{
  "id": 91570,
  "title": "How Dreaming Drains Your Energy",
  "url": "https://urgent.news/2026/08/03/how-dreaming-drains-your-energy",
  "topic": "science",
  "section": "Science",
  "published": "2026-08-03T16:00:00.000Z",
  "source": {
    "name": "Nautilus",
    "slug": "nautilus",
    "url": "https://nautil.us/how-dreaming-drains-your-energy-1283306/"
  },
  "original_language": "en",
  "account": "A team of Japanese neuroscientists from Tohoku University sought to understand why dreams can leave individuals feeling drained rather than rejuvenated. By imaging the brains of dreaming mice, they discovered two paradoxes related to brain energy consumption. Firstly, while dreamers' brains appear highly active during REM sleep, similar to the awake state, the brain's energy stores rapidly decline. Secondly, they found that blood circulation plays a larger role than previously thought in determining brain behavior.\n\nProfessor Ko Matsui, one of the study authors, explains that the brain's energy supply is primarily through blood, which carries oxygen and glucose. However, neurons, which consume significant energy, don't directly contact blood vessels but rely on astrocytes for intermediary energy delivery. The study revealed that during REM sleep, blood vessels expand, increasing energy supply to neurons, yet ATP, the energy molecule neurons use, decreases. This suggests either neurons consume more energy, energy delivery is suspended, or neurons halt ATP conversion.\n\nComparing REM sleep to waking activities, the brain uses a lot of energy regardless of the activity. About 2% of the body's weight, the brain consumes about 20% of the body's energy. A 50-second pre-REM surge in blood flow, when the brain is prepared for intensive energy use, supports this notion. This finding contradicts the notion that neurons alone dictate brain activity, highlighting the brain-heart connection in mind operations. According to Matsui, \"Decisions are also shaped by the metabolic landscape that the blood creates.\"",
  "summary": "The brain makes its bed long before we dream, and the neurons don’t call all the shots The post How Dreaming Drains Your Energy appeared first on Nautilus .",
  "key_points": [
    "Dreaming mice's brains appear highly active during REM sleep, similar to awake state.",
    "Blood circulation plays larger role than thought in determining brain behavior.",
    "REM sleep increases blood vessels, yet ATP decreases, suggesting energy consumption paradox."
  ],
  "editors_take": "The discovery that brain energy drains during REM sleep despite increased blood flow reveals a complex interplay between neurons, astrocytes, and blood vessels that challenges assumptions about brain activity and energy use.",
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}