Effects of CES on functional recovery and brain remodeling in a rat model of stroke

CHEN Qi; XU Yu-jiao

doi:10.3969/j.issn.1001-9448.2017.05.003

Abstract：Objective To evaluated the effects of implanted cortical electrical stimulation (CES) on functional recovery and brain remodeling in a rat model of stroke.Methods Seventy Sprague-Dawley rats were submitted to middle cerebral artery occlusion (MCAO) for 120 min.Two days after MCAO,MRI was used to verify the anatomical location of stroke and identify the placement of the surface electrode over the peri-infarct cortex.Rats with lesions involving cortex were randomly divided into the CES group (n =13) and no stimulation (NS) group (n =10).One week after MCAO,we used cortical electrodes to deliver electrical stimulation for 2 h daily over 2 weeks to the rats in CES group,but not to the rats in NS group.Body weight (BW) was monitored in the 2-week stimulation and 4-week observation period,and behavioral tests were performed on Days 2,5,8,11,14,17,20,23,26,29,32,35,38 and 41 after the electrode implantation.Finally,rats in both CES and NS groups were sacrificed for immunohistochemistry.Results Compared to NS group,BW of rats in CES group was significantly higher in the 2-week stimulation and 4-weekd observation period (F =5.757,P =0.026).Limb placement test,foot fault test and beam walking test demonstrated that CES significantly enhanced functional recovery.Immunohistochemical study shown that CES enhanced angiogenesis and dendritic sprouting and suppressed inflammatory response in the ischemic cortex.CES also promoted dendritic sprouting and suppressed inflammatory response in the contralesional cortex.Conclusion These results suggest the stimulation protocol is safe,and greatly improves functional recovery and brain remodeling in the 4 weeks following 2 weeks stimulation.