Figure 9. Ultrastructure of an Ependyma-Derived Oligodendrocyte.

Electron micrograph of an ependyma-derived β-gal–expressing cell in the nuclear plane 10 mo after injury (nucleus labeled with asterisk in [A]). (A) The cell displays ultrastructural characteristics of a mature oligodendrocyte such as a denser cytoplasm with fewer intermediate filaments than that of a neighboring astrocyte (As), (B) tight junctions (tj) between the cell body, and an oligodendrocyte process of another cell and (C) granular endoplasmic reticulum (er) cycternae in the perikaryon. Ax, axon; f, filamentous matrix.

(D) A process (p) of the cell adjacent to the myelin sheath on an axon.

Scale bars indicate 1 μm in (A) and 250 nm in (C) and (D).