title: Peripheral nerve regeneration through grafts of living and freeze-dried CNS tissue.
abstract: The ability of peripheral nerve fibres to regenerate through the central nervous system (CNS) extracellular matrix in the presence of CNS myelin debris was examined using living and freeze-dried optic nerve grafts. The grafts were placed end-to-end with the proximal stumps of severed common peroneal nerves of inbred mice. Within a 4 week period, regenerating peripheral nervous system fibres were found in only two of 14 living grafts. However axons always grew into freeze-dried grafts within one week, despite the presence of CNS myelin debris. The regenerating axons in freeze-dried grafts were accompanied by Schwann cells and were initially found associated with the inner aspect of the glial basal lamina. Although the extracellular matrix of the freeze-dried CNS tissue was subsequently reorganized by invading cells, it seems likely that neither the nature of the CNS extracellular matrix nor the presence of CNS myelin debris had a major inhibitory influence on peripheral nerve regeneration. It is suggested that the presence of living astrocytes covered by a basal lamina at the proximal end of the living optic nerve grafts may inhibit their penetration by regenerating axons.
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000502:physiology; D001485:Basement Membrane / Q000502:physiology; D005109:Extracellular Matrix / Q000502:physiology; D005260:Female; D005612:Freeze Drying; D051379:Mice; D008808:Mice, Inbred CBA; D009416:Nerve Regeneration; D009900:Optic Nerve / Q000637:transplantation*; D014021:Tissue Preservation