Self-organization of "fibro-axonal" composite tissue around unmodified metallic micro-electrodes can form a functioning interface with a peripheral nerve: A new direction for creating long-term neural interfaces.

Abstract

A long-term peripheral neural interface is an area of intense research. The use of electrode interfaces is limited by the biological response to the electrode material. We created an electrode construct to harbor the rat sciatic nerve with interposition of autogenous adipose tissue between the nerve and the electrode. The construct was implanted for 10 weeks. Immunohistochemistry showed a unique laminar pattern of axonal growth layered between fibro-collagenous tissue, forming a physical interface with the tungsten micro-electrode. Action potentials transmitted across the intrerface showed mean conduction velocities varying between 6.99 ± 2.46 and 20.14 ± 4 m/s. We have demonstrated the feasibility of a novel peripheral nerve interface through modulation of normal biologic phenomena. It has potential applications as a chronic implantable neural interface.