Physiologically compatible electrical stimulation of schwann cells enhances primary neurite outgrowth

This study investigates neuron response to electrically stimulated Schwann cells (SC) for neural engineering applications. Following injury, regenerating axons must navigate the injury and restore connections with distal targets. Previous results show moderate electrical stimulation (50 mV/mm) of SC-neuron co-cultures increases neurite outgrowth. To isolate the effect of any electrically mediate changes in Schwann cell phenotype, DC field of 50 mV/mm was applied to primary neonatal rat SC for 8 hours. Following stimulation, electrically stimulated SC conditioned medium was collected and the electrically stimulated SC recovered in new media for 12 hours. Primary dissociated neurons were seeded on 1) the electrically-stimulated SC or 2) in the electrically-stimulated SC conditioned medium and allowed to grow 12 hours. Results indicate that neurons grown on electrically stimulated SC exhibited a 3.2× increase in neurite outgrowth and a 2.8× increase in longest neurite compared to unstimulated SC controls. We observed increases in outgrowth in the conditioned medium. Neurons cultured in electrically stimulated SC conditioned media exhibit a 1.18× increase relative to their unstimulated SC controls. Appropriate application of electrical stimulation in vivo may contribute to the repair of injured nerves via electrically mediated changes to the neural and non-neural cells.