The effect of displacement current on the measurement of reversal potential in squid giant axon.
The measurement of the sodium reversal potential (Erev), as that potential where the early current reverses during voltage clamp, was found to exceed the true Erev by 4.1 +/- 2.4 mV (mean +/- SD) in squid giant axon. This error was found in both intact and internally perfused axons and is due to interference from the displacement current. This was shown by subtraction of the current records obtained before and after treatment with tetrodotoxin (TTX). The error in Erev is proportional to (Td/gNA)12 where Td is the time constant of the displacement current.
D000818:Animals; D001369:Axons / Q000502:physiology*; D049832:Decapodiformes; D007473:Ion Channels / Q000502:physiology*; D012964:Sodium / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology
D007473:Ion Channels; D013779:Tetrodotoxin; D012964:Sodium