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Saputra F, Lai YH, Fernandez RAT, Macabeo APG, Lai HT, Huang JC, Hsiao CD. Acute and Sub-Chronic Exposure to Artificial Sweeteners at the Highest Environmentally Relevant Concentration Induce Less Cardiovascular Physiology Alterations in Zebrafish Larvae. BIOLOGY 2021; 10:548. [PMID: 34207293 PMCID: PMC8233861 DOI: 10.3390/biology10060548] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 12/16/2022]
Abstract
Artificial sweeteners are widely used food ingredients in beverages and drinks to lower calorie intake which in turn helps prevent lifestyle diseases such as obesity. However, as their popularity has increased, the release of artificial sweetener to the aquatic environment has also increased at a tremendous rate. Thus, our study aims to systematically explore the potential cardiovascular physiology alterations caused by eight commercial artificial sweeteners, including acesulfame-K, alitame, aspartame, sodium cyclamate, dulcin, neotame, saccharine and sucralose, at the highest environmentally relevant concentration on cardiovascular performance using zebrafish (Danio rerio) as a model system. Embryonic zebrafish were exposed to the eight artificial sweeteners at 100 ppb and their cardiovascular performance (heart rate, ejection fraction, fractional shortening, stroke volume, cardiac output, heartbeat variability, and blood flow velocity) was measured and compared. Overall, our finding supports the safety of artificial sweetener exposure. However, several finding like a significant increase in the heart rate and heart rate variability after incubation in several artificial sweeteners are noteworthy. Biomarker testing also revealed that saccharine significantly increase the dopamine level in zebrafish larvae, which is might be the reason for the cardiac physiology changes observed after saccharine exposure.
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Affiliation(s)
- Ferry Saputra
- Department of Bioscience Technology, Chung Yuan Christian University, Taoyuan 320314, Taiwan;
| | - Yu-Heng Lai
- Department of Chemistry, Chinese Culture University, Taipei 11114, Taiwan;
| | - Rey Arturo T. Fernandez
- Laboratory for Organic Reactivity, Discovery and Synthesis (LORDS), Research Center for the Natural and Applied Sciences, University of Santo Tomas, Espana St., Manila 1015, Philippines; (R.A.T.F.); (A.P.G.M.)
| | - Allan Patrick G. Macabeo
- Laboratory for Organic Reactivity, Discovery and Synthesis (LORDS), Research Center for the Natural and Applied Sciences, University of Santo Tomas, Espana St., Manila 1015, Philippines; (R.A.T.F.); (A.P.G.M.)
| | - Hong-Thih Lai
- Department of Aquatic Biosciences, National Chiayi University, Chiayi 600355, Taiwan
| | - Jong-Chin Huang
- Department of Applied Chemistry, National Pingtung University, Pingtung 90003, Taiwan
| | - Chung-Der Hsiao
- Department of Bioscience Technology, Chung Yuan Christian University, Taoyuan 320314, Taiwan;
- Center for Nanotechnology, Chung Yuan Christian University, Taoyuan 320314, Taiwan
- Research Center for Aquatic Toxicology and Pharmacology, Chung Yuan Christian University, Taoyuan 320314, Taiwan
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2
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Kroemer NB, Veldhuizen MG, Delvy R, Patel BP, O'Malley SS, Small DM. Sweet taste potentiates the reinforcing effects of e-cigarettes. Eur Neuropsychopharmacol 2018; 28:1089-1102. [PMID: 30093174 DOI: 10.1016/j.euroneuro.2018.07.102] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 07/16/2018] [Accepted: 07/17/2018] [Indexed: 12/20/2022]
Abstract
