David Anderson: Your brain is more than a bag of chemicals

163,785 views ・ 2013-03-12

TED


Dvaput kliknite na engleske titlove ispod za reprodukciju videozapisa.

00:00
Translator: Joseph Geni Reviewer: Morton Bast
0
0
7000
Prevoditelj: Barbara Safaric Recezent: Vedrana Vučković Jakšić
00:15
So raise your hand if you know someone
1
15890
3228
Dignite ruku ako znate nekog
00:19
in your immediate family or circle of friends
2
19118
2647
u svojoj užoj obitelji ili krugu bliskih prijatelja
00:21
who suffers from some form of mental illness.
3
21765
3488
tko pati od nekog oblika mentalne bolesti.
00:25
Yeah. I thought so. Not surprised.
4
25253
2784
Da. Tako sam i mislio. Nisam iznenađen.
00:28
And raise your hand if you think that
5
28037
2295
Također, dignite ruku ako mislite da
00:30
basic research on fruit flies has anything to do
6
30332
2825
su istraživanja na vinskoj mušici u ikakvoj vezi
00:33
with understanding mental illness in humans.
7
33157
4462
s razumijevanjem mentalnih bolesti kod ljudi.
00:37
Yeah. I thought so. I'm also not surprised.
8
37619
2793
Da... Tako sam i mislio. Ponovno, nisam iznenađen.
00:40
I can see I've got my work cut out for me here.
9
40412
3320
Vidim da kao publika predstavljate plodno tlo za mene.
00:43
As we heard from Dr. Insel this morning,
10
43732
2588
Kao što ste jutros čuli od dr. Insel,
00:46
psychiatric disorders like autism, depression and schizophrenia
11
46320
4213
psihijatrijski poremećaji kao što su autizam, depresija i shizofrenija
00:50
take a terrible toll on human suffering.
12
50533
2875
u velikoj mjeri doprinose ljudskoj patnji.
00:53
We know much less about their treatment
13
53408
3213
Malo nam je toga poznato o liječenju
00:56
and the understanding of their basic mechanisms
14
56621
2606
i razumijevanju osnovnih mehanizama tih poremećaja
00:59
than we do about diseases of the body.
15
59227
2619
u usporedbi s onim što znamo o fizičkim bolestima.
01:01
Think about it: In 2013,
16
61846
2643
Razmislite malo o tome, u 2013. godini,
01:04
the second decade of the millennium,
17
64489
1955
u drugom desetljeću ovoga milenija,
01:06
if you're concerned about a cancer diagnosis
18
66444
2365
ako ste zabrinuti da bolujete od karcinoma
01:08
and you go to your doctor, you get bone scans,
19
68809
2519
i odete liječniku, pregledaju vam kosti,
01:11
biopsies and blood tests.
20
71328
2928
naprave biopsiju i krvne pretrage.
01:14
In 2013, if you're concerned about a depression diagnosis,
21
74256
3865
U 2013. godini, ako ste zabrinuti da bolujete od depresije
01:18
you go to your doctor, and what do you get?
22
78121
1963
i odete liječniku, što dobijete?
01:20
A questionnaire.
23
80084
1987
Upitnik.
01:22
Now, part of the reason for this is that we have
24
82071
2429
Jedan od razloga je taj što imamo
01:24
an oversimplified and increasingly outmoded view
25
84500
3823
vrlo pojednostavljen i zastario pogled
01:28
of the biological basis of psychiatric disorders.
26
88323
3887
na biološku osnovu psihijatrijskih poremećaja.
01:32
We tend to view them --
27
92210
1243
Obično smatramo,
01:33
and the popular press aids and abets this view --
28
93453
2845
i to je pogled koji se promovira i u medijima,
01:36
as chemical imbalances in the brain,
29
96298
3016
da se radi o kemijskoj neravnoteži u mozgu,
01:39
as if the brain were some kind of bag of chemical soup
30
99314
3684
kao da je mozak kotao kemijske juhe
01:42
full of dopamine, serotonin and norepinephrine.
31
102998
4200
od dopamina, serotonina i noradrenalina.
01:47
This view is conditioned by the fact
32
107198
2327
Takav stav posljedica je činjenice
01:49
that many of the drugs that are prescribed to treat these disorders,
33
109525
3406
da mnogi lijekovi koji se prepisuju u liječenju tih poremećaja,
01:52
like Prozac, act by globally changing brain chemistry,
34
112931
4671
kao što je Prozac, djeluju na principu mijenjanja "kemije mozga",
01:57
as if the brain were indeed a bag of chemical soup.
35
117602
3976
kao da je mozak uistinu kotao kemijske juhe.
