Phenotyping Circadian Rhythms in Mice.
Phenotyping Circadian Rhythms in Mice.
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DOI：
10.1002/9780470942390.mo140229
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发表时间：
2015-09-01
影响因子：
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通讯作者：
Sassone-Corsi P
中科院分区：
文献类型：
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作者：
Eckel-Mahan K;Sassone-Corsi P
昼夜节律以二十四小时为周期发生，时间上跟随地球绕其轴的旋转。昼夜节律的例子有睡眠/觉醒周期、进食和激素分泌。光有力地带动了哺乳动物的生物钟，并通过激活大脑“中央起搏器”——视交叉上核中的特定神经元，帮助动物与地球的 24 小时周期保持同步。当动物处于持续黑暗或“自由奔跑”条件下时，动物的绝对周期性可能会稍微偏离 24 小时。在自由运行条件下对生物体活动的简单测量揭示了其固有的昼夜节律周期。由于易于基因操作，小鼠是研究昼夜节律的特别有用的模型，从而识别节律的分子贡献者。此外，它们的小尺寸允许相对轻松地监测其家庭笼子环境中的运动或活动。这里概述了通常用于分析小鼠昼夜节律周期性和可塑性的几个任务，包括夹带过程、自由奔跑条件下 tau（周期长度）的确定、响应光干扰的昼夜节律周期性的确定（即时差研究）以及非二十四小时条件下的时钟可塑性评估（T 周期）。研究昼夜节律周期的特性，例如响应光扰动的相位、幅度和长度，对于了解人类如何应对时差、夜班、轮班或其他短暂或慢性的环境破坏特别有用。
Circadian rhythms take place with a periodicity of twenty-four hours, temporally following the rotation of the earth around its axis. Examples of circadian rhythms are the sleep/wake cycle, feeding, and hormone secretion. Light powerfully entrains the mammalian clock and assists in keeping animals synchronized to the 24-hour cycle of the earth by activating specific neurons in the “central pacemaker” of the brain, the suprachiasmatic nucleus. Absolute periodicity of an animal can deviate slightly from 24 hours as manifest when an animal is placed into constant dark- or “free running”- conditions. Simple measurements of an organism's activity in free running conditions reveal its intrinsic circadian period. Mice are a particularly useful model for studying circadian rhythmicity due to the ease of genetic manipulation, thus identifying molecular contributors to rhythmicity. Furthermore, their small size allows for monitoring locomotion or activity in their home cage environment with relative ease. Several tasks commonly used to analyze circadian periodicity and plasticity in mice are outlined here including the process of entrainment, determination of tau (period length) in free running conditions, determination of circadian periodicity in response to light disruption (i.e. jet lag studies), and evaluation of clock plasticity in non-twenty-four hour conditions (T-cycles). Studying the properties of circadian periods such as their phase, amplitude, and length in response to photic perturbation, can be particularly useful in understanding how humans respond to jet lag, night shifts, rotating shifts, or other transient or chronic disruption of one's environmental surroundings.