Fig. 3.
The effect of isoflurane (Iso) exposure and rapamycin treatment on oligodendrocyte development in fimbria. (A) Oligodendrocyte progenitor cell proliferation was detected with 5-bromo-2’-deoxyuridine and neural/glial antigen 2 double-immunolabeling. A reduction in 5-bromo-2’-deoxyuridine–positive/neural/glial antigen 2–positive cells in isoflurane-exposed animals was observed compared to the control. This number was increased in isoflurane plus rapamycin injection group. Scale bar = 20 μm. (B) Western blot data indicated that the neural/glial antigen 2 level was not altered by isoflurane exposure and rapamycin administration. Expression of NK2 homeobox 2, a transcript factor for oligodendrocyte differentiation, was downregulated by isoflurane, and rapamycin treatment attenuated this effect. (C) Oligodendrocyte differentiation was analyzed with lineage tracing using immunohistochemistry. The ratio of adenomatous polyposis coli–positive mature oligodendrocyte number over platelet-derived growth factor receptor alpha–positive oligodendrocyte progenitor cells in isoflurane-exposed mice revealed reduction compared to control, and rapamycin treatment increases the ratio. Scale bar = 20 μm. n = 8 for each group; one-way ANOVA; *P < 0.05; **P < 0.01; ns, no significance. Error bars: SD. APC, adenomatous polyposis coli; PDGFR-α, platelet-derived growth factor α.