Figure 10.

Charge reversal at α₁ Lys¹⁰⁴ and γ₂ Asp⁷⁵ does not rescue GABA sensitivity or benzodiazepine responses to WT responses. A, the α₁(K104D)β₂γ₂(D75K) receptor GABA concentration-response curve is significantly right-shifted compared with WT receptors (F(8,105) = 2.8, p < 0.01). The EC₅₀ for WT receptors was 86.8 ± 16.5 μm, increasing to 146.3 ± 23.1 μm for the α₁(K104D)β₂γ₂(D75K) GABA_AR. Each symbol represents the mean from five to six oocytes, and error bars represent the S.E. B, bar graph comparing levels of benzodiazepine enhancement between α₁(K104D)β₂γ₂(D75K) and WT receptors. The α₁(K104D)β₂γ₂(D75K) GABA_AR was unable to fully rescue responses to WT levels of potentiation by 1 μm diazepam and Ro 15-4513 but was able to rescue the responses to 1 μm flunitrazepam and zolpidem. Each symbol represents the percent potentiation of the GABA EC_5–10 seen in one oocyte, and each bar represents the mean potentiation observed. Error bars represent the S.E.