Fig. 6. A signal in postnatal cortical slices and CNTF induce terminal astrocytic differentiation. (A,B) Dissociated E15 GFP cells were cultured over rat E18 or P15 cortical slices for 10 DIV. Examples of E15 GFP+/GFAP+ cells on top of E18 slices (A), and P15 slices (B) that were processed for double immunofluorescence with antibodies directed against GFP (green channel) and GFAP (red channel). The yellow arrowheads show GFP+/GFAP+ astrocytes. (C) Quantification of the differentiated fate of GFP+/MAP-2- cells cultured for 10 days over E18 and P15 cortical slices. Asterisks indicate statistically significant differences (P<0.05) in the percentage of GFP+/GFAP+ cells over P15 slices compared to E18 slices. (D-F) Dissociated E15 GFP cells were cultured over rat E18 cortical slices for 10 DIV in the absence (D) or presence (E) of 50 ng/ml of recombinant CNTF, and then processed for double immunofluorescence with anti-GFP (green channel) and anti-GFAP (red channel) antibodies. (F) Quantification of the differentiated fate of GFP+/MAP-2- cells cultured for 10 days over E18 and P15 cortical slices in the presence of indicated growth factors, expressed as a percentage of the total number of GFP+ cells on top of the slice. Asterisks indicate statistically significant differences (P<0.05) in the percentage of GFP+/GFAP+ cells over E18 slices in the presence of CNTF compared to control (medium) conditions.