One more reason to get a good night’s sleep | Jeff Iliff

Translator: Adisa Ejubovic Reviewer: Nedžad Neziri

Sleep.

Spavanje.

It's something we spend about a third of our lives doing,

U tome provodimo trećinu svog života,

but do any of us really understand what it's all about?

ali da li iko od nas zna o čemu se tu zapravo radi?

Two thousand years ago, Galen,

Prije 2000 godina, Galen,

one of the most prominent medical researchers

jedan od najistaknutijih istraživača medicine

of the ancient world,

antičkog doba

proposed that while we're awake,

predložio je da motivaciona snaga našeg mozga,

our brain's motive force, its juice,

njegovi sokovi, u budnom stanju

would flow out to all the other parts of the body,

protiču kroz sve druge dijelove tijela

animating them but leaving the brain all dried up,

i animiraju ih, ali time iscrpljuju mozak.

and he thought that when we sleep,

Galen je pomislio da dok spavamo

all this moisture that filled the rest of the body

sva ta vlažnost koja je ispunila ostatak tijela

would come rushing back,

naglo bi se vratila

rehydrating the brain

i hidrirala mozak

and refreshing the mind.

i osvježila um.

Now, that sounds completely ridiculous to us now,

Nama to sada zvuči baš smiješno,

but Galen was simply trying to explain

ali Galen je prosto pokušao da objasni

something about sleep

nešto vezano za san

that we all deal with every day.

sa čime se susrećemo svaki dan.

See, we all know based on our own experience

Na osnovu svog iskustva, svi znamo

that when you sleep, it clears your mind,

da nam san razbistruje um

and when you don't sleep,

i nedostatak istog

it leaves your mind murky.

čini naš um mutnim.

But while we know a great deal more about sleep now

Iako se danas zna mnogo više o snu

than when Galen was around,

nego kad je Galen bio živ,

we still haven't understood why it is that sleep,

još uvijek ne znamo zašto san

of all of our activities, has this incredible

pored svih drugih aktivnosti, ima nevjerovatnu

restorative function for the mind.

iscjeliteljsku moć nad našim umom.

So today I want to tell you about

Danas želim da vam pričam

some recent research

o nedavnom istraživanju

that may shed new light on this question.

koje možda rasvijetli ovo pitanje.

We've found that sleep may actually be

Otkrili smo da je san zapravo

a kind of elegant design solution

takoreći elegantno rješenje

to some of the brain's most basic needs,

za neke od najosnovnijih potreba mozga,

a unique way that the brain

jedinstven način na koji mozak

meets the high demands and the narrow margins

odgovara na velike zahtijeve i finese

that set it apart from all the other organs of the body.

koje ga razdvajaju od ostalih organa tijela.

So almost all the biology that we observe

Skoro sva biologija koju posmatramo

can be thought of as a series of problems

može se okarakterisati kao niz problema

and their corresponding solutions,

i odgovarajućih rješenja.

and the first problem that every organ must solve

Prvi problem koji svaki organ mora da riješi

is a continuous supply of nutrients to fuel

je konstantna opskrba svih tih ćelija

all those cells of the body.

hranjivim materijama.

In the brain, that is especially critical;

To je posebno bitno za mozak.

its intense electrical activity uses up

Njegova intenzivna električna aktivnost crpi

a quarter of the body's entire energy supply,

četvrtinu ukupne energije tijela

even though the brain accounts

iako mozak zauzima

for only about two percent of the body's mass.

samo oko 2 procenta tjelesne mase.

So the circulatory system

Krvotok rješava

solves the nutrient delivery problem

problem dostave hranjivih materija

by sending blood vessels to supply nutrients

šaljući krvne sudove da obskrbe tim materijama

and oxygen to every corner of our body.

i kiseonikom svaki pedalj našeg tijela.

You can actually see it in this video here.

To možete vidjeti na ovom snimku.

