Objective: To detect the changes in protein location and expression level of 5-hydroxy tryptamine3B receptor in related regions of hippocampus and hypothalamus in rats with depression emotion (DE)

to explore the intervention mechanism of Shuyu capsule for treating DE preliminarily. Method: The Wistar rats were divided into normal group

model group

Shuyu capsule group(0.4 g ·kg-1) and fluoxetine group(0.002 g ·kg-1). Then we used the chronic mild stress(CMS)to establish the DE model in rats

and then the rats were evaluated by sucrose intake and the body weight from beginning to the end for the model. We adopted the immune fluorescence to detect the protein distribution and expression levels of 5-HT3B receptor in related region of hippocampus and hypothalamus

and to calculate the content of the receptors in the regions by the mean fluorescence intensity(MFI) as the index. Result: Compared with the normal group

the body weight of rats in DE model group lessened significantly (P<0.01)

the sucrose intake of preference also decreased obviously (P<0.01)

the expression of the receptor of 5-HT3B had a significant increase in hippocampus and hypothalamus (P<0.01). Compared with the model group

in the Shuyu capsule group and fluoxetine group

the body weight of rats in DE model group increased significantly (P<0.01)

the sucrose intake of preference also increased obviously (P<0.01)

the expression of the receptor of 5-HT3B was increased markedly in hippocampus and hypothalamus (P<0.01)

however

there was no statistical differences in the two treatment groups. Conclusion: The high expression of 5-HT3B receptor may have close relationship with DE

and Shuyu Capsule can correct the high expression of the 5-HT3B receptor protein in the hippocampus and hypothalamus of DE model in rats.