Skip to main content
. 2008 Sep 11;105(38):14662–14667. doi: 10.1073/pnas.0805640105

Fig. 1.

Fig. 1.

Temporal regulation of oligodendrocyte differentiation. (A) Immunostaining in rat spinal cord sections from E10 through P20. OPCs, identified by immunostaining for PDGFRα, appear initially at E15 and then proliferate as they migrate throughout the spinal cord. (B) Immunostaining in rat spinal cord sections from P0 through P10. Astrocytes (blue) are identified by immunostaining for GFAP. Oligodendroyctes (red), identified by immunostaining for MBP, do not appear in the spinal cord until P5, almost two weeks after the initial appearance of OPCs. (C and D) Western blot analysis of rat spinal cords (C) and OPC-DRG cocultures (D) probed for proteins expressed by OPCs (NG2), oligodendrocytes (MBP), and astrocytes (GFAP). Actin serves as a loading control. Cocultures replicate the temporal expression pattern seen in vivo, in which the appearance of oligodendrocytes is delayed compared with the appearance of OPCs. (E) In OPC-DRG cocultures, immunostaining for MBP labels differentiated oligodendrocytes (red). Nuclei are stained using DAPI (blue). Differentiation begins 10 days after a standard density of 200,000 OPCs is seeded onto neurons. After 15 days, a robust and reproducible amount of myelination is observed. The onset of differentiation is preceded by a period of OPC proliferation, a pattern that approximates the behavior of OPCs in the spinal cord. (F–H) Immunostaining and Western blot analysis of OPC-DRG cocultures, in which OPCs are seeded at low density (20,000 OPCs) (F), standard density (200,000 OPCs) (G), and high density (2 million OPCs) (H) onto DRG neurons. Immunostaining for MBP labels differentiated oligodendrocytes (red). Nuclei are stained by using DAPI (blue). Western blot analysis of cocultures are probed for proteins expressed by OPCs (PDGFRα), oligodendrocytes (MBP), and astrocytes (GFAP). Actin serves as a loading control. These results demonstrate that an increase in cell density accelerates the onset of oligodendrocyte differentiation, but does not affect the differentiation of OPCs into astrocytes.

HHS Vulnerability Disclosure