Tohoku University study links dreaming to brain energy depletion

Research conducted at Tohoku University in Japan has identified a biological mechanism explaining why vivid dreaming can lead to morning fatigue. The study reveals that during REM sleep, the brain consumes cellular energy (ATP) much faster than it can be replenished, despite an increase in blood and fuel flow to the brain.

Using advanced imaging techniques on sleeping mice, researchers observed a significant increase in blood flow from the back to the front of the brain approximately 50 seconds before the classic REM stage begins. However, even with rising pyruvate levels, there was a sharp drop in ATP, the fundamental energy unit of neurons.

Lead researcher Prof. Dr. Ko Matsui noted that while sleep appears peaceful from the outside, the brain is extremely active during dreaming. The energy depletion is attributed to intense processes such as memory consolidation, synaptic reorganization, and information transfer between the hippocampus and the cortex.