Effect of applied electrical fields on sprouting of intact saphenous nerve in adult rat

Saphenous nerve sprouting was measured behaviorally and histologically after chronic sciatic denervation in the adult rat. The effect of electrical stimulation (either weak DC fields, or stronger AC fields) on the rate of sprouting of the intact saphenous was studied. Sprouting was enhanced by DC fields (1 μA) if the cathode was placed distal to the growth tips, but was unaffected by anode stimulation. Sprouting was also enhanced by AC fields (1000 μA per pulse) given at 20 Hz and 0.1 ms duration. In the discussion we postulate that separate mechanisms might mediate the AC and DC results. The DC effects are the first demonstration in mammals of results previously observed in lower vertebrates.