Single Gene Turns Subservient Mouse into Boss Mouse
mice meet in a narrow plastic tube that’s not wide enough for both of them.
That sounds like the opening of a really bad science joke, but stick with
me. The punchline is downright amazing:
One of them must give way. In their earlier encounter, the first
mouse exerted its dominance by forcing its rival to reverse down the
tube. This time, things are different; the second mouse pulls rank and
the first one backs down.
Mouse hierarchies don’t change this readily, but the second mouse
has been given a boon by Fei Wang at the Chinese Academy of Science.
By injecting a single gene into one part of its brain, Wang turned the
subordinate animal into a dominant one.
The gene that gave the mouse a burst of social mobility is GluR4.
It creates part of a protein called the AMPA receptor, which allows
signals to flow quickly between two neurons. By injecting extra GluR4
into a mouse’s brain, and producing more AMPA receptors, Wang
strengthened the connections between its neurons. The effect is like
building expressways between two cities overnight – you can have
a much larger and faster flow of traffic between them. [...]
By manipulating this signalling, he could push mice up or down
the social ladder. With an extra dose of GluR4, the mice gained social
standing. When they confronted other mice in a cramped plastic tube,
they were more likely to force their rivals to retreat, even if they
had previously given way. With their new rank, they were also more likely
to court female mice with high-pitched ultrasonic songs.