Reversing Age-Related Sleep Problems
With increasing age, many people experience a decline in sleep quality that in turn reduces their quality of life. In a study publishing April 1st 2014 in the journal PLOS Biology, scientists at the Max Planck Institute (MPI) for Biology of Aging in Cologne, Germany present findings that suggest that age-related sleep decline can be prevented and might even be reversible.
A release from the publisher explains that to uncover basic age-related sleep mechanisms, the team studied the fruit fly Drosophila melanogaster, a classical model organism in aging research. "Drosophila's sleep has many features in common with that of humans, including the decline in quality", says Luke Tain of the MPI for Biology of Aging. "Like humans, flies sleep at night and are active during the day. We can observe when and how long flies sleep. We can also determine their sleep quality by measuring how often they wake. This allows us to study the effects of specific substances or other sleep-influencing factors such as age and genetic disposition."
The researchers, discovered that a reduced activity in a specific signaling pathway leads to improved sleep quality at night and higher activity levels at day. A signaling pathway is a biological method of transferring information, and via those pathways the cell can respond to external conditions such as the state of food supply. "In our study, we described the role of the IIS pathway in regulating sleep and activity through the neurotransmitters octopamine and dopamine", explains Tain. "What makes this pathway so interesting to us is the fact that it is evolutionarily conserved. This means that its components and functions are similar in diverse species from simple organisms like fruit flies to mice and even humans. Furthermore, we were able to improve sleep quality by administering therapeutic agents."
Moreover, the scientists found out that day activity and night sleep are regulated by two distinct signaling pathways, night sleep being mediated through TOR and dopaminergic signaling. Surprisingly, if TOR's activity is acutely inhibited by treatment with the therapeutic agent Rapamycin, sleep quality improves even in old flies, suggesting that age-related sleep decline is not only preventable but also reversible.
The scientists will follow up on their findings. "Given the high evolutionarily conservation of IIS and TOR function, our results implicate potential therapeutic targets to improve sleep quality in humans, said research Luke Tain. “This would be our longer-term goal. The next step however, is to find out whether these mechanisms also work in higher animals like mice."