Figure 5.

Mean open duration of single-channel currents was reduced for α4β2δ receptors containing pure variant δ subunits. A1–C1, Examples of single-channel currents evoked by 1 mm GABA from wild-type α4β2δ, and pure variant α4β2δ(E177A) and α4β2δ(R220H) receptors are presented. The single-channel current open duration was longer for the wild-type α4β2δ receptor than for variant α4β2δ(E177A) or α4β2δ(R220H) receptor. A2–C2, The distributions of open states of the wild-type α4β2δ, and variant α4β2δ(E177A) and α4β2δ(R220H) receptors were plotted. There were 4387 open events used for A2, 2331 open events for B2, and 2931 open events for C2. Each histogram contained data from a single patch. D, The single-channel current mean open duration was decreased for variant α4β2δ(E177A) (n = 7) and α4β2δ(R220H) receptors (n = 8) compared with wild-type α4β2δ receptors (n = 14). E, Comparison of the mean value of τ₁, τ₂, and τ₃ among wild-type α4β2δ and variant α4β2δ(E177A) and α4β2δ(R220H) receptors. F, Comparison of the mean A₁, A₂, and A₃ among wild-type α4β2δ and variant α4β2δ(E177A) and α4β2δ(R220H) receptors. The average open events used for each patch were 2559, 2414, and 2921 for wild-type α4β2δ, variant α4β2δ(E177A), and α4β2δ(R220H) receptors, respectively. wt, Wild-type α4β2δ receptors. The error bars represent SEM. Asterisks indicate significant difference from wild-type α4β2δ receptor (*p < 0.05, **p < 0.01, and ***p < 0.001).