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Li AQ, Li SS, Zhang RX, Zhao XY, Liu ZY, Hu Y, Wang B, Neely GG, Simpson SJ, Wang QP. Nutritional geometry framework of sucrose taste in Drosophila. J Genet Genomics 2023; 50:233-240. [PMID: 36773723 DOI: 10.1016/j.jgg.2023.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/27/2023] [Accepted: 02/01/2023] [Indexed: 02/11/2023]
Abstract
Dietary protein (P) and carbohydrate (C) have a major impact on sweet taste sensation. However, it remains unclear whether the balance of P and C influences sweet taste sensitivity. Here, we use the nutritional geometry framework (NGF) to address the interaction of protein and carbohydrates and on sweet taste using Drosophila as a model. Our results reveal that high-protein, low-carbohydrate (HPLC) diets sensitize to sweet taste and low-protein, high-carbohydrate (LPHC) diets desensitize sweet taste in both male and female flies. We further investigate the underlying mechanisms of these two diets' effect on sweet taste using RNA sequencing. When compared to the LPHC diet, the mRNA expression of genes involved in the metabolism of glycine, serine, and threonine is significantly upregulated in the HPLC diet, suggesting these amino acids may mediate sweet taste perception. We further find that sweet sensitization occurs in flies fed with the LPHC diet supplemented with serine and threonine. Our study demonstrates that sucrose taste sensitivity is affected by the balance of dietary protein and carbohydrates possibly through changes in serine and threonine.
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Affiliation(s)
- An-Qi Li
- Laboratory of Metabolism and Aging, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Sha-Sha Li
- Laboratory of Metabolism and Aging, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Ruo-Xin Zhang
- Laboratory of Metabolism and Aging, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Xin-Yuan Zhao
- Laboratory of Metabolism and Aging, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Zhi-Ying Liu
- Laboratory of Metabolism and Aging, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Yun Hu
- Laboratory of Metabolism and Aging, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - Bei Wang
- Laboratory of Metabolism and Aging, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, Guangdong 518107, China
| | - G Gregory Neely
- The Dr. John and Anne Chong Laboratory for Functional Genomics, Charles Perkins Centre and School of Life & Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Stephen J Simpson
- Charles Perkins Centre and School of Life & Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Qiao-Ping Wang
- Laboratory of Metabolism and Aging, School of Pharmaceutical Sciences (Shenzhen), Shenzhen Campus of Sun Yat-sen University, Shenzhen, Guangdong 518107, China.
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Uddin O, Anderson M, Smith J, Masri R, Keller A. Parabrachial complex processes dura inputs through a direct trigeminal ganglion-to-parabrachial connection. NEUROBIOLOGY OF PAIN 2021; 9:100060. [PMID: 33537510 PMCID: PMC7840999 DOI: 10.1016/j.ynpai.2021.100060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/18/2020] [Accepted: 01/17/2021] [Indexed: 11/11/2022]
Abstract
Parabrachial complex (PB) neurons respond reliably to dura stimulation. Trigeminal ganglion (TG) neurons project directly to PB. TG neurons project to both dura and PB, demonstrating a direct connection.
Migraines cause significant disability and contribute heavily to healthcare costs. Irritation of the meninges’ outermost layer (the dura mater), and trigeminal ganglion activation contribute to migraine initiation. Maladaptive changes in central pain-processing regions are also important in maintaining pain. The parabrachial complex (PB) is a central region that mediates chronic pain. PB receives diverse sensory information, including a direct input from the trigeminal ganglion. We hypothesized that PB processes inputs from the dura. Using in vivo electrophysiology recordings from single units in anesthetized rats we identified 58 neurons in lateral PB that respond reliably and with short latency to electrical dura stimulation. After injecting tracer into PB, anatomical examination reveals retrogradely labeled cell bodies in the trigeminal ganglion. Neuroanatomical tract-tracing revealed a population of neurons in the trigeminal ganglion that innervate the dura and project directly to PB. These findings indicate that PB is strategically placed to process dura inputs and suggest that it is directly involved in the pathogenesis of migraine headaches.
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Affiliation(s)
- Olivia Uddin
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Michael Anderson
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Jesse Smith
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Radi Masri
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, United States
| | - Asaf Keller
- Department of Anatomy and Neurobiology, Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, United States
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Bake T, Le May MV, Edvardsson CE, Vogel H, Bergström U, Albers MN, Skibicka KP, Farkas I, Liposits Z, Dickson SL. Ghrelin Receptor Stimulation of the Lateral Parabrachial Nucleus in Rats Increases Food Intake but not Food Motivation. Obesity (Silver Spring) 2020; 28:1503-1511. [PMID: 32627950 DOI: 10.1002/oby.22875] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/25/2020] [Accepted: 04/25/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVE The lateral parabrachial nucleus (lPBN) in the brainstem has emerged as a key area involved in feeding control that is targeted by several circulating anorexigenic hormones. Here, the objective was to determine whether the lPBN is also a relevant site for the orexigenic hormone ghrelin, inspired by studies in mice and rats showing that there is an abundance of ghrelin receptors in this area. METHODS This study first explored whether iPBN cells respond to ghrelin involving Fos mapping and electrophysiological studies in rats. Next, rats were injected acutely with ghrelin, a ghrelin receptor antagonist, or vehicle into the lPBN to investigate feeding-linked behaviors. RESULTS Curiously, ghrelin injection (intracerebroventricular or intravenous) increased Fos protein expression in the lPBN yet the predominant electrophysiological response was inhibitory. Intra-lPBN ghrelin injection increased chow or high-fat diet intake, whereas the antagonist decreased chow intake only. In a choice paradigm, intra-lPBN ghrelin increased intake of chow but not lard or sucrose. Intra-lPBN ghrelin did not alter progressive ratio lever pressing for sucrose or conditioned place preference for chocolate. CONCLUSIONS The lPBN is a novel locus from which ghrelin can alter consummatory behaviors (food intake and choice) but not appetitive behaviors (food reward and motivation).
