Glowing Mouse Heads and How Our Brains Get Washed

Herewith, edited excerpts from a Washington Post article of special interest to people with brains:

The lymph network carries immune cells throughout the body and removes waste and toxins. It was accepted wisdom for more than 300 years that the network didn’t extend into the brain. 

Three years ago, scientists trying to develop a more precise map of the lymphatic system used genetically-modified mice whose lymphatic vessels glowed when illuminated by a particular wavelength of light. The mice had been given a gene from a species of glowing jellyfish.

Seeing that the mouse’s heads glowed, the researchers realized that the lymphatic vessels extended into the brain after all. This was surprising, to say the least: In the 21st century, major findings involving basic human anatomy are rare. “These days, you don’t make discoveries like this”, one of the scientists said.

Since the lymph network also extends into human brains, this discovery has major implications for a wide variety of brain diseases, including Alzheimer’s, multiple sclerosis, stroke and traumatic brain injury.

Researchers have identified two networks: the vessels that lead into and surround the brain, and those within the brain itself. The latter is called the “glymphatic” system for the glia, the kind of neuron that makes up the lymphatic vessels in the brain. The glymphatic vessels carry cerebrospinal fluid and immune cells into the brain and remove cellular trash from it.

There is evidence that when the systems malfunction, the brain can become clogged with toxins and suffused with inflammatory immune cells. Over decades, this process may play a key role in Alzheimer’s disease, Huntington’s disease, Parkinson’s disease and other degenerative illnesses. 

“This is a revolutionary finding,” one researcher says. “This system plays a huge role in the health of the brain.” She describes the glymphatic system as like a dishwasher for the brain. “The brain is very active and so it produces a lot of junk that needs to be cleaned out.”

In hindsight, the system should have been noticed long ago. When the skull and head are dissected, the vessels are visible to the naked eye. But no one bothered to really look.

The vessels have also been implicated in autoimmune disease, such as multiple sclerosis. Researchers knew that the immune system has limited access to the brain. But at the same time, the immune system kept tabs on the brain’s status; no one knew exactly how. Some researchers theorize that the glymphatic system could be the conduit. In diseases like multiple sclerosis — where the body’s immune system attacks certain brain cells — the communication may go awry.

Recently, Harvard University researchers reported that glymphatic flow is significantly decreased in the period just before a migraine. The intense pain in these headaches is caused largely by inflamed nerves in the tissue that surrounds the brain. The authors of the study theorize that faulty clearance of molecular waste from the brain could trigger inflammation in these pain fibers.

One key to glymphatic performance seems to be sleep. At least in mice, the system processes twice as much fluid during sleep as it does during wakefulness. It’s possible that sleep dysfunction may contribute to Alzheimer’s and perhaps other brain illnesses: “You only clean your brain when you’re sleeping. This is probably an important reason that we sleep. You need time off from consciousness to do the housekeeping”.

It also appears that sleep position is crucial. In an upright position — someone who is sitting or standing — waste is removed much less efficiently. Sleeping on your stomach is also not very effective; sleeping on your back is somewhat better, while lying on your side appears to produce the best results. The reason for these differences might be related to the mechanical engineering of the lymphatic vessels and valves; the healthiest approach may be to move periodically while you sleep.

Sleep is probably not the only way to improve glymphatic flow. Omega-3 fatty acids and deep breathing may also improve glymphatic functioning. 

Not being a scientist, I can’t evaluate these studies, but it makes sense that brains produce a lot of junk that needs to be cleaned out. (And you didn’t think the President would come up in this post.)

The Real Building Blocks of the Universe (So Far)

Thales of Miletus is generally credited with being “the first philosopher in the Greek tradition [and] as the first individual in Western civilization known to have entertained and engaged in scientific philosophy” (Wikipedia). Less formally, he’s known as the ancient Greek who thought everything is made of water.

But that wasn’t a crazy idea at the time:

Thales [c. 624 – c. 546 BC] is recognized for breaking from the use of mythology to explain the world and the universe, and instead explaining natural objects and phenomena by theories and hypothesis, i.e. science. Almost all the other Pre-Socratic philosophers followed him in explaining nature as deriving from a unity of everything based on the existence of a single ultimate substance, instead of using mythological explanations. Aristotle reported Thales’ hypothesis that the originating principle of nature and the nature of matter was a single material: water (Wikipedia).