02:01
But that can't be the answer,
36
121578
1901
Ali to ne može biti rješenje
02:03
because these drugs actually don't work all that well.
37
123479
3237
jer ti lijekovi zapravo i ne djeluju tako dobro.
02:06
A lot of people won't take them, or stop taking them,
38
126716
3176
Mnogi ih ne žele uzimati ili će ih prestati uzimati
02:09
because of their unpleasant side effects.
39
129892
2657
zbog neugodnih nuspojava koje izazivaju.
02:12
These drugs have so many side effects
40
132549
2060
Ti lijekovi imaju toliko nuspojava
02:14
because using them to treat a complex psychiatric disorder
41
134609
3956
jer njihovo korištenje u liječenju složenih psihijatrijskih poremećaja
02:18
is a bit like trying to change your engine oil
42
138565
2689
može se usporediti s mijenjanjem motornog ulja
02:21
by opening a can and pouring it all over the engine block.
43
141254
4113
tako da otvorite limenku ulja i izlijete je preko cijelog motora.
02:25
Some of it will dribble into the right place,
44
145367
2150
Nešto će u konačnici završiti na pravom mjestu,
02:27
but a lot of it will do more harm than good.
45
147517
3101
ali većina će napraviti više štete nego koristi.
02:30
Now, an emerging view
46
150618
2238
Novi pogled,
02:32
that you also heard about from Dr. Insel this morning,
47
152856
2950
o kojem ste također čuli jutros od dr. Insel,
02:35
is that psychiatric disorders are actually
48
155806
2570
jest taj da su psihijatrijski poremećaji zapravo
02:38
disturbances of neural circuits that mediate
49
158376
3474
smetnje u neurološkim sklopovima koji sudjeluju u posredovanju
02:41
emotion, mood and affect.
50
161850
3519
emocija, raspoloženja i afekata.
02:45
When we think about cognition,
51
165369
1762
Kada govorimo o kogniciji,
02:47
we analogize the brain to a computer. That's no problem.
52
167131
3576
poistovjećujemo mozak s računalom. To nije problem.
02:50
Well it turns out that the computer analogy
53
170707
2581
Ali ispostavilo se da analogija s računalom
02:53
is just as valid for emotion.
54
173288
2383
vrijedi i u slučaju emocija.
02:55
It's just that we don't tend to think about it that way.
55
175671
2786
Samo ne razmišljamo o tome na taj način.
02:58
But we know much less about the circuit basis
56
178457
3283
Malo nam je poznato o neurološkim sklopovima
03:01
of psychiatric disorders
57
181740
1899
kao o osnovi psihijatrijskih poremećaja
03:03
because of the overwhelming dominance
58
183639
2070
zbog velike dominacije
03:05
of this chemical imbalance hypothesis.
59
185709
3352
spomenute hipoteze o kemijskoj neravnoteži.
03:09
Now, it's not that chemicals are not important
60
189061
3827
Ne tvrdim da kemijske tvari nisu važne
03:12
in psychiatric disorders.
61
192888
1537
u psihijatrijskim poremećajima.
03:14
It's just that they don't bathe the brain like soup.
62
194425
3972
Stvar je u tome što one ne oplahnjuju mozak kao juha.
03:18
Rather, they're released in very specific locations
63
198397
3649
Umjesto toga, otpuštaju se na vrlo određenim lokacijama
03:22
and they act on specific synapses
64
202046
2725
i djeluju na određene sinapse
03:24
to change the flow of information in the brain.
65
204771
3688
kako bi se promijenio dotok informacija u mozak.
03:28
So if we ever really want to understand
66
208459
2437
Dakle, ako stvarno želimo razumjeti
03:30
the biological basis of psychiatric disorders,
67
210896
2705
biološku osnovu psihijatrijskih poremećaja,
03:33
we need to pinpoint these locations in the brain
68
213601
3032
moramo točno locirati mjesta u mozgu
03:36
where these chemicals act.
69
216633
1734
na koja spomenute kemijske tvari djeluju.
03:38
Otherwise, we're going to keep pouring oil all over our mental engines
70
218367
3479
Inače ćemo nastaviti prolijevati ulje po našim mentalnim motorima
03:41
and suffering the consequences.
71
221846
2957
i trpjeti posljedice.
