Publisher Summary This chapter describes the utilization of tissue culture techniques for preparing purified populations of neuronal and nonneuronal cells, combining them in desired proportions, and manipulating the tissue culture environment to achieve the desired level of expression of extracellular matrix components of the nonneuronal cells. Functionally, the implanted rats are not significantly improved over the lesion control rats, and both groups, by three to six months after injury, are almost indistinguishable from normal rats. Thus, implants of cultured sensory neurons and Schwann cells have been shown to survive and, in some instances, fuse with the injured rat spinal cord. Immunocytochemical and electron microscopic studies have demonstrated that Schwann cells did not migrate in any significant number into the injured host spinal cord, but rather glial fibrillary acidic protein (GFAP + ) cells migrated into the implant, thereby accounting for the apparent fusion. The implants have facilitated the growth of developing corticospinal tract fibers beyond the lesion site, causing fasciculation at the dorsal white matter/gray matter junction, and have a greater and more consistent effect, if they are grafted at the time of injury rather than later. However, the addition of pial elements to the cultures does not have a marked effect on implant survival.