Figure 2.

NG2⁺ cells and MBP⁺ oligodendrocytes grown on DRG axons in culture. DRG axons grown in culture for 3 weeks were immunostained for neurofilament (red) to identify axons and DAPI (blue) to label cell nuclei. (A) Immature oligodendrocyte progenitor cells (OPCs) were plated onto DRG axons and immunostained for the immature OPC marker NG2 (green) after 2 days in co-culture. NG2⁺ positive OPCs have differentiated into multipolar cells with many processes contacting multiple axons in order to initiate the myelination process. (B) OPCs grown in co-culture with DRG axons for 7 days were immunostained with myelin basic protein (MBP), a component of the myelin sheath. Immature OPCs have differentiated into a myelination phenotype with expression of MBP and the formation of multiple segments of compact myelin associated with the axons. Scale bar = 15 μm.