How does the brain create sequences?

January 26, 2014
brain

When you learn how to play the piano, first you have to learn notes, scales and chords and only then will you be able to play a piece of music. The same principle applies to speech and to reading, where instead of scales you have to learn the alphabet and the rules of grammar.

But how do separate small elements come together to become a unique and meaningful sequence?

It has been shown that a specific area of the brain, the basal ganglia, is implicated in a mechanism called chunking, which allows the brain to efficiently organise memories and actions. Until now little was known about how this mechanism is implemented in the brain.

In an article published today in Nature Neuroscience, neuroscientist Rui Costa, and his postdoctoral fellow, Fatuel Tecuapetla, both working at the Champalimaud Neuroscience Programme (CNP) in Lisbon, Portugal, and Xin Jin, an investigator at the Salk Institute, in San Diego, reveal that neurons in the basal ganglia can signal the concatenation of individual elements into a behavioural sequence.

"We trained mice to perform gradually faster sequences of lever presses, similar to a person who is learning to play a piano piece at an increasingly fast pace." explains Rui Costa. "By recording the neural activity in the basal ganglia during this task we found neurons that seem to treat a whole sequence of actions as a single behaviour."

The basal ganglia encompass two major pathways, the direct and the indirect pathways. The authors found that although activity in these pathways was similar during the initiation of movement, it was rather different during the execution of a behavioural sequence.

"The basal ganglia and these pathways are absolutely crucial for the execution of actions. These circuits are affected in neural disorders, such as Parkinson or Huntington's disease, in which learning of is impaired", adds Xin Jin.

The work published in this article "is just the beginning of the story", says Rui Costa. The Neurobiology of Action laboratory at the CNP, a group of around 20 researchers headed by Rui Costa, will continue to study the functional organisation of the during learning and execution of action sequences.

Explore further: Switching between habitual and goal-directed actions—a 'two in one' system in our brain

More information: Basal ganglia subcircuits distinctively encode the parsing and concatenation of action sequences, DOI: 10.1038/nn.3632

Related Stories

Switching between habitual and goal-directed actions—a 'two in one' system in our brain

August 6, 2013
To unravel the circuit that underlies this capacity, the capacity to "break habits," was the goal of the study, carried out by Christina Gremel and Rui Costa, at NIAAA, National Institutes of Health, USA and the Champalimaud ...

When good habits go bad: Neuroscientist seeks roots of obsessive behavior, motion disorders

February 16, 2013
Learning, memory and habits are encoded in the strength of connections between neurons in the brain, the synapses. These connections aren't meant to be fixed, they're changeable, or plastic.

Visualizing a memory trace

July 12, 2013
In mammals, a neural pathway called the cortico-basal ganglia circuit is thought to play an important role in the choice of behaviors. However, where and how behavioral programs are written, stored and read out as a memory ...

Recommended for you

Researchers make surprising discovery about how neurons talk to each other

August 17, 2017
Researchers at the University of Pittsburgh have uncovered the mechanism by which neurons keep up with the demands of repeatedly sending signals to other neurons. The new findings, made in fruit flies and mice, challenge ...

How we recall the past: Neuroscientists discover a brain circuit dedicated to retrieving memories

August 17, 2017
When we have a new experience, the memory of that event is stored in a neural circuit that connects several parts of the hippocampus and other brain structures. Each cluster of neurons may store different aspects of the memory, ...

Researchers show how particular fear memories can be erased

August 17, 2017
Researchers at the University of California, Riverside have devised a method to selectively erase particular fear memories by weakening the connections between the nerve cells (neurons) involved in forming these memories.

Neurons involved in learning, memory preservation less stable, more flexible than once thought

August 17, 2017
The human brain has a region of cells responsible for linking sensory cues to actions and behaviors and cataloging the link as a memory. Cells that form these links have been deemed highly stable and fixed.

Study uncovers specialized mouse neurons that play a unique role in pain

August 17, 2017
Researchers from the National Institutes of Health have identified a class of sensory neurons (nerve cells that electrically send and receive messages between the body and brain) that can be activated by stimuli as precise ...

Scientists identify central neural circuit for itch sensation

August 17, 2017
Itching is an unpleasant sensation associated with the desire to scratch, and the itch sensation is an important protective mechanism for animals. However, chronic itch, often seen in patients with skin and liver diseases, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.