Dallmann R, Mrosovsky N
Department of Zoology, University of Toronto, Ontario, Canada.
Physiol Behav. 2006 Jul 30;88(4-5):459-65. doi: 10.1016/j.physbeh.2006.04.022. Epub 2006 Jun 14.
It is often stated that light is the primary environmental cue (zeitgeber) for entrainment of circadian clocks. Here, we use a new conflict test design in Syrian hamsters comparing the strength of a photic zeitgeber to that of a non-photic cue, i.e. wheel availability. Re-entrainment to an inverted LD cycle was significantly slowed down in the nocturnal hamster by restricting wheel access to the light phase of the inverted LD cycle. This effect is more pronounced if the illuminance level of the entraining lights is 0.1 lx compared to 6 lx. In this conflict design, the hamsters did not re-entrain to an inverted LD cycle for up to four weeks (when the experiment ended), but voluntarily ran during the light phase. This approximates the situation in people subjected to shift work or jet lag.
人们常说，光是使生物钟同步的主要环境信号（授时因子）。在此，我们在叙利亚仓鼠中采用了一种新的冲突测试设计，比较光授时因子与非光信号（即跑轮可用性）的强度。通过将跑轮使用限制在倒转的明暗周期的光照阶段，夜行性仓鼠重新适应倒转的明暗周期的速度显著减慢。与6勒克斯相比，当同步光照的照度水平为0.1勒克斯时，这种影响更为明显。在这种冲突设计中，仓鼠在长达四周的时间里（实验结束时）都没有重新适应倒转的明暗周期，而是在光照阶段自愿跑动。这类似于从事轮班工作或遭受时差反应的人的情况。
