Neuroscientists Discover How Brain Circuits Reorganize During Learning of New Movements

Recent research conducted by scientists at the University of California San Diego has shed new light on the neurological basis of motor learning. Published in the journal Nature, the study uncovers how brain circuits are physically and functionally reshaped as animals learn new movements, paving the way for advancements in therapies and technologies for neurological conditions.

For decades, the primary motor cortex (M1), located in the frontal lobe, was considered the key region responsible for initiating complex motor actions during learning. Recently, focus expanded to include the motor thalamus—an area situated deep within the brain—which influences M1 activity during skill acquisition.

Despite these insights, understanding the precise mechanisms of how learning unfolds at the cellular level remained elusive, primarily due to the difficulty in monitoring interactions across multiple brain regions simultaneously. To overcome this, a team led by Professor Takaki Komiyama utilized cutting-edge neurobiological tools, including high-resolution imaging and innovative data analysis techniques, to explore these dynamics in mice.

Their groundbreaking findings identified the thalamocortical pathway—a communication route between the thalamus and the cortex—as a central player in learning-associated brain plasticity. The study revealed that as animals learned specific movements, the neural connections between these regions physically changed, reinforcing the fact that motor learning involves more than just altering activity levels; it involves reshaping the neural circuitry itself.

"Our results demonstrate that learning refines the communication pathways within the brain, making them more efficient and precise," explained Assaf Ramot, the study’s lead author. "It's not merely about what the brain does — it's about how the wiring of the brain changes to support new skills."

During the learning process, the thalamus activates particular subsets of neurons in the motor cortex to encode the new movement, while suppressing unrelated neural activity. This targeted reorganization ensures a focused and efficient learning process. The researchers also developed a novel analytical method named ShaReD (Shared Representation Discovery), enabling them to identify behavioral neural patterns common across different subjects.

Developed alongside neurobiology expert Marcus Benna and graduate student Felix Taschbach, ShaReD was crucial for interpreting complex neural data and overcoming the variability in behavior and neural responses between animals. Unlike traditional methods that impose artificial alignment, ShaReD identifies consistent behavioral representations, facilitating cross-subject comparisons.

This study builds on prior work by the same lab that explored synaptic rules during learning and contributes to a comprehensive model of how neural circuits underlying movement are formed and modified. The findings underscore that brain reorganization is targeted and specific, which has significant implications for developing targeted neurorehabilitation therapies.

"Understanding these mechanisms opens new avenues for designing interventions for stroke recovery, neuroprosthetic development, and brain-computer interfaces," stated Ramot. "By deciphering how brain circuits rewire themselves during learning, we can better mimic or facilitate these processes in clinical applications."

Additionally, this research is dedicated to the memory of An Wu, a talented scientist whose contributions helped advance understanding of neural mechanisms, and who tragically passed away in 2023.

For more details, see the original study: Motor learning refines thalamic influence on the motor cortex, Nature (2025). DOI: 10.1038/s41586-025-08962-8.

Source: https://medicalxpress.com/news/2025-05-neuroscientists-brain-circuits-reshaped-movements.html