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Brown RM, James MH. Binge eating, overeating and food addiction: Approaches for examining food overconsumption in laboratory rodents. Prog Neuropsychopharmacol Biol Psychiatry 2023; 123:110717. [PMID: 36623582 PMCID: PMC10162020 DOI: 10.1016/j.pnpbp.2023.110717] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 12/29/2022] [Accepted: 01/04/2023] [Indexed: 01/09/2023]
Abstract
Overeating ranges in severity from casual overindulgence to an overwhelming drive to consume certain foods. At its most extreme, overeating can manifest as clinical diagnoses such as binge eating disorder or bulimia nervosa, yet subclinical forms of overeating such as emotional eating or uncontrolled eating can still have a profoundly negative impact on health and wellbeing. Although rodent models cannot possibly capture the full spectrum of disordered overeating, studies in laboratory rodents have substantially progressed our understanding of the neurobiology of overconsumption. These experimental approaches range from simple food-exposure protocols that promote binge-like eating and the development of obesity, to more complex operant procedures designed to examine distinct 'addiction-like' endophenotypes for food. This review provides an overview of these experimental approaches, with the view to providing a comprehensive resource for preclinical investigators seeking to utilize behavioural models for studying the neural systems involved in food overconsumption.
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Affiliation(s)
- Robyn M Brown
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, VIC, Australia; Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia.
| | - Morgan H James
- Department of Psychiatry, Robert Wood Johnson Medical School, Rutgers University, NJ, USA; Brain Health Institute, Rutgers University, NJ, USA.
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Epstein LH, Carr KA. Food reinforcement and habituation to food are processes related to initiation and cessation of eating. Physiol Behav 2021; 239:113512. [PMID: 34217735 DOI: 10.1016/j.physbeh.2021.113512] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 05/25/2021] [Accepted: 06/28/2021] [Indexed: 01/11/2023]
Abstract
An individual bout of eating involves cues to start eating, as well as cues to terminate eating. One process that determines initiation of eating is food reinforcement. Foods with high reinforcing value are also likely to be consumed in greater quantities. Research suggests both cross-sectional and prospective relationships between food reinforcement and obesity, food reinforcement is positively related to energy intake, and energy intake mediates the relationship between food reinforcement and obesity. A process related to cessation of eating is habituation. Habituation is a general behavioral process that describes a reduction in physiological or affective response to a stimulus, or a reduction in the behavioral responding to obtain a stimulus. Repeated exposure to the same food during a meal can result in habituation to that food and a reduction in consumption. Habituation is also cross-sectionally and prospectively related to body weight, as people who habituate slower consume more in a meal and are more overweight. Research from our laboratory has shown that these two processes independently influence eating, as they can account for almost 60% of the variance in ad libitum intake. In addition, habituation phenotypes show reliable relationships with reinforcing value, such that people who habituate faster also find food less reinforcing. Developing a better understanding of cues to start and stop eating is fundamental to understanding how to modify eating behavior. An overview of research on food reinforcement, habituation and food intake for people with a range of weight status and without eating disorders is provided, and ideas about integrating these two processes that are related to initiation and termination of a bout of eating are discussed.
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Affiliation(s)
- Leonard H Epstein
- Jacobs School of Medicine and Biomedical Sciences, Department of Pediatrics, University at Buffalo, G56 Farber Hall, 3435 Main Street, Building #26, Buffalo, New York 14214-3000, USA.
| | - Katelyn A Carr
- Jacobs School of Medicine and Biomedical Sciences, Department of Pediatrics, University at Buffalo, G56 Farber Hall, 3435 Main Street, Building #26, Buffalo, New York 14214-3000, USA.
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Binge eating behavior and incentive motivation with a cafeteria diet. Behav Processes 2021; 190:104447. [PMID: 34174369 DOI: 10.1016/j.beproc.2021.104447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/21/2021] [Accepted: 06/19/2021] [Indexed: 11/21/2022]
Abstract
Binge-like eating behavior (BLE) has been characterized as an eating disorder in which subjects have an enhanced intake of food, mainly fats. However, intake of fats and carbohydrates may have differential effects on motivation. Previously it was shown that BLE produces an increase in operant responding for vegetable shortening, but others were unable to replicate the finding using sucrose as the reinforcer. Our aim was to determine if BLE behavior induced with a cafeteria-like diet (CaLD) with several options with fat content would produce an increment in performance. Male Wistar rats were trained under an exponential progressive ratio schedule of sucrose reinforcement; thereafter, the limited access model was used to induce BLE using CaLD options. Finally, subjects were tested for increments in break points (BPs) in the progressive ratio schedule. Rats with intermittent access to CaLD options showed a clear BLE with an escalation in their intake; however they showed compensatory decrements of chow intake that rendered a similar body weight gain to a continuous access group. Although we were unable to observe an increase in BPs after BLE we were able to observe a protection against the decrements of BP previously observed with sugar. Different mechanisms for processing high fat and high carbohydrate reinforcers are variables worth exploring to gain a better understanding of BLE behavior in rodent models.
