Passing Infection Removes Mice's Feline Fear Forever
传递感染会让老鼠永远丧失对猫的恐惧
A bad infection can make you delirious. But usually the mind clears once the germs are gone. Usually.
严重的感染会导致你神志不清。但是通常病菌消失之后你就会变得清醒。通常是。
Not so when researchers recently injected mice with Toxoplasma gondii. This parasitic protozoan only gets amorous inside the gut of a cat. The resulting fertilized eggs wind up in a litter box. Their challenge is to grow up and get back inside a feline. The solution: get eaten by a mouse that gets eaten by a cat.
研究人员最近给小白鼠注射弓形虫却没符合惯例。这种寄生虫只在猫的肠道里繁殖。由此产生的受精卵散入垃圾箱内。它们的挑战是长大重新回到猫体内。解决方案是被被猫吃掉的老鼠吃掉。
The expelled eggs wait until they become a meal for a mouse. The parasites then move to the mouse’s brain. Where they stop the rodent from fearing the smell of cat urine. The delirious mouse approaches Fluffy and, voila, the parasite finds its way home.
幼卵等待变成老鼠的一餐。然后进入老鼠的大脑。它们使老鼠丧失对猫尿气味的恐惧。神志不清的老鼠接近猫,就这样,寄生虫找到了回家的路。
In past trials, mice almost always died of this kind of infection. This study used weaker strains of Toxo and the mice recovered—but they stayed blasé about the cat smell.
过去的实验中,老鼠几乎总是死于这样的感染。这次的研究用了较弱的病毒,老鼠恢复了,但是它们还是不害怕猫的气味。
That a curable infection can cause permanent behavior changes is worrisome because this same parasite infects 60 million people in the U.S. alone. Most cases produce no symptoms. But some evidence links chronic infection to schizophrenia and a cluster of other mental illnesses—known unscientifically as “crazy cat lady syndrome."
可治愈的感染 引起永久性的行为改变是令人担忧的,因为同样的寄生虫感染单单在美国每年会感染6000万人。大多数情况下不会产生症状。但是一些证据证明慢性感染跟精神分裂症和其他精神疾病,俗称为疯狂猫夫人综合症,有关。
—Wayt Gibbs