Title: Strain differences of the mouse's free-running circadian rhythm in continuous darkness☆
Abstract: The circadian rhythms for 80 days of continuous darkness (DD) were examined after they were released from a LD 12:12 photoperiod. Two inbred strains of mice, DDK and C57BL/10Sn, were selected on the basis of the results of the preliminary study. The rhythms of DDK strain were unstable, while those of C57BL/10Sn were stable over 80 days of DD. In DDK strain, two patterns of rhythm were observed during the experimental period. One was characterized by larger amount of activity, clear onsets of activity, and distinct difference between activity and rest time. The other exhibited the opposite characteristics that included smaller amount of activity, blurred onsets and ends of activity, and expanded activity time. Moreover, the circadian period of the rhythm which showed clear onsets of activity was undoubtedly shorter than the other one within the same individual. In the rhythms of C57BL/10Sn, on the other hand, the features of clear onsets, larger amount of activity, distinct difference between activity and rest time were observed throughout the experimental period. These results suggest that one basic factor which affects the circadian rhythm is genetic.
Publication Year: 1978
Publication Date: 1978-06-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 62
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot