Science News - August 11, 2012

Lifting neural constraints could turn back
time, making way for youthful flexibility

By Laura Sanders Ababy’s brain is a thirsty sponge, slurping up words, figuring out faces and learn- ing which foods are good and bad to eat. Information about the world flooding into a young brain begins to carve out traces, like rushing water over soft limestone. As the outside world sculpts the growing brain, important connections bet ween nerve cells become strong rivers, while smaller unused tributaries quietly disappear.

Prying at windows

Research aimed at restoring the brain’s
youthful flexibility is leading to a more
nuanced view of findings from the
1960s. In experiments that won them
the Nobel Prize in physiology or medi-
cine, David Hubel and Torsten Wiesel
discovered that sealing shut a kitten’s
eye for a period during the early stage
of life would leave the animal unable to
see normally out of that eye. If the oppo-
site eye were then patched, forcing the
underdeveloped eye to work, the kitten
could recover, scientists later discov-
ered. This patch fix worked only on a
young animal, suggesting there was a
finite window of time during which the
brain could rewire itself.

Birth– 5 years

Periods with potential Different functions in the brain, such as thinking and seeing, develop during varying time windows, as nerve cells form new connections called synapses. Though scientists used to think such development had clear peaks and then waned with age (shown), evidence now suggests substantial ;exibility can be restored in adulthood.