video: This movie demonstrates the type of imaging used in the present article, called 2-photon microscopy. The authors used a specially-designed microscope to image the surface of the brain in a live mouse in which the brain vasculature was visualized by injecting a fluorescent tracer intravenously. In order to evaluate the routes of CSF movement into and through the brain, they injected a second fluorescent tracer into the CSF that surrounds the brain, then imaged its movement through the first 240μm of the cerebral cortex. CSF was observed to first travel along the arteries on the brain surface. Where these arteries turn and dive into the brain tissue, CSF likewise entered along the outside of the arteries. From these "paravascular" spaces, CSF moved into and through the brain tissue itself. This video relates to a paper that appeared in the Aug. 15, 2012 issue of Science Translational Medicine, published by AAAS. The paper, by Dr. J.J. Iliff at the University of Rochester Medical Center in Rochester, N.Y., and colleagues, was titled, "A Paravascular Pathway Facilitates CSF Flow Through the Brain Parenchyma and the Clearance of Interstitial Solutes, Including Amyloid Beta." view more
Credit: Movie from J. Iliff and M. Nedergaard