What are mini brains? - Madeline Lancaster

Prevodilac: Dragana Radmanovic Lektor: Ivana Korom

This pencil-eraser-sized mass of cells is something called a brain organoid.

Ova masa ćelija veličine gumice na olovci je nešto što se zove moždani organoid.

It’s a collection of lab-grown neurons and other brain tissue

To je skup neurona i drugih moždanih tkiva razvijenih u laboratoriji,

that scientists can use to learn about full-grown human brains.

koje naučnici mogu da koriste u cilju učenja o razvijenom ljudskom mozgu.

And it can be grown from a sample of your skin cells.

I mogu se razviti iz uzorka ćelija kože.

Why would we need such a thing?

Zašto nam to treba?

Neuroscientists face a challenge:

Neuronaučnici se nalaze pred izazovom:

shielded by our thick skulls and swaddled in layers of protective tissue,

zaštićen čvrstom lobanjom i obmotan slojevima zaštitnog tkiva,

the human brain is extremely difficult to observe in action.

ljudski mozak je veoma teško posmatrati u akciji.

For centuries, scientists have tried to understand them using autopsies,

Vekovima su naučnici pokušavali da ih razumeju koristeći se autopsijama,

animal models,

modelima životinja,

and, in recent years, imaging techniques.

i poslednjih godina, tehnikama vizualizacije.

We’ve learned a lot through all these methods,

Naučili smo dosta kroz ove metode,

but they have limitations.

ali njihov domet je ograničen.

Conditions like Alzheimer’s and schizophrenia,

Stanja poput Alzhajmerove bolesti ili šizofrenije,

and the effect on the human brain of diseases like Zika,

i posledice po ljudski mozak bolesti kao što je Zika,

continue to hide beyond our view, and our understanding.

su nam i dalje nedostupni za posmatranje i razumevanje.

Enter brain organoids, which function like human brains

Tu nastupaju moždani organoidi, koji funkcionišu baš kao i ljudski mozak

but aren’t part of an organism.

ali nisu deo organizma.

Each one comes from an undifferentiated stem cell,

Svaki nastaje iz neizdiferencirane matične ćelije,

which is a cell that can develop into any tissue in the body,

koja je ćelija koja se može razviti u bilo koje tkivo u telu,

from bone to brain.

od kosti do mozga.

Scientists can make undifferentiated stem cells from skin cells.

Naučnici mogu da stvore neizdiferencirane matične ćelije od ćelija kože.

That means they can take a skin sample from a person with a particular condition

To znači da mogu da uzmu uzorak kože od osobe sa određenim stanjem

and generate brain organoids from that person.

i da od te osobe generišu moždane organoide.

The hardest part of growing a brain organoid,

Najteži deo kod razvoja moždanih organoida,

which stumped scientists for years,

koji je sputavao naučnike godinama,

was finding the perfect combination of sugars, proteins, vitamins, and minerals

je bilo pronalaženje savršene kombinacije šećera, proteina, vitamina i minerala

that would induce the stem cell to develop a neural identity.

koja bi navela matičnu ćeliju da razvije neuronski identitet.

That was only discovered recently, in 2013.

To je bilo otkriveno tek skoro, 2013. godine.

The rest of the process is surprisingly easy.

Ostatak procesa je iznenađujuće lak.

A neural stem cell essentially grows itself,

Neuronska matična ćelija se u suštini razvija,

similar to how a seed grows into a plant,

na sličan način na koji se seme razvija u biljku,

all it needs are the brain’s equivalents of soil, water, and sunlight.

sve što joj je potrebno su moždani ekvivalenti zemlji, vodi i suncu.

A special gel to simulate embryonic tissue,

Specijalni gel da simulira embrioničko tkivo,

a warm incubator set at body temperature,

topao inkubator podešen na temperaturu tela,

and a bit of motion to mimic blood flow.

i malo kretanja da podražava kretanje krvi.

The stem cell grows into a very small version

Matična ćelija se razvija u veoma malu verziju

of an early-developing human brain,

mozga u ranoj fazi razvoja,

complete with neurons that can connect to one another

zajedno sa neuronima koji mogu da se međusobno povezuju

and make simplified neural networks.

i da stvaraju pojednostavljene neuronske mreže.