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Jones SR, Fordahl SC. Bingeing on High-Fat Food Enhances Evoked Dopamine Release and Reduces Dopamine Uptake in the Nucleus Accumbens. Obesity (Silver Spring) 2021; 29:721-730. [PMID: 33660412 PMCID: PMC8048651 DOI: 10.1002/oby.23122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Binge-eating disorder (BED) disrupts dopamine neuron function, in part by altering dopamine transporter (DAT) activity. This study characterized the effects of high-fat bingeing on presynaptic dopamine terminals and tested the hypothesis that acute low-dose amphetamine would restore DAT function. METHODS C57BL/6 mice were given limited access (LimA) to a high-fat diet (2 h/d, 3 d/wk) or standard chow (control). After 6 weeks, ex vivo fast-scan cyclic voltammetry was used to characterize dopamine-terminal adaptations in the nucleus accumbens. Prior to undergoing fast-scan cyclic voltammetry, some mice from each group were given amphetamine (0.5 mg/kg intraperitoneally). RESULTS Escalation of high fat intake, termed bingeing, occurred in the LimA group and coincided with increased phasic dopamine release, reduced dopamine uptake rates, and increased dopamine receptor 2 (D2 ) autoreceptor function. Acute amphetamine selectively reversed dopamine uptake changes in the LimA group and restored the potency of amphetamine to inhibit uptake. CONCLUSIONS High-fat bingeing enhanced dopaminergic signaling in the nucleus accumbens by promoting phasic dopamine release and reducing clearance. This study's data show that amphetamine was efficacious in restoring impaired DAT function caused by high-fat bingeing but did not reduce dopamine release to normal. These presynaptic changes should be considered if amphetamine-like dopamine releasers are used as treatments for BED.
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Affiliation(s)
- Sara R. Jones
- Department of Physiology and PharmacologySchool of MedicineWake Forest UniversityWinston‐SalemNorth CarolinaUSA
| | - Steve C. Fordahl
- Department of NutritionUNC GreensboroGreensboroNorth CarolinaUSA
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Zepeda-Ruiz WA, Vazquez-Herrera NV, Velazquez-Martinez DN. Dissociation between binge eating behavior and incentive motivation. Behav Processes 2020; 181:104273. [PMID: 33068639 DOI: 10.1016/j.beproc.2020.104273] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 10/05/2020] [Accepted: 10/05/2020] [Indexed: 12/28/2022]
Abstract
Binge-like eating behavior (BLE) has been characterized as an eating disorder in which subjects have an enhanced intake of food, mainly fats. However, intake of fats and carbohydrates may have differential effects on motivation. Previously it was shown that BLE produces an increase in operant responding for vegetable shortening. Our aim was to determine if BLE behavior induced with a sucrose solution would produce an increment in performance for sucrose reinforcers. Male Wistar rats were trained under an exponential progressive ratio schedule of sucrose reinforcement; thereafter, the limited access model was used to induce BLE. Finally, subjects were tested for increments in break points (BPs) in the progressive ratio schedule. We were unable to observe an increase in BPs after BLE. No increments in BPs were observed when a distinctive flavor (vanilla-flavored sucrose) was correlated with BLE induction and reinforcement, or when different types of ratio progression in the operant schedules were employed. However, rats adjusted their BPs according to reinforcer concentration after BLE induction, demonstrating that valuation (cost/benefit decision) of reinforcers was intact. Extent of training, alterations of reward processing after extended exposure to sucrose, and different mechanisms for processing high fat and high carbohydrate reinforcers are variables worth exploring to gain a better understanding of BLE behavior in rodent models.
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Affiliation(s)
- Wendy Andrea Zepeda-Ruiz
- Departamento de Psicofisiolgía, Facultad de Psicología, Universidad Nacional Autónoma de México, Ciudad de México, 04369 Mexico
| | - Nayeli Valeria Vazquez-Herrera
- Departamento de Psicofisiolgía, Facultad de Psicología, Universidad Nacional Autónoma de México, Ciudad de México, 04369 Mexico
| | - David N Velazquez-Martinez
- Departamento de Psicofisiolgía, Facultad de Psicología, Universidad Nacional Autónoma de México, Ciudad de México, 04369 Mexico.
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Behavioral profile of intermittent vs continuous access to a high fat diet during adolescence. Behav Brain Res 2019; 368:111891. [PMID: 31009646 DOI: 10.1016/j.bbr.2019.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 03/13/2019] [Accepted: 04/03/2019] [Indexed: 12/28/2022]
Abstract
Over the past few years, the effects of a high-fat diet (HFD) on cognitive functions have been broadly studied as a model of obesity, although no studies have evaluated whether these effects are maintained after the cessation of this diet. In addition, the behavioral effects of having a limited access to an HFD (binge-eating pattern) are mostly unknown, although they dramatically increase the vulnerability to drug use in contrast to having continuous access. Thus, the aim of the present study was to compare the effects of an intermittent versus a continuous exposure to an HFD during adolescence on cognition and anxiety-like behaviors, as well as to study the changes observed after the interruption of this diet. Adolescent male mice received for 40 days a standard diet, an HFD with continuous access or an HFD with sporadic limited access (2 h, three days a week). Two additional groups were fed with intermittent or continuous access to the HFD and withdrawn from this diet 15 days before the behavioral tests. Only the animals with a continuous access to the HFD showed higher circulating leptin levels, increased bodyweight, marked memory and spatial learning deficits, symptoms that disappeared after 15 days of HFD abstinence. Mice that binged on fat only showed hyperlocomotion, which normalized after 15 days of HFD cessation. However, discontinuation of fat, either in a binge or a continuous pattern, led to an increase in anxiety-like behavior. These results highlight that exposure to a high-fat diet during adolescence induces alterations in brain functions, although the way in which this diet is ingested determines the extent of these behavioral changes.
