Immobilization of intramembrane charge in Myxicola giant axons.
1. Immobilization of gating charge was examined in Myxicola giant axons dialysed with Cs+. 2. With increasing pulse durations the ratio QOFF/QON decreases to as little as 0.25 with a time constant of 3.2 msec determined from composite data. Na inactivation time constants measured in the same axons ranged from 0.8 to 1.5 msec. A slow component of QOFF tends to appear as QOFF/QON decreases. 3. Both QON and QOFF may be decreased by a prepulse with no change in their time course. In this case the time course of the decrease is similar to that observed for INA. 4. The normalized steady-state charge immobilization curve is shifted in the depolarized direction by 15--20 mV from the normalized Na inactivation curve.
D000818:Animals; D001369:Axons / Q000502:physiology*; D066298:In Vitro Techniques; D007700:Kinetics; D008564:Membrane Potentials; D011077:Polychaeta / Q000166:cytology / Q000502:physiology*; D012964:Sodium / Q000502:physiology
D012964:Sodium