Humans, like all living creatures, are affected by light. Our bodily processes reset according to day/night patterns, even though we have inventions like fluorescent light and Starbucks that allow us to live outside natural boundaries.
Researchers now think they’ve identified the precise molecular mechanism by which light activates and deactivates our bodies. It’s a process called phosphorylation, where a phosphate combines with a protein (eIF4E) in the brain. The discovery is significant because it could lead to treatments for sleep disorders and perhaps give us more mastery of our circadian rhythms than we have now.
The research, led by teams at McGill and Concordia universities in Montreal, tested the importance of the protein by knocking out a single amino acid in mice, so it could no longer play a part in phosphorylation. Then the mutated mice were compared with normal mice in abnormal light/dark cycles (10.5 hours light/10.5 hours dark).
The mutant mice were much less respondent to light than the normal mice, indicating the importance of eIF4E and offering a potential way of manipulating body clocks (all animals have similar clocks apparently). The research is published in the journal Nature Neuroscience.
Ruifeng Cao, a postdoctoral fellow at McGill, says the next step is to look at resetting processes outside the brain as well. “It is now known that virtually every cell in every tissue of our body has a clock,” he says. “It would be rational to expect that [eIF4E phosphorylation] may play a similarly important role in the peripheral clocks. Then it could be used as a target to treat diseases associated with clock dysfunction such as jet lag.”
The disruption of our natural circadian rhythms, as prompted by our environment, is a serious health issue, with ramifications for everything from less-than-optimal sleep to serious disease (as we discussed here). Mastering how our bodies react to light would be a big step forward, potentially, though actual treatments are a long way off.