Figure 5.

OPC proliferation and differentiation are affected by sleep and wake. A, Left, Double-labeling studies showing a colocalization of PDGFRα⁺ cell (green) and a BrdU⁺ cell in a representative microscopic field from a sleeping animal. Scale bar, 25 μm. Right, Number of PDGFRα⁺/BrdU⁺ cells in S (n = 6 mice), W (n = 6), and SD (n = 6). Values are mean ± SD. *p < 0.05 (Tukey's post hoc test). B, Left, Examples of PDGFRα⁺ cells (green) in S and SD. The framed regions representing two examples of cell doublet are enlarged in B′ and B″; cell nuclei were counterstained with propidium-iodide (blue). Scale bar, 20 μm. Right, PDGFRα⁺ cells forming a doublet in frontal cortex of sleeping (S, n = 6), sleep-deprived (SD, n = 6), spontaneously awake (W, n = 6), and recovering sleep after sleep deprivation (RS, n = 6) mice. Values are mean ± SD. *p < 0.01 (Tukey's post hoc test). **p < 0.001 (Tukey's post hoc test). C, Correlation of the number of PDGFRα⁺/BrdU⁺ cells with duration of REM sleep (r indicates Pearson coefficient). D, Quantitative analysis of PDGFRα⁺ cells in frontal cortex of S (n = 6), SD (n = 6), W (n = 6), and RS (n = 6) mice. Values are mean ± SD. *p < 0.05 (Tukey's post hoc test). Cells forming a doublet are indicated in gray bars. E, Western blotting results from three independent experiments (exp I-III), showing an increase of PDGFRα expression in S relative to SD (n = 12, 4 S, and 4 SD/experiment). Values are mean ± SD. *p < 0.05 (t test). F, Left, Examples of O4⁺ cells (green) in S and SD; cell nuclei were counterstained with propidium-iodide (blue). Arrowheads indicate the cells scored as O4⁺. Scale bar, 20 μm. Right, Relative quantitative analysis of O4⁺ cells in frontal cortex of S (n = 6) and SD (n = 5) mice. Values are mean ± SD. *p < 0.05 (t test).