Molecular Psychiatry, Laboratory of Translational Neuroscience, Department of Psychiatry, Psychosomatics, and Psychotherapy, University of Würzburg, Fuechsleinstrasse 15, 97080 Wuerzburg, Germany.
Behav Brain Res. 2011 Mar 17;218(1):99-105. doi: 10.1016/j.bbr.2010.11.031. Epub 2010 Nov 24.
Ethologically based animal models are widely used; however, results from different laboratories vary significantly which may partly be due to the lack of standardization. Here, we examined the effects of circadian rhythm, lighting condition and mouse strain (BALB/c and C57BL/6, known to differ in measures of avoidance and risk assessment behavior) on two well established behavioral tests in mice: the Elevated Plus Maze (EPM) and the Open Field (OF). Parameters from both paradigms are commonly used as indices of anxiety-like behavior. BALB/c mice and C57BL/6 mice were independently tested in the morning and at night, in regular laboratory lighting and in the dark. We developed a novel method based on infrared lighting from below, coupled to respective video-tracking equipment, which facilitates standard testing of behavior interference-free in complete darkness. The two mouse strains differed in anxiety-related variables for the EPM in the dark, and for the OF in regular laboratory lighting. Moreover, BALB/c displayed greater anxiety-like behavior than C57BL/6 in the OF but less anxiety-like behavior than C57BL/6 in the EPM. Lighting condition has a major influence on both behavioral tests and this to a considerably larger extent than circadian rhythm. In addition, the lighting condition interacts strongly with the genetic background, producing discriminative differences in the anxiety-related variables depending on mouse strain and lighting condition. These results challenge the comparability of not sufficiently standardized tests of anxiety-like behavior and emphasize the need for controlling environmental variables in behavioral phenotyping.
基于行为学的动物模型被广泛应用；然而，不同实验室的结果差异很大，部分原因可能是缺乏标准化。在这里，我们研究了昼夜节律、光照条件和小鼠品系（BALB/c 和 C57BL/6，已知在回避和风险评估行为方面存在差异）对两种在小鼠中建立良好的行为测试的影响：高架十字迷宫（EPM）和旷场（OF）。这两种范式的参数通常被用作焦虑样行为的指标。BALB/c 小鼠和 C57BL/6 小鼠分别在早上和晚上、在常规实验室光照和黑暗中进行独立测试。我们开发了一种基于下方红外照明的新方法，结合相应的视频跟踪设备，便于在完全黑暗中不受干扰地进行标准行为测试。这两个小鼠品系在黑暗中的 EPM 和在常规实验室光照中的 OF 中存在焦虑相关变量的差异。此外，BALB/c 在 OF 中表现出比 C57BL/6 更高的焦虑样行为，但在 EPM 中表现出比 C57BL/6 更低的焦虑样行为。光照条件对两种行为测试都有重大影响，而且比昼夜节律的影响大得多。此外，光照条件与遗传背景强烈相互作用，根据小鼠品系和光照条件产生不同的焦虑相关变量的区分差异。这些结果挑战了焦虑样行为测试不够标准化的可比性，并强调了在行为表型中控制环境变量的必要性。
