昼夜节律是指生命活动以24小时为周期的内在性节律。为了适应昼夜环境周期性的变化,地球上几乎所有生物体,包括藻类、细菌、植物、动物等,都演化出一个特殊的系统——生物钟,用以指挥不同组织与器官来适应环境的昼夜交替,维持机体的生理稳态和行为与环境昼夜变化同步。生物钟是指由内源性分子时钟控制的日周生理振荡过程,人类生命活动的各个层面,包括行为、生理、代谢等都受到生物钟的调控,并表现出明显的昼夜节律,如睡眠与苏醒、警觉程度与运动能力、体温波动、泌尿系统、激素分泌、免疫调节以及细胞因子释放等。昼夜节律紊乱可能影响各种疾病的发生、发展、治疗和预后。因此在机体的发育、衰老及疾病的发生、发展过程中评估昼夜节律是否异常具有重要的意义。结合本课题组相关研究,本文较为系统性地讨论了几种适用不同目的鉴别昼夜节律行为异常的方法,分享了具体的实验操作以及分析思路,包括利用代谢笼测量活动节律、自由跑轮活动监测、倒时差、长光照、骨骼光周期以及T7-cycle,并解释了不同行为学方法背后的生理意义。除此之外,本文还探究了不同遗传背景以及不同来源小鼠的昼夜节律在适应外界环境变化上的可能差异,为相关研究提供了可行的参考。根据这些原则及方法,以期帮助相关科研人员选择合适的实验来评估遗传因素、环境因素或疾病对昼夜节律行为的影响。

Circadian rhythms have a cycle length of about 24 hours, i.e. a 24-hour internal clock. In order to adapt to the periodic changes of the circadian environment, almost all organisms on the earth, including algae, bacteria, plants, animals, etc., have evolved a special system—the circadian clock. It helps organisms to adapt to the daily changes in the environment and maintains the physiological process and the behavior in synchronization with the environment changes. Circadian rhythms are composed of an intracellular feedback loop that drives the expression of molecular components and their constitutive protein products to oscillate over a period of about 24 hours. Almost every aspect of the body's functions, including behavior and physiology, is regulated by the circadian clock, and shows obvious daily rhythms, such as sleep and wakefulness, alertness, body temperature fluctuations, urinary system, hormone secretion, immune regulation, and cytokine release. Circadian factors are also increasingly recognized for potentially affecting the occurrence, progression, treatment, and prognosis of a variety of diseases. This paper discusses several methods for measuring circadian behavior disorders in mice for different purposes, and shares experimental operations and analysis ideas, including the use of metabolism cage, wheel running activity, jet lag, lengthened light, bones photoperiod, as well as the T7-cycle. In addition, this paper also studies the possible reasons for variations caused by genetic backgrounds and light conditions. Given these methods, researchers can choose appropriate experiments to evaluate the influence of genetic factors, environmental factors or diseases on circadian behavior.