Figure 2.

H₂O₂ (200 μm) selectively increases the evoked baseline fEPSP slope in TRPM2^−/− neurons. Field potentials (fEPSP) evoked via stimulation in the Schaffer collaterals (at 100–200 μA) were recorded in the hippocampal CA1 region in slices from TRPM2^−/− and WT mice under control (ACSF) and oxidative (ACSF+ 200 μm H₂O₂) conditions. H₂O₂ was administered through bath application. A, B, Both WT and TRPM2^−/− had similar raw fEPSP slope during baseline recordings (black bar); and during H₂O₂ exposure (gray bar), TRPM2^−/− slices showed a 49.0 ± 3.4% increase in fEPSP slope: *p < 0.05. Representative fEPSP recordings (A) using gray and black to represent with and without H₂O₂, respectively, showed this effect in TRPM2^−/−. C, A longer application of H₂O₂ caused fEPSP to increase in TRPM2^−/− (n = 7; gray) for as long as it is applied (60 min), without any effect in WT (n = 5; black). D, The H₂O₂-induced increase in fEPSP in TRPM2^−/− (gray; n = 8) was found to be reversible when application of 200 μm H₂O₂ (white bar) was removed, with no effect on WT (black; n = 8).