Scientists Turn Mild-Mannered Mice IntoKillers  (科学家找到开关：老鼠一秒变狂暴杀手)

Step aside killer zombies: scientists havedelved deep into ancient brain circuits to reveal neurons that can turnmild-mannered mice into ferocious predators-before switching the rodents backto their normal placid selves.

The researchers at Yale University used “optogenetic”technology, which switches specificneurons on and off in genetically engineered animals using laser light, to tapinto brain mechanisms that control predatory hunting.

“We’d turn the laser on and they’d jump on an object, hold it with their paws and intensively bite it as if they were trying to capture and kill it,”said Ivan de Araujo,lead investigator.

The mice attacked not only live prey suchas crickets, which they immediately devoured, but also inanimate objects suchas mobile plastic toys that they would normally avoid.

The study, published in the journal Cell,was part of a broader programme to research feeding behavious in animals. Theinvestigation of various brain regions showed that the central nucleus of theamygdala was closely associated with the urge to hunt and with controlling thejaw and neck muscles required to subdue and kill prey.

By manipulating brain cells in this regionthrough optogenetics, the Yale team found one distinct set of neuronscontrolled pursuit and another controlled pursuit and another controlled thekill. If the hunting neurons were switched on and the biting set inactivated,the mice pursued prey but could not deliver the killer bite to finish it off.

The next stage in the Yale project will be to explore how sensory inputs-form the eyes, nose and ears-into the amygdala trigger predatory behaviour and co-ordinate its pursuit and killing modules. “We now have a grip on their anatomical identities, so we hope we can manipulate them even more precisely in the future, ”said Prof de Araujo.

The brain mechanisms involved are ancient. He said the ability to bunt was a “major evolutionary advantage”, pointing to the evolution of jaws invertebrates, which began with fish about 400m years ago.

The Yale research could have practical applications,such as treating neurological diseases. Researchers in mobile robotics and artificialintelligence could also use information from the predatory brain to create a devicethat pounces on a moving target, Prof de Araujo added.

But the production of killer zombie mice isnot on the agenda.

词汇总结

Predator     n.捕食者；食肉动物；掠夺者

Step aside killer zombies: scientists havedelved deep into ancient brain-circuits to reveal neurons that can turnmild-mannered mice into ferocious predators.

Laser     n.激光

We’d turn the laser on and they’d jump onan object, hold it with their paws and intensively bite it as if they were tryingto capture and kill it.

Devour     v.贪婪地、狼吞虎咽地吃，吃光；（猛兽等）吞食，吞光

The mice attacked not only live prey such ascrickets, which they immediately devoured.

Vertebrates     n.脊椎动物

He said the ability to hunt was a “major evolutionaryadvantage”, pointing to the evolutionary advantage”, pointing to the evolutionof jaws in vertebrates, which began with fish about 400m years ago.

Pounce on      猛扑向；突然袭击

Researchers in mobile robotics andartificial intelligence could also use information from the predatory brain to createa device that pounces on a moving target.