Rimmer D W, Boivin D B, Shanahan T L, Kronauer R E, Duffy J F, Czeisler C A
Circadian, Neuroendocrine and Sleep Disorders Section, Division of Endocrinology, Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Massachussets, Boston 02115, USA.
Am J Physiol Regul Integr Comp Physiol. 2000 Nov;279(5):R1574-9. doi: 10.1152/ajpregu.2000.279.5.R1574.
In humans, experimental studies of circadian resetting typically have been limited to lengthy episodes of exposure to continuous bright light. To evaluate the time course of the human endogenous circadian pacemaker's resetting response to brief episodes of intermittent bright light, we studied 16 subjects assigned to one of two intermittent lighting conditions in which the subjects were presented with intermittent episodes of bright-light exposure at 25- or 90-min intervals. The effective duration of bright-light exposure was 31% or 63% compared with a continuous 5-h bright-light stimulus. Exposure to intermittent bright light elicited almost as great a resetting response compared with 5 h of continuous bright light. We conclude that exposure to intermittent bright light produces robust phase shifts of the endogenous circadian pacemaker. Furthermore, these results demonstrate that humans, like other species, exhibit an enhanced sensitivity to the initial minutes of bright-light exposure.
在人类中，昼夜节律重置的实验研究通常局限于长时间暴露在持续强光下。为了评估人类内源性昼夜节律起搏器对短暂间歇性强光发作的重置反应的时间进程，我们研究了16名受试者，他们被分配到两种间歇性光照条件之一，在这两种条件下，受试者分别以25分钟或90分钟的间隔接受间歇性强光暴露。与持续5小时的强光刺激相比，强光暴露的有效持续时间为31%或63%。与5小时的持续强光相比，暴露于间歇性强光引起的重置反应几乎一样大。我们得出结论，暴露于间歇性强光会使内源性昼夜节律起搏器产生强烈的相位偏移。此外，这些结果表明，人类与其他物种一样，对强光暴露的最初几分钟表现出更高的敏感性。
