VOA慢速英语--科学家成功复活死猪脑部细胞

Scientists Restore Some Activity in Brains from Dead Pigs

Scientists say that the brains of animals and humans risk severe damage without blood flow and oxygen. But, researchers say they were able to restore some activity in the brains of pigs that had been killed four hours earlier.

Nenad Sestan of the Yale School of Medicine in New Haven¹, Connecticut was one of the researchers. He said, by medical definitions, the brains were not “living brain(s).” He added that the brains could not think or sense anything.

The researchers, however, found that cells within brains that have lost their supply of blood and oxygen could survive longer than scientists had believed.

They said the research might lead to new medical treatments for stroke and other conditions. It also provides a new way to study the brain and how drugs work in it.

The research was supported mostly by the National Institutes of Health and published this week in the journal Nature.

The 32 brains in the study came from pigs that had been killed for food. The scientists put the brains into a device in their lab. Four hours after the animals died, they began pumping a specially² designed blood substitute through the organs.

After six hours, scientists found that individual brain cells in one area of the brain had continued to keep important details of their structure. And when they sent electric signals to the brains, the cells responded in a way that showed viability³.

The scientists studied the artificial blood before and after it entered the treated brains. They found the brain cells were absorbing blood sugar and oxygen and producing carbon dioxide: a signal that they were working. They also found that blood pathways in treated brains reacted to a drug that makes them wider.

But, the brains did not show large amounts of activity that would be a sign of consciousness⁴. The scientists said restoring consciousness was not the goal of the study. And they do not know whether it is possible.

The scientists said they had no plans to try their methods on human brains at this time. However, they are now looking to keep the study for longer than six hours of treatment.

Christof Koch is president of the Allen Institute for Brain Science in Seattle, Washington. He did not take part in the study, but he said he was surprised by the results, especially since they came from such a large animal.

He said the study could increase our knowledge “to bring people back to the land of the living” after a drug overdose. He suggested it also could help with treatments for when the brain has not received enough oxygen for an hour or two.

Koch said the results of the study also raised questions about the widely used definition of death – the irreversible loss of brain activity.

I’m Jonathan Evans.

Words in This Story

restore –v. to return something to its earlier condition

viability –n. able to live or develop into a living thing

artificial –adj. not natural, made by people

absorb –v. to take in something such as a liquid

consciousness –n. the state of being awake and aware

1 haven   

n.安全的地方，避难所，庇护所

参考例句：

• It's a real haven at the end of a busy working day.忙碌了一整天后，这真是一个安乐窝。
• The school library is a little haven of peace and quiet.学校的图书馆是一个和平且安静的小避风港。

2 specially   

adv.特定地；特殊地；明确地

参考例句：

• They are specially packaged so that they stack easily.它们经过特别包装以便于堆放。
• The machine was designed specially for demolishing old buildings.这种机器是专为拆毁旧楼房而设计的。

3 viability   

n.存活(能力)

参考例句：

• What is required to achieve or maintain such viability? 要达到或维持这种生存能力需要什么？
• Scientists are experimenting to find ways to ensure the viability of seeds for even longer periods of time. 正如我们所说，科学家正在试验努力寻找让种子的生命力更加延长的方法。

4 consciousness   

n.意识，觉悟，知觉

参考例句：

• The experience helped to change her social consciousness.这种经验有助于改变她的社会意识。
• He lost consciousness at the first whiff of ether.他一嗅到乙醚便失去了知觉。