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Loss of affect for foods in patients with anorexia nervosa
666
Abstracts / Appetite 54 (2010) 631–683
Rats learn stronger preferences for flavors occurring late in a high-fat meal K.P. MYERS Bucknell University, Lewisburg, PA, USA Rats learn to prefer flavors that are paired with the postingestive effects of macronutrients. It has been suggested that flavors routinely consumed late in a meal (desserts) may become more strongly preferred because they are most closely associated with delayed postingestive effects of the entire meal. To the contrary, we have previously found that rats learn similar preference for flavors occurring both early and late in a carbohydrate (glucose) meal, indicating that relevant postingestive events are rapidly detected. The present study investigated learning about early and late flavors when the calorie source is fat. Rats (n = 16) with gastric catheters repeatedly experienced two types of training sessions: in (+) meals, they consumed non-caloric cue flavors paired with intragastric (IG) infusion of high-fat solution (heavy cream diluted in water, 0.5 kcal/g); in (−) meals flavors were accompanied by IG water infusion. In each type of session, one flavor (E) always occurred in the Early half (8 min) and another flavor (L) in the Late half of the meal. Thus each rat was trained with four flavors: E+ and L+, E− and L−. Subsequent two-bottle choice tests were conducted to assess whether rats learned flavor preferences based on flavor-nutrient associations. Rats preferred the L+ but not E+ flavor, supporting the idea that flavors occurring late in the meal become most strongly associated with delayed postingestive effects of fat. Unexpectedly, the preference for L+ was even stronger when rats were tested shortly after chow feeding than when they were tested food deprived. doi:10.1016/j.appet.2010.04.148
Loss of affect for foods in patients with anorexia nervosa J.A. NASSER 1,2,∗ , H.R. KISSILEFF 1 , T. OBERNDORFER 3 , W.H. KAYE 3 1 St. Luke’s/Roosevelt Hospital Center, New York, NY, USA 2 Drexel University, Philadelphia, PA, USA 3 UC San Diego, San Diego, CA, USA High sugar and/or fat foods tend to cause release of dopamine and promote consumption of food. Over activity of the dopamine reward circuitry has been found in recovered anorexia nervosa (AN) patients. If AN patients restrict food intake because “pleasant” stimuli provoke excessive dopamine release and anxiety, AN patients might be coaxed into eating substantial amounts of foods that control subjects find unpalatable or disgusting. This possibility was tested in a brief exposure taste test in which eight control women and eight ILLRAN tasted 28-g servings of foods prejudged by the experimenters as palatable “PAL” or unpalatable “UNP”, (eight of each type), eating as much or as little as they liked and giving a rating of each on a 9-point scale of liking. PAL foods included string cheese and chocolate pudding and UNP foods included gelatinized bread and elemental amino acids. Patients ate slightly more (3.3 ± 5, F = 3.3, P = 0.1) total grams of UNP foods (11.9 ± 11.5) than PAL foods (8.6 ± 6.7) and rated both types of foods as marginally palatable (5.0 = PAL and 3.0 = UNP). Controls ate less UNP food (21.1 ± 14.6) than PAL (34.3 ± 21.2) and the difference was significant (F = 6.8, P = 0.035). The between group PAL-UNP food intake difference was highly significant (F = 9.4, P = 0.008) Controls rated the PAL (M = 7.6 ± 1.5) food significantly more liked by 4.5 ± 0.4, (P < 0.001) than the unpalatable (M = 3.0 ± 2.3). The prediction that AN patients will eat more UNP than PAL food is promising and suggests that making high energy foods unpalatable might be an effective strategy to induce AN patients to eat. doi:10.1016/j.appet.2010.04.150
Visceral NTS projections to nucleus intermedius J.S. NASSE ∗ , S.P. TRAVERS, J.B. TRAVERS OSU, Columbus, USA The medullary reticular formation is involved in coordinating and modulating basic survival behaviors such as breathing and the oromotor phase of ingestion. Recent evidence implicates the reticular area adjacent to the hypoglossal motor nucleus (mXII), the intermedius nucleus of the medulla (ImN), as a potential region for integrating multiple afferent sensory signals (Edwards et al., 2009). Moreover, previous retrograde tracing studies demonstrate that ImN neurons send axons to mXII, consistent with a role in oromotor function. Using anterograde fluorescent tracers we demonstrate that the ImN receives afferent projections from both the rostral and caudal nucleus of the solitary tract (rNTS, cNTS). To further study the inputs and outputs of the ImN, we