Effect of Electrical Stimulation on Spinal Cord Injury: In Vitro and In Vivo Analysis

Electrical stimulation influences neural stem cell neurogenesis. We analyzed the effects of electrical stimulation on neurogenesis in rodent spinal cord-derived neural stem cells (SC-NSCs) in vitro and in vivo and evaluated functional recovery and neural circuitry improvements with electrical stimulation using a rodent spinal cord injury (SCI) model. Rats (20 rats/group) were assigned to a sham (Group 1), SCI only (Group 2), SCI + electrode implant without stimulation (Group 3), and SCI + electrode with stimulation (Group 4) groups to count total SC-NSCs and differentiated neurons and evaluate morphological changes in differentiated neurons. Further, the Basso, Beattie, and Bresnahan scores were analyzed, and the motor and somatosensory evoked potentials in all rats were monitored. In vitro, biphasic electrical currents increased SC-NSC proliferation and neuronal differentiation and caused qualitative morphological changes in differentiated neurons. Electrical stimulation promoted SC-NSC proliferation and neuronal differentiation and improved functional outcomes and neural circuitry in SCI models. Increased Wnt3, Wnt7, and β-catenin protein levels were also observed after electrical stimulation. In conclusion, our study proved the beneficial effects of electrical stimulation on SCI. We believe that Wnt/β-catenin pathway activation may be associated with this relationship between electrical stimulation and neuronal regeneration after SCI.