How the Brain Learns

Scientists have long held that learning and memory formation are
made possible by the strengthening and weakening of connections among
brain cells, but until recently scientists didn't know how the process
worked.

Using brain cells from mice, Johns Hopkins University researchers
have discovered the key molecule necessary for certain cells to weaken
their connections with others. When scientists replaced the molecule -- a
protein called GluR2 -- with a modified form, they found the weakening
process halted.

Lead researchers Richard Huganir and David Linden, both professors
of neuroscience, hope to create a mouse that has only the modified form
of GluR2 and test its motor learning abilities. Any deficiencies in the
mouse's learning skills will serve as proof that the weakening of
connections among cells plays an important role in the learning
process.

"It's about as close as we've gotten to understanding a behavior at
a molecular level," says Huganir.

The findings were published in the journal
Science.