Photo caption: At the point of giving up, neurons in green get very active and suppress dopamine, a chemical associated with motivation, researchers found. Credit: Max Hunter
Researchers at the University of Washington Health Sciences (UW Medicine) have published a paper offering new insight into the science of motivation.
For four years a team of researchers focused on nociceptin, a complex molecule that suppresses dopamine, a chemical associated with motivation.
When a mouse is about to reach its ‘breaking point,’ nociceptin neurons activate and emit nociceptin, according to the paper. While scientists have previously studied the effects of simple neurotransmitters on dopamine neurons, this is one of the first studies to analyze the effects of nociception, a complex neurotransmitter, on the modulatory system.
“We might think of different scenarios where people aren’t motivated like depression and block these neurons and receptors to help them feel better,” said senior author Michael Bruchas, professor of anesthesiology and pain medicine and of pharmacology at the University of Washington School of Medicine is one of the principal faculty in UW’s new Center for Neurobiology of Addiction, Pain, and Emotion.
“That’s what’s powerful about discovering these cells. Neuropsychiatric diseases that impact motivation could be improved.”
For their study, researchers observed mice who had to poke their nose through an opening to get a treat.
After getting a treat on the first try, scientists then increased their attempts to two pokes, then five, increasing exponentially.
All the mice eventually gave up.
Neural activity recordings revealed that “de-motivation” or “frustration” neurons became most active when mice stopped trying to get a treat.
“In the wild, animals are less motivated to seek rewards in environments where resources are scarce,” the study’s authors said in a statement.
“Persistence in seeking uncertain rewards can be disadvantageous due to risky exposure to predators or from energy expenditure … deficits within these regulatory processes in humans can manifest as behavioral dysfunctions, including depression, addiction, and eating disorders.”
The findings have been published in the journal Cell.
Read more about the study here.