A brain chemical tells when to fight or flee

Nitric oxide turns off urge to fight, making battered crickets flee a face-off

BRAWL OR BOLT A Mediterranean field cricket depends on its nerve cells to release nitric oxide to help it decide when it’s beat in a fight and needs to flee.

Paul A. Stevenson, Jan Rillich

By Kate Baggaley

March 13, 2015 at 2:00 pm

When it comes to fight or flight for brawling crickets, a chemical in the brain is in charge. Being roughed up in a skirmish can trigger nerve cells in Mediterranean field crickets (Gryllus bimaculatus) to release nitric oxide, making the losing cricket run away, scientists report online March 13 in Science Advances.

Watch in this video as two crickets face off. When the loser hits its limit, it flees the fight. In a second bout, the loser then tries to avoid the winner. Nitric oxide prompts this continued submissive behavior, which lasts several hours before a cricket’s will to fight returns.

“If you block nitric oxide they recover quickly, and if you give them nitric oxide they don’t,” says Paul Stevenson, a coauthor of the new research and behavioral neurobiologist at Leipzig University in Germany. “It’s a very simple algorithm for controlling a very complicated social situation.”