How do drugs affect the brain? - Sara Garofalo
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0:07 - 0:09Most people will take a pill,
-
0:09 - 0:10receive an injection,
-
0:10 - 0:13or otherwise take some kind of medicine
during their lives, -
0:13 - 0:18but most of us don't know anything
about how these substances actually work. -
0:18 - 0:22How can various compounds impact the way
we physically feel, -
0:22 - 0:23think,
-
0:23 - 0:25and even behave?
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0:25 - 0:29For the most part, this depends on
how a drug alters the communication -
0:29 - 0:31between cells in the brain.
-
0:31 - 0:34There are a number of different ways
that can happen. -
0:34 - 0:36But before it gets into the brain,
-
0:36 - 0:38any drug must first reach the bloodstream
-
0:38 - 0:42on a journey that can take anywhere
from seconds to hours, -
0:42 - 0:44depending on factors like how
it's administered. -
0:44 - 0:47The slowest method is to take
a drug orally -
0:47 - 0:50because it must be absorbed by
our digestive system -
0:50 - 0:52before it takes effect.
-
0:52 - 0:55Inhaling a drug gets it into
the bloodstream faster. -
0:55 - 0:59And injecting a drug intravenously
works quickly too -
0:59 - 1:02because it pumps the chemicals directly
into the blood. -
1:02 - 1:07Once there, the drug quickly reaches
the gates of its destination, the brain. -
1:07 - 1:11The entrance to this organ is guarded
by the blood-brain barrier, -
1:11 - 1:13which separates blood
from the nervous system -
1:13 - 1:16to keep potentially dangerous
substances out. -
1:16 - 1:19So all drugs must have a specific
chemical composition -
1:19 - 1:24which gives them the key to unlock
this barrier and pass through. -
1:24 - 1:27Once inside, drugs start to interfere
with the brain's normal functioning -
1:27 - 1:31by targeting its web of neurons
and synapses. -
1:31 - 1:35Neurons are brain cells that have
a nucleus, dendrites, and an axon. -
1:35 - 1:40Synapses are structures placed along
the dendrites or the axon -
1:40 - 1:44which allow the exchange of
electrochemical signals between neurons. -
1:44 - 1:48Those signals take the form of chemicals
called neurotransmitters. -
1:48 - 1:51Each neurotransmitter plays different
roles in regulating our behaviors, -
1:51 - 1:52emotions,
-
1:52 - 1:53and cognition.
-
1:53 - 1:56But they all work in one of two ways.
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1:56 - 1:58They can either inhibit
the receiving neuron, -
1:58 - 2:00limiting its activity,
-
2:00 - 2:01or excite it,
-
2:01 - 2:05creating a new electrochemical signal
that spreads throughout the network. -
2:05 - 2:08Any leftover neurotransmitter usually
gets degraded -
2:08 - 2:11or reabsorbed
into the transmitting neuron. -
2:11 - 2:14A drug's effectiveness stems
from its ability -
2:14 - 2:19to manipulate these synaptic transmissions
at different phases of the process. -
2:19 - 2:21That results in an increase or a decrease
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2:21 - 2:25in the amount of neurotransmitters
being spread. -
2:25 - 2:28For instance, common antidepressants,
like SSRIs, -
2:28 - 2:31stop the reabsorption of serotonin,
-
2:31 - 2:35a neurotransmitter that modulates
our moods. -
2:35 - 2:38This effectively pushes more of it
into the neural network. -
2:38 - 2:40Meanwhile, painkillers, like morphine,
-
2:40 - 2:43raise levels of serotonin
and noradrenaline, -
2:43 - 2:45which regulate energy,
-
2:45 - 2:46arousal,
-
2:46 - 2:47alertness,
-
2:47 - 2:48and pleasure.
-
2:48 - 2:52Those same neurotransmitters also
affect endorphin receptors, -
2:52 - 2:54reducing pain perception.
-
2:54 - 2:58And tranquilizers works by increasing
the production of GABA -
2:58 - 3:00to inhibit neural activity
-
3:00 - 3:04putting the person in a relaxed
or sedated state. -
3:04 - 3:06What about illegal or elicit drugs?
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3:06 - 3:11These have powerful impacts on the brain
that we're still trying to understand. -
3:11 - 3:13Crystal meth, an amphetamine,
-
3:13 - 3:16induces a long-lasting release
of dopamine, -
3:16 - 3:21a neurotransmitter linked with
the perception of reward and pleasure. -
3:21 - 3:24It also activates noradrenaline receptors,
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3:24 - 3:25which increases the heart rate,
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3:25 - 3:26dilates pupils,
-
3:26 - 3:30and triggers the body's fight
or flight response. -
3:30 - 3:33Cocaine blocks the reuptake of dopamine
and serotonin, -
3:33 - 3:35pushing more into the network
-
3:35 - 3:36where they boost energy,
-
3:36 - 3:38create feelings of euphoria,
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3:38 - 3:40and suppress appetites.
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3:40 - 3:44And hallucinogenic drugs have some
of the most puzzling effects. -
3:44 - 3:46Substances like LSD,
-
3:46 - 3:47mescaline,
-
3:47 - 3:48and DMT
-
3:48 - 3:50all block the release of serotonin,
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3:50 - 3:53which regulates mood and impulsivity.
-
3:53 - 3:55They also have an impact
on the neural circuits -
3:55 - 4:00involved in perception, learning,
and behavioral regulation, -
4:00 - 4:04which may explain why these drugs
have such powerful impacts. -
4:04 - 4:07Even if some of these
effects sound exciting, -
4:07 - 4:11there are reasons why some of these drugs
are highly controlled and often illegal. -
4:11 - 4:13Drugs have the power to alter
the brain's chemistry, -
4:13 - 4:17and repeated use can permanently
rewire the neural networks -
4:17 - 4:19that support our ability to think,
-
4:19 - 4:20make decisions,
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4:20 - 4:21learn,
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4:21 - 4:23and remember things.
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4:23 - 4:26There's a lot we still don't know
about drugs and their effects, -
4:26 - 4:28both the good and the bad.
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4:28 - 4:32But those we do know about are the ones
we've studied closely, -
4:32 - 4:34and turned into effective medicines.
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4:34 - 4:37As our knowledge grows about drugs
and the brain, -
4:37 - 4:39the possibilities will also increase
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4:39 - 4:43for treating the many medical problems
that puzzle researchers today.
- Title:
- How do drugs affect the brain? - Sara Garofalo
- Description:
-
View full lesson: http://ed.ted.com/lessons/how-do-drugs-affect-the-brain-sara-garofalo
Most people will take a pill, receive an injection, or otherwise take some kind of medicine during their lives. But most of us don’t know anything about how these substances actually work. How can various compounds impact the way we physically feel, think, and even behave? Sara Garofalo explains how some drugs can alter the communication between cells in the brain.
Lesson by Sara Garofalo, animation by Adriatic Animation.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 05:05
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Ростислав Голод commented on English subtitles for How do drugs affect the brain? - Sara Garofalo | ||
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Ростислав Голод
You've got a misspell in 3:03. Should be ''illicit'' NOT ''elicit"!