Jumping forward around 2,500 years, we’re still trying to figure out what everything is made of. If you’d asked me a few days ago, and given me a few seconds to think about it, I’d probably have said everything is made of very tiny particles like quarks and photons:


Fortunately, however, the scales have been lifted from my eyes. All it took was watching a lecture by a physicist named David Tong. It’s called “Quantum Fields: The Real Building Blocks of the Universe”. Here’s how he explains the situation on his University of Cambridge webpage:


We learn in school that the basic building blocks of matter are particles. In fact, we often continue to teach this in universities where we explain that quarks and electrons form the lego-bricks from which all matter is made.

But this statement hides a deeper truth. According to our best laws of physics, the fundamental building blocks of Nature are not discrete particles at all. Instead they are continuous fluid-like substances, spread throughout all of space. We call these objects fields.

The most familiar examples of fields are the electric and magnetic field. The ripples in these fields give rise to what we call light or, more generally, electromagnetic waves. The field [relating to a magnet is shown here].


From Fields to Particles

If you look closely enough at electromagnetic waves, you’ll find that they are made out of particles called photons. The ripples of the electric and magnetic fields get turned into particles when we include the effects of quantum mechanics.

But this same process is at play for all other particles that we know of. There exists, spread thinly throughout space, something called an electron field. Ripples of the electron field get tied up into a bundle of energy by quantum mechanics. And this bundle of energy is what we call an electron. Similarly, there is a quark field, and a gluon field, and Higgs boson field. Every particle your body — indeed, every particle in the Universe — is a tiny ripple of the underlying field, moulded into a particle by the machinery of quantum mechanics.


These fields fill the universe, even what seems to be empty space. All of the particles the physicists have identified are manifestations of these fields. In some sense, apparently, so are we. 

Prof. Tong gave his lecture at the Royal Institution in London in November. It’s an hour-long introduction to Quantum Field Theory for the general public. He’s an entertaining speaker and, as an added bonus, he looks and sounds a lot like the comedian John Oliver.

If you want to jump ahead a little, it’s about nine minutes in when he announces that:

The best theories we have tell us that the fundamental building blocks of nature are not particles but something much more nebulous and abstract. The fundamental building blocks of nature are fluid-like substances which are spread throughout the entire universe and ripple in strange and interesting ways. That’s the fundamental reality in which we live. These fluid-like substances, we have a name for, we call them “fields”.

Have fun. After this, you may never see the world in the same way.


(Hmm, notice how I didn’t mention You Know Who once? This should not suggest that anything is back to normal yet. Far from it.)

Good News: The 25th Amendment Can Be Invoked in 23 Days

Bad news: A man with a serious personality disorder will be sworn in as President on January 20th, only 23 days from now.

But as noted above, the new President will immediately become subject to the provisions of the 25th Amendment to the Constitution. That’s the amendment that allows the Vice-President to become President when the President dies or becomes “unable to discharge the powers and duties of his office” (unfortunately, of course, it’s still “his”).

Here’s the first paragraph of Section 4:

Whenever the Vice President and a majority of either the principal officers of the executive departments or of such other body as Congress may by law provide, transmit to the President pro tempore of the Senate and the Speaker of the House of Representatives their written declaration that the President is unable to discharge the powers and duties of his office, the Vice President shall immediately assume the powers and duties of the office as Acting President.

There is more to it than that, because the President can object to the Vice-President’s declaration. Congress would then decide the issue.

Granted, given the fact that the new President is being extremely careful to appoint people he trusts to his cabinet, it might be difficult for Vice President Pence to get the necessary signatures right away. He’d probably need to wait until at least one of the President’s appointments had been confirmed, but I’m sure the details could be worked out.

Next question: Will the new President be unable to perform his duties as required? That’s an easy one. The man is clearly suffering from a severe psychological disorder. (I mean, seriously.)

