Figure 1.

Inhibition of MA currents by the styryl dyes FM1-43 and FM3-25. (A) Concentration-inhibition functions for FM1-43 for inhibition of 3 classes of MA currents (each data point, n = 3–10). FM1-43 inhibited SA currents (Caps- neurons) at lower concentrations than RA currents in either Caps- or Caps+ neurons (2-way ANOVA, P < 0.001). At 0.6 μM FM1-43 had a slight facilitatory effect on currents. (B) Example traces showing inhibition of 3 classes of MA currents by 2, 6 and 15 μM FM1-43. (C) Inhibition of a RA current (Caps- neuron) by 5 μM FM3-25. All vertical scale bars: 0.2 nA. Horizontal scale bars: (B) 50 msec, (C) 100 msec.