Table 1. The summary of the effects of 1 μM 3α5αP on the intracluster open times from the α1β2γ2L wild-type receptor, and α1Q241W, α1Q241L, and α1Q241S mutant receptors.

The intracluster open time histograms were fitted to sums of three exponentials (wild-type and α1Q241W) or two exponentials (α1Q241L and α1Q241S). In the wild-type receptor, 3α5αP potentiates the currents by enhancing the mean duration and prevalence of OT3. Additionally, the presence of steroid influences the mean duration and prevalence of OT1, and the prevalence of OT2. The presence of steroid was without effect on the properties (mean durations and fractions) of channel openings from the α1Q241W and α1Q241L receptors, but prolonged the mean duration of OT2 in the α1Q241S receptor. Wild-type data are from Li et al. (2007b). The statistical analysis applies to the effect of the steroid for a given receptor (wild-type or mutant).

Mutation	GABA (μM)	3α5αP (μM)	OT1 (ms)	Fraction OT1	OT2 (ms)	Fraction OT2	OT3 (ms)	Fraction OT3	n
None	50	-	0.28±0.05	0.22±0.02	3.0±0.7	0.65±0.06	7.3±3.2	0.13±0.07	4
None	50	1	0.41±0.04*	0.39±0.07**	2.4±0.9	0.23±0.03***	14.1±2.1*	0.38±0.04*	3
α1Q241W	10	-	0.33±0.08	0.26±0.09	2.2±1.5	0.22±0.07	9.6±4.1	0.52±0.12	4
α1Q241W	10	1	0.30±0.04	0.33±0.06	3.1±2.3	0.27±0.19	8.5±3.2	0.40±0.17	3
α1Q241L	50	-	0.60±0.25	0.47±0.32	1.9±0.7	0.53±0.32	-	-	4
α1Q241L	50	1	0.54±0.14	0.23±0.03	2.2±0.1	0.77±0.03	-	-	3
α1Q241S	50	-	0.69±0.21	0.60±0.21	1.8±0.6	0.40±0.21	-	-	7
α1Q241S	50	1	0.66±0.16	0.40±0.13	5.7±1.5***	0.60±0.13	-	-	6

^*P < 0.05

^**P < 0.01

^***P < 0.001.