Researchers find evidence of brain rewiring thru active learning

Researchers at University of California, Berkeley, have found evidence supportive of "active learning," an approach that promotes critical thinking and problem-solving in schools and workplaces.

In laboratory tests, the researchers tapped into the minds of mice with advanced microscopy techniques and captured unique images of problem-solving in action, showing rapid rewiring in the rodents' frontal brains after they learn by trial and error.

In a study published in the latest issue of the journal Nature Communications, the researchers led by Linda Wilbrecht, an associate professor of psychology and neuroscience at UC Berkeley, described that when mice used new strategies to find hidden treats during a foraging task, they showed a dramatic resculpting of their frontal lobes.

"We are excited because these are the first pictures of live rewiring in the brain at the synaptic level that capture a trace of this higher-order form of learning," said Wilbrecht.

The researchers tracked daily changes in the synapses of the orbital frontal cortices of mice as they learned new rules. They did so by having mice explore various strategies to find Cheerios, a breakfast cereal, that were hidden in bowls of wood shavings scented with either licorice, clove, thyme or fruit. The rules for how to find the Cheerios changed on a daily basis.

For example, on the first day of the experiment, the mice learned that the scent of licorice would lead them to a Cheerio hidden at the bottom of a bowl, but they received no other clues.

"They had to discover the rule that led them to a Cheerio using trial and error," Wilbrecht said.

Mice carried out the foraging task in the morning, and brain changes were recorded in the afternoon. Using a technology known as 2-photon laser scanning microscopy, the researchers took pictures of the growth and pruning in the brain circuitry of long-range axons, conduits for electrical signals that connect neurons in the frontal lobe's executive centers.

The mice who puzzled out the new rules on a daily basis showed dramatic changes in the wiring that broadcasts information from the orbitofrontal cortex. "Importantly, these changes scaled with each animal's trial-and-error strategy and experience, suggesting they reflect each animal's intellectual growth," Wilbrecht said.

By contrast, mice who received Cheerios freely without having to navigate rules showed no uptick in brain circuit remodeling.

While similar time-lapse movies have documented brain restructuring during motor, sensory and fear-conditioning tasks, Wilbrecht said, "visual evidence has been lacking for the more complex, cognitive, strategy-based trial-and-error learning that helps us grow each day at school and at work."

The new data, she said, "push us towards greater recognition of how multiple dimensions of learning, particularly active learning, may be sculpting our brains." Endit