Tissue macrophages bridge endothelial tip cells and are present at vascular junctions. Hindbrains from 11.5- and 12.5-dpc wild-type embryos were fluorescently labeled with IB4 (red) and F4/80 (green) to reveal the relationship of endothelial cells (red) and macrophages (double-positive, yellow) in the subventricular zone. (A) A macrophage (arrow) interacts with the filopodia of 2 opposing tip cells (arrowheads) at E11.5. (B) A macrophage embraces a 3-way junction, the product of vessel fusion (curved arrow). (C-D) Snapshots of 3-dimensional models obtained by surface rendering of the confocal z-stacks shown in panels A and B. Panels C′ and D′ show different angles of the models shown in panels C and D, respectively. Scale bar represents 25 μm.