Figure 6.

Oligodendrocyte and myelin loss after mild respiratory COVID

(A and B) Oligodendrocyte precursor cell (PDGFRα⁺) quantification in the cingulum of the corpus callosum of CD1 strain mice 7 days (n = 5 control, n = 4 mild COVID mice) (A) and 7 weeks (n = 7 mice/group) (B) post-infection (7DPI and 7WPI, respectively).

(C) Representative confocal micrographs of oligodendrocyte precursor cells (PDGFRα, white) in the cingulum of the corpus callosum of mice 7 weeks post-infection. Scale bar, 50 μm.

(D and E) Oligodendrocyte (ASPA⁺) quantification in the cingulum of the corpus callosum of mice 7 days post-infection (n = 5 control, n = 4 mild COVID mice) (D) and 7 weeks post-infection (n = 7 mice/group) (E).

(F) Representative confocal micrographs of oligodendrocytes (ASPA, white) in the cingulum of the corpus callosum of mice 7 weeks post-infection. Scale bars, 50 μm.

(G and H) Quantification of myelinated axons in the cingulum of the corpus callosum of mice 7 days post-infection (G) and 7 weeks post-infection (H) (n = 4 mice/group).

(I) Representative transmission electron microscopy (EM) images at the level of the cingulum of the corpus callosum in cross-section for (G and H). Myelinated axons evident as electron-dense myelin sheaths encircling axons, viewed in cross-section. Scale bars, 2 μm.

(J and K) Comparison to methotrexate chemotherapy-related cognitive impairment model: quantification of myelinated axons in the cingulum of the corpus callosum at 4 weeks post-methotrexate chemotherapy treatment (n = 10 vehicle control, n = 9 MTX-treated mice; J) and 6 months post-methotrexate chemotherapy treatment (n = 7 mice/group; K).

Data shown as mean ± SEM; each dot represents an individual mouse; unpaired, two-tailed t test. p values shown in figure panels. OPCs, oligodendrocyte precursor cells; OLGs, oligodendrocytes; MTX, methotrexate.

See also Figures S7 and Data S1.