(A) Histological appearance of the subventricular zone/ventricular zone of the neocortices of a comparison case (26 GWs) and an extremely preterm infant with white matter injury (WMI) (24 GWs at birth, survived 22 days). Sections were stained with H&E (HE) and immunostained with anti-nestin antibody and anti-Musashi antibody. Scale bar: 50 μm. (B) Sections of neocortices of a comparison case (6 years old) and an extremely preterm infant with WMI (24 GWs at birth, survived 6 years) immunostained for MAP2. High-magnification images of boxed areas of white matter (WM) are shown. Scale bar: 50 μm. (C) MAP2-positive cells and NeuN-positive cells in the white matter were quantified by counting the number of these cells in 10 randomly acquired digitized high-power field images (original magnification, ×20). The numbers of MAP2-positive cells and NeuN-positive cells per field are shown (n = 30 fields from 3 different brains, respectively). ***P < 0.001, Welch’s t test. Each point represents an individual field. Box-and-whisker plots were used to graphically represent the median (line within box), upper and lower quartiles (bounds of box), and maximum and minimum values (top and bottom bars).