THE EFFECTS OF MULTIPLE SEQUENTIAL EPISODES OF DEMYELINATION IN THE SCIATIC NERVE OF THE MOUSE

Abstract

Intraneural injections of lysophosphatidylcholine [LPC] were used to examine the effects of multiple episodes of demyelination and repair in the sciatic nerves of adult mice. The early phases of repair, from initiation of myelinolysis to the appearance of promyelinated fibers, were achieved more rapidly in multiple-injected nerves than in single-injected nerves. This lead was temporary, since subsequent remyelination was delayed in the multiple-injected nerves until several days after it was established in most single-demyelinated nerves. Cell-mediated demyelination was seen in multiple-injected nerves, but never in single-injected nerves. The results are discussed in times of the contribution of the supernumerary Schwann cells to the acute stage of the program of cellular repair and the possibility that the normal response to an injection of LPC in a nerve which has previously undergone several episodes of demyelination is exacerbated by a local and self-limiting immune-mediated reaction.