03:44
Now to begin to overcome our ignorance
72
224803
3059
U nastojanju da prevladamo svoje neznanje
03:47
of the role of brain chemistry in brain circuitry,
73
227862
3534
o ulozi kemije mozga u neurološkim sklopovima,
03:51
it's helpful to work on what we biologists call
74
231396
2680
korisno je raditi na onome što mi biolozi nazivamo
03:54
"model organisms,"
75
234076
1579
modelnim organizmima,
03:55
animals like fruit flies and laboratory mice,
76
235655
3334
životinjama kao što su vinske mušice i laboratorijski miševi,
03:58
in which we can apply powerful genetic techniques
77
238989
3425
pri čemu možemo primijeniti genetičke metode
04:02
to molecularly identify and pinpoint
78
242414
3625
da identificiramo na molekularnoj razini i točno odredimo
04:06
specific classes of neurons,
79
246039
1563
specifične klase neurona,
04:07
as you heard about in Allan Jones's talk this morning.
80
247602
2903
kao što ste ujutro čuli u govoru Allana Jonesa.
04:10
Moreover, once we can do that,
81
250505
2461
Štoviše, kad to postane moguće,
04:12
we can actually activate specific neurons
82
252966
2749
moći ćemo i aktivirati specifične neurone
04:15
or we can destroy or inhibit the activity of those neurons.
83
255715
4211
ili ih uništiti ili blokirati njihovu aktivnost.
04:19
So if we inhibit a particular type of neuron,
84
259926
2714
Dakle, ako blokiramo određeni tip neurona
04:22
and we find that a behavior is blocked,
85
262640
2465
i odredimo da je neki obrazac ponašanja blokiran,
04:25
we can conclude that those neurons
86
265105
2214
možemo zaključiti kako su upravo ti neuroni
04:27
are necessary for that behavior.
87
267319
2964
potrebni za određeni obrazac ponašanja.
04:30
On the other hand, if we activate a group of neurons
88
270283
2382
S druge strane, ako aktiviramo skupinu neurona
04:32
and we find that that produces the behavior,
89
272665
2814
i otkrijemo da to uzrokuje novi obrazac ponašanja,
04:35
we can conclude that those neurons are sufficient for the behavior.
90
275479
4074
možemo zaključiti da su ti neuroni dostatni za javljanje tog obrasca.
04:39
So in this way, by doing this kind of test,
91
279553
3009
Dakle, na ovaj način, provodeći navedena testiranja
04:42
we can draw cause and effect relationships
92
282562
3523
možemo uspostaviti odnos uzorka i posljedice
04:46
between the activity of specific neurons
93
286085
2356
između aktivnosti određenih neurona
04:48
in particular circuits and particular behaviors,
94
288441
2913
u pojedinim sklopovima i određenih obrazaca ponašanja,
04:51
something that is extremely difficult, if not impossible,
95
291354
2437
nešto što je vrlo teško, ako ne i nemoguće,
04:53
to do right now in humans.
96
293791
5051
u ovom trenutku kod ljudi.
04:58
But can an organism like a fruit fly, which is --
97
298842
2837
No može li organizam kao što je vinska mušica, koja je --
05:01
it's a great model organism
98
301679
2200
odličan modelni organizam
05:03
because it's got a small brain,
99
303879
2538
zato što ima mali mozak,
05:06
it's capable of complex and sophisticated behaviors,
100
306417
3787
sposobna je za složena i sofisticirana ponašanja,
05:10
it breeds quickly, and it's cheap.
101
310204
3150
brzo se razmnožava i jeftina je...
05:13
But can an organism like this
102
313354
1795
Može li nas takav organizam
05:15
teach us anything about emotion-like states?
103
315149
3843
naučiti nešto o stanjima vezanima uz emocije?
05:18
Do these organisms even have emotion-like states,
104
318992
3300
Imaju li ti organizmi uopće emocije
05:22
or are they just little digital robots?
105
322292
3363
ili su samo nalik malim digitalnim robotima?
05:25
Charles Darwin believed that insects have emotion
106
325655
3200
Charles Darwin vjerovao je da insekti imaju emocije
05:28
and express them in their behaviors, as he wrote
107
328855
2550
i izražavaju ih svojim ponašanjem, kako je napisao
05:31
in his 1872 monograph on the expression of the emotions in man and animals.
108
331405
5193
1872. godine u svojoj monografiji o izražavanju emocija kod ljudi i životinja.
05:36
And my eponymous colleague, Seymour Benzer, believed it as well.
109
336598
3519
Isto je i vjerovao moj istoimeni kolega, Seymour Benzer.
05:40
Seymour is the man that introduced the use of drosophila
110
340117
3414
Seymour je čovjek koji je uveo Drosophilu
05:43
here at CalTech in the '60s as a model organism
111
343531
3523
kao modelni organizam ovdje na CalTech u 60-ima
05:47
to study the connection between genes and behavior.
112
347054
3597
za istraživanje veze između gena i ponašanja.
05:50
Seymour recruited me to CalTech in the late 1980s.
