Figure 2—figure supplement 2. | Optical electrophysiology for probing function and pharmacology of voltage-gated ion channels

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Optical electrophysiology for probing function and pharmacology of voltage-gated ion channels

Figure 2—figure supplement 2.

Affiliation details

Harvard University, United States; Howard Hughes Medical Institute, Harvard University, United States
Figure 2—figure supplement 2.
Download figureOpen in new tabFigure 2—figure supplement 2. Relationship between Nav1.7 current density and spike height.

(A) Combined current clamp and voltage clamp protocol in the presence of 3 μM amitriptyline to prepare cells with varying NaV1.7 capacities. Initially, a current clamp protocol was applied in which a depolarizing pulse led to amitriptyline binding and complete channel block. After a variable recovery period, Δt, a test pulse of current induced a voltage spike whose amplitude was recorded. The voltage during the prepulse and recovery periods was then replayed in voltage clamp mode to induce an identical level of channel block. A step depolarization to -20 mV induced a spike in NaV1.7 current whose amplitude was recorded. For details see Materials and methods. (B) Upper trace: current clamp recording showing voltage during 500 ms prepulse intervals, variable recovery period, and test pulses (asterisks). Bottom left: magnified view of voltage during test pulses. Bottom right: magnified view of NaV1.7 current during test pulse under voltage clamp. (C) Voltage spike amplitude as a function of NaV1.7 current amplitude for paired current-clamp and voltage-clamp recordings. Error bars represent s.e.m. of n = 8 cells.

DOI: http://dx.doi.org/10.7554/eLife.15202.006