Here, we're imaging blood vessels

Ovdje su prikazani krvni sudovi

in the brain of a living mouse.

u mozgu živog miša.

The blood vessels form a complex network

Krvni sudovi formiraju složenu mrežu

that fills the entire brain volume.

koja ispunjava čitavu zapreminu mozga.

They start at the surface of the brain,

Oni počinju na površini mozga

and then they dive down into the tissue itself,

a onda zadiru u samo tkivo.

and as they spread out, they supply nutrients

Dok se šire, opskrbljuju svaku moždanu ćeliju

and oxygen to each and every cell in the brain.

hranjivim materijama i kiseonikom .

Now, just as every cell requires

Kao što svakoj ćeliji trebaju

nutrients to fuel it,

ove materije za pogon,

every cell also produces waste as a byproduct,

svaka ćelija proizvodi otpad

and the clearance of that waste

i uklanjanje tog otpada

is the second basic problem

je drugi osnovni problem koji

that each organ has to solve.

svaki organ treba da riješi.

This diagram shows the body's lymphatic system,

Ovaj dijagram prikazuje tjelesni limfni sistem

which has evolved to meet this need.

koji je evoluirao kako bi riješio ovaj problem.

It's a second parallel network of vessels

Ovo je drugi paralelni sistem sudova

that extends throughout the body.

koji se prostire po cijelom tijelu.

It takes up proteins and other waste

On sakuplja proteine i drugi otpad

from the spaces between the cells,

iz međućelijskih dijelova

it collects them, and then dumps them into the blood

i onda ih premiješta u krv

so they can be disposed of.

kako bi se oni otklonili.

But if you look really closely at this diagram,

Ako pažljivije pogledate ovaj dijagram

you'll see something

primijetićete da nešto

that doesn't make a lot of sense.

ne štima.

So if we were to zoom into this guy's head,

Ako biste zumirali glavu ovog čovjeka

one of the things that you would see there

ono što vidite je da

is that there are no lymphatic vessels in the brain.

u mozgu nema limfnih sudova.

But that doesn't make a lot of sense, does it?

Ali to nema mnogo smisla.

I mean, the brain is this intensely active organ

Mozak je jedan izuzetno intenzivan organ

that produces a correspondingly large amount of waste

koji shodno tome proizvodi velike količine otpada

that must be efficiently cleared.

koji se mora učinkovito otkloniti.

And yet, it lacks lymphatic vessels, which means that

Ipak, on nema limfne sudove, što znači da

the approach that the rest of the body takes

pristup koji ostatak tijela koristi

to clearing away its waste

kako bi otklonio otpad

won't work in the brain.

neće djelovati u mozgu.

So how, then, does the brain solve

Kako onda mozak rješava

its waste clearance problem?

problem odstranjivanja otpada?

Well, that seemingly mundane question

Kod ovog naizgled svakodnevnog pitanja

is where our group first jumped into this story,

naša prva grupa ulazi u igru.

and what we found

Ono što smo otkrili

as we dove down into the brain,

zaronivši dublje u mozak

down among the neurons and the blood vessels,

dole među neurone i krvne sudove

was that the brain's solution

bilo je da je rješenje mozga

to the problem of waste clearance,

za odstranjivanje otpada

it was really unexpected.

sasvim nesvakidašnje.

It was ingenious,

Bilo je genijalno,

but it was also beautiful.

ali i prelijepo.

Let me tell you about what we found.

Da vam ispričam šta smo našli.

So the brain has this large pool

Mozak ima prostor prepun

of clean, clear fluid called cerebrospinal fluid.

čiste i bistre tečnosti koja se zove cerebrospinalna tečnost.

We call it the CSF.

Mi je zovemo CST.

The CSF fills the space that surrounds the brain,

CST ispunjava prostor koji okružuje mozak

and wastes from inside the brain

i otpad iz mozga

make their way out to the CSF,

ulazi u CST

which gets dumped, along with the waste, into the blood.

koja se zajedno s otpadnom uliva u krv.

