Actin filament–disrupting drugs impact cilia membrane corral permeability. (A–C) MSD(τ) plots from 5 Hz GPCR-tracking experiments with and without F-actin–perturbing drugs. GPCRs were tracked for 5 min without drug, incubated with drug for 10 min, and tracked again for 5 min. Similar experiments were performed with DMSO alone. Quotients of MSD(τ = 4) before and after treatment (QMSD(4)) are shown in G. (D–F) 200-Hz tracking and fitting with corralled diffusion model with drug showed that F-actin perturbation altered the permeability of the corral boundaries but had no effect on the size of the corrals or D_m1. Note different scaling of ordinates. (H) Mean sizes of the corrals measured were not significantly different. (I) Inverse mean probability of boundary crossing, 1/P_bc. 1/P_bc is a measure of the number of times a GPCR encounters a boundary before it manages to cross. (J) The mean corral diffusion coefficients in each condition are not statistically different. (G–J) ND, no drug (vehicle control). Error bars are SEM. (G and I) Asterisks denote significant difference from DMSO at P < 0.05 (G) or P < 0.01 (I), as determined by ANOVA and Bonferroni post hoc analysis. In A–C and G, latrunculin A 0.1 µM, n = 7; five independent experiments; latrunculin A 0.5 µM, n = 11; six independent experiments; cytochalasin D 13 µM, n = 14, nine independent experiments; cytochalasin D 2 µM, n = 11; six independent experiments; DMSO controls, n = 6; two independent experiments. In D–F and H–J, ND, n = 18, seven independent experiments; jasplakinolide, n = 7; two independent experiments; latrunculin A n = 11, six independent experiments; cytochalasin D, n = 7, two independent experiments.