The effect of light on the human circadian pacemaker.
The effect of light on the human circadian pacemaker.
复制标题
光对人体昼夜节律起搏器的影响。
DOI：
10.1002/9780470514597.ch14
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Czeisler,CA
中科院分区：
文献类型：
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作者：
Czeisler,CA
周期性的明暗周期提供了使人类昼夜节律起搏器与一天 24 小时同步的主要信号。早期的报道称，在控制人类昼夜节律方面，社交接触比光更有效，但最近的研究并未支持这一点。事实上，我们发现暴露于周期性光刺激可以引起人类昼夜节律起搏器的强烈（0型）重置，这表明暴露于光会影响起搏器的振荡幅度及其相位。这些发现支持了 Winfree 长期以来的预测，基于他对生物钟分析中振幅重要性的开创性认识，强（0 型）重置将被证明是从藻类到人类等多种物种对光的昼夜节律重置反应的共同属性。对人类的研究首次表明，昼夜节律起搏器对光的反应不仅取决于光照的时间、强度和持续时间，还取决于每天连续光照的次数。在关键阶段暴露于临界强度的光甚至可以将人类昼夜节律起搏器驱动到奇点区域，类似于暂时“停止”人类生物钟。这些发现对于昼夜节律睡眠障碍的治疗具有重要意义，因为正确定时的光照可以在一到三天内将人体时钟重置为任何所需的时间。
The periodic light–dark cycle provides the primary signal by which the human circadian pacemaker is synchronized to the 24 h day. Earlier reports that social contacts were more effective than light in the entrainment of human circadian rhythms have not been supported by more recent studies. In fact, we have found that exposure to a cyclic light stimulus can induce strong (type 0) resetting of the human circadian pacemaker, indicating that exposure to light affects the pacemaker's amplitude of oscillation as well as its phase. These findings support Winfree's long‐standing prediction, based on his pioneering recognition of the importance of amplitude in the analysis of circadian clocks, that strong (type 0) resetting would prove to be a common property of circadian resetting responses to light across a wide array of species, from algae to humans. Research on humans has shown, for the first time, that the response of the circadian pacemaker to light depends not only on the timing, intensity and duration of light exposure, but also on the number of consecutive daily light exposures. Exposure to light of a critical strength at a critical phase can even drive the human circadian pacemaker to its region of singularity, akin to temporarily ‘stopping’ the human circadian clock. These findings have important implications for the treatment of circadian rhythm sleep disorders, because properly timed exposure to light can reset the human clock to any desired hour within one to three days.