FISH OPTIC-NERVE OLIGODENDROCYTES SUPPORT AXONAL REGENERATION OF FISHAND MAMMALIAN RETINAL GANGLION-CELLS

Segments from adult fish and rat retinae were explanted on myelin-mark er expressing oligodendrocytes derived from the regenerating goldfish optic nerve. Fish axons grew in high density and even rat retinal axon s regenerated to considerable length on the surface of the fish oligod endrocytes, suggesting that this type of fish glia has axon-growth pro moting surface components that exert their influence across species bo undaries. One interesting surface component of the fish oligodendrocyt es as demonstrated here is the E 587 antigen, which is related to the Ll family of cell adhesion molecules. In long term cocultures of oligo dendrocytes and retinal axons, the fish glial cells were found to enwr ap rat axons. This suggests that the oligodendrocytes of the regenerat ing goldfish optic nerve/tract may, despite striking differences, repr esent the equivalent to mammalian optic nerve oligodendrocytes.