You smell with your body, not just your nose | Jennifer Pluznick

Prevoditelj: Snjezana Volaric Recezent: Sanda L

Here's a question for you:

Pitanje za vas:

how many different scents do you think you can smell,

Koliko različitih mirisa mislite da možete nanjušiti,

and maybe even identify with accuracy?

a možda i prepoznati sa sigurnošću?

100?

100?

300?

300?

1,000?

1000?

One study estimates that humans can detect up to one trillion different odors.

Jedna studija procjenjuje da ljudi mogu prepoznati do trilijun različitih mirisa.

A trillion.

Trilijun.

It's hard to imagine,

Teško je to zamisliti,

but your nose has the molecular machinery to make it happen.

ali vaš nos ima molekularni mehanizam koji je u stanju to omogućiti.

Olfactory receptors --

Olfaktorni receptori,

tiny scent detectors --

sićušni detektori mirisa,

are packed into your nose,

smješteni su u vašem nosu,

each one patiently waiting to be activated by the odor,

svaki strpljivo čeka da ga aktivira miris,

or ligand,

ili ligand,

that it's been assigned to detect.

koji je zadužen da ga detektira.

It turns out we humans, like all vertebrates,

Ispada da mi ljudi, poput svih kralježnjaka,

have lots of olfactory receptors.

imamo mnogo olfaktornih receptora.

In fact, more of our DNA is devoted to genes for different olfactory receptors

Zapravo, više naše DNA posvećeno je genima za različite olfaktorne receptore,

than for any other type of protein.

nego za bilo koji drugi tip proteina.

Why is that?

Zašto je to tako?

Could olfactory receptors be doing something else

Bi li olfaktorni receptori mogli služiti još nečemu,

in addition to allowing us to smell?

osim što nam omogućuju da osjećamo mirise?

In 1991, Linda Buck and Richard Axel uncovered the molecular identity

1991. Linda Buck i Richard Axel otkrili su molekularni identitet

of olfactory receptors --

olfaktornih receptora,

work which ultimately led to a Nobel Prize.

rad koji ih je doveo do Nobelove nagrade.

At the time,

U to vrijeme

we all assumed that these receptors were only found in the nose.

svi smo pretpostavljali da se ovi receptori nalaze samo u nosu.

However, about a year or so later,

Međutim, nešto više od godine kasnije,

a report emerged of an olfactory receptor expressed in a tissue

pojavilo se izvješće o jednom olfaktornom receptoru koji se pojavio u tkivu

other than the nose.

koje nije nos.

And then another such report emerged,

I onda se pojavilo još jedno takvo izvješće

and another.

i još jedno.

We now know that these receptors are found all over the body,

Sada znamo da se takvi receptori mogu pronaći po čitavom tijelu,

including in some pretty unexpected places --

uključujući i neka prilično neočekivana mjesta,

in muscle,

u mišićima,

in kidneys,

u bubrezima,

lungs

plućima

and blood vessels.

i krvnim žilama.

But what are they doing there?

Ali što rade tamo?

Well, we know that olfactory receptors act as sensitive chemical sensors

Pa, znamo da se olfaktorni receptori ponašaju kao osjetljivi kemijski senzori

in the nose --

u nosu,

that's how they mediate our sense of smell.

čime su posrednici našem osjetilu njuha.

It turns out they also act as sensitive chemical sensors

Otkrilo se da se također ponašaju kao osjetljvi kemijski senzori

in many other parts of the body.

u mnogim drugim dijelovima tijela.

Now, I'm not saying that your liver can detect the aroma of your morning coffee

Sad, ne kažem da vaša jetra može osjetiti aromu vaše jutarnje kave

as you walk into the kitchen.

dok hodate prema kuhinji.

Rather, after you drink your morning coffee,

Nego, nakon što popijete svoju jutarnju kavu,

your liver might use an olfactory receptor

vaša jetra može iskoristiti olfaktorni receptor

to chemically detect the change in concentration

kako bi kemijski detektirala promjenu u koncentraciji

of a chemical floating through your bloodstream.

kemijske fluktuacije kroz vaš krvotok.

Many cell types and tissues in the body use chemical sensors,

Mnoge vrste stanica i tkiva u tijelu koriste kemijske senzore,

or chemosensors,

ili kemosenzore,

to keep track of the concentration of hormones, metabolites

kako bi pratili koncentraciju hormona, metabolita

and other molecules,

i ostalih molekula,

and some of these chemosensors are olfactory receptors.

a neki od ovih kemosenzora su olfaktorni receptori.

If you are a pancreas or a kidney

Ako ste gušterača ili bubreg

and you need a specialized chemical sensor

i trebate specijalizirani kemijski senzor,

that will allow you to keep track of a specific molecule,

koji će vam omogućiti praćenje određene molekule,

why reinvent the wheel?

zašto otkrivati toplu vodu?

One of the first examples

Jedan od prvih primjera

of an olfactory receptor found outside the nose

olfaktornog receptora pronađenog izvan nosa,

showed that human sperm express an olfactory receptor,

pokazao je da ljudska sperma ima olfaktorni receptor

and that sperm with this receptor will seek out the chemical

i da će sperma ovim receptorom tražiti kemikaliju

that the receptor responds to --

kojoj taj receptor odgovara --

the receptor's ligand.

receptorov ligand.

