Figure 1.

Cerebral Glycogen Is Substantially Increased in Human, Primate, Rodent, and Cultured Astrocytes at the Onset of Reperfusion

(A) A representative diagram showing the core infarct and penumbral regions in the ipsilateral hemisphere after I/R onset (top). Glycogen accumulated in the ischemic penumbra of the ipsilateral hemisphere compared with the contralateral hemisphere in humans (n = 4, paired samples ttest), monkeys (n = 6, paired samples ttest, at 12 h after reperfusion), and mice (n = 8, paired samples ttest, at 12 h after reperfusion) after reperfusion, as indicated by PAS staining. The glycogen levels in the ischemic penumbra of the ipsilateral hemisphere and the homologous contralateral hemisphere were quantified with a biochemical assay. The arrows indicate glycogen-positive cells. Scale bars represent 50 μm.

(B) Increased glycogen in cultured astrocytes, as revealed by PAS staining and a biochemical assay at 12 h after reoxygenation (n = 8, independent ttest). The arrows indicate glycogen-positive cells. Scale bars represent 100 μm.

(C) Excessively elevated glycogen was localized in astrocytes but not neurons at 12 h after reperfusion in the mouse brain, as revealed using electron microscopy. The arrows indicate glycogen granules. Nu represents the nucleus. Cyto represents the cytoplasm. The blue dashed lines represent nuclear membranes, and the red dashed lines represent cell membranes. Scale bars represent 1 μm.

The data are presented as the mean ± SEM. ^∗∗p < 0.01, ^∗∗∗p < 0.001. See also Table S1 and Figures S1 and S14.