Rodent models are commonly used in behavioral research because they offer increased experimental control and findings often generalizable to humans. However, one possible dilemma is that rodents are primarily nocturnal and research tasks often disrupt their light, rest phase. The present study used a within-subjects design to investigate possible effects of light-dark phase on delay discounting, motor coordination, open field, and elevated-plus maze behavior in Wistar rats. Rats spent significantly more time in the closed arms of the elevated plus maze when tested during the light, rest phase compared to the dark, active phase. There were no differences in motor coordination or delay discounting during the two phases. These results suggest possible important differences in certain behavioral tasks when testing in the light, rest versus dark, active phase for rats—researchers should be aware of these possible differences when planning and conducting experiments and when comparing research findings across laboratories.

啮齿动物模型通常用于行为研究，因为它们提供了增强的实验控制和发现，通常可以推广到人类。然而，一个可能的困境是啮齿动物主要是夜行性的，研究任务经常破坏它们的轻度休息阶段。本研究采用受试者内部设计来研究明暗相对Wistar大鼠延迟贴现，运动协调，开阔视野和高迷迷宫行为的可能影响。与在黑暗中活跃的阶段相比，在明亮，静止阶段进行测试时，大鼠在高架迷宫的闭合臂上花费的时间明显更多。在两个阶段中，运动协调或延迟贴现没有差异。这些结果表明，在明亮，静止与黑暗环境下进行测试时，某些行为任务可能存在重要差异。