Fig. 4. Cellular interactions of MGE-derived tangentially migrating neurons. (A,B) Relationship between the leading process of E14 GE-GFP cells and the radial glial fibers in the intermediate zone (red, nestin). Cells migrating tangentially in the intermediate zone make several contacts with radial glial fibers, whereas some of the cells invading the cortical plate that migrate radially (arrow in A, shown at higher magnification in B) make multiple close contacts with the nestin+ glial fibers (arrowheads in B). In each image, the dorsal (D) and lateral (L) aspects are indicated. (C) Example of a migrating E14 GE-GFP cell making a few close contacts with axons (red, neurofilament 165 kDa) within the cortical intermediate zone. The insets numbered 1 (red, NF 165 kDa), 2 (green, GFP) and 3 (1 and 2 merged) represent a X-Z orthogonal section taken at the level indicated by the arrowhead in C. The blue arrows (3) indicate the location of close contact between an axon (red) and the leading process (green) of the tangentially migrating cell shown in C. (D) Example of an E14 GE-GFP cell migrating radially in the cortical plate towards the pia. This GE-GFP neuron makes contacts with cortical apical dendrites, revealed by MAP2 immunofluorescence (red). The insets numbered 1 (red, MAP 2), 2 (green, GFP) and 3 (1 and 2 merged) represent a X-Z orthogonal section taken at the level indicated by the arrowhead in D. The blue arrows (3) indicate the location of a close contact between an apical dendrite and the leading process of the GFP+ cell shown in D. Scale bars: 80 µm in A; 20 µm in B,C; 30 µm in D.
