Fig. 8

Newly generated oligodendrocytes preferentially target axons with higher levels of activity. a Representative images of the corpus callosum of PdgfRα-CreERT²: Tau-mGFP mice that had undergone 1 week of treatment with either CNO or saline. Coronal sections were immunolabeled with mature oligodendrocyte marker CC1 (magenta) and GFP (green); insets show a higher number of doubly labeled GFP⁺/CC1⁺ cells in CNO-treated mice (bottom inset) compared to saline controls (top inset). b, c Quantification of the density of GFP⁺ cells (b) and the density of CC1⁺/GFP⁺ cells (c) in the corpus callosum of CNO- or saline-treated mice. d, e Quantification of the percentage of all CC1⁺ cells that were GFP⁺ (d) and the total density of CC1⁺ cells (e) in stimulated and non-stimulated mice. f Representative images of newly differentiated cortical oligodendrocytes, demonstrating colocalization with PAN-NF⁺ or mCherry⁺ axons. g Analysis of the total number of internodes per oligodendrocyte. h Quantification of the number of internodes that were ensheathing PAN-NF⁺ or mCherry⁺ axons in each condition. i The total cortical area occupied by either PAN-NF⁺ or mCherry⁺ processes was similar in both CNO- and saline-treated mice. j The percentage of all internodes per oligodendrocytes that ensheathed mCherry⁺ axons was higher in CNO-treated mice compared to saline controls. Welch’s corrected unpaired two-tailed t-test: ***P < 0.001, **P < 0.01, *P < 0.05; n = 4 mice/condition, ± s.e.m. Scale bars = 200 µm (a), 40 µm (insets), 20 µm (f)