Vitaterna M H, Takahashi J S, Turek F W
Center for Functional Genomics, Northwestern University, Evanston, Illinois, USA.
Alcohol Res Health. 2001;25(2):85-93.
The daily light-dark cycle governs rhythmic changes in the behavior and/or physiology of most species. Studies have found that these changes are governed by a biological clock, which in mammals is located in two brain areas called the suprachiasmatic nuclei. The circadian cycles established by this clock occur throughout nature and have a period of approximately 24 hours. In addition, these circadian cycles can be synchronized to external time signals but also can persist in the absence of such signals. Studies have found that the internal clock consists of an array of genes and the protein products they encode, which regulate various physiological processes throughout the body. Disruptions of the biological rhythms can impair the health and well-being of the organism.
昼夜明暗循环控制着大多数物种行为和/或生理的节律性变化。研究发现,这些变化受生物钟调控,在哺乳动物中,生物钟位于两个称为视交叉上核的脑区。由这个生物钟建立的昼夜节律在自然界中普遍存在,周期约为24小时。此外,这些昼夜节律可以与外部时间信号同步,但在没有此类信号的情况下也能持续存在。研究发现,内部生物钟由一系列基因及其编码的蛋白质产物组成,它们调节着全身的各种生理过程。生物节律的紊乱会损害生物体的健康和福祉。