Neuronal migration errors are not spatially uniform. GC migration errors discerned from H&E-stained paraffin sections of nestin-Cre/DG-null and GFAP-Cre/DG-null cerebella (see Figure 3 and Additional file 6: Table S1) were plotted in mid-sagittal maps (A). Darker shading reflects a higher proportion of samples displaying pathology in a specific region of the cerebellum. Nestin-Cre/DG-null cerebella display more widespread clusters of ectopic GC. The surface of lobules IV-V, and an area on the surface of lobule VI, are relatively spared. A surface map of GC migration errors from a representative nestin-Cre/DG-null cerebellum at P8 is illustrated (B). Pathologic clusters of non-migrating GC exist over a vast area of lobule surfaces and fissures at every parasagittal level examined.