Fig. 3. Two different patterns of migration followed by LRN/ECN neurons. Confocal images of whole-mount immunocytochemistry for TAG-1 and Tuj-1 on explants. The pictures on the right illustrate the regions boxed on the diagrams. (A-C) Explants fixed on E12.5. TAG-1 is expressed by superficial transverse fibers (A,C) that are not Tuj-1 positive (B,C). These fibers could coincide with the leading processes of neurons of the superficial migration that are still located at the rhombic lip. (D-F) Explants fixed on E12.5+1DIV. TAG-1 is expressed by the migrating cells emerged by the rhombic lip (D,F). These cells migrate in close contact to each other in an environment void of Tuj-1-positive neuronal fibers (E). The Tuj-1 staining is detected only at the lateral and deeper part of the explant (E,F). (G-L) Explants fixed on E12.5+2DIV. TAG-1-positive cells (G,I) migrating perpendicular to the Tuj-1 positive axonal fibers (H, asterisks in I) are still detected at the lateral part of the explant. Closer to the midline (J-L), TAG-1-positive cells migrate in close contact with neuronal fibers which are Tuj-1 but not TAG-1 positive (arrowheads in L). Scale bars: 50 µm in A-F; 20 µm in G-L.