Spatial performance was individually assessed by recording traverse times (min: s: ms), i.e. the time taken to move from the entrance to the finish line (5 min = incomplete), as well as recoding the progress through the maze as the time difference to move between lines A to E, judged on the placement of a front leg across the line. Emotional reactivity was not assessed in this study, as only a few vocalizations, escape attempts, urinations and defecations were observed at 83 and 95 weeks of age.