Figure 3.

L9′S mutations in α4, β3 and δ subunits increase GABA sensitivity. (A) GABA concentration–response curves for αβδ, αβδ_m, α_mβδ, αβ_mδ and α_mβδ_m receptors. Data represent the mean ± SEM from n = 5–9. Each data set was fitted to the Hill equation (continuous lines) using a non-linear least-squares method. Parameters from these fits are provided in Table 1. (B) Relationship between the number of mutant receptors incorporated into the receptor pentamer (assuming a stoichiometry of 2α:2β:1δ) and the average GABA EC₅₀ values.