Overeating may cause brain aging, whereas eating less turns on a molecule that helps the brain stay young. Giovambattista Pani, from the Catholic University of Sacred Heart (Italy), have discovered that a molecule, called CREB1, is triggered by "caloric restriction" (low caloric diet) in the brain of mice. As well CREB1 mediates the beneficial effects of the diet on the brain by turning on another group of molecules linked to longevity, known as sirtuins. CREB1 can be dramatically increased by simply reducing caloric intake:  if mice lack CREB1 the benefits of caloric restriction on the brain (improving memory, etc.) disappear, rendering animals without CREB1 with those brain disabilities typical of overfed and/or old animals. The study authors conclude that: “Circuitry [as] modulated by nutrient availability, links energy metabolism with neurotrophin signaling, participates in brain adaptation to nutrient restriction, and is potentially relevant to accelerated brain aging by overnutrition.”