Figure 4. | 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 4.

Affiliation details

Harvard University, United States; Howard Hughes Medical Institute, Harvard University, United States
Figure 4.
Download figureOpen in new tabFigure 4. Effect of PF-04856264, a subtype-specific blocker, on NaV1.7-OS HEK cells.

(A) Dose-response curves for PF-04856264 when stimulated with prepulses of different durations and with different bath K+ concentrations (n = 4 wells for each concentration). The optical protocol was as in Figure 3B, with prepulse duration specified in figure legends. (B) Comparison between membrane voltage predicted by the Nernst Equation (assuming pure K+ conductance) and recorded by manual patch clamp, as a function of bath [K+] (n = 4–7 cell clusters per data point). (C) Use-dependent inhibition of spiking in NaV1.7-OS HEK cells by PF-04856264, at 8 mM external K+. Cells were stimulated with eight pulses of blue light (20 ms, 50 mW/cm2) at 5 Hz and 10 Hz and QuasAr2 fluorescence was monitored with 635 nm excitation, 400 W/cm2. After photobleaching correction, the QuasAr2 fluorescence in the absence or in the presence of 100 nM PF-04856264, was normalized to peak amplitude of the first spike at 5 Hz in the absence of the drug. Each trace was averaged from 4 wells. Inset: structure of PF-04856264.

DOI: http://dx.doi.org/10.7554/eLife.15202.011