Researchers at Boston University have discovered that the flow of cerebrospinal fluid (CSF) in the brain is linked to waking brain activity. The study, led by Stephanie Williams and published in the open access journal PLOS Biology, demonstrated that manipulating blood flow in the brain with visual stimulation caused complementary fluid flow. The researchers found that reduced flow of CSF can lead to a decline in brain health, such as in Alzheimer’s disease. They then hypothesised that brain activity while awake could also affect the flow of CSF. The results of their study showed that simple exposure to a flashing pattern can increase the flow of CSF, which could be a way to combat the natural or unnatural declines in fluid flow that occur with age or disease.
Cerebrospinal fluid, much like the kidneys, helps remove toxins from the brain, particularly when we sleep. Reduced flow of the fluid is known to be associated with declines in brain health, including declines found with Alzheimer’s disease. Based on sleep studies, the researchers hypothesised that brain activity while awake could affect the flow of CSF, hence the study to test this theory.
Brain activity was recorded through functional magnetic resonance imaging (fMRI) and the speed of CSF flow was recorded. Participants were shown a checkered pattern that turned on and off, and the researchers found 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. The flow of CSF 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.
The study discovered that it is possible to induce large changes in CSF flow that relate to blood flow in the awake human brain. This resulted in the identification of a non-invasive way to modulate fluid flow in humans.
The results of the study could impact the treatment of conditions like Alzheimer’s disease, as it displays a potential method to manipulate the fluid flow in the brain. However, it is important to note that the study did not measure waste clearance from the brain, therefore the impact of the study in relation to waste clearance needs further examination.
In conclusion, the flow of cerebrospinal fluid (CSF) in the brain is linked to the activity of the brain while awake. Simple exposure to a flashing pattern can increase the flow of CSF. This could be a way to combat the natural or unnatural declines in fluid flow that occur with age or disease. Further research is needed to extend the results of the study to waste clearance from the brain.