Fig. 4.

Patterns of BrdU labeling in normal and scrambler mouse cortex. A shows large neurons inscm/scm cortex labeled with BrdU at E12 (arrowheads), indicating that the largest cortical neurons (characteristic of layer V), although abnormally positioned, are still among the older neurons in the cortex. In Band C, labeling is illustrated in sagittal sections taken from animals that received BrdU at E16 and were analyzed as adults. B shows +/scm neocortex. Note the neat organization of the labeled neurons at the superficial aspect of the cortex in an area corresponding to layers II/III. Cshows scm/scm neocortex labeled with BrdU on E16. Note the much wider distribution of labeled neurons, with the majority located in the deeper half of the cortex. This observation closely matches results from similar studies inReln^rl/Reln^rlcortex (Caviness, 1982). Scale bars, 100 μm.