CNS myelin and oligodendrocytes of the Xenopus spinal cord--but not optic nerve--are nonpermissive for axon growth.
In vitro assays reveal that myelin and oligodendrocytes of the Xenopus spinal cord (SC) are--unlike corresponding components of the optic nerve/tectum (OT)--nonpermissive substrates for regenerating retinal axons. The number of growth cones that crossed SC oligodendrocytes is low but increases significantly (four- to fivefold) in the presence of the antibody IN-1, in which case their numbers are similar to the number of growth cones (approximately 60%) that cross OT oligodendrocytes with or without IN-1. IN-1 neutralizes neurite growth inhibitors (NI) of rat CNS myelin, indicating that mammalian-like NI are associated with Xenopus SC myelin and oligodendrocytes but not with the OT. IN-1 immunocytochemistry on sections supports this view: SC myelin was stained with IN-1, whereas OT myelin and PNS myelin were not.
Lang
D M
DM
University of Konstanz, Faculty of Biology, Germany.
Rubin
B P
BP
Schwab
M E
ME
Stuermer
C A
CA
D000818:Animals; D001369:Axons / Q000502:physiology*; D006054:Goldfish; D006131:Growth Inhibitors / Q000378:metabolism; D007120:Immunochemistry; D008675:Metamorphosis, Biological; D009186:Myelin Sheath / Q000502:physiology*; D009413:Nerve Fibers, Myelinated / Q000378:metabolism; D009416:Nerve Regeneration; D009836:Oligodendroglia / Q000502:physiology*; D009900:Optic Nerve / Q000502:physiology*; D012160:Retina / Q000502:physiology / Q000648:ultrastructure; D013116:Spinal Cord / Q000502:physiology*; D013477:Superior Colliculi / Q000502:physiology; D014981:Xenopus / Q000235:genetics
D006131:Growth Inhibitors