Can you transplant a head to another body? - Max G. Levy

Translator: María Herrero Prado Reviewer: traduceTED USC

On March 14th, 1970, Robert White and his team carted two small monkeys

O 14 de marzo de 1970, Robert White e o seu equipo levaron dous pequenos monos

into an operating room.

a unha sala de operacións.

The neurosurgeon lay on the verge of an ambitious experiment,

O neurocirurxián estaba ante un ambicioso experimento,

decades in the making, which was bizarre,

que levaba décadas preparando, estraño,

if not pulled straight from his own fever dream.

se non sacado directamente dun soño febril.

White’s objective?

O seu obxectivo?

Connect the head of Monkey A to the body of Monkey B,

Conectar a cabeza do mono A ao corpo do mono B,

in what he considered a whole-body transplant.

o que consideraba un transplante de corpo enteiro.

White’s ultimate goal was to one day perform this surgery on humans.

O obxectivo final de White era facer esta cirurxía en humanos algún día.

While disturbing, the idea of a body transplant

Aínda que perturbadora, a idea dun transplante de corpo

raises ethical, biological, and philosophical questions—

expón cuestións éticas, biolóxicas e filosóficas

on the nature of life and the limits of science—

sobre a natureza da vida e os límites da ciencia

that are still discussed today.

que aínda hoxe se discuten.

But first, is it even medically possible?

Pero primeiro: é posible desde o punto de vista médico?

White's surgery faced several technical hurdles.

A cirurxía de White enfrontouse a varios obstáculos técnicos.

For one thing, it guaranteed paralysis

Por unha banda, garantía a parálise,

as no doctor then— or now— could reconnect a severed spinal cord.

xa que ningún médico podería (nin pode) conectar unha medula espiñal cortada.

But White, a practicing neurosurgeon,

Pero White, un neurocirurxián en exercicio,

thought the surgery could be life-saving

pensou que a cirurxía podería salvar a vida

for his patients with spinal cord injuries or progressive mobility diseases like ALS.

aos seus pacientes con lesións da medula espiñal

ou enfermidades de mobilidade progresivas como a ELA.

These patients often face multi-organ failures and paralysis,

Estes pacientes adoitan sufrir fallos multiorgánicos e parálises,

so with a body transplant,

así que, cun transplante de corpo,

he hoped to save their lives by replacing all of their organs at once.

esperaba salvarlles a vida substituíndo todos os seus órganos á vez.

But paralysis wasn't the only challenge.

Pero a parálise non era o único problema.

Due to their high energy demands,

Debido á súa alta demanda de enerxía,

brain cells require a constant supply of oxygenated blood to survive.

as células cerebrais requiren unha subministración constante

de sangue osixenado para sobrevivir.

Yet the transplant surgery would likely interrupt the brain’s oxygen flow

Non obstante, a cirurxía interrompería o fluxo de osíxeno do cerebro

for hours.

durante horas.

But White had an idea.

Pero White tivo unha idea.

When the brain is cold,

Cando o cerebro está frío,

its metabolism slows down and it relies less on oxygen.

o metabolismo retárdase e depende menos do osíxeno.

Experimenting on dogs and monkeys,

Experimentando con cans e monos,

White optimized a brain-cooling technique

optimizou unha técnica de arrefriado do cerebro

where the brain’s blood flow was selectively chilled and halted,

onde o fluxo sanguíneo do cerebro se arrefriaba e detía selectivamente

while the rest of the body’s blood remained warm and circulated.

mentres o resto do sangue do corpo se mantiña quente e circulaba.

Then, in 1964, White successfully cooled the brain of a human patient

En 1964, White conseguiu arrefriar o cerebro dun paciente humano

with a life-threatening brain tumor into “suspended animation” at 11°C.

cun tumor cerebral potencialmente mortal en “animación suspendida” a 11 °C.

Whereas normally the surgical team would have just 3 to 5 minutes

Mentres que normalmente o equipo cirúrxico tería só de 3 a 5 minutos

to remove the tumor,

para extirpar o tumor,

with this new technique,

con esta nova técnica,

they operated for over an hour without causing damage.

operaron durante máis dunha hora sen causar danos.

