ABSTRACT
Objective To explore the expression and function of galanin and its receptor in the female mice of anxiety-and depression-like behavior.Methods In situ hybridization was used to detect the expression of galanin,GalR1,GalR2 and GalR3 in the hippocampus of C57BL/6J female mice.A total of thirty female mice was divided into two groups:experiment group (n=15) and control group (n=15).The experiment group was subjected to the chronic unpredictable mild stress (CUMS) for four weeks,and the control group was not subjected to any treatment.Four weeks later,a series of tests were performed on those two groups,including the sucrose preference test,the novel object recognition test,the open field test and suspension tail test.After behavior tests,the hippocampus RNA was extracted from eight mice in each group to test the expression of galanin and its receptor through qPCR.The rest part of mice were used to mark C-Fos immunostaining in the dentate gyms (DG) of hippocampus.Results The result of in situ hybridization showed that galanin,GalR1 and GalR2 distributed in the Hillus of ventral hippocamous,GalR3 had no positive signal.In the sucrose preference test,the experiment group drunk less sucrose when compared with the control group (P＜0.05).In the novel object recognition test,the experiment group contacted shorter time to the novel object when compared with the control group (P＜0.05).In the open field test,the experiment group had shorter in session time when compared with the control group (P＜0.05).In the suspension tail test,the experiment group had longer immobility time when compared with the control group (P＜0.05).The qPCR result showed that the higher expression of galanin and GalR1 in the hippocampus of experiment group (P＜0.05).More C-Fos positive cells in the DG of hippocampus of experiment mice were immunostained (P＜0.05).Conclusions Galanin,GalR1 and GalR2 mainly distribute in the Hillus of the ventral hippocampus.Galanin may be involved in the anxiety-and depression-like behavior of C57BL/6J through GalR1.
ABSTRACT
Objective To explore the effect of intracerebroventricular injection of AR-M1896, a galanin receptor 2 agonist, on depres-sion-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 interven-tion, 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 aC-SF group, respectively. The immobility time and climbing time in the forced swim test were analysed, and the sucrose consumption percent-age 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 aC-SF group. Conclusion Intracerebroventricular administration of galanin receptor 2 agonist AR-M1896 is effective on depression in CMS model rats.