113
350651
3607
Seymour me zaposlio na CalTechu u kasnim 1980-ima.
05:54
He was my Jedi and my rabbi while he was here,
114
354258
4434
Bio je moj Jedi i moj rabin kad je bio ovdje
05:58
and Seymour taught me both to love flies
115
358692
2388
i Seymour me naučio kako voljeti mušice
06:01
and also to play with science.
116
361080
3049
i istovremeno se igrati sa znanošću.
06:04
So how do we ask this question?
117
364129
3116
Kako dakle postaviti to pitanje?
06:07
It's one thing to believe that flies have emotion-like states,
118
367245
4060
Jedna je stvar vjerovati da mušice imaju emocije,
06:11
but how do we actually find out whether that's true or not?
119
371305
3163
ali kako zapravo možemo saznati je li to istina?
06:14
Now, in humans we often infer emotional states,
120
374468
3950
Kod ljudi, često zaključujemo o emocionalnom stanju,
06:18
as you'll hear later today, from facial expressions.
121
378418
3905
kao što ćete čuti kasnije danas, na temelju izraza lica.
06:22
However, it's a little difficult to do that in fruit flies.
122
382323
3720
Međutim, malo je teže napraviti isto s vinskim mušicama.
06:26
(Laughter)
123
386043
3313
(smijeh)
06:29
It's kind of like landing on Mars
124
389356
3137
To je kao da slijećete na Mars
06:32
and looking out the window of your spaceship
125
392493
2705
i gledajući kroz prozor svemirskog broda
06:35
at all the little green men who are surrounding it
126
395198
2470
na sve "male zelene" koji ga okružuju,
06:37
and trying to figure out, "How do I find out
127
397668
2406
pokušavate shvatiti "Kako mogu saznati
06:40
if they have emotions or not?"
128
400074
2355
imaju li oni emocije ili ne?"
06:42
What can we do? It's not so easy.
129
402429
3543
Što možemo učiniti? Nije tako lagano.
06:45
Well, one of the ways that we can start
130
405972
2185
Jedan od načina na koji možemo početi
06:48
is to try to come up with some general characteristics
131
408157
4125
jest pokušati s nekim općim značajkama
06:52
or properties of emotion-like states
132
412282
3748
ili obilježjima emocija,
06:56
such as arousal, and see if we can identify
133
416030
3464
kao što je uzbuđenje, i vidjeti možemo li identificirati
06:59
any fly behaviors that might exhibit some of those properties.
134
419494
5376
bilo koje ponašanje mušice koje pokazuje neka od tih obilježja.
07:04
So three important ones that I can think of
135
424870
2820
Tri važna obilježja kojih se mogu sjetiti
07:07
are persistence, gradations in intensity, and valence.
136
427690
4672
su upornost, gradacije u intenzitetu i valencija.
07:12
Persistence means long-lasting.
137
432362
2334
Upornost u kontekstu dugotrajnog.
07:14
We all know that the stimulus that triggers an emotion
138
434696
3961
Svi znamo da podražaj koji aktivira emociju
07:18
causes that emotion to last long after the stimulus is gone.
139
438657
5016
uzrokuje trajanje emocije i nakon prestanka samog podražaja.
07:23
Gradations of intensity means what it sounds like.
140
443673
3090
Gradacija intenziteta znači baš ono kao što i zvuči.
07:26
You can dial up the intensity or dial down the intensity of an emotion.
141
446763
4583
Možete povisiti ili sniziti intenzitet emocija.
07:31
If you're a little bit unhappy, the corners of your mouth
142
451346
2600
Ako ste pomalo nesretni, uglovi vaših usana
07:33
turn down and you sniffle,
143
453946
1687
okrenu se prema dolje i šmrčete,
07:35
and if you're very unhappy, tears pour down your face
144
455633
3138
a ako ste vrlo nesretni, lijete suze
07:38
and you might sob.
145
458771
1832
i možda zajecate.
07:40
Valence means good or bad, positive or negative.
146
460603
4379
Valencija znači dobro ili loše, pozitivno ili negativno.
07:44
So we decided to see if flies could be provoked into showing
147
464982
4452
Odlučili smo vidjeti možemo li izazvati mušice da pokažu
07:49
the kind of behavior that you see
148
469434
2451
neke od obrazaca ponašanja koja možete vidjeti
07:51
by the proverbial wasp at the picnic table,
149
471885
2810
kod ose za stolom na pikniku,
07:54
you know, the one that keeps coming back to your hamburger
150
474695
2685
znate, one koja se uporno vraća na vaš hamburger
07:57
the more vigorously you try to swat it away,
151
477380
2529
što se više trudite otjerati je
07:59
and it seems to keep getting irritated.
