Reformation of long axon pathways in adult rat central nervous system by human forebrain neuroblasts

• Published in: Nature (London) 1990-10, Vol.347 (6293), p.556-558
• Main Authors: Wictorin, Klas, Brundin, Patrik, Gustavii, Björn, Lindvall, Olle, Björklund, Anders
• Format: Article
• Language: English
• Subjects: Animals; Axonal Transport; Axons; Axons - physiology; Brain; Brain - physiology; Brain - ultrastructure; Brain Tissue Transplantation; Cellular biology; Central nervous system; Cerebral Cortex - physiology; Cerebral Cortex - ultrastructure; Corpus Striatum - physiology; Corpus Striatum - ultrastructure; Cortex; Female; Fetal Tissue Transplantation; Fluorescent Dyes; Forebrain; Humanities and Social Sciences; Humans; Implants; letter; Membrane proteins; multidisciplinary; Neostriatum; Nerve Regeneration; Nervous system; Neuroblasts; Neurons; Neurons - physiology; Neurons - transplantation; Neurons - ultrastructure; Neurosciences; Oligodendrocytes; Peripheral nerves; Pontine nuclei; Rats; Rats, Inbred Strains; Rhombencephalon - embryology; Rhombencephalon - transplantation; Science; Spinal cord; Spinal Cord - physiology; Spinal Cord - ultrastructure; Substantia nigra; Substantia Nigra - physiology; Substantia Nigra - ultrastructure; Telencephalon; Telencephalon - embryology; Telencephalon - transplantation; Transplants & implants
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/347556a0

THE failure of lesioned axons to regenerate over long distances in the mammalian central nervous system (CNS) is not due to an inability of central neurons to regenerate, but rather to the non-permissive nature of the CNS tissue environment 1–4 . Regenerating CNS axons, which grow well within a peripheral nerve, for example, fail to penetrate mature CNS tissue by more than about 1 mm 1,5,6 . Recent evidence indicates that this may be due to inhibitory membrane proteins associated with CNS oligodendrocytes and myelin 2–4,7,8 . We report here that human telencephalic neuroblasts implanted into the excitotoxically lesioned striatum of adult rats can escape or neutralize this inhibitory influence of the adult CNS environment and extend axons along major myelinated fibre tracts for distances of up to ∼20 mm. The axons were seen to elongate along the paths of the striato-nigral and cortico-spinal tracts to reach the substantia nigra, the pontine nuclei and the cervical spinal cord, which are the normal targets for the striatal and cortical projection neurons likely to be present in these implants.