Investigating the compartment-specific functions of G protein-coupled receptor kinase 2 in the central circadian clock of mice

大多数生物体拥有一种内在的计时机制，称为生物钟，它将行为和生理过程临时组织到近24小时的周期。生物钟以一种自我维持的方式振荡，但能够根据光线或其他外部时间提示重新设置其相位。这种使行为和生理与环境明暗周期同步(或引导)的能力对于生物钟的主要功能至关重要：作为外部时间的内部预报器，并在这样做的过程中促进对环境变化的适应。在哺乳动物中，中央昼夜节律起搏器位于下丘脑的视交叉上核(SCN)，它是光作用于昼夜节律系统其余部分的门户。细胞间和细胞内的通信对于SCN时钟的正常运行是必不可少的。

Most living organisms possess an intrinsic timekeeping mechanism, known as the circadian clock, that temporally organizes behavioural and physiological processes to near-24h cycles. The circadian clock oscillates in a self-sustaining fashion, but is able to reset its phase in response to light or other external time cues. This ability to synchronize (or entrain) behaviour and physiology to environmental light-dark cycles is vital for the principal function of the circadian clock: to serve as an internal predictor of external time, and in doing so to facilitate adaptation to environmental changes. In mammals, the central circadian pacemaker resides in the suprachiasmatic nucleus (SCN) of the hypothalamus, which serves as the gateway through which light acts on the rest of the circadian timing system. Inter- as well as intra-cellular communication are essential for the proper functioning of the SCN clock.