TIME COURSE OF SPROUTING DURING MUSCLE REINNERVATION IN VITAMIN E-DEFICIENT RATS

A typical aspect of motoneuron plasticity is the sprouting which occurs during muscle reinnervation, resulting in a transitory multiple innervation of the muscle cells. In order to verify the effect of a decreased protection from free radical attack on the sprouting, the multiple innervation in the extensor digitorum longus muscle, following sciatic nerve crush and regeneration, was studied in vitamin E‐deficient rats. Thus, the innervated end‐plates and the end‐plates with multiple innervation were studied with histochemical and electrophysiological techniques. The percentage of innervated end‐plates was similar in both groups at 30 as well as at 60 days after nerve crush. Nevertheless, multiple innervation was found in a larger part of the muscle and it lasted longer in the deficient rats. This finding is discussed in relation to some of the major hypotheses of sprouting; it may be relevant in the treatment of some lesions of peripheral nerve. Copyright © 1990 John Wiley & Sons, Inc.