How do drugs affect the brain? - Sara Garofalo

Kako lijekovi utječu na mozak? - Sara Garofalo

Prevoditelj: Irma Komljenović Recezent: Dunja Knežević

Većina će ljudi popiti tabletu,

Most people will take a pill,

receive an injection,

dobiti injekciju,

or otherwise take some kind of medicine during their lives,

ili uzeti neku vrstu lijeka tijekom svog života,

but most of us don't know anything about how these substances actually work.

no mnogi ljudi ne znaju kako te tvari djeluju.

How can various compounds impact the way we physically feel,

Kako razni spojevi mogu utjecati na naše osjećaje,

think,

misli,

and even behave?

čak i ponašanje?

For the most part, this depends on how a drug alters the communication

To većinom ovisi o načinu na koji lijek mijenja komunikaciju

between cells in the brain.

stanica u mozgu.

There are a number of different ways that can happen.

Postoji više načina na koje se to može dogoditi.

But before it gets into the brain,

Prije no što dođe u mozak,

any drug must first reach the bloodstream

bilo koji lijek prvo mora doprijeti do krvotoka

on a journey that can take anywhere from seconds to hours,

putovanjem koje može trajati sekundama i satima,

depending on factors like how it's administered.

ovisno o faktorima poput unošenja.

The slowest method is to take a drug orally

Najsporija metoda je oralno uzimanje lijeka

because it must be absorbed by our digestive system

jer ga mora upiti naš probavni sustav

before it takes effect.

prije no što počne djelovati.

Inhaling a drug gets it into the bloodstream faster.

Inhaliranje lijeka dovede ga brže do krvotoka.

And injecting a drug intravenously works quickly too

No ubrizgavanje lijeka intravenozno radi najbrže

because it pumps the chemicals directly into the blood.

jer odmah unosi kemikalije u krv.

Kad se nađe tamo, lijek brzo pronađe svoju ciljanu destinaciju, mozak.

Once there, the drug quickly reaches the gates of its destination, the brain.

The entrance to this organ is guarded by the blood-brain barrier,

Ulaz u taj organ brani krvno-moždana barijera,

which separates blood from the nervous system

koja krv odvaja od živčanog sustava

to keep potentially dangerous substances out.

kako bi potencijalno opasne supstance ostale vani.

So all drugs must have a specific chemical composition

Zato svi lijekovi moraju imati specifični kemijski sastav

which gives them the key to unlock this barrier and pass through.

koji djeluje kao ključ za otključavanje te barijere i dopušta im prolaz.

Once inside, drugs start to interfere with the brain's normal functioning

Kad se nađu unutra, lijekovi se počinju miješati s normalnim radom mozga

by targeting its web of neurons and synapses.

ciljanjem na njegovu mrežu neurona i sinapsi.

Neurons are brain cells that have a nucleus, dendrites, and an axon.

Neuroni su moždane stanice s jezgrom, dendritima i aksonom.

Synapses are structures placed along the dendrites or the axon

Sinapse su strukture smještene uz dendrite ili akson,

which allow the exchange of electrochemical signals between neurons.

zbog čega dolazi do razmjene elektrokemijskih signala među neuronima.

Those signals take the form of chemicals called neurotransmitters.

Ti signali poprimaju oblik kemikalija, neurotransmitera.

Each neurotransmitter plays different roles in regulating our behaviors,

Svaki neurotransmiter ima različitu ulogu u reguliranju naših ponašanja,

emotions,

osjećaja,

and cognition.

i spoznaja.

But they all work in one of two ways.

No svi rade na jedan od dva načina.

They can either inhibit the receiving neuron,

Mogu inhibirati primajući neuron,

limiting its activity,

limitirajući njegovu aktivnost,

or excite it,

ili ga uzbuditi,

creating a new electrochemical signal that spreads throughout the network.

stvarajući pritom novi elektrokemijski signal koji se širi cijelom mrežom.

Any leftover neurotransmitter usually gets degraded

Svaki preostali neurotransmiter razgrađen je

or reabsorbed into the transmitting neuron.

ili resorbiran u prenoseći neuron.

A drug's effectiveness stems from its ability

Uspjeh lijeka određen je njegovom mogućnošću

to manipulate these synaptic transmissions at different phases of the process.

da manipulira sinaptičkim transmisijama u različitim fazama tog procesa.

