Complex circadian regulation of pineal melatonin and wheel-running in Syrian hamsters

1994 ◽  
Vol 174 (4) ◽  
Author(s):  
J.A. Elliott ◽  
L. Tamarkin
Keyword(s):  
Wheel Running ◽  
Circadian Regulation ◽  
Syrian Hamsters ◽  
Pineal Melatonin

Pineal Melatonin in Syrian Hamsters: Circadian and Seasonal Rhythms in Animals Maintained under Laboratory and Natural Conditions

1982 ◽  
Vol 35 (5) ◽  
pp. 342-348 ◽  
Author(s):  
George C. Brainard ◽  
Larry J. Petterborg ◽  
Bruce A. Richardson ◽  
Russel J. Reiter
Keyword(s):  
Natural Conditions ◽  
Seasonal Rhythms ◽  
Syrian Hamsters ◽  
Pineal Melatonin

Uncoupling of the pineal melatonin synthesis of rats from the circadian regulation

1994 ◽  
Vol 179 (1-2) ◽  
pp. 5-8 ◽  
Author(s):  
Maija-Liisa Laakso ◽  
Taina Hätönen ◽  
Aino Alila
Keyword(s):  
Circadian Regulation ◽  
Pineal Melatonin ◽  
Melatonin Synthesis

scholarly journals Impact of wheel running on chronic ethanol intake in aged Syrian hamsters

2012 ◽  
Vol 107 (3) ◽  
pp. 418-423 ◽  
Author(s):  
Allison J. Brager ◽  
Steven B. Hammer
Keyword(s):  
Wheel Running ◽  
Ethanol Intake ◽  
Chronic Ethanol ◽  
Syrian Hamsters

Photoperiod differentially modulates photic and nonphotic phase response curves of hamsters

2004 ◽  
Vol 286 (3) ◽  
pp. R539-R546 ◽  
Author(s):  
J. A. Evans ◽  
J. A. Elliott ◽  
M. R. Gorman
Keyword(s):  
Wheel Running ◽  
Phase Response Curve ◽  
Phase Shifts ◽  
Phase Response ◽  
Cycle Phase ◽  
Phase Resetting ◽  
Response Curves ◽  
Syrian Hamsters ◽  
Light Pulses ◽  
Circadian Time

Circadian pacemakers respond to light pulses with phase adjustments that allow for daily synchronization to 24-h light-dark cycles. In Syrian hamsters, Mesocricetus auratus, light-induced phase shifts are larger after entrainment to short daylengths (e.g., 10 h light:14 h dark) vs. long daylengths (e.g., 14 h light:10 h dark). The present study assessed whether photoperiodic modulation of phase resetting magnitude extends to nonphotic perturbations of the circadian rhythm and, if so, whether the relationship parallels that of photic responses. Male Syrian hamsters, entrained for 31 days to either short or long daylengths, were transferred to novel wheel running cages for 2 h at times spanning the entire circadian cycle. Phase shifts induced by this stimulus varied with the circadian time of exposure, but the amplitude of the resulting phase response curve was not markedly influenced by photoperiod. Previously reported photoperiodic effects on photic phase resetting were verified under the current paradigm using 15-min light pulses. Photoperiodic modulation of phase resetting magnitude is input specific and may reflect alterations in the transmission of photic stimuli.

Circadian Regulation of Bird Song, Call, and Locomotor Behavior by Pineal Melatonin in the Zebra Finch

2012 ◽  
Vol 27 (2) ◽  
pp. 145-155 ◽  
Author(s):  
Gang Wang ◽  
Clifford E. Harpole ◽  
Amit K. Trivedi ◽  
Vincent M. Cassone
Keyword(s):  
Zebra Finch ◽  
Bird Song ◽  
Locomotor Behavior ◽  
Circadian Regulation ◽  
Pineal Melatonin

Stability of circadian timing with age in Syrian hamsters

1998 ◽  
Vol 275 (4) ◽  
pp. R960-R968 ◽  
Author(s):  
Fred C. Davis ◽  
N. Viswanathan
Keyword(s):  
Wheel Running ◽  
Activity Level ◽  
Circadian Pacemaker ◽  
Experimental Conditions ◽  
Syrian Hamsters ◽  
Running Activity ◽  
Age Related ◽  
Wheel Running Activity ◽  
Free Running ◽  
Free Running Period

