Cerebrospinal fluid helps remove toxins from our brain, especially while we are asleep, and that is one of the reasons why it is so necessary to sleep well and for enough time. In addition, decreased cerebrospinal fluid flow has been linked to brain deterioration, as occurs in neurodegenerative diseases such as Alzheimer’s.
Based on the evidence found in sleep studies, a team of scientists from Boston University (USA) has hypothesized that brain activity during wakefulness could also affect the flow of cerebrospinal fluid and have shown that manipulating blood flow in the brain with visual stimulation induces complementary fluid flow, a finding that could be useful in the treatment of Alzheimer’s and other conditions that have been associated with reduced cerebrospinal fluid flow.
The researchers tested their hypothesis by simultaneously recording human brain activity using functional magnetic resonance imaging (fMRI) and the velocity of cerebrospinal fluid flow while a group of people viewed a checkered pattern that flashed on and off. First, they confirmed that the checkered pattern induced brain activity and found that blood oxygenation recorded by fMRI increased when the pattern was visible and decreased when it was turned off. They then observed that cerebrospinal fluid flow negatively reflected the blood signal, increasing when the checkered pattern was off.
“We can induce large changes in cerebrospinal fluid flow in the awake human brain by displaying images with specific patterns”
Other tests showed that changing the length of time the pattern was visible affected blood and fluids in a predictable way, and that the link between blood and spinal fluid could not be explained by participants’ breathing or heart rate alone. . Although the researchers did not measure waste removal from the brain, the results show that simple exposure to an intermittent pattern can increase cerebrospinal fluid flow, which could be a way to counteract natural or unnatural reductions in fluid flow. that occur with aging or disease.
“This study found that we can induce large changes in cerebrospinal fluid flow in the awake human brain by displaying images with specific patterns. This result identifies a non-invasive way to modulate fluid flow in humans,” said Laura Lewis, lead author of the study, whose findings have been published in PLOS Biology.
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