ANN ARBOR—Stimulating the brain’s circuitry related to addiction can create strong desires even for something that hurts.

A new University of Michigan study published in Nature Communications used a laser to excite neurons in the amygdala—a brain region that generates emotional responses—to create intense desires focused on particular targets.

These targets, for different rats, were either sugar, cocaine or even an object painful to touch, each paired with brief amygdala excitation. The addictive-type desire was equally strong, whether the target was liked or disliked, the researchers found.

In each desire group, the amygdala recruited additional addiction-related brain circuitry to create a strong and narrowly focused wanting for its paired target, whether the target itself was pleasant or painful,” said Kent Berridge, U-M professor of psychology.

The findings reveal how brain circuitry can create addictive-like maladaptive desires for particular targets, even in the absence of any pleasure. The results also help reveal how emotional brain systems can, in certain circumstances, flexibly switch between generating opposite motivations of desire and fear, said Shelley Warlow, a postdoctoral fellow at the University of California at San Diego and the study’s lead author.

Erin Naffziger, a U-M psychology doctoral student, also co-authored the study.

Read the full article at Michigan News.