Table 2. The effect of patch excision on the channel open duration and voltage sensitivity.

		Cell attached			Inside out
Receptor	Agonist	τo (ms)	f	n	τo (ms)	f	n	Ratio τo i/o:c/a
αβγδ	ACh	4.4	0.20	1	2.11	0.28	1	0.48
αβγδ	CCh	1.32 ± 0.37	0.27 ± 0.04	5	0.67 ± 0.17	0.37 ± 0.08	4	0.51*
αY93Fβγδ	ACh	1.04 ± 0.06	0.27 ± 0.16	2	0.52 ± 0.09	0.36 ± 0.08	3	0.50*
αβδε	ACh	0.39 ± 0.09	0.39 ± 0.04	2	0.52 ± 0.12	0.23 ± 0.11	3	1.33
αβδε	CCh	0.21 ± 0.02	0.35 ± 0.08	2	0.21 ± 0.06	0.32 ± 0.01	2	1.0
αβδε	TMA	0.25	0.22	1	0.26	0.22	1	1.04
αY93Fβδε	ACh	0.20 ± 0.03	0.23 ± 0.01	3	0.16 ± 0.01	0.24 ± 0.006	3	0.80
αY93Fβδχ9	ACh	0.52 ± 0.04	0.30 ± 0.03	2	0.73 ± 0.08	0.19 ± 0.04	2	1.40*
αβδχ19	TMA	0.32 ± 0.04	0.32 ± 0.006	3	0.26 ± 0.0	0.31 ± 0.007	2	0.81
αβδχ32	TMA	0.27 ± 0.11	0.28 ± 0.07	3	0.29 ± 0.05	0.22 ± 0.006	3	1.07
αβδχGINE	TMA	0.57 ± 0.01	0.29 ± 0.05	3	0.29 ± 0.03	0.28 ± 0.05	3	0.51*
αβδγWA	TMA	1.36 ± 0.07	0.24 ± 0.03	3	1.43 ± 0.05	0.24 ± 0.04	3	1.05

The channel open duration at 0 mV membrane potential (τ_o) and voltage sensitivity (f) were calculated using eqn (1) (see Methods). Values are shown as means ±s.d.from n experiments. The structures of the constructs used are given in Methods and Fig. 5. The degree of voltage sensitivity (f) can be converted to mV per e-fold change by dividing 25 mV by f. Asterisks in column ‘ratio τ_o’ denote statistically significant (P < 0.05) changes.