Chocoholic mice fear no pain

Ever get a buzz from eating chocolate? A study published in the open access journal BMC Neuroscience has shown that chocolate-craving mice are ready to tolerate electric shocks to get their fix.

Rossella Ventura worked with a team of researchers from the Santa Lucia Foundation, Rome, Italy, to study the links between stress and compulsive food-seeking. She said, “We used a new model of compulsive behavior to test whether a previous stressful experience of hunger might override a conditioned response to avoid a certain kind of food - in this case, chocolate”.

Ventura and her colleagues first trained well-fed mice and starved mice to seek chocolate in one chamber rather than going into an empty chamber. Then, they added a mild electric shock to the chamber containing the chocolate. Unsurprisingly, the well-fed animals avoided the sweet treat. 

However, mice that had previously been starved, before being allowed to eat their way back up their normal weight, resisted this conditioning - continuing to seek out chocolate despite the painful consequences. This is an index of compulsive behavior and the researchers claim that this matches compulsive food seeking in the face of negative consequences in humans.