Electronic cigarettes (e-cigarettes) are becoming increasingly popular. The popularity of fruit flavors among e-cigarette users suggests that sweet taste may contribute to e-cigarette appeal. We therefore tested whether sweet taste potentiates the reinforcing effects of nicotine. Using a conditioning paradigm adapted to study e-cigarettes, we tested whether exposure to flavored e-cigarettes containing nicotine plus sweet taste would be more reinforcing than unsweetened e-cigarettes. Sixteen light cigarette smokers smoked 4 distinctly colored e-cigarettes containing sweetened and unsweetened flavors with or without nicotine for 2 days each. Brain response was then assessed to the sight and smell of the 4 exposed e-cigarettes using fMRI. After exposure, sweet-paired flavors were wanted (p = .024) and tended to be liked (p = .053) more than nicotine-paired flavors. Moreover, sweet taste supra-additively increased liking for nicotine-paired flavors in individuals who did not show increased liking for nicotine alone (r = -.67, p = .005). Accordingly, cues predicting sweet compared to non-sweet flavors elicited a stronger response in the nucleus accumbens (NAcc, pSVC = .050) and the magnitude of response to the sight (pSVC = .022) and smell (pSVC = .017) of the e-cigarettes correlated with changes in liking. By contrast, the sight and smell of cues predicting nicotine alone failed to elicit NAcc response. However, the sight and smell of e-cigarettes paired with sweet+nicotine (pSVC = .035) produced supra-additive NAcc responses. Collectively, these findings demonstrate that sweet taste potentiates the reinforcing effects of nicotine in e-cigarettes resulting in heightened brain cue-reactivity.
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Affiliation(s)
- Nils B Kroemer
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA; The John B. Pierce Laboratory, New Haven, CT 06519, USA; Department of Psychiatry and Psychotherapy, University of Tübingen, 72076 Tübingen, Germany; Department of Psychiatry and Neuroimaging Center, Technische Universität Dresden, 01187 Dresden, Germany.
| | - Maria G Veldhuizen
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA; The John B. Pierce Laboratory, New Haven, CT 06519, USA
| | - Roberta Delvy
- The John B. Pierce Laboratory, New Haven, CT 06519, USA; School of Nursing, Yale University, Orange, CT 06477, USA
| | - Barkha P Patel
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA; The John B. Pierce Laboratory, New Haven, CT 06519, USA; Division of Endocrinology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Stephanie S O'Malley
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Dana M Small
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA; The John B. Pierce Laboratory, New Haven, CT 06519, USA; Department of Psychology, Yale University, New Haven, CT 06520, USA.
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3
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Musso PY, Lampin-Saint-Amaux A, Tchenio P, Preat T. Ingestion of artificial sweeteners leads to caloric frustration memory in Drosophila. Nat Commun 2017; 8:1803. [PMID: 29180783 PMCID: PMC5703724 DOI: 10.1038/s41467-017-01989-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 10/30/2017] [Indexed: 11/09/2022] Open
Abstract
Non-caloric artificial sweeteners (NAS) are widely used in modern human food, raising the question about their health impact. Here we have asked whether NAS consumption is a neutral experience at neural and behavioral level, or if NAS can be interpreted and remembered as negative experience. We used behavioral and imaging approaches to demonstrate that Drosophila melanogaster learn the non-caloric property of NAS through post-ingestion process. These results show that sweet taste is predictive of an energy value, and its absence leads to the formation of what we call Caloric Frustration Memory (CFM) that devalues the NAS or its caloric enantiomer. CFM formation involves activity of the associative memory brain structure, the mushroom bodies (MBs). In vivo calcium imaging of MB-input dopaminergic neurons that respond to sugar showed a reduced response to NAS after CFM formation. Altogether, these findings demonstrate that NAS are a negative experience for the brain. While non-caloric artificial sweeteners (NAS) are used as food additives, it’s unclear whether animals perceive NAS as positive or negative percept. Here, Musso and colleagues show in Drosophila that NAS is a negative percept, encoded in a new type of memory.
