Figure 1.

Mechanisms by which alcohol use during pregnancy might cause dysmyelination in fetal brain.

In brains of EtOH-exposed fetuses, studies of OL stage-specific biomarkers show a shift away from mature oligodendrocytes (OL) toward immature OL and OL precursor cells (OPC). But the absolute numbers of cells at each phase of OL development is reduced, and the proportions of OPCs and OLs showing caspase-3 activity is increased. Thus, EtOH itself, or its metabolite, acetaldehyde, can inhibit proliferation of OPC, as well as inhibit the differentiation of OPC to immature OL, or the maturation of immature OL to OL. Each of these effects may be due at least in part by increased apoptosis at each developmental stage. MBP: Myelin basic protein: OL: oligodendrocytes: OPC: oligodendrocyte precursor cells.