Fig. 1

The cage types used and the time line of this study. A I Overhead and II Side view pictures of the cages. IVC (individually ventilated cage), CC500 (classical open cage with a floor area of 500 cm²) and CC800 (classical open cage with a floor area of 800 cm²) are commonly used cage types for mice housing. B The time line of the study is shown. The mice born in a particular cage type remain in the same cage throughout its life time. The siblings and parents were removed after 5–6 weeks. At the age of 6 months, the behavioral tests were performed, 1 day after which the mice were sacrificed