Laboratory rodents raised in environmentally-enriched (EE) cages differ behaviourally and cognitively from conventionally-housed (CH) animals. We hypothesised that mice can detect such differences, testing this using differentially-raised female C57BL/6 s as subjects, and differentially-raised female BALB/cs and DBA/2 s as stimuli, in Social Approach Tests. Because more prone to signs of depression, anxiety, stereotypic behaviour (SB) and aggression, we further hypothesised that CH mice would be less sociable and socially attractive than EE mice. A novel familiarisation paradigm pre-exposed subjects to non-cagemate EE and CH stimulus mice before testing in Social Approach Tests. CH subjects proved less sociable than EE subjects: an effect unrelated to general exploration, anxiety or depression-like traits, and driven specifically by reduced interest in CH stimulus mice. Providing further evidence that CH and EE stimulus mice could be distinguished, subjects proved most attracted to mice from housing unlike their own. CH subjects thus preferred EE over CH stimulus mice, while EE subjects tended to prefer CH over EE: patterns that were not mediated by any measured aspect of stimulus mouse behaviour. Differential bodyweight also seemed unimportant, as was scent: soiled CH and EE bedding/nesting did not elicit the same discrimination. Instead, subjects who avoided CH stimulus mice and were attracted to EE stimulus mice were those who received the most agonism in their home cages. Together this provides the first demonstration that mice can distinguish between individuals raised in enriched or conventional cages, and suggests that receiving agonism from cagemates may motivate mice to seek new, less-aggressive companions.

在环境丰富 (EE) 笼子中饲养的实验室啮齿动物在行为和认知上与传统饲养 (CH) 动物不同。我们假设小鼠可以检测到这种差异，在社交方法测试中使用差异饲养的雌性 C57BL/6 s 作为受试者进行测试，并将差异饲养的雌性 BALB/cs 和 DBA/2s 作为刺激物进行测试。因为更容易出现抑郁、焦虑、刻板行为 (SB) 和攻击性的迹象，我们进一步假设 CH 小鼠比 EE 小鼠更不善于交际和缺乏社交吸引力。在社交方法测试中进行测试之前，一种新的熟悉范式将受试者预先暴露于非笼养 EE 和 CH 刺激小鼠。CH 受试者被证明不如 EE 受试者善于交际：这种影响与一般探索、焦虑或抑郁样特征无关，并特别受到对 CH 刺激小鼠的兴趣降低的驱动。提供了可以区分 CH 和 EE 刺激小鼠的进一步证据，证明受试者最被来自与他们自己不同的住房的小鼠所吸引。因此 CH 受试者更喜欢 EE 而不是 CH 刺激小鼠，而 EE 受试者倾向于喜欢 CH 而不是 EE：模式不受刺激小鼠行为的任何测量方面的介导。体重差异似乎也不重要，气味也不重要：脏的 CH 和 EE 床上用品/嵌套不会引起相同的区分。相反，避开 CH 刺激小鼠并被 EE 刺激小鼠吸引的受试者是那些在其家笼中受到最多激动的人。这一起提供了第一个证明小鼠可以区分在丰富或传统笼子中饲养的个体，