Newswise — Researchers at Boston University, USA report that the flow of cerebrospinal fluid in the brain is linked to waking brain activity. Led by Stephanie Williams, and publishing in the open access journal PLOS Biology on March 30th, the study demonstrates that manipulating blood flow in the brain with visual stimulation induces complementary fluid flow. The findings could impact treatment for conditions like Alzheimer’s disease, which have been associated with declines in cerebrospinal fluid flow.
Just as our kidneys help remove toxic waste from our bodies, cerebrospinal fluid helps remove toxins from the brain, particularly while we sleep. Reduced flow of cerebrospinal fluid is known to be related to declines in brain health, such as occur in Alzheimer’s disease. Based on evidence from sleep studies, the researchers hypothesized that brain activity while awake could also affect the flow of cerebrospinal fluid. They tested this hypothesis by simultaneously recording human brain activity via fMRI and the speed of cerebrospinal fluid flow while people were shown a checkered pattern that turned on and off.
Researchers first confirmed that the checkered pattern induced brain activity; blood oxygenation recorded by fMRI increased when the pattern was visible and decreased when it was turned off. Next, they found that the flow of cerebrospinal fluid negatively mirrored the blood signal, increasing when the checkered pattern was off. Further tests showed that changing how long the pattern was visible affected blood and fluid in a predictable way, and that the blood-cerebrospinal fluid link could not be accounted for by only breathing or heart rate rhythms.
Although the study did not measure waste clearance from the brain, it establishes that simple exposure to a flashing pattern can increase the flow of cerebrospinal fluid, which could be a way to combat natural or unnatural declines in fluid flow that occur with age or disease.
Laura Lewis, senior author of the study, adds, “This study discovered that we can induce large changes in cerebrospinal fluid flow in the awake human brain, by showing images with specific patterns. This result identifies a noninvasive way to modulate fluid flow in humans.”
Citation: Williams SD, Setzer B, Fultz NE, Valdiviezo Z, Tacugue N, Diamandis Z, et al. (2023) Neural activity induced by sensory stimulation can drive large-scale cerebrospinal fluid flow during wakefulness in humans. PLoS Biol 21(3): e3002035. https://doi.org/10.1371/journa
Author Countries: United States of America
Funding: see manuscript
Competing interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: L.D.L. is an inventor on a patent application for an MRI method for measuring CSF flow and is an Academic Editor at PLoS Biology. The other authors report no competing interests.
About PLOS Biology
PLOS Biology is an open-access, peer-reviewed journal published by PLOS, featuring research articles of exceptional significance, originality, and relevance in all areas of biology. For more information visit http://journals.plos.org/plosb
Media and Copyright Information
For information about PLOS Biology relevant to journalists, bloggers and press officers, including details of our press release process and embargo policy, visit http://journals.plos.org/plosb
PLOS Journals publish under a Creative Commons Attribution License, which permits free reuse of all materials published with the article, so long as the work is cited.
PLOS is a nonprofit, Open Access publisher empowering researchers to accelerate progress in science and medicine by leading a transformation in research communication. We’ve been breaking boundaries since our founding in 2001. PLOS journals propelled the movement for OA alternatives to subscription journals. We established the first multi-disciplinary publication inclusive of all excellent research regardless of novelty or impact, and demonstrated the importance of open data availability. As Open Science advances, we continue to experiment to provide more opportunities, choice, and context for readers and researchers. For more information, visit https://www.plos.org/who-we-ar
This press release refers to upcoming articles in PLOS Biology. The releases have been provided by the article authors and/or journal staff. Any opinions expressed in these are the personal views of the contributors, and do not necessarily represent the views or policies of PLOS. PLOS expressly disclaims any and all warranties and liability in connection with the information found in the release and article and your use of such information.