Figure 2. Inclusions and small particles of aggregated mHtt are mobile.

(A) Representative time-lapse sequence of an IB moving within the cytoplasm. Numbers indicate elapsed time in seconds. Bar, 1 μm. (B) Representative time-lapse frames showing a small particle (arrows). Upper panels, denoised images; lower panels, the same images processed with the SpotTracker Spot Enhancing Filter 2D. Numbers indicate elapsed time in seconds. Bar, 1 μm. (C) Track of the particle indicated in (B). (D, E) The log of mean squared displacement (d²) is plotted against the log of time (t) for 23 small particles (D) or 23 IBs (E). Each fitted line is derived from a single small particle. The slope of the line gives the value for the exponent α in the diffusion equation. The red dashed reference line shows α = 1 (random diffusion). A slope >1 indicates directed movement. (F) The average value of α was determined for small particles and IBs. **P = 0.0006, unpaired two-tailed t test with unequal variance, n = 23 for each group; whiskers indicate minimum and maximum values.