Direct stimulation of nerves with 0.1, 0.5 and 1.0 mA for a) intact nerves, and 8 weeks following b) resection, c) autograft repair, d) neurograft repair, e) repair with empty tube. Vertical axis ticks represent 1 mV, horizontal time axis ticks represent 1 ms. Constant electrical artifact signifies current onset (empty tube electrically silent, electrical artifact present at low mV).