scholarly journals Feeding behavior and entrainment limits in the circadian system of the rat

1998 ◽  
Vol 275 (2) ◽  
pp. R372-R383 ◽  
Author(s):  
J. A. Madrid ◽  
F. J. Sánchez-Vázquez ◽  
P. Lax ◽  
P. Matas ◽  
E. M. Cuenca ◽  
...  
Keyword(s):  
Food Intake ◽  
Feeding Behavior ◽  
Feeding Activity ◽  
Circadian System ◽  
The Other ◽  
Masking Effect ◽  
Meal Frequency ◽  
Feeding Duration ◽  
Feeding Rhythms ◽  
Number Of Cycles

The entrainment limits of the circadian rhythms of feeding activity were studied in Wistar rats exposed to gradually increasing and decreasing or to static light-dark cycles. In the former, the entrainment limits of feeding behavior were 22 h 10 min and 26 h 40 min. In the latter, the upper limit was higher, because rats under zeitgeber period ( t) length = 27 h ( t27) and t28 met the criteria of entrainment. The lower limit, on the other hand, was not modified because none of the t22 animals showed entrained rhythms and one-half of the t23 rats exhibited two components in their circadian feeding rhythms, one with a period of 23 h and the other free running. This 23-h component reflected not only the masking effect of light-dark cycles but also seemed a true light-entrained component. In well-synchronized animals, food intake seemed to depend more on the number of cycles that the animal experienced than on actual time lived; however, other feeding parameters, such as meal frequency and feeding duration, remained constant when expressed per 24 h, irrespective of the t cycle. These results concerning feeding duration, meal frequency, and food intake revealed that the homeostatic and circadian controls interacted to a degree that depended on the type of variable considered. In conclusion, the entrainment limits appeared much more imprecise than they were previously thought to be, because the circadian system can only be partially synchronized near its entrainment limits. The hypothesis that the rat’s circadian system is composed of multiple oscillators with different intrinsic frequencies and varying capacities for light synchronization would explain the partial desynchronization observed near the entrainment limits.

Feeding responses of rats with dorsomedial hypothalamic lesions given ip 2DG or glucose

1978 ◽  
Vol 235 (3) ◽  
pp. R168-R174
Author(s):  
L. L. Bellinger ◽  
L. L. Bernardis ◽  
S. Brooks
Keyword(s):  
Food Intake ◽  
Feeding Behavior ◽  
Food Consumption ◽  
The Other ◽  
Hypothalamic Nucleus ◽  
Saline Control ◽  
Other Hand ◽  
Dorsomedial Hypothalamic Nucleus ◽  
Pass Through ◽  
Bilateral Lesions

The glucoprivation effects of 2-deoxy-D-glucose (2DG) on feeding behavior were studied in rats with bilateral lesions of the dorsomedial hypothalamic nucleus (DMN) and sham-operated controls. The lesioned and sham-operated rats were injected intraperitoneally with 2DG (5% wt/vol) at doses of either 150 mg/kg, 300 mg/kg, or 500 mg/kg, or with saline ("control days"). At all doses significantly more sham-operated rats ate and showed an increased food consumption during the first few hours after 2DG injection when compared to saline control days. However, their 24-h food consumption was normal or less than normal, depending on the dose of 2DG. On the other hand, rats with DMN lesions (DMN-L) did not increase their food consumption during the 4 h after the injection at any of the 2DG doses. In a second experiment DMN-L and sham-operated controls were injected intraperitoneally with glucose (1.36 g/kg body wt or 2.72 g/kg body wt) or saline after an overnight fast. Glucose loads, compared to saline injections, significantly depressed the controls' food consumption only during the first hour of refeeding. On the other hand, glucose injections did not depress food intake of the DMN-L rats. It is suggested that DMN lesions may have either destroyed glucoreceptors in the DMN that monitor glucose or the glucoprivation effects caused by 2DG and/or glucoreceptive pathways that pass through the DMN.

scholarly journals Influence of 5-HT1A agonist on the feeding behavior of Coturnix japonica (Galliformes: Aves)

