A multielectrode array for intrafascicular recording and stimulation in sciatic nerve of cats

The feasibility of implanting an array of penetrating electrodes into perip heral nerves is studied in acute experiments in the cat sciatic nerve. A no vel, silicon-based array of microelectrodes, the Utah Electrode Array, was used, which contains 25 or 100 1-mm long electrodes that project out from a silicon substrate. Electrode arrays of this complexity, when inserted in t he peripheral nerve, could cause significant compression of the nerve and b lock the conduction of action potentials. Using a high velocity insertion t echnique, the electrode array was implanted into the sciatic nerve. Compoun d action potentials were evoked by and recorded with cuff electrodes. Compo und action potentials recorded 1 h after insertion were only slightly alter ed from those recorded before insertion. Single units were readily extracte d from evoked multiunit neural recordings in response to cutaneous stimulat ion and limb rotation around joints. Current injections into the nerve thro ugh the electrodes evoked muscle twitches with currents in the 10 mu A rang e. Recording and stimulation stability were demonstrated for periods of up to 60 h. We have shown that high density arrays of electrodes can be insert ed into the peripheral nerve and can provide a stable recording and stimula ting interface to individual peripheral nerve axons. Such an array may be u seful in future neuroscience research and potential neuroprosthetic applica tions. (C) 2000 Elsevier Science Inc.