Division of Animal Welfare, University of Bern, Bern, Switzerland.
Department of Cell Biology and Biochemistry, School of Medicine, Texas Tech Health Sciences Center, Lubbock, TX, USA.
Sci Rep. 2020 Jul 15;10(1):11684. doi: 10.1038/s41598-020-68549-3.
Poor reproducibility is considered a serious problem in laboratory animal research, with important scientific, economic, and ethical implications. One possible source of conflicting findings in laboratory animal research are environmental differences between animal facilities combined with rigorous environmental standardization within studies. Due to phenotypic plasticity, study-specific differences in environmental conditions during development can induce differences in the animals' responsiveness to experimental treatments, thereby contributing to poor reproducibility of experimental results. Here, we studied how variation in weaning age (14-30 days) and housing conditions (single versus group housing) affects the phenotype of SWISS mice as measured by a range of behavioral and physiological outcome variables. Weaning age, housing conditions, and their interaction had little effect on the development of stereotypies, as well as on body weight, glucocorticoid metabolite concentrations, and behavior in the elevated plus-maze and open field test. These results are surprising and partly in conflict with previously published findings, especially with respect to the effects of early weaning. Our results thus question the external validity of previous findings and call for further research to identify the sources of variation between replicate studies and study designs that produce robust and reproducible experimental results.
较差的可重复性被认为是实验室动物研究中的一个严重问题，具有重要的科学、经济和伦理意义。实验室动物研究中出现相互矛盾的结果的一个可能原因是动物设施之间的环境差异，加上研究内部严格的环境标准化。由于表型可塑性，发育过程中环境条件的特定于研究的差异会导致动物对实验处理的反应性不同，从而导致实验结果的可重复性较差。在这里，我们研究了断奶年龄（14-30 天）和饲养条件（单独饲养与群体饲养）的变化如何通过一系列行为和生理结果变量来影响 SWISS 小鼠的表型。断奶年龄、饲养条件及其相互作用对刻板行为的发展以及体重、糖皮质激素代谢物浓度和高架十字迷宫和旷场试验中的行为几乎没有影响。这些结果令人惊讶，部分与先前发表的研究结果相矛盾，尤其是与早期断奶的影响有关。因此，我们的研究结果对先前研究结果的外部有效性提出了质疑，并呼吁进一步研究，以确定重复研究和产生稳健、可重复实验结果的研究设计之间的变异来源。
