
Brains Sweep Themselves Clean of Toxins During Sleep (2013) - Practicality
http://www.npr.org/sections/health-shots/2013/10/18/236211811/brains-sweep-themselves-clean-of-toxins-during-sleep
======
roymurdock
My friends and I were up late on a road trip once. We started to argue about
how long it would take someone to die from lack of sleep.

Initially, I held the position that sleep was probably more important than
eating food, and that you would die from sleep deprivation before you died
from starvation. We looked it up, and learned about a disease called _fatal
familial insomnia_. A mutated protein causes the onset of permanent insomnia,
and there is no cure. It affects about 100 individuals worldwide. [1]

The average life expectancy of a patient is 18 months after the onset of
symptoms. The first 9 months is a worsening case of insomnia, where the
patient will experience paranoia, panic attacks, and hallucinations. Sleeping
pills and barbiturates have been shown to worsen the clinical manifestations
and hasten the onset of the disease. The individual then becomes completely
unable to sleep, and will enter a state of dementia before becoming completely
mute and unresponsive. This second state of permanent insomnia lasts for 9
months.

So ultimately, we learned that you can go for 9 months without sleeping before
you die. I'm not sure at what point you'll suffer irreversible brain damage,
but that was an interesting finding for me nonetheless.

[1]
[https://en.wikipedia.org/wiki/Fatal_familial_insomnia](https://en.wikipedia.org/wiki/Fatal_familial_insomnia)

~~~
mratzloff
It sounds like the brain is running something like a defragmentation routine
every night. If it doesn't complete, your thoughts become more and more
incoherent.

~~~
alfonsoperez
Once I had some strong personal issues and spent a full 6-7 days without
getting any sleep. At that point I was convinced that my neighbors (Pakistani)
were from IS, I even started an investigation (using some tactics you can
guess) in order to find evidence and was already seeking political asylum in
the US. Now I think about it and it's even funny, but hell.

~~~
chipsy
New hypothesis: The reason the U.S. leans conservative relative to other
countries is lack of sleep.

~~~
sitkack
You might be able to track this down using public data.

------
david_shaw
The engineer in me has to wonder: is this something we can synthesize?

If it were possible to induce this "dishwasher-like" surge of cerebrospinal
fluid in the brain during waking hours, would we be able to live off of
significantly less (or no) sleep?

I'm not saying that it's necessarily a good idea, but it would have a plethora
of practical applications -- pilots, truckers, etc. would be able to stay
awake in a healthful way, rather than by ingesting stimulants.

I've been interested in the science of sleep for a while -- I wrote a side
project, [http://sleepyti.me](http://sleepyti.me), that actually gets quite a
bit of traffic -- but neuroscience is mostly lost on me.

~~~
JoshTriplett
It seems rather likely that other neurological functions occur during that
time as well. Unless we have the ability to simulate all of them, we shouldn't
assume that the ones we ignore aren't important.

It would be especially harmful if we ended up suppressing the processes that
make you feel sleepy when you need sleep, while the harmful effects of
sleeplessness remained.

~~~
qiqing
(Former neuroscientist here.) This is true of caffeine, for example, which is
an adenosine analog (e.g. it has a similar shape and fits into the same
receptors). Adenosine is a signal to a cell that it's running low in energy.
Caffeine competitively binds to the spots on receptors where adenosine goes,
effectively preventing the cell from communicating its low energy state.

Now here's the kicker. When your body builds 'tolerance' for caffeine, what
this usually means* is the post-synaptic cell adjusts how much adenosine it's
pumping out so that the "I'm tired" signal can cut through the caffeine. And
when you go through caffeine withdrawal, it takes a while for those levels to
re-adjust to normal.

* in the brain. Caffeine also has effects on your digestive tract, blood pressure, and some other non-brain parts. :)

Edit: corrected cAMP -> adenosine (simple recall error from a lecture that was
9 years ago). The gist of the reply remains the same.

~~~
lvs
This is incorrect information. (... Like so many biology/chemistry comments I
see on HN.)

Caffeine is more like an adenine analog, not a cAMP (3'-5' cyclic adenosine
monophosphate) analog. It binds adenosine receptors, not primarily cAMP
receptors. It has indirect effects on cAMP, but I am not aware of direct ones.
Also, your description of cAMP signaling sounds confused, since cAMP is an
intracellular second messenger. I am not aware of an extracellular retrograde
signaling process for this molecule.

Sorry, and your implication that cAMP is a byproduct of ATP consumption is
totally wrong. cAMP is synthesized directly from ATP, a reaction catalyzed by
the regulated enzyme adenylate cyclase.

