As noted above, high-PRS and low-PRS microglial cells showed differential morphological changes and differential gene expression, particularly up-regulation of genes related to phagocytosis, in high-PRS microglial cells following intermittent ethanol exposure. Thus, we hypothesized that high-PRS and low-PRS would show differential phagocytosis after intermittent ethanol exposure. To test this hypothesis, we used pH-sensitive pHrodo zymosan beads to assess the phagocytic activity (55, 56) in microglial cells derived from 18 lines individually, both with high-PRS and low-PRS, after 7-day intermittent ethanol exposure at two different ethanol concentrations (20 and 75 mM; Fig. 7, A and B). At baseline (ethanol-free), we did not observe a significant difference between high-PRS and low-PRS in the integrated density of zymosan beads within the microglial cells (Fig. 7C). However, we did notice a higher proportion of microglia containing beads in low-PRS microglial cells compared to high-PRS microglial cells without ethanol exposure (Fig. 7D). Following intermittent ethanol exposure, we observed significantly augmented phagocytosis in high-PRS microglial cells, particularly at higher ethanol concentrations (75 mM) (Fig. 7, B and C), while low-PRS cells did not exhibit a corresponding
