Fig. 6. The effect of norepinephrine on the amplitude distributions of mIPSCs. Amplitude histograms of GABAergic (A ) and glycinergic (C ) mIPSCs before and during application of norepinephrine (NE). Each histogram was constructed from continuous recording for 120 s. (A ) There were 183 and 761 events analyzed before and during application of norepinephrine (10 μM). Norepinephrine increased the frequency from 1.53 Hz to 6.34 Hz. Median amplitudes before and during norepinephrine application were 7.4 pA and 9.0 pA, respectively. (C ) There were 178 and 645 events analyzed before and during application of norepinephrine (60 μM). Norepinephrine increased the frequency from 1.48 to 5.38 Hz. Median amplitudes before and during norepinephrine application were 8.9 and 10.8 pA, respectively. (B , D ) Cumulative histograms of GABAergic (B ) and glycinergic (D ) mIPSCs. Norepinephrine significantly shifted the curves to the right for both GABAergic and glycinergic mIPSCs (Kolmogorov–Smirnov test, P < 0.005 for B , P < 0.01 for D ).