[Histology and oligodendrogenesis of glial cells].

Oligodendrogenesis is a complex and dynamic phenomenon. Knowledge of the underlying molecular control mechanisms advances steadily, especially in rodents. While the parallelism with human oligodendrogenesis is not fully established, the main characteristics are recognized. Neuroepithelial cells of the neural tube participate in both gliogenesis and neurogenesis. Oligodendrogenesis begins after neurogenesis and stops after birth. It is a focal phenomenon under the control of specific morphogenic proteins, and can generate precursors which are able to proliferate and migrate in the same time. Five steps of oligodendrogliogenesis follow one another acquiring and loosing proteinic markers. They lead to intricated maturation steps for generating myelinizing oligodendrocytes, NG2 cells and precursors of quiescient adult oligodendrocytes.