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Mechanisms of action of light on circadian rhythms in the monkeyLight is considered by many investigators to be the primary Zeitgeber for most physiologic rhythms. In order to study the effects on biorhythms of changing photoperiods and to provide information on the nature of the wave forms and the mechanisms of entrainment, unrestrained male monkeys (Cebus albifrons, Macaca nemestrina) were maintained in a sound-proofed environmental chamber. The Cebus was initially maintained on a 12L:12D schedule; it was subjected to a 180 degrees phase shift for 14 days, then returned to the original photoperiod. In two experiments (24 days; 27 days each) the same monkey was again maintained on a 12L:12D schedule which was gradually altered to a constant light environment. Deep body temperature (DBT) data were obtained with miniature radiotransmitters. Locomotor activity (LMA) was measured by strain gauges. Under the 12L:12D regimens the Macaca DBT cycles were uniform as to phase and wave form for over 60 weeks. These wave forms were analyzed by the use of periodogram and correlogram analyses and by fitting to the Volterra Integro-Differential Equation. Phase angle relationships between Zeitgeber and physiologic parameters were characterized. After the photoperiod phase shift the DBT cycle rephased in about 9 days. During the rephasing process the wave form changed. The shapes of the wave forms of DBT and activity were maintained with increasing light until an 18L:6D photoperiod was reached. The rhythms were entrained to the onset of darkness rather than lights on. Major and minor periods of LMA were detected. Hysteresis diagrams showed that DBT led the onset of major LA by 6 hr and the end of major activity by 2 hr.
Document ID
20040088490
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Winget, C. M.
(NASA Ames Research Center Moffett Field CA United States)
Rosenblatt, L. S.
DeRoshia, C. W.
Hetherington, N. W.
Date Acquired
August 21, 2013
Publication Date
January 1, 1970
Publication Information
Publication: Life sciences and space research
Volume: 8
ISSN: 0075-9422
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other

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