For most of its 100-year history, neuroscience has embraced a central dogma: a mature adult's brain remains a stable, unchanging, computerlike machine with fixed memory and processing power. You can lose brain cells, the story has gone, but you certainly cannot gain new ones. How could it be otherwise? If the brain were capable of structural change, how could we remember anything? For that matter, how could we maintain a constant self-identity?
Although the skin, liver, heart, kidneys, lungs and blood can all generate new cells to replace damaged ones, at least to a limited extent, until recently scientists thought that such regenerative capacity did not extend to the central nervous system, which consists of the brain and spinal cord. Accordingly, neurologists had only one counsel for patients: "Try not to damage your brain, because there is no way to fix it."
This article was originally published with the title Brain, Repair Yourself.