Representative micrographs showing distribution of BrdU-incorporating cells (green) in the uninjured and regenerating RNC (single BrdU injection, 50 mg/kg, followed by a 4 h chase period). The radial glial cells (magenta) are visualized by immunostaining with the ERG1 monoclonal antibody. Nuclei are stained with propidium iodide (PI, blue). All micrographs are longitudinal sections with the plane of injury/regenerate to the left. (A) The RNC of an uninjured animal. The inset shows a high maginification view of a BrdU-incorporating radial glial cell. (B) Early post-injury phase (day 1). The inset shows a higher magnification view of the boxed area. (C, C’) Late post-injury stage (day 6 post-injury). Note numerous BrdU-incorporating cells among the dedifferentiating radial glia. (C’) shows higher magnification of the boxed area in (C) (dedifferentiating region of the RNC). (D) Growth phase (day 8 post-injury). Note abundant BrdU-positive cells in the growing tubular glial regenerate (arrowheads). (E) Late regenerate (day 21 post-injury). en, ectoneural neuroepithelium; hn, hyponeural neuroepithelium.