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Affiliation(s)
- Tina Bake
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Marie V Le May
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Christian E Edvardsson
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Heike Vogel
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Ulrika Bergström
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Marjorie Nicholson Albers
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
| | - Karolina P Skibicka
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
- Department of Nutritional Sciences, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Imre Farkas
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Zsolt Liposits
- Department of Endocrine Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Suzanne L Dickson
- Department of Physiology/Endocrine, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
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Raver C, Uddin O, Ji Y, Li Y, Cramer N, Jenne C, Morales M, Masri R, Keller A. An Amygdalo-Parabrachial Pathway Regulates Pain Perception and Chronic Pain. J Neurosci 2020; 40:3424-3442. [PMID: 32217613 PMCID: PMC7178908 DOI: 10.1523/jneurosci.0075-20.2020] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 03/09/2020] [Accepted: 03/11/2020] [Indexed: 02/07/2023] Open
Abstract
The parabrachial (PB) complex mediates both ascending nociceptive signaling and descending pain modulatory information in the affective/emotional pain pathway. We have recently reported that chronic pain is associated with amplified activity of PB neurons in a rat model of neuropathic pain. Here we demonstrate that similar activity amplification occurs in mice, and that this is related to suppressed inhibition to lateral parabrachial (LPB) neurons from the CeA in animals of either sex. Animals with pain after chronic constriction injury of the infraorbital nerve (CCI-Pain) displayed higher spontaneous and evoked activity in PB neurons, and a dramatic increase in after-discharges, responses that far outlast the stimulus, compared with controls. LPB neurons in CCI-Pain animals showed a reduction in inhibitory, GABAergic inputs. We show that, in both rats and mice, LPB contains few GABAergic neurons, and that most of its GABAergic inputs arise from CeA. These CeA GABA neurons express dynorphin, somatostatin, and/or corticotropin releasing hormone. We find that the efficacy of this CeA-LPB pathway is suppressed in chronic pain. Further, optogenetically stimulating this pathway suppresses acute pain, and inhibiting it, in naive animals, evokes pain behaviors. These findings demonstrate that the CeA-LPB pathway is critically involved in pain regulation, and in the pathogenesis of chronic pain.SIGNIFICANCE STATEMENT We describe a novel pathway, consisting of inhibition by dynorphin, somatostatin, and corticotropin-releasing hormone-expressing neurons in the CeA that project to the parabrachial nucleus. We show that this pathway regulates the activity of pain-related neurons in parabrachial nucleus, and that, in chronic pain, this inhibitory pathway is suppressed, and that this suppression is causally related to pain perception. We propose that this amygdalo-parabrachial pathway is a key regulator of both chronic and acute pain, and a novel target for pain relief.
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Affiliation(s)
- Charles Raver
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Olivia Uddin
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Yadong Ji
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland 21201
| | - Ying Li
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Nathan Cramer
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Carleigh Jenne
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Marisela Morales
- Neuronal Networks Section, Intramural Research Program, National Institute on Drug Abuse, Baltimore, Maryland 21224
| | - Radi Masri
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, Maryland 21201
| | - Asaf Keller
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201
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5
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Ferrucci M, Limanaqi F, Ryskalin L, Biagioni F, Busceti CL, Fornai F. The Effects of Amphetamine and Methamphetamine on the Release of Norepinephrine, Dopamine and Acetylcholine From the Brainstem Reticular Formation. Front Neuroanat 2019; 13:48. [PMID: 31133823 PMCID: PMC6524618 DOI: 10.3389/fnana.2019.00048] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/26/2019] [Indexed: 12/22/2022] Open
Abstract
Amphetamine (AMPH) and methamphetamine (METH) are widely abused psychostimulants, which produce a variety of psychomotor, autonomic and neurotoxic effects. The behavioral and neurotoxic effects of both compounds (from now on defined as AMPHs) stem from a fair molecular and anatomical specificity for catecholamine-containing neurons, which are placed in the brainstem reticular formation (RF). In fact, the structural cross-affinity joined with the presence of shared molecular targets between AMPHs and catecholamine provides the basis for a quite selective recruitment of brainstem catecholamine neurons following AMPHs administration. A great amount of investigations, commentary manuscripts and books reported a pivotal role of mesencephalic dopamine (DA)-containing neurons in producing behavioral and neurotoxic effects of AMPHs. Instead, the present review article focuses on catecholamine reticular neurons of the low brainstem. In fact, these nuclei add on DA mesencephalic cells to mediate the effects of AMPHs. Among these, we also include two pontine cholinergic nuclei. Finally, we discuss the conundrum of a mixed neuronal population, which extends from the pons to the periaqueductal gray (PAG). In this way, a number of reticular nuclei beyond classic DA mesencephalic cells are considered to extend the scenario underlying the neurobiology of AMPHs abuse. The mechanistic approach followed here to describe the action of AMPHs within the RF is rooted on the fine anatomy of this region of the brainstem. This is exemplified by a few medullary catecholamine neurons, which play a pivotal role compared with the bulk of peripheral sympathetic neurons in sustaining most of the cardiovascular effects induced by AMPHs.
