PMC

Caspase-3 cleavage in SGZ (A) and SVZ (B) from control (A Top; B Left) and VEGF-treated (A Bottom; B Right) rat brains in vivo. Brain sections through SGZ were stained with an antibody against the 17 to 20-kDa cleavage product of caspase-3. (Original magnification, 4×; high-power views, 20×.) Data are representative fields from at least three experiments per panel.

Association of VEGF-stimulated BrdUrd incorporation with VEGFR2/Flk-1 receptors in murine cortical cultures in vitro. (A) Immunocolocalization of VEGFR2/Flk-1 (green, Top) but not VEGFR1/Flt-1 (green, Bottom) receptors with BrdUrd labeling (red). (Original magnification, 40×.) (B) Inhibition of VEGF (10 ng/ml for 24 h)-stimulated BrdUrd incorporation into cortical cultures by the VEGFR2/Flk-1 receptor tyrosine kinase inhibitor SU1498. Data are representative fields (A) or mean values ±SEM (B) from at least three experiments per panel.

VEGF receptor expression in neuroproliferative zones of rat brain in vivo. Brain sections through SVZ (A and B) and SGZ (C and D) were stained with antibodies against VEGFR2/Flk-1 (A and C) and VEGFR1/Flt-1 (B and D). (Original magnification, 4×.) VEGFR2/Flk-1, but not VEGFR1/Flt-1, immunostaining was observed in SVZ and SGZ (arrows), as well as in ependymal cells (ciliated cells at far left in A). VEGFR2/Flk-1 expression (green) was colocalized with Dcx (red) in SGZ (E) and SVZ (F). Data are representative fields from at least three experiments per panel.

VEGF stimulates BrdUrd incorporation into neuroproliferative zones of rat brain in vivo. aCSF (Left) or 10 μg/ml of VEGF (Right) was infused i.c.v. at 1 μl/h and BrdUrd 5′-monophosphate (50 mg/kg) was given i.p. twice daily for 3 days. Four days later, BrdUrd was localized by immunohistochemistry in hippocampus (A) and rostral SVZ (B) (Original magnification, 4×; high-power views of SVZ, 20×). Note that BrdUrd incorporation is not confined to neuroproliferative zones, but extends, for example, into the dentate hilus in (A) consistent with the labeling of both neuronal and non-neuronal (e.g., astroglial) cells (see Fig. ). Data are representative fields from at least three experiments per panel.

VEGF stimulates BrdUrd incorporation in murine cortical cultures in vitro. (A) Immunodetection of BrdUrd labeling (red) in control (Left), and 10 ng/ml VEGF-treated (Right) cortical cultures at 24 h in vitro. (Original magnification, 20×; Insets, 40×.) (B) Quantification of VEGF-stimulated BrdUrd incorporation by ELISA, expressed as a percentage of BrdUrd incorporation in control cultures. (C) Cell counts (number of DAPI-stained nuclei) in VEGF-treated cultures, expressed as a percentage of cell counts in control cultures. (D) Colocalization of BrdUrd labeling (red) with immunoreactivity for the immature neuronal marker ENCAM (green, Left) and the neuroepithelial precursor cell marker nestin (green, Right). Data are representative fields (A and D) or mean values ± SEM (B and C) from at least three experiments per panel.

VEGF stimulates incorporation of BrdUrd into neurons, astrocytes, and endothelial cells in vivo. Rats were given VEGF and BrdUrd as described in the legend to Fig. . Brain sections through SGZ (A) and SVZ (B) were stained with antibodies against the immature neuronal marker Dcx (green) and against BrdUrd (red). (C) Sections were stained with antibodies against BrdUrd (purple) and either the mature neuronal marker NeuN (Left), the astroglial marker GFAP (Center), or the endothelial cell marker vWF (Right; brown). Note that BrdUrd and NeuN are nuclear markers, whereas Dcx, GFAP, and vWF are extranuclear. In C Left, all cells shown stain for NeuN, and all except the cell at far left also stain for BrdUrd. In C Center, a single cell is seen, with GFAP-positive processes and BrdUrd-positive nucleus. In C Right, the vessel running diagonally from top left to bottom right stains for vWF, and the four associated nuclei stain for BrdUrd. Data are representative fields from at least three experiments per panel.