Fig. 4. Effect of time-dependant activation of Notch in Dll1^lacZ/lacZ mutant spheres on neurons and astrocytes. Three-day-old Dll1^lacZ/lacZ mutant spheres were incubated in the presence of J1^EC for various time intervals. as described in the schematic protocol (A). (B) Immunocytological analysis. Spheres were immunostained with antibodies against MAP2 (red), GFAP (green). (C) Quantitative estimation was as described in experimental procedures. Data are representative of three independent experiments. Scale bar: 50 µm. I,II,III and IV indicate the addition of J1^EC, as defined in A.