Extended Data Fig. 2: Motion tracking is robust with minimal z-axis displacement of the brain and skull during locomotion.
From: Brain motion is driven by mechanical coupling with the abdomen
a. Typical tracking locations were selected for fluorescent microspheres (magenta) and GFP-expressing brain tissue (green) as well as a baseline location with no visible fluorescence (brown). b. The mean fluorescence in both locations was ~9% lower during locomotion than the mean fluorescence when the animal was still in n = 1 mouse. c. Using the axial point spread function of the two-photon microscope, a displacement in z of ~1 µm will drive a fluorescence decrease of ~9%. It is likely that the brain and skull are shifting in the same direction in z as the calculated values are so similar, possibly due to slight movements of the whole head and/or head fixation apparatus. d. Static microspheres on a slide were imaged to demonstrate error in the tracking software. e. The tracking software detected no motion from the static fluorescent microspheres. f. Static FITC-stained filter paper on a slide was imaged to demonstrate to simulate brain tissue. g. The tracking software detected no motion from the static FITC paper.
