Experimental demyelinating optic neuropathy induced by intra-neural injection of galactocerebroside antiserum

The morphological changes induced by microinjection of galactocerebroside (Gal-C) antiserum into the rat optic nerve are described. Light and electron microscopic observations were made 2-20 days post-injection. The severity and extent of the lesion varied according to the volume of antiserum injected and the depth of penetration into the nerve. With small volumes of antiserum (1-3 microliters), primary demyelination was the principal change found from 2 days onwards and by 10 days there was evidence of remyelination by oligodendroglia. Some fibres undergoing Wallerian-type degeneration were also found. The injection of larger volumes of antiserum (5-10 microliters) produced a more extensive lesion with marked axonal degeneration in addition to demyelination at the periphery of the lesion. These findings show that Gal-C antiserum can cause demyelination of central nerve fibres when the blood-brain barrier is bypassed.