Mrosovsky N
Department of Zoology, University of Toronto, Ontario, Canada.
J Biol Rhythms. 1989 Fall;4(3):365-70. doi: 10.1177/074873048900400305.
The adjustment of hamsters to advanced light-dark (LD) cycles can be greatly accelerated by scheduling a single 3-hr bout of extra activity in a novel running wheel, starting about 7 hr before the time when the animals become active in the preceding LD cycle. The present experiments were designed to provide stronger evidence that this effect depends on a shift in the pacemaker rather than on masking. It was shown that when hamsters were put into continuous darkness (DD) 1 day after the exercise-accelerated phase shift, their free-running rhythms took off from a time nearer to the onset of darkness in the new LD cycle than in the preceding LD cycle. An incidental finding was that in DD the free-running period of the hamsters with the accelerated phase shifts was longer than that of the control animals. Further evidence that the 3-hr exercise pulse had produced a greater phase advance than that occurring in undisturbed control animals was obtained by giving a light pulse at the same clock time to all animals after they had been in DD for 8 days. The animals that had previously exercised for the additional 3-hr phase-advanced in response to the light pulse, while the undisturbed control animals phase-delayed.
通过安排在一个新颖的跑轮中进行一次3小时的额外活动，可以极大地加速仓鼠对提前的明暗（LD）周期的适应，该活动大约在动物在前一个LD周期开始活跃前7小时开始。本实验旨在提供更有力的证据，证明这种效应取决于起搏器的转变而非掩盖作用。结果表明，当仓鼠在运动加速的相移后1天被置于持续黑暗（DD）环境中时，它们的自由运行节律从比前一个LD周期更接近新LD周期黑暗开始的时间点开始。一个偶然的发现是，在DD环境中，经历加速相移的仓鼠的自由运行周期比对照动物的更长。在所有动物处于DD环境8天后，在相同的时钟时间给它们一个光脉冲，从而获得了进一步的证据，表明3小时的运动脉冲比未受干扰的对照动物产生了更大的相位提前。之前进行了额外3小时运动的动物对光脉冲产生了相位提前的反应，而未受干扰的对照动物则出现了相位延迟。
