The Experts below are selected from a list of 273 Experts worldwide ranked by ideXlab platform
T. Nisimura - One of the best experts on this subject based on the ideXlab platform.
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Experiential Effects of Appetitive and Nonappetitive Odors on Feeding Behavior in the Blowfly, Phormia regina: A Putative Role for Tyramine in Appetite Regulation
The Journal of Neuroscience, 2005Co-Authors: T. Nisimura, Atsushi Seto, Kyoko Nakamura, Mayumi Miyama, Takashi Nagao, Satoshi Tamotsu, Ryohei Yamaoka, Mamiko OzakiAbstract:In humans, Appetite is affected by food experiences and food flavors. In the blowfly Phormia regina , we found that feeding threshold to sugar Increased in the presence of the odor of d-limonene and decreased in the presence of the odor of dithiothreitol (DTT). Using these odors as representative nonappetitive and appetitive flavors, we demonstrated the role played by tyramine (TA) in Appetite regulation by experiences of food flavors. When fed with sucrose flavored with d-limonene for 5 d after emergence, flies showed subsequent decreased Appetite to plain sucrose, whereas when they were fed with sucrose flavored by DTT they showed Increased Appetite. However, mushroom body (MB)-ablated flies did not show these patterns. This suggests that MB, one of the primary memory centers of the insect brain, is necessary for the flies to apply previous experiences of food flavors to appetitive learning behaviors. In addition, flies' previously acquired decreased or Increased Appetites showed parallel changes with both octopamine (OA) and tyramine levels in the brain. However, injection experiments with OA, TA, or their agonist and antagonist indicated that TA more directly mediates feeding threshold determination, which was affected by acquired memories of food flavors.
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Experiential Effects of Appetitive and Nonappetitive Odors on Feeding Behavior in the Blowfly, Phormia regina: A Putative Role for Tyramine in Appetite Regulation
Journal of Neuroscience, 2005Co-Authors: T. NisimuraAbstract:In humans, Appetite is affected by food experiences and food flavors. In the blowfly Phormia regina, we found that feeding threshold to sugar Increased in the presence of the odor of D-limonene and decreased in the presence of the odor of dithiothreitol (DTT). Using these odors as representative nonappetitive and appetitive flavors, we demonstrated the role played by tyramine (TA) in Appetite regulation by experiences of food flavors. When fed with sucrose flavored with D-limonene for 5 d after emergence, flies showed subsequent decreased Appetite to plain sucrose, whereas when they were fed with sucrose flavored by DTT they showed Increased Appetite. However, mushroom body (MB)-ablated flies did not show these patterns. This suggests that MB, one of the primary memory centers of the insect brain, is necessary for the flies to apply previous experiences of food flavors to appetitive learning behaviors. In addition, flies' previously acquired decreased or Increased Appetites showed parallel changes with both octopamine (OA) and tyramine levels in the brain. However, injection experiments with OA, TA, or their agonist and antagonist indicated that TA more directly mediates feeding threshold determination, which was affected by acquired memories of food flavors. Copyright © 2005 Society for Neuroscience.
Pushpa S Kalra - One of the best experts on this subject based on the ideXlab platform.
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Increased Appetite augments hypothalamic npy y1 receptor gene expression effects of anorexigenic ciliary neurotropic factor
Regulatory Peptides, 1998Co-Authors: B Xu, Pushpa S Kalra, Lyle L Moldawer, Satya P KalraAbstract:Neuropeptide Y (NPY) is a potent endogenous Appetite transducer but the NPY receptor subtype mediating the induction of Appetite is unknown. Evaluation of hypothalamic NPY Y1 and Y5 receptor mRNA by RNase protection assay showed that Appetite evoked either by fasting or food-restriction Increased expression of Y1 mRNA. Suppression of Appetite by the cytokine, ciliary neurotropic factor, blocked this increase in Y1 gene expression. In contrast Y5 mRNA levels were unchanged by these treatments. These findings suggest that NPY-induced stimulation of Appetite requires signal transmission though Y1 receptor subtype in the hypothalamus.