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Affiliation(s)
- Michela Ferrucci
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Fiona Limanaqi
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Larisa Ryskalin
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | | | | | - Francesco Fornai
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- IRCCS Neuromed, Pozzilli, Italy
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6
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Uddin O, Studlack P, Akintola T, Raver C, Castro A, Masri R, Keller A. Amplified parabrachial nucleus activity in a rat model of trigeminal neuropathic pain. NEUROBIOLOGY OF PAIN 2018; 3:22-30. [PMID: 29862375 PMCID: PMC5973803 DOI: 10.1016/j.ynpai.2018.02.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The parabrachial (PB) complex mediates both ascending nociceptive signaling and descending pain modulatory information in the affective/emotional pain pathway. We hypothesized that PB hyperactivity influences chronic pain behavior after trigeminal nerve injury in rats. Following induction of neuropathic pain using the chronic constriction injury of the infraorbital nerve (CCI-ION) model, rats displayed spontaneous markers of pain and mechanical hyperalgesia extending beyond the receptive field of the injured nerve. PB neurons recorded from rats with CCI-ION displayed amplified activity, manifesting as significantly longer responses to sensory stimuli, compared to shams. These findings suggest that chronic neuropathic pain involves PB hyperactivity.
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Affiliation(s)
- Olivia Uddin
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD 21201, United States.,Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD 21201, United States
| | - Paige Studlack
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD 21201, United States.,Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD 21201, United States
| | - Titilola Akintola
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD 21201, United States
| | - Charles Raver
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD 21201, United States
| | - Alberto Castro
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD 21201, United States.,Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD 21201, United States
| | - Radi Masri
- Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD 21201, United States.,Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, 650 W. Baltimore St, Baltimore, MD 21201, United States
| | - Asaf Keller
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD 21201, United States.,Program in Neuroscience, University of Maryland School of Medicine, 20 Penn St, HSF-II S251, Baltimore, MD 21201, United States
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Caron A, Richard D. Neuronal systems and circuits involved in the control of food intake and adaptive thermogenesis. Ann N Y Acad Sci 2016; 1391:35-53. [PMID: 27768821 DOI: 10.1111/nyas.13263] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 08/18/2016] [Accepted: 08/24/2016] [Indexed: 12/27/2022]
Abstract
With the still-growing prevalence of obesity worldwide, major efforts are made to understand the various behavioral, environmental, and genetic factors that promote excess fat gain. Obesity results from an imbalance between energy intake and energy expenditure, which emphasizes the importance of deciphering the mechanisms behind energy balance regulation to understand its physiopathology. The control of energy balance is assured by brain systems/circuits capable of generating adequate ingestive and thermogenic responses to maintain the stability of energy reserves, which implies a proper integration of the homeostatic signals that inform about the status of the energy stores. In this article, we overview the organization and functionality of key neuronal circuits or pathways involved in the control of food intake and energy expenditure. We review the role of the corticolimbic (executive and reward) and autonomic systems that integrate their activities to regulate energy balance. We also describe the mechanisms and pathways whereby homeostatic sensing is achieved in response to variations of homeostatic hormones, such as leptin, insulin, and ghrelin, while putting some emphasis on the prominent importance of the mechanistic target of the rapamycin signaling pathway in coordinating the homeostatic sensing process.
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Affiliation(s)
- Alexandre Caron
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec and Faculty of Medicine, Department of Medicine, Université Laval, Quebec City, Quebec, Canada
| | - Denis Richard
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec and Faculty of Medicine, Department of Medicine, Université Laval, Quebec City, Quebec, Canada
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8
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Laureano DP, Dalle Molle R, Alves MB, Luft C, Desai M, Ross MG, Silveira PP. Intrauterine growth restriction modifies the hedonic response to sweet taste in newborn pups - Role of the accumbal μ-opioid receptors. Neuroscience 2016; 322:500-8. [PMID: 26926962 DOI: 10.1016/j.neuroscience.2016.02.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 02/12/2016] [Accepted: 02/16/2016] [Indexed: 12/18/2022]
Abstract
Intrauterine growth restriction (IUGR) is associated with increased preference for palatable foods. The hedonic response to sweet taste, modulated by the nucleus accumbens μ-opioid-receptors, may be involved. We investigated hedonic responses and receptor levels in IUGR and Control animals. From pregnancy day 10, Sprague-Dawley dams received either an ad libitum (Control), or a 50% food restricted (FR) diet. At birth, pups were cross-fostered, and nursed by Adlib fed dams. The hedonic response was evaluated at 1 day after birth and at 90 days of life, by giving sucrose solution or water and analyzing the hedonic facial responses (within 60s). Control pups exposed either to water or sucrose resolved their hedonic responses after 16 and 18s, respectively, while FR hedonic responses to sucrose persisted over 20s. FR pups had deceased phospho-μ-opioid-receptor (p=0.009) and reduced phosphor:total mu opioid receptor ratio compared to controls pups (p=0.003). In adults, there was an interaction between group and solution at the end of the evaluation (p=0.044): Control decreased the response after sucrose solution, FR did not change over time. There were no differences in phosphorylation of μ-opioid-receptor in adults. These results demonstrate IUGR newborn rats exhibit alterations in hedonic response accompanied by a decrease in μ-opioid-receptor phosphorylation, though these alterations do not persist at 3 months of age. Opioid system alterations in early life may contribute to the development of preference for highly palatable foods and contribute to rapid weight gain and obesity in IUGR offspring.
