We also studied early cell orientation by co-electroporating brains with a construct encoding the Golgi resident enzyme Gal-T2 tagged with yellow fluorescent protein (YFP) (Gal-T2-YFP) plus DsRed, in control and shRNA-IGF-1R conditions. The results of these experiments showed that, in control brains, the Golgi complex of over 75% of the DsRed positive cells were oriented towards the marginal zone (Fig. 5a left). In contrast, only 60% of the shRNA-IGF-1R electroporated cells exhibited the Golgi complex oriented toward the outer cortical plate, showing a close to random arrangement (Fig. 5a and b). For quantifications, we considered that a cells has the Golgi not oriented to the cortical plate when the majority of the staining was concentrated in the lower part of the axis as shown in the diagram (Fig. 5c). These experiments indicate that in the absence of IGF-1R neurons fail to maintain or acquire proper orientation.Figure 5shRNA-IGF-1R disrupts the polarized location of migrating neurons. (a) Co-electroporation of shIGF-1R/DsRed and GalT2-YFP into brains at E15 (left) decreases the proportion of DsRed-positive cells in the VZ and/or IZ with a Golgi apparatus oriented towards the radial axe fate at E17 compared to a control vector (left). Lower magnification pictures (bottom) and higher magnification insets (top) are shown. Calibration bar = 50 μm (bottom) or 25 μm (top). (b) Quantification of the experiment shown in A. Student’s t test; **p-value = 0.01. Note that in the brains suppressed for IGF-1R the number of cells facing the cortical plate is close to 60% (random distribution = 50%). n = 3 independent experiments. An average of 300 cells was scored for each condition. (c) For quantifications, we considered that a cell has the Golgi not oriented to the CP when the majority of the GalT2 staining was concentrated below the axis.