Abstract: Objective To explore the effect of intracerebroventricular injection of AR-M1896, a galanin receptor 2 agonist, on depression- like behavior in rat chronic mild stress (CMS) model. Methods 48 Sprague-Dawley rats were randomly assigned into control group, CMS group, CMS artificial cerebrospinal fluid (aCSF) group and CMS AR-M1896 group equally. The control group received no intervention, and the other groups were established chronic mild stress model. After six-week of stress, forced swim test and sucrose preference test were conducted to identify the CMS rats. AR-M1896 or aCSF was injected into the lateral ventricle of CMS AR-M1896 group and CMS aCSF group, respectively. The immobility time and climbing time in the forced swim test were analysed, and the sucrose consumption percentage in the sucrose preference test was measured. Results The immobility time decreased (F=11.998, P<0.01), climbing time increased (F= 8.268, P<0.05), and the sucrose consumption percentage increased (F=10.352, P<0.01) in CMS AR-M1896 group, compared with CMS aCSF group. Conclusion Intracerebroventricular administration of galanin receptor 2 agonist AR-M1896 is effective on depression in CMS model rats.

Key words: chronic mild stress, depression, galanin receptor 2 agonist, rats