Behaviors over 7 days. Adult females (n=19) and adolescent females (n=15) were subjected to 7 days of repeated social defeat with an aggressive lactating female resident. Following the intruder’s placement in the resident’s cage, resident and intruder were allowed to interact until one of two possible criteria was met: (a) the intruder exhibited a submissive defeat posture (>2 seconds frozen in a supine position), or (b) 15 min. elapsed without defeat. On each of the 7 days, the latency to be defeated was measured. The percentage of rats being defeated on each of the 7 days is shown in the top left and the average number of days that adolescents compared to adults were defeated is shown in the top right. Adolescent rats exhibited an overall significantly longer latency to defeat over the 7 days than did adult rats, shown in the middle left. Similar number of attacks occurred across the 7 days for both age groups, shown in the middle right graph. On each of the seven days of defeat, the latency to first attack was recorded, which is shown in the bottom graph.
# p≤ .05 indicates a significant Age effect with a significant difference between adolescent and adult female rats