<p>The so-called glymphatic system, pump washing the brain with cerebrospinal fluid during sleep, has already been mentioned in answer to the SE question "Do you need to sleep every night?" It seems more than just a memory cleanup process as if on a computer, but "has significant implications for treating 'dirty brain diseases like Alzheimer's" and understanding it "is a critical first step in efforts to modulate this system and make it work more efficiently" (Maiken Nedergaard). That should go towards answering Q2, at least if such interventions take place in the waking state at the experimental stage. </p>

<p>Another recent report concerns brain cells known as microglia, which also play a role in mopping up neurotoxic brain waste such as beta-amyloids.  In addition they monitor the growth of synapses and prune connections between neurons so that the brain can refine its circuits and conserve resources, particularly during adolescence. Relevant maybe, as this is a period in life known for prolonged sleep. Some research on mice suggests a preference on the part of microglia for carrying out their work when the organism is in darkness. Hyperactive microglia however are conjectured to be implicated in Alzheimer's by stripping too many synapses when these are inadvertently tagged by the brain for destruction.</p>

<p>References:</p>

<p>"To Sleep, Perchance to Clean. Study* reveals brain takes out the trash while we sleep" University of Rochester News Room 17 Oct 2013</p>

<p>*Nedergaard M (corresponding author) et al "Sleep drives metabolite clearance from the adult brain" Science 18 Oct 2013</p>

<p>"The Mind Minders - a fertile, flexible brain couldn't live without its roving band of caretakers". New Scientist, 12 Oct 2013.</p>

CC BY-SA 3.0
2014-04-18T15:50:00.680Z
2014-04-18T15:50:00.680Z
Wanderlust
<p>There has been studies that shown that cerebrospinal fluid's circulation in the brain is dramatically(20x) increased during sleep. It is believed that <strong>during sleep, cerebrospinal fluid circulation helps clear out toxic by products of brain metabolism.</strong></p>

<blockquote>
  <p>As a result, the cerebrospinal fluid could not only flow more freely
  but it could also reach further into the brain. In an awake brain, it
  would flow only along the brain’s surface. Indeed, the awake flow was
  a mere 5 percent of the sleep flow. In a sleeping brain, waste was
  being cleared two times faster. “We saw almost no inflow of
  cerebrospinal fluid into the brain when the mice were awake, but
  <strong>then when we anesthetized them,</strong> it started flowing. It’s such a big difference</p>
</blockquote>

<p><a href="http://www.nytimes.com/2014/01/12/opinion/sunday/goodnight-sleep-clean.html?_r=0" rel="nofollow">http://www.nytimes.com/2014/01/12/opinion/sunday/goodnight-sleep-clean.html?_r=0</a></p>

<p><a href="http://www.nih.gov/researchmatters/october2013/10282013clear.htm" rel="nofollow">http://www.nih.gov/researchmatters/october2013/10282013clear.htm</a></p>

<p>Just a guess - if anesthesia improves cerebrospinal fluid flow, maybe then a combination of <a href="http://en.wikipedia.org/wiki/Isolation_tank" rel="nofollow">isolation/sensory deprivation tank</a>and anesthesia  would help achieve a cleansing effect? Either way, it does not appear that a human can be running around and working during such cleanup.</p>

CC BY-SA 3.0
2014-04-22T13:38:09.397Z
2014-04-22T13:38:09.397Z
Alex Stone
<p>Some time ago I <a href="https://cogsci.stackexchange.com/questions/3675/what-is-the-difference-between-drug-withdrawal-and-sleep-deprivation-effects">opened a question comparing drug withdrawal and sleep deprivation symptoms</a>.</p>

<p>In fact, my main objective for that question was to know if there was by any chance, a possibility to live without sleeping.</p>

<p>I got a good answer for the “Why we need sleep?” question, mentioning all the injuries that its deprivation causes.</p>

<p>So here are my current questions :</p>

<ol>
<li>What really happens in our brain during sleep that makes us feel much more "light" when we wake up and that its deprivation kills us? Is it memory cleanup?</li>
<li>Is there any research done on the reproduction of those “cleanup” processes without sleeping?</li>
</ol>

CC BY-SA 3.0
2014-03-16T17:28:17.990Z
yea, but what exacly in sleep / medidation / yoga, make that happen ? imagine you could identify it and reproduce it by just thinking (something like inner procedure activation - dunno if that concept even exists or how its called)
Enoque Duarte
<cognitive-psychology><sleep>
Is it possible to induce the processes that occur during sleep such as memory "garbage collection" without actually sleeping?
Enoque Duarte
# Is it possible to induce the processes that occur during sleep such as memory "garbage collection" without actually sleeping?

