A research team recently discovered that the DNA of individual human brain cells varies from cell to cell. Apparently, there are certain segments of our DNA that can get copied multiple times in our brain cells. In other types of cells, this mechanism is turned off. This seems like a very important discovery. Until now, we thought that the DNA in our cells was relatively static. Now it seems, the DNA of our brain cells is dynamic. This mechanism must serve some purpose, but that has not been discovered yet.