Brain chemical linked to breaking bad habits identified in study
7 reported
Scientists at the Okinawa Institute of Science and Technology (OIST) have identified a brain chemical that appears to help animals break old habits and adapt when circumstances change, according to a study published in Nature Communications. Researchers trained mice to navigate a virtual maze for a reward, then changed the rules so the reward was no longer delivered. Using two-photon microscopy, the team observed a surge of the neurotransmitter acetylcholine in the animals’ brains when the expected reward failed to appear. Mice that showed a greater increase in acetylcholine were more likely to change their choices in the maze, a behavior the researchers called “lose-shift.” When the animals’ ability to produce acetylcholine was reduced, they showed less flexibility and were more likely to stick with outdated strategies. The researchers noted that not all groups of cholinergic interneurons reacted the same way, with some showing little change or a decrease in activity, which may help preserve information about previously successful behaviors. The study’s authors said the findings could improve understanding of conditions that make it difficult to break habits, including addiction, obsessive compulsive disorder, and Parkinson’s disease.
What’s reported
The study was published in Nature Communications by researchers at the Okinawa Institute of Science and Technology (OIST).
Mice were trained to navigate a virtual maze for a reward, then the reward pathway was switched.
A surge of the neurotransmitter acetylcholine was observed when the expected reward did not appear.
Mice with higher acetylcholine increases were more likely to display “lose-shift” behavior and change their choices.
Reducing acetylcholine production made mice less likely to adjust their decisions after an unexpected outcome.
Some clusters of cholinergic interneurons showed little change or a decrease in activity, which researchers said may help retain information about previously successful behaviors.
The researchers said the findings may eventually contribute to better treatments for addiction, OCD, and Parkinson’s disease.
Key figures
Professor Jeffery Wickens, co-author and head of the Neurobiology Research Unit at OIST
Dr. Gideon Sarpong, first author on the study
Sources: ScienceDaily
