Cain Sean W, Ko Caroline H, Chalmers Jennifer A, Ralph Martin R
Departments of Psychology and Zoology, University of Toronto, 100 St. George Street, Room 4020, Toronto, Ontario, Canada M5S 3G3.
Neurobiol Learn Mem. 2004 May;81(3):217-20. doi: 10.1016/j.nlm.2004.02.003.
In golden hamsters, the expression of a conditioned place preference (CPP) or avoidance (CPA) is regulated in a circadian pattern such that the preference and avoidance are exhibited strongly at the circadian time of prior training, but not at other circadian times. In the rat, reports are conflicting regarding whether time of day learning is evident. We investigated whether this conflict arises because different strains of rat have been used. In this experiment, Long Evans and Wistar rats were trained at a specific circadian time to discriminate between a context paired with food reward and an unpaired context. Animals were then tested for preference at the same or a different circadian time. Long Evans rats showed preference for the paired context at both times tested, whereas Wistar rats showed preference only when training and testing times matched. The results show that time of day learning can be generalized to rats using the Wistar strain.
在金黄地鼠中，条件性位置偏好（CPP）或回避（CPA）的表达受昼夜节律模式调控，使得偏好和回避在先前训练的昼夜节律时间强烈表现出来，但在其他昼夜节律时间则不然。在大鼠中，关于一天中不同时间的学习是否明显，报告存在冲突。我们研究了这种冲突是否因使用了不同品系的大鼠而产生。在本实验中，将长 Evans 大鼠和 Wistar 大鼠在特定的昼夜节律时间进行训练，以区分与食物奖励配对的环境和未配对的环境。然后在相同或不同的昼夜节律时间对动物进行偏好测试。长 Evans 大鼠在两个测试时间都表现出对配对环境的偏好，而 Wistar 大鼠仅在训练和测试时间匹配时才表现出偏好。结果表明，一天中不同时间的学习可以推广到使用 Wistar 品系的大鼠。
