Figure 3. Axonal development, targeting, and organization of newborn granule cells in the adult mouse hippocampus. A, Horizontal view of sample traced axons from 10, 17, 21, 35, 56, and 77 dpi. Scale bar, 100 μm. B, Primary axon length of newborn granule neurons at different times after labeling. Open orange circles represent data from individual GFP+ neurons examined. Numbers associated with open circles indicate total number of GFP+ neurons examined for each condition. Values representing mean ± SEM are also shown (●; *p < 0.01; #p = 0.12; one-way ANOVA, F(5,70) = 61.92, p ≈ 0). C, Representative tracings of three adult-born granule cells with temporal (a), center (b), and septal (c) relative positions. Arrows highlight sharp turn of more laterally positioned granule cells. D, Coronal view and illustration of axon organization among adult-born granule cells in C along the septo-temporal axis: (i) horizontal view illustrating axon stacking and staggering of termination points; (ii) coronal view illustrating graded axon hilar turns. T, temporal; S, septal; D, dorsal; V, ventral.