That is, the sperm will swim toward the ligand.

Odnosno, sperma će plivati prema ligandu.

This has intriguing implications.

To ima intrigantne implikacije.

Are sperm aided in finding the egg

Pomaže li spermi u pronalasku jajašca

by sniffing out the area with the highest ligand concentration?

njuškanje područja s najvišom koncentracijom liganada?

I like this example because it clearly demonstrates

Volim ovaj primjer jer jasno pokazuje

that an olfactory receptor's primary job is to be a chemical sensor,

da je primarni posao olfaktornog receptora to da bude kemijski senzor,

but depending on the context,

ali ovisno o kontekstu,

it can influence how you perceive a smell,

može utjecati na vašu percepciju mirisa,

or in which direction sperm will swim,

ili u kojem će smjeru plivati sperma

and as it turns out,

te, kao što se pokazuje,

a huge variety of other processes.

utječe na čitav niz drugih procesa.

Olfactory receptors have been implicated in muscle cell migration,

Pretpostavlja se da olfaktorni receptori sudjeluju u migraciji mišićnih stanica,

in helping the lung to sense and respond to inhaled chemicals,

u pomaganju plućima da osjete i odgovore na udahnute kemikalije

and in wound healing.

te započnu iscjeljivanje.

Similarly, taste receptors once thought to be found only in the tongue,

Slično, za okusne receptore se nekada mislilo da se nalaze isključivo na jeziku,

are now known to be expressed in cells and tissues throughout the body.

a sada se zna da se javljaju u stanicama i tkivima u cijelom tijelu.

Even more surprisingly,

Ono što još više iznenađuje,

a recent study found

nedavna je studija pokazala

that the light receptors in our eyes also play a role in our blood vessels.

da receptori za svjetlo u našim očima igraju ulogu i u našim krvnim žilama.

In my lab,

U mojem laboratoriju

we work on trying to understand the roles of olfactory receptors and taste receptors

radimo na pokušaju razumijevanja uloga olfaktornih i okusnih receptora

in the context of the kidney.

u kontekstu bubrega.

The kidney is a central control center for homeostasis.

Bubreg je središnji kontrolni centar za homeostazu.

And to us,

I nama

it makes sense that a homeostatic control center would be a logical place

ima smisla da bi homeostatski kontrolni centar bio logično mjesto

to employ chemical sensors.

za korištenje kemijskih senzora.

We've identified a number of different olfactory and taste receptors

Identificirali smo određen broj različitih olfaktornih i okusnih receptora

in the kidney,

u bubregu,

one of which, olfactory receptor 78,

od kojih se za jedan, olfaktorni receptor 78,

is known to be expressed in cells and tissues

zna da se javlja u stanicama i tkivima

that are important in the regulation of blood pressure.

koji su važni za regulaciju krvnog tlaka.

When this receptor is deleted in mice,

Kada se miševima taj receptor ukloni,

their blood pressure is low.

njihov krvni tlak je nizak.

Surprisingly, this receptor was found to respond

Iznenađujuće, ovaj receptor odgovara

to chemicals called short-chain fatty acids

na kemijske spojeve poznate kao masne kiseline kratkog lanca,

that are produced by the bacteria that reside in your gut --

koje proizvodi bakterija koja živi u vašem crijevu,

your gut microbiota.

vaša crijevna mikrobiota.

After being produced by your gut microbiota,

Nakon što ih vaša crijevna mikrobiota proizvede,

these chemicals are absorbed into your bloodstream

ovi kemijski spojevi se apsorbiraju u vaš krvotok,

where they can then interact with receptors

gdje mogu ući u interakciju s receptorima

like olfactory receptor 78,

poput olfaktornog receptora 78,

meaning that the changes in metabolism of your gut microbiota

što znači da promjene u metabolizmu vaše crijevne makrobiote

may influence your blood pressure.

mogu utjecati na vaš krvni tlak.

Although we've identified a number of different olfactory and taste receptors

Iako smo identificirali određeni broj različitih olfaktornih i okusnih receptora

in the kidney,

u bubregu,

we've only just begun to tease out their different functions

tek smo započeli otkrivati njihove važne funkcije

and to figure out which chemicals each of them responds to.

i shvaćati koje kemikalije odgovaraju svakome od njih.

Similar investigations lie ahead for many other organs and tissues --

Slična istraživanja slijede za mnoge druge organe i tkiva --

only a small minority of receptors has been studied to date.

do danas je istražen tek mali broj receptora.

This is exciting stuff.

Uzbudljivo je to.

It's revolutionizing our understanding of the scope of influence

Drastično se mijenja naše razumijevanje dosega utjecaja

for one of the five senses.

za jedno od pet osjetila.

And it has the potential to change our understanding

I ima potencijal promijeniti naše razumijevanje

of some aspects of human physiology.

nekih aspekata ljudske fiziologije.

It's still early,

Još je rano,

but I think we've picked up on the scent of something we're following.

ali mislim da smo nanjušili nešto što slijedimo.

(Laughter)

(Smijeh)

Thank you.

Hvala vam.

(Applause)

(Pljesak)