Transplantation of CNS fragments into the brain of shiverer mutant mice: extensive myelination by implanted oligodendrocytes. I. Immunohistochemical studies.

Solid fragments of olfactory bulb from new-born normal (B6CBA and C57BL6) mice were implanted into new-born shiverer (shi/shi) brains. The shiverer mouse being characterized by the absence of myelin basic protein (MBP), myelination due to implanted oligodendrocytes can be detected in the shiverer brain using an antiserum anti-MBP. Observation of sagittal sections of the host brains revealed very extensive areas of normal myelination from the level of the graft (rostral thalamus) up to the caudal brain (diencephalon, cerebellum, pons). Thus, oligodendrocytes contained in the implant migrate out of the graft over long distances in the host brain, before they differentiate and synthesize myelin. These results raise the question of the behaviour of oligodendrocytes in normal development.