic spines, whether in the anterior (Bregma -2.8 mm) or caudal (Bregma -3.8 mm) portion of the basal amygdala. Sholl analysis of golgi-stained neurons also revealed no change in the extent of dendritic branching by these densely spiny, pyramidal-like neurons. However, there was an increase of membranous α4 subunits near excitatory synapses on dendritic shafts, specifically in the caudal basal amygdala, and this was accompanied by a rise of α4 subunits intracellularly. Because most dendritic shafts exhibiting excitatory synapses are GABAergic interneurons, the results predict disinhibition, which would increase excitability of the amygdaloid network, in turn augmenting ABA animals' anxiety.
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Affiliation(s)
- GAURI S. WABLE
- Center for Neural Science, New York University, New York, New York
| | - NICOLE C. BARBARICH-MARSTELLER
- Deartment of Psychiatry, College of Physicians & Surgeons of Columbia University, New York, New York
- Eating Disorder Research Unit, New York State Psychiatric Institute, New York, New York
| | | | | | - CLAUDIA R. FARB
- Center for Neural Science, New York University, New York, New York
| | - CHIYE AOKI
- Center for Neural Science, New York University, New York, New York
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Abstract
Disordered eating behavior is the core symptom of the complex disorders anorexia nervosa and bulimia nervosa. Twin and family studies derive high heritability estimates. Hence, substantial genetic influences on the etiology can be assumed for both. Initially, candidate gene studies pertaining to the monoaminergic neurotransmitter systems and to body weight regulation comprised the core of the genetic analyses. Unfortunately, confirmed, solid findings substantiated in meta-analyses are rare, so that eventually none of these associations is unequivocal. Thus, systematic, genome-wide approaches emerged to identify genes with no a priori evidence for their involvement in eating disorders. Genome-wide association studies have hinted to formerly unknown genetic regions. However, significant genome-wide findings have not yet been reported.
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A central role for C1q/TNF-related protein 13 (CTRP13) in modulating food intake and body weight. PLoS One 2013; 8:e62862. [PMID: 23638159 PMCID: PMC3636217 DOI: 10.1371/journal.pone.0062862] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 03/26/2013] [Indexed: 11/19/2022] Open
Abstract
C1q/TNF-related protein 13 (CTRP13), a hormone secreted by adipose tissue (adipokines), helps regulate glucose metabolism in peripheral tissues. We previously reported that CTRP13 expression is increased in obese and hyperphagic leptin-deficient mice, suggesting that it may modulate food intake and body weight. CTRP13 is also expressed in the brain, although its role in modulating whole-body energy balance remains unknown. Here, we show that CTRP13 is a novel anorexigenic factor in the mouse brain. Quantitative PCR demonstrated that food restriction downregulates Ctrp13 expression in mouse hypothalamus, while high-fat feeding upregulates expression. Central administration of recombinant CTRP13 suppressed food intake and reduced body weight in mice. Further, CTRP13 and the orexigenic neuropeptide agouti-related protein (AgRP) reciprocally regulate each other's expression in the hypothalamus: central delivery of CTRP13 suppressed Agrp expression, while delivery of AgRP increased Ctrp13 expression. Food restriction alone reduced Ctrp13 and increased orexigenic neuropeptide gene (Npy and Agrp) expression in the hypothalamus; in contrast, when food restriction was coupled to enhanced physical activity in an activity-based anorexia (ABA) mouse model, hypothalamic expression of both Ctrp13 and Agrp were upregulated. Taken together, these results suggest that CTRP13 and AgRP form a hypothalamic feedback loop to modulate food intake and that this neural circuit may be disrupted in an anorexic-like condition.
