Study reveals sleep is triggered by energy overload in brain cells

A recent study from the University of Oxford has identified a biological trigger for sleep linked to energy overload in brain cells. Researchers led by Professor Gero Miesenböck and Dr. Raffaele Sarnataro found that mitochondria—the cell’s energy-producing structures—generate reactive oxygen species (ROS) when overwhelmed by excess energy. This electron leak signals specialized neurons, which act like circuit breakers, to initiate sleep. The sleep response allows brain cells to reset and prevent damage from oxidative stress caused by these reactive molecules. Experiments in fruit flies demonstrated that manipulating mitochondrial energy flow directly affected sleep duration, confirming the connection between cellular energy metabolism and sleep regulation. The findings provide a new understanding of why sleep is necessary, linking it to the fundamental process of aerobic metabolism. This mechanism may also explain the relationship between metabolism, sleep, aging, and fatigue. For example, animals with higher oxygen consumption tend to sleep more and have shorter lifespans, while humans with mitochondrial disorders often suffer from chronic fatigue