Objective: Our aim was to investigate the protein changes of the expression of γ-aminobutyric acid B2(GABABR2) receptor in primary cultured rat hippocampus neurons

to explore the intervention mechanism of Shuyu capsule for treating depression emotion preliminarily. Method: We used the chronic mild stress(CMS)to establish the depression emotion(DE) model in rats

and then the rats were evaluated by sucrose intake

the body weight and open-field from beginning to the end for the model. Serum of rats in each group was collected and then added into the medium of vitro cultured hippocampus primary neurons. At last the expression of γ-aminobutyric acid B2 receptor was detected with Western blot respectively. Result: Compared with the normal group

the weight

the total score of open field test and the sucrose intake of preference test of rats in depression emotion model group lessened significantly (P<0.01). On the other hand

compared with the depression emotion model group

the weight

the total score of open field test and the sucrose intake of preference test of rats in Shuyu capsule

bupleurum and fluoxetine treatment groups increased significantly(P<0.05 or P<0.01). Western blot demonstrated that the serum of model group rats obviously increased the protein levels of GABABR2 (P<0.01)

compared with the normal control group. While serum of the Shuyu capsule and fluoxetine treatment groups markedly decreased the protein levels of GABABR2 (P<0.05)

the bupleurum group had no difference with the model group

but the trendhad improved. Conclusion: The serum of rats with depression emotion could induce the high expression of GABABR2

the Shuyu capsule may play antidepressants by reducing the expression of GABABR2 in primary cultured rat hippocampus neurons. The bupleurum also has a good antidepressant effect

but the effect is less than Shuyu capsule.