Fig. 7.

Effects of GAT927 on HSα4β2 receptors with different numbers of mutant β subunits. (A) The configuration of receptors formed with β2-6-α4 concatamer (Zhou et al., 2003) with or without the β2L15′M mutation. All receptors had the α4:β2 stoichiometry of 2:3, with 0, 1, 2, or 3 mutant β subunits as indicated. All cells were injected on the same day and recorded the same number of days (7) following injection. (B) The average amplitude of the ACh control responses (±S.E.M., n = 5–7). ACh responses of receptors containing two or three mutant subunits were significantly lower than wild-type receptors (P < 0.001 n = 5 to 6). (C) The potentiation of 30 µM ACh responses normalized to the control ACh responses in the same cells. (D) The average (±S.E.M.) amplitude in microamperes of the responses to 30 µM ACh coapplied with 3 µM GAT927 (n = 5–7). While the potentiated responses of all receptors containing any number of mutant β subunits were greater than wild-type receptors (P < 0.001), there were no significant differences among the receptors containing any number of mutant subunits. (E) Average peak current responses in microamperes of cells through the progress of an experiment, where there were first two control ACh applications followed by a coapplication of 30 µM ACh plus 3 µM GAT 927, and then two subsequent ACh applications. (F) Average peak current responses in microamperes of cells through the progress of an experiment, where there were first two control ACh applications followed by an application of 10 µM GAT 927 alone, and then two subsequent ACh applications.