Scientists have long recognized melatonin as a key hormone in preparing the body for sleep, but a lesser-known chemical called orexin plays the opposite role by promoting wakefulness. In 1999, two researchers independently identified the function of orexin, fundamentally changing our understanding of sleep regulation. Dr. Masashi Yanagisawa, a molecular biologist at the University of Tsukuba, made the discovery while investigating brain receptor interactions. Meanwhile, Dr. Emmanuel Mignot, director of the Stanford Center for Narcolepsy, was studying the condition in dogs, including his own Chihuahua, Watson, and a previous dog named Bear.
This year, Yanagisawa and Mignot were honored with the Albert Lasker Basic Medical Research Award for their foundational work. Their findings have since paved the way for new treatments for both insomnia and narcolepsy. In an interview with Live Science, Mignot discussed the origins of his research and the future of sleep science.
Mignot explained that three factors drew him to narcolepsy. First, he noted that although the disorder affects approximately 1 in 3,000 people, it was largely overlooked by the medical community. Second, he viewed it as a quintessential sleep disorder that could reveal new insights into how sleep works. Third, he believed the condition was scientifically tractable.
Initially trained in pharmacology, Mignot realized early on that studying drugs alone would not reveal the root cause of narcolepsy. Consequently, he shifted his focus to genetics despite not having a formal background in the field. He reasoned that since dogs exhibited all the symptoms of the disease, identifying the responsible gene in canines was the logical path forward. This endeavor took a decade of persistent effort.
The use of dogs in this research has a long history at Stanford. Dr. William Dement, who founded the university’s sleep program, learned in the 1970s about a dog that collapsed when excited, exhibiting symptoms similar to human narcolepsy. This led to the creation of a dog colony, which eventually included genetic forms of the disorder found in Doberman and Labrador Retrievers. When Mignot arrived in 1987, this existing colony allowed him to build upon previous work.
Mignot described the genetic challenges of the time as significant, noting that the canine genome was barely understood compared to human or mouse models. Despite skepticism from some peers who doubted the dogs truly had narcolepsy, he remained convinced of the approach. The discovery of the orexin receptor proved to be a major breakthrough, offering a direct drug target applicable to humans.
Following the publication of the dog gene discovery, awareness of narcolepsy surged. Mignot observed that doctors began diagnosing children more frequently, revealing that the condition often presents differently in youth than in adults, with rapid weight gain and abrupt onset. Additionally, pharmaceutical companies quickly developed hypnotics that block orexin, which are considered potentially safer than benzodiazepines because they mimic the natural drop in wakefulness-promoting signals during sleep.
The research also advanced the understanding of the autoimmune component of narcolepsy. Earlier work by Japanese researcher Yutaka Honda linked the disorder to the HLA-DR2 genetic variant. Mignot later refined this by identifying the DQB1*06:02 gene as a more precise marker, particularly in African American populations. This study is credited as an early example of transethnic mapping.
Recent approvals of orexin-targeting therapies have validated Mignot’s earlier findings. He reported seeing dramatic improvements in his patients and expressed optimism about broader applications, including potential benefits for ADHD and depression-related sleepiness. He also noted promising results in patients with both narcolepsy and schizophrenia, where traditional stimulants can worsen hallucinations but orexin-activating drugs may improve motivation and alertness without such side effects.
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