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.

scholarly journals Response curve, free-running period, and activity time in circadian locomotor rhythm of rats.

1985 ◽  
Vol 35 (4) ◽  
pp. 643-658 ◽  
Author(s):  
Ken-ichi HONMA ◽  
Sato HONMA ◽  
Tsutomu HIROSHIGE
Keyword(s):  
Response Curve ◽  
Activity Time ◽  
Locomotor Rhythm ◽  
Free Running ◽  
Free Running Period

Phase setting of circadian locomotor rhythm of infant rats

1987 ◽  
Vol 252 (2) ◽  
pp. R256-R261
Author(s):  
K. Honma ◽  
S. Honma ◽  
T. Shirakawa ◽  
T. Hiroshige
Keyword(s):  
Circadian Rhythm ◽  
Litter Size ◽  
Regression Line ◽  
Strong Positive Correlation ◽  
Locomotor Rhythm ◽  
Phase Reversal ◽  
Nursing Mother ◽  
Large N ◽  
Group A ◽  
Phase Setting

Postnatal phase setting of pup circadian rhythm by nursing mother was examined in rats by mother-pup exchange experiments. To know the effect of phase reversal of the nursing mother, pups were exchanged after birth so that a mother rat raised pups, half of which were born to her and the other half which came from a reversed mother, and activity onset and offset of pup locomotor rhythm were measured at weaning. Effects of litter size were also examined. Direct entrainment to light-dark cycles was excluded by blinding pups. In the unexchanged group, a strong positive correlation was detected between the phase of the circadian rhythm at weaning and the free-running period measured after weaning. The area covered by the 99% confidence interval of the regression line was used for the phase reference zone, and the circadian rhythm of an exchanged pup whose phase at weaning was located outside the reference zone was regarded as having been influenced by the nursing mother. The complete phase reversal occurred in two out of seven exchanged pups when litter size was relatively large (n = 5-7) and in 9 out of 11 when litter size was small (n = 2). It is concluded that the nursing mother rat is capable of phase setting the circadian locomotor rhythm of blinded pups. This maternal effect seems to be related to litter size.

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.

Circadian rhythms of rabbits during restrictive feeding

1987 ◽  
Vol 253 (1) ◽  
pp. R46-R54 ◽  
Author(s):  
B. Jilge ◽  
H. Hornicke ◽  
H. Stahle
Keyword(s):  
Circadian Rhythm ◽  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Food Access ◽  
Feeding Time ◽  
Restricted Feeding ◽  
Small Component ◽  
Physiological Functions ◽  
System A ◽  
Free Running

Without a zeitgeber the circadian rhythms of five physiological functions free-ran with a period length greater than 24 h. Restricted feeding time (RF) masked the free-running rhythms. In addition to masking, entrainment with RF occurred. This process was most evident in locomotor activity and visits to the food box. RF thus had zeitgeber properties in these rabbits. However, in most rabbits the RF zeitgeber was not strong enough to entrain the circadian rhythm completely. A small component free-ran during RF. Following return to continuous food access the whole circadian rhythm resumed to free-run again. In some animals its phase was determined by the RF zeitgeber and in others by the small free-running fraction present during RF. The results suggest that in addition to the light-dark-entrainable circadian oscillator system a feeding-entrainable oscillator exists that takes over phase control of the majority of the rhythm during RF.

Effect of D2O on the Circadian Rhythm of Petal Movement of Kalanchoe

1974 ◽  
Vol 29 (1-2) ◽  
pp. 36-38 ◽  
Author(s):  
Albrecht Maurer ◽  
Wolfgang Engelmann
Keyword(s):  
Circadian Rhythm ◽  
Heavy Water ◽  
Phase Shifts ◽  
Circadian Cycle ◽  
Free Running ◽  
Free Running Period

Abstract D2O lengthens the free running period of the circadian petal movement of isolated Kalanchoe flowers by 1.6% per 10% heavy water. This corresponds to findings reported in the literature for other organisms. 100% D2O administered in the form of 4 hour pulses at various phases of the circadian cycle lead to phase responses zero to maximally 1.5 hour delays. No advancing phase shifts occur. Possible ways in which lengthening of the period occurs are discussed.

scholarly journals A circadian clock in a nonphotosynthetic prokaryote

2021 ◽  
Vol 7 (2) ◽  
pp. eabe2086
Author(s):  
Zheng Eelderink-Chen ◽  
Jasper Bosman ◽  
Francesca Sartor ◽  
Antony N. Dodd ◽  
Ákos T. Kovács ◽  
...  
Keyword(s):  
Temperature Compensation ◽  
Temporal Structure ◽  
Bacterial Biofilm ◽  
Circadian Clocks ◽  
Industrial Processes ◽  
Free Living ◽  
Considerable Potential ◽  
Free Running ◽  
Free Running Period ◽  
Constant Dark

Circadian clocks create a 24-hour temporal structure, which allows organisms to occupy a niche formed by time rather than space. They are pervasive throughout nature, yet they remain unexpectedly unexplored and uncharacterized in nonphotosynthetic bacteria. Here, we identify in Bacillus subtilis circadian rhythms sharing the canonical properties of circadian clocks: free-running period, entrainment, and temperature compensation. We show that gene expression in B. subtilis can be synchronized in 24-hour light or temperature cycles and exhibit phase-specific characteristics of entrainment. Upon release to constant dark and temperature conditions, bacterial biofilm populations have temperature-compensated free-running oscillations with a period close to 24 hours. Our work opens the field of circadian clocks in the free-living, nonphotosynthetic prokaryotes, bringing considerable potential for impact upon biomedicine, ecology, and industrial processes.

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