Fig. 3: Assessing altered cell physiology in mutants affecting synaptic transmission and ion channels, using the OVC.
From: All-optical closed-loop voltage clamp for precise control of muscles and neurons in live animals
A unc-13(n2813) mutant and wild type animals were subjected to OVC depolarization, to +5% ΔF/F0. Mean wavelength traces (± S.E.M.), wild type: n = 9, unc-13(n2813): n = 10. B Mean wavelength required during the depolarization step to hold +5% ΔF/F0 (p = 0.0012, n—numbers as in A). C Membrane resistance was analyzed in wild type and unc-13 mutant muscles. wild type: n = 10, unc-13(n2813): n = 9. D, E Current ramps (0-20 pA over 100 ms; cyan) were injected into wild type and unc-13 mutant muscles and the induced voltage increases were aligned to the peak (p = 0.74). wild type: n = 11, unc-13(n2813): n = 5. F Group data of induced voltage increases in D, E (p = 0.04, n—numbers as in D, E). G–I Optical recordings of spontaneous APs in wild type animals, unc-13(n2813) and egl-19(n2368) mutants. Overlay of single (each two are highlighted in cyan) and mean (± S.E.M.) traces. wild type: n = 6, 27 APs analyzed; unc-13(n2813): n = 5, 26 APs analyzed, egl-19(n2368): n = 7, 28 APs analyzed. J, K Statistical analysis of peak AP amplitude (wt/unc-13: p = 8.27E-4, wt/egl-19 p = 3.04E-4) and AP duration (at FWHM; wt/unc-13: p = 0.0082, wt/egl-19 p = 1.53E-6) of data in G–I. n—numbers as in G–I. L All-optical I/V-relationship (mean ± S.E.M.) obtained in wild type (n = 17) and egl-19(n2368) mutants (n = 14) (2% p = 0.018, 3% p = 9.36E-9, 4% p = 7.26E-10, 5% p = 7.92E-9). M Data in L were transformed to I/V-relations (mean ± S.E.M.), using calibrations in Fig. 2J, L. The currents were normalized using capacitance measured in patch-clamped muscle cells (analogous to Fig. 1I). Data obtained for wild type (gray, n = 17) was deduced from egl-19 data (yellow, n = 14), generating a difference curve (dashed, yellow), and compared to difference data obtained by electrophysiology44 (n = 16) in wild type and egl-19(n2368) mutants (blue). Two-sided t test with Bonferroni correction in (B, C, F, J, K). ***p ≤ 0.001, **p ≤ 0.01, *p ≤ 0.05 and box plots (median, 25th–75th quartiles); open dot: mean; whiskers: 1.5× IQR. n—numbers refer to independent biological replicates (animals) (A–M). Source data are provided as a Source data file.
