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Perceptual and affective processing in appetite for foods
366
T.H. Moran / Appetite 51 (2010) 350–412
Genetic dissection of human taste perception A. FUSHAN 1,∗ , S. MCKLUSKEY 2 , C. SIMONS 2 , J. SLACK 2 , D. DRAYNA 1 . 1 NIDCD/National Institutes of Health, Rockville, USA 2 Givaudan Flavors Corp., Cincinnati, USA Inherited variation is an important source of differences in human taste perception. The paradigm for this variation has been large differences in the perceived bitterness of thiol-containing compounds exemplified by phenylthiocarbamide and propylthiouracil (PTC and PROP). We found that these compounds are sensed through the bitter receptor encoded by the TAS2R38 gene, which exists in two major forms, designated the major taster and major non-taster alleles, in populations worldwide. We have extended these genetic methods to other taste modalities, and recently applied them to variation in sweet taste perception. A naturally occurring form of the TAS1R2 gene, differing from the most common form at three amino acid positions, confers a reduced sensitivity to sweeteners in in vitro assays. Mutagenesis studies combined with in vitro functional analysis allows dissection of the relative contribution the three variant amino acids to receptor function, and provides insights into the mechanisms of sweet receptor signaling. More broadly, genetic association studies with candidate genes reveal additional genetic contributions to variation in sweet perception, and suggest that genetic variation in non-protein coding regions make major contributions to this phenotypic variation in the population. doi:10.1016/j.appet.2008.04.085
Perceptual and affective processing in appetite for foods J. GALEA 1,∗ , M. CHECHLACZ 1 , D.A. BOOTH 1 , S. HIGGS 1 , N. BIRBAUMER 2 , A. NOUWEN 1 . 1 Psychology, University of Birmingat T¨ ubingen, Tuebingen, ham, Edgbaston, United Kingdom 2 Universit¨ Germany Work using rated appetite, intake tests and brain imaging on eaten, pictured or named foods has confounded multifarious social, somatic and sensory attributes of a nutrient (such as fat or sugar) and relied erroneously on mere wordings of ratings of appetite to distinguish hunger or its satiety from so-called palatability, pleasure or reward. We report processing of information from pictures of foods that varied independently in fat and sugar contents and in sizes of portions. Such stimuli still confound diverse signals from each source of stimulation but the mental processes may be distinguishable by scaling the individual’s discrimination of stimulus levels from the learnt norm, shown for the taste of sugars in rats at SSIB’s predecessor 40 years ago. This personal cognitive diagnosis is sharpened by processing-analytical ratings in addition to overall appetite for each food—in this experiment, attraction or repulsion (valence) and degree of interest (arousal). Controls for colour and shape were non-food objects. In both healthy people and patients with type 2 diabetes, fat contents of the pictured foods generally had the greatest impact on rating of appetite, with sugar contents often contributing substantially and portion size playing only minor roles. Individuals varied widely, sometimes also across subsets of pictures, between perceptual processing driven by sight of a food and affective processing, tapped by valence and/or arousal. Such data on the specifics of ingestive cognition are essential to regional connectivities in imaging. doi:10.1016/j.appet.2008.04.087
The effects of oleoylethanolamide on feeding behaviour involve hypothalamic oxytocin neurons S. GAETANI 1,∗ , J. FU 2 , P. DIPASQUALE 1 , L. RIGHETTI 1 , V. CUOMO 1 , D. PIOMELLI 2 . 1 Department of Human Physiology and Pharmacology, University of Rome La Sapienza, Rome, Italy 2 Department of Pharmacology, University of California, Irvine, Irvine, USA Oleoylethanolamide (OEA) is the monounsaturated analogue of anandamide. Differently from anandamide, which causes overeating and stimulate lipogenesis by activating CB1 receptors, OEA decreases food intake and body weight gain in rats and mice through a cannabinoid receptor-independent mechanism. The effects of OEA on feeding are behaviourally selective and are due to the prolongation of feeding latency and post meal interval. A large body of evidence indicate that they are mediated by the activation of peripheral PPAR-alpha receptors, but the central mechanisms downstream