Weinert D, Sitka U, Minors D S, Waterhouse J M
Department of Zoology, Martin-Luther-University, Halle, Germany.
Early Hum Dev. 1994 Feb;36(2):117-26. doi: 10.1016/0378-3782(94)90039-6.
Eleven healthy, full-term babies were studied on the second day (d2) after birth and again 4 weeks (w4) later. The babies lived in natural lighting conditions and were fed every 4 h. Blood pressure, heart rate, skin (abdomen) and rectal temperatures were measured at 10-min intervals for 24 h. Behavioural states (deep sleep, light sleep, drowsy, alert, crying) were measured at the same times, and used to purify the raw data. Both the raw and purified data were assessed for circadian (24-h) rhythmicity by cosinor analysis. Circadian rhythms in heart rate and blood pressure were poorly developed at d2 and w4. By contrast, skin and rectal temperatures showed circadian rhythmicity that increased in amplitude between d2 and w4; this increase was seen in both raw and purified data. The masking effect due to sleep changed also; the depression caused by "deep sleep" became greater between d2 and w4. The results indicate that the development of circadian rhythmicity in body temperature was not secondary to that of a circadian pattern of sleep and activity, and presumably derives from a body clock that is beginning to develop independently.
对11名健康足月婴儿在出生后第二天（d2）及4周后（w4）进行了研究。这些婴儿生活在自然光照条件下，每4小时喂食一次。每隔10分钟测量一次血压、心率、皮肤（腹部）温度和直肠温度，持续24小时。同时测量行为状态（深度睡眠、浅睡眠、困倦、警觉、哭闹），并用于净化原始数据。通过余弦分析评估原始数据和净化后的数据的昼夜（24小时）节律性。心率和血压的昼夜节律在d2和w4时发育较差。相比之下，皮肤温度和直肠温度显示出昼夜节律性，且在d2和w4之间振幅增加；原始数据和净化后的数据均出现这种增加。睡眠引起的掩盖效应也发生了变化；“深度睡眠”导致的体温降低在d2和w4之间变得更大。结果表明，体温昼夜节律性的发展并非继发于睡眠和活动的昼夜模式，可能源自一个开始独立发育的生物钟。
