In vivo CNS remyelination: HNK-1 labels newly differentiated oligodendrocytes but not precursors.

The possibility that HNK-1 antibody might identify oligodendrocyte precursors in vivo was investigated using a combined immunocytochemical and ultrastructural analysis of remyelination in the cat optic nerve after demyelination induced by local injection of antiserum against galactocerebroside. HNK-1 antibody, in addition to antisera to galactocerebroside, glial fibrillary acidic protein, vimentin and myelin basic protein, was applied to early and late premyelinative lesions within which we have recently identified a putative precursor for the remyelinating oligodendrocyte termed the small glial cell. HNK-1 labelled oligodendrocytes in normal optic nerve and newly differentiated oligodendrocytes within lesions but did not label the small glial cells.