Anticipatory activity and entrainment of circadian rhythms in Syrian hamsters exposed to restricted palatable diets

1992 ◽  
Vol 263 (1) ◽  
pp. R116-R124 ◽  
Author(s):  
H. Abe ◽  
B. Rusak
Keyword(s):  
Circadian Rhythm ◽  
Food Restriction ◽  
Free Access ◽  
Circadian Pacemaker ◽  
Suprachiasmatic Nuclei ◽  
Experimental Animals ◽  
Daily Feeding ◽  
Free Running ◽  
Anticipatory Activity ◽  
Normal Food

Activity rhythms were recorded from hamsters in three conditions: during timed feedings of an attractive diet with free access to regular food, during restriction to 70% of normal food consumption, and during moderate food deprivation with limited temporal access to an attractive diet. An attractive diet given to intact animals did not induce anticipatory activity or entrainment, but damage to the suprachiasmatic nuclei (SCN) led to the development of anticipatory activity. Food restriction to 70% of normal intake led to anticipatory components in some intact animals, without entraining the dominant circadian pacemaker. The combination of a palatable diet and food restriction led to anticipatory activity before the daily feeding times and entrainment of a previously free-running circadian rhythm in some animals. Ablation of the SCN did not eliminate anticipatory activity in experimental animals, but did eliminate the free-running component of the rhythms. These results indicate that hamsters have a mechanism separate from the SCN that can anticipate daily feeding times, as rats do, and that they may show entrainment of the SCN-based pacemaker to such feeding schedules.

Restricted daily feeding during nursing period resets circadian locomotor rhythm of infant rats

1987 ◽  
Vol 252 (2) ◽  
pp. R262-R268
Author(s):  
S. Honma ◽  
K. Honma ◽  
T. Hiroshige
Keyword(s):  
Circadian Rhythm ◽  
Fixed Time ◽  
Feeding Time ◽  
Control Zone ◽  
Locomotor Rhythm ◽  
Daily Feeding ◽  
Rat Pups ◽  
Free Running ◽  
Phase Setting ◽  
Free Running Period

Phase setting of the circadian rhythm by restricted daily feeding (RF) was examined in rat pups. Feeding of virgin, pregnant, and nursing rats together with pups was restricted to 4 h at a fixed time of the day. Phases of the circadian rhythm developed in neonatally blinded pups were measured on the day of weaning to evaluate the effect of RF on phase setting. The activity onset and offset of the locomotor rhythm were used for the phase reference. In blinded pups born and raised under ad libitum feeding, the phase at weaning was a function of the free-running period measured after weaning and located in a narrow range (control zone). When RF was imposed from 2 wk prior to the conception (C) until weaning (3w), the pups phases were located outside the control zone and related to the feeding time. To identify the period in which the phase setting is effective, RF was imposed during 5 different periods (C-0w, C-1w, C-2w, 2-6w, and 3-6w). The circadian rhythm of all pups in the C-2w group and some in the C-1w was phase set, but those in other groups were not affected. It is concluded that RF imposed during the early nursing period is capable of phase setting the circadian system of blinded infant rats.x

Are membrane properties essential for the circadian rhythm of Gonyaulax?

1984 ◽  
Vol 247 (2) ◽  
pp. R250-R256
Author(s):  
H. G. Scholubbers ◽  
W. Taylor ◽  
L. Rensing
Keyword(s):  
Circadian Rhythm ◽  
Phase Shift ◽  
Fluorescence Polarization ◽  
The Other ◽  
Membrane Properties ◽  
Response Curves ◽  
Whole Cells ◽  
Different Temperatures ◽  
Free Running ◽  
Free Running Period

Membrane properties of whole cells of Gonyaulax polyedra were measured by fluorescence polarization. Circadian changes of fluorescence polarization exist in exponentially growing cultures. They show an amplitude larger than that of stationary cultures, indicating that a part of the change is due to or amplified by an ongoing cell cycle. Measurements of parameters of the circadian glow rhythm were analyzed for possible correlation with the membrane data. Considerable differences (Q10 = 2.5-3.0) in fluorescence polarization were found in cultures kept at different temperatures ranging from 15 to 27.5 degrees C. The free-running period length at different temperatures, on the other hand, differed only slightly (Q10 = 0.9-1.1). Stationary cultures showed higher fluorescence polarization compared with growing cultures, whereas the free-running period lengths did not differ in cultures of various densities and growth rates. Temperature steps of different sign changed the fluorescence polarization slightly in different directions. The phase shift of 4-h pulses (-5, -9, +7 degrees C) resulted in maximal phase advances of 4, 6, and 2 h, respectively. The phasing of the phase-response curves was identical in all these experiments, a finding not to be expected if the pulses act via the measured membrane properties. Pulses of drugs that change the fluorescence polarization (e.g., chlorpromazine and lidocaine) did not or only slightly phase-shift the circadian rhythm.