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Chowdhury TG, Wable GS, Sabaliauskas NA, Aoki C. Adolescent female C57BL/6 mice with vulnerability to activity-based anorexia exhibit weak inhibitory input onto hippocampal CA1 pyramidal cells. Neuroscience 2013; 241:250-67. [PMID: 23523748 DOI: 10.1016/j.neuroscience.2013.03.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 03/01/2013] [Accepted: 03/02/2013] [Indexed: 01/10/2023]
Abstract
Anorexia nervosa (AN) is an eating disorder characterized by self-imposed severe starvation and often linked with excessive exercise. Activity-based anorexia (ABA) is an animal model that reproduces some of the behavioral phenotypes of AN, including the paradoxical increase in voluntary exercise following food restriction (FR). Although certain rodents have been used successfully in this animal model, C57BL/6 mice are reported to be less susceptible to ABA. We re-examined the possibility that female C57BL/6 mice might exhibit ABA vulnerability during adolescence, the developmental stage/sex among the human population with particularly high AN vulnerability. After introducing the running wheel to the cage for 3 days, ABA was induced by restricting food access to 1h per day (ABA1, N=13) or 2 h per day (ABA2, N=10). All 23 exhibited increased voluntary wheel running (p<0.005) and perturbed circadian rhythm within 2 days. Only one out of five survived ABA1 for 3 days, while 10 out of 10 survived ABA2 for 3 days and could subsequently restore their body weight and circadian rhythm. Exposure of recovered animals to a second ABA2 induction revealed a large range of vulnerability, even within littermates. To look for the cellular substrate of differences in vulnerability, we began by examining synaptic patterns in the hippocampus, a brain region that regulates anxiety as well as plasticity throughout life. Quantitative EM analysis revealed that CA1 pyramidal cells of animals vulnerable to the second ABA2 exhibit less GABAergic innervation on cell bodies and dendrites, relative to the animals resilient to the second ABA (p<0.001) or controls (p<0.05). These findings reveal that C57BL/6J adolescent females can be used to capture brain changes underlying ABA vulnerability, and that GABAergic innervation of hippocampal pyramidal neurons is one important cellular substrate to consider for understanding the progression of and resilience to AN.
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Monteleone P, Maj M. Dysfunctions of leptin, ghrelin, BDNF and endocannabinoids in eating disorders: beyond the homeostatic control of food intake. Psychoneuroendocrinology 2013; 38:312-30. [PMID: 23313276 DOI: 10.1016/j.psyneuen.2012.10.021] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 10/29/2012] [Accepted: 10/29/2012] [Indexed: 12/18/2022]
Abstract
A large body of literature documents the occurrence of alterations in the physiology of both central and peripheral modulators of appetite in acute patients with anorexia nervosa (AN) and bulimia nervosa (BN). Until more recently the role of most of the appetite modulators in the control of eating behavior was conceptualized solely in terms of their influence on homeostatic control of energy balance. However, it is becoming more and more evident that appetite modulators also affect the non-homeostatic cognitive, emotional and rewarding component of food intake as well as non food-related reward, and, recently, AN and BN have been pathophysiologically linked to dysfunctions of reward mechanisms. Therefore, the possibility exists that observed changes in appetite modulators in acute AN and BN may represent not only homeostatic adaptations to malnutrition, but also contribute to the development and/or the maintenance of aberrant non-homeostatic behaviors, such as self-starvation and binge eating. In the present review, the evidences supporting a role of leptin, ghrelin, brain-derived neurotrophic factor and endocannabinoids in the homeostatic and non-homeostatic dysregulations of patients with AN and BN will be presented. The reviewed literature is highly suggestive that changes in the physiology of these modulators may play a pivotal role in the pathophysiology of eating disorders by providing a possible link between motivated behaviors, reward processes, cognitive functions and energy balance.
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Affiliation(s)
- Palmiero Monteleone
- Department of Medicine and Surgery, University of Salerno, via S. Allende, 84084 Baronissi (Salerno), Italy.
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Klinker F, Hasan K, Paulus W, Nitsche MA, Liebetanz D. Pharmacological blockade and genetic absence of the dopamine D2 receptor specifically modulate voluntary locomotor activity in mice. Behav Brain Res 2013; 242:117-24. [PMID: 23291158 DOI: 10.1016/j.bbr.2012.12.038] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Revised: 12/21/2012] [Accepted: 12/24/2012] [Indexed: 11/29/2022]
Abstract
Dopaminergic signaling influences physical activity. Notably impaired D2 receptor (D2R) function has been associated with decreased voluntary physical activity. Most animal models investigating effects of genetic or pharmacological dopaminergic modulation measure physical activity for a limited time of up to few hours. The aim of this study is to investigate the impact of chronic or acute D2R dysfunction on physical activity over several days. For this purpose, we used a highly automated running wheel system to continuously record physical activity in mice. We found that D2R-knockout status led to a permanent decrease of running wheel activity. In contrast, acute D2R blockade by raclopride (1.5-5mg/kg) resulted in an initial dose-dependent reduction of running wheel usage and a compensating increase of activity in later stages of the activity phase. This indicates that D2R dysfunction reduces physical activity. Our data indicate that this reduction to a large extent cannot be explained by motor deficits. The delayed increase of activity after D2R blockade might be due to a rebound effect.
