Neural Transplantation in the Developing CNS

Since the advent of modern neurotransplantation research about two decades ago, considerable attention has focused on its potential use in the treatment of neurodegenerative disorders, particularly Parkinson’s disease. However, although clinical application is limited to a few medical centers, other pure experimental studies have added considerable knowledge of the basic principles of development and plasticity of the central nervous system (CNS). This is evident in studies involving neural grafting into adult, as well as newborn, recipients. However, neural grafting into the developing CNS is by nature particularly suited for addressing fundamental questions of nervous system growth and development, because it relates for example to neuronal cell division, differentiation, and migration, as well as to axonal elongation and axon-target interactions, trophic mechanisms, and neural plasticity and repair. Clinical application of neuronal transplantation in the newborn is not imagined in the near future, although nervous system damage remains the most common birth defect (e.g., hypoxic-ischemic encephalopathy occurs in approx 2–4 neonates/1000 liveborn at term), but experimental neurotransplantation provides intriguing data regarding repair of the damaged neonatal brain and spinal cord.