Marashi Vera, Barnekow Angelika, Sachser Norbert
Department of Behavioral Biology, University of Münster, Badestr. 9, D-48149 Münster, Germany.
Physiol Behav. 2004 Oct 15;82(5):765-76. doi: 10.1016/j.physbeh.2004.05.009.
Environmental enrichment is intended to improve the welfare of laboratory animals. However, regarding male mice, numerous studies indicate an increase in aggressive behavior due to cage structuring. On the one hand, this might be a problem concerning animal welfare. On the other hand, enrichment is though to hamper environmental standardization and to increase variability of data. Furthermore, increasing fights, arousal, and/or injury in enriched housed animals might superimpose other (positive) environmental effects on behavior and physiology. Therefore, the present study investigated effects of environmental enrichment on behavioral, endocrinological, and immunological parameters in male mice of the docile inbred strain ABG. From weaning until day 77+/-3 of life, animals were kept in stable sibling groups of four 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 scaffolding ("enriched housing"=E); and (C) spacious terrariums that were structured richly ("super-enriched housing"=SE). No differences in agonistic behavior, levels of plasma corticosterone (CORT), and activities of adrenal tyrosine hydroxylase (TH) existed among S-, E-, and SE-housed ABG males. Play behavior and general activity increased significantly with increasing enrichment. Concerning immunological parameters, males of both forms of enriched housing showed significantly lower percentages of CD4 and CD8 cells compared to S-housed mice. However, regarding the ratio of CD4/CD8 cells, IL-2, IL-4, IL-10, IFN-gamma, IgG1, and IgG2a, no significant housing-dependent differences were found. Enrichment did neither hamper standardization nor negatively influence the variability of physiological parameters. In summary, using a docile strain of mice revealed the positive effects of environmental enrichment also on male mice. The lack of adverse effects on behavior, physiology, standardization, and variability of data defuses these arguments against providing docile male mice with enrichment.
环境富集旨在改善实验动物的福利。然而，对于雄性小鼠而言，大量研究表明，由于笼舍结构的原因，攻击性行为会增加。一方面，这可能是一个关乎动物福利的问题。另一方面，富集被认为会妨碍环境标准化并增加数据的变异性。此外，富集饲养的动物中不断增加的争斗、兴奋和/或伤害可能会将其他（积极的）环境影响叠加在行为和生理上。因此，本研究调查了环境富集对温顺近交系ABG雄性小鼠行为、内分泌和免疫参数的影响。从断奶到生命的第77±3天，动物以四只一组的稳定同窝分组饲养在三种不同的饲养条件下：（A）无结构的III型 Makrolon 实验室笼舍（“标准饲养”=S）；（B）配备箱子和脚手架的等效实验室笼舍（“富集饲养”=E）；以及（C）结构丰富的宽敞玻璃容器（“超富集饲养”=SE）。S组、E组和SE组饲养的ABG雄性小鼠在攻击行为、血浆皮质酮（CORT）水平和肾上腺酪氨酸羟化酶（TH）活性方面没有差异。随着富集程度的增加，玩耍行为和总体活动显著增加。关于免疫参数，与S组饲养的小鼠相比，两种富集饲养形式的雄性小鼠CD4和CD8细胞的百分比均显著降低。然而，关于CD4/CD8细胞比例、白细胞介素-2、白细胞介素-4、白细胞介素-10、干扰素-γ、免疫球蛋白G1和免疫球蛋白G2a，未发现显著的饲养依赖性差异。富集既没有妨碍标准化，也没有对生理参数的变异性产生负面影响。总之，使用温顺的小鼠品系揭示了环境富集对雄性小鼠也有积极影响。对行为、生理、标准化和数据变异性没有不利影响，消除了反对为温顺雄性小鼠提供富集环境的这些论点。