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Binge-Type Eating in Rats is Facilitated by Neuromedin U Receptor 2 in the Nucleus Accumbens and Ventral Tegmental Area. Nutrients 2019; 11:nu11020327. [PMID: 30717427 PMCID: PMC6412951 DOI: 10.3390/nu11020327] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 01/29/2019] [Accepted: 01/30/2019] [Indexed: 12/26/2022] Open
Abstract
Binge-eating disorder (BED) is the most common eating disorder, characterized by rapid, recurrent overconsumption of highly palatable food in a short time frame. BED shares an overlapping behavioral phenotype with obesity, which is also linked to the overconsumption of highly palatable foods. The reinforcing properties of highly palatable foods are mediated by the nucleus accumbens (NAc) and the ventral tegmental area (VTA), which have been implicated in the overconsumption behavior observed in BED and obesity. A potential regulator of binge-type eating behavior is the G protein-coupled receptor neuromedin U receptor 2 (NMUR2). Previous research demonstrated that NMUR2 knockdown potentiates binge-type consumption of high-fat food. We correlated binge-type consumption across a spectrum of fat and carbohydrate mixtures with synaptosomal NMUR2 protein expression in the NAc and VTA of rats. Synaptosomal NMUR2 protein in the NAc demonstrated a strong positive correlation with binge intake of a “lower”-fat (higher carbohydrate) mixture, whereas synaptosomal NMUR2 protein in the VTA demonstrated a strong negative correlation with binge intake of an “extreme” high-fat (0% carbohydrate) mixture. Taken together, these data suggest that NMUR2 may differentially regulate binge-type eating within the NAc and the VTA.
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Smail-Crevier RL, Maracle AC, Wash SI, Olmstead MC. Binge-like intake of sucrose reduces the rewarding value of sucrose in adult rats. Physiol Behav 2018; 194:420-429. [DOI: 10.1016/j.physbeh.2018.06.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 06/18/2018] [Accepted: 06/18/2018] [Indexed: 12/16/2022]
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Blanco-Gandía MC, Montagud-Romero S, Aguilar MA, Miñarro J, Rodríguez-Arias M. Housing conditions modulate the reinforcing properties of cocaine in adolescent mice that binge on fat. Physiol Behav 2018; 183:18-26. [DOI: 10.1016/j.physbeh.2017.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 10/11/2017] [Accepted: 10/12/2017] [Indexed: 12/22/2022]
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Modeling hypohedonia following repeated social defeat: Individual vulnerability and dopaminergic involvement. Physiol Behav 2017; 177:99-106. [PMID: 28433467 DOI: 10.1016/j.physbeh.2017.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 03/17/2017] [Accepted: 04/18/2017] [Indexed: 11/20/2022]
Abstract
Social defeat in rodents putatively can model hypohedonia. The present studies examined models for assessing hypohedonia-like behavior and tested the hypotheses that 1) individual differences in baseline reward sensitivity predict vulnerability, and 2) defeat elicits changes in pharmacological measures of striatal dopaminergic function. Male Wistar rats (n=142) received repeated defeat (3 "triad" blocks of 3 defeats) or control handling. To determine whether defeat influenced consumption of SuperSac (glucose-saccharin) over an isocaloric, less preferred, glucose solution, a 2-choice paradigm was used. To determine repeated defeat effects on the reinforcing efficacy of SuperSac, a progressive-ratio schedule of reinforcement was used. Amphetamine-induced locomotor activity (0.08mg/kg, s.c.) was determined as a measure sensitive to striatal dopaminergic function. Defeat reduced SuperSac consumption during the first two triads-an effect seen in the third triad only in defeated rats with High vs. Low baseline SuperSac intake. The characteristic escalation in PR breakpoint for SuperSac normally seen in controls was absent in defeated rats, leading to a significant difference by the third triad. Defeat-induced blunting of the escalation in PR performance was greater in rats with High antecedent PR breakpoints and persisted 2.5weeks post-defeat. Repeated defeat also blunted amphetamine-induced locomotion 13days post-defeat. Thus, hypohedonic-like effects of social defeat were detected and accompanied by persistently attenuated striatal dopamine function. Early effects were seen for consumption of differentially-palatable solutions, and persistent effects were seen for the "breakpoint" motivational measure. The results implicate initial reward sensitivity as a risk factor for stress-induced hypohedonia.
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Blanco-Gandía MC, Cantacorps L, Aracil-Fernández A, Montagud-Romero S, Aguilar MA, Manzanares J, Valverde O, Miñarro J, Rodríguez-Arias M. Effects of bingeing on fat during adolescence on the reinforcing effects of cocaine in adult male mice. Neuropharmacology 2017; 113:31-44. [DOI: 10.1016/j.neuropharm.2016.09.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/12/2016] [Accepted: 09/21/2016] [Indexed: 01/27/2023]
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Eikelboom R, Hewitt R. Intermittent access to a sucrose solution for rats causes long-term increases in consumption. Physiol Behav 2016; 165:77-85. [DOI: 10.1016/j.physbeh.2016.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 06/28/2016] [Accepted: 07/05/2016] [Indexed: 10/21/2022]
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Corwin RLW, Wojnicki FHE, Zimmer DJ, Babbs RK, McGrath LE, Olivos DR, Mietlicki-Baase EG, Hayes MR. Binge-type eating disrupts dopaminergic and GABAergic signaling in the prefrontal cortex and ventral tegmental area. Obesity (Silver Spring) 2016; 24:2118-25. [PMID: 27558648 DOI: 10.1002/oby.21626] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 06/14/2016] [Accepted: 06/17/2016] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Binge eating is characterized by repeated intermittent bouts of compulsive overconsumption of food. Treatment is challenging given limited understanding of the mechanisms underlying this type of disordered eating. The hypothesis that dysregulation of mesocortical dopaminergic and GABAergic systems underlie binge eating was tested. METHODS Analysis of gene expression within the ventral tegmental area and its terminal mesocortical regions was examined in bingeing rats before and after bingeing occurred. In addition, alterations in binge-type behavior induced by pharmacological inactivation of subnuclei of the prefrontal cortex (PFC) and by pharmacological activation and inhibition of cortical D1 and D2 receptors were examined. RESULTS Correlative and functional evidence demonstrates dysregulated neurotransmitter processing by the PFC and ventral tegmental area, but not the amygdala or nucleus accumbens, in bingeing rats. Either GABAergic inactivation or D2-like receptor activation within the PFC increased consumption in bingeing rats, but not controls, suggesting that the PFC, and D2 receptors in particular, functions as a behavioral brake to limit bingeing. CONCLUSIONS The act of bingeing resolved some gene expression differences that preceded binge onset, further suggesting that bingeing may partially serve to self-medicate a system driving this maladaptive behavior. However, the failure of bingeing to resolve other dopaminergic/GABAergic differences may render individuals vulnerable to future binge episodes.
