A mental workout

A mental workout
Heavy thinking can tire you out almost as much as strenuous physical labor, and the older you are, the more that is true, researchers at the University of Illinois in Urbana have found. Though the research focused on rats, the results also apply to humans, said Paul Gold, a psychology professor. Gold and his colleagues found that when rats concentrate on certain tasks, the parts of their brains they must use require glucose as fuel to do the necessary thinking. Glucose flows more freely in the brains of young rats but not in the brains of older animals, the researchers found.
Making a splash
Wild gorillas have been observed using water to make splash displays. The splashes were made by western lowland male gorillas in the Congo and were probably intended to intimidate potential rivals for females, a new study says. The males ran and leaped into the water, creating a splash, or used one or both hands to splash the water. The study, in the current issue of Nature, is the first record of gorillas using water to communicate and the only known instance of a nonhuman primate directly manipulating water with its body for this purpose.