Table 1.

Potential dependence of erg availability

Experiment	f	s	kf(mV)	ks(mV)	V1/2,f(mV)	V1/2,s(mV)
1	0.24	0.76	7.7	12.4	−70.3	−114.1
2	0.36	0.64	4.1	12.7	−71.5	−109.8
3	0.40	0.60	8.7	9.7	−78.3	−117.8
4	0.50	0.50	9.8	7.8	−60.2	−114.6
5	0.54	0.46	8.6	12.7	−74.9	−113.7
6	0.62	0.38	9.8	6.1	−85.4	−123.2
7	0.65	0.35	7.0	10.1	−78.2	−111.8
8	0.71	0.29	6.0	5.5	−74.8	−121.7
9	0.73	0.27	8.5	10.6	−71.4	−125.5
10	0.81	0.19	8.4	5.6	−74.7	−121.2
11	0.83	0.17	6.6	8.2	−70.6	−116.3
Mean ±s.e.m.			7.7 ± 0.5	9.2 ± 0.8	−73.7 ± 1.9	−117.2 ± 1.5

The potential dependence of erg-like channel availability was tested with a constant pulse to −120 mV preceded by 2 s prepulses to membrane potentials between 0 and −140 mV. The peak current amplitudes recorded with the test pulse were normalized, plotted against prepulse potential and fitted with the sum of two Boltzmann functions: f/(1 + exp(−(V−V_1/2,f)/k_f)) +s/(1 + exp(−(V−V_1/2,s)/k_s)). Abbreviations: f and s, relative amplitude of the fast and slow current component, respectively; k_f and k_s, slope factor of the Boltzmann function related to the fast and slow current component; V_1/2,f and V_1/2,s, prepulse potential at which 50% of the fast or slow current component is deactivated. Same experiments as those of Fig. 4.