2005 ◽  
Vol 65 (4) ◽  
pp. 675-681 ◽  
Author(s):  
L. C. Reis ◽  
V. R. Marinho
Keyword(s):  
Food Intake ◽  
Feeding Behavior ◽  
Inhibitory Action ◽  
Serotonin Receptor ◽  
Previous Treatment ◽  
The Other ◽  
Coturnix Japonica ◽  
Beta Adrenergic ◽  
Other Hand

In this study, we investigate the effect of serotonin receptor 5-HT1A stimulation on the feeding behavior of quails (Coturnix japonica). The administration of 5-HT1A agonist, 8-OH-DPAT (0.05 to 5.0 mg/Kg) dose-dependently inhibited the food intake in normally fed quails. Greater inhibition was attained with 5.0 mg/kg (0.93 ± 0.21 g vs. 5.83 ± 0.25 g, P < 0.05, 2 h after food offer). A comparable response was obtained from previously fasted quails. At end of 2 h, a higher dose of 8-OH-DPAT induced more intense hypophagy (1.59 ± 0.41 g vs. 6.85 ± 1.04 g, P < 0.0001). Previous treatment with the antagonist 5-HT1A/beta-adrenergic, propranolol, failed to block the inhibitory action of 8-OH-DPAT, but instead, intensified it (controls, 5.22 ± 1.09 g; 8-OH-DPAT, 1.41 ± 0.19 g; propranolol + 8-OH-DPAT, 0.44 ± 0.25 g, P < 0.01, for all comparisons). The administration of an isolated higher dose of propranolol induced a hypophagic action (controls, 4.5 ± 0.8 g vs. propranolol, 2.0 ± 0.2 g, P < 0.01). Current outcomes suggest a possible role of 5-HT1A receptor on the feeding behavior of quails, as opposed to mammals. On the other hand, the intensified hypophagy induced by previous administration of propranolol raises the hypothesis of a beta-adrenergic excitatory mechanism that controls the feeding behavior of quails.

Effects of neurosecretory protein GL on food intake and fat accumulation under different dietary nutrient compositions in rats

2021 ◽  
Author(s):  
Keisuke Fukumura ◽  
Kenshiro Shikano ◽  
Yuaki Narimatsu ◽  
Eiko Iwakoshi-Ukena ◽  
Megumi Furumitsu ◽  
...  
Keyword(s):  
Food Intake ◽  
Feeding Behavior ◽  
Body Mass ◽  
Mass Gain ◽  
Chow Diet ◽  
Tissue Mass ◽  
Fat Accumulation ◽  
Intracerebroventricular Infusion ◽  
Body Mass Gain ◽  
Sucrose Diet

Abstract We recently identified a novel hypothalamic small protein, named neurosecretory protein GL (NPGL), which is involved in energy homeostasis in birds and mammals. However, whether the action of NPGL is influenced by nutritional composition remains unknown. Thus, we investigated the effect of chronic intracerebroventricular infusion of NPGL for 13 days on feeding behavior and body mass gain under a normal chow diet (NC), high-fat diet, high-sucrose diet (HSD), and medium-fat/medium-sucrose diet (MFSD) in rats. NPGL stimulated food intake of NC and MFSD, especially during the light period. By contrast, NPGL decreased body mass gain under NC and increased total white adipose tissue mass in HSD- and MFSD-fed rats. These data suggest that the effects of NPGL on feeding behavior, body mass gain, and fat accumulation depend on nutrient type. Among them, sucrose in diets seems to contribute to fat accumulation elicited by NPGL.

scholarly journals Impaired branched chain amino acid metabolism alters feeding behavior and increases orexigenic neuropeptide expression in the hypothalamus

2011 ◽  
Vol 212 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Megan N Purpera ◽  
Li Shen ◽  
Marzieh Taghavi ◽  
Heike Münzberg ◽  
Roy J Martin ◽  
...  
Keyword(s):  
Amino Acid ◽  
Food Intake ◽  
Feeding Behavior ◽  
Control Diet ◽  
Peripheral Tissues ◽  
Protein Status ◽  
Branched Chain Amino Acid ◽  
Branched Chain ◽  
Branched Chain Aminotransferase ◽  
Deficient Mice

