摘要：The spontaneous circadian motor activity of first generation (F 1 ) hybrid male C57BL/6×C3H mice irradiated with gamma rays on the 14th day of gestation was studied at the following ages : young (6-7 months), adult (12-13 months), and old (19-20 months). Doses were 0.1, 0.2, 0.5 or 1.0 Gy. A 12-hour day-night cycle was maintained with light on at 6:00 hr. Spontaneous circadian motor activity was recorded with a capacitance-induction motility monitor for 48 consecutive hours. Activity was measured at 2-hour intervals, and the data stored on computer discs. The activity of the 1.0 Gy group recorded at 22:00 and 2:00 hr for young mice and at 2:00 hr for adult ones was significantly higher than that of the age-matched control group. Results suggest that male mice irradiated with 1.0 Gy at gestational day 14 show nocturnal hyperactivity in the young and adult stages.
