A recent study published at Science.org has shed new light on the origin of our primal need to sleep. Researchers examined the brains of exhausted fruit flies and discovered that the signal to sleep may come from within our mitochondria, the energy-producing structures within cells.
The scientists found that 122 genes were activated in the sleep-control spot of the flies’ brains when they were tired, indicating a desperate attempt to repair damaged cellular batteries. By manipulating the speed of energy production, the researchers could induce sleepiness or wakefulness in the flies.
This breakthrough discovery transforms our understanding of fatigue from a vague feeling to an energy-crisis alarm. It also sheds light on why illnesses that affect cellular power plants can lead to debilitating exhaustion.
Source: https://boingboing.net/2025/07/30/scientists-discover-why-your-brain-demands-sleep.html