Transplantation of fetal cortex to the brain of newborn rats: a retrograde fluorescent analysis of callosal and thalamic projections from transplant to host.

Fetal cerebral cortical tissue was transplanted into the cerebral hemisphere of 0-1-day-old rats. In some cases, the transplants were placed into or adjacent to cortical lesion cavities made immediately prior to transplantation. Injections at maturity of fast blue and diamidino yellow into the host contralateral cortex and ipsilateral thalamus demonstrated the presence of callosal and thalamic projections from transplant to host. Numerous single-labeled neurons were often arranged in cell bands or clusters. This apparent topography and the absence of double-labeling resembled normal labeling patterns.