Transplantation of labeled fetal spinal cord fragments into juvenile myelin‐deficient rat spinal cord

Minced and triturated fragments from the spinal cord of normal rat fetuses (15–18 days gestation) labeled with the fluorescent dye fast blue (FB) were successfully transplanted into juvenile myelin‐deficient rat spinal cord under direct observation. Clusters of myelinated fibers were found subsequently in the recipient spinal cord, and, by fluorescence microscopy, clusters of FB‐labeled cells were found at corresponding sites. The results indicate that the surgical approach used is suitable for transplantation of tissue fragments into a defined region of juvenile rat spinal cord, that FB can be used to locate the transplanted cells subsequently, and that FB does not interfere with maturation of the donor glia or with myelin formation.