Migration of granule cells. Immunofluorescent detection of 5-bromodyoxyuridine (BrdU; red) and neuronal nuclear protein (NeuN; green) in cerebella of control (A-C) and nestin-Cre/DG-null (D-F) mice at P16. Quantitative analysis of GC migration from P8 to P16 (G). Representative schematic of lobules IV-V and IX from a control (H, J) and nestin-Cre/DG-null (I, K). GC from the EGL proliferate, differentiate and migrate inward to form the GCL. In the nestin-Cre/DG-null mice, some of these cells undergo differentiation but remain at the cerebellar surface or locate within fissures instead of migrating to their proper destination in the IGL. The surface of lobule IV-V is not affected in the nestin-Cre/DG-null cerebellum. Asterisks (*) indicate ectopic GCs (D-F). Error bars denote standard error of the mean. Asterisks in the graph denote P < 0.05. n = 3 for each group described in bar graphs. GC = granule cell; GCL = granule cell layer; IGL = internal granule cell layer. Scale bar: 20 μm.