Fig. 6.

Pre-OLs persist as the expansion in the immature OL population occurs at ∼30 weeks. Representative confocal laser microscopic digital images from a case at 31 weeks demonstrate the striking change in the morphology of OL precursors that occurs with the expansion of the immature OL population in the parietal white matter.A, B, A low-power image (A) and detail (B) demonstrate the marked increase in complex multipolar cells visualized here in the mid cerebral white matter with the O4 antibody. C, D, Double immunofluorescent-labeling studies with a biotinylated O4 antibody (C) and the O1 antibody (D) revealed that many of the O4-labeled cells were O4+O1− pre-OLs (arrows) that were interspersed among the O4+O1+ immature OLs. Scale bars: A, B, 100 μm; C, D, 20 μm.