The man who unlocked REM
Dr. Michel Jouvet, a neurophysiologist who discovered the region of the brain that controls rapid eye movement and who helped define REM sleep as a unique state of consciousness common to humans and animals alike, died on Oct. 3 in Villeurbanne, France. He was 91.
The curious physiological phenomenon known as REM sleep was first reported in the early 1950s by researchers at the University of Chicago. They noticed that people who appeared to be sleeping soundly sometimes moved their eyes, and that electroencephalogram recordings showed that brain activity during periods of eye movement was closer to that of someone awake. They eventually determined that sleepers had intermittent periods of REM during which they often dreamed.
Jouvet was a researcher at the University of Lyon in France, studying how sleeping cats react to stimuli, before he turned his attention to REM in the late 1950s.
In deep sleep, both cats and humans show slight muscle tension and low brain activity. But Jouvet found that during periods of REM sleep the muscles of cats were completely slack, even though their brain waves suggested physical activity.
He determined that a structure within the brain stem called the pons governed cats’ REM sleep.
The pons is responsible for basic biological functions, like breathing and sensory perception.
Many researchers at the time assumed that since dreaming seemed to be complex, it would be centralized in the part of the brain responsible for reasoning. Jouvet’s discovery suggested that REM sleep could continue without the involvement of higher brain structures and that it had an important biological function even for animals with little capacity for reasoning.