Hemin enhances synaptic inhibition in cultured mouse cortical neurons. (A) Spontaneous mIPSCs from an individual neuron in the presence (bottom trace) and absence (top trace) of 5 μM hemin. Scale bar, 25 pA and 1 s. (B) Superimposed mIPSC averages from single neurons (10 events), control (black), and 5 μM hemin (red). Scale bar, 10 pA and 40 ms. (C) mIPSCs are prolonged (τ_w)by 5 μM hemin (▪) (*P < .01). (D) Hemin (▪) increases the amplitude of mIPSCs (*P < .01). (E) Hemin (▪) increases the frequency of mIPSCs (*P < .01). □ indicates control.