The causes of age-related disruptions in the timing of human sleep and wakefulness are not known but may include changes in both the homeostatic and circadian regulation of sleep. In Syrian hamsters the free running period of the circadian activity/rest rhythm has been reported to shorten with age. Although this has been observed under a variety of experimental conditions, the changes have been small and their consistency uncertain. In the present study, the wheel running activity/rest rhythm was continuously measured in male Syrian hamsters ( Mesocricetus auratus) in dim constant light (<1 lx) from 8 wk of age until death. Fifteen hamsters survived to at least 90 wk (28%). The average free running period of these hamsters did not change with age. In 18 hamsters that died between 50 and 88 wk, free running period also did not change before death. In contrast to free running period, other measures related to activity level changed significantly with age and before death. Despite changes in the expression of the activity/rest rhythm, the free running period of the hamster circadian pacemaker remained remarkably stable with age.

scholarly journals Pineal melatonin is a circadian time-giver for leptin rhythm in Syrian hamsters

2015 ◽  
Vol 9 ◽  
Author(s):  
Ibtissam Chakir ◽  
Stéphanie Dumont ◽  
Paul Pévet ◽  
Ali Ouarour ◽  
Etienne Challet ◽  
...  
Keyword(s):  
Syrian Hamsters ◽  
Pineal Melatonin ◽  
Circadian Time

Tetrodotoxin blocks NPY-induced but not muscimol-induced phase advances of wheel-running activity in Syrian hamsters

1997 ◽  
Vol 772 (1-2) ◽  
pp. 176-180 ◽  
Author(s):  
K.L Huhman ◽  
C.L Marvel ◽  
C.F Gillespie ◽  
E.M Mintz ◽  
H.E Albers
Keyword(s):  
Wheel Running ◽  
Syrian Hamsters ◽  
Running Activity ◽  
Wheel Running Activity

Behavioral characterization and modulation of circadian rhythms by light and melatonin in C3H/HeN mice homozygous for the RORβ knockout

2007 ◽  
Vol 292 (6) ◽  
pp. R2357-R2367 ◽  
Author(s):  
Monica I. Masana ◽  
Isabel C. Sumaya ◽  
Michael Becker-Andre ◽  
Margarita L. Dubocovich
Keyword(s):  
Circadian Rhythms ◽  
Light Pulse ◽  
Learned Helplessness ◽  
Wheel Running ◽  
Receptor Gene ◽  
Activity Rhythms ◽  
Pineal Melatonin ◽  
Running Activity ◽  
Melatonin Administration ◽  
Wheel Running Activity

This study reports for the first time the effects of retinoid-related orphan receptors [RORβ; receptor gene deletion RORβ(C3H)−/−] in C3H/HeN mice on behavioral and circadian phenotypes. Pineal melatonin levels showed a robust diurnal rhythm with high levels at night in wild-type (+/+), heterozygous (+/−), and knockout (−/−) mice. The RORβ(C3H)−/− mice displayed motor (“duck gait,” hind paw clasping reflex) and olfactory deficits, and reduced anxiety and learned helplessness-related behaviors. Circadian rhythms of wheel-running activity in all genotypes showed entrainment to the light-dark (LD) cycle, and free running in constant dark, with RORβ(C3H)−/− mice showing a significant increase in circadian period ( tau). Melatonin administration (90 μg/mouse sc for 3 days) at circadian time (CT) 10 induced phase advances, while exposure to a light pulse (300 lux) at CT 14 induced phase delays of circadian activity rhythms of the same magnitude in all genotypes. In RORβ(C3H)−/− mice a light pulse at CT 22 elicited a larger phase advance in activity rhythms and a slower rate of reentrainment after a 6-h advance in the LD cycle compared with (+/+) mice. Yet, the rate of reentrainment was significantly advanced by melatonin administration at the new dark onset in both (+/+) and (−/−) mice. We conclude that the RORβ nuclear receptor is not involved in either the rhythmic production of pineal melatonin or in mediating phase shifts of circadian rhythms by melatonin, but it may regulate clock responses to photic stimuli at certain time domains.

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