Modification of retrograde degeneration in transected spinal axons of the lamprey by applied DC current

摘要: In the spinal cord of lamprey, regeneration giant reticulospinal axons occurs following transection. We show that partial degeneration proximal axonal segment, or “die-back,” also transection and it precedes regenerative outgrowth. The die-back during first 5 days post-transection is reduced significantly by application a 10-microA DC current across site transection, with cathode distal to lesion. Reversing polarity applied (cathode lesion) increases extent relative sham-treated controls. Following saline-filled wick electrodes were implanted in body musculature on either side Electrically treated animals received lesion for days, while sham- controls no current. After several each preparation injected intracellularly dye Lucifer Yellow. stump was determined filled fibers measuring distance axon end from mean distances as follows: controls, 1750 microns +/- 45 SEM; cathode-distal, 740 33 cathode-proximal, 2820 60 SEM. These differences between treatment groups proved be significant using Wilcoxon rank sum test. propose caused entry cations driven into cut surface endogenous injury interacts decrease increase flow cord, depending direction This turn causes corresponding reduction enhancement die-back.