X. laevis oocytes were injected with the indicated cRNA mixtures in a 1:1 ratio (unless otherwise indicated) and subjected to two-electrode voltage-clamp electrophysiology after 2–3 d of incubation time as described in Materials and methods; also see Fig. 1. Data points were fitted to either a monophasic or a biphasic equation with the bottom set to 0 and a Hill slope set to 1 by nonlinear regression. For ACh, biphasic fitting represented the preferred model for all datasets as determined by an F test. Fitted maximal responses of ACh and NS9283 are presented as E_max ± SEM in percentages, with associated potencies presented as pEC₅₀ ± SEM in M for the indicated number of individual oocytes. Observed NS9283 responses at the 31.6-μM concentration are presented as E_{31.6 μM} ± SEM in percentages. The mean maximal current obtained with applications of 3.16 mM ACh is presented as ACh_max current ± SEM in nanoamperes for all tested oocytes for each construct. N/A, not applicable; No pos. pot., no positive potentiation; Inconclusive, meaningful fitting not possible, as only ∼50% of the oocytes displayed a positive NS9283 response.