CONDITIONALLY IMMORTALIZED OLIGODENDROCYTE CELL-LINES MIGRATE TO DIFFERENT BRAIN-REGIONS AND ELABORATE MYELIN-LIKE MEMBRANES AFTER TRANSPLANTATION INTO NEONATAL SHIVERER MOUSE BRAINS

Five immortalized oligodendrocyte cell lines, representing a spectrum of different stages of oligodendrocyte maturation, were transplanted i nto neonatal shiverer mouse brains and examined for their ability to s urvive, multiply, and migrate in vivo. Each of the cell lines migrated to different regions of the brain with remarkable consistency when in jected into the mouse forebrain, suggesting that the cells might be re sponding to different environmental cues present in the neonatal mouse brain. These results are consistent with the fact that cells at diffe rent stages in the oligodendrocyte lineage probably possess different sets of surface molecules and receptors. Significant differences were also observed in the survival and proliferation of the lines examined, even when the lines tested had quite similar in vitro phenotypes. Int erestingly, the cell line with the most mature in vitro phenotype, N20 .1, appeared to elaborate membranous processes when transplanted into the brain, reminiscent of oligodendrocytes ensheathing axonal segments . The experiments suggest that these immortalized cells could be usefu l models to study the cellular and molecular mechanisms involved in th e development, maturation and possibly formation of myelin by oligoden drocytes in the mammalian brain.