So in that way, it sounds a lot like

Ovo puno zvuči kao

the lymphatic system, doesn't it?

limfni sistem, zar ne?

But what's interesting is that the fluid and the waste

Ono što je interesantno je da tečnost i otpad

from inside the brain,

iz mozga

they don't just percolate their way randomly

ne izlaze nasumično

out to these pools of CSF.

iz ovog prostora CST-a.

Instead, there is a specialized network of plumbing

Naprotiv, postoji specijalizovan sistem

that organizes and facilitates this process.

koji organizuje i podupire ovaj proces.

You can see that in these videos.

To možete vidjeti na ovim snimcima.

Here, we're again imaging into the brain

Ovdje ponovo imate prikaz mozga

of living mice.

živog miša.

The frame on your left shows

Slika lijevo prikazuje

what's happening at the brain's surface,

šta se dešava na površini mozga

and the frame on your right shows

a slika desno prikazuje

what's happening down below the surface of the brain

šta se dešava ispod površine mozga

within the tissue itself.

unutar samog tkiva.

We've labeled the blood vessels in red,

Krvni sudovi su crvene boje

and the CSF that's surrounding the brain

a CST koja okružuje mozak

will be in green.

je zelene.

Now, what was surprising to us

Ono što nas je iznenadilo je

was that the fluid on the outside of the brain,

to da tečnost izvan mozga

it didn't stay on the outside.

nije ostala izvan njega.

Instead, the CSF was pumped back into

CST se vratila unutar

and through the brain

i prošla kroz krv

along the outsides of the blood vessels,

duž vanjskog dijela krvnih sudova.

and as it flushed down into the brain

Dok se spuštala u mozak

along the outsides of these vessels,

duž vanjskog dijela ovih sudova

it was actually helping to clear away,

ona je zapravo pomagala u otklanjanju

to clean the waste from the spaces

otpada iz

between the brain's cells.

međućelijskog prostora.

If you think about it,

Ako razmislite o tome,

using the outsides of these blood vessels like this

korištenje vanjskog dijela ovih sudova

is a really clever design solution,

je jako pametno rješenje

because the brain is enclosed

jer je mozak zatvoren

in a rigid skull

u čvrstu lobanju

and it's packed full of cells,

i prepun je ćelija

so there is no extra space inside it

tako da u njemu nema dodatnog prostora

for a whole second set of vessels like the lymphatic system.

za čitav set sudova jednog limfnog sistema.

Yet the blood vessels,

Ipak, krvni sudovi

they extend from the surface of the brain

se protežu sa površine mozga

down to reach every single cell in the brain,

do svake žive ćelije mozga

which means that fluid

što znači da tečnost

that's traveling along the outsides of these vessels

koja putuje duž vanjskog dijela krvnih sudova

can gain easy access to the entire brain's volume,

može dobiti pristup cijelokupnoj zapremini mozga,

so it's actually this really clever way

tako da je ovo jako pametan način

to repurpose one set of vessels, the blood vessels,

za prekvalifikaciju jednog seta sudova,

to take over and replace the function

krvnih sudova, koji preuzimaju funkciju

of a second set of vessels, the lymphatic vessels,

drugog seta sudova, limfnih sudova

to make it so you don't need them.

kako bi se pobrinuli da ih ne trebamo.

And what's amazing is that no other organ

Ono što je zapanjujuće je da nijedan drugi organ

takes quite this approach

ne koristi ovaj pristup

to clearing away the waste from between its cells.

kako bi otklonio međućelijski otpad.

This is a solution that is entirely unique to the brain.

Ovo rješenje je karakteristično samo za mozak.