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Affiliation(s)
- Pierre-Yves Musso
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France.,Department of Zoology, Cell and Developmental Biology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z3
| | - Aurélie Lampin-Saint-Amaux
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France
| | - Paul Tchenio
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France.,Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, 91400, Orsay, France
| | - Thomas Preat
- Genes and Dynamics of Memory Systems, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 75005, Paris, France.
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Kim D, Chung S, Lee SH, Koo JH, Lee JH, Jahng JW. Decreased expression of 5-HT1A in the circumvallate taste cells in an animal model of depression. Arch Oral Biol 2017; 76:42-47. [PMID: 28119169 DOI: 10.1016/j.archoralbio.2017.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 01/11/2017] [Accepted: 01/12/2017] [Indexed: 01/22/2023]
Abstract
OBJECTIVE It has been reported that stress can cause anhedonia, a core symptom of depression, and also affect taste responses of the stressed subjects. Anhedonia refers to a reduction of the ability to experience pleasure, which can be detected by decreased response to palatable food in rats. The present study was conducted to examine if stress-induced anhedonia is accompanied by changes in gene expression for taste. DESIGN For anhedonia test, rats had free choices of cookies, a palatable food, and chow for 1h following 1h of daily restraint sessions. To examine the development of behavioral depression by restraint stress, ambulatory activity and forced swim tests were performed. Taste cells were harvested from the circumvallate papillae of rats on the 1st, 3rd and 7th day of stress exposure and subjected to the analysis of gene expression for taste. RESULTS One hour of daily stress exposure did not affect chow intake during the entire experimental period. However, from day 2 cookie intake was suppressed, suggesting the development of anhedonia. Ambulatory activity was significantly decreased, and immobility during forced swim test was increased, after the 7th day of stress exposure, but not before. 5-HT1A mRNA expression, but not T1R2, T1R3, T2R6, α-gustducin or PLCβ2 mRNA expression, appeared to be decreased after the 3rd day of stress exposure. CONCLUSION Reduced expression of 5-HT1A in the taste cells, possibly leading to a reduced processing of taste information for palatable food, may additively contribute to the development of anhedonia as a pre-symptomatic feature of depression in stressed subjects.
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Affiliation(s)
- Doyun Kim
- Dental Research Institute, Department of Oral and Maxillofacial Surgery, Seoul National University, School of Dentistry, Seoul, 110-768, South Korea; Department of Brain Science, Daegu Gyeongbuk Institute of Science & Technology, Daegu, 711-873, South Korea
| | - Sena Chung
- Dental Research Institute, Department of Oral and Maxillofacial Surgery, Seoul National University, School of Dentistry, Seoul, 110-768, South Korea
| | - Sung Ho Lee
- Dental Research Institute, Department of Oral and Maxillofacial Surgery, Seoul National University, School of Dentistry, Seoul, 110-768, South Korea
| | - Jae Hyung Koo
- Department of Brain Science, Daegu Gyeongbuk Institute of Science & Technology, Daegu, 711-873, South Korea
| | - Jong-Ho Lee
- Dental Research Institute, Department of Oral and Maxillofacial Surgery, Seoul National University, School of Dentistry, Seoul, 110-768, South Korea.
| | - Jeong Won Jahng
- Dental Research Institute, Department of Oral and Maxillofacial Surgery, Seoul National University, School of Dentistry, Seoul, 110-768, South Korea.
