Extended Data Fig. 7: Dorsal and ventral migratory streams from the Arc target distinct cortical regions in neonatal human and piglet brains.

a, Coronal section of the P0 piglet brain, at the level of the anterior Arc (A-Arc; refer to Extended Data Fig. 3e), immunostained for DCX. (a–d) High magnification images of the boxed areas in a (left) show that DCX⁺ cells migrate out from the Arc to the cingulate cortex (CC (a)), superior frontal gyrus (SFG (b)) and ventral cortex (piriform cortex (PirC) and insula (d)) but less so to the middle frontal gyrus (MFG (c)). Arrows indicate DCX⁺ cells with elongated, migratory morphology. Scale bars, 2 mm (a, left), 100 µm (a,d) and 50 µm (b,c,d1,d2). Gray matter (GM); layer (L); white matter (WM). b, Coronal section of the P0 piglet brain, at the level of the posterior Arc (P-Arc; refer to Extended Data Fig. 6e), immunostained for DCX. (a–c) High magnification images of the boxed areas in b (left). DCX⁺ cells migrate into the posterior CC (a) and temporal cortex (TC (c)). Arrows indicate DCX⁺ cells with elongated, migratory morphology. Scale bars, 2 mm (b, left), 100 µm (a–c) and 25 µm (c1,c2). Caudate nucleus (Cd). c, Coronal section of a term human brain, immunostained for DCX at a plane equivalent to the P-Arc plane of the P0 piglet brain illustrated in b. (a,b) DCX⁺ cells appear individually with an elongated morphology (arrows), migrate into the posterior CC (a) and are densely packed in the dorsal white matter (b). (c) DCX⁺ cells near the ventral Cd exist in clumps. Scale bars, 1 mm (c, left), 50 µm (a–c). d, Spatial mapping of DCX⁺ cells (in green) in serial coronal sections of P0 and a preterm marmoset brain; few DCX⁺ cells (arrows) are present in the dorsal (a) and ventral side (b) of the ventricular wall. Scale bars, 1 mm (map), 30 µm (confocal images). This experiment has been repeated five times (a–d).