This sea animal may settle a long-running debate about what sleep is needed for
A new study suggests jellyfish may hold the answer to why we need sleep
- A new study in Nature Communications reveals that jellyfish and sea anemones, despite lacking complex brains, exhibit sleep-like states.
- Researchers discovered that DNA damage accumulates in the nerve cells of these invertebrates during wakefulness, and this damage is subsequently repaired while they are dozing.
- This finding suggests that the fundamental purpose of sleep, particularly for cellular self-defense and DNA repair, dates back over 600 million years, predating the evolution of complex brains.
- Experiments showed that these creatures display reduced responsiveness during rest, and sleep deprivation led to an increase in DNA breaks, followed by a 'sleep rebound' effect.
- The sleep hormone melatonin was also found to induce sleep in these brainless animals, indicating that its soporific role evolved much earlier than previously understood.