Roberts M H, Xie X
Department of Biology, Clarkson University, Potsdam, NY 13699-5805, USA.
Physiol Behav. 1996 Apr-May;59(4-5):703-8. doi: 10.1016/0031-9384(95)02116-7.
To determine whether the ocular circadian pacemakers of the marine snail Bulla gouldiana exert phase control over the circadian rhythm in locomotor activity, we measured the phase angles for entrainment of the ocular pacemakers and the activity rhythm on four different photoperiods: L:D 15:9, 12:12, 9:15, and 4:20. We found that the phase angle for ocular entrainment was progressively advanced relative to dawn as photoperiod decreased, although the phase was fixed relative to the middle of the day. In contrast, activity began near dusk on all photoperiods. On subsequent release into constant conditions, the free-running locomotor activity commenced near the time of previous activity onset. Thus, activity phase on light cycles represents the entrainment of a light sensitive pacemaker. The resulting lability in phase between ocular and behavioral rhythms in Bulla exposed to light cycles suggests that the ocular pacemakers are not the only determinants of locomotor activity phase in Bulla.
为了确定海蜗牛泡状拟海牛（Bulla gouldiana）的眼昼夜节律起搏器是否对运动活动的昼夜节律施加相位控制，我们在四种不同的光周期下测量了眼起搏器的同步相位角和活动节律：光照：黑暗为15:9、12:12、9:15和4:20。我们发现，随着光周期缩短，相对于黎明，眼同步的相位角逐渐提前，尽管相对于中午，该相位是固定的。相比之下，在所有光周期下，活动都在黄昏附近开始。在随后释放到恒定条件下时，自由运行的运动活动在前一次活动开始的时间附近开始。因此，光周期上的活动相位代表了一个对光敏感的起搏器的同步。暴露于光周期下的泡状拟海牛的眼和行为节律之间相位的这种不稳定性表明，眼起搏器不是泡状拟海牛运动活动相位的唯一决定因素。
