En route to next-generation nerve repair: static passive magnetostimulation modulates neurite outgrowth

Objective. Regeneration of damaged nerves is required for recovery following nervous system injury. While neural cell behavior may be modified by neuromodulation techniques, the impact of static direct current (DC) magnetic stimulation remains unclear. Approach. This study quantifies the effects of DC magnetostimulation on primary neuronal outgrowth in vitro. The extension of neurites of dorsal root ganglia (DRG) subjected to two different low-strength (mT) static magnetic flux configurations was investigated. Main results. After 3 d of 1 h in-plane (IP) magnetic field stimulation, a 62.5% increase in neurite outgrowth area was seen relative to unstimulated controls. The combined action of in-plane + out-of-plane (IP + OOP) magnetic field application produced a directional outgrowth bias parallel to the IP field direction. At the same time, the diverse magnetic field conditions produced no changes in two soluble neurotrophic factors, nerve growth factor and brain-derived neurotrophic factor, released from resident glia. Significance. These results demonstrate the potential for DC magnetostimulation to enhance neuronal regrowth and improve clinical outcomes.