Inner and outer fiber layers are not apparent in macaque cortical areas rostral to the occipital lobe.

<p>(<b>a</b>) Nissl stained coronal section of E80 macaque frontal lobe at the level of the genu of the corpus callosum (CC). (<b>b–c</b>) An adjacent section taken from the E80 macaque frontal lobe stained with DAPI (blue) and Tbr2 (red). (<b>b</b>) DAPI staining highlights the different cell densities within the inner subventricular zone (iSVZ) and outer SVZ (oSVZ). The cell dense region surrounding the lateral ventricle includes the very thin ventricular zone and the iSVZ. Tangential streams of cells can be visualized within the oSVZ in DAPI staining. Inner and outer fiber layers are not apparent. (<b>c</b>) The same section showing Tbr2 (red) and DAPI. As in visual cortex, the dense inner band of Tbr2 cells corresponds to the iSVZ and the diffuse outer band of Tbr2+ cells corresponds to the oSVZ. Scale bar in (<b>c</b>) applies to (<b>b</b>). IC, internal capsule.