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Skilled motor movements like pianists playing a concerto require precise interactions between the motor cortex - the region of the cerebral cortex involved in the planning, control, and execution of voluntary movements - and the rest of the brain. 

"Every time you wanted to hear a specific note, there was a specific key to press," said Andrew Peters, a neurobiologist at UC San Diego's Center for Neural Circuits and Behavior, in the press release. "In other words, every specific movement of a muscle required the activation of specific cells in the motor cortex because the main job of the motor cortex was thought to be to listen to the rest of the cortex and press the keys it's directed to press."

However, in a new study published recently, researchers discovered that motor cortex itself plays an active role in learning new motor movements. 

"Our finding that the relationship between body movements and the activity of the part of the cortex closest to the muscles is profoundly plastic and shaped by learning provides a better picture of this process," said Takaki Komiyama, an assistant professor of biology at UC San Diego who headed the research team, in the press release. "That's important, because elucidating brain plasticity during learning could lead to new avenues for treating learning and movement disorders, including Parkinson's disease."

Researchers experimented on mice to show in details how those movements were learned over time. They monitored the activity of neurons in the motor cortex over a period of two weeks while mice learned to press a lever in a specific way with their front limbs.

"What we saw was that during learning, different patterns of activity-which cells are active, when they're active-were evident in the motor cortex," added Peters. "This ends up translating to different patterns of activity even for similar movements. Once the animal has learned the movement, similar movements are then accompanied by consistent activity. This consistent activity moreover is totally new to the animal: it wasn't used early in learning even with movements that were similar to the later movement."

The study is published in the advance online publication of the journal Nature.