
Evidence of the body’s waste system in the human brain - dxbydt
https://www.nih.gov/news-events/news-releases/nih-researchers-uncover-drain-pipes-our-brains
======
etiam
At first I was incredulous that they would make this claim, since it makes it
appear they either failed to follow the literature enough to notice other
researchers made the remarkable _discovery_ of this system three years ago, or
are trying history revisionism to claim that discovery as their own. But I
guess the operative word here is "human". The original research actually gets
a small mention in the text body.

Another case of a small but valuable increment of research and nauseating
treatment of the same by the spin department I guess.

~~~
adaml_623
I would be helpful to supply a link to the research from 3 years ago that you
are mentioning.

~~~
dom0
[https://en.wikipedia.org/wiki/Meningeal_lymphatic_vessels](https://en.wikipedia.org/wiki/Meningeal_lymphatic_vessels)

> 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?

~~~
etiam
Fair point adaml_623.

And yes, these are the right thing.

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mysterypie
> _the team discovered lymphatic vessels in the dura, the leathery outer
> coating of the brain_

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?

~~~
Boothroid
I wonder the same thing. Not to be snarky, but is there something faulty about
medics or human biologists?! Why do I have a feeling that if we deployed
computer scientists at medical research we would get a better result? I can
accept that at the lower level things get fiendishly complex, but surely at a
macro level like this it's just a case of diligent analysis?

~~~
_jal
> Why do I have a feeling that if we deployed computer scientists at medical
> research we would get a better result?

Because comp sci has an arrogance problem that rivals that of doctors?

~~~
graphitezepp
The only difference (from my perspective of course) is comp sci arrogance is
directed towards our field and associated methodologies, principles, etc.
Doctors direct their arrogance towards themselves.

~~~
oddlyaromatic
This generalization is pretty large and may itself be an example of arrogance.
But I think maybe it's just the brevity of your comment that gives this
impression.

~~~
graphitezepp
Thanks for being charitable, I did not mean to imply that what I claim many
comp sci people do is any better or less arrogant, just different.

~~~
oddlyaromatic
It implies you know what doctors do about as well as you know what comp sci
people do, by virtue of comparing the two. The comp sci part is at risk of
taking your anecdotal experience as too representative of the whole. The
doctor part is (presumably) at risk of relying on stereotypes about doctors
having "God complexes" ... So to get to an effective general comparison would
be quite difficult without more accurate data. Buuut if we see ourselves as
smart computer people, maybe we think more highly of our own inferences than
they deserve. I would expect doctors' arrogance has a lot to do with their
training and respect for their processes and practices as being highly
reliable and advanced. Rather than them personally just having a talent for
doctoring.

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kensai
This one, together with the original rodent observation in 2015, is one of the
few "macroscopic" observations in anatomy the last decades. Since most of the
details of human and higher mammal anatomy have already been described, it is
rather rare and outstanding to make such new, remarkable observations.

PS: I work in an Anatomy Department.

~~~
amelius
I'm not a biologist, but can't this type of discovery be made by doing e.g.
RNA-Seq analysis of cells in different parts of the body? I can imagine that
every type of cell has a unique fingerprint, and lymphatic cells would be
easily identified when sampled in the brain this way.

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blubb-fish
This is very interesting for martial arts practitioners. It's highly plausible
that this waste system is the missing link between Parkinson and Alzheimer and
concussions due to head strikes. I'd assume that a strike to the head will -
if severe enough - first impair the dura mater. This might impair the waste
system and by that facilitate inflammations in the long run.

~~~
e40
I wonder what the mechanism is for non-concussed people with Parkinson's and
Alzheimer's? Is it related to the dura?

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ponco
That was exceptionally easy to digest as someone with very limited medical /
bio knowledge

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ruytlm
Interesting stuff, though I could have sworn I'd seen something similar
before, to do with the waste draining being one of the reasons we need sleep
(i.e. the body needs time to drain the accumulated waste products).

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.

~~~
ars
> being one of the reasons we need sleep

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.)

~~~
katastic
You guys keep saying that silly myth.

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...](http://neurodojo.blogspot.com/2009/05/jellyfish-nervous-system-myth-
busted.html)

>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...](https://en.wikipedia.org/wiki/List_of_animals_by_number_of_neurons)

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](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."

~~~
k__
It could also be that they don't sleep in the sense of humans.

~~~
Schizotypy
This seems to have flown over your head, but humans fall into that "other
animals" category

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kingkawn
Lots of disbelief in comments here, having done dissections I think it is
entirely believable that a structure this subtle could escape definition.
Dissection is not trivial.

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ggm
Am I alone in finding it stunning that it's 2017 and we can still discover new
anatomy? How can this not have been (re)discovered?

~~~
indubitable
Looking at this abstractly, there is a fun quote from Albert Michelson in
1894:

 _" 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!

~~~
ggm
I'm making a comment about gross anatomical structure. Not "where is the seat
of consciousness" but "this thing here? its a lymph tube" -thats a single,
simple gross morphological observation: tubes have walls. tubes have
boundaries.

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...

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djohnston
I hope this will lead to new targets for neurodegenerative proteinopathies.

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mebebil
Haven't read it just replying to the headline. I think it is amazing that how
a systemic approach to medicine could affect modern medicine. Defining the
boundary and the inputs/outputs are the most important aspect of understanding
any system.

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.

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johnvega
Great example that attention to details is important, and that great
discoveries can be just around the corner, so to speak.

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wiz21c
Can this mean that if one has a lot of stress, then its brain makes a lot of
waste which pollute the lymph and thus affects the immune system ? ('cos it's
well known that stressed people get sick quicker)

~~~
robbiep
Stress is a factor of hormones and metabolic factors. Brain has constant
metabolic consumption whether awake or asleep. Endocrine functions of brain
are carried out by release of hormones directly into portal (venous) systems.

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)

~~~
wiz21c
D*mn, that's what I call an answer. Thank you very much !

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amelius
Is it more active during sleep?

~~~
Schizotypy
I think sleep studies tracking lymphatic activity will be coming soon. At
least I would hope

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amai
See also
[https://news.ycombinator.com/item?id=13327056](https://news.ycombinator.com/item?id=13327056)

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noiv
Evidence of the brain’s waste system would be equally appreciated.

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k__
Does this mean we get medication that will clean up the brain?

