... (TTX), indicating that the Na + channel belongs to a group of TTX-resistant Na + channels. The Ca 2+ current was blocked by nifedipine (10 μmol l –1 ) and Co 2+ (5 mmol l –1 ),indicating that the Ca 2+ channel is L-type. The K + current possessed a unique property of long-lasting inactivation. The K...

... (0.5 mmol l –1 ), but not affected by internal GDPβS (1 mmol l -1 ). The voltage of half-maximum ( V 1/2 )activation was –46 mV in both perforated and conventional modes. V 1/2 of inactivation was –80 mV in perforated mode and –86 mV in conventional mode. Internal GTPγS (0.5 mmol l –1 ) shifted the V 1...

... in the half-inactivation and a negative shift in the half-activation potentials for the sodium current, accompanied by a slowing of the rate of inactivation to half of the experimentally observed values. This suggests that once-only spiking can be attributed to the steady-state values of activation...

... charges in this segment. Despite their charge differences, both these jellyfish channels produce currents with activation and inactivation curves shifted by approximately +40 mV relative to other Shaker currents. Adding charge without changing segment length by mutating the N-terminal side of jShak1 S4...

... resting potential (about −70 mV) did not produce a regenerative potential. Sodium and calcium currents were observed under voltage-clamp. It was shown that the sodium spike cannot develop at the usual resting potential since sodium channels are already partially inactivated; the spike can appear after...