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Affiliation(s)
- Florian Klinker
- Clinical Neurophysiology, University Medical Centre, Georg-August-University, Göttingen, Germany.
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Merkestein M, Verhagen LAW, Adan RAH. Food-Anticipatory Activity: Rat Models and Underlying Mechanisms. NEUROMETHODS 2013. [DOI: 10.1007/978-1-62703-104-2_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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40
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Identifying predictors of activity based anorexia susceptibility in diverse genetic rodent populations. PLoS One 2012; 7:e50453. [PMID: 23226287 PMCID: PMC3511580 DOI: 10.1371/journal.pone.0050453] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 10/22/2012] [Indexed: 11/19/2022] Open
Abstract
Animal studies are very useful in detection of early disease indicators and in unravelling the pathophysiological processes underlying core psychiatric disorder phenotypes. Early indicators are critical for preventive and efficient treatment of progressive psychiatric disorders like anorexia nervosa. Comparable to physical hyperactivity observed in anorexia nervosa patients, in the activity-based anorexia rodent model, mice and rats express paradoxical high voluntary wheel running activity levels when food restricted. Eleven inbred mouse strains and outbred Wistar WU rats were exposed to the activity-based anorexia model in search of identifying susceptibility predictors. Body weight, food intake and wheel running activity levels of each individual mouse and rat were measured. Mouse strains and rats with high wheel running activity levels during food restriction exhibited accelerated body weight loss. Linear mixed models for repeated measures analysis showed that baseline wheel running activity levels preceding the scheduled food restriction phase strongly predicted activity-based anorexia susceptibility (mice: Beta = −0.0158 (±0.003 SE), P<0.0001; rats: Beta = −0.0242 (±0.004 SE), P<0.0001) compared to other baseline parameters. These results suggest that physical activity levels play an important role in activity-based anorexia susceptibility in different rodent species with genetically diverse background. These findings support previous retrospective studies on physical activity levels in anorexia nervosa patients and indicate that pre-morbid physical activity levels could reflect an early indicator for disease severity.
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Carrera O, Adan RAH, Gutierrez E, Danner UN, Hoek HW, van Elburg AA, Kas MJH. Hyperactivity in anorexia nervosa: warming up not just burning-off calories. PLoS One 2012; 7:e41851. [PMID: 22848634 PMCID: PMC3407098 DOI: 10.1371/journal.pone.0041851] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Accepted: 06/29/2012] [Indexed: 02/03/2023] Open
Abstract
Excessive physical activity is a common feature in Anorexia Nervosa (AN) that interferes with the recovery process. Animal models have demonstrated that ambient temperature modulates physical activity in semi-starved animals. The aim of the present study was to assess the effect of ambient temperature on physical activity in AN patients in the acute phase of the illness. Thirty-seven patients with AN wore an accelerometer to measure physical activity within the first week of contacting a specialized eating disorder center. Standardized measures of anxiety, depression and eating disorder psychopathology were assessed. Corresponding daily values for ambient temperature were obtained from local meteorological stations. Ambient temperature was negatively correlated with physical activity (p = −.405) and was the only variable that accounted for a significant portion of the variance in physical activity (p = .034). Consistent with recent research with an analogous animal model of the disorder, our findings suggest that ambient temperature is a critical factor contributing to the expression of excessive physical activity levels in AN. Keeping patients warm may prove to be a beneficial treatment option for this symptom.
