Shocking Effects of Sleep on Our Brain Uncovered

The human brain is a marvel of nature, capable of complex thought and memory. But what happens to our brains when we sleep? A 2019 study led by researchers from Boston University has provided some fascinating insights into this question. 
 
Published in Science News, the research focused on understanding how cerebrospinal fluid (CSF) interacts with neural activity during sleep. Neural activity is essential for processing and consolidating memories, while CSF clears metabolic waste products from the brain. The National Cancer Institute further explains that CSF flows around the brain and spinal cord, cushioning them against injury and providing nutrients. 
 
To understand whether these two processes are related, researchers used advanced neuroimaging technology to monitor physiological dynamics in the human brain during sleep. They recruited thirteen participants between ages 23 and 33 who were asked to lie inside an MRI machine as they fell asleep. 
 
The findings revealed that our brains are more active than previously believed while sleeping. During non-rapid eye movement or non-REM sleep, there's not just slow neural activity but also 'brain-wide pulsations in blood volume and CSF flow'. Every twenty seconds, fresh waves of CSF enter the brain, flushing out harmful proteins associated with diseases like Alzheimer's—a pattern co-author Laura Lewis described as "striking.". 
 
This discovery fills a critical gap in our understanding of how sleep contributes to overall mental health by clearing toxins from our brains. It was such a dramatic effect that we didn't know it happened at all," said Lewis. "Now we can glance at one region of someone's brain and immediately know their state." 
 
Social media users reacted with awe following news about this study’s results, which likened sleeping brains to going through cycles similar to laundry machines washing clothes clean. 
 
One Reddit user humorously equated these natural cleaning processes occurring during slumber with taking showers after another Reddit user shared news about this study on the r/todayilearned subreddit forum. 
  
User u/Combat_Armor_Dougram humorously concluded, "So brainwashing is real." 
 
However, it's worth noting that another study contradicts these findings. Published in Nature Neuroscience in May 2024, the research conducted on mice found a reduction of 'brain clearance' during sleep rather than an increase. 
 
This study concludes with a note of uncertainty: "How metabolites and toxins are cleared from the brain remains unresolved." This statement underscores how much more there is to learn about our brains and the vital role sleep plays in maintaining overall mental health. 
 
While it may feel disconcerting knowing your brain goes through its own washing machine cycle as you sleep, this process could be integral to maintaining cognitive function and staving off neurodegenerative diseases. So while we may not know everything about what happens to our brains when we're asleep just yet, one thing's certain: getting enough rest is vital for keeping our minds healthy.