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5
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MCH receptor deletion does not impair glucose-conditioned flavor preferences in mice. Physiol Behav 2016; 163:239-244. [PMID: 27195455 DOI: 10.1016/j.physbeh.2016.05.024] [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: 02/17/2016] [Revised: 04/06/2016] [Accepted: 05/14/2016] [Indexed: 11/22/2022]
Abstract
The post-oral actions of glucose stimulate intake and condition flavor preferences in rodents. Hypothalamic melanin-concentrating hormone (MCH) neurons are implicated in sugar reward, and this study investigated their involvement in glucose preference conditioning in mice. In Exp. 1 MCH receptor 1 knockout (KO) and C57BL/6 wildtype (WT) mice learned to prefer 8% glucose over an initially more-preferred non-nutritive 0.1% sucralose+saccharin (S+S) solution. In contrast, the KO and WT mice preferred S+S to 8% fructose, which is consistent with this sugar's weak post-oral reinforcing action. In Exp. 2 KO and WT mice were trained to drink a flavored solution (CS+) paired with intragastric (IG) infusion of 16% glucose and a different flavored solution (CS-) paired with IG water. Both groups drank more CS+ than CS- in training and preferred the CS+ to CS- in a 2-bottle test. These results indicate that MCH receptor signaling is not required for flavor preferences conditioned by the post-oral actions of glucose. This contrasts with other findings implicating MCH signaling in other types of sugar reward processing.
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Sibille KT, Bartsch F, Reddy D, Fillingim RB, Keil A. Increasing Neuroplasticity to Bolster Chronic Pain Treatment: A Role for Intermittent Fasting and Glucose Administration? THE JOURNAL OF PAIN 2016; 17:275-81. [PMID: 26848123 DOI: 10.1016/j.jpain.2015.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 10/27/2015] [Accepted: 11/05/2015] [Indexed: 10/22/2022]
Abstract
UNLABELLED Neuroplastic changes in brain structure and function are not only a consequence of chronic pain but are involved in the maintenance of pain symptoms. Thus, promotion of adaptive, treatment-responsive neuroplasticity represents a promising clinical target. Emerging evidence about the human brain's response to an array of behavioral and environmental interventions may assist in identifying targets to facilitate increased neurobiological receptivity, promoting healthy neuroplastic changes. Specifically, strategies to maximize neuroplastic responsiveness to chronic pain treatment could enhance treatment gains by optimization of learning and positive central nervous system adaptation. Periods of heightened plasticity have been traditionally identified with the early years of development. More recent research, however, has identified a wide spectrum of methods that can be used to "reopen" and enhance plasticity and learning in adults. In addition to transcranial direct current stimulation and transcranial magnetic stimulation, behavioral and pharmacological interventions have been investigated. Intermittent fasting and glucose administration are two propitious strategies, that are noninvasive, inexpensive to administer, implementable in numerous settings, and might be applicable across differing chronic pain treatments. Key findings and neurophysiological mechanisms are summarized, and evidence for the potential clinical contributions of these two strategies toward ameliorating chronic pain is presented. PERSPECTIVE Neuroplastic changes are a defining feature of chronic pain and a complicating factor in treatment. Noninvasive strategies to optimize the brain's response to treatment interventions might improve learning and memory, increase the positive adaptability of the central nervous system, and enhance treatment outcomes.
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Affiliation(s)
- Kimberly T Sibille
- Department of Aging and Geriatric Research, University of Florida, Gainesville, Florida; Pain Research and Intervention Center of Excellence, University of Florida, Gainesville, Florida.
