Effect of Light/Dark Cycle on Wheel Running and Responding Reinforced by the Opportunity to Run Depends on Postsession Feeding Time

2008 ◽  
Vol 58 (3) ◽  
pp. 391-404 ◽  
Author(s):  
T. W. Belke ◽  
A. R. Mandrona ◽  
K. M. Conrad ◽  
K. F. Poirier ◽  
K. L. Pickering
Keyword(s):  
Wheel Running ◽  
Feeding Time ◽  
Dark Cycle ◽  
Effect Of Light

Adrenal corticoids in hamsters: role in circadian timing

1985 ◽  
Vol 248 (4) ◽  
pp. R434-R438 ◽  
Author(s):  
H. E. Albers ◽  
L. Yogev ◽  
R. B. Todd ◽  
B. D. Goldman
Keyword(s):  
Wheel Running ◽  
Sampling Period ◽  
Dark Phase ◽  
Cortisol Secretion ◽  
Experimental Protocol ◽  
Light Phase ◽  
Dark Cycle ◽  
Physiological Control ◽  
Circadian Organization

The 24-h patterns of circulating cortisol and corticosterone were determined in male hamsters housed under a 14:10 light-dark cycle. Corticoid levels varied significantly over the 24-h sampling period with peak levels of both hormones occurring near the onset of the daily dark phase. The ratio of cortisol to corticosterone changed dramatically during the day. Corticosterone levels were significantly higher than cortisol during the early part of the light phase; however, cortisol levels became significantly higher than corticosterone when both hormones began their daily rise. To examine whether the circadian rhythm of cortisol secretion could be involved in the physiological control of hamster circadian organization, cortisol was infused at approximately physiological levels into adrenalectomized hamsters either continuously or in a 24-h rhythm. No significant differences were observed in the timing of circadian wheel-running rhythms in hamsters housed in LD 16:8, LD 14:10, or LL when cortisol was infused continuously, in a 24-h rhythm that mimicked the cortisol rhythm of intact hamsters, or in a 24-h rhythm several hours out of phase with the rhythm of intact hamsters. Provision of cortisol in a 24-h rhythm appeared to promote the survival of adrenalectomized hamsters since hamsters receiving a 24-h pattern of cortisol survived the experimental protocol significantly longer than those receiving the same dose of cortisol continuously.

scholarly journals Diel feeding pattern and diet of rough scad Trachurus lathami Nichols, 1920 (Carangidae) from the Southwestern Atlantic

2006 ◽  
Vol 4 (4) ◽  
pp. 419-426 ◽  
Author(s):  
Maria Raquel de Carvalho ◽  
Lucy Satiko Hashimoto Soares
Keyword(s):  
Feeding Activity ◽  
Stomach Contents ◽  
Feeding Time ◽  
Frequency Of Occurrence ◽  
Southwestern Atlantic ◽  
Calanoid Copepods ◽  
Teleostean Fish ◽  
Dark Cycle ◽  
Percent Number ◽  
Decapod Larvae

Diel changes in feeding activity and dietary composition of the rough scad Trachurus lathami were investigated through the analysis of stomach contents of 307 fish sampled over a 24-h period on the continental shelf off Ubatuba (23º 35'S 45ºW). Stomach contents were analyzed by frequency of occurrence (O%), percent number (N%), percent mass (M%), and feeding index (FI% = O% * M%). Rough scad fed on mollusks (Gastropoda, Crepidula sp.), crustacean (Ostracoda, Copepoda, decapod larvae), chaetognat and teleostean fish. The main items were calanoid copepods (Eucalanus sp. and Centropages sp.). According to the analysis of the stomach fullness and prey digestion, T. lathami is both a diurnal and nocturnal feeder, showing some seasonal variation in feeding time. According to the Chronobiology concept, it was raised the hypothesis of circadian rhythm in feeding of this fish, probably synchronized by light/dark cycle.

Light-dark cycle and feeding time differentially entrains the gut molecular clock of the goldfish (Carassius auratus).

