Short light-dark cycles affect sleep in mice
Short light-dark cycles affect sleep in mice
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DOI：
10.1111/j.1460-9568.2007.05964.x
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发表时间：
2007-12-01
影响因子：
3.4
通讯作者：
Meijer, Johanna H.
中科院分区：
文献类型：
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作者：
Deboer, Tom;Ruijgrok, Guido;Meijer, Johanna H.
环境光对人类的生理和行为有很大的影响，包括认知功能和警觉性。先前的研究表明，短的明暗周期(LD)会影响白化大鼠的睡眠。快速眼动(REM)睡眠在黑暗开始后增加，在光线开始后增加。在目前的研究中，我们调查了光是否会影响小鼠的睡眠。为此，我们记录了9只成年雄性C57BL/6小鼠在12：12h基础LD条件下的脑电和肌电，然后是24 h连续黑暗(DD)和6天，按不同持续时间(2小时、30分钟、14分钟、10分钟、4分钟和2分钟)的LD循环顺序排列。NREM睡眠在所有短LD周期的明暗间隔中均匀分布。然而，在短(10-30分钟)LD周期的暗间期，REM睡眠增加。分析表明，在这些LD周期中，REM睡眠的增加在天黑开始后的第二分钟最大，其中有REM睡眠的时相的百分比显著增加到基线的175%。这一增加归因于快速眼动睡眠发作持续时间的增加。记录的反应表明，小鼠的睡眠受到光刺激的影响。结果表明，有色动物在黑暗开始后可以表现出快速眼动睡眠的诱导，这表明光照对睡眠的调节有显著的影响。
Environmental light has a strong impact on human physiology and behaviour, including cognitive functioning and alertness. Previous studies have shown that short light-dark (LD) cycles influence sleep in the albino rat. Rapid eye movement (REM) sleep increases after the onset of darkness and increases after light onset. In the present study, we investigated whether light affects sleep in mice. To this purpose the electroencephalogram and electromyogram of nine adult male C57BL/6 mice was recorded under 12 : 12 h baseline LD conditions, followed by 24 h continuous darkness (DD) and 6 days with LD cycles of different durations (2 h, 30 min, 14 min, 10 min, 4 min and 2 min), presented in a randomized order. NREM sleep was evenly distributed over the light and dark intervals of all short LD cycles. REM sleep, however, was increased during the dark intervals of short (10-30 min) LD cycles. Analysis showed that in these LD cycles, the increment in REM sleep was maximal in the second minute after dark onset, where the percentage of epochs with REM sleep increased significantly to 175% of baseline values. This increase was attributable to an increase in REM sleep episode duration. The recorded responses show that sleep in mice is affected by photic stimulation. The results demonstrate that pigmented animals can show REM sleep induction after dark onset and indicate that light has significant effects on the regulation of sleep.