Formal properties of the circadian system underlying photoperiodic time-measurement in Japanese quail

1982 ◽  
Vol 145 (3) ◽  
pp. 381-390 ◽  
Author(s):  
S. M. Simpson ◽  
B. K. Follett
Keyword(s):  
Japanese Quail ◽  
Time Measurement ◽  
Circadian System ◽  
Formal Properties

Eye and gonad: role in the dual-oscillator circadian system of female Japanese quail

1997 ◽  
Vol 272 (1) ◽  
pp. R172-R182 ◽  
Author(s):  
H. Underwood ◽  
T. Siopes ◽  
K. Edmonds
Keyword(s):  
Body Temperature ◽  
Japanese Quail ◽  
Time Measurement ◽  
Circadian System ◽  
Light Perception ◽  
Physiological Basis ◽  
Temperature Rhythm ◽  
Body Temperature Rhythm ◽  
Free Running ◽  
Phase Relationships

Experiments were conducted to determine the anatomic and physiological basis of the dual-oscillator circadian system of female Japanese quail. After blocking of ocular light perception by eye-patching, the circadian body temperature rhythm dissociates into two circadian components in continuous lighting (LL). One component free runs with a period significantly shorter than 24 h [mean period (tau) = 22.7 h] and is driven by an ocular pacemaker, whereas the other component free runs with a period significantly longer than 24 h (tau = 26.3 h). The long free-running rhythm is driven by the same circadian clock that drives the circadian rhythm of ovulation. The expression of the long free-running rhythm in LL depends on the presence of the ovary: body temperature rhythmicity is abolished by ovariectomy. The two free-running oscillators in eye-patched birds showed evidence of mutual interaction. Significantly, the phase relationships that occur as the two oscillators interact can determine whether or not ovulation occurs. The results are discussed in terms of an "internal coincidence" mechanism for photoperiodic time measurement.

The Role of the Circadian System in Photoperiodic Time Measurement in Mammals

1995 ◽  
pp. 95-105 ◽  
Author(s):  
Michael H. Hastings ◽  
Elizabeth S. Maywood ◽  
Francis J. P. Ebling
Keyword(s):  
Time Measurement ◽  
Circadian System

scholarly journals Circadian molecular clocks tick along ontogenesis

2008 ◽  
pp. S139-S148
Author(s):  
A Sumová ◽  
Z Bendová ◽  
M Sládek ◽  
R El-Hennamy ◽  
K Matějů ◽  
...  
Keyword(s):  
Current Model ◽  
Complex Structure ◽  
Postnatal Period ◽  
Circadian System ◽  
Molecular Clocks ◽  
Suprachiasmatic Nuclei ◽  
Intercellular Coupling ◽  
Peripheral Clocks ◽  
Complete Set ◽  
Formal Properties

The circadian system controls the timing of behavioral and physiological functions in most organisms studied. The review addresses the question of when and how the molecular clockwork underlying circadian oscillations within the central circadian clock in the suprachiasmatic nuclei of the hypothalamus (SCN) and the peripheral circadian clocks develops during ontogenesis. The current model of the molecular clockwork is summarized. The central SCN clock is viewed as a complex structure composed of a web of mutually synchronized individual oscillators. The importance of development of both the intracellular molecular clockwork as well as intercellular coupling for development of the formal properties of the circadian SCN clock is also highlighted. Recently, data has accumulated to demonstrate that synchronized molecular oscillations in the central and peripheral clocks develop gradually during ontogenesis and development extends into postnatal period. Synchronized molecular oscillations develop earlier in the SCN than in the peripheral clocks. A hypothesis is suggested that the immature clocks might be first driven by external entraining cues, and therefore, serve as "slave" oscillators. During ontogenesis, the clocks may gradually develop a complete set of molecular interlocked oscillations, i.e., the molecular clockwork, and become self-sustained clocks.

Molecular Mechanism of Photoperiodic Time Measurement in the Brain of Japanese Quail

2006 ◽  
Vol 23 (1-2) ◽  
pp. 307-315 ◽  
Author(s):  
Shinobu Yasuo ◽  
Miwa Watanabe ◽  
Masayuki Iigo ◽  
Takashi Yamamura ◽  
Nobuhiro Nakao ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Japanese Quail ◽  
Time Measurement ◽  
The Brain

scholarly journals Rapid Photoperiodic Responses in Japanese Quail: Is Daylength Measurement Based upon a Circadian System?

1987 ◽  
Vol 2 (2) ◽  
pp. 139-152 ◽  
Author(s):  
Monica S. Saiovici ◽  
Trevor J. Nicholls ◽  
Brian K. Follett
Keyword(s):  
Japanese Quail ◽  
Circadian System ◽  
Photoperiodic Responses

Formal Properties of the Circadian and Photoperiodic Systems of Japanese Quail: Phase Response Curve and Effects of T-Cycles

1999 ◽  
Vol 14 (5) ◽  
pp. 378-390 ◽  
Author(s):  
Bora D. Zivkovic ◽  
Herbert Underwood ◽  
Christopher T. Steele ◽  
Kent Edmonds
Keyword(s):  
Japanese Quail ◽  
Response Curve ◽  
Phase Response Curve ◽  
Phase Response ◽  
Formal Properties

Dark pulses affect the circadian rhythm of activity in hamsters kept in constant light

1982 ◽  
Vol 242 (1) ◽  
pp. R44-R50 ◽  
Author(s):  
G. B. Ellis ◽  
R. E. McKlveen ◽  
F. W. Turek
Keyword(s):  
Response Curve ◽  
Phase Response Curve ◽  
Circadian System ◽  
Constant Light ◽  
Constant Darkness ◽  
Light Pulses ◽  
Subjective Night ◽  
Free Running ◽  
Male Golden Hamsters ◽  
Formal Properties

We compared the effects of light pulses in constant darkness (DD) and dark pulses in constant light (LL) on the free-running rhythm of locomotor activity in male golden hamsters. Light pulses yielded advances, delays, or no change in the rhythm of activity. These data conform to a typical phase-response curve; this curve was unaffected by pinealectomy. Dark pulses occurring either late in the subjective night or early in the subjective day had little effect. In contrast, dark pulses occurring either late in the subjective day or early in the subjective night altered the rhythm in one of three ways: advance of the rhythm; splitting into two components; or induction of a new component, in phase with the pulse. Because dark pulses in LL perturb the circadian system in a different manner than do light pulses in DD, they may have value in identifying heretofore unknown aspects of circadian systems. As such, the use of dark pulses to perturb circadian rhythmicity will be a useful tool in examining the formal properties of circadian systems.

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