How the brain’s daily clock controls mood: A new project

ANN ARBOR, Mich.-A math professor at the University of Michigan will lead an international, $1 million project examining the links between bipolar disorder and abnormalities in the circadian, or daily, rhythms of a mammal's internal clock. In humans, this grain-of-rice-sized timepiece is a cluster of 20,000 neurons right behind the eyes. It's called the suprachiasmatic nucleus (SCN) of the brain's hypothalamus, and it is responsible for keeping our bodies in synch with our planet's 24-hour day. Scientists believe it's off kilter in patients with bipolar disorder. Some of the genes implicated in the disease are the same ones that regulate the biological clock. The common treatment drug lithium is known to change the period of that clock, and when manic patients are forced to stay on a 24-hour schedule, many experience a reprieve from the episode, said principal investigator Daniel Forger, an associate professor in the U-M Department of Mathematics. Exactly how the brain's clock controls mood remains a mystery, though.