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Affiliation(s)
- Rebecca L W Corwin
- Nutritional Sciences Department, College of Health and Human Development, The Pennsylvania State University, University Park, Pennsylvania, USA.
| | - Francis H E Wojnicki
- Nutritional Sciences Department, College of Health and Human Development, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Derek J Zimmer
- Department of Psychiatry, Translational Neuroscience Program, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - R Keith Babbs
- Nutritional Sciences Department, College of Health and Human Development, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Lauren E McGrath
- Department of Psychiatry, Translational Neuroscience Program, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Diana R Olivos
- Department of Psychiatry, Translational Neuroscience Program, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Elizabeth G Mietlicki-Baase
- Department of Psychiatry, Translational Neuroscience Program, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Matthew R Hayes
- Department of Psychiatry, Translational Neuroscience Program, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
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High fat diet augments amphetamine sensitization in mice: Role of feeding pattern, obesity, and dopamine terminal changes. Neuropharmacology 2016; 109:170-182. [PMID: 27267686 DOI: 10.1016/j.neuropharm.2016.06.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 05/21/2016] [Accepted: 06/03/2016] [Indexed: 11/20/2022]
Abstract
High fat (HF) diet-induced obesity has been shown to augment behavioral responses to psychostimulants that target the dopamine system. The purpose of this study was to characterize dopamine terminal changes induced by a HF diet that correspond with enhanced locomotor sensitization to amphetamine. C57BL/6J mice had limited (2hr 3 d/week) or extended (24 h 7 d/week) access to a HF diet or standard chow for six weeks. Mice were then repeatedly exposed to amphetamine (AMPH), and their locomotor responses to an amphetamine challenge were measured. Fast scan cyclic voltammetry was used to identify changes in dopamine terminal function after AMPH exposure. Exposure to a HF diet reduced dopamine uptake and increased locomotor responses to acute, high-dose AMPH administration compared to chow fed mice. Microdialysis showed elevated extracellular dopamine in the nucleus accumbens (NAc) coincided with enhanced locomotion after acute AMPH in HF-fed mice. All mice exhibited locomotor sensitization to amphetamine, but both extended and limited access to a HF diet augmented this response. Neither HF-fed group showed the robust amphetamine sensitization-induced increases in dopamine release, reuptake, and amphetamine potency observed in chow fed animals. However, the potency of amphetamine as an uptake inhibitor was significantly elevated after sensitization in mice with extended (but not limited) access to HF. Conversely, after amphetamine sensitization, mice with limited (but not extended) access to HF displayed reduced autoreceptor sensitivity to the D2/D3 agonist quinpirole. Additionally, we observed reduced membrane dopamine transporter (DAT) levels after HF, and a shift in DAT localization to the cytosol was detected with limited access to HF. This study showed that different patterns of HF exposure produced distinct dopamine terminal adaptations to repeated AMPH, which differed from chow fed mice, and enhanced sensitization to AMPH. Locomotor sensitization in chow fed mice coincided with elevated DAT function and increased AMPH potency; however, the enhanced behavioral response to AMPH after HF exposure was unique in that it coincided with reduced DAT function and diet pattern-specific adaptations.
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King S, Rodrigues T, Watts A, Murray E, Wilson A, Abizaid A. Investigation of a role for ghrelin signaling in binge-like feeding in mice under limited access to high-fat diet. Neuroscience 2016; 319:233-45. [DOI: 10.1016/j.neuroscience.2016.01.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 01/04/2016] [Accepted: 01/07/2016] [Indexed: 12/25/2022]
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Wojnicki FHE, Johnson DS, Charny G, Corwin RLW. Development of bingeing in rats altered by a small operant requirement. Physiol Behav 2015; 152:112-8. [PMID: 26375821 PMCID: PMC4633377 DOI: 10.1016/j.physbeh.2015.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 08/25/2015] [Accepted: 09/09/2015] [Indexed: 12/28/2022]
Abstract
Previous studies have shown that providing an optional food for a brief period of time to non-food deprived rats on an intermittent basis in the home cage engenders significantly more intake (binge-type behavior) than when the optional food is provided for a brief period on a daily basis. Experiment 1 examined the effects of placing a small operant response requirement on access to an optional food (vegetable shortening) on the establishment of binge-type behavior. Experiment 2 examined the effects of different schedules of reinforcement, a period of abstinence from shortening, and 24h of food deprivation on established binge-type behavior. In Experiment 1 the group of rats with 30-min access to shortening on an intermittent basis in their home cages (IC) consumed significantly more shortening than the group with 30-min daily access in the home cage (DC). The group with 30-min intermittent access in an operant chamber (IO group) earned significantly more reinforcers than the group with 30-min daily access in an operant chamber (DO). In Experiment 2, the IO group earned significantly more reinforcers than the DO group regardless of the response cost, the period of shortening abstinence, and overnight food deprivation. These results demonstrate that while intermittent access generates binge-type eating, the size of the binge (intake) can be altered by different contingency arrangements.
