Fig. 1

Schematic representation of PDGFR-α and Olig2 expressing cells in the GE and CP of FASD and control brains. Semi-quantitative evaluation of PDGFR-α immunoreactive OPCs in the GE displaying a delayed production at 16 WG and an increased density until the physiological disappearance of GE by comparison with control brains (a), as well as in the cortical plate of all FASD brains compared to control brains from 20 WG which persisted until 37 WG (b). Semi-quantitative evaluation of Olig2-expressing OPCs and pre-OLs in the GE in which the density of Olig2 immunoreactive cells was drastically reduced up to 24 WG in FASD brains, followed by an increasing trend to the production/differentiation between 24 and 30 WG (arrows) in FASD brains though the number of OPCs and pre-OLs remained low until regression of GE by 34 WG by comparison with control brains (c). In the cortical plate a lower density of Olig2-expressing cells in all FASD brains was observed regardless of the developmental stage compared with control brains (d). Dotted blue line: control brains; dotted red line: PAE exposed brains; black triangles: second FASD case available at a given stage