New Research from Tohoku University: Why Do Dreams Cause Fatigue?

A new study conducted at Tohoku University in Japan revealed that although blood and fuel flow to the brain increases during REM sleep, when dreams occur, the cellular energy (ATP) used directly by neurons is rapidly depleted.

Scientists have elucidated the biological mechanism behind the mental fatigue felt after vivid and intense dreams. Researchers simultaneously monitored the brain movements of mice in a natural state of sleep using special imaging techniques. The findings showed that there was a significant increase in blood flow from the back region of the brain to the front region, approximately 50 seconds before the classical REM phase began.

Despite this preparation, which increases the brain's fuel supply, and the increase in the level of pyruvate, the energy precursor, a sudden decrease was noted in the levels of ATP, the basic energy unit of neurons.

'DREAMING REQUIRES HIGH ENERGY CONSUMPTION'

The leader of the research team, Prof. Dr. Ko Matsui emphasized that dreams are not as relaxing a process as they think, and said, "Have you ever felt tired after a vivid dream? Although sleep seems peaceful from the outside, the brain is extremely active, especially during dreams. We wanted to understand the scientific basis behind this paradox, that is, why dreaming is tiring."

Scientists say that the decrease in neuronal energy; He stated that it results from memory consolidation, reorganization of synapses and intense information transfer between the hippocampus and cortex. Findings showing that the brain consumes energy much faster than it produces during dreams open the door to better understanding how biological intelligence manages limited metabolic resources and the critical role of sleep in the memory mechanism.