152
479909
2284
i čini se da je sve uzrujanija.
08:02
So we built a device, which we call a puff-o-mat,
153
482193
3647
Sastavili smo uređaj, koji mi zovemo "puhomat",
08:05
in which we could deliver little brief air puffs to fruit flies
154
485840
4345
kojim smo mogli isporučiti kratku stuju zraka usmjerenu na vinske mušice
08:10
in these plastic tubes in our laboratory bench
155
490185
2776
u plastičnim cjevčicama u našem laboratoriju
08:12
and blow them away.
156
492961
1725
te ih otpuhati.
08:14
And what we found is that if we gave these flies
157
494686
3239
Doznali smo da ako izložimo mušice
08:17
in the puff-o-mat several puffs in a row,
158
497925
2848
u "puhomatu" uzastopnim kratkim strujanjima zraka,
08:20
they became somewhat hyperactive
159
500773
2689
one postanu, recimo, hiperaktivne
08:23
and continued to run around for some time after the air puffs actually stopped
160
503462
4435
i nastave letjeti uokolo još neko vrijeme i nakon što je strujanje zraka prestalo
08:27
and took a while to calm down.
161
507897
2864
te im je potrebno neko vrijeme da se smire.
08:30
So we quantified this behavior
162
510761
2189
Kvantificirali smo to ponašanje
08:32
using custom locomotor tracking software
163
512950
3012
prilagođenim programom za lokomotorno praćenje
08:35
developed with my collaborator Pietro Perona,
164
515962
2800
razvijenim s mojim suradnikom Pietrom Peronom,
08:38
who's in the electrical engineering division here at CalTech.
165
518762
3612
koji radi u elektrotehničkom odjelu ovdje na CalTechu.
08:42
And what this quantification showed us is that,
166
522374
2814
Ta kvantifikacija pokazala nam je da
08:45
upon experiencing a train of these air puffs,
167
525188
3224
nakon izlaganja kontinuiranim kratkim strujanjima zraka
08:48
the flies appear to enter a kind of state of hyperactivity
168
528412
4314
mušice naizgled postanu hiperaktivne,
08:52
which is persistent, long-lasting,
169
532726
2598
što je stabilno, dugotrajno stanje
08:55
and also appears to be graded.
170
535324
2504
koje se također čini gradiranim.
08:57
More puffs, or more intense puffs,
171
537828
2859
Više strujanja, ili intenzivnija strujanja,
09:00
make the state last for a longer period of time.
172
540687
3913
uzrokuju dulje stanje hiperaktivnosti.
09:04
So now we wanted to try to understand something
173
544600
2036
Zatim smo htjeli saznati nešto o
09:06
about what controls the duration of this state.
174
546636
3714
načinu kontrole trajanja tog stanja.
09:10
So we decided to use our puff-o-mat
175
550350
2851
Odlučili smo koristit naš "puhomat"
09:13
and our automated tracking software
176
553201
2055
i automatizirani program za praćenje
09:15
to screen through hundreds of lines of mutant fruit flies
177
555256
3782
za provjeru stotine linija mutanata vinske mušice da bismo vidjeli
09:19
to see if we could find any that showed abnormal responses to the air puffs.
178
559038
5079
možemo li pronaći mutante koji pokazuju nenormalne odgovore na strujanja zraka.
09:24
And this is one of the great things about fruit flies.
179
564117
2347
Jedna od odličnih stvari vezano uz vinsku mušicu.
09:26
There are repositories where you can just pick up the phone
180
566464
2793
Postoje repozitoriji gdje možete samo okrenuti telefonski broj
09:29
and order hundreds of vials of flies of different mutants
181
569257
3641
i naručiti stotine bočica s različitim mutantima vinske mušice,
09:32
and screen them in your assay and then find out
182
572898
2172
analizirati ih i otkriti
09:35
what gene is affected in the mutation.
183
575070
3319
koji je gen promijenjen mutacijom.
09:38
So doing the screen, we discovered one mutant
184
578389
3512
Dakle, tijekom analize otkrili smo jednog mutanta
09:41
that took much longer than normal to calm down
185
581901
3474
kojem je bilo potrebno mnogo dulje da se smiri
09:45
after the air puffs,
186
585375
2277
nakon strujanja zraka
09:47
and when we examined the gene that was affected in this mutation,
187
587652
3950
i kada smo provjerili gen koji je promijenjen tom mutacijom
09:51
it turned out to encode a dopamine receptor.
188
591602
3605
ispostavilo se da taj gen kodira dopaminski receptor.