to this activation are still unclear. Data obtained mapping brain c-fos mRNA levels revealed that the systemic administration of OEA evokes highly localized increase of c-fos transcription in the paraventricular nucleus (PVN) and the sopraoptic nucleus (SO). The magnocellular components of both nuclei release oxytocin, one of the anorectic hypothalamic neuropeptides, and we hypothesized that oxytocin neurons might play a key role in regulating energy intake after OEA administration. In agreement with our hypothesis, we found that OEA enhances the gene expression of oxytocin in both areas and that its anorexiant action can be prevented by pretreatment with a selective oxytocin receptor antagonist. Our data suggest that oxytocin release in the PVN and SO nuclei may be involved in the mediation of the effects induced by OEA on feeding. doi:10.1016/j.appet.2008.04.086
Sour and salty taste: A parametric study ´ A. GALINDO ∗ , A. LOPEZ-ESPINOZA, A.G. MART´ıNEZ, V. AGUILERA, ´ C. DE LA TORRE-IBARRA, M.L. GONZALEZ-TORRES, C.P. BELTRANMIRANDA. Feeding Behavior and Nutrition Research Center, CUSur, Universidad de Guadalajara, Zapotl´ an el Grande, Jalisco, Mexico Chemical properties of food like flavor, texture or odor provide information to organism on convenience of eating or avoiding a specific food. Some flavors like sweet and salty are accepted by an innate preference. On the other hand, acid and bitter are avoided. An element to consider is the concentration of flavor since it is an important factor for acceptance or rejection of a food. The objective of this experiment was to evaluate the effects of different concentrations from acid and salty flavors, using chloride of sodium and citric acid. Sixteen Wistar rats, eight females and eight males, were divided into two groups. They were exposed to twelve concentrations of citric acid or sodium chloride. Each group was divided into two sub-groups of four subjects each one, to which the concentrations in ascending or descendent order were given to them. Results indicated that low concentrations of citric acid and sodium chloride were consumed in greater proportion than high concentrations. This confirms that a flavor that is accepted to low concentrations can be rejected in high concentrations. doi:10.1016/j.appet.2008.04.088
T.H. Moran / Appetite 51 (2010) 350–412
Genetic dissection of human taste perception A. FUSHAN 1,∗ , S. MCKLUSKEY 2 , C. SIMONS 2 , J. SLACK 2 , D. DRAYNA 1 . 1 NIDCD/National Institutes of Health, Rockville, USA 2 Givaudan Flavors Corp., Cincinnati, USA Inherited variation is an important source of differences in human taste perception. The paradigm for this variation has been large differences in the perceived bitterness of thiol-containing compounds exemplified by phenylthiocarbamide and propylthiouracil (PTC and PROP). We found that these compounds are sensed through the bitter receptor encoded by the TAS2R38 gene, which exists in two major forms, designated the major taster and major non-taster alleles, in populations worldwide. We have extended these genetic methods to other taste modalities, and recently applied them to variation in sweet taste perception. A naturally occurring form of the TAS1R2 gene, differing from the most common form at three amino acid positions, confers a reduced sensitivity to sweeteners in in vitro assays. Mutagenesis studies combined with in vitro functional analysis allows dissection of the relative contribution the three variant amino acids to receptor function, and provides insights into the mechanisms of sweet receptor signaling. More broadly, genetic association studies with candidate genes reveal additional genetic contributions to variation in sweet perception, and suggest that genetic variation in non-protein coding regions make major contributions to this phenotypic variation in the population. doi:10.1016/j.appet.2008.04.085
