Tags: Lowell Mason EssayExample Of A DissertationQuotes On EssaysFormat Of Review Of LiteratureThesis Statement About PhotographyPersonal Essays Or. Research Papers What Is The DifferenceSociety - A Complex Adaptive System Essays In Social Theory
The tight balance between energy demand and expenditure is fine-tuned by an adapted dialog between homeostatic and hedonic brain systems that are regulated by peripheral signals involved in feeding behavior and energy homeostasis. Mechanisms for feeding control remain a current and crucial scientific subject for understanding the etiology and potential therapeutic approaches for the treatment of food intake disorders that include obesity, on one hand, and severe forms of anorexia nervosa (AN) on the other.
In a recent review (Garcia et al., 2011), the lifetime prevalence of AN was estimated to be 1.9% in female adults to 2.6% in female adolescents in industrialized countries. Difference in susceptibility to activity-based anorexia in two inbred strains of mice.
In the binge eating/purging subtype, the individual engages in recurrent episodes of binge eating or purging behavior while such episodes do not occur in the restricting subtype.
Surprisingly, the plasma levels of ghrelin, an orexigenic hormone that drives food-motivated behavior, are increased.
This increase in plasma ghrelin levels seems paradoxical in light of the restrained eating adopted by AN patients, and may rather result from an adaptation to the disease.
Restrictive AN, mostly observed in young women, is the third largest cause of chronic illness in teenagers of industrialized countries.
From a neurobiological perspective, AN-linked behaviors can be considered an adaptation that permits the endurance of reduced energy supply, involving central and/or peripheral reprograming. The aim of this review is to describe the role played by ghrelin in AN focusing on its central vs. In AN patients and in rodent AN models, chronic food restriction induces profound alterations in the « ghrelin » signaling that leads to the development of inappropriate behaviors like hyperactivity or addiction to food starvation and therefore a greater depletion in energy reserves. The question of a transient insensitivity to ghrelin and/or a potential metabolic reprograming is discussed in regard of new clinical treatments currently investigated. The tissue distribution of the m RNA of ghrelin and subtypes of its receptor, GHS-R, in humans. Feeding is a behavior that ensures an adequate and varied supply of nutritional substrates essential to maintain energy levels for basal metabolism, physical activity, growth, and reproduction and hence, for survival of every living organism on Earth. In the case of mammals, that must maintain a stable body temperature, the maintenance of a high metabolic rate requires constant availability of a sufficient amount of energy stores. Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Gnanapavan, S., Kola, B., Bustin, S. Voluntary anorexia is a disease not unique to man and has even been described in many vertebrate species that favor migration activity (Wang et al., 2006). Pubmed Abstract | Pubmed Full Text Gianotti, L., Pincelli, A. In this case, surviving food deprivation involves an adaptation of metabolism, such that internal energy stores available at the onset of fasting are used to maintain basal metabolism and physical activity. I., Scacchi, M., Rolla, M., Bellitti, D., Arvat, E., et al. Effects of recombinant human insulin-like growth factor I administration on spontaneous and growth hormone (GH)-releasing hormone-stimulated GH secretion in anorexia nervosa. *-Indeed, many of its common primary characteristics – food obsession coupled with food restriction, weight loss, heightened physical activity, and the strong association with mood disorder (such as anxiety or depression), strongly suggest a potential alteration of the central (dopaminergic) reward system. Anorexia nervosa patients exhibit significant changes in the release of key hormones involved in energy balance and feeding control (Hasan and Hasan, 2011). The biochemical and physiological adaptations that result from a lack of food help to preserve physiological function in order to maintain behaviors like food seeking or predator avoidance and also, to resume all metabolic processes necessary when food becomes available. However, absolute or long term food deprivation observed in nature or in restrictive AN proceeds in stages in which the individual/organism tries to adapt its metabolism to energy costs but that culminates in death, due to exhaustion of energy stores. (2006), the different stages progress from fasting to starvation, but “The demarcation between these two states is rarely appreciated, perhaps owing to lack of definition.