‘Flip switch’ creates instant binge eaters
Mouse brains might point the way to unravelling the cause of eating disorders. ANDREW MASTERSON reports.
Binge-eating might be prompted by a neurological “flip switch”, suggests new research based on experiments that prompted mice to eat more than a third of their daily food intake in just 10 minutes.
The mice pig-out was caused by stimulating a little-studied area of the brain for just a few seconds.
Xiaobing Zhang and Anthony van den Pol, of the Yale School of Medicine in Connecticut, discovered the effect while researching the zona incerta (ZI), an elongated section of grey matter located in the brain’s subthalamus region.
Stimulating the ZI for just a few seconds produced immediate bingeeating behaviour in the rodents. Repeated stimulation – for five minutes every three hours over two weeks – led to greatly increased food intake and weight gain.
Further experiments revealed the ZI cells also became stimulated when food was withheld from the mice, catalysing the release of ghrelin, called the “hunger hormone” and known to stimulate appetite.
When the periods of artificial stimulation came to an end, the researchers also noted that food intake rapidly dropped to a level below that of the untreated mice used as controls. The study, published in the journal Science, might provide insight into binge-
“STIMULATING THE ZI FOR JUST A COUPLE OF SECONDS PRODUCED IMMEDIATE BINGE- EATING BEHAVIOUR IN THE RODENTS.”
eating in humans, the mechanics of which remains little understood.
Zhang and van der Pol suggest that ZI activation might play a role. They note that when some types of movement disorder are treated using deep brain stimulation of the subthalamus – and hence also the ZI – binge-eating behaviour is often an unwelcome side-effect.