injected mXII with a retrograde tracer in neonatal rat pups prior to patch clamp recordings in a slice preparation. Traced ImN neurons displayed time-locked inhibitory and excitatory post-synaptic currents (IPSCs, EPSCs) in response to electrical stimulation of the cNTS. In some ImN neurons, there was also an increase in driven miniature EPSCs or IPSCs following short trains of stimulation. Pharmacologic antagonism of ionotropic glutamate receptors blocked only some EPSCs indicating multiple excitatory phenotypes. Together, these results suggest that the ImN may act as a substrate for convergence of gustatory signals from the rNST and visceral signals from the neurochemically diverse cNST. These data are consistent with the hypothesis that the ImN integrates multiple afferent signals through complex synaptic mechanisms to coordinate diverse oromotor behaviors. Supported by NIH DC000416 and DC000417. doi:10.1016/j.appet.2010.04.149
Development of food preferences in early childhood S. NICKLAUS Centre des Sciences du Goût et de l’Alimentation, Dijon, France At the beginning of life, major transitions occur in feeding mode within very few years, with the human infant switching from cord feeding in utero to milk feeding, going through weaning and complementary food introduction to ultimately eating foods from the family table, which is generally achieved before his/her second birthday. This poses two general questions. First, one might search to understand the factors which favour the transitions from one feeding mode to the next, or which favour food acceptance at a certain stage. Second, one might like to understand the consequences of these early feeding experiences on preference for specific foods and on food temperament. The first question will be discussed in particular by analysing the role of milk-related feeding experience on food acceptance of weaning. Certain individual factors will also be considered such as the impact of taste acceptance on acceptance of weaning foods. More generally, the role of taste on food intake will be discussed. The second question will be addressed based on results from longitudinal studies underlying the impact of exposure to a variety of foods on further food acceptance, and also considering the role of parental feeding practices on children’s feeding temperament, including selectivity and neophobia. doi:10.1016/j.appet.2010.04.151
Abstracts / Appetite 54 (2010) 631–683
Rats learn stronger preferences for flavors occurring late in a high-fat meal K.P. MYERS Bucknell University, Lewisburg, PA, USA Rats learn to prefer flavors that are paired with the postingestive effects of macronutrients. It has been suggested that flavors routinely consumed late in a meal (desserts) may become more strongly preferred because they are most closely associated with delayed postingestive effects of the entire meal. To the contrary, we have previously found that rats learn similar preference for flavors occurring both early and late in a carbohydrate (glucose) meal, indicating that relevant postingestive events are rapidly detected. The present study investigated learning about early and late flavors when the calorie source is fat. Rats (n = 16) with gastric catheters repeatedly experienced two types of training sessions: in (+) meals, they consumed non-caloric cue flavors paired with intragastric (IG) infusion of high-fat solution (heavy cream diluted in water, 0.5 kcal/g); in (−) meals flavors were accompanied by IG water infusion. In each type of session, one flavor (E) always occurred in the Early half (8 min) and another flavor (L) in the Late half of the meal. Thus each rat was trained with four flavors: E+ and L+, E− and L−. Subsequent two-bottle choice tests were conducted to assess whether rats learned flavor preferences based on flavor-nutrient associations. Rats preferred the L+ but not E+ flavor, supporting the idea that flavors occurring late in the meal become most strongly associated with delayed postingestive effects of fat. Unexpectedly, the preference for L+ was even stronger when rats were tested shortly after chow feeding than when they were tested food deprived. doi:10.1016/j.appet.2010.04.148
