Fig. 1
From: Flow of cerebrospinal fluid is driven by arterial pulsations and is reduced in hypertension
CSF in the perivascular space is transported via bulk flow. CSF flow was imaged in live mice through a cranial window using two-photon microscopy. To visualize the CSF, fluorescent microspheres were infused into the cisterna magna. a Images for particle tracking velocimetry were acquired at 30 Hz. Blood vessels were labeled with an intravenous (i.v.) dextran, while microspheres appear green; (inset) the magenta arrows show the instantaneous velocity of each microsphere. b Superimposed trajectories of tracked microspheres show that particles are transported primarily within large PVSs. Scale bar: 40 µm. c The time-averaged velocity field (green arrows) shows that net transport is in the same direction as the blood flow. d The local time-averaged flow speed shows that the interior region of the arterial bifurcation is nearly stagnant. Scale bars: 40 µm. e Average flow speed profiles plotted as a function of distance from the arterial wall. Colored lines in d indicate the location of each profile. f Mean flow speeds, g Reynolds, and h Péclet numbers for the time-averaged flow, mean ± SEM, n = 13 mice
