Fig. 6. Retinol stimulates SVZ neurogenesis in explants. (A-D) BrdU immunolabeling of SVZ cells (arrows) in slices incubated with vehicle (Veh; A), retinol (Ro; B), disulfiram (Ds, C), or Ds and Ro (D). Explants were treated for 2 days, exposed to BrdU for 2 hours before fixation, and then resectioned at 40 µm. Note the increased BrdU labeling in the Ro-treated slice (B) compared with vehicle (A) or Ds (C), and the lack of increased BrdU-positive cells in the explant cultured with both Ro and Ds (D). E-H: Confocal images of explants treated as in A-D and immunostained with an anti-calretinin antibody. Ro treatment (F) expanded the RMS (arrows) compared with the other groups, and the effect was blocked by co-treatment with Ds (H). I: Quantification of BrdU-positive cell numbers per fixed SVZ area (see Fig. 4C). ^**Denotes P<0.01. CTX: cortex. RMS: rostral migratory stream. OB: olfactory bulb. Scale bar: 100 µm.