Abstract: Objective To observe the synapse formation in hippocampal dentate gyrus, and the memory ability after transplanting bone marrow stromal cells (BMSCs) into lateral ventricle of ischemic brain injury rats. Methods BMSCs from femur of a Sprague-Dawley rat were cultured for 3 generations in vitro. 60 newborn Sprague-Dawley rats were divided into sham group (n=20), model group (n=20) and BMSCs group (n=20). The latter 2 groups were ligated the left common carotid artery, and the BMSCs group were injected BMSCs into the lateral ventricle 7 days after ligation. They were tested with Morris's water maze 8 weeks later, and then, the brains were immunohistochemical staining to detect synaptophysin (SY). Results The time of probe trial of acquisition phase (T1) and reveral phase (T2) decreased in the model group compared with the sham group (P<0.05), and increased in the BMSCs group compared with the model group (P<0.05). The integral optical density (IOD) of SY positive cells decreased in the model group compared with the sham group (P<0.05), and increased in the BMSCs group compared with the model group (P<0.05). Conclusion BMSCs implantation through lateral ventricle can improve the learning and memory ability of rats, which may associated with the synapse formation in dentate gyrus.

Key words: bone marrow stromal cells, transplantation, ischemia, brain injury, synapse, memory