As described in several different chapters of this book, neural transplantation has been used extensively during the past two decades as a model for neural development and maturation, as well as a screening tool for different factors that might affect these processes. In addition, neural transplantation of fetal neurons is considered a plausible avenue for treatment of different neural degenerative diseases, such as Parkinson’s disease (PD) (for review, see Hoffer et al., 1988 ; Bakay and Herring, 1989 ; Granholm et al., 1989 ; Lindvall et al., 1990 ; Hitchcock, 1995 ; Kordower et al., 1995 ). PD has served as the prototype for study of transplantation in neurodegenerative disease, perhaps because, in patients with PD, a set of conspicuous symptoms is caused by loss of neurons in a single nucleus, the substantia nigra pars compacta (Shults, 1992 ).