Elevation of dietary or brain leucine appears to suppress food intake via a mechanism involving mechanistic target of rapamycin, AMPK, and/or branched chain amino acid (BCAA) metabolism. Mice bearing a deletion of mitochondrial branched chain aminotransferase (BCATm), which is expressed in peripheral tissues (muscle) and brain glia, exhibit marked increases in circulating BCAAs. Here, we test whether this increase alters feeding behavior and brain neuropeptide expression. Circulating and brain levels of BCAAs were increased two- to four-fold in BCATm-deficient mice (KO). KO mice weighed less than controls (25.9 vs 20.4 g,P<0.01), but absolute food intake was relatively unchanged. In contrast to wild-type mice, KO mice preferred a low-BCAA diet to a control diet (P<0.05) but exhibited no change in preference for low- vs high-protein (HP) diets. KO mice also exhibited low leptin levels and increased hypothalamicNpyandAgrpmRNA. Normalization of circulating leptin levels had no effect on either food preference or the increasedNpyandAgrpmRNA expression. If BCAAs act as signals of protein status, one would expect reduced food intake, avoidance of dietary protein, and reduction in neuropeptide expression in BCATm-KO mice. Instead, these mice exhibit an increased expression of orexigenic neuropeptides and an avoidance of BCAAs but not HP. These data thus suggest that either BCAAs do not act as physiological signals of protein status or the loss of BCAA metabolism within brain glia impairs the detection of protein balance.

scholarly journals GLP-2 receptor in POMC neurons suppresses feeding behavior and gastric motility

2012 ◽  
Vol 303 (7) ◽  
pp. E853-E864 ◽  
Author(s):  
Xinfu Guan ◽  
Xuemei Shi ◽  
Xiaojie Li ◽  
Benny Chang ◽  
Yi Wang ◽  
...  
Keyword(s):  
Gastric Emptying ◽  
Food Intake ◽  
Feeding Behavior ◽  
Gastric Motility ◽  
Late Onset ◽  
Physiological Role ◽  
Immune Defense ◽  
Melanocortin Receptor ◽  
Melanocortin System ◽  
Dorsomedial Nucleus

Glucagon-like peptides (GLP-1/2) are cosecreted from endocrine L cells in the gut and preproglucagonergic neurons in the brain. Peripheral GLP-2 action is essential for maintaining intestinal homeostasis, improving absorption efficiency and blood flow, promoting immune defense, and producing efficacy in treatment of gastrointestinal diseases. However, it is unknown if CNS GLP-2 plays a physiological role in the control of energy homeostasis. Since GLP-1/2 are cotranslated from preproglucagongene and coproduced by prohormone convertase-1, it is challenging to knockout GLP-2 only. Instead, our laboratory has generated a Glp2r-floxed mouse line to dissect cell-specific GLP-2 receptor GLP-2R) action in the regulation of energy balance. Our objective was to determine if GLP-2R in the hypothalamus modulates feeding behavior and gastric emptying. We show that Glp2r mRNA and protein are highly expressed in the arcuate nucleus and dorsomedial nucleus of the mouse hypothalamus. Using the Cre-LoxP system, we generated mice that lack Glp2r expression in POMC neurons (KO; mainly in the hypothalamus). The KO mice showed hyperphagic behavior (such as increases in food intake and meal frequency), accelerated gastric emptying (assessed by [13C]octanoic acid breath test), and late-onset obesity, yet there was no decrease in basal metabolic rate. Infusion of GLP-2 (2.5 nmol into the 4th ventricle) suppressed food intake and gastric emptying, while GLP-2-mediated effects were abolished in the melanocortin receptor-4 (MC4R) KO mice. We conclude that Glp2r deletion in POMC neurons enhances feeding behavior and gastric motility, whereas icv GLP-2R activation suppresses food intake and gastric emptying through the MC4R signaling pathway. This study indicates that CNS GLP-2R plays a physiological role in the control of feeding behavior and gastric emptying and that this is mediated probably through the melanocortin system.

