Figure 1. EdU staining.

A. EdU staining has a low and homogeneous background. a. EdU staining of a transverse brain section in a 120 day-old mouse one hour post EdU injection. b. 3D surface plot of the area is outlined with a white box on panel (a). c. EdU positive nuclei identified with Find Maxima Process (Fiji image processing package). Each identified nucleus is shown as a magenta dot surrounded by a white crosshair. B. 60% of dividing cells become labeled with EdU two hours after EdU injection. A section of the brain of a 120 day-old mouse stained for phospho-Histone H3 to identify mitotic cells (pH3), EdU (EdU) and phospho-Histone H3 and EdU (pH3+EdU) double stained. a. One hour after EdU injection. b–d. Two hours after EdU injection. Panel b shows a cell at the prophase stage of cell cycle; panel c shows two cells at the metaphase stage; and d a cell at the anaphase stage. e, f. Pie charts showing the number of nuclei stained positive for phospho-Histone H3 alone (blue) and phospho-Histone H3 and EdU (red) ((e) one hour and (f) two hours after EdU injection). C. Structure of the lateral ventricles of the brain of a 120 day-old mouse. The structure was reconstructed using serial transverse sections of the mouse brain, (a) Frontal and (b) lateral view. D. EdU-labeled nuclei are stained through the entire thickness of brain sections. Maximum intensity projections of a 50 µm transverse section of the brain stained for EdU. A point of the rostral migratory stream departure for the anterior end of the caudoputamen is shown. a, Projection along X axis; b, along Z axis; and c, along Y axis. Section thickness along Z axis are shown with brackets. 120 days-old mouse one hour post EdU injection.