09:55
That's right -- flies, like people, have dopamine,
189
595207
3011
Da, tako je - mušice, kao i ljudi, imaju dopamin,
09:58
and it acts on their brains and on their synapses
190
598218
2772
koji djeluje na njihov mozak i njihove sinapse
10:00
through the same dopamine receptor molecules
191
600990
2550
preko istih dopaminskih receptora
10:03
that you and I have.
192
603540
2389
koje imamo i vi i ja.
10:05
Dopamine plays a number of important functions in the brain,
193
605929
3486
Dopamin ima mnogo važnih funkcija u mozgu,
10:09
including in attention, arousal, reward,
194
609415
3113
uključujući one vezane uz pozornost, uzbuđenje, nagradu,
10:12
and disorders of the dopamine system have been linked
195
612528
3413
a poremećaji dopaminskog sustava povezani su
10:15
to a number of mental disorders including drug abuse,
196
615941
3100
s brojnim mentalnim poremećajima uključujući zloupotrebu droga,
10:19
Parkinson's disease, and ADHD.
197
619041
4234
Parkinsonovu bolest te ADHD (poremećaj pozornosti s hiperaktivnošću).
10:23
Now, in genetics, it's a little counterintuitive.
198
623275
2790
U genetici to je pomalo protuintuitivno.
10:26
We tend to infer the normal function of something
199
626065
3260
Zaključujemo o normalnoj funkciji nečega
10:29
by what doesn't happen when we take it away,
200
629325
3710
na temelju onoga što se ne dogodi kada to oduzmemo,
10:33
by the opposite of what we see when we take it away.
201
633035
3003
na temelju suprotnog od onog što vidimo kada to oduzmemo.
10:36
So when we take away the dopamine receptor
202
636038
3013
Dakle, kada odstranimo domapinski receptor
10:39
and the flies take longer to calm down,
203
639051
2557
i mušicama je potrebno više vremena da se smire,
10:41
from that we infer that the normal function of this receptor and dopamine
204
641608
3846
zaključit ćemo da je normalna funkcija tog receptora i dopamina
10:45
is to cause the flies to calm down faster after the puff.
205
645454
4485
vezana uz brže smirivanje mušica nakon što su izložene struji zraka.
10:49
And that's a bit reminiscent of ADHD,
206
649939
2950
To pomalo podsjeća na ADHD,
10:52
which has been linked to disorders of the dopamine system in humans.
207
652889
3975
koji je povezan s poremećajima dopaminskog sustava u ljudi.
10:56
Indeed, if we increase the levels of dopamine in normal flies
208
656864
4606
Doista, ako povećamo razinu dopamina u normalnih mušica
11:01
by feeding them cocaine
209
661470
1710
hraneći ih kokainom,
11:03
after getting the appropriate DEA license
210
663180
2972
nakon što smo dobili odgovarajuću dozvolu od DEA-e
11:06
— oh my God -- (Laughter) —
211
666152
4000
- o moj Bože - (smijeh)
11:10
we find indeed that these cocaine-fed flies
212
670152
3172
došli smo do saznanja da se kokainom hranjene mušice
11:13
calm down faster than normal flies do,
213
673324
3042
doista smire brže u usporedbi s normalnima,
11:16
and that's also reminiscent of ADHD,
214
676366
3199
i to također podsjeća na ADHD,
11:19
which is often treated with drugs like Ritalin
215
679565
2045
koji se često liječi lijekovima kao što su Ritalin
11:21
that act similarly to cocaine.
216
681610
3019
koji djeluje na sličan način kao kokain.
11:24
So slowly I began to realize that what started out
217
684629
3149
Tako sam polako počeo shvaćati da bi ono što smo započeli
11:27
as a rather playful attempt to try to annoy fruit flies
218
687778
3649
kao prilično razigran pokušaj da uzrujamo vinske mušice
11:31
might actually have some relevance to a human psychiatric disorder.
219
691427
3976
zapravo moglo biti važno za psihijatrijske poremećaje kod ljudi.
11:35
Now, how far does this analogy go?
220
695403
2226
Što sve možemo obuhvatiti ovom analogijom?
11:37
As many of you know, individuals afflicted with ADHD
221
697629
3122
Kao što mnogi od vas znaju, pojedinci koju boluju od ADHD-a
11:40
also have learning disabilities.
222
700751
2337
također imaju i poteškoće u učenju.
11:43
Is that true of our dopamine receptor mutant flies?
223
703088
3566
Vrijedi li isto i za naše mušice s mutiranim dopaminskim receptorom?
11:46
Remarkably, the answer is yes.
224
706654
2720
Iznenađujuće, odgovor je da.