(Asked by: username_0 on 2014-03-15)

Some time ago I [opened a question comparing drug withdrawal and sleep deprivation symptoms](https://cogsci.stackexchange.com/questions/3675/what-is-the-difference-between-drug-withdrawal-and-sleep-deprivation-effects).

In fact, my main objective for that question was to know if there was by any chance, a possibility to live without sleeping.

I got a good answer for the “Why we need sleep?” question, mentioning all the injuries that its deprivation causes.

So here are my current questions :

1. What really happens in our brain during sleep that makes us feel much more "light" when we wake up and that its deprivation kills us? Is it memory cleanup?
2. Is there any research done on the reproduction of those “cleanup” processes without sleeping?

**Tags:** cognitive-psychology, sleep

> **Comments:**
> **username_0**: yea, but what exacly in sleep / medidation / yoga, make that happen ? imagine you could identify it and reproduce it by just thinking (something like inner procedure activation - dunno if that concept even exists or how its called)  

---

## 2 answers

### Answer by username_1 on 2014-04-18. Score: 2 | Accepted answer

The so-called glymphatic system, pump washing the brain with cerebrospinal fluid during sleep, has already been mentioned in answer to the SE question "Do you need to sleep every night?" It seems more than just a memory cleanup process as if on a computer, but "has significant implications for treating 'dirty brain diseases like Alzheimer's" and understanding it "is a critical first step in efforts to modulate this system and make it work more efficiently" (Maiken Nedergaard). That should go towards answering Q2, at least if such interventions take place in the waking state at the experimental stage.

Another recent report concerns brain cells known as microglia, which also play a role in mopping up neurotoxic brain waste such as beta-amyloids. In addition they monitor the growth of synapses and prune connections between neurons so that the brain can refine its circuits and conserve resources, particularly during adolescence. Relevant maybe, as this is a period in life known for prolonged sleep. Some research on mice suggests a preference on the part of microglia for carrying out their work when the organism is in darkness. Hyperactive microglia however are conjectured to be implicated in Alzheimer's by stripping too many synapses when these are inadvertently tagged by the brain for destruction.

References:

"To Sleep, Perchance to Clean. Study\* reveals brain takes out the trash while we sleep" University of Rochester News Room 17 Oct 2013

\*Nedergaard M (corresponding author) et al "Sleep drives metabolite clearance from the adult brain" Science 18 Oct 2013

"The Mind Minders - a fertile, flexible brain couldn't live without its roving band of caretakers". New Scientist, 12 Oct 2013.


---

### Answer by username_2 on 2014-04-22. Score: 1

There has been studies that shown that cerebrospinal fluid's circulation in the brain is dramatically(20x) increased during sleep. It is believed that **during sleep, cerebrospinal fluid circulation helps clear out toxic by products of brain metabolism.**

> As a result, the cerebrospinal fluid could not only flow more freely
> but it could also reach further into the brain. In an awake brain, it
> would flow only along the brain’s surface. Indeed, the awake flow was
> a mere 5 percent of the sleep flow. In a sleeping brain, waste was
> being cleared two times faster. “We saw almost no inflow of
> cerebrospinal fluid into the brain when the mice were awake, but
> **then when we anesthetized them,** it started flowing. It’s such a big difference

<http://www.nytimes.com/2014/01/12/opinion/sunday/goodnight-sleep-clean.html?_r=0>

<http://www.nih.gov/researchmatters/october2013/10282013clear.htm>

Just a guess - if anesthesia improves cerebrospinal fluid flow, maybe then a combination of [isolation/sensory deprivation tank](http://en.wikipedia.org/wiki/Isolation_tank)and anesthesia would help achieve a cleansing effect? Either way, it does not appear that a human can be running around and working during such cleanup.


---