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Affiliation(s)
| | | | - M B Alves
- PPG Neurociências UFRGS, Porto Alegre, Brazil
| | - C Luft
- Pontífica Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - M Desai
- Dept of Ob/Gyn, Harbor-UCLA Med Ctr, Torrance, CA, United States
| | - M G Ross
- Dept of Ob/Gyn, Harbor-UCLA Med Ctr, Torrance, CA, United States
| | - P P Silveira
- PPG Neurociências UFRGS, Porto Alegre, Brazil; PPGSCA-HCPA-FAMED UFRGS, Porto Alegre, Brazil
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9
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Cross-modal interactions for custard desserts differ in obese and normal weight Italian women. Appetite 2016; 100:203-9. [PMID: 26911260 DOI: 10.1016/j.appet.2016.02.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 01/18/2016] [Accepted: 02/16/2016] [Indexed: 02/02/2023]
Abstract
The effects of variation in odors and thickening agents on sensory properties and acceptability of a model custard dessert were investigated in normal weight and obese women. Subjects rated their liking and the intensity of sensory properties (sweetness, vanilla and butter flavors, and creaminess) of 3 block samples (the first varied in vanilla aroma, the second varied in butter aroma and the third varied in xanthan gum). Significant differences were found in acceptability and intensity ratings in relation to body mass index. The addition of butter aroma in the custard was the most effective way to elicit odor-taste, odor-flavor and odor-texture interactions in obese women. In this group, butter aroma, signaling energy dense products, increased the perception of sweetness, vanilla flavor and creaminess, which are all desirable properties in a custard, while maintaining a high liking degree. Understanding cross-modal interactions in relation to nutritional status is interesting in order to develop new food products with reduced sugar and fat, that are still satisfying for the consumer. This could have important implications to reduce caloric intake and tackle the obesity epidemic.
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10
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Elson AE, Simerly RB. Developmental specification of metabolic circuitry. Front Neuroendocrinol 2015; 39:38-51. [PMID: 26407637 PMCID: PMC4681622 DOI: 10.1016/j.yfrne.2015.09.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 09/18/2015] [Accepted: 09/21/2015] [Indexed: 01/16/2023]
Abstract
The hypothalamus contains a core circuitry that communicates with the brainstem and spinal cord to regulate energy balance. Because metabolic phenotype is influenced by environmental variables during perinatal development, it is important to understand how these neural pathways form in order to identify key signaling pathways that are responsible for metabolic programming. Recent progress in defining gene expression events that direct early patterning and cellular specification of the hypothalamus, as well as advances in our understanding of hormonal control of central neuroendocrine pathways, suggest several key regulatory nodes that may represent targets for metabolic programming of brain structure and function. This review focuses on components of central circuitry known to regulate various aspects of energy balance and summarizes what is known about their developmental neurobiology within the context of metabolic programming.
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Affiliation(s)
- Amanda E Elson
- The Saban Research Institute, Children's Hospital Los Angeles, University of Southern California, Keck School of Medicine, Los Angeles, CA 90027, USA
| | - Richard B Simerly
- The Saban Research Institute, Children's Hospital Los Angeles, University of Southern California, Keck School of Medicine, Los Angeles, CA 90027, USA.
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11
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Abstract
Obesity ensues from an imbalance between energy intake and expenditure that results from gene-environment interactions, which favour a positive energy balance. A society that promotes unhealthy food and encourages sedentary lifestyle (that is, an obesogenic environment) has become a major contributory factor in excess fat deposition in individuals predisposed to obesity. Energy homeostasis relies upon control of energy intake as well as expenditure, which is in part determined by the themogenesis of brown adipose tissue and mediated by the sympathetic nervous system. Several areas of the brain that constitute cognitive and autonomic brain systems, which in turn form networks involved in the control of appetite and thermogenesis, also contribute to energy homeostasis. These networks include the dopamine mesolimbic circuit, as well as the opioid, endocannabinoid and melanocortin systems. The activity of these networks is modulated by peripheral factors such as hormones derived from adipose tissue and the gut, which access the brain via the circulation and neuronal signalling pathways to inform the central nervous system about energy balance and nutritional status. In this Review, I focus on the determinants of energy homeostasis that have emerged as prominent factors relevant to obesity.
