Figure 2. Permanent effects of neonatal novelty exposure on social competitive success and stress response system function (24 months of age).
AB. When trained individually, Novel and Home rats showed no difference in learning to obtain chocolate rewards nor did they differ in final level of performance (N Novel = 11, N Home = 11). C. During paired social competition testing, Novel rats won significantly more rewards than Home rats on Day 1 but not on Day 2 (N = 11 pairs of Novel and Home rats). D. Novel but not Home rats exhibited a significant reduction in wins from Day 1 to Day 2. E. Despite a significant difference between Novel and Home rats in wins on Day 1, there was no parallel difference in post-competition corticosterone (CORT) concentration. Overall, CORT response to social competition significantly decreased across testing days (N = 14 pairs of Novel and Home rats). F. Novel but not Home rats exhibited significant habituation of CORT response across days. In all panels, data are mean±SEM; * indicates p<0.05; ns indicates p>0.05.