Lipids make smooth brains gyrate.

The surface area of the cerebral cortex has increased massively during mammalian evolution and this change has been accompanied by folding of the cortical sheet into gyri. The molecular mechanisms that control cortical size are poorly understood. A recent study suggests that the regulation of cortical size might involve phospholipids, by showing that their addition to cultured embryonic mouse cortices increases cortical size and induces folds resembling gyri.