As the majority of native GABAA receptors are believed to be composed of two α, two β and single γ or δ subunits (Chang et al. 1996; Farrar et al. 1999; Quirk et al. 1995) we did additional comparisons in cells expressing 2:2:1 ratios and increased or decreased the α2 abundance However, increasing the ratio of α2 mRNA above the baseline of a 2:2:1 ratio led to decreased GABA currents (Figure 2A). Increasing the α2 or γ3 subunits may alter the formation of functional channels bi-directionally by changing receptor assembly or membrane trafficking (Kittler, McAinsh, and Moss 2002). Overall our study indicates that small changes in the relative abundance of subunit mRNA injected affect GABAA receptor current amplitude.
