Variability of enriched environment does not enhance the enrichment effect on food neophobia in rats (Rattus norvegicus)

Abstract

Many studies report differences between animals raised in an enriched environment and those living in standard conditions. Animals reared in enriched conditions demonstrate better memory and learning abilities, increased activity, reduced level of anxiety, etc. However, there is a shortage of studies investigating the impact of environmental variability on animal behaviour, and few studies on this topic focus on animals with different initial anxiety levels. This study was conducted on laboratory rats. Prior to the experiment, the rats were kept in three types of rearing conditions: an enriched stable environment; an enriched variable environment; and in standard laboratory conditions. The environment was enriched by providing a cognitively and physically stimulating living space. The variability of the environment involved altering the arrangement of the enriching objects on a daily basis. The level of reaction to food novelty was measured with a food neophobia test. The study demonstrates that an enriched environment has a significant impact on reducing food neophobia. However, our findings suggest that the variability of the environment is not necessary and does not enhance the positive impact of enrichment on these aspects of behaviour.

Keywords: Affordances; Environmental enrichment; Food neophobia; Neophobia; variable environment.