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Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A retractable wire knife was used to transect medial or lateral components of the MFB or its lateral projections to the striatum and amygdaloid complex. All cuts produced significant depletions of NE, DA, and 5-HT from telencephalon and striatum but little or no effect on hypothalamic NE or 5-HT. Two of our cuts resulted in aphagia and adipsia, the third in hyperphagia and obesity. A detailed correlational analysis of the magnitude and direction of the behavioral and biochemical consequences of our cuts indicated that the ingestive behavior of all of our experimental animals (including animals which had been aphagic and adipsic after surgery as well as animals which were hyperphagic and obese) was positively correlated with the concentration of DA in striatum and telencephalon and negatively correlated with telencephalic 5-HT. Less consistent evidence for facilitatory noradrenergic influences on food intake was also obtained. Our results suggest that the regulation of food intake may be the result of an interaction between telencephalic serotonergic mechanisms and dopaminergic pathways which exert opposite effects on ingestive behavior.
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PMID:A correlational analysis of the effects of surgical transections of three components of the MFB on ingestive behavior and hypothalamic, striatal, and telencephalic amine concentrations. 30 Aug 83

The original conception of the hypothalamus controlling feeding by the activity of two specific and reciprocally inhibitory centers has now been largely abandoned. Detailed neural research using a wide variety of methods has demonstrated the complex morphological and functional organization of this part of the brain and has modified the earlier simplistic approach. However, examination of the feeding responses to a variety of stimuli that represent components of control of feeding indicates that much or even most feeding control is extrahypothalamic. As demonstrated by the obesity or aphagia resulting from hypothalamic damage or from reversible hypothalamic interference, the hypothalamus influences or modulates feeding control, possibly by an enabling action, but it does not itself substantially control food intake either in the short or the long term. In the cachaxia of cancer, which can tentatively be regarded as a negative obesity, and which is closely reproducible in a rat model, the decline of food intake can be attributed to failure of control components that are all extrahypothalamic, and the deterioration of control of feeding appears to be quite independent of the hypothalamus. The very detailed reconstruction of intrahypothalamic circuitry that has been developed in recent years has not yet had any real impact on the problem of where or how the active control of food intake is generated or the way in which the hypothalamus influences this control.
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PMID:The hypothalamic syndrome in rats. 32 49

Lateral hypothalamic lesions that produce aphagia reduce gastric retention and increase intestinal transit of a 10 ml liquid load in anesthetized rats. Ventromedial hypothalamic lesions which produce hyperphagia and obesity have the opposite effects. These results are apparent within minutes after lesioning as well as after postoperative stabilization of body weight (26--41 days). These data suggest that changes in gastrointestinal motor function(s) may contribute to the changes in food intake which follow hypothalamic damage.
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PMID:Differential effects of lateral and ventromedial hypothalamic lesions on gastrointestinal transit in the rat. 63 Apr 17

The neurological mechanisms associated with weight gain in animals have been extensively studied in mammals, but relatively little investigation has been carried out in birds. As in mammals, it has been shown that lesion of the ventromedial nucleus of the hypothalamus leads to hyperphagia and obesity in several species of birds. Likewise, bilateral lesions of the lateral hypothalamus result in aphagia and weight loss. Therefore, at the level of the hypothalamus, control of body weight appears to be controlled by similar neurological mechanisms in all homeothermic species via modulation of the sympathetic nervous system. Because of the role of the mammalian striatum in body weight regulation, body weight data from various manipulative studies in chickens were analyzed to see if these areas play a role in avian body weight regulation. In the first study, cycloheximide, glutamate, or saline was injected intracerebrally into 1-day-old chicks. In the second study, 3-day-old chicks received surgical ablation of the neocortex or kainic acid-induced lesions of the paleostriatum. Decreased body weight was noted in chicks that received injections of cycloheximide or glutamate, or kainic acid-induced lesions. The disruption in body weight in Experiment 1 might have been due to neurochemical pathology thought to occur in the paleostriatum. In the second experiment, lesions of the neostriatum or hyperstriatum, analogous to the neocortex in mammals, did not produce a difference in weight gain compared to controls. This preliminary work with kainic acid lesions in the chicken paleostriatum demonstrates a significant long-term decrease in body weight. As in mammals, the basal ganglia may have a role in body weight regulation.
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PMID:Avian telencephalon and body weight. 791 25

Feeding is a complex process responsive to sensory information related to sight and smell of food, previous feeding experiences, satiety signals elicited by ingestion and hormonal signals related to energy balance. Dopamine released in specific brain regions is associated with pleasurable and rewarding events and may reinforce positive aspects of feeding. Dopamine also influences initiation and coordination of motor activity and is required for sensorimotor functions. Thus, dopamine may facilitate integration of sensory cues related to hunger, initiating the search for food and its consumption. Dopaminergic neurons in the substantia nigra and ventral tegmental area project to the caudate putamen and nucleus accumbens, where they modulate movement and reward. There are projections from the nucleus accumbens to the lateral hypothalamus that regulate feeding. Dopamine-deficient mice (Dbh(Th/+), Th-/-; hereafter DD mice) cannot synthesize dopamine in dopaminergic neurons. They gradually become aphagic and die of starvation. Daily treatment of DD mice with L-3,4-dihydroxyphenylalanine (L-DOPA) transiently restores brain dopamine, locomotion and feeding. Leptin-null (Lep(ob/ob)) mice exhibit obesity, decreased energy expenditure and hyperphagia. As the hypothalamic leptin-melanocortin pathway appears to regulate appetite and metabolism, we generated mice lacking both dopamine and leptin (DD x Lep(ob/ob)) to determine if leptin deficiency overcomes the aphagia of DD mice. DD x Lep(ob/ob) mice became obese when treated daily with L-DOPA, but when L-DOPA treatment was terminated the double mutants were capable of movement, but did not feed. Our data show that dopamine is required for feeding in leptin-null mice.
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PMID:Dopamine is required for hyperphagia in Lep(ob/ob) mice. 1080 66

The hypothalamus is integral to the regulation of energy homeostasis and the secretion of hormones from the pituitary gland. Consequently, hypothalamic systems may have a dual purpose in regulating both neuroendocrine function and appetite. To date, most studies investigating the interface between appetite and hormone secretion have been performed in rats or mice that have been acutely fasted or baring a genetic abnormality causing either obesity or aphagia. By contrast, various physiological models, including chronic food-restriction or photoperiodically driven changes in voluntary food intake, add further perspective to the issue. In this regard, sheep provide an innovative model whereby long-term changes in body weight or extended feeding rhythms can be investigated. This review compares and contrasts data obtained in different species with regard to the neuroendocrinology of appetite, and discusses the benefits and knowledge gained from using various nonrodent models with a particular emphasis on a ruminant species.
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PMID:Links between the appetite regulating systems and the neuroendocrine hypothalamus: lessons from the sheep. 1278 54