Fig. 5. Measurement of the reversal potential during a membrane action potential.
All recordings were taken from a Loligo pealei axon at 15°C.
Holding potential, just before current clamping, was -65 mV. Axons were bathed
in 10K ASW (see Materials and methods). (A) A single membrane action
potential. (Bi) Seven similar action potential recording, which have been
voltage-clamped after 700 µs, superimposed. Voltage-clamp potentials are
from -70 mV to +50 mV in increments of 20 mV. (Bii) Paired current traces for
voltage traces in Bi demonstrating instantaneous jumps. (C) Results from nine
experiments similar to that in B but interrupted at different times. Reversal
potential (Erev), determined from instantaneous
current/voltage plots, plotted as a function of time and superimposed onto an
action potential.