| | - Felix Bartsch
- Department of Aging and Geriatric Research, University of Florida, Gainesville, Florida; Pain Research and Intervention Center of Excellence, University of Florida, Gainesville, Florida; Department of Psychology, University of Florida, Gainesville, Florida
| | - Divya Reddy
- Pain Research and Intervention Center of Excellence, University of Florida, Gainesville, Florida
| | - Roger B Fillingim
- Pain Research and Intervention Center of Excellence, University of Florida, Gainesville, Florida
| | - Andreas Keil
- Department of Psychology, University of Florida, Gainesville, Florida
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7
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McNeill MS, Kapheim KM, Brockmann A, McGill TAW, Robinson GE. Brain regions and molecular pathways responding to food reward type and value in honey bees. GENES BRAIN AND BEHAVIOR 2016; 15:305-17. [PMID: 26566901 DOI: 10.1111/gbb.12275] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Revised: 10/27/2015] [Accepted: 11/10/2015] [Indexed: 12/19/2022]
Abstract
The ability of honey bees to evaluate differences in food type and value is crucial for colony success, but these assessments are made by individuals who bring food to the hive, eating little, if any, of it themselves. We tested the hypothesis that responses to food type (pollen or nectar) and value involve different subsets of brain regions, and genes responsive to food. mRNA in situ hybridization of c-jun revealed that brain regions responsive to differences in food type were mostly different from regions responsive to differences in food value, except those dorsal and lateral to the mushroom body calyces, which responded to all three. Transcriptomic profiles of the mushroom bodies generated by RNA sequencing gave the following results: (1) responses to differences in food type or value included a subset of molecular pathways involved in the response to food reward; (2) genes responsive to food reward, food type and food value were enriched for (the Gene Ontology categories) mitochondrial and endoplasmic reticulum activity; (3) genes responsive to only food and food type were enriched for regulation of transcription and translation; and (4) genes responsive to only food and food value were enriched for regulation of neuronal signaling. These results reveal how activities necessary for colony survival are channeled through the reward system of individual honey bees.
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Affiliation(s)
- M S McNeill
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - K M Kapheim
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Biology, Utah State University, Logan, UT, USA
| | - A Brockmann
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - T A W McGill
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - G E Robinson
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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8
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Ablation of TRPM5 in Mice Results in Reduced Body Weight Gain and Improved Glucose Tolerance and Protects from Excessive Consumption of Sweet Palatable Food when Fed High Caloric Diets. PLoS One 2015; 10:e0138373. [PMID: 26397098 PMCID: PMC4580452 DOI: 10.1371/journal.pone.0138373] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 08/27/2015] [Indexed: 01/09/2023] Open
Abstract
The calcium activated cation channel transient receptor potential channel type M5 (TRPM5) is part of the downstream machinery of the taste receptors and have been shown to play a central role in taste signalling. In addition it is also found in other types of chemosensory cells in various parts of the body as well as in pancreatic β-cells. The aim of this study was to investigate the effects of TRPM5 gene ablation on body weight, insulin sensitivity and other metabolic parameters in long-term high caloric diet induced obesity. Trpm5-/- mice gained significantly less body weight and fat mass on both palatable carbohydrate and fat rich cafeteria diet and 60% high fat diet (HFD) and developed less insulin resistance compared to wild type mice. A main finding was the clearly improved glucose tolerance in Trpm5-/- mice compared to wild type mice on cafeteria diet, which was independent of body weight. In addition, it was shown that Trpm5-/- mice consumed the same amount of calories when fed a HFD only or a HFD in combination with a palatable chocolate ball, which is in contrast to wild type mice that increased their caloric intake when fed the combination, mainly due to excessive consumption of the chocolate ball. Thus the palatable sugar containing diet induced overeating was prevented in Trpm5-/- mice. This indicates that sweet taste induced overeating may be a cause for the increased energy intake and glucose intolerance development seen for wild type mice on a sugar and high fat rich cafeteria diet compared to when on a high fat diet. This study point to an important role for the taste signalling system and TRPM5 in diet induced glucose intolerance.
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Cevik MÖ. Habituation, sensitization, and Pavlovian conditioning. Front Integr Neurosci 2014; 8:13. [PMID: 24574983 PMCID: PMC3920081 DOI: 10.3389/fnint.2014.00013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Accepted: 01/23/2014] [Indexed: 11/13/2022] Open
Abstract
In this brief review, I argue that the impact of a stimulus on behavioral control increase as the distance of the stimulus to the body decreases. Habituation, i.e., decrement in response intensity repetition of the triggering stimulus, is the default state for sensory processing, and the likelihood of habituation is higher for distal stimuli. Sensitization, i.e., increment in response intensity upon stimulus repetition, occurs in a state dependent manner for proximal stimuli that make direct contact with the body. In Pavlovian conditioning paradigms, the unconditioned stimulus (US) is always a more proximal stimulus than the conditioned stimulus (CS). The mechanisms of associative and non-associative learning are not independent. CS-US pairings lead to formation of associations if sensitizing modulation from a proximal US prevents the habituation for a distal anticipatory CS.
