German Centre for the Protection of Laboratory Animals (Bf3R), German Federal Institute for Risk Assessment (BfR), Berlin, Germany.
Departement of Toxicology, Institute of Clinical Pharmacology and Toxicology, Charité-Universitätsmedizin Berlin, cooperate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Berlin, Germany.
PLoS One. 2020 Apr 2;15(4):e0230900. doi: 10.1371/journal.pone.0230900. eCollection 2020.
Reliability of data has become a major concern in the course of the reproducibility crisis. Especially when studying animal behavior, confounding factors such as novelty of the test apparatus can lead to a wide variability of data which may mask treatment effects and consequently lead to misinterpretation. Habituation to the test situation is a common practice to circumvent novelty induced increases in variance and to improve the reliability of the respective measurements. However, there is a lack of published empirical knowledge regarding reasonable habituation procedures and a method validation seems to be overdue. This study aimed at setting up a simple strategy to increase reliability of behavioral data measured in a familiar test apparatus. Therefore, exemplary data from mice tested in an Open Field (OF) arena were used to elucidate the potential of habituation and how reliability of measures can be confirmed by means of a repeatability analysis using the software R. On seven consecutive days, male C57BL/6J, BALB/cJ and 129S1/SvImJ mice were tested in an OF arena once daily and individual mouse behavior was recorded. A repeatability analysis was conducted with regard to repeated trials of habituation. Our data analysis revealed that monitoring animal behavior during habituation is important to determine when individual differences of the measurements are stable. Repeatability values from distance travelled and average activity increased over the habituation period, revealing that around 60% of the variance of the data can be explained by individual differences between mice. The first day of habituation was significantly different from the following 6 days. A three-day habituation period appeared to be sufficient in this study. Overall, these results emphasize the importance of habituation and in depth analysis of habituation data to define the correct starting point of the experiment for improving the reliability and reproducibility of experimental data.
在可重复性危机的过程中，数据的可靠性已成为一个主要关注点。特别是在研究动物行为时，测试仪器的新颖性等混杂因素可能导致数据的广泛变异性，从而掩盖治疗效果，并导致错误解释。为了避免因新奇性引起的方差增加而使数据变异性最小化，并提高各自测量的可靠性，动物通常会在测试前逐渐适应测试环境。然而，目前缺乏关于合理适应程序的已发表的经验知识，而且似乎需要进行方法验证。本研究旨在制定一种简单的策略，以提高在熟悉的测试仪器中测量的行为数据的可靠性。因此，使用在开放式场（OF）测试仪器中测试的小鼠的典型数据来阐明适应的潜力，以及如何通过使用 R 软件进行可重复性分析来确认测量的可靠性。在连续的七天中，雄性 C57BL/6J、BALB/cJ 和 129S1/SvImJ 小鼠每天在 OF 测试仪器中进行一次测试，并且记录了个体小鼠的行为。针对适应过程中的重复试验进行了可重复性分析。我们的数据分析表明，在适应过程中监测动物行为对于确定测量的个体差异何时稳定是很重要的。行进距离和平均活动的重复性值随着适应期的增加而增加，这表明数据的大约 60%的变异性可以用小鼠之间的个体差异来解释。适应的第一天与接下来的 6 天明显不同。在这项研究中，三天的适应期似乎足够了。总的来说，这些结果强调了适应的重要性以及对适应数据的深入分析，以确定实验的正确起点，从而提高实验数据的可靠性和可重复性。
