Fig. 5: 40 Hz light flickering enhances the glymphatic influx through increased arterial vasomotion.

a High-frequency orthogonal line scans were generated across surface and penetrating arteries (scale bar, 50 μm). b Representative raw X–t scans were processed with thresholding to enhance edge detection, allowing for the measurement of luminal diameter over time. c Representative images of vasomotion after 40 Hz light flickering or exposure to normal light in awake mice. d Vasomotion was measured from ascending arteries: after exposure to 40 Hz light flickering for 30 min, arterial vasomotion was significantly higher than after exposure to normal light in these awake mice. e, f Representative images (scale bar, 1 mm) of laser speckle flowmetry showing that 40 Hz light flickering increased cortical cerebral blood flow in WT mice, as quantified in f (n = 6 mice/group, mean ± SEM in the bar graphs, *P < 0.05, paired Student’s t-test). g–j 40 Hz light flickering did not significantly modify either heart rate, systolic blood pressure, mean blood pressure or diastolic blood pressure, measured using a non-invasive tail-cuff method (n = 7 mice/group, mean ± SEM in the bar graphs, ns, not significant, paired Student’s t-test).