Codistribution of neurite growth inhibitors and oligodendrocytes in rat CNS: appearance follows nerve fiber growth and precedes myelination.
Higher vertebrate CNS myelin and oligodendrocytes in vitro contain membrane-bound surface proteins of 35 and 250 kDa with marked inhibitory properties for neurite growth and for fibroblast spreading. The inhibitory activity is neutralized by monoclonal antibody IN-1, which binds to the inhibitory proteins. IN-1 also neutralizes the nonpermissive substrate properties of adult rat optic nerve explants and spinal cord white matter in vitro, thus suggesting a crucial involvement of these inhibitors in the nonpermissive nature of the adult CNS of higher vertebrates. We have determined time of appearance and distribution of the IN-1-sensitive inhibitory activity in the rat. In the optic nerve, inhibitors appear after the period of axonal growth and before myelination. A similar schedule was found for the spinal cord and for the cerebellum. No IN-1-sensitive inhibitory activity was found outside the CNS or in oligodendrocyte-free regions of the CNS. Where investigated, the distribution of inhibitory oligodendrocytes and of IN-1-sensitive inhibitory activity correlated well. Our data suggest that IN-1-sensitive inhibitory activity in vivo might be an oligodendrocyte-specific property.
Caroni
P
P
Brain Research Institute, University of Zurich, Switzerland.
Schwab
M E
ME
D000818:Animals; D000831:Animals, Newborn; D000911:Antibodies, Monoclonal / Q000276:immunology; D002490:Central Nervous System / Q000166:cytology* / Q000254:growth & development; D006131:Growth Inhibitors / Q000276:immunology / Q000378:metabolism*; D007158:Immunologic Techniques; D009186:Myelin Sheath / Q000502:physiology; D009836:Oligodendroglia / Q000166:cytology*; D009900:Optic Nerve / Q000502:physiology; D051381:Rats; D013116:Spinal Cord / Q000502:physiology
D000911:Antibodies, Monoclonal; D006131:Growth Inhibitors