Figure 2.

Effect of oxygen-glucose deprivation on elements of the neurovascular unit. Stable culture plates (neurons: blue lines; astrocytes: green lines; endothelial cells: red lines) were subjected to OGD for randomly assigned intervals (1 to 16 h) and then assayed for cell viability using MTT (Panel a) or for cell death using LDH release (Panel b). All assays were performed by an investigator blinded to the duration of the OGD. Data represent the mean±SD of 9 wells. In Panel (a), the viability assay showed that the three cellular elements of the neurovascular unit respond quite differently to longer durations of OGD, with neurons being the most vulnerable, followed by endothelial cells, followed by astrocytes. In Panel (b), similar vulnerability profile is confirmed using LDH release. The MTT and LDH results at each time point are statistically significantly different from each other in any given cell type (two-way ANOVA, p < 0.0001, Dunnett's post hoc testing p < 0.001). To kill 80% of cells by 24 h (the LD₈₀) required 2 h OGD for neurons, 6 h for endothelial cells, and more than 10 h for astrocytes.