http://psychcentral.com/news/2015/12/25/circadian-rhythm-of-genes-changes-with-age/96730.html

Circadian Rhythm of Genes Changes with Age
By Traci Pedersen

The circadian rhythm of gene activity changes with age, according to new study at the University of Pittsburgh School of Medicine that examined thousands of genes from nearly 150 human brains. The findings also suggest that a novel biological clock emerges in the older brain.

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“As we expected, younger people had that daily rhythm in all the classic ‘clock’ genes,” Dr. McClung said. “But there was a loss of rhythm in many of these genes in older people, which might explain some of the alterations that occur in sleep, cognition and mood in later life.”

To their surprise, the team also found a set of genes that gained rhythmicity in older individuals.

The findings could contribute to the development of treatments for cognitive and sleep problems in older people, as well as a potential treatment for “sundowning,” a condition in which older dementia patients become agitated, confused and anxious in the evening.

“Since depression is associated with accelerated molecular aging, and with disruptions in daily routines, these results also may shed light on molecular changes occurring in adults with depression,” said Sibille.

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