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10
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Sclafani A, Marambaud P, Ackroff K. Sucrose-conditioned flavor preferences in sweet ageusic T1r3 and Calhm1 knockout mice. Physiol Behav 2013; 126:25-9. [PMID: 24384370 DOI: 10.1016/j.physbeh.2013.12.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 10/19/2013] [Accepted: 12/12/2013] [Indexed: 01/06/2023]
Abstract
The present study compared the ability of sweet ageusic T1r3 knockout (KO) and Calhm1 KO mice to acquire preferences for a sucrose-paired flavor as well as for unflavored sucrose. The KO and wildtype (WT) mice were given 24-h one-bottle access to 8% sucrose containing one flavor CS+, e.g., grape) and to water containing a different flavor (CS-, e.g., cherry) over 4 training days. In subsequent two-bottle tests with the flavors in water only, the T1r3 KO and Calhm1 KO mice, like WT mice, preferred the CS+ to the CS-. After training with flavored solutions, both KO groups also preferred unflavored 8% sucrose to water although Calhm1 KO mice required more sugar experience to match the preference of the T1r3 KO mice. These findings demonstrate that Calhm1 KO mice, like T1r3 KO mice and WT mice, are sensitive to the post-oral preference conditioning actions of sucrose and can discriminate sugar from water. Yet, despite their acquired sucrose preferences, the Calhm1 KO and T1r3 KO mice consumed only half as much sugar per day as did WT mice. Thus, sweet taste signaling elements are not needed in the gut for sugar conditioning, but sweet taste signaling in the mouth is essential for the full expression of sugar appetite.
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Affiliation(s)
- Anthony Sclafani
- Department of Psychology, Brooklyn College, City University of New York, Brooklyn, NY 11210, USA.
| | - Philippe Marambaud
- Litwin-Zucker Research Center for the Study of Alzheimer's Disease, The Feinstein Institute for Medical Research, Manhasset, NY 11030, USA
| | - Karen Ackroff
- Department of Psychology, Brooklyn College, City University of New York, Brooklyn, NY 11210, USA
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11
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Itskov PM, Ribeiro C. The dilemmas of the gourmet fly: the molecular and neuronal mechanisms of feeding and nutrient decision making in Drosophila. Front Neurosci 2013; 7:12. [PMID: 23407678 PMCID: PMC3569668 DOI: 10.3389/fnins.2013.00012] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 01/21/2013] [Indexed: 11/13/2022] Open
Abstract
To survive and successfully reproduce animals need to maintain a balanced intake of nutrients and energy. The nervous system of insects has evolved multiple mechanisms to regulate feeding behavior. When animals are faced with the choice to feed, several decisions must be made: whether or not to eat, how much to eat, what to eat, and when to eat. Using Drosophila melanogaster substantial progress has been achieved in understanding the neuronal and molecular mechanisms controlling feeding decisions. These feeding decisions are implemented in the nervous system on multiple levels, from alterations in the sensitivity of peripheral sensory organs to the modulation of memory systems. This review discusses methodologies developed in order to study insect feeding, the effects of neuropeptides and neuromodulators on feeding behavior, behavioral evidence supporting the existence of internal energy sensors, neuronal and molecular mechanisms controlling protein intake, and finally the regulation of feeding by circadian rhythms and sleep. From the discussed data a conceptual framework starts to emerge which aims to explain the molecular and neuronal processes maintaining the stability of the internal milieu.
