New Rodent Study Uncovers Distinct Neural Signals for Learning and Insights into Human Movement Disorders

Recent research conducted on lab rats has revealed that the brain's basal ganglia communicate using two separate neural coding strategies—one for newly learned movements and another for innate, natural behaviors. This discovery, published in Nature Neuroscience and led by Harvard scientists, provides new understanding of how the brain manages different types of movements. The study found that during learned tasks, the basal ganglia employ a specific set of neuronal activity patterns, while during natural behaviors like walking or grooming, they utilize a different, distinct coding language.

The basal ganglia are a crucial part of the midbrain, involved in regulating reward, emotion, and motor control. They are also linked to various movement disorders, including Parkinson’s disease, Huntington’s disease, and Tourette syndrome, all of which stem from abnormalities within this brain region.

Scientists have long debated whether the basal ganglia govern all movements or just specific learned actions. To explore this, researchers examined the dorsolateral striatum (DLS), a segment of the basal ganglia known to play a key role in learned behaviors. They trained rats to perform a lever-pressing task for rewards and observed their natural explorations. Results from prior experiments showed that removing the DLS impaired learned movements without affecting natural behaviors, suggesting a specialized role in acquired skills.

In the current study, neural activity was recorded as rats performed these behaviors. The results showed that the basal ganglia switch between active and idle states, speaking in different 'languages' depending on the behavior—an essential step toward understanding motor control mechanisms. The findings suggest that the basal ganglia are central in learning new movements but may not directly control routine, natural behaviors.

These insights have significant implications for understanding human movement disorders. For instance, in Parkinson’s disease, the basal ganglia may produce erratic signals, effectively speaking a 'gibberish' language that interferes with normal movement. Understanding these neural codes could lead to novel approaches for treating such diseases.

Overall, this study advances our knowledge of how the brain manages learned versus innate movements and highlights the critical role of the basal ganglia in motor learning and disorders.

Source: https://medicalxpress.com/news/2025-08-rodent-reveals-codes-skills-clues.html