Transplantation of oligodendrocytes and Schwann cells into the spinal cord of the myelin-deficient rat.

Transplantation of oligodendrocytes or Schwann cells into the spinal cord of the newborn myelin-deficient (md) rat, an X-linked myelin mutant, was carried out and the extent of myelination of CNS axons studied. Dissociated glial cell suspensions, prepared from the spinal cords of female litter-mates, were injected into the lumbar spinal cord of 15 md rats and 5 normal litter-mates. In eight of the md rats examined 12 to 21 days post-transplantation patches of myelin produced by the transplanted oligodendrocytes were found in the dorsal or ventral columns. In two rats, small patches of myelination were found in more than one site. The myelin in these patches was positive on immunocytochemical staining for proteolipid protein. These observations were interpreted as evidence of the origin of this myelin from donor oligodendrocytes, as the md rat has an abnormality in synthesis of this protein. In addition, this myelin differed in its ultrastructure from host myelin, having a normal intraperiod line. Injection of cultured Schwann cells also resulted in extensive myelination of axons in the dorsal columns by these cells.