But our most surprising finding

Ali najiznenađujuće otkriće

was that all of this,

je da se sve ovo

everything I just told you about,

što sam vam rekao

with all this fluid rushing through the brain,

o ovoj tečnosti koja ide kroz mozak

it's only happening in the sleeping brain.

samo se dešava u stanju sna.

Here, the video on the left

Snimak lijevo

shows how much of the CSF is moving

pokazuje koliko se CST kreće

through the brain of a living mouse while it's awake.

kroz mozak miša koji je budan.

It's almost nothing.

Skoro pa ništa.

Yet in the same animal,

Ali u istoj životinji

if we wait just a little while until it's gone to sleep,

ako samo malo sačekamo da zaspi

what we see is that the CSF

ono što vidimo je da CST

is rushing through the brain,

poput bujice ide kroz mozak.

and we discovered that at the same time

Otkrili smo i da u isto vrijeme

when the brain goes to sleep,

kada mozak zaspi

the brain cells themselves seem to shrink,

moždane ćelije se, čini se, smanje

opening up spaces in between them,

i daju malo međuprostora,

allowing fluid to rush through

što omogućava tečnosti da jurne

and allowing waste to be cleared out.

i time očisti otpad.

So it seems that Galen may actually have been

Izgleda da je Galen zapravo

sort of on the right track when he wrote about

bio na pravom putu kada je pisao o

fluid rushing through the brain

tečnosti koja šiklja kroz mozak

when sleep came on.

kada spavamo.

Our own research, now it's 2,000 years later,

Naše istraživanje, 2000 godina poslije,

suggests that what's happening is that

upućuje na to da

when the brain is awake

kada je mozak budan

and is at its most busy,

i najzauzetiji

it puts off clearing away the waste

on odgađa odstranjivanje otpada

from the spaces between its cells until later,

iz međućelijskog prostora

and then, when it goes to sleep

i onda kada zaspi

and doesn't have to be as busy,

i nije toliko zauzet

it shifts into a kind of cleaning mode

prebacuje se u stanje čišćenja

to clear away the waste

i odstranjuje otpad

from the spaces between its cells,

iz međućelijskog prostora,

the waste that's accumulated throughout the day.

otpad koji se nakuplja tokom dana.

So it's actually a little bit like how you or I,

To je nekako kao kad vi ili ja

we put off our household chores during the work week

odgađamo naše kućanske poslove u toku radne sedmice

when we don't have time to get to it,

kada nemamo puno vremena

and then we play catch up on all the cleaning that we have to do

i onda kada dođe vikend

when the weekend rolls around.

trudimo se da sve nadoknadimo.

Now, I've just talked a lot about waste clearance,

Puno sam pričao o odstranjivanju otpada

but I haven't been very specific

ali nisam bio konkretan

about the kinds of waste

u vezi sa tipovima otpada

that the brain needs to be clearing

koje mozak treba da odstrani

during sleep in order to stay healthy.

tokom sna kako bi ostao zdrav.

The waste product that these recent studies

Štetni proizvod na koji se

focused most on is amyloid-beta,

recentne studije mahom fokusiraju je amiloid-beta.

which is a protein that's made in the brain all the time.

To je protein koji se konstantno proizvodi u mozgu.

My brain's making amyloid-beta right now,

Moj mozak upravo proizvodi amiloid-betu

and so is yours.

a i vaš.

But in patients with Alzheimer's disease,

Ali kog oboljelih od Alchajmerove

amyloid-beta builds up and aggregates

amiloid-beta se nakuplja

in the spaces between the brain's cells,

u međućelijskom prostoru

instead of being cleared away like it's supposed to be,

umjesto da se otklanja

and it's this buildup of amyloid-beta

i smatra se da su upravo ove nakupine

that's thought to be one of the key steps

amiloid-bete jedan od ključnih koraka

in the development of that terrible disease.

u razvitku ove strašne bolesti.

