Optic nerve intraneural stimulation allows selective visual cortex activation

Retinal prostheses have been developed to restore a functional form of vision in patients affected by outer retinal layer dystrophies. Other approaches, namely optic nerve, thalamic, and cortical prostheses are under investigation to expand this toolbox both as clinical devices and as tools for fundamental research. Optic nerve stimulation is attractive since it bypasses the entire retinal network and directly activates nerve fibers. At the same time, it still takes advantage of the high-level information processing occurring downstream in the visual cortex. Here we show that a new intraneural electrode array (OpticSELINE) is effective in inducing the activation of the visual cortex upon electrical stimulation of the optic nerve. We also demonstrate that intraneural optic nerve stimulation induces selective cortical activation patterns depending on the stimulating electrode, thus suggesting that the OpticSELINE possesses spatial selectivity in fiber stimulation. In conclusion, the OpticSELINE can be used both as visual prosthesis for blind patients and as tool to further investigate the effect of the electrical stimulation in the visual system.