The effects of functional electrical stimulation on motor function and on the proliferation, migration and differentiation of neural stem cells in the subventricular zone

Abstract

Objective To investigate the effects of functional electrical stimulation (FES) on motor function and on the expression, proliferation, migration and differentiation of endogenous neural stem cells in the subventricular zone (SVZ) after cerebral ischemia. Methods Middle cerebral artery occlusion (MCAO) was used to induce a model of cerebral ischemia in 108 rats using the modified Zea-Longa method of intraluminal filament occlusion. They were then randomly divided into an FES group, a placebo stimulation group and a control group with 36 cases in each. Superficial FES electrodes were pasted on the paralyzed forelimbs of the rats in the first two groups, though FES treatment was administered only to the FES group beginning on the 3rd day after the MCAO operation. The stimulation was designed to produce extension of the wrist and digits of the paralyzed forelimb. Before, and after 1, 3, 7 and 14 days of the treatment, the neurological deficit was evaluated using modified neurological severity scoring (mNSS). BrdU+ /GFAP+ , BrdU+ /DCX+ and BrdU+ /NeuN+ cells in the SVZ were detected using immunofluorescence technique. Results After 7 and 14 days of treatment, the average motor function of the rats in the FES group had improved significantly when compared with the averages of the other two groups. Compared with the other two groups, the average number of BrdU+ /GFAP+ positive cells in the ischemic SVZ was also significantly greater in the FES group after 7 and 14 days of treatment. After 14 days, BrdU+ /Dcx+ positive cells in the FES group had also increased significantly more, but only a few BrdU+ /NeuN+ cells had appeared in any of the three groups. Conclusion FES can improve motor function after cerebral ischemia, and promote proliferation and differentiation of neural stem cells in the SVZ. Key words: Electrical stimulation; Brain ischemia; Functional electrical stimulation; Neural stem cells; Subventricular zone