Fig. 2: Newborn neuroblasts migrate in a radial-like fashion in the adult NAc.

a Coronal brain section of a P65 wild-type mouse. DCX+/PSA-NCAM+ neuroblasts exhibit a density gradient from the ventral V-SVZ to the NAc. a1 High-resolution image from the area indicated with the yellow dashed rectangle in a. a2 High-magnification (×63) image from the area indicated with the yellow dashed rectangle in a1. Left, maximum-projection image showing GFAP+ fibers paralleling DCX+ neuroblasts. Right: single-plane detailed image and orthogonal views showing direct contacts between glial fibers and neuroblasts. b High-magnification image showing DCX+/PSA-NCAM+ neuroblasts aligned with GFAP+ glial fibers in P65 wild-type mice. c The Euclidean distance between DCX+ neuroblasts and the closest GFAP+ glial fiber in the NAc is shorter than that of a randomly established grid and glial fibers (***p < 0.0001; Mann–Whitney test; median ± IQR). d The direction of migrating neuroblasts strongly correlates with the direction of glial fibers in the NAc of 8-week-old wild-type mice. Each dot indicates single DCX+ neuroblasts (magenta) or GFAP+ glial fibers (green). Continuous lines represent the average distribution for both groups considering the Euclidean distance and the angle from the ventral corner of the V-SVZ. e Relative distribution of DCX+ neuroblasts (magenta) and GFAP+ (green) fibers at four rostro-caudal levels of the NAc (**p < 0.01; ****p < 0.0001; two-way ANOVA with Bonferroni’s multiple comparison post hoc test; mean ± SD). f PSA-NCAM+ neuroblasts migrate following Collagen IV+ blood vessels in the NAc. g Pseudo-colored TEM images showing chains of neuroblasts (A) surrounded by an astrocyte (B) that also establishes contact with a blood vessel (BV). Abbreviations: ac, anterior commissure; lv, lateral ventricle; NAc, nucleus accumbens. Scale bars in µm: 100 (a), 25 (a1), 5 (a2, b, f, g), 1 (g1, g2). See Supplementary Figs. 3–6 and Supplementary Movies 2 and 4.