Evidence of the body’s waste system in the human brain
nih.gov
nih.gov
Another case of a small but valuable increment of research and nauseating treatment of the same by the spin department I guess.
> While it was initially believed that both the brain and meninges were devoid of lymphatic vasculature, a recent study by Antoine Louveau and Jonathan Kipnis at the University of Virginia, submitted in October 2014, and another confirming the discovery, by Aleksanteri Aspelund and Kari Alitalo at the University of Helsinki submitted in December 2014, identified and described the basic biology of the meningeal lymphatics using a combination of histological, live-imaging, and genetic tools.
I'm not sure whether these are the same entities?
And yes, these are the right thing.
Can someone explain why these vessels were never discovered during autopsies until now? Are they too thin, or transparent, or thought to have been something else, or the tubes become squished after death and therefore difficult to separate from other tissue, or what?
As to how the brain’s lymphatic vessels managed to escape notice all this time, Kipnis described them as “very well hidden” and noted that they follow a major blood vessel down into the sinuses, an area difficult to image. “It’s so close to the blood vessel, you just miss it,” he said. “If you don’t know what you’re after, you just miss it.”
http://neurosciencenews.com/lymphatic-system-brain-neurobiol...
It's entirely plausible to me that this has gone unnoticed for 200 years.
Two possibilities come to mind. First, he may have been studying a rare brain that had an enlarged system, and since he did not have preconceptions that what he found couldn't possibly be a component of the lymphatic system, he called it like he saw it. (It is also possible such brains were less rare back then or something. Many things have changed in our body's environments in the last 200 years. Random correlations abound.)
The other is that perhaps he was simply wrong. He saw something that he identified as a lymphatic component but was in fact something else. Future people didn't make the same mistake so the observation sank without a trace. 200 years later, the real and much-more-subtle lymphatic system was found.
[1] http://news.stanford.edu/news/2014/november/mystery-brain-im...
Video description:
Leonardo became obsessed with the heart in the latter period of his remarkable life. He made a prediction about the main blood vessel leaving the heart, the aorta. He had figured out how the flow of blood out of the heart actually closes the aortic valve.
Leonardo had no way of testing it and no way of seeing inside a working heart. For centuries no one else even speculated. But in the last 50 years technology has finally been invented to show that he was absolutely right.
And even practicing surgeons. Cadaver studies are hugely important for training surgeons how to implant new or new-to-the-surgeon medical devices.
Lymphatic vessels are part of the body’s circulatory system. In most of the body they run alongside blood vessels.
it's somewhat surprising (in hindsight I admit) that no-one thought to look for them there before.
How about you have a peek at the research article, think away the colors from the antibody staining and see if you still consider it strange that it could go undiscovered.
The things in question are appropriately measured on a micrometer scale, fragile to match and tightly tangled up with similar things inside jelly. And needless to say they don't come with helpful colored plastic hulls or developer defined object type annotation for inspection.
Because comp sci has an arrogance problem that rivals that of doctors?
Nailed it!
luckily, i had a penicillin script that I didnt finish, and after the first pill the sore throat (and the fever) broke within hours.
later when talking to my brother (who is a doctor), he told me the problem, one that he had also. When he gave the step test, it came back negative even when he knew it was positive. an older attending told him that you have to really get it in there, rub it around for a long time in order for it to work, where most just do a quick swipe.
another such example was someone came to the ER with chest pain. they didnt detect anything in the blood test so they were going to send him home. my brother refused and ordered more tests. turns out he was in the middle of having a heart attack when they were going to send him home, because ... the test.
the moral to the story is, many doctors blindly rely on tests and whats in the book, and disregard contradicting evidence.
Also, shame on you for not finishing your antibiotic prescription. Always finish your antibiotic! If you don't finish, you run the risk of a resurgence of the infection, except this time with bacteria resistant to the antibiotic you failed to finish.
If you really feel like you need a private stash of antibiotic, buy amoxicillin for aquarium fish instead of saving portions of old prescriptions. And make sure you weigh yourself and appropriately calculate the mg/kg dosage before using it.
(I understand that this is hypocritical to shame someone for not finishing a prescription antibiotic and also to recommend misuse of veterinary antibiotics.)
Opinions differ:
https://www.theguardian.com/society/2017/jul/26/rule-patient...
Keep in mind that society has chosen to have physicians carry social and often moral authority. They are the modern priests and priestesses of our secular world.
What stings when a physician is impatient or misses something obvious is the disrespect people feel because of the physician's venerated status. It's as if a person of faith is visiting a Bishop and the Bishop mutters a profanity during the blessing.
The irritation and accusations of arrogance toward physicians that are found in this thread are (if read carefully) reflections of the unique, clergy-like role that physicians play. A physician's opinion can get you decades of workers comp or can deny it to you, it can make you feel responsible for a health problem or vindicated, it can result in the removal of pain or the continuation of it. Physicians let some people get high every day on any number of drugs, declare others bad surgical candidates, and instill (or withhold) hope in those whose life hangs in the balance.
