A French researcher has been awarded for discovering the cause of narcolepsy

It is a “rare”, “incredible” but also “devastating” disease that causes affected patients to “suffer terribly”. The Frenchman Emmanuel Mignot devoted his career to the study of narcolepsy until he found its cause and shed light on one of the great mysteries of biology – sleep.

His discovery at the heart of the brain’s convolutions earned him an important prize in the United States, the Breakthrough Prize, along with the Japanese Masashi Yanagisawa, who reached similar conclusions at the same time. Thanks to their research, drugs are currently being developed that promise to revolutionize the treatment of this and other sleep disorders.

Narcoleptics, which are about one in 2,000 people, cannot help but fall asleep suddenly. Some are also affected by sudden temporary paralysis (cataplexy).

“I am very proud because what I have discovered makes a big difference for my patients. This is the best reward that can be received, “said the university professor from Stanford, California, to whose office narcoleptics come from all over the world. 30 years ago Fresh out of his medical and science degrees, Mignot decided to travel to the United States during his military service to study the effects of a drug then being used against narcolepsy.

The disease was “virtually unknown” and “no one was studying it,” he recalled. But he “was completely fascinated.” “I thought: this disease is amazing, people fall asleep all the time, we have no idea why, and if we can find the cause, we could understand something new about sleep,” explained the 63-year-old researcher.

the lost key

Stanford had narcoleptic dogs at the time, and Mignot set out to find the gene that causes the disease. A titanic undertaking because at the time genome sequencing techniques were primitive. “Everyone told me I was crazy,” recalls the scientist, who now lives with Watson, a narcoleptic dog he adopted.

“I thought it would take a few years, but it took 10.” Finally, in 1999, the discovery came: a receptor located in brain cells that functions abnormally in narcoleptic dogs. This receptor is like a lock that reacts only in the presence of the right key, that is, a molecule discovered at the same time by the Japanese Masashi Yanagisawa, who called it orexin, also called hypocretin.

A neurotransmitter produced in the hypothalamus, at the base of the brain, by a very small population of neurons. Migno immediately performed the first tests on humans. And the results were impressive. For example, that orexin levels in the brains of narcolepsy patients are zero.

Normally, this molecule is produced in large quantities throughout the day, especially in the afternoon, which makes it possible to fight accumulated fatigue. Dogs have the lock broken, but humans lack the key to open it. This difference explains why the disease can be inherited in dogs but not in humans. “You can’t make a discovery like this twice in your life. Find the cause of the disease,” emphasized the Frenchman.

A miracle cure

Currently, most patients are treated with a combination of anesthetics for deep sleep at night and amphetamines for waking during the day. But when a drug that mimics orexin was given in the trials, the results were “truly miraculous,” Mignot says.

The patients had a real “transformation” and saw with “different eyes”. They were “calm,” says the scientist. The challenge remains to develop a formula that delivers the right dose at the right time. Several companies, including Japan’s Takeda, are working on the issue, and some drugs may be licensed in the next few years.

*With information from AFP.

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