It didn’t get much attention, but three professors of psychiatry sent a letter to President Obama last month. They called for the next President to undergo “a full medical and neuropsychiatric evaluation” in order to see if he suffers from an incurable (!) illness called “Narcissistic Personality Disorder”. Professional ethics demand that psychiatrists not diagnose patients from afar, but is there any doubt that the President-elect is not a well person? From their letter:

Here … are the 9 criteria for “Narcissistic Personality Disorder”. If an individual has 5 out of the 9 they have a confirmed diagnosis of this illness…

“Summary : A pervasive pattern of grandiosity (in fantasy or behavior), need for admiration, and lack of empathy, beginning by early adulthood and present in a variety of contexts, as indicated by five (or more) of the following:

1. Has a grandiose sense of self-importance (e.g., exaggerates achievements and talents, expects to be recognized as superior without commensurate achievements)

2. Is preoccupied with fantasies of unlimited success, power, brilliance, beauty, or ideal love.

3. Believe that he or she is “special” and unique and can only be understood by, or should associate with other special or high-status people (or institutions)

4. Requires excessive admiration

5. Has a sense of entitlement

6. Is interpersonally exploitative

7. Lacks empathy: is unwilling to recognize or identify with the feelings and needs of others

8. Is often envious of others or believes that others are envious of him or her.

9. Shows arrogant, haughty behaviors or attitudes.”

Opinions may vary, but I give him roughly nine out of nine. 

The professors continue:

1. People with NPD are extremely sensitive and insecure. They psychologically require constant compliments and acknowledgement because they do not have their own internal self-esteem. They need to get it from others.

2. If someone does criticize them, … it triggers this deep and painful lack of self-esteem and they MUST lash out to relieve the pain of the criticism.

3. They have only two modes: They are either fully your friend and love you or you are their enemy and they will do everything to discredit you or humiliate you. They can’t help it. The pain of having someone in their circle who does not approve of them or acknowledge them, almost constantly, is too great.

4. There are only two ways to deal with someone with NPD, and they are both dangerous. There is no healthy way of interacting with someone with this affliction. If you criticize them they will lash out at you and if they have a great deal of power, that can be consequential. If you compliment them it only acts to increase the delusional and grandiose reality the sufferer has created, causing him to be even more reliant on constant and endless compliments and unwavering support.

5. Because they crave the attention and approval of others they develop great capacity to engage and entertain and can be quite charismatic, even to the point of developing a cult-like following.

6. Someone with NPD will NEVER get along with any member of the press or any media outlet that criticizes him.

7. Someone with NPD will NEVER hire (and will fire) anyone who criticizes him. Therefore, and because they believe they know better than almost everyone else, they have a very hard time listening and taking any advice.

In other words, the President of the United States will be psychologically armed and extremely dangerous as of high noon on January 20th. That’s when the Vice-President of the United States needs to begin the process of saving us from the Electoral College. Never put off until tomorrow what needs to be done today.


Bad news: Mike Pence, a rock-ribbed Republican jerk, would become President.

Good news: We’ve survived bastards like him before.

More good news: If Pence doesn’t immediately get the 25th Amendment rolling, see Article 2, Section 4, Impeachment. Even Congressional Republicans do their jobs sometimes.

Water, Water Everywhere? A Highly Surprising Graphic

If all the water in the world were collected and put next to the planet Earth, it would look like this:


After seeing this, it seems much more plausible that all our water came from comets and asteroids. It also makes our planet’s water seem even more precious.

There’s more here at NASA’s Astronomy Picture of the Day.

It’s Alright, Ma (I Was Only Bleeding)

Here’s one of those inventions that sounds too good to be true. From Suneris Inc.’s site:

Constantly experimenting with different natural materials in the lab as a young adult, Joe Landolina conceived an adhesive hemostatic gel composed of plant-based polymers that could adhere to a wound site and simultaneously support the natural clotting process.

In other words, you squeeze some of this stuff on an open wound and it stops the bleeding in seconds. In addition, it apparently grows new tissue.

Discovery News reported on this Star Trek-like technology three years ago (warning: video contains jokes and blood):

Vetigel is now being sold to veterinarians. Let’s hope it works well enough to be used one day on soldiers, accident victims and other human beings, including iconic bleeding rock stars:

As the Climate Changes, So Will Our Understanding

William Gail is a past president of the American Meteorological Society. He calls attention to an aspect of the global warming crisis I hadn’t really considered: climate change will mean that we’ll know less about the world.

Civilization’s understanding of Earth has expanded enormously in recent decades, making humanity safer and more prosperous. As the patterns that we have come to expect are disrupted by warming temperatures, we will face huge challenges feeding a growing population and prospering within our planet’s finite resources. New developments in science offer our best hope for keeping up, but this is by no means guaranteed.