It's a deeply moral role, and the trend toward free healthcare for all is analogous to publishing the bible in languages besides Latin. Physicians are gatekeepers to redemption and this makes some people very angry.
A mechanic was removing a cylinder-head from the motor of a Harley motorcycle when he spotted a well-known cardiologist in his shop.
The cardiologist was there waiting for the service manager to come and take a look at his bike when the mechanic shouted across the garage.
"Hey, Doc, want to take a look at this?"
The cardiologist, a bit surprised, walked over to where the mechanic was working on the motorcycle.
The mechanic straightened up, wiped his hands on a rag and asked, "So Doc, look at this engine. I open its' heart, take the valves out, repair any damage, and then put them back in, and when I finish, it works just like new. So how come I make $39,675 a year and you get the really big bucks ($1,695,759) when you and I are doing basically the same work?"
The cardiologist paused, smiled and leaned over, then whispered to the mechanic.....
"Try doing it with the engine running."
[1] Found a better version than the one I was screwing up in the retelling at https://www.neowin.net/forum/topic/983804-joke-harley-mechan...
How are they missing features that are visible with the human eye? I find it incredible.
Also, XKCD meme is the tiredest meme around.
PS: I work in an Anatomy Department.
Anecdotally, whenever I've had that droopy-eyelids nodding off sensation, when it passes it has always felt like the tiredness is literally draining from my brain.
with a nice MRI of fluid being pumped around. Though I think a different system to the one in this article.
Jellyfish have no brain, but also sleep. So that can't be the reason. (It might happen then anyway, but it's not the fundamental reason.)
They don't have a BRAIN but they have nervous system. A nervous system creates waste and that waste needs to be reclaimed. What's a brain? An exotic collection of neurons... that create waste.
http://neurodojo.blogspot.com/2009/05/jellyfish-nervous-syst...
>Instead, jellyfish have a ring nervous system, located along the margin of the bell. There is definitely a concentration of neurons in that location (although it contains relatively few neurons compared to other animals). Plus, those neurons do serve as an active relay and processing station for sensory and motor activity. Those are two of the main things that central nervous systems do, so there seems to be no good reason to deny that jellyfish have a central nervous system. (Picture from Mackie and Meech, 2000.)
https://en.wikipedia.org/wiki/List_of_animals_by_number_of_n...
Jellyfish: 5,600 neurons.
Box jellyfish: 8,700-17,500 neurons.
Human: 86,000,000,000 neurons.
Notice jellyfish do not have "zero" neurons.
Further, from the wiki: "Not all animals have neurons; Trichoplax and sponges lack nerve cells altogether."
https://www.quora.com/Do-sponges-sleep
"Do sponges sleep?"
"As noted by others, sponges lack nervous systems, [...] sponges don't have nerve cells at all. So NO they don't 'sleep" in any manner similar to other animals."
What prevents one of the reasons we sleep to be absent from the set of reasons jellyfish sleep?
Also, wouldn't it be surprising if a behavior as complex as sleeping had only one reason, or if the main reason today would be anything like the main reason back in the days were the common ancestor between us and jellyfish lived? And so, shouldn't we expect that we sleep for different reasons?
--- Bill Gates 1982mya
[1]: https://www.google.com/amp/s/amp.theguardian.com/science/201...
[2]: https://www.nobelprize.org/nobel_prizes/medicine/laureates/2...
"While it is never safe to affirm that the future of Physical Science has no marvels in store even more astonishing than those of the past, it seems probable that most of the grand underlying principles have been firmly established and that further advances are to be sought chiefly in the rigorous application of these principles to all the phenomena which come under our notice. It is here that the science of measurement shows its importance — where quantitative work is more to be desired than qualitative work. An eminent physicist remarked that the future truths of physical science are to be looked for in the sixth place of decimals."
Albert Michelson is the Michelson of the Michelson-Morley experiment that showed that the speed of light was identical from all perspectives - a discovery that was soon to completely revolutionize our understanding and notion of physics. The comment was also made shortly before quantum mechanics would really begin to be delved into, further revolutionizing physics.
We only know what we know. And that's all we know - until we know more. In the case of the brain in particular we have practically zero causal and holistic understanding. And much of what we do know has been driven by pharmacological profit motive, which doesn't necessarily yield the most objective science and certainly constraints it in any case. Ultimately, I'd be rather more surprised if there are not a vast number of fundamental discoveries yet to be made!
This is not the only 'how can we not know this' thing which happens, I read a few years back that fundamental nervous system linkages (as in, the actual nerves themselves) of the clitoris had not been mapped in the 20th century because nobody felt like it mattered enough until women anatomists started looking more carefully at the cadavers...
I was wondering whether the stuff that this new lymphatic vessels carry were still known to be dumped off the brain by blood or otherwise, or were assumed to remain in or to be used up by the brain.
Intracellular adenosine which builds up over the course of waking day may be uptaken by brain lymphatics but would play a small part if they are inside the dura as this states. In fact, given clearance rate that is suggested from the article by way of position and size, they likely contribute very minimally to any clearance function if at all(unless further discoveries show intra brain lymphatics)