Abstract: Objective To observe the changes of hippocampal neurons, Nissl body and GPR30 expression on castrated rats after ovarian transplantation，for evaluating the protective effect of ovarian transplantation on hippocampal neurons. Methods The adult SD rats were divided into control group(sham operation)，castration group(excision of two ovaries) and transplantation group(transplantation of ovary of 3 days neonate rat under the renal capsule after castration ). 7, 14, 21 and 28d after the ovarian transplantation, the brains were removed for evaluating the morphologic change of hippocampal neurons, amount of Nissl bodies and the expression of GPR30 by Nissl staining, immunohistochemistry and Western-blot in three groups.Results Normal hippocampus and plentiful Nissl bodies were seen in control group, the GPR30 was expressed in cytoplasm of hippocampus neurons. Compared with the control group, the layers of hippocampus neurons were reduced and shrinkage of cytoplasm and nuclei were seen in hippocampus neurons. The amount of Nissl bodies and expression of GPR30 were decreased time-dependently in the castration group, and increased time-dependently in the transplantation group with recovery of neuron structures. Conclusion The ovarian transplantation can reverse the morphological changes of castration-induced hippocampus neurons and improve the expression of GPR30 protein, and promote the recovery of protein synthesis function in hippocampal neurons.

Key words: ovarian castration, ovarian transplantation, hippocampal neurons, GPR30