The first experiments with neural transplantation into the brain (for a
review, see Bjorklund and Stenevi 1985) were reported at the end of the
last century by Thompson (1890), who took cortical tissue from adult
cats and implanted the tissue pieces into the neocortex of adult dogs.
The neurons did not survive, but the transplanted mass did not
disintegrate entirely. Successful graft- ing into the brain was reported
later by Ranson (1909), who implanted spinal ganglia into the cerebral
cortex of developing rats, and by Dunn (1917), who reported survival of
implanted neonatal cortex into the cortex of newborn recipients. Another
important step was made by Le Gros Clark (1940) who reported that, in
the rabbit, embryonic (E) cortical tissue could be successfully grafted
into the cortex of young recipients. Ex- periments by Wallace and Das
(1982), and Bjorklund and Stenevi (1984), showing behavioral effects of
grafts, subsequently stimu- lated a growing interest in
neurotransplantation research. Intrac- erebral grafting is now
considered a powerful tool for addressing fundamental questions about
development, regenerative, or re- storative phenomena in the central
nervous system (CNS) and is a potential therapy for neurodegenerative
diseases.