Figure 2. Fragile X larvae crawl more slowly and turn more often. (A) The Mean Squared Displacement (MSD) for crawling larvae from the Fragile X model (dfmr1⁴) is lower than that for wild type larvae w[1118] indicating crawling defects. The smaller y-intercept, inset in (A), is indicative of a smaller mean velocity. Larvae from the Drifter strain (Df), which have decreased levels of the ion channel pickpocket1 that is over abundant in Fragile X individuals, show an opposite trend demonstrating the dynamic range of the method. (B) The Direction Autocorrelation (DAC) shows that the dfmr1⁴ larvae turn more often than wild type larvae at small times and that the Df larvae turn significantly less. Error is standard error of the mean and is shown as a shadowed region around the trace for clarity. MSD error is smaller than the data point symbols and not shown on the logarithmic plot for clarity. Symbols and colors: cyan circles are Drifters, black squares are wild type and magenta triangles are Fragile X larvae, arranged in this order from top to bottom in the MSD plot in (A). (Number of larvae tracked: WT (25), dfmr1⁴ (24), Drifter (17))