Modified mouse stands up to cat

Cat and mouse may never be the same.

Japanese scientists say they have genetically engineered mice that show no fear of felines, a development that may shed new light on mammal behavior and the nature of fear itself.

Scientists at Tokyo University say they succeeded in switching off a mouse’s instinct to cower at the smell or presence of cats -- showing that fear is genetic and not learned through experience.

“Mice are naturally terrified of cats and usually panic or flee at the smell of one. But mice with certain nasal cells removed through genetic engineering didn’t display any fear,” said research leader Ko Kobayakawa.

In the experiment, the genetically altered mice approached cats, even snuggled up to them and played with them. Kobayakawa said he chose domesticated cats that were docile and thus less likely to pounce.

Kim Dae-soo, a neural genetics professor at the Korea Advanced Institute of Science and Technology in Seoul, who was not involved in the study, said Kobayakawa’s research could explain further what fear is and how to control it: “If we follow the pathway of related signals in the brain, I think we could discover what kind of networks in the brain are important for controlling fear.”