Brain cooling revolutionized the field of neurosurgery

O arrefriado cerebral revolucionou o campo da neurocirurxía

and put White one step closer to his body transplant goal.

e puxo a White un paso máis preto do seu obxectivo de transplante de corpo.

But this vision was fraught with serious ethical concerns.

Pero esta visión nubrouse polos graves problemas éticos.

What conditions would justify such an experimental surgery,

Que condicións xustificarían tal cirurxía experimental

that could result in debilitating pain and neurological damage?

que podería resultar en dor debilitante e dano neurolóxico?

E cantos animais terían que morrer para demostrar que era posible?

And how many animals would have to die to prove it was possible?

At the time, bioethics was still an emerging field.

Naquela época, a bioética era aínda un campo emerxente.

Nevertheless, numerous critics, including many in the scientific community,

Con todo, numerosos críticos, incluídos moitos na comunidade científica,

recognized the cruelty of White's research and strongly opposed it.

recoñeceron a crueldade da investigación de White e opuxéronse firmemente.

Yet White continued to gain approval from agencies like the NIH.

Con todo, White continuou gañando a aprobación de axencias como o NIH.

And by 1970, he was ready to attempt a monkey body transplant.

En 1970, estaba listo para tentar un transplante de corpo de mono.

First Monkey A was installed with temporary blood vessels—

Primeiro instaláronse vasos sanguíneos temporais no mono A,

coils of plastic tubes that tethered the head to the body.

que consistían en espirais de plástico que ataban a cabeza ao corpo.

Plastic tube by plastic tube, the team connected Body B to Head A,

Tubo de plástico tras tubo de plástico, o equipo conectou o corpo B á cabeza A,

and then waited for the subject to awake from anesthesia.

e logo esperou a que o suxeito espertase da anestesia.

The monkey did— alive, paralyzed, and extremely distressed.

O mono fíxoo: vivo, paralizado e extremadamente angustiado.

According to the team, the monkey could see, smell, hear,

Segundo o equipo, o mono podía ver, cheirar, oír

and even tried to bite off one of the doctors’ fingers.

e mesmo tentou morder un dos dedos dos médicos.

White felt this proved that the operation could work.

White cría que isto era a proba de que a operación funcionaba.

The brain appeared to survive a head transplant

O cerebro parecía sobrevivir a un transplante de cabeza

and, with high doses of drugs, could live without immune rejection.

e, con altas doses de medicación, podería vivir sen rexeitamento inmunolóxico.

But had White performed a body transplant on Monkey A?

Pero realizara White un transplante de corpo no mono A?

Or was it a head transplant on Monkey B?

Ou foi un transplante de cabeza no mono B?

The surgery raises questions about the mind-body divide

A operación expón interrogantes sobre a división mente-corpo

that have been debated for millennia.

que se levan debatendo milenios.

While modern neuroscience supports the central role of the brain

Aínda que a neurociencia moderna apoia o papel central do cerebro

in building out our consciousness,

na construción da nosa conciencia,

discoveries about gut neurons and the microbiome

os achados sobre as neuronas intestinais e o microbioma

suggest that the answer may be more complicated.

suxiren que a resposta pode ser máis complicada.

Does part of the “self” reside outside of the mind?

Reside parte do eu fóra da mente?

The body and brain are interconnected by circuits and signaling systems;

O corpo e o cerebro están interconectados por circuítos e sistemas de sinalización.

so, what is lost by separating the two?

Que se perde ao separalos?

As a neurosurgeon, White performed more than 10,000 brain operations

Como neurocirurxián, White realizou máis de 10 000 operacións cerebrais

before retiring in 1998—

antes de xubilarse en 1998.

but never the human head transplant he dreamed of.

Pero nunca puido facer o transplante de cabeza humana co que soñaba.

Since then, several scientists have expressed interest in picking up

Desde entón, varios científicos expresaron o seu interese en continuar

where White left off, reviving unfinished debates.

onde White o deixou, o cal reavivou debates inacabados.

Even if a doctor could successfully connect a patient’s head

Mesmo se un médico puidese conectar a cabeza dun paciente

to a donor’s body,

ao corpo dun doante,

who of the two would emerge?

quen dos dous emerxería?

And is extending a life always worth the cost?

E merece sempre a pena alargar a vida?