Female C57BL/6 mice show consistent individual differences in spontaneous interaction with environmental enrichment...

Environmental enrichment typically improves learning, increases cortical thickness and hippocampal neurogenesis, reduces anxiety, and reduces stereotypic behaviour, yet sometimes such effects are absent or even reversed. We investigated whether neophobia governs how mice interact with enrichments, since this could explain why enrichments vary in impact. Female C57BL/6 mice, previously screened for neophobia, had free access to enriched cages connected to their standard cages. The relative consumption of food in each cage revealed approximate dwelling times; the use of two enrichments was also measured. High neophobia significantly predicted reduced use of the enriched cage. Thus even within this homogeneous population, provided with identical enrichments, differential neophobia predicted differential enrichment use.