Study shows mouse brains can enter sleep-like state while awake

A study published in the journal Nature reports that parts of a mouse brain can be pushed into a sleep-like state while the animal remains awake. Researchers used genetically modified mice whose neurons could be controlled with light, triggering neural activity similar to non-rapid eye movement (NREM) sleep in specific brain regions after prolonged wakefulness. The team found that markers of neural fatigue dropped sharply in the stimulated regions. Study author Chiara Cirelli said the work was driven by the question of whether the brain could be guided into a state resembling deep sleep without losing consciousness, noting that some animals such as dolphins can sleep parts of their brain at a time. The stimulated brain areas did not appear to require compensatory sleep afterward, according to the researchers. Cirelli and her colleagues cautioned that the results are at an early stage and that ordinary sleep remains a biological necessity, leaving any broader applications to future research.