A new study led by Florida Atlantic University researchers found that a gene called translin controls sleep in response to metabolic changes, such as starvation. This explains why a person cannot sleep if he is hungry.
“While many genes have been identified as genetic regulators of sleep or metabolic state, mounting evidence from our study indicates that translin functions as a unique integrator of these processes,” says co-first author Kazuma Murakami. “We also have been able to show that this gene is not required for general modulation of sleep.”
“In humans, sleep and feeding are tightly interconnected, and pathological disturbances of either process are associated with metabolism-related disorders,” asserts study author Alex Keene, an associate professor in the Department of Biological Sciences at the university. “Despite the widespread evidence for interactions between sleep loss and metabolic dysfunction, little is known about the molecular basis of this interaction and how these processes integrate within the brain.”
They studied fruit flies because their sleep habits are similar to that of humans. When these insects are hungry, they do not sleep until they find food.
The fruit flies were fed with a specific diet for this study. Their sleep, glycogen, triglycerides and free glucose levels have been measured.
Based on their nervous system-specific RNAi screen, the team have discovered that translin causes this wakefulness in starving fruit flies. When suppressed, the flies were able to sleep like how they would on a full stomach.
“Furthermore, we now know that the energy stores in mutant flies are normal and that the starvation-induced sleep suppression phenotype is not due to an increased nutrient storage,” adds Murakami.
The researchers point out that translin only causes wakefulness when one is hungry but does not cause the perception of starvation nor hunger-related behaviours or modulate sleep. Nevertheless, Keene says that this study has implications beyond starvation-induced sleep deprivation because it can also offer new understanding into how the brain integrates and manages behaviours.