As mini brains grow, they follow all the steps of fetal brain development.

Kako mini mozgovi rastu, oni prate sve korake razvoja mozga fetusa.

By observing this process, we can learn how our neurons develop,

Posmatrajući ovaj proces, možemo da vidimo kako se naši neuroni razvijaju,

as well as how we end up with so many more of them in our cortex,

kao i kako završavamo sa mnogo više njih u našem korteksu,

the part responsible for higher cognition like logic and reasoning,

delu odgovornom za višu kogniciju, kao što su logika i rasuđivanje,

than other species.

nego druge vrste.

Being able to grow brains in the lab, even tiny ones,

Sposobnost razvoja mozgova u laboratoriji, čak i malih,

raises ethical questions, like:

nameće etička pitanja, kao što su:

Can they think for themselves, or develop consciousness?

mogu li oni da misle za sebe i mogu li da razviju svest?

And the answer is no, for several reasons.

I odgovor je ne, zbog nekoliko razloga.

A brain organoid has the same tissue types as a full-sized brain,

Moždani organoid ima isti tip tkiva kao i potpuno razvijen mozak,

but isn’t organized the same way.

ali nije organizovan na isti način.

The organoid is similar to an airplane

Organoid je sličan avionu

that’s been taken apart and reassembled at random;

koji je rastavljen i nasumično sastavljen;

you could still study the wings, the engine, and other parts,

I dalje je moguće proučavati krila, motor i druge delove,

but the plane could never fly.

ali avion ne može nikako da leti.

Similarly, a brain organoid allows us to study different types of brain tissue,

Na sličan način,

moždani organoid nam dozvoljava da izučavamo različite tipove moždanog tkiva,

but can’t think.

ali on ne može da misli.

And even if mini brains were organized like a real brain,

Čak i da su mini mozgovi organizovani kao pravi mozak,

they still wouldn’t be able to reason or develop consciousness.

i dalje ne bi bili u stanju da rasuđuju ili da razviju svest.

A big part of what makes our brains so smart is their size,

Velikim delom to što čini naše mozgove tako pametnim je njihova veličina

and mini brains have only about 100,000 neurons

i mini mozgovi imaju samo oko 100 000 neurona

compared to the 86 billion in a full-sized brain.

u odnosu na 86 milijardi u potpuno razvijenom mozgu.

Scientists aren’t likely to grow larger brain organoids anytime soon.

Naučnici najverovatnije neće razvijati veće moždane organoide uskoro.

Without blood vessels to feed them,

Bez krvnih sudova koji bi ih hranili,

their size is limited to one centimeter at most.

njihova veličina je ograničena na najviše jedan centimetar.

Finally, mini brains aren’t able to interact with the outside world.

Naposletku, mini mozgovi nisu u stanju da iteraguju sa spoljašnjim svetom.

We learn by interacting with our environments: receiving inputs

Učimo u interakciji sa okruženjem: primajući informacije

through our eyes, ears, and other sensory organs, and reacting in turn.

kroz oči, uši, i druge senzorne organe, i reagujući na njih za uzvrat.

The complex neural networks that underlie conscious thoughts and actions

Kompleksna neuralna mreža na kojoj se baziraju svesne misli i akcije

develop from this feedback loop.

se razvija iz ove povratne petlje.

Without it, the organoids can never form a functional network.

Bez nje, organoidi nikada ne mogu da formiraju funkcionalnu mrežu.

There’s nothing quite like the actual human brain,

Nema ničega poput stvarnog ljudskog mozga,

but mini brains are an unprecedented tool

ali su mini mozgovi jedinstveno sredstvo

for studying everything from development to disease.

za izučavanje svega, od razvoja do bolesti.

With luck, these humble organoids can help us discover

Uz malo sreće, ovi skromni organoidi nam mogu pomoći da otkrijemo

what makes the human brain unique,

šta čini ljudski mozak jedinstvenim,

and maybe bring us closer to answering the age-old question:

i možda nas mogu približiti odgovoru na drevno pitanje:

what makes us human?

šta je to što nas čini ljudima?