Figure 1: Experimental timeline for the comparison of control and novel object exposure. (a) For animals exposed to novel objects, 2 animals were housed together for over 2 weeks. They were brought to the laboratory and housed there until the next day when they were placed on a lab bench, the cage lid was removed, and 2 identical LEGO objects were placed in the cage center about 6 inches apart. After 5 min, the objects were removed. After 90 min, one animal was perfusion fixed, and 20 min later the remaining animal was perfused. For this series of experiments, mice were not acclimated to objects prior to testing. (b) For control mice, procedures were the same as (a), but objects were not placed in the cage.