Figure 1.

Effects of BW284c51 on Ach-induced currents (I_Ach). (a) Chemical structure of BW284c51. (b) Relationship between BW284c51 dose and I_Ach peak amplitude in Xenopus oocytes injected with purified T. marmorata nicotinic AchRs. Repeated I_Ach were evoked by 32 s pulses of 10 μM Ach, either alone (control) or coapplied with increasing concentrations of BW284c51 (BW). The interval between applications was of 10 min. Values obtained for each BW284c51 concentration were normalised as the percentage of the maximum I_Ach response, and data represent the mean±s.e.m. corresponding to five oocytes from three donors. The solid line represents a simple sigmoidal curve that fits to the data with a Hill coefficient close to 1. The inset shows representative, superimposed I_Ach elicited at a holding potential of −60 mV by Ach alone (control) or coapplied with the indicated BW284c51 concentrations to the same oocyte. In this and following figures, downward deflections denote inward currents and the horizontal bars indicate the time of drug application.