In a paper in the December 19 issue of Nature, neurobiologist Karel Svoboda and his research team present the most convincing proof to date that the adult brain can rewire itself in response to outside world. While many neuroscientists had begun to speculate that adult brains might be more dynamic than once thought, neuroscience orthodoxy still held that adult brains are relatively stable, limiting learning and recovery from injury. Svoboda's team employed state of the art technology to show that new connections, called synapses, form and dissolve in the adult brain as the mice take in sensory information.
"If a few years ago you could have imagined in your wildest dreams the experiment you wanted to do, it would be this one," said Paul Adams a neurobiologist at the State University of New York, Stony Brook. "To show that, in a relatively short period of time, synapses grow in an adult brain."
The scientists created transgenic mice with neurons that expressed a fluorescent green protein. Then, they placed a small window over the part of the brain they wanted to study--the barrel cortex, a region associated with receiving information the mice gather with their whiskers. Every 24 hours for eight days and less frequently for the rest of a month, they checked to see which neurons sent out and retracted spines to form and eliminate connections with other neurons. To see if the changing connections were influenced by sensory input they cut every other whisker on the mice, creating a chessboard pattern in which each cut whisker was surrounded by uncu
Contact: Peter Sherwood
Cold Spring Harbor Laboratory