Physiologic Electrical Fields Direct Retina Ganglion Cell Neurite Growth

Restoration of vision in patients with advanced optic neuropathies such as glaucoma requires regenerating the optic nerve (ON). The current rate-limiting step to ON regeneration is directing axons of newly transplanted cells to grow out of the retina to their distant targets. Much of the current effort to address this problem aims at recapitulating the molecular neurotropic signals that directed ON growth during development. However, studies have shown that their presence alone is insufficient to support axon growth of transplanted RGCs. The body has naturally occurring electrical currents that have been shown to exert neurotropic effects on motor neurons and dorsal root ganglion cells. The effects of an electrical field (EF) on RGC growth, however, have never been tested before. Here, we demonstrate for the first time that RGC axons grow directionally towards the cathode when exposed to an EF.