Supplementary Figure 3: Pupils dilate when mice move.
From: Active control of arousal by a locus coeruleus GABAergic circuit
a, Simultaneous recordings of pupil size and movement of ears, paws, neck, and nose for an example mouse. The average of all four movement traces is shown in the average movement trace. Quiet (red) and active (white) periods of movement were isolated using a threshold of the average movement trace. b, Methods to evaluate mouse movements. Regions of interest were drawn around each body part and the movement was extracted by pixel analysis. We calculated the average difference in pixel value for each frame, normalized by the reference region of interest. c, Example cumulative histogram comparing pupil size distribution of active and quiet epochs of movement. d,e, Average and standard deviation of pupil size are larger during active epochs (***P = 0.00099 and **P = 0.0085 using a two-tailed paired t-test with t4 = −9.89 and t4 = −4.83 values, respectively). f, Normalized cross-correlation of pupil versus movement. We observed an increase in movement preceding pupil dilation. N = 5 mice for d–f.
