Table 2. Regression results from fitted zolpidem responses at wild-type and concatenated GABA_ARs.

		Zolpidem
Construct	Subunit	EC50 (µM)	pEC50	n	GABA316 µM (nA)
α1 + β2 1:50		No effect		7	2,100 ± 300
α1 + β2 50:1		No effect		6	750 ± 250
α1 + β2 + γ2 5:1:5		0.11	6.95 ± 0.02	11	2,900 ± 500
Dimeric constructs
β2-23-α1	γ2	0.10	7.00 ± 0.03	8	7,600 ± 700
α1-10-β2	γ2	0.18	6.74 ± 0.03	7	14,000 ± 6,000
α1-9a-β2	γ2	0.19	6.72 ± 0.03	14	7,000 ± 1,000
α1-6a-β2	γ2	0.15	6.83 ± 0.03	8	4,000 ± 500
α1-3a-β2	γ2	0.20	6.71 ± 0.04	7	5,600 ± 1,300
α1-0a-β2	γ2	0.21	6.68 ± 0.03	12	280 ± 50
Tetrameric constructs
α1-10-β2-α1-β2	γ2	0.10	7.00 ± 0.03	9	5,000 ± 500
α1-10-β2-α1-γ2	β2	0.092	7.04 ± 0.02	7	5,800 ± 400
Pentameric constructs
α1-(-1a)-β2-α1-β2-γ2		0.17	6.76 ± 0.02	6	150 ± 50a
α1-(-1a)-β2-α1-γ2-β2		0.19	6.72 ± 0.02	12	2,300 ± 300a
γ2-15a-β2-α1-β2-α1		0.15	6.82 ± 0.02	9	6,100 ± 1,200
γ2-13a-β2-α1-β2-α1		0.22	6.65 ± 0.02	11	4,400 ± 600a
γ2-11a-β2-α1-β2-α1		0.27	6.57 ± 0.03	12	2,000 ± 30a
γ2-10a-β2-α1-β2-α1		0.14	6.86 ± 0.02	11	1,700 ± 200a
γ2-9a-β2-α1-β2-α1		0.17	6.78 ± 0.03	14	800 ± 150a
Mutant constructs
α1-9a-β2	γ2(A118R)	3.4	5.46 ± 0.04	11	8,600 ± 1,100
α1-0a-β2	γ2(A118R)	2.0	5.70 ± 0.03	7	990 ± 90
α1R94A + β2 + γ2 5:1:5		0.20	6.71 ± 0.02	7	990 ± 110a
γ2-11a-β2-α1-β2-α1R94A		0.36	6.44 ± 0.03	11	350 ± 50a
γ2-11a-β2-α1-β2-α1R94A	α1	0.20	6.71 ± 0.03	9	510 ± 130a

Data points were fitted to the Hill equation with bottom set to 0 and Hill slope set to 1 by nonlinear regression. Fitted potencies of zolpidem are presented as EC₅₀ in µM and pEC₅₀ ± SEM where p = −Log for the indicated number (n) of individual oocytes. The average peak-current amplitudes obtained with GABA_{316 µM} applications are presented as mean ± SEM in nA for the tested oocytes. No effect, no positive enhancement of GABA_control-evoked currents was observed.

^aDue to the GABA EC₅₀ value on this receptor, GABA_{316 µM} applications do not represent a maximal EC₁₀₀ concentration.