Flexible brain circuits can switch between different tasks

In everyday life, the brain juggles a wide variety of cognitive tasks. Scientists have theorized that the brain contains clusters of neurons, modules, that perform the same computations across different types of tasks. This modularity aids in explaining the brain's ability to handle many functions with ease. MIT neuroscientists have discovered the first evidence of flexible brain modules in mice.

They identified neurons in the prefrontal cortex that can store either sensory input or action plans in working memory. Dr. Yuma Osako, lead author of the study, stated, "The brain doesn’t dedicate a separate group of neurons for every type of information. Instead, it uses the same populations of neurons to perform the same computation on different kinds of information."

This discovery supports the theory that reusable circuits facilitate the brain's ability to mix and match components to generate a wide range of behaviors. Dr. Mriganka Sur and Dr. Timothy Buschman are the senior authors of the paper published in Nature Neuroscience. Dr. Buschman, from the Princeton Neuroscience Institute, has long been intrigued by the brain's ability to perform various behaviors.

His lab demonstrated last year that neural circuits can be flexibly assembled to perform different pieces of a task, like "cognitive Legos." Osako and Sur, along with Dr. Buschman, explored whether individual neural circuits can be repurposed for different functions. They trained mice on a task requiring them to differentiate between two sensory stimuli and respond accordingly.

By recording the mice's brain activity, they discovered that a cluster of neurons in the prefrontal cortex could switch between storing sensory input and action plans in working memory. This flexibility allows the brain to store and manipulate different types of information, enabling the animals to handle a variety of tasks with ease.