The more I learn about circadian rhythms, the more research I want pursued on the topic. The results of three recently published studies reinforce my belief that gaining a greater understanding of the mechanisms behind our body clocks will solve important mysteries with relation to sleep and overall health maintenance throughout life.
The first study that caught my attention was conducted with mice. University of California, Los Angeles (UCLA) researchers found that eating at times normally reserved for sleep causes a deficiency in the type of learning and memory controlled by the hippocampal area of the brain.1 “We have provided the first evidence that taking regular meals at the wrong time of day has far-reaching effects for learning and memory,” says first author Dawn Loh in a release. “Since many people find themselves working or playing during times when they’d normally be asleep, it is important to know that this could dull some of the functions of the brain.” The findings have not been confirmed in humans, the researchers stress, but I envision studies such as this ultimately pointing toward solutions to help those with shift work-related cognitive concerns.
There are many puzzles related to sleep and aging, and a study by researchers at the University of Pittsburgh has implications for clinical care for age-related problems associated with circadian rhythms.2 While some daily rhythms deteriorate and shift forward as humans age, this study also found a set of genes that actually gained rhythmicity in older individuals. As senior investigator Colleen McClung, PhD, told The New York Times, “It looks like the brain might be trying to compensate by turning on an additional clock.” This information could ultimately help develop treatments for age-associated sleep problems and may even lead to humans being able to turn on and off a backup internal clock.
The third study that captured my interest was led by researchers at the University of Texas Southwestern Medical Center and UCLA and identified a dozen inherited traits related to sleep, wake, and activity cycles that are linked with severe bipolar disorder.3 Causes of bipolar disorder are thought to be both genetic and environmental, and researchers have long suspected that disruption in normal daily circadian rhythms can precede mood shifts. “This study represents a key step in identifying the genetic roots of this disorder and, in turn, providing targets for new approaches to preventing and treating bipolar disorder,” says UCLA’s Nelson Freimer, MD. The link between circadian rhythms, sleep, and psychiatric illnesses is one that could yield more efficacious treatments in the future.
What spurred my initial fascination in harnessing circadian rhythms is the boost in productivity I have observed in my own life using the basic knowledge I have picked up from reading 2+ years of study abstracts on the workings of internal clocks. Simply planning my most challenging daily tasks for the 10 am hour, my most creative assignments for the afternoon, and taking a nap (when my schedule permits) around 3 pm has caused a noticeable increase in my workday efficiency. If working cooperatively with natural daily rhythms can have such a positive impact on a healthy subject, I am eager to find out more about what understanding body clocks can accomplish to heal those with diseases and disorders.
Sree Roy is editor of Sleep Review.
1. Loh DH et al. Misaligned feeding impairs memories. eLife 2015;4:e09460.
2. Chen CY et al. Effects of aging on circadian patterns of gene expression in the human prefrontal cortex. PNAS;published ahead of print December 22, 2015.
3. Pagani L et al. Genetic contributions to circadian activity rhythm and sleep pattern phenotypes in pedigrees segregating for severe bipolar disorder. PNAS Early Edition 2015. doi: 10.1073/pnas.1513525113