2012 ◽  
Vol 29 (6) ◽  
pp. 665-673 ◽  
Author(s):  
Laura G. Nisembaum ◽  
Elena Velarde ◽  
Ana B. Tinoco ◽  
Clara Azpeleta ◽  
Nuria de Pedro ◽  
...  
Keyword(s):  
Molecular Clock ◽  
Carassius Auratus ◽  
Feeding Time ◽  
Dark Cycle ◽  
Goldfish Carassius Auratus

scholarly journals Effect of light/dark cycle on nitrate and phosphate removal from synthetic wastewater based on BG11 medium by Scenedesmus sp.

3 Biotech ◽  
2019 ◽  
Vol 9 (4) ◽  
Author(s):  
Adnan Habibi ◽  
Ghorban Ali Nematzadeh ◽  
Farshid Pajoum shariati ◽  
Hossein Delavari Amrei ◽  
Abolghasem Teymouri
Keyword(s):  
Phosphate Removal ◽  
Synthetic Wastewater ◽  
Dark Cycle ◽  
Bg11 Medium ◽  
Effect Of Light

Activity rhythm of golden hamster (Mesocricetus auratus) can be entrained to a 19-h light-dark cycle

2005 ◽  
Vol 289 (4) ◽  
pp. R998-R1005 ◽  
Author(s):  
Juan J. Chiesa ◽  
Montserrat Anglès-Pujolràs ◽  
Antoni Díez-Noguera ◽  
Trinitat Cambras
Keyword(s):  
Golden Hamster ◽  
Wheel Running ◽  
Activity Rhythm ◽  
Mesocricetus Auratus ◽  
Precise Determination ◽  
Dark Cycle ◽  
Running Wheel ◽  
Running Activity ◽  
Wheel Running Activity

Both temporary access to a running wheel and temporary exposure to light systematically influence the phase producing entrainment of the circadian activity rhythm in the golden hamster ( Mesocricetus auratus). However, precise determination of entrainment limits remains methodologically difficult, because such calculations may be influenced by varying experimental paradigms. In this study, effects on the entrainment of the activity pattern during successive light-dark (LD) cycles of stepwise decreasing periods, as well as wheel running activity, were investigated. In particular, the hamster activity rhythm under LD cycles with a period (T) shorter than 22 h was studied, i.e., when the LD cycle itself had been shown to be an insufficiently strong zeitgeber to synchronize activity rhythms. Indeed, it was confirmed that animals without a wheel do not entrain under 11:11-h LD cycles (T = 22 h). Subsequently providing hamsters continuous access to a running wheel established entrainment to T = 22 h. Moreover, this paradigm underwent further reductions of the T period to T = 19.6 h without loss of entrainment. Furthermore, restricting access to the wheel did not result in loss of entrainment, while even entrainment to T = 19 h was observed. To explain this observed shift in the lower entrainment limit, our speculation centers on changes in pacemaker response facilitated by stepwise changes of T spaced very far apart, thus allowing time for adaptation.

Sex differences in the circadian control of hamster wheel-running activity

1983 ◽  
Vol 244 (1) ◽  
pp. R93-R105 ◽  
Author(s):  
F. C. Davis ◽  
J. M. Darrow ◽  
M. Menaker
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Wheel Running ◽  
Phase Shifts ◽  
Light Cycle ◽  
Dark Cycle ◽  
Running Activity ◽  
Wheel Running Activity ◽  
Activity Onset ◽  
Males And Females

The circadian pacemaker that underlies the wheel-running activity of hamsters was studied in males and females. Sex differences were found in the mechanism by which the pacemaker entrains to light-dark cycles and in the timing of activity onset. When exposed to a light-dark cycle with a period of 24.75 h (with 1 h of light/cycle), males show a greater ability to maintain entrainment than do females. This difference in the upper limit of entrainment appears due to a sex difference in the magnitude of light-induced phase shifts. A small difference in free-running period may also contribute to the sex difference in entrainment. Two weeks after castration of adults, the sex difference in entrainment is not affected, indicating that the difference does not depend on circulating gonadal steroids or on estrous cyclicity of the female. However, castration of females at an early age increases their ability to entrain, whereas long-term castration of males seems to reduce entrainment ability. During entrainment to a 24-h light-dark cycle (LD 14:10), females were found to begin their daily activity before males and before castrated females. This difference is consistent with a sex difference in the magnitude of light-induced phase shifts and in entrainment of the pacemaker. However, evidence is given that the sex difference in activity onset might also be caused by a sex difference in the relationship of locomotor activity to the pacemaker in intact males and females.

