Effects of delayed amputation on denervated forelimbs of adult newt.

Left forelimbs of adult newts were repeatedly denervated prior to and following amputation. Limb amputations were performed at 7-, 14-, 21-, 27-and 45-day intervals after the initial denervation. Regeneration was found in the sham-denervated and control animals but did not occur in any of the experimental cases; instead cicatrix formation and dermal wound healing ensued. Soft-tissue dedifferentiation was evident, however. We conclude from these results that forelimb regeneration in the adult newt is completely nerve dependent (for growth).