Effects of different forms of environmental enrichment on behavioral, endocrinological, and immunological parameters in male mice (2003)

Marashi, V., Barnekow, A., Ossendorf, E. et al.

Abstract

Animals were kept in groups of four males under three different housing conditions: (A) nonstructured Makrolon type III laboratory cages ( standard-housing = S); (B) equivalent laboratory cages that were enriched with a box and a scaffolding ( enriched-housing = E); and (C) spacious terraria that were structured richly ( super-enriched-housing = SE). Both forms of enrichment caused a sharp rise in aggressive behavior, though play behavior was increased in E and SE mice, too. Plasma corticosterone concentrations and adrenal tyrosine hydroxylase activities were significantly increased in male mice kept in both forms of enriched cages. .The behavioral and endocrinological differences were partly reflected by immunological parameters. .. Despite the elevated levels of stress hormones under both forms ofenriched housing, the behavioral parameters also indicate positive effects of the enrichment, especially on SE animals. Obviously, an environmental enrichment is beneficial for male mice as long as the spatial conditions are generous enough to allow coping with the increased aggression brought about by the enrichment.