快猫短视频

BY PERFORMING some unusual brain surgery, researchers have created a chicken
鈥渃himera鈥� that prefers the maternal cries of quails to the calling of mother
hens. The work may help us understand how our brains evolved to perceive and
react to the world.

Evan Balaban and his colleagues at The City University of New York found they
could change how chickens respond to their mother鈥檚 voice by replacing a sliver
of tissue between the mid and forebrain with a slice from a Japanese quail. This
region lies outside known sound-processing areas of the brain, and its exact
role is a mystery.

鈥淭hat you can transplant it in a bit of discrete tissue is really amazing,鈥�
says Mark Konishi, a behavioural neurobiologist at the California Institute of
Technology in Pasadena. 鈥淚t makes me wonder, where does it stop? What other
brain activity can be programmed into a bit of tissue?鈥� He says the response to
maternal voice was thought to be a complex behaviour distributed throughout the
brain.

Balaban鈥檚 team operated on 16 two-day-old chicken embryos. They sliced out
segments of the developing nervous system鈥攁 thin tube of tissue 70
millimetres long鈥攁nd replaced it with the same section from a quail
embryo. When the chicks hatched the team tested their response to computerised
clucking from the two species. Nine of the birds preferred their own kind. But
seven who received sections of the midbrain not only favoured the virtual quail
mother, they showed a stronger preference than most normal quails. Balaban鈥檚
team has already used the same transplant technique to make chickens sing like
quails (快猫短视频, 15 March 1997, p 16).