So we measured how fast amyloid-beta is cleared

Izmjerili smo koliko brzo se amiloid-beta otklanja

from the brain when it's awake

iz mozga u budnom stanju

versus when it's asleep,

a koliko u snu.

and we found that indeed,

Otkrili smo da, zaista,

the clearance of amyloid-beta

otklanjanje amiloid-bete

is much more rapid from the sleeping brain.

je mnogo brže u mozgu koji spava.

So if sleep, then,

Ako je spavanje

is part of the brain's solution

dio rješenja mozga

to the problem of waste clearance,

za problem otklanjanja otpada

then this may dramatically change how we think

onda će ovo itekako promijeniti naše razmišljanje

about the relationship between sleep,

o vezi između sna,

amyloid-beta, and Alzheimer's disease.

amiloid-bete i Alchajmerove bolesti.

A series of recent clinical studies

Niz skorašnjih kliničkih studija

suggest that among patients

upućuje da među pacijentima

who haven't yet developed Alzheimer's disease,

koji još uvijek nisu dobili Alchajmerovu

worsening sleep quality and sleep duration

pogoršano spavanje i njegovo trajanje

are associated with a greater amount

su povezani sa većom količinom

of amyloid-beta building up in the brain,

nakupina amiloid-bete u mozgu.

and while it's important to point out

Važno je istaknuti da, iako

that these studies don't prove

ove studije ne dokazuju

that lack of sleep or poor sleep

da nedostatak ili loš san

cause Alzheimer's disease,

uzrokuju Alchajmerovu,

they do suggest that the failure of the brain

one upućuju da neuspjeh mozga

to keep its house clean

da očisti kuću

by clearing away waste like amyloid-beta

uklanjajući otpad poput amiloid-bete

may contribute to the development

može doprinijeti razvitku

of conditions like Alzheimer's.

bolesti poput Alchajmerove.

So what this new research tells us, then,

Ono što nam ovo istraživanje govori

is that the one thing that all of you

je da jedna stvar koju ste svi

already knew about sleep,

već znali o snu,

that even Galen understood about sleep,

koju je čak i Galen shvatio,

that it refreshes and clears the mind,

da osvježava i razbistruje um,

may actually be a big part

je možda glavni razlog

of what sleep is all about.

što san postoji.

See, you and I, we go to sleep

Vi i ja, mi idemo na spavanje

every single night,

svako veče,

but our brains, they never rest.

ali naš mozak se nikada ne odmara.

While our body is still

Dok naše tijelo miruje

and our mind is off walking in dreams somewhere,

i naš um hoda u snovima,

the elegant machinery of the brain

elegantna mašinerija našeg mozga

is quietly hard at work

marljivo radi svoj posao,

cleaning and maintaining

čisti i održava

this unimaginably complex machine.

ovu nevjerovatno složenu mašinu.

Like our housework,

Kao i kućanski posao,

it's a dirty and a thankless job,

to je prljav i nezahvalan posao,

but it's also important.

ali je isto jako bitan.

In your house, if you stop cleaning your kitchen

Ako prestanete da čistite kuhinju

for a month,

na jedan mjesec

your home will become completely unlivable

vaša kuća vrlo brzo neće imati

very quickly.

uslove za život.

But in the brain, the consequences

Ali u mozgu, posljedice neuspjeha

of falling behind may be much greater

mogu biti mnogo ozbiljnije

than the embarrassment of dirty countertops,

od nelagode uzrokovane prašnjavim kredencima,

because when it comes to cleaning the brain,

jer kada je u pitanju mozak

it is the very health and function

zdravlje i funkcija

of the mind and the body that's at stake,

uma i tijela je na kocki

which is why understanding these

i zbog toga, shvatanje ovih

very basic housekeeping functions of the brain today

osnovnih funkcija čišćenja našeg mozga danas

may be critical for preventing and treating

možda je od presudne važnosti za prevenciju i liječenje

diseases of the mind tomorrow.

bolesti uma sutra.

Thank you.

Hvala.

(Applause)