Figure 5.

VIP alters CFTR dynamics, and its effects are blocked by Ami. (A) Mean squared displacement D_macroτ increases linearly as a function of τ under all conditions, and its slope (D_macro) yields the effective macroscopic diffusion coefficient for the unconfined CFTR population. (B) Mean squared displacement D_microτ increases linearly for the first few temporal lags under all conditions, and then its slope decreases at long τ. The first three D_microτ values were fitted with straight lines as shown to obtain the initial slope and D_micro, which quantifies CFTR mobility inside confinements (microdomains). VIP treatment resulted in a smaller D_micro compared with Ctr conditions, and this decrease was abolished by pretreating cells with Ami to inhibit ceramide production. (C) Amplitudes of the macro (${\varphi }_{macro}$, line only) and micro (${\varphi }_{micro}$, diamond symbols) components of the k-space correlation function and their dependence on τ. Mean ± SEM. For the number of cells analyzed, see Table 1.