Figure 4. ACh gates larger macroscopic currents characterized by a greater proportion of α-BgTx-sensitive nAChRs in α5 minus neurones compared with control.

A, representative macroscopic currents evoked by 500 μM ACh in control vs.α5 minus neurones are shown. Macroscopic currents evoked by ACh included only a small α-BgTx-sensitive component, as the amplitudes of currents elicited by maximal concentrations of ACh were not significantly affected by α-BgTx in native sympathetic neurones (see also Fig. 1 of the accompanying paper, Yu & Role, 1998). In contrast, α-BgTx significantly decreased the peak as well as increased the rate of decay of ACh-elicited currents in α5 minus neurones. B, the peak amplitude of the many such currents recorded (numbers shown on top of each box) under the conditions detailed are shown as box plots for comparison. The effect of α-BgTx on the amplitude of ACh-evoked currents in α5 minus neurones is statistically significantly (P≤ 0.013).