Study: Learning Changes the Brain

W A S H I N G T O N, Oct. 19 -- Researchers said todaythey had shown for the first time how learning makes physicalchanges in the brain.

Rats trained to do a simple task — using one paw to dig afood pellet out of a box — had permanent brain changes thatcould be measured with electrical currents, the team at BrownUniversity in Rhode Island said.

“It’s a simple experiment, it’s a simple idea and itworked,” neuroscientist Mengia-Seraina Rioult-Pedotti, who ledthe study, said in a telephone interview.

Brain Slices Showed Activity

“I put the animal in a box and in this box is a small boxwith a hole. And the animal had to learn how to reach into thehole with the right forepaw. I trained them for five days …and they got better every day,” said Pedotti, who reported herfindings in this week’s issue of the journal Science.

“After five days I removed their brains, I cut slices, andI recorded responses.”

She ran electrical currents through the still-living slicesof brain tissue and found definite differences in regions knownto control the activity of the rats’ right front paws.

Just as in humans, the left side of a rat’s brain, ingeneral, controls the right side of its body and vice-versa.Pedotti’s team looked for changes in the left motor cortex.

“I measured activity in the area that is specific for theforelimb in the cortex,” she said. “The animals learned with asingle forelimb and the changes in the brain occurred in onlyone hemisphere.”

She could check the animals’ other hemisphere as a controland found that the synapses — the connections between neurons — were stronger in the region that controlled the new task.

Translated Into Visible Changes

“The animal is learning, I can see a change in behavior,and I can see a change in the brain,” Pedotti said.

Pedotti also wanted to prove a theory that a process calledlong-term potentiation (LTP) is responsible for strengtheningthese connections.