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Affiliation(s)
- Olaia Carrera
- Department of Neuroscience & Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
- Altrecht Eating Disorders Rintveld, Altrecht Mental Health Institute, Zeist, The Netherlands
- Departamento de Psicologia Clinica y Psicobiologia, y Unidad Venres Clinicos Facultad de Psicologia, Universidad de Santiago de Compostela, Campus Vida, Santiago de Compostela, Spain
- Complejo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain
- Utrecht Research Group Eating Disorders, Utrecht, The Netherlands
| | - Roger A. H. Adan
- Department of Neuroscience & Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
- Altrecht Eating Disorders Rintveld, Altrecht Mental Health Institute, Zeist, The Netherlands
- Utrecht Research Group Eating Disorders, Utrecht, The Netherlands
| | - Emilio Gutierrez
- Departamento de Psicologia Clinica y Psicobiologia, y Unidad Venres Clinicos Facultad de Psicologia, Universidad de Santiago de Compostela, Campus Vida, Santiago de Compostela, Spain
| | - Unna N. Danner
- Altrecht Eating Disorders Rintveld, Altrecht Mental Health Institute, Zeist, The Netherlands
- Utrecht Research Group Eating Disorders, Utrecht, The Netherlands
| | - Hans W. Hoek
- Department of Neuroscience & Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
- Utrecht Research Group Eating Disorders, Utrecht, The Netherlands
- Parnassia Bavo Psychiatric Institute, The Hague, The Netherlands
- Department of Psychiatry, Groningen University Medical Center, Groningen, The Netherlands
- Department of Epidemiology, Columbia University, New York, New York, United States of America
| | - Annemarie A. van Elburg
- Altrecht Eating Disorders Rintveld, Altrecht Mental Health Institute, Zeist, The Netherlands
- Utrecht Research Group Eating Disorders, Utrecht, The Netherlands
| | - Martien J. H. Kas
- Department of Neuroscience & Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
- Utrecht Research Group Eating Disorders, Utrecht, The Netherlands
- * E-mail:
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Olanzapine, but not fluoxetine, treatment increases survival in activity-based anorexia in mice. Neuropsychopharmacology 2012; 37:1620-31. [PMID: 22395732 PMCID: PMC3358753 DOI: 10.1038/npp.2012.7] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Anorexia nervosa (AN) is an eating disorder characterized by extreme hypophagia, hyperactivity, and fear of weight gain. No approved pharmacological treatments exist for AN despite high mortality rates. The activity-based anorexia (ABA) phenomenon models aspects of AN in rodents, including progressive weight loss, reduced food intake, and hyperactivity. First, we optimized the ABA paradigm for mice. We compared mouse strains (Balb/cJ, A/J) for susceptibility with ABA, and evaluated the effects of different food access durations (2, 4, 6, 8, and 10 h) on ABA parameters. Balb/cJ mice exhibited significantly shorter survival time (days until 25% bodyweight loss) in the ABA paradigm compared with A/J mice. Furthermore, 6 h of food access reduced survival in mice housed with wheels without reducing survival in mice housed without wheels. We then evaluated the effects of chronic treatment with fluoxetine (4 weeks) or subchronic treatment with olanzapine (OLZ) (1 week) on ABA in BALB/cJ mice. OLZ (12 mg/kg/day) significantly increased survival and reduced food anticipatory activity (FAA). However, OLZ did not alter food intake or running wheel activity during ad-lib feeding (baseline) or restriction conditions, or in mice housed without wheels. Fluoxetine (18 mg/kg/day) increased food intake and reduced FAA, but did not alter survival. Here, we report for the first time that OLZ, but not fluoxetine, reduces ABA in mice. Our findings indicate further need for clinical investigations into the effects of OLZ, but not selective serotonin reuptake inhibitors, on core features of AN.
