FIGURE 1.

Velocity and percent of time spent running increase during the habituation period. (a, left) Schematic of 3D-printed headframe affixed to the surface of the skull with wings for head-fixing during running. (a, middle) Experimental timeline where headframe surgery takes place on day 0, and habituation consists of seven consecutive days beginning 24 hr after surgery (D1-D7). (a, right) Running wheel schematic where the head-fixed mouse can run forward (clockwise) or reverse (counterclockwise) on a cylindrical, voluntary running wheel. (b) Example running behavior trace for one animal shows running in both the forward and backward direction. Inset: blue-shaded areas show epochs of running, and non-shaded shows epochs where the animal is stationary on the wheel. (c) Velocity analysis for all animals (N = 18). The median velocity for each animal is plotted for each of the 7 days following headframe. Significant increase in velocity between day 1 and day 7 (day 1 median velocity = 0.92 ± 3.83 cm/s, day 7 median velocity = 3.92 ± 3.38 cm/s, p = .0004, Wilcoxon rank-sum test). Error bars are standard deviation. (d) Percentage of time spent running for all animals (N = 18). The median percentage of time spent running for each animal is plotted for each of the 7 days. Significant increase in the percentage of time spent running between day 1 and day7 (day 1 median time spent running = 6.92 ± 12.15%, day 7 median time spent running = 32.48 ± 15.95%, p = .000072, Wilcoxon rank-sum test). Error bars are standard deviation