Separate studies reveal the mechanisms by which brain cells assume their rightful places.
Magdalena Götz at the University of Munich in Germany and her colleagues manipulated a single DNA-associated protein to promote folding in a normally smooth region of mouse brain. Low levels of the protein cause cells to divide along one plane, and high levels cause division along another. Regulation of the protein, in turn, permits complex folding that creates more room for the cerebral cortex, the layer of neural tissue covering the cerebrum. Meanwhile, researchers led by Dwight Bergles at Johns Hopkins University School of Medicine in Baltimore, Maryland, showed how precursor cells maintain a constant density of neural support cells as these cells differentiate and die. The team used time-lapse imaging of adult mouse brains to reveal that the mobile precursor cells constantly survey their environments and avoid each other, establishing a grid-like distribution throughout the nervous system.