[Diurnal rhythms in locomotor activity of the house musk shrew, Suncus murinus]

A diurnal rhythm of locomotor activity in male and female house musk shrews (Jic:SUN) aged approximately one year was observed under a schedule of 12 hr light and 12 hr darkness (light on at 07:00) over a period of 10 days. In general, the pattern of locomotor activity was similar in both sexes, with around 24-hr diurnal rhythm. A few typical patterns of locomotor activity in these animals were as follows: A. Locomotion interval was close in the light phase, while was sparse in the dark phase. B. As opposed to the pattern of A, locomotion interval was close in the dark and sparse in the light phases. C. Its interval remains stationary through a whole day.