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Affiliation(s)
- Denis Richard
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, 2725 Chemin Sainte-Foy, Québec, QC G1V 4G5, Canada
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12
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Neurotensin: revealing a novel neuromodulator circuit in the nucleus accumbens–parabrachial nucleus projection of the domestic chick. Brain Struct Funct 2014; 221:605-16. [DOI: 10.1007/s00429-014-0928-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 10/18/2014] [Indexed: 11/30/2022]
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13
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Browning KN, Hajnal A. The effects of bariatric surgery: will understanding its mechanism render the knife unnecessary? Expert Rev Gastroenterol Hepatol 2014; 8:1-4. [PMID: 24410467 PMCID: PMC4085570 DOI: 10.1586/17474124.2014.846214] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The incidence of obesity is increasing worldwide at a dramatic rate, accompanied by an associated increase in comorbid conditions. Bariatric surgery is the most effective treatment for morbid obesity with Roux-en-Y gastric bypass being the most commonly performed procedure, yet the underlying mechanisms by which it induces a wide-array of beneficial effects remains obscure. From basic science as well as clinical standpoints, there are several areas of current interest that warrant continued investigation. Several major focus areas have also emerged in current research that may guide future efforts in this field, particularly with regards to using novel, non-surgical approaches to mimic the success of bariatric surgery while minimizing its adverse side effects.
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Affiliation(s)
- Kirsteen N Browning
- Department of Neural and Behavioral Sciences, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA +1 717 531 8267
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Alsiö J, Rask-Andersen M, Chavan RA, Olszewski PK, Levine AS, Fredriksson R, Schiöth HB. Exposure to a high-fat high-sugar diet causes strong up-regulation of proopiomelanocortin and differentially affects dopamine D1 and D2 receptor gene expression in the brainstem of rats. Neurosci Lett 2014; 559:18-23. [DOI: 10.1016/j.neulet.2013.11.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 11/01/2013] [Accepted: 11/11/2013] [Indexed: 11/28/2022]
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15
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Feelings about food: the ventral tegmental area in food reward and emotional eating. Trends Pharmacol Sci 2013; 35:31-40. [PMID: 24332673 DOI: 10.1016/j.tips.2013.11.003] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 11/04/2013] [Accepted: 11/14/2013] [Indexed: 01/27/2023]
Abstract
Overconsumption of high caloric food plays an important role in the etiology of obesity. Several factors drive such hedonic feeding. High caloric food is often palatable. In addition, when an individual is sated, stress and food-related cues can serve as potent feeding triggers. A better understanding of the neurobiological underpinnings of food palatability and environmentally triggered overconsumption would aid the development of new treatment strategies. In the current review we address the pivotal role of the mesolimbic dopamine reward system in the drive towards high caloric palatable food and its relation to stress- and cue-induced feeding. We also discuss how this system may be affected by both established and potential anti-obesity drug targets.
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Cai H, Daimon CM, Cong WN, Wang R, Chirdon P, de Cabo R, Sévigny J, Maudsley S, Martin B. Longitudinal analysis of calorie restriction on rat taste bud morphology and expression of sweet taste modulators. J Gerontol A Biol Sci Med Sci 2013; 69:532-44. [PMID: 24077597 DOI: 10.1093/gerona/glt129] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Calorie restriction (CR) is a lifestyle intervention employed to reduce body weight and improve metabolic functions primarily via reduction of ingested carbohydrates and fats. Taste perception is highly related to functional metabolic status and body adiposity. We have previously shown that sweet taste perception diminishes with age; however, relatively little is known about the effects of various lengths of CR upon taste cell morphology and function. We investigated the effects of CR on taste bud morphology and expression of sweet taste-related modulators in 5-, 17-, and 30-month-old rats. In ad libitum (AL) and CR rats, we consistently found the following parameters altered significantly with advancing age: reduction of taste bud size and taste cell numbers per taste bud and reduced expression of sonic hedgehog, type 1 taste receptor 3 (T1r3), α-gustducin, and glucagon-like peptide-1 (GLP-1). In the oldest rats, CR affected a significant reduction of tongue T1r3, GLP-1, and α-gustducin expression compared with age-matched AL rats. Leptin receptor immunopositive cells were elevated in 17- and 30-month-old CR rats compared with age-matched AL rats. These alterations of sweet taste-related modulators, specifically during advanced aging, suggest that sweet taste perception may be altered in response to different lengths of CR.