~~~
qiqing
Thank you for the correction. I mis-remembered a minor detail from a lecture
that was 9 years ago, and have find/replaced cAMP -> adenosine in the above
post. The gist of the post, though, remains the same. That is, caffeine
competitively inhibits receptors that gate ion channels, and the mechanism of
tolerance is an increase in the concentration of the thing that it
competitively binds.

(My thesis was on auditory cognition and I haven't touched ion channel
biophysics in that long. I have a long-ago memory that adenosine (now
corrected) operated as a retrograde transmitter, though since I'm probably not
going to spend my afternoon looking for the citations, I'll delete as well for
now. Not because I believe it's wrong, just that I can't immediately back it
up.)

Are you still doing research yourself or have you left for startup land like
most of HN?

~~~
lvs
Thanks for making your corrections as well. Yes, I am in research, and I
mostly come here for what's new in Python, learning algorithms, and data
analysis. As an aside, it's tough to wade through the "startup land" and
personal health advice and keep a straight face in all honesty, but there are
few other places that aggregate the things I'm interested in on the computing
side of things. An "HN" with users that specialize in bioscience would be very
interesting, but I don't know of one with any level of seriousness/activity.

~~~
charles2013
datatau [0] might be worth checking out, if you're not familiar.

since bioscience isn't on my radar i'm not sure if you'd find anything useful
there, however, it feels like a more concentrated version of HN which
specializes in some of the other stuff that interests you (e.g. learning
algos, data analysis, etc.).

[0] [http://www.datatau.com/](http://www.datatau.com/)

------
roflmyeggo
Yet another reason to get a good nights sleep.

Many of these metabolic degradation products (not just beta-amyloid) of
neuronal cell activities should readily be cleared quickly and efficiently
from the interstitial space of the brain due to the highly sensitive nature of
neuronal cells to their environment.

Some negative effects documented from these byproducts include: negatively
effecting synaptic transmission[1], decreasing cytosolic Ca2+
concentrations[2] (Ca2+ is one of the final players in the triggering the
release of neurotransmitters into the synapse between neurons to facilitate
messages), and irreversible neuronal injury[3].

[1] - K. Parameshwaran, M. Dhanasekaran, V. Suppiramaniam, Amyloid beta
peptides and glutamatergic synaptic dysregulation. Exp. Neurol. 210, 7–13
(2008)

[2] - K. V. Kuchibhotla, S. T. Goldman, C. R. Lattarulo, H. Y. Wu, B. T.
Hyman, B. J. Bacskai, Abeta plaques lead to aberrant regulation of calcium
homeostasis in vivo resulting in structural and functional disruption of
neuronal networks. Neuron 59, 214–225 (2008)

[3] - M. P. Mattson, Calcium and neuronal injury in Alzheimer’s disease.
Contributions of beta-amyloid precursor protein mismetabolism, free radicals,
and metabolic compromise. Ann. N. Y. Acad. Sci. 747, 50–76 (1994)

------
akilism
I just read two really good neuroscience articles over on nautil.us. This
stuff is super interesting.

[http://nautil.us/issue/27/dark-matter/heres-why-your-
brain-s...](http://nautil.us/issue/27/dark-matter/heres-why-your-brain-seems-
mostly-dormant)

[http://nautil.us/issue/27/dark-matter/the-neurons-secret-
par...](http://nautil.us/issue/27/dark-matter/the-neurons-secret-partner)

