Fetal porcine dopaminergic cell survival in vitro and its relationship to embryonic age

One of the critical factors in the survival of embryonic neural grafts is t he age at which the population of donor neurons is harvested. This is espec ially the case for the developing dopaminergic neurons in the embryonic ven tral mesencephalon, which are used for neural grafts in Parkinson's disease (PD). The donor age for optimal harvesting of these cells has been well ch aracterized in the mouse, rat, and marmoset, and to a lesser extent in huma ns. However, the best donor age for porcine ventral mesencephalic tissue ha s not been ascertained, even though the use of this tissue for xenografts h as been explored both experimentally and clinically. In this study the effe ct of donor age on dopaminergic cell survival was assessed in vitro, from a range of fetal pigs aged from E24 to E35. The number of tyrosine hydroxyla se (TH)-positive cells per ventral mesencephalon was then calculated after 1 and 7 days in culture. E26-E27 embryos gave the highest yield of such cel ls at both survival time points, suggesting that this will be the optimal a ge for harvesting tissues whether for experimental or clinical nigral xenog raft programs.