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Affiliation(s)
- Huan Cai
- *These authors contributed equally to this work
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17
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Li J, Chen K, Yan J, Wang Q, Zhao X, Yang X, Yang D, Zhao S, Zhu G, Sun B. Increased sucrose intake and corresponding c-Fos in amygdala and parabrachial nucleus of dietary obese rats. Neurosci Lett 2012; 525:111-6. [DOI: 10.1016/j.neulet.2012.07.053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 07/23/2012] [Accepted: 07/24/2012] [Indexed: 12/15/2022]
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Frank ME, Goyert HF, Formaker BK, Hettinger TP. Effects of selective adaptation on coding sugar and salt tastes in mixtures. Chem Senses 2012; 37:701-9. [PMID: 22562765 DOI: 10.1093/chemse/bjs051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Little is known about coding of taste mixtures in complex dynamic stimulus environments. A protocol developed for odor stimuli was used to test whether rapid selective adaptation extracted sugar and salt component tastes from mixtures as it did component odors. Seventeen human subjects identified taste components of "salt + sugar" mixtures. In 4 sessions, 16 adapt-test stimulus pairs were presented as atomized, 150-μL "taste puffs" to the tongue tip to simulate odor sniffs. Stimuli were NaCl, sucrose, "NaCl + sucrose," and water. The sugar was 98% identified but the suppressed salt 65% identified in unadapted mixtures of 2 concentrations of NaCl, 0.1 or 0.05 M, and sucrose at 3 times those concentrations, 0.3 or 0.15 M. Rapid selective adaptation decreased identification of sugar and salt preadapted ambient components to 35%, well below the 74% self-adapted level, despite variation in stimulus concentration and adapting time (<5 or >10 s). The 96% identification of sugar and salt extra mixture components was as certain as identification of single compounds. The results revealed that salt-sugar mixture suppression, dependent on relative mixture-component concentration, was mutual. Furthermore, like odors, stronger and recent tastes are emphasized in dynamic experimental conditions replicating natural situations.
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Affiliation(s)
- Marion E Frank
- Department of Oral Health and Diagnostic Sciences, Division of Periodontology, Center for Chemosensory Sciences, School of Dental Medicine, University of Connecticut Health Center, Farmington, CT 06030-1715, USA.
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Berthoud HR, Zheng H. Modulation of taste responsiveness and food preference by obesity and weight loss. Physiol Behav 2012; 107:527-32. [PMID: 22521912 DOI: 10.1016/j.physbeh.2012.04.004] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 03/30/2012] [Accepted: 04/03/2012] [Indexed: 12/12/2022]
Abstract
Palatable foods lead to overeating, and it is almost a forgone conclusion that it is also an important contributor to the current obesity epidemic - there is even talk about food addiction. However, the cause-effect relationship between taste and obesity is far from clear. As discussed here, there is substantial evidence for altered taste sensitivity, taste-guided liking and wanting, and neural reward processing in the obese, but it is not clear whether such traits cause obesity or whether obesity secondarily alters these functions. Studies with calorie restriction-induced weight loss and bariatric surgery in humans and animal models suggest that at least some of the obesity-induced alterations are reversible and consequently represent secondary effects of the obese state. Thus, both genetic and non-genetic predisposition and acquired alterations in taste and reward functions appear to work in concert to aggravate palatability-induced hyperphagia. In addition, palatability is typically associated with high energy content, further challenging energy balance regulation. The mechanisms responsible for these alterations induced by the obese state, weight loss, and bariatric surgery, remain largely unexplored. Better understanding would be helpful in designing strategies to promote healthier eating and prevention of obesity and the accompanying chronic disease risks.
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Affiliation(s)
- Hans-Rudolf Berthoud
- Neurobiology of Nutrition Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA.
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20
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Panek-Scarborough LM, Dewey AM, Temple JL. Sensation and perception of sucrose and fat stimuli predict the reinforcing value of food. Physiol Behav 2012; 105:1242-9. [DOI: 10.1016/j.physbeh.2012.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 01/03/2012] [Accepted: 01/04/2012] [Indexed: 01/17/2023]
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21
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Alhadeff AL, Rupprecht LE, Hayes MR. GLP-1 neurons in the nucleus of the solitary tract project directly to the ventral tegmental area and nucleus accumbens to control for food intake. Endocrinology 2012; 153:647-58. [PMID: 22128031 PMCID: PMC3275387 DOI: 10.1210/en.2011-1443] [Citation(s) in RCA: 311] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Central glucagon-like-peptide-1 (GLP-1) receptor activation reduces food intake; however, brain nuclei and mechanism(s) mediating this effect remain poorly understood. Although central nervous system GLP-1 is produced almost exclusively in the nucleus of the solitary tract in the hindbrain, GLP-1 receptors (GLP-1R) are expressed throughout the brain, including nuclei in the mesolimbic reward system (MRS), e.g. the ventral tegmental area (VTA) and the nucleus accumbens (NAc). Here, we examine the MRS as a potential site of action for GLP-1-mediated control of food intake and body weight. Double immunohistochemistry for Fluorogold (monosynaptic retrograde tracer) and GLP-1 neuron immunoreactivity indicated that GLP-1-producing nucleus tractus solitarius neurons project directly to the VTA, the NAc core, and the NAc shell. Pharmacological data showed that GLP-1R activation in the VTA, NAc core, and NAc shell decreased food intake, especially of highly-palatable foods, and body weight. Moreover, blockade of endogenous GLP-1R signaling in the VTA and NAc core resulted in a significant increase in food intake, establishing a physiological relevance for GLP-1 signaling in the MRS. Current data highlight these nuclei within the MRS as novel sites for GLP-1R-mediated control of food intake and body weight.
