Bodden, C. et al. Sci. Rep. 9, 8247 (2019)

To combat issues with reproducibility in animal research, some researchers suggest that rather than trying to standardize as many variables as possible, it might be better to actually switch things up—a concept known as systematic heterogenization. But what variables should—and feasibly can—be varied? A new report in Scientific Reports takes a look at timing.

The researchers conducted several behavioral tests of anxiety and exploratory behavior in female mice from two different strains—C57BL/6J and DBA/2N—at three different testing times: in the morning, at noon, and in the afternoon. The researchers observed behavioral variability between the strains depending on the time—most notably between morning and afternoon tests—but show that simply testing animals across time points can improve the reproducibility of results between replicate experiments.