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Aoki C, Sabaliauskas N, Chowdhury T, Min JY, Colacino AR, Laurino K, Barbarich-Marsteller NC. Adolescent female rats exhibiting activity-based anorexia express elevated levels of GABA(A) receptor α4 and δ subunits at the plasma membrane of hippocampal CA1 spines. Synapse 2012; 66:391-407. [PMID: 22213233 DOI: 10.1002/syn.21528] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 12/06/2011] [Accepted: 12/14/2011] [Indexed: 12/26/2022]
Abstract
Activity-based anorexia (ABA) is an animal model for anorexia nervosa that has revealed genetic links to anxiety traits and neurochemical characteristics within the hypothalamus. However, few studies have used this animal model to investigate the biological basis for vulnerability of pubertal and adolescent females to ABA, even though the great majority of the anorexia nervosa cases are females exhibiting the first symptoms during puberty. GABAergic inhibition of the hippocampus strongly regulates anxiety as well as plasticity throughout life. We recently showed that the hippocampal CA1 of female mice undergo a dramatic change at puberty onset--from expressing virtually none of the nonsynaptic α4βδ GABA(A) receptors (GABARs) prepubertally to expressing these GABARs at ~7% of the CA1 dendritic spine membranes at puberty onset. Furthermore, we showed that this change underlies the enhanced modulation of anxiety, neuronal excitability, and NMDA receptor-dependent synaptic plasticity in the hippocampus by the stress neurosteroid, THP (3α-OH-5α[β]-pregnan-20-one or [allo]pregnanolone). Here, we used quantitative electron microscopy to determine whether ABA induction in female rats during adolescence also elevates the expression of α4 and δ subunits of α4βδ GABARs, as was observed at puberty onset for mice. Our analysis revealed that rats also exhibit a rise of α4 and δ subunits of α4βδ GABARs at puberty onset, in that these subunits are detectable at ~6% of the dendritic spine membranes of CA1 pyramidal cells at puberty onset (postnatal day 32-36; P32-36) but this drops to about 2% by P40-P44. The levels of α4 and δ subunits at the CA1 spines remained low following exposure of females to either of the two environmental factors needed to generate ABA--food restriction and access to a running wheel for 4 days--from P40 to P44. This pattern contrasted greatly from those of ABA animals, for which the two environmental factors were combined. Within the hippocampus of ABA animals, 12% of the spine profiles were labeled for α4, reflecting a sixfold increase, relative to hippocampi of age-matched (P44) control females (p < 0.005). Concurrently, 7% of the spine profiles were labeled for δ, reflecting a 130% increase from the control values of 3% (p = 0.01). No measurable change was detected for spine size. The observed magnitude of increase in the α4 and δ subunits at spines is sufficient to increase both tonic inhibition of hippocampus and anxiety during stress, thereby likely to exacerbate hyperactivity and weight loss.
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Affiliation(s)
- Chiye Aoki
- Center for Neural Science, New York University, New York, New York 10003, USA.
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Chou CJ, Affolter M, Kussmann M. A Nutrigenomics View of Protein Intake. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 108:51-74. [DOI: 10.1016/b978-0-12-398397-8.00003-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Abstract
Animals housed with running wheels and subjected to daily food restriction show paradoxical reductions in food intake and increases in running wheel activity. This phenomenon, known as activity-based anorexia (ABA), leads to marked reductions in body weight that can ultimately lead to death. Recently, ABA has been proposed as a model of anorexia nervosa (AN). AN affects about 8 per 100,000 females and has the highest mortality rate among all psychiatric illnesses. Given the reductions in quality of life, high mortality rate, and the lack of pharmacological treatments for AN, a better understanding of the mechanisms underlying AN-like behavior is greatly needed. This chapter provides basic guidelines for conducting ABA experiments using mice. The ABA mouse model provides an important tool for investigating the neurobiological underpinnings of AN-like behavior and identifying novel treatments.
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Pjetri E, Adan RA, Herzog H, de Haas R, Oppelaar H, Spierenburg HA, Olivier B, Kas MJ. NPY receptor subtype specification for behavioral adaptive strategies during limited food access. GENES BRAIN AND BEHAVIOR 2011; 11:105-12. [PMID: 21923762 DOI: 10.1111/j.1601-183x.2011.00732.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The neuropeptide Y (NPY) system in the brain regulates a wide variety of behavioral, metabolic and hormonal homeostatic processes required for energy balance control. During times of limited food availability, NPY promotes behavioral hyperactivity necessary to explore and prepare for novel food resources. As NPY can act via 5 different receptor subtypes, we investigated the path through which NPY affects different behavioral components relevant for adaptation to such conditions. We tested NPY Y1 and Y2 receptor knockout mice and their wild-type littermate controls in a daily scheduled limited food access paradigm with unlimited access to running wheel. Here we show that NPY Y1 receptor deficient mice lack the expression of appetitive behavior and that NPY Y2 receptors control the level of hyperactive behavior under these conditions. Thus, receptor specificity determines the differential expression of NPY-mediated behavioral adaptations to overcome a negative energy status.