Our grandchildren could grow up knowing less about the planet than we do today. This is not a legacy we want to leave them. Yet we are on the verge of ensuring this happens.

His op-ed article is here.

What Should Sleeping Beauty Say, Logically Speaking? (Part 2)

In yesterday’s post, I described the so-called “Sleeping Beauty Problem”. Mathematicians and philosophers have been debating this problem for the past 15 years (most recently in response to an article at the Quanta Magazine site). What should Sleeping Beauty say when she wakes up on Monday or Tuesday and is asked the following question about a coin flip that happened on Sunday: “What are the odds that the coin we flipped on Sunday came up heads?”.

To review: Sleeping Beauty doesn’t know what day it is when she wakes up or whether she’s already woken up during the experiment. But she is told that if the coin flip on Sunday came up heads, she’s only being awakened on Monday. If, however, the coin came up tails, she’s being awakened on both Monday and Tuesday. “Halfers” think the odds that the coin came up heads is 1/2. “Thirders” think the answer is 1/3.

Here’s the answer Pradeep Mutalik, the author of the Quanta article, gave in response to a whole lot of comments:

This is the crux of the idea: that there are two propositions in the Sleeping Beauty problem:

1) the probability of heads when the fair coin is tossed, which is obviously 1/2. This is the proposition modeled by halfers.
2) the probability of heads encountered later, which thanks to the experimental conditions that are asymmetric between heads and tails, is 1/3. This is the proposition modeled by thirders.

… the same problem statement can mean tossed if understood one way and encountered if interpreted another way.

Once you accept that there are two valid interpretations, the solution of the Sleeping Beauty problem can be expressed in one sentence:

A fair coin is tossed: The probability of it landing heads when tossed is ½; the probability of Sleeping Beauty encountering heads later, thanks to the asymmetric experimental conditions, is 1/3.

And that, in a nutshell, is all there is to it.

Mr. Mutalik also added this note in response to my own comment on his article, in which I came out in support of the 1/3 answer:

As in my reply to Rich, your answer is correct for the heads “encountered” probability. The heads “tossed” probability is, and remains ½ until SB learns the actual result of the coin toss.

The point of all this is to show that there is no incompatibility in the thirder and halfer arguments. The same person can simultaneously be both a halfer and a thirder.

As a new supporter of the thirder position, I’m not convinced by Mr. Mutalik’s response. As I wrote in the previous post, it’s clear that the odds of getting heads or tails when a coin is flipped are always 1/2 heads and 1/2 tails. That’s how coin flips work (putting aside the extremely rare occasions when they land on their edge and don’t fall either way). 

But the question presented to Sleeping Beauty is: “What are the odds that the coin flip came up heads?” Since she knows how the experiment is being conducted when she’s asked this question, shouldn’t she conclude that the odds are 1/3, not 1/2? After all, she knows that a coin that came up tails means this could be either Monday or Tuesday. If it came up heads, it can only be Monday. So the odds that the coin came up tails is twice as likely as the odds that it came up heads (i.e., 2/3 vs. 1/3).

It seems to me that asking Sleeping Beauty to ignore the information she’s been given about the experiment is asking her to give an answer she knows is incorrect. What a question means depends on its context. If the context in this case were simply: “Please explain how coin flips work. In particular, what are the odds that a fair, properly-executed coin flip will come up heads instead of tails, such as the coin flip we executed on Sunday?” In that context, the correct answer is obviously 1/2. Everybody should be a halfer when asked how coin flips work.

But that isn’t the context in which Sleeping Beauty is being asked to give an answer. She’s not being asked to explain how coin flips work in general. She understands that she’s involved in a bizarre, possibly unethical (the memory-destroying drug!) experiment and that the question she’s being asked is part of that experiment. She’s being asked what the odds are given her current situation. That’s why I think it’s more reasonable for Sleeping Beauty to be a thirder than a halfer. She should answer “1/3”. It’s twice as likely that the coin came up tails!

Whether she should be allowed to go back to sleep after giving the correct answer, so that she can later be awakened by a handsome young prince, or whether she should receive appropriate medical care and reacquire a normal sleeping pattern, is an ethical question, not a logical one, and beyond the scope of this post.