Effects of electrical stimulation on motor function and the expressions of microtubule-associated protein-2 and survivin after cerebral infarction in rats

Abstract

Objective To investigate the effects of unilateral and bilateral electrical stimulation of the upper and lower limbs on motor function following cerebral infarction and the expressions of microtubule-associated protein-2 (MAP-2) and survivin in the infarction border zone of rats. Methods Adult male Sprague-Dawley (SD) rats were randomly divided into sham operation, control, impaired limb and bilateral limbs electrical stimulation groups (each group included 32 rats). Acute cerebral infarction was mimicked using a middle cerebral artery occlusion tech-nique. After cerebral infarction for 24 h, the rats were treated daily with or without electrical stimulation. A beam walking test (BWT) was used to measure limbs motor function and immunohistochemistry and HE staining were used to detect the expressions of MAP-2 and survivin in the border zone of infarcted area after electrical stimulation treat-ment for 3, 7, 14 and 21 d. Results Comparet with the control group treatment with electric stimulation led to BWT scores increasing significantly, and bilateral stimulation was more potent in ameliorating motor function thanstimulating the impaired limb only. The expression of MAP-2 was significantly higher in eleetrieal stimulation groups than in control group from the 7th of treatment, and it was higher in bilateral stimulation group than that in unilateral stimulation group from tbe 14th day of treatment. There was no significant difference in MAP-2 expression between bi-lateral stimulation group and sham operation group at the 21st day of treatment. In electrical stimulation groups, at every time point the expressions of survivin were obviously higher than that in sham operation group, and it was higher than that in control group and peaked at the 7tb and 14th day of treatment and in bilateral stimulation group it was no-tably higher than that in unilateral stimulation group. At the 21st d of treatment the level of survivin expression drop-per; however, there was no significant difference between unilateral and bilateral electrical stimulation groups. Con-clusions Treatment with electrical stimulation, particularly in bilateral limbs stimulation, could induce MAP-2 and survivin expressions in the infarction border zone of rats. It also could promote the recovery of motor function in para-lyzed limbs after cerebral infarction of rats. The improvement might involve the up-regulation of MAP-2 and survivin expressions. Key words: Motor function; Cerebral infarction; Electrical stimulation; Microtubule-assoeiated protein-2; Survivin