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Affiliation(s)
- Amber L Alhadeff
- Department of Psychiatry, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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22
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Shin AC, Townsend RL, Patterson LM, Berthoud HR. "Liking" and "wanting" of sweet and oily food stimuli as affected by high-fat diet-induced obesity, weight loss, leptin, and genetic predisposition. Am J Physiol Regul Integr Comp Physiol 2011; 301:R1267-80. [PMID: 21849633 DOI: 10.1152/ajpregu.00314.2011] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Cross-sectional studies in both humans and animals have demonstrated associations between obesity and altered reward functions at the behavioral and neural level, but it is unclear whether these alterations are cause or consequence of the obese state. Reward behaviors were quantified in male, outbred Sprague-Dawley (SD) and selected line obesity-prone (OP) and obesity-resistant (OR) rats after induction of obesity by high-fat diet feeding and after subsequent loss of excess body weight by chronic calorie restriction. As measured by the brief access lick and taste-reactivity paradigms, both obese SD and OP rats "liked" low concentrations of sucrose and corn oil less, but "liked" the highest concentrations more, compared with lean rats, and this effect was fully reversed by weight loss in SD rats. Acute food deprivation was unable to change decreased responsiveness to low concentrations but eliminated increased responsiveness to high concentrations in obese SD rats, and leptin administration in weight-reduced SD rats shifted concentration-response curves toward that seen in the obese state in the brief access lick test. "Wanting" and reinforcement learning as assessed in the incentive runway and progressive ratio lever-pressing paradigms was paradoxically decreased in both obese (compared with lean SD rats) and OP (compared with OR rats). Thus, reversible, obesity-associated, reduced "liking" and "wanting" of low-calorie foods in SD rats suggest a role for secondary effects of the obese state on reward functions, while similar differences between select lines of OP and OR rats before induction of obesity indicate a genetic component.
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Affiliation(s)
- Andrew C Shin
- Neurobiology of Nutrition Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA
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23
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Green BG, Nachtigal D, Hammond S, Lim J. Enhancement of retronasal odors by taste. Chem Senses 2011; 37:77-86. [PMID: 21798851 DOI: 10.1093/chemse/bjr068] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Psychophysical studies of interactions between retronasal olfaction and taste have focused most often on the enhancement of tastes by odors, which has been attributed primarily to a response bias (i.e., halo dumping). Based upon preliminary evidence that retronasal odors could also be enhanced by taste, the present study measured both forms of enhancement using appropriate response categories. In the first experiment, subjects rated taste ("sweet," "sour," "salty," and "bitter") and odor ("other") intensity for aqueous samples of 3 tastants (sucrose, NaCl, and citric acid) and 3 odorants (vanillin, citral, and furaneol), both alone and in taste-odor mixtures. The results showed that sucrose, but not the other taste stimuli, significantly increased the perceived intensity of all 3 odors. Enhancement of tastes by odors was inconsistent and generally weaker than enhancement of odors by sucrose. A second experiment used a flavored beverage and a custard dessert to test whether the findings from the first experiment would hold for the perception of actual foods. Adding sucrose significantly enhanced the intensity of "cherry" and "vanilla" flavors, whereas adding vanillin did not significantly enhance the intensity of sweetness. It is proposed that enhancement of retronasal odors by a sweet stimulus results from an adaptive sensory mechanism that serves to increase the salience of the flavor of nutritive foods.
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Affiliation(s)
- Barry G Green
- The John B. Pierce Laboratory, 290 Congress Avenue, New Haven, CT 06519, USA.
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Hajnal A, Kovacs P, Ahmed T, Meirelles K, Lynch CJ, Cooney RN. Gastric bypass surgery alters behavioral and neural taste functions for sweet taste in obese rats. Am J Physiol Gastrointest Liver Physiol 2010; 299:G967-79. [PMID: 20634436 PMCID: PMC2957340 DOI: 10.1152/ajpgi.00070.2010] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Roux-en-Y gastric bypass surgery (GBS) is the most effective treatment for morbid obesity. GBS is a restrictive malabsorptive procedure, but many patients also report altered taste preferences. This study investigated the effects of GBS or a sham operation (SH) on body weight, glucose tolerance, and behavioral and neuronal taste functions in the obese Otsuka Long-Evans Tokushima Fatty (OLETF) rats lacking CCK-1 receptors and lean controls (LETO). OLETF-GBS rats lost body weight (-26%) and demonstrated improved glucose tolerance. They also expressed a reduction in 24-h two-bottle preference for sucrose (0.3 and 1.0 M) and decreased 10-s lick responses for sucrose (0.3 through 1.5 M) compared with OLETF-SH or LETO-GBS. A similar effect was noted for other sweet compounds but not for salty, sour, or bitter tastants. In lean rats, GBS did not alter responses to any stimulus tested. Extracellular recordings from 170 taste-responsive neurons of the pontine parabrachial nucleus revealed a rightward shift in concentration responses to oral sucrose in obese compared with lean rats (OLETF-SH vs. LETO-SH): overall increased response magnitudes (above 0.9 M), and maximum responses occurring at higher concentrations (+0.46 M). These effects were reversed by GBS, and neural responses in OLETF-GBS were statistically not different from those in any LETO groups. These findings confirm obesity-related alterations in taste functions and demonstrate the ability of GBS to alleviate these impairments. Furthermore, the beneficial effects of GBS appear to be independent of CCK-1 receptor signaling. An understanding of the underlying mechanisms for reduced preferences for sweet taste could help in developing less invasive treatments for obesity.
