Objective： To observe the effects of electroacupuncture （EA） on the structure parameters of synapse and reactive changes of astrocyte in the marginal zone of focal cerebral ischemia in rats at different time zones so as to further explore its underlying mechanisms in the treatment of cerebral ischemia. Methods： Ninety male Wistar rats were randomly assigned to sham-operation, model, and EA groups, with 30 animals in each group. Each group was subdivided into 1 h, as well as 1, 3, 7, and 21 days post-operation groups, with 6 animals assigned to each time point subgroup. Heat coagulation-induced occlusion of the middle cerebral artery was performed to establish a model of focal cerebral ischemia. EA was applied immediately following surgery to the EA group [4/20 Hz, 2.0-3.0 V, 1-3 mA, to Baihui （GV20） and Dazhui （GV14）] for 30 min. Treatment was performed once a day, and experimental animals were sacrificed at 1 h, as well as 1, 3, 7 and 21 days postoperation. The ultrastructure changes in synapse and astrocytes were observed by using transmission electron microscopy. Glial fibrillary acidic protein （GFAP） expression and Ca2＋ of astrocytes were measured by using laser confocal scanning microscope. Excitatory amino acid transporters-2 （EAAT2） and connexin 43 （CX43） expressions were assayed with immunohistochemical method. Canonical correlation analysis was conducted between structure parameters of synapse and parameters of astrocyte in the same time and group. Results： Broken synapses were observed following cerebral ischemia, and the numbers of synapses were significantly decreased. Compared with the model group, synaptic ultrastructure was significantly improved in the EA group. Compared with the sham-operation group, synaptic number density was significantly decreased, as were postsynaptic density thickness, synaptic cleft width and synaptic interface curvature in the EA and model groups. However, compared with the model group, postsynaptic density thickness was significantly incre
