Longitudinally implanted intrafascicular electrodes for stimulating and recording fascicular physioelectrical signals in the sciatic nerve of rabbits.

The purpose of this experiment was to determine the stimulating and recording characters of fascicular physioelectrical signals in the activity of peripheral nerves by longitudinally implanted intrafascicular electrodes (LIFEs) in a rabbit sciatic nerve model, and discuss the future application of LIFEs in functional electrical stimulation (FES) and control of electric arm prosthesis. In methodology, LIFEs were inserted into the fasciculus of the sciatic nerves of rabbits and used as recording electrodes and stimulating electrodes, respectively. Motor-evoked potentials (MEPs), cortical somatosensory-evoked potentials (CSEPs), and electromyography (EMG) were recorded by using a transcranial stimulation system (TCS). LIFEs were found to have stable stimulating and recording characters. The interpeak amplitudes (IPAs) of MEPs ranged from 78-156 microV (mean +/- SD, 102 +/- 23.2 microV). The onset latency (OL) of MEPs ranged from 9.8-11.2 msec (mean +/- SD, 10.8 +/- 0.6 msec). The interpeak amplitudes (IPAs) of CSEPs ranged from 5.8-7.2 microV (mean +/- SD, 6.7 +/- 0.5 microV). The onset latency (OL) of CSEPs ranged from 11.4-14.6 msec (mean +/- SD, 12.8 +/- 1.3 msec). EMGs could be recorded in the gastrocnemius, but could not be recorded in the tibialis anterior muscle. In conclusion, longitudinally implanted intrafascicular electrodes can act as intrafascicular stimulating and recording electrodes with high selective characters. They can provide a new way to study fascicular physioelectrical signals and their function in the activity of peripheral nerves. Copyright 2003 Wiley-Liss, Inc.