Fig. 2.

CxV explants mainly grow CST projection axons. a Immunocytochemistry of motor cortex layer V (CxV) explant cultures after 5 days in vitro for markers (red) of neurons (β-III-Tubulin, Tubb3), astrocytes (GFAP), oligodendrocytes (O4), and microglia (Iba1). Nuclei were stained with dapi (blue) and the edge of the explant delineated with white dots. b Distal CxV axons stained for Gad67 (green) and PKCγ (red) showing that the majority of the growing axons arise from CST neurons (green, arrows). c Quantification of the area of PKCy⁺ and Gad67⁺ axons relative to Tubb3 (n = 3 and images, resp.). d, e Immunocytochemistry of CxV (d) and DRG (e) explant cultures from a GFP (green) mouse at 1.6 mm distance from the explants. Axons were stained for GAP-43 (red), a marker for growing axons, and PKCγ (cyan), a marker for CST axons (boxed area enlarged). Scale bars: 25 µm. Statistics: unpaired t-test, p < 0.001