Fig. 5.

WT virus increases BBB permeability while WT, Alpha, Delta, Eta and Omicron infections modulate extracellular glutamate. BBB were infected at MOI 1 (full lines) or MOI 0.1 (dashed lines) with WT (blue), Alpha (pink), Beta (green), Delta (brown), Eta (orange) or Omicron (yellow-green) viruses and we measured A BBB permeability (dextran-rhodamine assay) and B extracellular glutamate at 2, 4 or 6 days post-infection. An empty control insert (grey) was used to estimate the passive diffusion of dextran-rhodamine from the upper chamber to the collector and the concentration of glutamate in the BBB medium over time. Data are presented in raw data (i.e. concentration of Dextran-rhodamine B 70 kDa in µg/mL or concentration of glutamate in µM). The mean and SEM for 3 to 4 different experiments are shown. Asterisks denote statistically significant data as defined by one-way analysis of variance (ANOVA) with corrections for multiple comparisons (Tukey) (*P < 0.05, **P < 0.01)