scholarly journals CIRCADIAN PATTERNS OF FREE-WHEEL RUNNING IN YOUNG AND OLD MICE

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S911-S911
Author(s):  
Carly Hibbs ◽  
Musharraf Yusifova ◽  
Benjamin McNair ◽  
Danielle Bruns ◽  
Emily Schmitt
Keyword(s):  
Wheel Running ◽  
Delayed Response ◽  
Dark Phase ◽  
Peak Activity ◽  
Dark Cycle ◽  
Circadian Misalignment ◽  
Peripheral Muscle ◽  
The Impact ◽  
Old Mice ◽  
Young Mice

Abstract The mammalian circadian clock operates on a 24-hour cycle and regulates physiological, endocrine, and metabolic responses to changes in the environment. Aging disrupts this circadian process, increasing risk for development of age-associated diseases. Free-wheel running is not only an indicator of circadian rhythm, but also a strong predictor of survival from age-related diseases (i.e. cardiovascular disease). Thus, understanding the impact of age on free-wheel running can lead to a better understanding of disease progression. We analyzed free wheel running in both male and female C57BL/6J mice at young (3-6 months) and old (18-21 months) ages exposed to standard 12h light/dark cycle. Running wheel data was recorded hourly for 10 days. As expected, young female mice ran more than male mice, and old mice ran less than young mice. Regulation of wheel running demonstrated that older mice of both sexes had a delayed start time in activity patterns. Young mice began running immediately at lights off (signaling the start of their active period) and ran consistently throughout the dark phase with peak activity in the first 2 hours. In contrast, older mice had a delayed response to light with peak activity not occurring until hours 4-6 of the dark cycle and nightly activity ending 2 hours before lights on. Ongoing work will assess the central (brain) and peripheral (muscle, cardiac) regulation of free-wheel running in aging. Together, we demonstrate the importance of studying molecular mechanisms underlying circadian misalignment in older individuals to identify ways to combat age-associated disease with circadian misalignment.

scholarly journals SCN lesions abolish ultradian and circadian components of activity rhythms in LEW/Ztm rats

1989 ◽  
Vol 256 (5) ◽  
pp. R1027-R1039 ◽  
Author(s):  
F. Wollnik ◽  
F. W. Turek
Keyword(s):  
Activity Pattern ◽  
Wheel Running ◽  
Dark Cycle ◽  
Spectral Estimates ◽  
Running Activity ◽  
Wheel Running Activity ◽  
Neural Substrate ◽  
Free Running ◽  
Males And Females ◽  
Periodogram Analysis

A trimodal locomotor activity pattern has been observed in LEW/Ztm rats. Complete and partial lesions of the suprachiasmatic nucleus (SCN) were used to determine whether the same neural substrate may underlie the circadian rhythms and the ultradian modulation of wheel-running activity in these rats. Whereas sham lesions had little or no effect on the wheel-running activity pattern, complete SCN lesions resulted in a complete loss of circadian and ultradian activity components under free-running or 12:12 h light-dark cycle (12:12 LD) conditions. Ultradian and circadian activity components were still present after partial SCN lesions. Periodogram analysis for any given animal revealed that the ultradian periods were always submultiples of the entrained or free-running circadian period. Furthermore there was a high correlation between the amplitudes of circadian and ultradian spectral estimates, but with a different slope in males and females. These results indicate that in LEW/Ztm rats the SCN contributes to the control of both the circadian wheel-running rhythm and the trimodal ultradian modulation of that behavior.

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