While humans have invented a convention called time keeping to make society work, our bodies themselves also have a sort of clock called an internal biologic clock or circadian rhythm. When met by daylight, hormones are released that keep us awake and alert, while darkness releases different hormones that puts us to sleep. Canadian researchers have now found the molecular switch that resets and synchronizes the circadian clock. A drug that tweaks this switch could thus be made that regulates the internal clock, something travelers and night owls might find particularly useful.
Setting the clock
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Nahum Sonenberg, a biochemist from McGill University in Quebec, and colleagues found light resets the internal clock by triggering phosphate to combine with a protein found in the brain called eIF4E. This process is called phosphorylation. The researchers engineered mice whose eIF4E couldn’t be phosphorylated, then tuned the lighting inside a cage from a 12-hour cycle to a 10.5-hour cycle, a relatively minor adjustment. Control group mice which weren’t engineered adapted quite quickly, but the mutants behaved like on jet-lag. Upon further inspection, the team found that phosphorylation eIF4E increases the output of Period proteins which are known for driving circadian rhythms in eclosion and locomotor activity, as reported in Nature Neuroscience.
“This study is the first to reveal a mechanism that explains how light regulates protein synthesis in the brain, and how this affects the function of the circadian clock,” said Sonenberg.
Image: AP Biology
“Disruption of the circadian rhythm is sometimes unavoidable but it can lead to serious consequences. This research is really about the importance of the circadian rhythm to our general well-being,” said co-author Shimon Amir. “We’ve taken an important step towards being able to reset our internal clocks – and improve the health of thousands as a result.”
We live in a really busy world, and with all the benefits that technology brought, there are also many health problems that come with it. Too much artificial light or staring in your computer screen on facebook until 1 AM definitely doesn’t help since it tricks the internal clock. This is why you might find it hard to wake up in the morning or constantly feel exhausted. Most of us can’t go back to waking up at first dusk and sleeping at nightfall though, like out great grandparents had. A drug that tweaks with eIF4E activity might regulate our internal clocks and actually synchronize our bodies with our 21st century lifestyle.