Brain regulation of feeding behavior and food intake in fish

2000 ◽  
Vol 126 (4) ◽  
pp. 415-434 ◽  
Author(s):  
Xinwei Lin ◽  
Hélène Volkoff ◽  
Yuwaraj Narnaware ◽  
Nicholas J Bernier ◽  
Pierre Peyon ◽  
...  
Keyword(s):  
Food Intake ◽  
Feeding Behavior

Central and Peripheral Clock Control of Circadian Feeding Rhythms

2021 ◽  
pp. 074873042110458
Author(s):  
Carson V. Fulgham ◽  
Austin P. Dreyer ◽  
Anita Nasseri ◽  
Asia N. Miller ◽  
Jacob Love ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Circadian Clock ◽  
Feeding Behavior ◽  
Molecular Clock ◽  
Fat Body ◽  
Molecular Clocks ◽  
Central Brain ◽  
Feeding Rhythms ◽  
Free Running ◽  
The Brain

Many behaviors exhibit ~24-h oscillations under control of an endogenous circadian timing system that tracks time of day via a molecular circadian clock. In the fruit fly, Drosophila melanogaster, most circadian research has focused on the generation of locomotor activity rhythms, but a fundamental question is how the circadian clock orchestrates multiple distinct behavioral outputs. Here, we have investigated the cells and circuits mediating circadian control of feeding behavior. Using an array of genetic tools, we show that, as is the case for locomotor activity rhythms, the presence of feeding rhythms requires molecular clock function in the ventrolateral clock neurons of the central brain. We further demonstrate that the speed of molecular clock oscillations in these neurons dictates the free-running period length of feeding rhythms. In contrast to the effects observed with central clock cell manipulations, we show that genetic abrogation of the molecular clock in the fat body, a peripheral metabolic tissue, is without effect on feeding behavior. Interestingly, we find that molecular clocks in the brain and fat body of control flies gradually grow out of phase with one another under free-running conditions, likely due to a long endogenous period of the fat body clock. Under these conditions, the period of feeding rhythms tracks with molecular oscillations in central brain clock cells, consistent with a primary role of the brain clock in dictating the timing of feeding behavior. Finally, despite a lack of effect of fat body selective manipulations, we find that flies with simultaneous disruption of molecular clocks in multiple peripheral tissues (but with intact central clocks) exhibit decreased feeding rhythm strength and reduced overall food intake. We conclude that both central and peripheral clocks contribute to the regulation of feeding rhythms, with a particularly dominant, pacemaker role for specific populations of central brain clock cells.

scholarly journals Feeding behavior of lambs fed castor mealom farelo de mamona

2016 ◽  
Vol 37 (3) ◽  
pp. 1451 ◽  
Author(s):  
Hellenn Cardoso Oliveira ◽  
Rasmo Garcia ◽  
Vitor Visintin Silva de Almeida ◽  
Aline Cardoso Oliveira ◽  
Aureliano José Vieira Pires ◽  
...  
Keyword(s):  
Feeding Behavior ◽  
Soybean Meal ◽  
Feed Efficiency ◽  
Dry Matter ◽  
Feeding Activity ◽  
Experimental Period ◽  
Feeding Time ◽  
Adaptation Period ◽  
Four Levels ◽  
Castor Meal

The experiment aimed to evaluate the feeding behavior of Santa Inês lambs fed diets containing different levels of detoxified castor meal in the concentrate. Twenty-four sheep with an average body weight of 18.5± 2.26 kg, at four months of age, were distributed in a randomized complete design with four treatment and six replications. Treatments consisted of four levels of castor meal (0, 33, 67, and 100%) replacing soybean meal. Animals underwent a 15-day adaptation period and an experimental period of 84 days. The diet was composed of 60% sugarcane silage and 40% concentrate, on a dry matter basis. Animal behavior (idle, rumination, and feeding activities) were observed visually for two 24-h periods with 5-min intervals, and recorded. The number of rumination chews and the time taken to ruminate each cud per day were counted using a digital stopwatch. Dry matter (DM) intake was not affected by inclusion of castor meal in the concentrate, averaging 884.02 g day?1. The feeding activity was not affected by addition of castor meal. Rumination time increased linearly, whereas the idle and rumination times decreased linearly with addition of castor meal. Feeding time, expressed in min per kg of DM and NDF, was not influenced by the inclusion of the meal in the diet, averaging 373.3 and 880.0 min, respectively. The number of chews and the time taken to ruminate each cud were not changed by inclusion of castor meal in the diet. Feed efficiency, expressed in grams DM and NDF per hour, was not influenced by castor meal inclusion in the diet. Rumination efficiency expressed in g DM h?1 decreased, but was not affected when expressed in g NDF h?1. Total replacement of soybean meal by castor meal in the concentrate does not affect the feeding time or feed efficiency of feedlot sheep, but leads to a small reduction of their rumination efficiency. Thus, we recommend the inclusion of castor meal in sheep diets at the levels tested in this study.

