Reelin-induced radial glial phenotype is dependent on γ-secretase activity. HNPCs were deprived of FGF and EGF for 24 hours prior to their transfection or treatment. a, g, HNPCs were transfected with empty vector or d, jNICD for 24 hours before fixation. The percentage of the BLBP-positive radial glia increased from 2.3% in the empty vector transfected cells to 6.2% in the NICD transfected cells, *p-value = 0.05. b, h,HNPCs were treated with partially purified control or c, i,partially purified Reelin for 24 hours before fixation. The percentage of the BLBP-positive radial glia increased from 3.4 % in the control-treated cells to 9.5% in the Reelin-treated cells, **p-value = 0.05. e, k, f, l, 10 μM of L-685,458 was used to inhibit the activity of γ-secretase for 24 hours in the control and the Reelin treated HNPCs. γ-secretase inhibition in the Reelin treated cells abolished Reelin's effect by reducing the percentage of the BLBP-positive radial glia back to 1.6 %, ***p-value = 0.05. The results represent the standard error of the mean ± SEM of at least three independent experiments. One-way ANOVA with Tukey's post hoc test for individual treatment differences was used for statistical analysis. Values that are significantly different from each other according to Tukey's test are indicated by asterisks. Scale bar for a-f is 100 μm and for g-l is 50 μm.