Effects of EGb761 on synaptophysin expression in hippocampus of vascular dementia rats

AIM: To investigate the effects of Ginkgo biloba extract 761 (Egb761) on synaptophysin (SYN) expression in hippocampus of vascular dementia (VD) rats.METHODS: VD rat models, established by repeatedly cerebral ischemia/reperfusion, were randomly divided into two groups: model group and EGb761 treated group (both n=30), and another 30 condition-matched rats were selected as the sham-operated controls. Spatial learning and memory abilities of rats were assessed by Morris water maze (MWM) task, and SYN expression in hippocampal formation of rats in different groups was detected by immunohistochemical technique and image analysis.RESULTS: The MWM escape latency (EL) in model group was highly longer than that in the sham-operated group (P<0.01), while the EL of EGb761-treated group was significantly shorter than that in model group, but still longer than that in the sham-operated group at 1 m, 2 m and 4 m after VD modeling operation (P<0.05 or P<0.01). Immunohistochemical analysis showed that the SYN immunoreactive expression in hippocampal formation in model group greatly decreased and mean optical density of SYN expression highly increased compared with both sham-operated group and EGb761-treated group at three time points (P<0.01).CONCLUSION: EGb761 can increase the expression of SYN in hippocampus, which may be one of important mechanisms of EGb761 in improving learning and memory dysfunction of VD rats.