Intranasal OT improved the DSS-induced abnormal stress-related behavior of mice
Analysis of the WAST results indicated that the IBD mice showed a decreased tendency to explore (Fig.1A), spent more time immobile (Fig.1B) and were less willing to self-care, compared with the mice in the control group (Fig.1C). Thus, DSS treatment induced an abnormal stress response in the IBD mice. Following intranasal OT treatment, the IBD mice recovered their motivation to explore, spent less time being immobile, and were more willing to self-care. However, the effects of intranasal OT were nullified in the intranasal OT + intranasal atosiban co-treated IBD mice (Fig.1A-C).
Intranasal OT restored DSS-induced hippocampal change of gene expression
We next investigated the role of the nNOS/NO, BDNF and ERK signaling pathways of the hippocampus in abnormal stress-related behavior. We also examined whether intranasal OT attenuated DSS-induced abnormal stress-related behavior through these pathways2829,30. While the expression of nNOS/NO, OTR, pERK/ERK and BDNF increased in the hippocampus of the IBD mice, intranasal OT treatment caused the expression of these genes to return to normal levels (Fig.2A-F). Again, intranasal atosiban co-treatment attenuated many of the effects of intranasal OT except its effect on OTR and BDNF expression (Fig.2C and F).