The effect of transcranial electrical stimulation on functional recovery and the expression of microtubule-associated protein-2 and growth-associated protein-43 after cerebral focal ischemia

Abstract

Objective To assess the influence of transcranial electric stimulation (TES) on the recovery of motor function after cerebral focal ischemia and reperfusion and to explore the mechanisms in terms of neural plasticity.Methods An acute focal ischemia-reperfusion model was established by transient occlusion of the right middle cerebral artery (MCAO).Seventy-two male Sprague-Dawley rats were randomly divided into a TES group,a model group,a sham-operation group and a normal group.The TES group was given TES 24 h after MCAO;the model group received the operation without any treatment.Forelimb placing (FPT) and beam walking (BWT) were mea-sured at the 3rd,7th,14th and 28th day after reperfusion.Microtubule-associated protein-2 (MAP-2) and growth-associated protein-43 (GAP-43) and grey levels of reaction products in the peri-infarct region were examined by immunohistochemical techniques.Results The TES group rats had markedly better FPT and BWT performance at the 7th,14th and 28th day after MCAO,compared with the model group.Expression of MAP-2 had increased significantly more at the 14th and 28th day in the peri-infarct region in the TES group compared with the model group.Expression of GAP-43 was significantly elevated in the peri-infarct region in the TES group compared with the model group at all time points.Conclusions TES can improve motor function and neural plasticity following cerebral ischemia and reperfusion damage.The functional enhancement may be partly due to up-regulation of the expression of GAP-43 and MAP-2 in the peri-infarct region. Key words: Cerebral ischemia and reperfusion; Transcranial electrical stimulation; Microtubule-asso-ciated protein-2; Growth associated protein-43; Forelimb placing test; Beam walking test