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Affiliation(s)
- F H E Wojnicki
- Pennsylvania State University, Nutritional Sciences, 110 Chandlee Laboratory, University Park, PA 16802, United States
| | - D S Johnson
- University of Pennsylvania, School of Medicine, Department of Pathology and Laboratory Medicine, Virology, Philadelphia, PA 19104, United States
| | - G Charny
- Womack Army Medical Center, Department of Emergency Medicine, 2817 Reilly Street, Fort Bragg, NC 28310, United States
| | - R L W Corwin
- Pennsylvania State University, Nutritional Sciences, 110 Chandlee Laboratory, University Park, PA 16802, United States.
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Kirshenbaum A, Green J, Fay M, Parks A, Phillips J, Stone J, Roy T. Reinforcer devaluation as a consequence of acute nicotine exposure and withdrawal. Psychopharmacology (Berl) 2015; 232:1583-94. [PMID: 25401169 PMCID: PMC4397123 DOI: 10.1007/s00213-014-3792-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 10/24/2014] [Indexed: 12/24/2022]
Abstract
RATIONALE Nicotine discontinuation produces behaviors in rats that are congruent with anhedonia, and these symptoms may be related to the devaluation of non-nicotine reinforcers. OBJECTIVE Four separate experiments were performed to explore the parameters surrounding nicotine-induced reinforcer devaluation. METHODS In Experiments 1 and 2, nicotine (0.1 or 0.3 mg/kg) or 0.3 mg/kg nicotine plus 1.0 mg/kg mecamylamine was delivered to rats prior to progressive ratio (PR) schedule sessions in which sucrose was used as a reinforcer. In order to evaluate (a) reinforcer enhancement by nicotine and (b) reinforcer devaluation in the absence of nicotine, all rats experienced two PR schedule sessions per day for 10 days. Experiment 3 involved nicotine (0.3 mg/kg) and a visual stimulus in place of sucrose reinforcement. In Experiment 4, rats received nicotine (0.3 mg/kg) either before or after a single PR schedule session for 10 days. RESULTS Experiments 1 and 2 demonstrate that reinforcer devaluation is related to the occupation of nicotinic-acetylcholine receptors. Results from Experiment 3 provide some evidence that devaluation occurs with either sucrose or visual-stimulus reinforcement. Experiment 4 demonstrates that a necessary condition for reinforcer devaluation to occur is the concurrent exposure to the reinforcer and nicotine. CONCLUSIONS Reinforcer devaluation in rats emerges rapidly in a progressive, orderly fashion that coincides with accumulated exposure to nicotine. These results suggest that reinforcer devaluation may be a feature of nicotine that contributes to the abuse liability of tobacco products.
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Affiliation(s)
- Ari Kirshenbaum
- Department of Psychology, Saint Michael's College, 1 Winooski Park Avenue, Colchester, VT, 05439-0001, USA,
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Measurement of food reinforcement in preschool children. Associations with food intake, BMI, and reward sensitivity. Appetite 2013; 72:21-7. [PMID: 24090537 DOI: 10.1016/j.appet.2013.09.018] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 08/03/2013] [Accepted: 09/18/2013] [Indexed: 01/15/2023]
Abstract
Progressive ratio (PR) schedules of reinforcement have been used to measure the relative reinforcing value (RRV) of food in humans as young as 8 years old; however, developmentally appropriate measures are needed to measure RRV of food earlier in life. Study objectives were to demonstrate the validity of the RRV of food task adapted for use among for preschool children (3-5 y), and examine individual differences in performance. Thirty-three children completed the RRV of food task in which they worked to access graham crackers. They also completed a snack task where they had free access these foods, liking and hunger assessments, and their heights and weights were measured. Parents reported on their child's reward sensitivity. Overall, children were willing work for palatable snack foods. Boys and older children made more responses in the task, while children with higher BMI z-scores and reward sensitivity responded at a faster rate. Children who worked harder in terms of total responses and response rates consumed more calories in the snack session. This study demonstrates that with slight modifications, the RRV of food task is a valid and developmentally appropriate measure for assessing individual differences in food reinforcement among very young children.