That results in an increase or a decrease

To rezultira povećanjem ili smanjenjem

in the amount of neurotransmitters being spread.

količine širećih neurotransmitera.

For instance, common antidepressants, like SSRIs,

Na primjer, česti antidepresivi, poput SSRI-ova,

stop the reabsorption of serotonin,

zaustavljaju resorbiranje serotonina,

a neurotransmitter that modulates our moods.

neurotransmitera koji regulira naša raspoloženja.

This effectively pushes more of it into the neural network.

To ih učinkovito izbacuje više u neuronsku mrežu.

Meanwhile, painkillers, like morphine,

Međutim, analgetici, poput morfija,

raise levels of serotonin and noradrenaline,

podižu razine serotonina i noradrenalina,

which regulate energy,

koji reguliraju energiju,

arousal,

uzbuđenje,

alertness,

opreznost,

and pleasure.

i užitak.

Those same neurotransmitters also affect endorphin receptors,

Isti ti neurotransmiteri utječu na receptore za endorfin,

reducing pain perception.

smanjujući percepciju boli.

And tranquilizers works by increasing the production of GABA

Sedativi djeluju jer smanjuju proizvodnju GABA-e

to inhibit neural activity

kako bi inhibirali aktivnost živaca,

putting the person in a relaxed or sedated state.

dovevši pritom osobu u opušteno ili smireno stanje.

What about illegal or elicit drugs?

Što je s ilegalnim ili omamljujućim drogama?

These have powerful impacts on the brain that we're still trying to understand.

Još pokušavamo shvatiti njihov snažni utjecaj na mozak.

Crystal meth, an amphetamine,

Kristalni met, amfetamin,

induces a long-lasting release of dopamine,

izaziva dugotrajno oslobađanje dopamina,

a neurotransmitter linked with the perception of reward and pleasure.

neurotransmitera povezanog s percepcijom nagrađivanja i užitka.

It also activates noradrenaline receptors,

Usto aktivira receptore za noradrenalin,

which increases the heart rate,

koji ubrzava brzinu otkucaja srca,

dilates pupils,

povećava zjenice,

and triggers the body's fight or flight response.

i uključuje reflekse za bijeg ili borbu.

Cocaine blocks the reuptake of dopamine and serotonin,

Kokain zaustavlja reapsorpciju dopamina i serotonina,

pushing more into the network

dovodeći ih još u mrežu

where they boost energy,

gdje podižu energiju,

create feelings of euphoria,

stvaraju osjećaje euforije,

and suppress appetites.

i smanjuju apetit.

And hallucinogenic drugs have some of the most puzzling effects.

Halucinogene droge imaju najčudnije posljedice.

Substances like LSD,

Tvari poput LSD-a,

mescaline,

meskalina,

and DMT

i DMT-a

all block the release of serotonin,

zaustavljaju oslobađanje serotonina,

which regulates mood and impulsivity.

koji regulira raspoloženja i impulzivnost.

They also have an impact on the neural circuits

Utječu i na neuronske krugove

involved in perception, learning, and behavioral regulation,

koji su uključeni u regulaciju percepcije, učenja i ponašanja,

which may explain why these drugs have such powerful impacts.

što objašnjava snažne posljedice ovih droga.

Even if some of these effects sound exciting,

Čak i ako neke od ovih posljedica zvuče uzbudljivo,

there are reasons why some of these drugs are highly controlled and often illegal.

postoje razlozi za strogu kontrolu i, često, nezakonitost tih droga.

Drugs have the power to alter the brain's chemistry,

Droge mogu mijenjati kemiju mozga,

and repeated use can permanently rewire the neural networks

i učestalo korištenje može trajno izmijeniti neuronske mreže

that support our ability to think,

koje podupiru naše sposobnosti razmišljanja,

make decisions,

odlučivanja,

learn,

učenja,

and remember things.

i pamćenja.

There's a lot we still don't know about drugs and their effects,

Još puno toga ne znamo o drogama i njihovim učincima,

both the good and the bad.

ni dobrima ni lošima.

But those we do know about are the ones we've studied closely,

No znamo o onima koje smo pažljivo proučili

and turned into effective medicines.

i pretvorili u učinkovite lijekove.

As our knowledge grows about drugs and the brain,

Sve dok naše znanje o lijekovima i mozgu raste,

the possibilities will also increase

rast će i mogućnosti

for treating the many medical problems that puzzle researchers today.

liječenja mnogih teškoća koje još zbunjuju istraživače.