Figure 4.

ACh concentration-response studies of zebrafish nAChR expressed in Xenopus oocytes. Data were obtained by alternating applications of ACh at fixed control concentrations (see Methods) and ACh at increasing concentrations. The control responses were relatively consistent throughout the entire range of test concentrations. Test responses were initially normalized relative to the ACh controls, and the data are expressed relative to the observed ACh maximum responses. Data plotted are for the peak currents of the heteromeric receptors and for α7 net charge. Each point is the average ± SEM of responses from at least four oocytes. The solid curves represent fits of the Hill equation to the data, and that parameters for the fits are in Table 2.