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Wojnicki FHE, Babbs RK, Corwin RLW. Environments predicting intermittent shortening access reduce operant performance but not home cage binge size in rats. Physiol Behav 2013; 116-117:35-43. [PMID: 23535243 DOI: 10.1016/j.physbeh.2013.03.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Revised: 01/17/2013] [Accepted: 03/14/2013] [Indexed: 01/01/2023]
Abstract
When non-food-deprived rats are given brief access to vegetable shortening (a semi-solid fat used in baked products) on an intermittent basis (Monday, Wednesday, Friday), they consume significantly more and emit more operant responses for shortening than a separate group of rats given brief access to shortening every day. Since both groups are traditionally housed in the same room, it is possible that the environmental cues associated with placing shortening in the cages (e.g., investigator in room, cages opening and closing, etc.) provide predictable cues to the daily group, but unpredictable cues to the intermittent group. The present study examined the effects of providing predictable environmental cues to an isolated intermittent group in order to examine the independent contributions of intermittency and predictability on intake and operant performance. Two groups of rats were housed in the same room, with one group provided 30-min intermittent (INT) access and the second group provided 30-min daily access (D) to shortening. A third group (ISO) of rats was housed in a room by themselves in which all environmental cues associated with intermittent shortening availability were highly predictable. After five weeks of home cage shortening access, all rats were then exposed to several different operant schedules of reinforcement. The INT and ISO groups consumed significantly more shortening in the home cage than the D group. In contrast, the INT group earned significantly more reinforcers than both the ISO and D groups under all but one of the reinforcement schedules, while ISO and D did not differ. These data indicate that intermittent access will generate binge-type eating in the home cage independent of cue predictability. However, predictable cues in the home cage reduce operant responding independent of intermittent access.
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Affiliation(s)
- F H E Wojnicki
- The Pennsylvania State University, Nutritional Sciences, 110 Chandlee Laboratory, University Park, PA 16802, United States.
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Lardeux S, Kim JJ, Nicola SM. Intermittent access to sweet high-fat liquid induces increased palatability and motivation to consume in a rat model of binge consumption. Physiol Behav 2013; 114-115:21-31. [PMID: 23499930 DOI: 10.1016/j.physbeh.2013.03.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 01/16/2013] [Accepted: 03/05/2013] [Indexed: 12/16/2022]
Abstract
Binge eating disorders are characterized by discrete episodes of rapid and excessive food consumption. In rats, giving intermittent access to sweet fat food mimics this aspect of binge eating. These models typically employ solid food; however, the total amount consumed depends on motivation, palatability and satiety, which are difficult to dissociate with solid food. In contrast, lick microstructure analysis can be used to dissociate these parameters when the ingestant is a liquid. Therefore, we developed a binge model using a liquid emulsion composed of corn oil, heavy cream and sugar. We show that rats given intermittent access to this high-fat emulsion develop binge-like behavior comparable to that previously observed with solid high-fat food. One feature of this behavior was a gradual escalation in consumption across 2.5 weeks of intermittent access, which was not apparent in rats given lower-fat liquid on the same access schedule. Lick microstructure analysis suggests that this escalation was due at least in part to increases in both motivation to consume and palatability-driven consumption.
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Affiliation(s)
- Sylvie Lardeux
- Department of Psychiatry and Behavioral Science and Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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21
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Baclofen-induced reductions in optional food intake depend upon food composition. Appetite 2013; 64:62-70. [PMID: 23321345 DOI: 10.1016/j.appet.2013.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 12/28/2012] [Accepted: 01/07/2013] [Indexed: 01/09/2023]
Abstract
Baclofen reduces intake of some foods but stimulates intake or has no effect on others. The reasons for these differences are not known. The present study examined effects of baclofen when composition, energy density, preference, presentation and intake of optional foods varied. Semi-solid fat emulsions and sucrose products were presented for brief periods to non-food-deprived rats. In Experiment 1, fat and sucrose composition were varied while controlling energy density. In Experiment 2A, schedule of access and the number of optional foods were varied. In Experiment 2B, the biopolymer (thickener) was examined. Baclofen reduced intake of fat and/or sugar options with different energy densities (1.28-9kcal/g), when presented daily or intermittently, and when intakes were relatively high or low. However, the efficacy of baclofen was affected by the biopolymer used to thicken the options: baclofen had no effect when options were thickened with one biopolymer (3173), but reduced intake when options were thickened with another biopolymer (515). Baclofen failed to reduce intake of a concentrated sugar option (64% sucrose), regardless of biopolymer. Based upon these results, caution is urged when interpreting results obtained with products using different thickening agents. Systematic research is needed when designing products used in rat models of food intake.
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Corwin RLW, Wojnicki FHE. Binge-Type Eating Induced by Limited Access to Optional Foods. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/978-1-62703-104-2_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
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Babbs RK, Wojnicki FHE, Corwin RLW. Assessing binge eating. An analysis of data previously collected in bingeing rats. Appetite 2012; 59:478-82. [PMID: 22641146 DOI: 10.1016/j.appet.2012.05.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 05/11/2012] [Accepted: 05/18/2012] [Indexed: 12/28/2022]
Abstract
As interest in the study of binge eating has increased, several measures of bingeing have been developed for use in animal models. Two of the measures that have been used to distinguish binge-type from normal intake in animal studies are: (1) comparing intake at a given point in time between groups, and (2) assessing escalation of intake across time within groups. Here we use both of these measures to reanalyze data from 10 previous bingeing experiments conducted in our lab. Additionally, the data from two of these studies were then restructured in order to evaluate the use of these measures in binge eating prone (BEP) and resistant (BER) rats, as described by others. Analyses comparing intake at a given point in time indicated bingeing in all 10 studies, while comparisons of escalation indicated bingeing in 9 out of 10 studies. The goal of this study was to compare and contrast the two measures, identify the strengths and weaknesses of each, and determine their appropriateness for a given set of potential outcomes. The results indicate that both intake and escalation are useful measures. However, their limitations need to be taken into consideration when attempting to operationalize binge-type eating in animal models.
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Affiliation(s)
- R K Babbs
- 110 Chandlee Laboratory, IGDP Physiology, Pennsylvania State University, University Park, PA 16802, USA.
