Cage enrichment and mouse behaviour (2004)

Wolfer, D. P., Litvin, O., Morf, S. et al.

Abstract

Mice housed in standard cages show impaired brain development, abnormal repetitive behaviours (stereotypies) and an anxious behavioural profile, all of which can be lessened by making the cage environment more stimulating. But concerns have been raised that enriched housing might disrupt standardization and so affect the precision and reproducibility of behavioural-test results. Here we show that environmental enrichment increases neither individual variability in behavioural tests nor the risk of obtaining conflicting data in replicate studies. Our findings indicate that the housing conditions of laboratory mice can be markedly improved without affecting the standardization of results. ..Our findings should be generally applicable, for example in drug-screening or lesion studies. And they should also apply to animals physiology or anatomy, which are, in any case, less sensitive than behaviour to environmental perturbations. It remains to be seen whether our conclusions also apply to male mice, who may respond to enrichment with enhanced dominance behaviour and aggression. But for females, environmental enrichment should improve the animals well-being without reducing the precision and reproducibility of the data derived from them, while attenuating abnormal brain function and anxiety--both of which are potential confounds in animal experiments.