Cross-species intracerebral grafting of embryonic swine dopaminergic neurons

Neural grafting techniques may have clinical application in the treatment of Parkinson's disease, and a single graft can cause significant behavioral recovery in rodent models of striatal dopaminergic denervation. This chapter demonstrates that mesencephalic tissue from embryonic porcine litters provides a viable source of dopaminergic tissue that is appropriately integrated into the chronically immunosuppressed rat host. The results demonstrate that xenografts of embryonic porcine dopaminergic neurons survive, when transplanted into chronically immunosuppressed hosts from a widely divergent phylogenetic order. Suspension grafting techniques are used in this experiment for several reasons, such as the technique makes it possible to transplant combined tissue from multiple donors, resulting in a significant amplification of transplanted material. The findings presented in the chapter suggest that xenogeneic grafts from animals that breed in litters, such as swine, may provide enough tissue for transplantation into patients with Parkinson's disease, and it is expected that these grafts can be appropriately integrated into the human striatum as they are in experimental animal models. However, the chapter also addresses several problems that need to be addressed, if xenografts are to become clinically useful.