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Pandit R, Mercer JG, Overduin J, la Fleur SE, Adan RAH. Dietary factors affect food reward and motivation to eat. Obes Facts 2012; 5:221-42. [PMID: 22647304 DOI: 10.1159/000338073] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 10/25/2011] [Indexed: 01/09/2023] Open
Abstract
The propensity to indulge in unhealthy eating and overconsumption of palatable food is a crucial determinant in the rising prevalence of obesity in today's society. The tendency to consume palatable foods in quantities that exceed energy requirements has been linked to an addiction-like process. Although the existence of 'food addiction' has not been conclusively proven, evidence points to alterations in the brain reward circuitry induced by overconsumption of palatable foods that are similar to those seen in drug addiction. The diet-induced obesity paradigm is a common procedure to replicate features of human obesity in rodents. Here we review data on the effect of various obesogenic diets (high-fat, Ensure™, cafeteria type, sucrose) on the extent of leptin resistance, hypothalamic-neuropeptidergic adaptations and changes in feeding behavior. We also discuss to what extent such diets and properties such as macronutrient composition, physical structure, sensory stimuli, and post-ingestive effects influence the brain-reward pathways. Understanding the interaction between individual components of diets, feeding patterns, and brain reward pathways could facilitate the design of diets that limit overconsumption and prevent weight gain.
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Affiliation(s)
- Rahul Pandit
- Rudolf Magnus Institute of Neuroscience, Department of Neuroscience and Pharmacology, University Medical Center Utrecht, Utrecht, the Netherlands
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Puhl MD, Cason AM, Wojnicki FHE, Corwin RL, Grigson PS. A history of bingeing on fat enhances cocaine seeking and taking. Behav Neurosci 2011; 125:930-42. [PMID: 21988520 PMCID: PMC3226865 DOI: 10.1037/a0025759] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Binge eating and substance dependence are disorders characterized by a loss of control over consummatory behaviors. Given the common characteristics of these two types of disorders, it is not surprising that the comorbidity between eating disorders and substance abuse disorders is high (20-40%; Conason et al., 2006). It is unknown, however, whether loss of control in one disorder predisposes an individual to loss of control in the other. The present study, therefore, used a rodent model to test whether a history of binge eating would augment subsequent responding for cocaine. Using the limited access protocol described by Corwin et al. (1998), 45 adult male Sprague-Dawley rats were maintained on one of four dietary protocols for a period of six weeks: chow only (Chow; n = 9), continuous access to an optional source of dietary fat (Ad Lib; n = 12), 1-h access to an optional source of dietary fat daily (Daily; n = 12), or 1-h access to an optional source of dietary fat on Monday, Wednesday, and Friday (MWF; n = 12). All four groups also had unrestricted access to a nutritionally complete diet of chow and water. Fat-bingeing behaviors developed in the MWF rats, the group with the most restricted access to the optional fat. Thereafter, cocaine-seeking and -taking behaviors were assessed in all rats using a self-administration protocol modified from that described by Deroche-Gamonet et al. (2004), which focused on the motivation for and preoccupation with obtaining and consuming drug (assessed using a progressive ratio [PR] schedule of reinforcement) and persistence in responding for drug during periods of signaled drug non-availability (SNA). Rats with the MWF history tended to take more cocaine late in fixed ratio (FR) training, they persisted in their efforts to obtain cocaine in the face of signaled non-availability, worked harder for cocaine on a PR schedule of reinforcement, and exhibited more goal-directed behavior toward the cocaine-associated operandum. These results demonstrate a link between binge-type intake of fat and the development of drug-seeking and -taking behaviors, suggesting that a history of fat bingeing may predispose individuals to exhibit more robust "addiction-like" behaviors toward a substance of abuse. Thus, it appears that conditions promoting excessive behavior toward one substance (e.g., a palatable fatty food) beget excessive behavior toward another (e.g., cocaine).
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Affiliation(s)
- Matthew D. Puhl
- Department of Neural and Behavioral Sciences, The Pennsylvania State University College of Medicine
| | - Angie M. Cason
- Department of Neural and Behavioral Sciences, The Pennsylvania State University College of Medicine
| | | | - Rebecca L. Corwin
- Department of Nutritional Sciences, The Pennsylvania State University
| | - Patricia S. Grigson
- Department of Neural and Behavioral Sciences, The Pennsylvania State University College of Medicine
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Egecioglu E, Skibicka KP, Hansson C, Alvarez-Crespo M, Friberg PA, Jerlhag E, Engel JA, Dickson SL. Hedonic and incentive signals for body weight control. Rev Endocr Metab Disord 2011; 12:141-51. [PMID: 21340584 PMCID: PMC3145094 DOI: 10.1007/s11154-011-9166-4] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Here we review the emerging neurobiological understanding of the role of the brain's reward system in the regulation of body weight in health and in disease. Common obesity is characterized by the over-consumption of palatable/rewarding foods, reflecting an imbalance in the relative importance of hedonic versus homeostatic signals. The popular 'incentive salience theory' of food reward recognises not only a hedonic/pleasure component ('liking') but also an incentive motivation component ('wanting' or 'reward-seeking'). Central to the neurobiology of the reward mechanism is the mesoaccumbal dopamine system that confers incentive motivation not only for natural rewards such as food but also by artificial rewards (eg. addictive drugs). Indeed, this mesoaccumbal dopamine system receives and integrates information about the incentive (rewarding) value of foods with information about metabolic status. Problematic over-eating likely reflects a changing balance in the control exerted by hypothalamic versus reward circuits and/or it could reflect an allostatic shift in the hedonic set point for food reward. Certainly, for obesity to prevail, metabolic satiety signals such as leptin and insulin fail to regain control of appetitive brain networks, including those involved in food reward. On the other hand, metabolic control could reflect increased signalling by the stomach-derived orexigenic hormone, ghrelin. We have shown that ghrelin activates the mesoaccumbal dopamine system and that central ghrelin signalling is required for reward from both chemical drugs (eg alcohol) and also from palatable food. Future therapies for problematic over-eating and obesity may include drugs that interfere with incentive motivation, such as ghrelin antagonists.
