Figure 1.

Experimental procedures and labeled cells. The animals were lightly fixed with paraformaldehyde, and the brain was removed, trimmed and flattened, and sliced at 250 μm tangentially to the cortical surface (A). Slices were incubated in DAPI solution to visualize nuclei of neurons (B). Layer 3 pyramidal cells were individually injected with Lucifer yellow (C) and reacted for DAB product (D). Examples of injected cells from V1, TE, and PFC of a 3-week-old monkey are shown in E, F, and G, respectively. Scale bars: 20 μm (B–D), 100 μm (E–G).