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Affiliation(s)
- Pavel M Itskov
- Behaviour and Metabolism Laboratory, Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown Lisbon, Portugal
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12
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Zukerman S, Ackroff K, Sclafani A. Post-oral glucose stimulation of intake and conditioned flavor preference in C57BL/6J mice: a concentration-response study. Physiol Behav 2012. [PMID: 23200639 DOI: 10.1016/j.physbeh.2012.11.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In a recent study, intragastric (IG) self-infusion of 16% glucose stimulated 1-h intake and conditioned a preference for a flavored saccharin solution in C57BL/6J mice (Zukerman et al., 2011). Experiment 1 of the present study presents a concentration-response analysis of IG glucose-induced intake stimulation monitored by recording licking response every min of the 1h/day sessions. Separate groups of food-restricted mice consumed a flavored saccharin solution (the CS-) paired with IG self-infusions of water (Test 0) followed by a different flavored solution (the CS+) paired with IG self-infusions of 2, 4, 8, 16, or 32% glucose (Tests 1-3). Following additional CS- and CS+ training sessions, a two-bottle CS+ vs. CS- choice test was conducted without infusions. Self-infusions of 8%, 16% or 32% glucose stimulated CS+ licking within 12 min of the first test session and even earlier in subsequent test sessions, and also conditioned significant CS+ preferences in the two-bottle test. The stimulation of early licking and CS+ preference increased as a function of glucose concentration. The amount of glucose solute self-infused increased with sugar concentration as did post-infusion blood glucose levels. The 2% glucose infusion did not stimulate CS+ intake and the 2% and 4% infusions failed to produce a CS+ preference in the 1-h test. Experiment 2 revealed that intraperitoneal self-infusions of 8% glucose, unlike IG glucose self-infusions, failed to stimulate CS+ licking or preference despite producing maximal increases in blood glucose levels. Taken together, these and other findings suggest that glucose rapidly produces concentration-dependent intestinal signals that stimulate intake and condition flavor preferences while post-oral satiation signals limit total amounts consumed.
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Affiliation(s)
- Steven Zukerman
- Department of Psychology, Brooklyn College, City University of New York, Brooklyn, 11210, USA
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Zukerman S, Ackroff K, Sclafani A. WITHDRAWN: Post-oral glucose stimulation of intake and conditioned flavor preference in C57BL/6J mice: A concentration-response study. Physiol Behav 2012:S0031-9384(12)00332-0. [PMID: 23582635 DOI: 10.1016/j.physbeh.2012.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 10/29/2012] [Indexed: 11/16/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Steven Zukerman
- Department of Psychology, Brooklyn College, City University of New York, Brooklyn, NY, USA 11210; Cognition, Brain, and Behavior Doctoral Subprogram, The Graduate School, City University of New York, New York, NY 10016, USA
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Gallo M, Rolls E. Chemosensory learning and memory. Front Syst Neurosci 2012; 6:73. [PMID: 23112766 PMCID: PMC3480658 DOI: 10.3389/fnsys.2012.00073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 10/05/2012] [Indexed: 11/24/2022] Open
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Dagher A. Functional brain imaging of appetite. Trends Endocrinol Metab 2012; 23:250-60. [PMID: 22483361 DOI: 10.1016/j.tem.2012.02.009] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Revised: 02/22/2012] [Accepted: 02/28/2012] [Indexed: 01/01/2023]
Abstract
Obesity is a neurobehavioral disorder that results from a combination of overeating and insufficient physical activity. Finely tuned mechanisms exist to match food intake to caloric expenditure. However, faced with abundant inexpensive and calorie-dense foods, many humans (and perhaps most) have a tendency to consume beyond their caloric needs. The brain controls food intake by sensing internal energy-balance signals and external cues of food availability, and by controlling feeding behavior; it is therefore at the centre of the obesity problem. This article reviews the recent use of functional brain imaging in humans to study the neural control of appetite, and how the neural systems involved may cause vulnerability to overeating in the obesogenic environment.
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Affiliation(s)
- Alain Dagher
- Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, Quebec, H3A 2B4, Canada.
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