Figure 8
HyNaCs are activated by Hydra-RFamide II. A) Representative current traces showing concentration-dependent activation of HyNaC2/4/6 and HyNaC2/11/5 by Hydra-RFamide II; oocytes had been injected with EGTA. Dashed lines represent the zero current level. B) Concentration-response curves for HyNaCs and Hydra-RFamide II. Currents were normalized to the currents at highest agonist concentration, which had amplitudes of 5.3 ± 1.0 μA (n = 14; 2/3/5), 2.2 ± 0.4 μA (n = 7; 2/11/5), 9.2 ± 1.7 μA (n = 8; 2/3/6), 4.7 ± 0.8 μA (n = 12; 2/4/6), 11.8 ± 4.0 μA (n = 8; 2/3/7), 3.6 ± 1.3 μA (n = 8; 2/9/7) and 1.1 ± 0.4 μA (n = 7; 2/10/7), respectively. Lines represent fits to the Hill equation. EGTA, ethylene glycol tetraacetic acid; HyNaC, Hydra Na+ channel.