Embryo implantation and decidualization are crucial for successful pregnancy,which include multiple genes and signaling pathways,while the precise mechanism regarding embryo implantation and decidualization has yet to be explored.The GABA which activates GABA_(A)or GABA_(B)receptors has been found playing an important role in early pregnancy.Here we seek to investigate whether GABA_(B)receptors participate in embryo implantation in mice.This study first characterized the spatiotemporal expression pattern of GABA_(B)receptors in the uterus during the peri-implantation period and found that GABA_(B1)expression was drastically upregulated in stromal cells on days 4e6,a period of embryo implantation and early stages of decidualization.Embryo delayed implantation and oil-induced decidualization models were further used to confirm that the GABA_(B1)was associated with embryo implantation and decidualization.We also found estrogen or progesterone had no directly effect on expression of GABA_(B1)in ovariectomized model.Because we were unable to detect significant GABA_(B2)which couples with GABA_(B1)to form whole GABA_(B)receptors,and the agonist and antagonist of whole GABA_(B)receptors had weak effect on the proliferation and differentiation of stromal cells as well,we excluded the possibility whole GABA_(B)receptors function,and concluded it should be non-classical signals of GABA_(B1)involving in embryo implantation and decidualization.Future studies should focus on investigating the roles and mechanisms of GABA_(B1)during embryo implantation and decidualization.
