Figure 2.

NRG1 depolarizes action potential threshold. A–D, Representative traces of a single AP evoked from a suprathreshold current injection (left) and corresponding phase plots (dV/dt vs V_m; right) measured at baseline (black), and following 10 min (gray) and 20 min (red) of treatment. Inset magnifies threshold in E⁺N phase plot. Calibration: 2 mV, 10 mV/s. E, Summary graph for normalized AP threshold, as determined by d³V/dt³ plots, at 20 min (E⁺N, n = 5; E⁻N, n = 5; E⁺V, n = 5; E⁺NPD, n = 6). **p < 0.005 comparing E⁺N to E⁺NPD; ^#p < 0.05 comparing E⁺N to E⁻N and E⁺V.