A recent study revealed that the mechanism for regulating sleep in fruit flies uses an ingredient typically found in energy drinks. Although it doesn’t seem like it, fruit flies are very similar to humans. Like humans, they are active during the day and sleep at night. They also have identical snooze characteristics as people. Research carried out at the Florida Atlantic University have identified a new gene and a mechanism that regulates sleep in fruit flies by controlling the movement of taurine – an ingredient often found in energy drinks. Plenty of taurines can also be found in the human brain, and its levels are elevated in blood and urine of sleep-deprived individuals.
Every individual is aware of the importance of sleep for our physical and mental wellbeing. Rest is vital for immune function, metabolism, brain and muscle repair, learning and memory. Unfortunately, 30% of people will experience a sleep disorder throughout their life. All sleep disorders, no matter how harmless they seem, should be taken seriously because they are associated with a number of severe diseases such as diabetes, cardiovascular disease, and obesity.
In the past, scientists have believed that the glial cells only support neurons within the brain. However, new studies have revealed that these cells are essential for sleep regulation. The research teams of Florida Atlantic University and McGill University in Quebec had studied the fruit fly and discovered that glial cells and their ability to manage taurine are vital for regulating sleep. The fruit fly was chosen because it shares 75% of genes that cause various illnesses in humans, and although because we display similar behavioral and physiological characteristics of sleep. The study aimed to identify new genes that affect sleep and wakefulness in fruit flies. Scientists have uncovered a gene that is responsible for the membrane transport protein. This gene is called excitatory amino acid transporter 2 or shortly Eaat2.
Eaat2 increases wakefulness in fruit flies and actually limits their length and intensity of sleep. Sleep is regulated by controlling the movement of taurine into the glia. We already know that taurine is elevated in the blood and urine of sleep-deprived individuals, but we don’t know if taurine levels change after sleep deprivation. The authors of the study also found that disruption of Eaat2 in fruit flies causes excessive daytime sleepiness.
Since more than 70 millions of Americans suffer from sleep disorders, this kind of research is essential to raise awareness of the importance of sleep deprivation as a global issue and about understanding the fundamental mechanism of sleep. The identification of Eaat2 as a sleep regulator will help scientists to study further sleep regulation, sleep disorder treatment, and changes in metabolism that depend on sleep.
The scientists found that Eaat2 works only in specific glial cells of the fly brain. Glial cells play an important regulatory role and don’t just control the wakefulness of the fly, but also circadian rhythms. As mentioned before, Eaat2 regulates sleep by transporting taurine. Increased levels of taurine in the brain lead to excessive daytime sleepiness, and this claim was confirmed by an individual experiment which involved feeding fruit flies taurine. Future research aims to discover how transport of taurine to and from glial cells affects sleep in humans.