------
pizza
I can't help but imagine that if this is the case then increased water intake
(prior to bed or simply throughout the day) would help intercellular water
flow. Anyone know anything about drinking water improving sleep quality? Or
generally well-informed sources that describe which bodily processes improve
when you drink more water?

~~~
Mz
I don't have sources at my fingertips. I have done a lot of reading. This
process of clearing wastes from the brain during sleep is not news to me. They
are talking about the lymphatic system, which is the general waste removal
system for the body. For your musculoskeletal system, lymph flow increases
dramatically with physical activity. So walking more is really helpful. But
the brain is on a separate system and lymph gets cleared by sleep.

I have a serious incurable condition that interferes with, among other things,
oils and salts in my body. What I have figured out over the past 14-ish years
(since getting diagnosed) is that hydration is not just about how much fluid
you take in. Just like you can oil something to protect it from water, oil in
the body helps keep water in. And salt and other electrolytes also matter.

There are also other brain chemicals involved in helping modulate the waking
and sleeping cycle of the brain, chiefly melatonin and co-q-10. I took lots
and lots of co-q-10 to heal my sleep disordered brain after getting off the
boatload of prescription drugs that fried it and messed up my ability to
sleep.

I sleep a lot better than I used to. I am better hydrated than I used to be.
But hydration is not merely a matter of drinking water. There are a lot of
other chemical things going on there. But I would agree that proper hydration
helps (with sleep, brain function, and general lymphatic processes). Water
alone does not get you to proper hydration.

~~~
gima
What is this condition that you have which has to do with oils and salts? Any
links and resources would be of interest to me.

~~~
Mz
My official diagnosis is atypical cystic fibrosis.

------
clumsysmurf
Its possible that sleeping on your side allows the glymphatic pathway to clear
waste more efficiently.

[http://www.futurity.org/side-sleeping-
brains-979872/](http://www.futurity.org/side-sleeping-brains-979872/)

------
omarchowdhury
All is one; during sleep the undistracted soul is absorbed into this unity; in
the waking state, being distracted, it distinguishes diverse beings. _(Chuang
Tzu)_

~~~
orik
I thought you were TempleOS at first glance.

------
rebootthesystem
Many years ago, during a stupid-er time in my life, I stayed up three nights
in a row.

I was working on a robotics paper to present at a conference. My first. It was
a massive project and things had fallen behind schedule. With just three days
left until I was supposed to be on a plane I had no choice but to work on the
thing continuously and get it done.

It was a solid three days of writing code and building/testing boards. I got
done and packed with a couple of hours to spare before having to go to the
airport. For some reason I could not sleep on the flight from Los Angeles to
Seattle.

Once I got to the room at the hotel I pretty much collapsed on the bed. My
talk was scheduled for the next morning. I figured I could sleep a solid 12
hours and have a couple to get ready for the talk/presentation.

Somewhere in the middle of the night I woke up. I have no clue how long I
slept up to that point. I had lost all sense of time. I went to the bathroom.
And that's when the nightmare started.

I washed my face and almost immediately my ears started to buzz. It was
something like a 1kHz sine wave. It started at a low level and got louder and
louder. Scary.

At a certain point, my field of vision started to turn milky white. The tone
got louder and all I could see was a bright white light engulfing my entire
field of view.

I was blind and deaf and in the worst possible circumstances I could imagine.

I have no clue how long it all lasted. It felt like somewhere around 15
minutes. It could have been just thirty seconds but I had no sense of time and
I was freaking out. All I could do was sit on the bathroom floor, hold on to
something and think through the worst possible scenarios.

After what I guess was about fifteen minutes my vision started to slowly come
back and the tone started to fade away. That must have taken another 5 to 15
minutes. I was drenched in sweat and scared like I had never been in my life.
I've never done drugs or alcohol. I imagined this had to be like a grade-A
drug addict overdose experience, or worst.

All I could do was go back to sleep after that. I was exhausted.

The next day I asked to have my talk re-scheduled and went to see a doctor. He
told me I was an idiot and lucky not to have ended-up in the ER with brain
damage.

That was the last time I worked on anything overnight.

I know tech companies have a culture of working long hours to get things done.
Be sure you are not killing yourself to crank out another 100 lines of
meaningless code. The world can wait. And if your VC's don't understand you'd
like to live a long an healthy life, well, fuck them.

------
alexholehouse
Related discussion from a few weeks ago;

[https://news.ycombinator.com/item?id=9895094](https://news.ycombinator.com/item?id=9895094)

------
johndevor
I'd be curious to know if anything similar happens during meditation.

I often feel just as refreshed from meditating briefly as I do from a quick
nap.

