The Mojo Hand, or winning boys luck, is an old Voodoo ritual. It’s basically
a magical charm bag intended to give the holder “Mojo”, or winning boys luck.
Now, Chinese scientists may have cracked the code to winning in a recent
experience by stimulating the pre-frontal cortex of mice and giving them the
Chinese researchers may have revealed the secret of why animals increase their
probability of victory after previous winnings, a phenomenon known as the “winner
In a study published Thursday in the US journal, Professor Hailan Hu’s research
group from Zhejiang University in China reported identifying for the first time a
neural circuit in the brains of mice that plays a role in social dominance.
Stimulating brain cells in this circuit, known as dorsalmedial prefrontal cortex
(dmPFC), significantly boosted a mouse’s chance of becoming the “winner” during
aggressive encounters with other mice.
“Getting to the top of social hierarchy is often not a matter of body size or brute
strength, but rather determined by intrinsic mental factors such as grit, as well as
extrinsic factors such as history of winning. For example, social dominance can be
reinforced by a phenomenon known as the ‘winner effect,'” Hu said. “However, the
neural mechanism that mediates these intrinsic and extrinsic factors was poorly
For the study, Hu’s team performed a standard social dominance test that put male
mice in a tube to face each other. Usually the subordinate animal would retreat and
back out of the tube.
Then, the researchers recorded how much each one engages in certain behaviors such
as push initiation, push-back, resistance, retreat, or stillness. By monitoring
individual brain cells in the dmPFC during such tests, they found a particular subset
became more active during both push and resistance behaviors.
In mice with an established social rank, the researchers inhibited this subset of
dominance brain cells using a drug and found within hours, these mice engaged in
significantly fewer and shorter pushes and push-backs, but in more retreats.
Next the researchers used optogenetics to stimulate the dmPFC cells continuously
during a social dominance encounter.
This instantaneously induced winning against previously dominant opponents with a
90 percent success rate, without affecting the motor performance or anxiety level.
“Importantly, dmPFC activation does not seem to boost dominance by enhancing basal
aggression level or physical strength, but rather by initiating and maintaining more
effortful behaviors during social competition,” Hu said.
The findings could have important implications for treating psychiatric diseases,
the researchers said.
“Considering that an excess or lack of dominance drive is associated with many
personality disorders and mental problems, our results might shed light on the
treatment of these psychiatric diseases,” the study said.