Dopamine neurons, the cells that drive reward and motivation while we’re awake, become surprisingly active during nonrapid eye movement sleep right after we learn something new.
According to a new University of Michigan study, this night surge that is synchronised with memory-boosting sleep spindles, helps strengthen motor memories and improves motor skills.
The findings challenge long-held assumptions about dopamine’s role in the brain, showing that these neurons don’t just support learning during the day – they actively help lock in new skills while we sleep, said study co-author Ada Eban-Rothschild, U-M associate professor of psychology.
“As alterations in dopamine signalling are associated with neurodegenerative diseases that also involve motor deficits and sleep disturbances, understanding these links could pave the way for improved therapeutics and advancements in human health,” she said.
The study focused on specific midbrain dopamine neurons that become active after learning, but only during nonrapid eye movement, or NREM, sleep. This burst of activity helps the brain fine-tune and reinforce newly learned movements, contributing to more precise motor performance once awake.
Understanding how dopamine supports motor learning at night also sheds light on the broader importance of sleep in shaping behavior, said Eban-Rothschild and colleagues.
“The findings highlight that sleep is an active biological period during which key neural circuits strengthen the skills and patterns we rely on every day,” she said.
By revealing how dopamine helps consolidate motor memories during sleep, the researchers say the findings open a new window into brain health: It may eventually guide the development of therapies that target both sleep and dopamine pathways, offering new hope for improving motor function and quality of life in affected individuals.
The study was published in the Journal Science Advances. In addition to Eban-Rothschild, the study’s authors are Bibi Alika Sulaman, Eric Chen, Aaron Crane, Sangjin Lee and Gideon Rothschild
Source: University of Michigan