Perceptual and affective processing in appetite for foods J. GALEA 1,∗ , M. CHECHLACZ 1 , D.A. BOOTH 1 , S. HIGGS 1 , N. BIRBAUMER 2 , A. NOUWEN 1 . 1 Psychology, University of Birmingat T¨ ubingen, Tuebingen, ham, Edgbaston, United Kingdom 2 Universit¨ Germany Work using rated appetite, intake tests and brain imaging on eaten, pictured or named foods has confounded multifarious social, somatic and sensory attributes of a nutrient (such as fat or sugar) and relied erroneously on mere wordings of ratings of appetite to distinguish hunger or its satiety from so-called palatability, pleasure or reward. We report processing of information from pictures of foods that varied independently in fat and sugar contents and in sizes of portions. Such stimuli still confound diverse signals from each source of stimulation but the mental processes may be distinguishable by scaling the individual’s discrimination of stimulus levels from the learnt norm, shown for the taste of sugars in rats at SSIB’s predecessor 40 years ago. This personal cognitive diagnosis is sharpened by processing-analytical ratings in addition to overall appetite for each food—in this experiment, attraction or repulsion (valence) and degree of interest (arousal). Controls for colour and shape were non-food objects. In both healthy people and patients with type 2 diabetes, fat contents of the pictured foods generally had the greatest impact on rating of appetite, with sugar contents often contributing substantially and portion size playing only minor roles. Individuals varied widely, sometimes also across subsets of pictures, between perceptual processing driven by sight of a food and affective processing, tapped by valence and/or arousal. Such data on the specifics of ingestive cognition are essential to regional connectivities in imaging. doi:10.1016/j.appet.2008.04.087
The effects of oleoylethanolamide on feeding behaviour involve hypothalamic oxytocin neurons S. GAETANI 1,∗ , J. FU 2 , P. DIPASQUALE 1 , L. RIGHETTI 1 , V. CUOMO 1 , D. PIOMELLI 2 . 1 Department of Human Physiology and Pharmacology, University of Rome La Sapienza, Rome, Italy 2 Department of Pharmacology, University of California, Irvine, Irvine, USA Oleoylethanolamide (OEA) is the monounsaturated analogue of anandamide. Differently from anandamide, which causes overeating and stimulate lipogenesis by activating CB1 receptors, OEA decreases food intake and body weight gain in rats and mice through a cannabinoid receptor-independent mechanism. The effects of OEA on feeding are behaviourally selective and are due to the prolongation of feeding latency and post meal interval. A large body of evidence indicate that they are mediated by the activation of peripheral PPAR-alpha receptors, but the central mechanisms downstream to this activation are still unclear. Data obtained mapping brain c-fos mRNA levels revealed that the systemic administration of OEA evokes highly localized increase of c-fos transcription in the paraventricular nucleus (PVN) and the sopraoptic nucleus (SO). The magnocellular components of both nuclei release oxytocin, one of the anorectic hypothalamic neuropeptides, and we hypothesized that oxytocin neurons might play a key role in regulating energy intake after OEA administration. In agreement with our hypothesis, we found that OEA enhances the gene expression of oxytocin in both areas and that its anorexiant action can be prevented by pretreatment with a selective oxytocin receptor antagonist. Our data suggest that oxytocin release in the PVN and SO nuclei may be involved in the mediation of the effects induced by OEA on feeding. doi:10.1016/j.appet.2008.04.086
Sour and salty taste: A parametric study ´ A. GALINDO ∗ , A. LOPEZ-ESPINOZA, A.G. MART´ıNEZ, V. AGUILERA, ´ C. DE LA TORRE-IBARRA, M.L. GONZALEZ-TORRES, C.P. BELTRANMIRANDA. Feeding Behavior and Nutrition Research Center, CUSur, Universidad de Guadalajara, Zapotl´ an el Grande, Jalisco, Mexico Chemical properties of food like flavor, texture or odor provide information to organism on convenience of eating or avoiding a specific food. Some flavors like sweet and salty are accepted by an innate preference. On the other hand, acid and bitter are avoided. An element to consider is the concentration of flavor since it is an important factor for acceptance or rejection of a food. The objective of this experiment was to evaluate the effects of different concentrations from acid and salty flavors, using chloride of sodium and citric acid. Sixteen Wistar rats, eight females and eight males, were divided into two groups. They were exposed to twelve concentrations of citric acid or sodium chloride. Each group was divided into two sub-groups of four subjects each one, to which the concentrations in ascending or descendent order were given to them. Results indicated that low concentrations of citric acid and sodium chloride were consumed in greater proportion than high concentrations. This confirms that a flavor that is accepted to low concentrations can be rejected in high concentrations. doi:10.1016/j.appet.2008.04.088