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Affiliation(s)
- E Pjetri
- Rudolf Magnus Institute of Neuroscience, Department of Neuroscience and Pharmacology, University Medical Centre Utrecht, Utrecht, The Netherlands
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Brandys MK, Kas MJH, van Elburg AA, Campbell IC, Adan RAH. A meta-analysis of circulating BDNF concentrations in anorexia nervosa. World J Biol Psychiatry 2011; 12:444-54. [PMID: 21486106 DOI: 10.3109/15622975.2011.562244] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVES Brain derived neurotrophic factor (BDNF) is involved in neuroplasticity, and in the homeostatic regulation of food intake and energy expenditure. It also has a role in stress responsivity and reward processing. On the basis of its involvement in these various processes, BDNF can be hypothesized to be an important factor in the development and maintenance of anorexia nervosa (AN). This study meta-analytically summarizes investigations of serum BDNF concentrations in people currently ill with AN, in comparison to healthy controls. METHODS Seven studies measuring BDNF in serum of individuals with AN (n=155) and healthy controls (n=174) were identified and included in the meta-analysis of the mean differences between case and control groups. RESULTS This study confirms that AN is associated with decreased serum BDNF concentrations, in comparison to healthy controls. The combined effect size (standardized mean difference, SMD) was large (SMD=-0.96; 95% CI -1.33 to -0.59; P<0.001). Significant heterogeneity of effect sizes was identified (I(2)=58.3%; P<0.001), which emerged as being primarily attributable to the first published study on the investigated association. CONCLUSIONS The present meta-analytical summary of studies measuring circulating BDNF concentrations in women with AN and healthy controls confirms that it is significantly reduced in this patient group. Difficulties associated with the measurement of BDNF have been identified and potential confounding factors have been discussed. Current data do not allow inferences to be made about causal links between levels of circulating BDNF and AN. However, possible explanations for the relationship between BDNF and AN have been presented.
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Affiliation(s)
- Marek K Brandys
- Department of Neuroscience & Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Centre Utrecht, Utrecht, The Netherlands
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Noble EE, Billington CJ, Kotz CM, Wang C. The lighter side of BDNF. Am J Physiol Regul Integr Comp Physiol 2011; 300:R1053-69. [PMID: 21346243 DOI: 10.1152/ajpregu.00776.2010] [Citation(s) in RCA: 201] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) mediates energy metabolism and feeding behavior. As a neurotrophin, BDNF promotes neuronal differentiation, survival during early development, adult neurogenesis, and neural plasticity; thus, there is the potential that BDNF could modify circuits important to eating behavior and energy expenditure. The possibility that "faulty" circuits could be remodeled by BDNF is an exciting concept for new therapies for obesity and eating disorders. In the hypothalamus, BDNF and its receptor, tropomyosin-related kinase B (TrkB), are extensively expressed in areas associated with feeding and metabolism. Hypothalamic BDNF and TrkB appear to inhibit food intake and increase energy expenditure, leading to negative energy balance. In the hippocampus, the involvement of BDNF in neural plasticity and neurogenesis is important to learning and memory, but less is known about how BDNF participates in energy homeostasis. We review current research about BDNF in specific brain locations related to energy balance, environmental, and behavioral influences on BDNF expression and the possibility that BDNF may influence energy homeostasis via its role in neurogenesis and neural plasticity.
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Affiliation(s)
- Emily E Noble
- Veterans Affairs Medical Center, GRECC 11G, One Veterans Drive, Minneapolis, MN, USA.
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Abstract
Eating disorders, such as anorexia and bulimia nervosa, are psychiatric disorders that are likely determined by a complex interaction between genetic variations, developmental processes, and certain life events. Cross-species analysis of traits related to eating disorders may provide a way to functionally and systematically study neurobiological mechanisms underlying these disorders. Interspecies trait genetics may offer opportunities to identify common neurobiological mechanisms underlying eating disorder characteristics relevant to the initiation, progression, and/or maintenance of the disease, such as cognitive rigidity, increased anxiety levels, and behavioral hyperactivity. These can subsequently be tested directly by studying allelic variation in mice and human subjects and by applying methods that can modify gene expression levels in rodent models. Increasing our knowledge about these traits and their underlying neurobiological mechanisms will be relevant to develop new therapies for patients within the heterogeneous eating disorder populations. Novel mouse genetic and phenotyping tools offer a way to study these neurobehavioral traits under controlled environmental and genetic background conditions.
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Affiliation(s)
- Martien J H Kas
- Department of Neuroscience and Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Centre Utrecht, The Netherlands.
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