Loss of affect for foods in patients with anorexia nervosa J.A. NASSER 1,2,∗ , H.R. KISSILEFF 1 , T. OBERNDORFER 3 , W.H. KAYE 3 1 St. Luke’s/Roosevelt Hospital Center, New York, NY, USA 2 Drexel University, Philadelphia, PA, USA 3 UC San Diego, San Diego, CA, USA High sugar and/or fat foods tend to cause release of dopamine and promote consumption of food. Over activity of the dopamine reward circuitry has been found in recovered anorexia nervosa (AN) patients. If AN patients restrict food intake because “pleasant” stimuli provoke excessive dopamine release and anxiety, AN patients might be coaxed into eating substantial amounts of foods that control subjects find unpalatable or disgusting. This possibility was tested in a brief exposure taste test in which eight control women and eight ILLRAN tasted 28-g servings of foods prejudged by the experimenters as palatable “PAL” or unpalatable “UNP”, (eight of each type), eating as much or as little as they liked and giving a rating of each on a 9-point scale of liking. PAL foods included string cheese and chocolate pudding and UNP foods included gelatinized bread and elemental amino acids. Patients ate slightly more (3.3 ± 5, F = 3.3, P = 0.1) total grams of UNP foods (11.9 ± 11.5) than PAL foods (8.6 ± 6.7) and rated both types of foods as marginally palatable (5.0 = PAL and 3.0 = UNP). Controls ate less UNP food (21.1 ± 14.6) than PAL (34.3 ± 21.2) and the difference was significant (F = 6.8, P = 0.035). The between group PAL-UNP food intake difference was highly significant (F = 9.4, P = 0.008) Controls rated the PAL (M = 7.6 ± 1.5) food significantly more liked by 4.5 ± 0.4, (P < 0.001) than the unpalatable (M = 3.0 ± 2.3). The prediction that AN patients will eat more UNP than PAL food is promising and suggests that making high energy foods unpalatable might be an effective strategy to induce AN patients to eat. doi:10.1016/j.appet.2010.04.150
Visceral NTS projections to nucleus intermedius J.S. NASSE ∗ , S.P. TRAVERS, J.B. TRAVERS OSU, Columbus, USA The medullary reticular formation is involved in coordinating and modulating basic survival behaviors such as breathing and the oromotor phase of ingestion. Recent evidence implicates the reticular area adjacent to the hypoglossal motor nucleus (mXII), the intermedius nucleus of the medulla (ImN), as a potential region for integrating multiple afferent sensory signals (Edwards et al., 2009). Moreover, previous retrograde tracing studies demonstrate that ImN neurons send axons to mXII, consistent with a role in oromotor function. Using anterograde fluorescent tracers we demonstrate that the ImN receives afferent projections from both the rostral and caudal nucleus of the solitary tract (rNTS, cNTS). To further study the inputs and outputs of the ImN, we injected mXII with a retrograde tracer in neonatal rat pups prior to patch clamp recordings in a slice preparation. Traced ImN neurons displayed time-locked inhibitory and excitatory post-synaptic currents (IPSCs, EPSCs) in response to electrical stimulation of the cNTS. In some ImN neurons, there was also an increase in driven miniature EPSCs or IPSCs following short trains of stimulation. Pharmacologic antagonism of ionotropic glutamate receptors blocked only some EPSCs indicating multiple excitatory phenotypes. Together, these results suggest that the ImN may act as a substrate for convergence of gustatory signals from the rNST and visceral signals from the neurochemically diverse cNST. These data are consistent with the hypothesis that the ImN integrates multiple afferent signals through complex synaptic mechanisms to coordinate diverse oromotor behaviors. Supported by NIH DC000416 and DC000417. doi:10.1016/j.appet.2010.04.149
Development of food preferences in early childhood S. NICKLAUS Centre des Sciences du Goût et de l’Alimentation, Dijon, France At the beginning of life, major transitions occur in feeding mode within very few years, with the human infant switching from cord feeding in utero to milk feeding, going through weaning and complementary food introduction to ultimately eating foods from the family table, which is generally achieved before his/her second birthday. This poses two general questions. First, one might search to understand the factors which favour the transitions from one feeding mode to the next, or which favour food acceptance at a certain stage. Second, one might like to understand the consequences of these early feeding experiences on preference for specific foods and on food temperament. The first question will be discussed in particular by analysing the role of milk-related feeding experience on food acceptance of weaning. Certain individual factors will also be considered such as the impact of taste acceptance on acceptance of weaning foods. More generally, the role of taste on food intake will be discussed. The second question will be addressed based on results from longitudinal studies underlying the impact of exposure to a variety of foods on further food acceptance, and also considering the role of parental feeding practices on children’s feeding temperament, including selectivity and neophobia. doi:10.1016/j.appet.2010.04.151