Clocks on the Brain

Abstract
In many animals, circadian oscillators in the brain and periphery synchronize gene expression and behavior with the 24-hour day:night cycle. In their Perspective, Green and Menaker discuss new work ( Dudley et al.), which shows that the master oscillator in the hypothalamus, the suprachiasmatic nucleus, cooperates with an oscillator in the forebrain to synchronize circadian behavior in mice.