Fig. 6

Oligodendrocytes have IL-4 receptors and exhibit decreased differentiation when treated in vitro with IL-4. a Sections of normal rat brain at the level of the corpus callosum were double stained with antibody to IL-4 receptor (IL-4R) and CC-1, with DAPI as a nuclear marker. b Rat oligodendrocyte progenitors were grown in culture and treated with increasing concentrations of IL-4 at time of differentiation. Staining for GalC, a marker of both immature and mature oligodendrocytes was performed after 72 h and shows a dose-dependent decrease in GalC+ cells. DAPI, blue; GalC, green. Size bar = 30 μm. c Quantification of percent differentiation, GalC+ cells relative to DAPI+ nuclei, in rat OPCs treated with IL-4 and control (n = 3 biological replicates). *Significant difference versus control (1 ng/ml: P = 0.100, 10 ng/ml: P = 0.013, 50 ng/ml: P = 0.023), two-tailed T test