Effect of functional electrical stimulation on limb motor function and extra cellular signal-regulated kinase expression in adult rats with spinal cord injury

Abstract

Objective To investigate the protective effect of functional electrical stimulation on limb motor function and its mechanism in rats with spinal cord injury. Methods One hundred and twenty healthy adult SD rats were randomly divided into sham-operated group, model group, and functional electrical stimulation (FES) group (n=40). The rats in the latter two groups were replicated as spinal cord injury models on T9 using NYU method; and only laminectomy without spinal cord injury was performed in rats of the sham-operated group; FES was performed in rats of the functional electrical stimulation group 8 h after model making. One d, and one, two, and four weeks after model making, 10 rats in each group were chosen for experiment, respectively; BBB scale was used to evaluate the motor function of the rats; immunohistochemical staining was used to detect the extra cellular signal-regulated kinase (ERK) expression in the injured spinal cords; ERK mRNA expression in the injured spinal cords was detected by real-time PCR. Results As compared with rats in the control group, rats in the model group and FES group had significantly decreased BBB scale scores and statistically increased ERK protein and mRNA expressions at each time point after injury (P<0.05). One, two, and four weeks after model making, rats in the FES group had significantly higher BBB scale scores and statistically lower ERK protein and mRNA expressions than rats in the model group (P<0.05). Conclusion FES can protect the spinal cords by inhibiting the ERK expression in the injured areas, thereby improving the limb motor function of rats with spinal cord injury. Key words: Functional electrical stimulation; Spinal cord injury; Extra cellular signal-regulated kinase; BBB scale