
Fig. 4. Pdgfra+ cells from embryonic rat brain differentiate in vitro into GC+ oligodendrocytes or (GFAP+, A2B5+) type-2 astrocytes. These cells were immunoselected from whole brain, but similar results were obtained with cells from cortex or basal ganglia. (A) More than 99% of the process-bearing cells were NG2+. These cells were also (PDGFRA+, A2B5+, O4-, GC-) (not shown). (B) After culturing for a further 2-3 days in the presence of 0.5% FCS without added PDGF-AA more than 99% of the cells differentiated into GC+ oligodendrocytes. (C,D) If the immunoselected cells were instead cultured in the presence of 10% FCS, more than 99% of the cells became GFAP+ astrocytes (C), many of which also labelled with A2B5 (D). Scale bar, 50 µm.