Fig. 6

Environmental enrichment (EE) reduced infant SNI-induced anxiety- and depression-like behavior. After EE intervention starting from POD11, a the center distance and b duration were greatly increased on POD 40 in the open field test compared to the group without EE. c The total distance was not different between the four groups. d EE increased sucrose intake percentage compared to the group without EE from POD 25 to POD 45. f Open arm duration was increased on POD 41 after EE when compared to the group without EE. After EE, h the guarding score was decreased and g the paw withdrawal threshold was increased on POD 40 as compared to the SNI group. i EE did not decrease the response to acetone of rats subjected to infant SNI. k SNI decreased center/total distance compared to the sham group, while ICV MIN decreased that effect on POD40. n = 8–9. “a” and “b” denote the statistically significant difference compared to the sham and SNI group, respectively