Effects of aging on entrainment and rate of resynchronization of circadian locomotor activity

1992 ◽  
Vol 263 (5) ◽  
pp. R1099-R1103 ◽  
Author(s):  
P. C. Zee ◽  
R. S. Rosenberg ◽  
F. W. Turek
Keyword(s):  
Circadian Rhythm ◽  
Locomotor Activity ◽  
Activity Rhythm ◽  
Phase Advance ◽  
Middle Aged ◽  
Age Related ◽  
Free Running ◽  
Effects Of Aging ◽  
Free Running Period ◽  
Related Phase

The phase angle of entrainment of the circadian rhythm of the locomotor activity rhythm to a light-dark (LD) cycle was examined in young (2-5 mo old) and middle-aged (13-16 mo old) hamsters. An age-related phase advance in the onset of locomotor activity relative to lights off was seen during stable entrainment to a 14:10-h LD cycle. In addition, the effects of age on the rate of reentrainment of the circadian rhythm of locomotor activity were examined by subjecting young and middle-aged hamsters to either an 8-h advance or delay shift of the LD cycle. Middle-aged hamsters resynchronized more rapidly after a phase advance of the LD cycle than did young hamsters, whereas young hamsters were able to phase delay more rapidly than middle-aged hamsters. The age-related phase advance of activity onset under entrained conditions, and the alteration of responses in middle-aged hamsters reentraining to a phase-shifted LD cycle, may be due to the shortening of the free-running period of the circadian rhythm of locomotor activity with advancing age that has previously been observed in this species.

Changes in body composition attendant on force feeding

1959 ◽  
Vol 196 (5) ◽  
pp. 965-968 ◽  
Author(s):  
Clarence Cohn ◽  
Dorothy Joseph
Keyword(s):  
Body Weight ◽  
Metabolic Pathways ◽  
Male Rats ◽  
Free Access ◽  
Carbohydrate Diet ◽  
Experimental Animals ◽  
Force Feeding ◽  
Feeding Regimen ◽  
Ad Libitum ◽  
Access To Food

Normal young adult male rats were either force-fed or allowed to eat ad libitum a moderate carbohydrate diet for 3–4 weeks. The force-fed animals were given either the amount of diet consumed by the animals eating ad libitum (pair-fed) or 80% of this amount (underfed). After a 2-week period of observation, we found that the rats eating ad libitum gained 65 gm of body weight, the pair-fed, force-fed 62 gm and the underfed, force-fed 40 gm. On the basis of the water, fat and protein content of the skin, viscera and carcass of control animals killed at the beginning of the feeding regimen and of similar constituents of the experimental animals after 2 weeks of feeding, the composition of the newly formed tissues of the various groups of animals consisted of the following: a) the rat with free access to food—water = 67.8%, fat = 7.8% and protein = 22.4%; b) the pair-fed, force-fed animal—water = 55.5%, fat = 23.6% and protein = 17.7%; c) the underfed, force-fed animal—water = 64.4%, fat = 7.9% and protein = 20.0%. The ratio of calories retained in newly formed tissue to the calories ingested over the 2-week period was 11.9% for the animals eating ad libitum, 20.6% for the pair-fed, force-fed animals and 9.5% for the underfed, force-fed rats. Force feeding appears to change intermediary metabolic pathways in the direction of increased ‘efficiency’ with resultant greater fat deposition.

Cortisol-mediated synchrinization of circadian rhythm in urinary potassium excretion

1977 ◽  
Vol 233 (5) ◽  
pp. R230-R238 ◽  
Author(s):  
M. C. Moore-ede ◽  
W. S. Schmelzer ◽  
D. A. Kass ◽  
J. A. Herd
Keyword(s):  
Circadian Rhythm ◽  
Saimiri Sciureus ◽  
Potassium Excretion ◽  
Dark Cycle ◽  
Urinary Potassium ◽  
Timing System ◽  
Daily Dose ◽  
Circadian Timing System ◽  
Free Running ◽  
Renal Potassium Excretion