------
saalweachter
The claim may or may not be true, but for me the word "toxins" has been so
thoroughly poisoned by woo that I get a knee-jerk reaction just reading the
title. The bar for anyone talking about cleansing toxins is like 200% higher
because of all the bullshit that's been spouted over the last few decades.

~~~
ksenzee
I think we can trust a professor of neurosurgery at the University of
Rochester not to be spouting woo in her study in _Science_.

~~~
DanBC
Of course we can. The fact that a trustworthy document from a real scientist
in a real journal is initially seen as less reputable because a journalist
uses the word toxins shows how devalued the word has become.

------
stdgy
The brain continues to fascinate. I wonder how the brain acts while under
anesthesia or induced to sleep through sleep aids? Is it different than
naturally falling asleep?

More particularly, it sounds like brain cells (At least in mice) shrink during
sleep and then enlarge during wakeful consciousness. That shrinking mechanism
may play a role in the cerebrospinal fluid recycling/cleaning process, which
itself may play a role in ridding the brain of harmful plaques. Does an
Alzheimer's patient not show the same level of growth and shrinkage? Could
forced sleep improve their outcomes? (IE: Could forced sleep lead to a more
normal growth/shrink cycle?)

I am, unfortunately, ignorant on most of the medical science at play here. Any
biologists, doctors or hobbyists have any thoughts?

~~~
qiqing
Former neuroscientist here (though I did not work directly on Alzheimer's or
sleep).

Anesthesia and sleep are different states, though there are some similarities.
Here's a figure that illustrates what 'typical' EEG looks like in these
various states:
[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3162622/figure/F...](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3162622/figure/F1/)

A smattering of other differences off the top of my head: you can feel pain
when you're asleep, but not under anesthesia. It is possible to wake up a
sleeping subject or patient with sounds or shaking, but not one under
anesthesia. Also you'll feel refreshed after you sleep, but not after
anesthesia.

~~~
XorNot
_Also you 'll feel refreshed after you sleep, but not after anesthesia._

When I had general anesthesia for my wisdom teeth I definitely felt refreshed
afterwards. I'm wondering if this idea isn't so well grounded, since we mostly
anesthetize and then do violent surgery on people - and so you mostly wake up
feeling _that_.

------
vlunkr
It's fascinating to me that we still don't know why we sleep. We spend 1/3 of
our lives in a self induced coma-like state and we aren't sure why, except
that if you don't you start to go crazy. It will be interesting to see how
this develops!

------
tim333
There's a nice gif on Wikipedia showing something like fluid flow in question:

[https://en.wikipedia.org/wiki/Cerebrospinal_fluid#Circulatio...](https://en.wikipedia.org/wiki/Cerebrospinal_fluid#Circulation)

------
brad3378
I have a harder time controlling my appetite if I don't get enough sleep.

Could these toxins be related?

~~~
Strom
Perhaps, as serotonin does regulate both sleep & appetite.

------
asciimo
>If this proves to be true in humans as well...

Wake me up when they publish _that_ paper.

------
lxfontes
brain: longest garbage collection cycle ever

------
cthyon
Does anyone know if there is research about whether this at all impacts/plays
a part in causing dreams?

------
pwagle
Has anyone determined which stages of sleep this occurs?

------
jeffdavis
So why does a lion need to sleep for 18 hours then?

------
carsongross
WHY? WHY IN GODS NAME?!?!

Why would such a preposterously dangerous state, complete defenselessness, not
be engineered around by darwinian pressure?!?

~~~
gress
Because it isn't.

------
bjd2385
This is fascinating!

------
rudolf0
>In Guantanamo they kept prisoners awake 11 days

Somewhat off-topic, but how could anyone possibly argue this is not torture?

~~~
Kenji
Is anyone arguing that torture is not something that happens in Guantanamo? By
now it should be common knowledge that it's a torture camp. Obama promised to
shut it down but he didn't.

~~~
rudolf0
I don't think anyone on HN has argued that, but many people in the general
public still insist that "enhanced interrogation" like what's done in
Guantanamo is not actually torture. Or at least they used to, until Obama
finally admitted people have been tortured; though some still insist it isn't
torture.

My question was more hypothetical. That seems like the very definition of
torture.

~~~
georgemcbay
Those people know it is really torture, they are just able to handwave it away
because the people it is happening to believe in a slightly different god than
they do.

