Gene activity in the brain suggests off-kilter circadian rhythms
The disruption of sleep and other bodily rhythms that often accompanies clinical depression may leave a mark on the brain. A study of gene activity in the brains of people who suffered from depression reveals that their daily clocks were probably out of whack. The results appear May 13 in the Proceedings of the National Academy of Sciences.
“This is really important work, amazing work,” says Noga Kronfeld-Schor, a physiologist who specializes in circadian rhythms at Tel Aviv University. “There’s been indirect evidence, but this clearly shows a connection between disrupted circadian cycles and depression.”
In mammals, daily rhythms such as sleep, hormone cycles and eating patterns are guided by a master clock in the brain whose rhythms are maintained in part by genes and patterns of light and darkness. The master clock can get out of sync with clocks elsewhere in the brain and body. This discord, for example, produces th