11:49
As Seymour showed back in the 1970s,
225
709374
2628
Kao što je Seymour prezentirao u 1970-ima,
11:52
flies, like songbirds, as you just heard,
226
712002
2451
mušice, poput ptica pjevica, kao što ste upravo čuli,
11:54
are capable of learning.
227
714453
1733
imaju sposobnost učenja.
11:56
You can train a fly to avoid an odor, shown here in blue,
228
716186
4443
Možete obučiti mušicu da izbjegava određeni miris, što je prikazano plavom bojom,
12:00
if you pair that odor with a shock.
229
720629
2388
ako povežete taj miris sa šokom.
12:03
Then when you give those trained flies the chance to choose
230
723017
3384
Kada date tim obučenim mušicama da biraju
12:06
between a tube with the shock-paired odor and another odor,
231
726401
3154
između cijevi s mirisom koji je povezan sa šokom i nekim drugim mirisom,
12:09
it avoids the tube containing the blue odor that was paired with shock.
232
729555
4200
izbjegavat će cjevčicu koja sadrži plavi miris koji je povezan sa šokom.
12:13
Well, if you do this test on dopamine receptor mutant flies,
233
733755
3502
Ali ako provedete isti test na mušicama s mutiranim dopaminskim receptorom,
12:17
they don't learn. Their learning score is zero.
234
737257
2465
one neće naučiti ništa. Konačna ocjena je nula.
12:19
They flunk out of CalTech.
235
739722
3811
Izbačene su s CalTecha.
12:23
So that means that these flies have two abnormalities,
236
743533
4748
Dakle, to znači da te mušice imaju dvije abnormalnosti,
12:28
or phenotypes, as we geneticists call them,
237
748281
3050
ili fenotipa, kao što ih mi genetičari nazivamo,
12:31
that one finds in ADHD: hyperactivity and learning disability.
238
751331
5512
koji su prisutni i kod ADHD-a: hiperaktivnost i poteškoće u učenju.
12:36
Now what's the causal relationship, if anything, between these phenotypes?
239
756843
4363
Koja je uzročno-posljedična veza, ako postoji, između tih fenotipova?
12:41
In ADHD, it's often assumed that the hyperactivity
240
761206
3913
Kod ADHD-a često se pretpostavlja da hiperaktivnost
12:45
causes the learning disability.
241
765119
1906
uzrokuje poteškoće u učenju.
12:47
The kids can't sit still long enough to focus, so they don't learn.
242
767025
3719
Djeca ne mogu biti mirna dovoljno dugo da se koncentriraju, pa tako ne mogu učiti.
12:50
But it could equally be the case that it's the learning disabilities
243
770744
3296
Ali jednako bi tako mogao biti slučaj da teškoće u učenju
12:54
that cause the hyperactivity.
244
774040
1872
uzrokuju hiperaktivnost.
12:55
Because the kids can't learn, they look for other things to distract their attention.
245
775912
4470
Budući da djeca ne mogu učiti, traže druge stvari da im skrenu pozornost.
13:00
And a final possibility is that there's no relationship at all
246
780382
3057
I posljednja je mogućnost da povezanost
13:03
between learning disabilities and hyperactivity,
247
783439
2404
između poteškoća u učenju i hiperaktivnosti uopće ne postoji,
13:05
but that they are caused by a common underlying mechanism in ADHD.
248
785843
4915
već da su uzrokovani zajedničkim temeljnim mehanizmom ADHD-a.
13:10
Now people have been wondering about this for a long time
249
790758
2342
To je već dugo predmet rasprava vezano
13:13
in humans, but in flies we can actually test this.
250
793100
3488
za ljude, ali kod mušica to možemo i testirati.
13:16
And the way that we do this is to delve deeply into the mind
251
796588
3084
Način na koji to možemo učiniti jest zaviriti duboko u um
13:19
of the fly and begin to untangle its circuitry using genetics.
252
799672
4266
mušice i početi raspetljavati sklopove pomoću genetike.
13:23
We take our dopamine receptor mutant flies
253
803938
2462
Uzmemo mušice s mutiranim dopamintskim receptorom
13:26
and we genetically restore, or cure, the dopamine receptor
254
806400
4564
i genetički obnovimo, ili izliječimo, dopaminski receptor
13:30
by putting a good copy of the dopamine receptor gene
255
810964
3235
umetanjem dobre kopije gena za dopaminski receptor
13:34
back into the fly brain.
256
814199
2051
u mozak mušice.
13:36
But in each fly, we put it back only into certain neurons
257
816250
3835
Ali u svakoj ga mušici umetnemo jedino u određene neurone,
13:40
and not in others, and then we test each of these flies
258
820085
3714
a u druge ne, i zatim analiziramo svaku od mušica
13:43
for their ability to learn and for hyperactivity.
