同样是熬了一个通宵，有的人会疲惫不堪，有的人却没觉得有多累。欧洲科研人员最新的研究证实，这种差异实际上和一个名为PER3的基因有关。
来自比利时和英国的研究人员在24日出版的《神经学杂志》上报告说，此前的研究就发现PER3基因与人缺觉后的反应有关，这个基因分为长版和短版两种。拥有短版PER3基因的人熬夜后认知能力仍然如常，显示对睡眠缺乏的承受有一定弹性。而拥有长版PER3基因的人对熬夜非常敏感，熬夜后大脑活动明显减少。
此次，研究人员利用大脑扫描成像技术，揭示了长版和短版PER3基因具体如何影响人对熬夜的反应。分析发现，拥有短版PER3基因的人熬夜后，在完成认知任务时，除了会激活正常的大脑区域，还会额外调动其他区域的大脑结构前来“帮忙”。而拥有长版PER3基因的人大脑则没有这么灵活。
研究人员说，有些特殊行业，比如医护人员、民航飞行员、卡车司机等，时常需夜间工作。而通过PER3基因检测，可以识别出哪些人群不适合夜间工作，从而可以个性化地安排工作。（生物谷Bioon.com）
生物谷推荐原始出处：
The Journal of Neuroscience, June 24, 2009, 29(25):7948-7956; doi:10.1523/JNEUROSCI.0229-09.2009
Functional Magnetic Resonance Imaging-Assessed Brain Responses during an Executive Task Depend on Interaction of Sleep Homeostasis, Circadian Phase, and PER3 Genotype
Gilles Vandewalle,1 Simon N. Archer,2 Catherine Wuillaume,1 Evelyne Balteau,1 Christian Degueldre,1 André Luxen,1 Pierre Maquet,1 and Derk-Jan Dijk2
1Cyclotron Research Centre, University of Liège, B-4000 Liège, Belgium, and 2Surrey Sleep Research Centre, University of Surrey, Guildford, Surrey GU2 7XP, United Kingdom
Cognition is regulated across the 24 h sleep-wake cycle by circadian rhythmicity and sleep homeostasis through unknown brain mechanisms. We investigated these mechanisms in a functional magnetic resonance imaging study of executive function using a working memory 3-back task during a normal sleep-wake cycle and during sleep loss. The study population was stratified according to homozygosity for a variable-number (4 or 5) tandem-repeat polymorphism in the coding region of the clock gene PERIOD3. This polymorphism confers vulnerability to sleep loss and circadian misalignment through its effects on sleep homeostasis. In the less-vulnerable genotype, no changes were observed in brain responses during the normal-sleep wake cycle. During sleep loss, these individuals recruited supplemental anterior frontal, temporal and subcortical regions, while executive function was maintained. In contrast, in the vulnerable genotype, activation in a posterior prefrontal area was already reduced when comparing the evening to the morning during a normal sleep-wake cycle. Furthermore, in the morning after a night of sleep loss, widespread reductions in activation in prefrontal, temporal, parietal and occipital areas were observed in this genotype. These differences occurred in the absence of genotype-dependent differences in circadian phase. The data show that dynamic changes in brain responses to an executive task evolve across the sleep-wake and circadian cycles in a regionally specific manner that is determined by a polymorphism which affects sleep homeostasis. The findings support a model of individual differences in executive control, in which the allocation of prefrontal resources is constrained by sleep pressure and circadian phase.
