3. Rebuilding Tissues
4. A brand new use—Cleaning the Brain (transporting and washing out toxins)
What Happens When You Don’t Sleep Well?
Much higher rates of:
1. Heart disease
2. Heart Attack
6. Crankiness, Tiredness, Poor Healing, Poor Performance—and shorter lives.
How Does the Brain “Cleanse”?
Researchers under Maiken Nedergaard at the University of Rochester last year discovered the “glymphatic system” in the brain of the mouse. It does much of what lymph does in other tissues —transport loads of stuff that blood does not carry. Some are nutrients, some are difficult to obtain proteins. Other substances pumped through the system are waste products—including clumps of amyloid and other proteins that many think help produce major neurodegenerative diseases—like Alzheimer’s, other dementias, and Parkinsonism.
Last week the same team announced the glymphatic system—at least in mice—is ten times more active in sleep than during wake. For humans this would mean something like your high school football field suddenly turns into an NFL football stadium—but only at night.
In sleep something wild happens. Glia cells—brain cells which vastly outpopulate nerve cells—stick tubes all around arteries and veins. Then they transport many materials. It’s a bit like the emergency piping we use to get around an obstruction, but on a major scale. Simultaneously, as they put together all these tubes and corridors, the glia appear to shrink. Now the complex mass of living stuff in the brain has a lot more open space to let molecules and water through. The flow through rate is much faster.
In the case of amyloid, which creates many of the deadly plaques of Alzheimer’s, over half its removal occurs through the glymphatic system. It looks like if you want to get rid of amyloid you need to sleep—and probably sleep well.
Why Wasn’t This System Discovered Sooner?
1. Academic silos. Most neuroscientists study neurons. They’re sexy. The many billions of other cells in the brain, mainly glia, are considered “support cells” or stuff used for “housekeeping.” Not sexy. Even though glia are critical to fighting off infection, keeping neurons alive, and setting up their own networks of information, they receive scant respect.
Academic silos are powerful. Cells are “supposed” to do certain things—and that’s that. It took over a century for people to realize humans grow new brain cells throughout their adult lives— one of Broca’s 19th century “dogmas.” Similarly, fat cells store fat, right? Except fat cells are also the biggest endocrine—hormonal—gland in the body.
Biological tissues are not aware of the academic functions we’ve given them. Bodies are systems of information—not a group of precisely defined textbook headings. Nitric oxide was a “harmless”, useless “waste product” until it turned out to be one of the most powerful arterial vasodilators—and a critical communication molecule for dozens of processes. Much of the action in headaches, backaches and overall human pain involves “simple” connective tissue. But most clinicians and technicians prefer instead to think and talk about muscle, joints, tendons and ligaments.
2. Funding. Even Nedergaard’s team is quick to point out how their work this “opens up” a new way of understanding and attacking dementia. There’s lot of research funding for dementia. Funds to figure out how “waste disposal” performs in the brain—well, we can knock that off in the next Congressional sequester.
Pity the poor glia. And pity us.
Is Cleansing the Brain Important to Its Function?
Sure. Without all that cleaning we’d probably die. Glymphatic action will no doubt eventually affect lots of common diseases—including the ones that make us stop moving and stop thinking.
Consider a city filled with non-functioning water and sewer pipes. People get sick, epidemics start and then explode. Next, let those pipes really fall apart. You’ve gone from a city to a nascent archeologic ruin.
Is “Brain Cleaning” the Main Function of Sleep?
Sleep has dozens of “functions.” Finding out the glymphatic system is superactive during sleep just adds one more.
And helps demonstrate the belief that “activity” and “rest” are fully separate is pure hokum.
Life is fast. Absurdly fast. Proteins do much of the work of life. Trillions and trillions of them interact every second in just about every cell you’ve got.
They work so hard that they quickly fall apart. Then they’re repaired. Then they fall apart again.
Soon “waste removal” and “garbage disposal” take over. The same stuff gets recycled into other proteins.
This continuous renewal and rebuilding goes on all the time. Some of its more specialized actions go on in sleep.
But the need for regeneration is constant. Without it, we cease to exist.
Rest is just as active as “activity.” This is really a matter of semantics. The stuff we see “move” is “active.” The stuff we don’t see move is “passive.” So we call that “rest.”
Like most things in life, what you don’t see is more important than what you do see.
Life moves fast. Rest rebuilds and regenerates. And sleep is just a part of rest.