Walking of Long Pipelines With Multiple Buckles: Can a Trend Be Trusted?

2018 ◽  
Author(s):  
Daniel Carneiro ◽  
Andrew Rathbone
Keyword(s):  
First Principles ◽  
Gradual Increase ◽  
Axial Displacement ◽  
The Other ◽  
Full Understanding ◽  
Other Hand ◽  
Operational Temperature ◽  
Number Of Cycles ◽  
Underlying Processes ◽  
Over Time

Walking of long pipelines with multiple buckles is usually self-limiting. The buckles break the ‘long’ pipeline into multiple ‘short’ ones that are prone to walk. However, as temperature decays over the length of the pipeline, the ‘short’ sections further downstream might become cyclically constrained and eventually anchor the full pipeline length. Walking of the hot end would then slow down and cease. This tapering down can take a large number of cycles, and not seem obvious when after a fair number of cycles, a small value of accumulated axial displacement per cycle is still observed in FEA. Often, designers would stop the analyses at some stage and assume the small rate will continue indefinitely. This can be overconservative, as a limit will often exist — which is demonstrated using first principles in the paper. On the other hand, extrapolating without full understanding of the underlying processes can be dangerous. For some particular conditions, the trend can suddenly change after continuing unaltered for many cycles. This paper illustrates such change in behavior with the example of a fictitious pipeline seeing a gentle, gradual increase in operational temperature over time. The exercise shows that, after the trend has apparently settled, at a given point the rate of walking can increase again. The conditions that trigger it are shown to be predictable.

scholarly journals Fish Feed Intake, Feeding Behavior, and the Physiological Response of Apelin to Fasting and Refeeding

2021 ◽  
Vol 12 ◽  
Author(s):  
Daniel Assan ◽  
Yanlin Huang ◽  
Umar Farouk Mustapha ◽  
Mercy Nabila Addah ◽  
Guangli Li ◽  
...  
Keyword(s):  
Food Intake ◽  
Feeding Behavior ◽  
Feed Intake ◽  
Production Efficiency ◽  
Great Influence ◽  
Physiological Mechanism ◽  
Fish Farming ◽  
Future Research ◽  
Fish Feed ◽  
Extrinsic Factors

Feed is one of the most important external signals in fish that stimulates its feeding behavior and growth. The intake of feed is the main factor determining efficiency and cost, maximizing production efficiency in a fish farming firm. The physiological mechanism regulating food intake lies between an intricate connection linking central and peripheral signals that are unified in the hypothalamus consequently responding to the release of appetite-regulating genes that eventually induce or hinder appetite, such as apelin; a recently discovered peptide produced by several tissues with diverse physiological actions mediated by its receptor, such as feed regulation. Extrinsic factors have a great influence on food intake and feeding behavior in fish. Under these factors, feeding in fish is decontrolled and the appetite indicators in the brain do not function appropriately thus, in controlling conditions which result in the fluctuations in the expression of these appetite-relating genes, which in turn decrease food consumption. Here, we examine the research advancements in fish feeding behavior regarding dietary selection and preference and identify some key external influences on feed intake and feeding behavior. Also, we present summaries of the results of research findings on apelin as an appetite-regulating hormone in fish. We also identified gaps in knowledge and directions for future research to fully ascertain the functional importance of apelin in fish.

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