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Affiliation(s)
- Andras Hajnal
- Dept. of Neural and Behavioral Sciences, The Milton S. Hershey Medical Center, The Pennsylvania State Univ., Hershey, PA 17033, USA.
| | | | | | | | - Christopher J. Lynch
- 3Department of Cellular and Molecular Physiology, The Milton S. Hershey Medical Center, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
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Abstract
Context Roux-en-Y gastric bypass surgery (RYGB) is currently the most effective treatment for morbid obesity and clinical studies suggest that RYGB patients change food preferences and the desire to eat. Objective To examine hedonic reactions to palatable foods and food choice behavior in an established rat model of Roux-en-Y gastric bypass surgery (RYGB). Methods and Design Male Sprague-Dawley rats and selected line obesity-prone rats that were rendered obese on a high-fat diet underwent RYGB or sham surgery and were tested for ‘liking’ and ‘wanting’ of palatable foods at different caloric densities 4 – 6 months after surgery. Results Compared with sham-operated (obese) and age-matched lean control rats, RYGB rats of both models exhibited more positive orofacial responses to low concentrations of sucrose but fewer to high concentrations. These changes in ‘liking’ by RYGB rats were translated into a shift of the concentration-response curve in the brief access test, with more vigorous licking of low concentrations of sucrose and corn oil, but less licking of the highest concentrations. The changes in hedonic evaluation also resulted in lower long-term preference/acceptance of high-fat diets compared with sham-operated (obese) rats. Furthermore, the reduced ‘wanting’ of a palatable reward in the incentive runway seen in sham-operated obese SD rats was fully restored after RYGB to the level found in lean control rats. Conclusions The results suggest that RYGB leads to a shift in hedonic evaluation, favoring low over high calorie foods and restores obesity-induced alterations in ‘liking’ and ‘wanting’. It remains to be determined whether these effects are simply due to weight loss or specific changes in gut-brain communication. Given the emerging evidence for modulation of cortico-limbic brain structures involved in reward mechanisms by gut hormones, RYGB-induced changes in the secretion of these hormones could potentially be mediating these effects.
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Affiliation(s)
- A C Shin
- Neurobiology of Nutrition Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA
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Mitra A, Gosnell BA, Schiöth HB, Grace MK, Klockars A, Olszewski PK, Levine AS. Chronic sugar intake dampens feeding-related activity of neurons synthesizing a satiety mediator, oxytocin. Peptides 2010; 31:1346-52. [PMID: 20399242 PMCID: PMC3175817 DOI: 10.1016/j.peptides.2010.04.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 04/06/2010] [Accepted: 04/07/2010] [Indexed: 01/08/2023]
Abstract
Increased tone of orexigens mediating reward occurs upon repeated consumption of sweet foods. Interestingly, some of these reward orexigens, such as opioids, diminish activity of neurons synthesizing oxytocin, a nonapeptide that promotes satiety and feeding termination. It is not known, however, whether consumption-related activity of the central oxytocin system is modified under chronic sugar feeding reward itself. Therefore, we examined how chronic consumption of a rewarding high-sucrose (HS) vs. bland cornstarch (CS) diet affected the activity of oxytocin cells in the hypothalamus at the time of meal termination. Schedule-fed (2h/day) rats received either a HS or CS powdered diet for 20 days. On the 21st day, they were given the same or the opposite diet, and food was removed after the main consummatory activity was completed. Animals were perfused 60 min after feeding termination and brains were immunostained for oxytocin and the marker of neuronal activity, c-Fos. The percentage of c-Fos-positive oxytocin cells in the hypothalamic paraventricular nucleus was significantly lower in rats chronically exposed to the HS than to the CS diet, regardless of which diet they received on the final day. A similar pattern was observed in the supraoptic nucleus. We conclude that the chronic rather than acute sucrose intake reduces activity of the anorexigenic oxytocin system. These findings indicate that chronic consumption of sugar blunts activity of pathways that mediate satiety. We speculate that a reduction in central satiety signaling precipitated by regular intake of foods high in sugar may lead to generalized overeating.
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Affiliation(s)
- Anaya Mitra
- Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave., St. Paul, MN 55108, USA.
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Abstract
The neurobiology of eating disorders (EDs) is largely unknown. However, brain imaging studies over the past decade have identified neurotransmitter alterations that could be part of dysfunctional behavior characteristics of EDs. In this chapter we focus on a specific behavioral construct, the brain reward system, and demonstrate a functional brain imaging approach toward identifying dopamine function in anorexia nervosa (AN). We demonstrate how human brain reward activation can be used in a translational approach to test whether computer models, based on basic science research, can predict expected in vivo reward system activation, and how such an approach can identify specific biologic alterations in a psychiatric population.
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Affiliation(s)
- Guido K W Frank
- Department of Psychiatry, Developmental Brain Research Program, University of Colorado Denver, The Children's Hospital, Gary Pavilion A036/B-130, 13123 East 16th Avenue, Aurora, CO 80045, USA.
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