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neuropeptide y secretion increases in the paraventricular nucleus in association with Increased Appetite for food
Proceedings of the National Academy of Sciences of the United States of America, 1991Co-Authors: Satya P Kalra, Michael G Dube, Abhiram Sahu, Christopher P Phelps, Pushpa S KalraAbstract:Feeding in mammals is a periodic behavior; however, knowledge of how the brain signals an intermittent eating pattern is scanty. Recent indirect evidence indicates that one of the signals encoded in the structure of neuropeptide Y (NPY) is to stimulate robust feeding. Therefore, two series of experiments were undertaken to characterize NPY secretion within the paraventricular nucleus (PVN) in association with eating behavior in the rat. Dynamic changes in NPY concentration in several hypothalamic sites and release in the PVN were assessed before and during the course of food consumption in rats trained to eat daily only for 4 h. Only in the PVN were NPY concentrations elevated before the introduction of food and, thereafter, levels decreased significantly during the course of eating. A similar temporal pattern in NPY release into the PVN interstitium was evident in samples collected by push-pull cannula perfusion in unrestrained rats. In addition, in food-deprived rats displaying a robust drive for feeding, NPY release in the PVN was also markedly enhanced in the shape of high-amplitude secretory episodes as compared to a lower release rate in rats receiving food ad libitum. The higher rate of NPY release in fasted rats returned to the control range after 24 h of ad libitum food supply. These findings of intense and dynamic NPY neurosecretory activity within a discrete hypothalamic site in association with an Increased drive for food consumption demonstrate that NPY release in the PVN is an important orexigenic signal for periodic eating behavior. These results have important global implications for elucidating the underlying causes of the pathophysiology of eating disorders--anorexia nervosa, bulimia, and obesity--as well as constituting a specific contextual model for the formulation and testing of suitable NPY receptor agonists and antagonists for therapeutic intervention.
Michael A Cowley - One of the best experts on this subject based on the ideXlab platform.
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repeated weight cycling in obese mice causes Increased Appetite and glucose intolerance
Physiology & Behavior, 2018Co-Authors: Stephanie E Simonds, Jack T Pryor, Michael A CowleyAbstract:Abstract Obesity is an ongoing global public health problem. For many people dieting is the preferred method of combating elevated body fat. Weight lost during caloric restriction is often soon regained and so a pattern of recurrent dieting develops. Here an individual's food intake fluctuates up and down with intermittent periods of normal eating and restrained eating. The metabolic consequences of ‘yoyo dieting’ or ‘weight cycling’ are not well understood. Here we monitor the effects of multiple, repeated dieting periods on body composition and metabolic health in overweight mice. Compared to mice that were continuously fed a high fat diet, the energy expenditure of diet-cycled mice was reduced. This resulted in mice rapidly regaining body weight upon the reintroduction of high fat chow diet subsequent to periods of caloric restriction. Diet cycling also Increased the Appetite for high fat chow and diminished glucose tolerance. These data demonstrate the detrimental effects of diet cycling upon metabolic health.
Kuniko Takagi - One of the best experts on this subject based on the ideXlab platform.
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anti ghrelin immunoglobulins modulate ghrelin stability and its orexigenic effect in obese mice and humans
Nature Communications, 2013Co-Authors: Kuniko Takagi, Romain Legrand, Akihiro Asakawa, Haruka Amitani, Marie Francois, Naouel Tennoune, Moise Coeffier, Sophie Claeyssens, Jeanclaude Do RegoAbstract:Obesity is often associated with Increased Appetite and food intake, despite normal blood levels of the hunger hormone ghrelin. Here the authors show that ghrelin-reactive antibodies in the blood of obese mice and humans enhance the orexigenic effect of ghrelin by protecting it from degradation.
J. L. Michaud - One of the best experts on this subject based on the ideXlab platform.
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Sim1 haploinsufficiency causes hyperphagia, obesity and reduction of the paraventricular nucleus of the hypothalamus
Human Molecular Genetics, 2001Co-Authors: J. L. MichaudAbstract:The bHLH-PAS transcription factor SIM1 is required for the development of the paraventricular nucleus (PVN) of the hypothalamus. Mice homozygous for a null allele of Sim1 (Sim1(-/-)) lack a PVN and die perinatally. In contrast, we show here that Sim1 heterozygous mice are viable but develop early-onset obesity, with Increased linear growth, hyperinsulinemia and hyperleptinemia. Sim1(+/-) mice are hyperphagic but their energy expenditure is not decreased, distinguishing them from other mouse models of early-onset obesity such as deficiencies in leptin and melanocortin receptor 4. Quantitative histological comparison with normal littermates showed that the PVN of Sim1(+/-) mice contains on average 24% fewer cells without a selective loss of any identifiable major cell type. Since acquired lesions in the PVN also induce Increased Appetite without a decrease in energy expenditure, we propose that abnormalities of PVN development cause the obesity of Sim1(+/-) mice. Severe obesity was described recently in a patient with a balanced translocation disrupting SIM1. Pathways controlling the development of the PVN thus have the potential to cause obesity in both mice and humans.
