The brain, as any neuroscientist will tell you, is still in many ways an undiscovered country. But now our maps of that country just got a lot better. Researchers at University of Rochester Medical Center have just published a paper detailing what they call the brain's built-in drainage system. It turns out that your brain is constantly being washed out by cerebrospinal fluid that passes between cells, clearing out proteins that can build up, kill neurons, and possibly lead to Alzheimers. Eventually these proteins are washed out of the brain entirely, flowing down the outside of the blood vessels in your gray matter, and back into your body. In a sense, this cerebrospinal fluid drainage is like garbage collection inside your brain.
When the researchers added fluorescent and radioactive tracers to the cerebrospinal fluid of live mice, the tracers quickly spread throughout the rodents' brains. Using two-photon microscopy to visualise the movement in real-time, the team saw cerebrospinal fluid permeating the entire brain through 'pipes' surrounding blood vessels, similar to the lymphatic system that services all other organs.
The pipes work on hydraulic principles, though, and so the system breaks upon opening, making it hard to identify it outside living organisms.
The researchers named this drainage system the "glymphatic system" because it resembles the lymphatic system and is also helped along by glial cells.
New Scientist continues:
The researchers found that the glymphatic system flushes waste from the brain through large drainage veins. That waste includes 55 per cent of the amyloid-beta removed from the rodent's brains.
"Removing waste is as vital to organ function as receiving nutrients," says Iliff. "So the failure of the glymphatic system is probably involved in many disease states – for example, Alzheimer's with its hallmark accumulation of amyloid-beta."
If it turns out that the glymphatic system is responsible for clearing away the brain debris that causes Alzheimers, there are a number of ways we could use the system to prevent or even roll back the effects of the disease. Now that we know this system exists, doctors can test Alzheimers patients to see whether their glymphatic system is compromised. It's possible that drug therapies could make the glymphatic system more efficient, pushing more fluid through brains suffering protein build up. One day, getting a brain cleanse may be as routine as getting your teeth cleaned.
Read more via New Scientist.