Figure 4. Stimulation of NHE-1 activity in microglia after OGD/REOX. A, Representative traces of pHi during the NH4+/NH3 prepulse in M4T.4 microglia after 2 h OGD and 60 min REOX. In the HOE 642 experiments, the drug was present only during 60 min REOX. Red line, pHi recovery rate in OGD/REOX control cells. Blue line, pHi recovery rate in OGD/REOX plus HOE 642-treated cells. Con, Control. B, Summary of pHi in M4T.4 microglia. In the drug treatment experiments, HOE 642 (1 μm), EIPA (100 μm), bafilomycin (1 μm), or DPI (1 μm) was present during REOX only. C, pHi recovery rate after NH4+/NH3 prepulse in M4T.4 microglia. Data are mean ± SEM. n = 3–10. *p < 0.05 versus control; #p < 0.05 versus OGD/REOX. D, Representative traces of pHi recovery in primary microglia after 2 h OGD and 60 min REOX. E, pHi recovery in primary microglia when NHE-1 activity was inhibited. The HOE 642 (1.0 μm) was only present during 60 min REOX. F, pHi changes in primary microglia. G, pHi regulation in primary microglia after the NH4+/NH3 prepulse. Data are mean ± SEM. n = 3–5. *p < 0.05 versus control; #p < 0.05 versus untreated .