259
823799
3668
i njihovu sposobnost učenja i hiperaktivnost.
13:47
Remarkably, we find we can completely dissociate these two abnormalities.
260
827467
4818
Izuzetno, spoznali smo da u potpunosti možemo razdvojiti te dvije anomalije.
13:52
If we put a good copy of the dopamine receptor back
261
832285
2663
Ako stavimo dobru kopiju dopaminskog receptora u
13:54
in this elliptical structure called the central complex,
262
834948
2961
eliptičnu strukturu zvanu središnji kompleks,
13:57
the flies are no longer hyperactive, but they still can't learn.
263
837909
4077
mušice nisu više hiperaktivne, ali još nemaju sposobnost učenja.
14:01
On the other hand, if we put the receptor back in a different structure
264
841986
2726
S druge strane, ako stavimo receptor u drugačiju strukturu,
14:04
called the mushroom body,
265
844712
1518
prednji asocijativni centar,
14:06
the learning deficit is rescued, the flies learn well,
266
846230
3085
počeškoće u učenju su otklonjene, mušice mogu učiti,
14:09
but they're still hyperactive.
267
849315
1830
ali su i dalje hiperaktivne.
14:11
What that tells us is that dopamine
268
851145
2250
To nam govori da dopamin
14:13
is not bathing the brain of these flies like soup.
269
853395
3392
ne oplahnjuje mozak tih mušica kao juha.
14:16
Rather, it's acting to control two different functions
270
856787
3162
Umjesto toga, on kontrolira dvije različite funkcije
14:19
on two different circuits,
271
859949
1634
na dva različita sklopa,
14:21
so the reason there are two things wrong with our dopamine receptor flies
272
861583
3904
pa razlog postojanja dviju stvari koje nisu u redu s mušicama s mutiranim dopaminskim receptorom
14:25
is that the same receptor is controlling two different functions
273
865487
4175
leži u činjenici da jedan receptor kontrolira dvije različite funkcije
14:29
in two different regions of the brain.
274
869662
2863
u dvije različite regije mozga.
14:32
Whether the same thing is true in ADHD in humans
275
872525
3062
Vrijedi li ista stvar i za ADHD kod ljudi,
14:35
we don't know, but these kinds of results
276
875587
2376
ne znamo, ali rezultati poput ovih
14:37
should at least cause us to consider that possibility.
277
877963
3477
trebali bi nas barem potaknuti da razmotrimo tu mogućnost.
14:41
So these results make me and my colleagues more convinced than ever
278
881440
3973
Dakle, ovi rezultati uvjerili su mene i moje kolege više nego ikad
14:45
that the brain is not a bag of chemical soup,
279
885413
3412
da mozak nije samo kotao kemijske juhe
14:48
and it's a mistake to try to treat complex psychiatric disorders
280
888825
3527
i da je pogrešno pokušavati liječiti složene psihijatrijske poremećaje
14:52
just by changing the flavor of the soup.
281
892352
2711
mijenjajući samo okus juhe.
14:55
What we need to do is to use our ingenuity and our scientific knowledge
282
895063
4217
Trebamo iskoristiti svoju domišljatost i svoje znanstvene spoznaje
14:59
to try to design a new generation of treatments
283
899280
2708
te pokušati osmisliti novu generaciju tretmana
15:01
that are targeted to specific neurons and specific regions of the brain
284
901988
4288
koji su usmjereni na određene neurone i specifične regije mozga
15:06
that are affected in particular psychiatric disorders.
285
906276
3338
koji su pogođeni kod određenih psihijatrijskih poremećaja.
15:09
If we can do that, we may be able to cure these disorders
286
909614
3200
Ako to možemo učiniti, mogli bismo izliječiti te bolesti
15:12
without the unpleasant side effects,
287
912814
2047
bez neugodnih nuspojava,
15:14
putting the oil back in our mental engines,
288
914861
2746
dolijevajući ulje u naše mentalne motore
15:17
just where it's needed. Thank you very much.
289
917607
3184
točno tamo gdje je to potrebno. Puno hvala.
O ovoj web stranici

Ova stranica će vas upoznati s YouTube videozapisima koji su korisni za učenje engleskog jezika. Vidjet ćete lekcije engleskog koje vode vrhunski profesori iz cijelog svijeta. Dvaput kliknite na engleske titlove prikazane na svakoj video stranici da biste reproducirali video s tog mjesta. Titlovi se pomiču sinkronizirano s reprodukcijom videozapisa. Ako imate bilo kakvih komentara ili zahtjeva, obratite nam se putem ovog obrasca za kontakt.

https://forms.gle/WvT1wiN1qDtmnspy7