Figure 9.
Effects of catalase inhibition on membrane properties and H2O2. a, Current-clamp record showing a reversible membrane hyperpolarization and loss of spontaneous firing in a DA neuron by catalase inhibition with ATZ (1 mm); all DA neurons responded to ATZ (n = 12). b, Simultaneously recorded DCF fluorescence in this cell before (Basal) and during ATZ exposure confirmed H2O2 elevation. Scale bar, 20 μm. c, Time course of H2O2 increase. FI, Fluorescence intensity. d, e, Average time course and amplitude of H2O2 increases induced by ATZ versus those in MCS responders (d; MCSResp) and MCS nonresponders (e; MCSNonresp). Data are means ± SEM. **p < 0.01 and ***p < 0.001 versus MCS. f, Glibenclamide (Glib; 10 μm) reversed ATZ-induced membrane hyperpolarization and loss of cell firing in the continued presence of ATZ (n = 4).