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Affiliation(s)
- Emil Egecioglu
- Department of Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 11, PO Box 434, SE-405 30 Gothenburg, Sweden
| | - Karolina P. Skibicka
- Department of Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 11, PO Box 434, SE-405 30 Gothenburg, Sweden
| | - Caroline Hansson
- Department of Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 11, PO Box 434, SE-405 30 Gothenburg, Sweden
| | - Mayte Alvarez-Crespo
- Department of Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 11, PO Box 434, SE-405 30 Gothenburg, Sweden
| | - P. Anders Friberg
- Department of Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 11, PO Box 434, SE-405 30 Gothenburg, Sweden
| | - Elisabet Jerlhag
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 11, PO Box 434, SE-405 30 Gothenburg, Sweden
| | - Jörgen A. Engel
- Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 11, PO Box 434, SE-405 30 Gothenburg, Sweden
| | - Suzanne L. Dickson
- Department of Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 11, PO Box 434, SE-405 30 Gothenburg, Sweden
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Corwin RL, Avena NM, Boggiano MM. Feeding and reward: perspectives from three rat models of binge eating. Physiol Behav 2011; 104:87-97. [PMID: 21549136 PMCID: PMC3132131 DOI: 10.1016/j.physbeh.2011.04.041] [Citation(s) in RCA: 213] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 04/23/2011] [Accepted: 04/26/2011] [Indexed: 12/24/2022]
Abstract
Research has focused on understanding how overeating can affect brain reward mechanisms and subsequent behaviors, both preclinically and in clinical research settings. This work is partly driven by the need to uncover the etiology and possible treatments for the ongoing obesity epidemic. However, overeating, or non-homeostatic feeding behavior, can occur independent of obesity. Isolating the variable of overeating from the consequence of increased body weight is of great utility, as it is well known that increased body weight or obesity can impart its own deleterious effects on physiology, neural processes, and behavior. In this review, we present data from three selected animal models of normal-weight non-homeostatic feeding behavior that have been significantly influenced by Bart Hoebel's 40+-yr career studying motivation, feeding, reinforcement, and the neural mechanisms that participate in the regulation of these processes. First, a model of sugar bingeing is described (Avena/Hoebel), in which animals with repeated, intermittent access to a sugar solution develop behaviors and brain changes that are similar to the effects of some drugs of abuse, serving as the first animal model of food addiction. Second, another model is described (Boggiano) in which a history of dieting and stress can perpetuate further binge eating of palatable and non-palatable food. In addition, a model (Boggiano) is described that allows animals to be classified as having a binge-prone vs. binge-resistant behavioral profile. Lastly, a limited access model is described (Corwin) in which non-food deprived rats with sporadic limited access to a high-fat food develop binge-type behaviors. These models are considered within the context of their effects on brain reward systems, including dopamine, the opioids, cholinergic systems, serotonin, and GABA. Collectively, the data derived from the use of these models clearly show that behavioral and neuronal consequences of bingeing on a palatable food, even when at a normal body weight, are different from those that result from simply consuming the palatable food in a non-binge manner. These findings may be important in understanding how overeating can influence behavior and brain chemistry.
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Affiliation(s)
- Rebecca L Corwin
- Nutritional Sciences Dept., College of Health and Human Development, The Pennsylvania State University, University Park, PA 16802, United States.
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Epstein LH, Carr KA, Lin H, Fletcher KD. Food reinforcement, energy intake, and macronutrient choice. Am J Clin Nutr 2011; 94:12-8. [PMID: 21543545 PMCID: PMC3127525 DOI: 10.3945/ajcn.110.010314] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Food is a powerful reinforcer that motivates people to eat. The relative reinforcing value of food (RRV(food)) is associated with obesity and energy intake and interacts with impulsivity to predict energy intake. OBJECTIVE How RRV(food) is related to macronutrient choice in ad libitum eating tasks in humans has not been studied; however, animal research suggests that sugar or simple carbohydrates may be a determinant of reward value in food. This study assessed which macronutrients are associated with food reinforcement. DESIGN Two hundred seventy-three adults with various body mass indexes were assessed for RRV(food), the relative reinforcing value of reading, food hedonics, energy intake in an ad libitum taste test, and usual energy intake derived from repeated 24-h dietary recalls. Multiple regression was used to assess the relation between predictors of total energy and energy associated with macronutrient intake after control for age, sex, income, education, minority status, and other macronutrient intakes. RESULTS The results showed that the relative proportion of responding for food compared with reading (RRV(prop)) was positively related to body mass index, laboratory-measured energy intake, and usual energy intake. In addition, RRV(prop) was a predictor of sugar intake but not of total carbohydrate, fat, or protein intake. CONCLUSION These results are consistent with basic animal research showing that sugar is related to food reward and with the hypothesis that food reward processes are more strongly related to eating than are food hedonics. This trial was registered at clinicaltrials.gov as NCT00962117.
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Affiliation(s)
- Leonard H Epstein
- Department of Pediatrics, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, NY 14214-3000, USA.
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