Conscious chair-acclimatized squirrel monkeys (Saimiri sciureus) studied with lights on (600 lx) from 0800 to 2000 h daily (LD 12:12) display a prominent circadian rhythm in renal potassium excretion. The characteristics of this rhythm were reproduced in adrenalectomized monkeys by infusing 5 mg cortisol and 0.001 mg aldosterone, or 5 mg cortisol alone, between 0800 and 0900 h daily. When the timing of cortisol adminisration (with or without aldosterone) was phase-delayed by 8 h, the urinary potassium rhythm resynchronized by 80% of the cortisol phase shift, but only after a transient response lasting 3–4 days. With the same daily dose of adrenal steroids given as a continuous infusion throughout each 24 h, urinary potassium excretion showed free-running oscillations no longer synchronized to the light-dark cycle. These results indicate that the cirdacian rhythm of plasma cortisol concentration acts as an internal mediator in the circadian timing system, synchronizing a potentially autonomous oscillation in renal potassium excretion to environmental time cues and to other circadian rhythms within the animal.

scholarly journals Feeding Response of Tree Fodder Bhimal (Grewia optiva) on Growth Performance of Castrated Male Goats

2017 ◽  
Vol 3 ◽  
pp. 1-5
Author(s):  
Luma Nidhi Pandey ◽  
Megh Raj Tiwari ◽  
Bishnu Bahadur KC ◽  
Niraj Baskota ◽  
Jagan Nath Banjade
Keyword(s):  
Body Weight ◽  
Growth Performance ◽  
Dry Matter ◽  
Live Weight ◽  
Dry Matter Intake ◽  
Free Access ◽  
Experimental Animals ◽  
Mixture Treatment ◽  
Grewia Optiva ◽  
Concentrate Mixture

Bhimal (Grewia optiva) is a fodder tree mostly found in mid hills of mid and far western region of Nepal. Bhimal could constitutes one of the main livestock green fodders, especially for goats when fresh green fodder become limited during the winter dry season. However, the feeding value of Bhimal leaves on growth performance of castrated goats probably has not been evaluated so far. Therefore, an experiment was conducted to evaluate the effect of Bhimal leaves feeding on growth performance of castrated male goats for 90 days. Altogether 16 growing castrated male goats of same breed, age and body weight were selected and equally divided into four treatments T1, T2, T3 and T4 with four replications by using Completely Randomized Design (CRD). Four types of experimental diets were prepared having various levels (0 to 100%) of Bhimal leaves as fodder. Experimental animals of Treatment 1 were fed with seasonal fodder + 100 g concentrate mixture, Treatment 2 with 100% Bhimal fodder + 100 g concentrate mixture, Treatment 3with 75% Bhimal fodder + 25% seasonal fodder + 100 g concentrate mixture, while Treatment 4 with 50% Bhimal fodder + 50% season fodder + 100 g concentrate mixture. All diets were fed ad-lib and experimental animals had free access to drinking water. The diets offered and refusal was measured daily and weight change was observed fortnightly. The result showed that fodder intake (g/d/animal) and total dry matter intake (TDMI g/kg live weight) of goats differed significantly (P<0.01), but concentrate intake was not differed significantly (P<0.01) among treatments. The highest dry matter intake per animal /day was in Treatment 2 (52.75 g/kg live weight) followed by Treatment 4, Treatment 3 and Treatment 1 (51.7, 48.56 and 32.69 g/kg live weight, respectively).The average daily gain in body weight was observed highest in Treatment 2 (66.66 g/d) followed by Treatment 3 (31.66 g/d) and Treatment 4 (30.83 g). The growth rate was significantly (P<0.01) different among diet groups (P<0.05, P<0.01 and P<0.01 for 60, 75 and 90 days, respectively). In case of the feed conversion ratio, Treatment 2 had best ratio (8.79:1) than Treatment 1 (14.21:1), T3 (17.03:1) and Treatment 4 (18.59:1). The present response study showed that body weight in castrated male goats can be increased significantly (P<0.05) implying that in winter season when other green forages are poorly available goat farming  can be supported by Bhimal fodder tree.Journal of Nepal Agricultural Research Council Vol.3 2017: 1-11

scholarly journals Circadian Rhythm Sleep Disorders: Part II, Advanced Sleep Phase Disorder, Delayed Sleep Phase Disorder, Free-Running Disorder, and Irregular Sleep-Wake Rhythm

SLEEP ◽  
2007 ◽  
Vol 30 (11) ◽  
pp. 1484-1501 ◽  
Author(s):  
Robert L. Sack ◽  
Dennis Auckley ◽  
R. Robert Auger ◽  
Mary A. Carskadon ◽  
Kenneth P. Wright ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Sleep Disorders ◽  
Sleep Phase ◽  
Circadian Rhythm Sleep Disorders ◽  
Delayed Sleep Phase Disorder ◽  
Delayed Sleep Phase ◽  
Free Running ◽  
Delayed Sleep
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