A major breakthrough in the understanding of the sleep mechanism opens up new possibilities for the treatment of sleep disorders and associated neuropsychiatric diseases: Scientists have identified the melatonin receptor MT1 as a crucial regulator of rapid eye movement (REM) sleep.

The Importance of REM Sleep

REM sleep is very important for dreaming, memory consolidation and emotional regulation. In the brain, the melatonin MT1 receptor influences a type of neuron that synthesizes the neurotransmitter and hormone norepinephrine, which is found in an area known as the locus coeruleus or “blue spot” in Latin. During REM sleep, these neurons calm down and cease their activity. Severe diseases such as Parkinson’s disease and Lewy body dementia, for which there are currently no effective treatments, are linked to REM sleep disorders.

This discovery not only expands our understanding of sleep mechanisms, but also holds significant clinical potential, according to Gabriella Gobbi, lead researcher of a new study published in the Journal of Neuroscience. She is a professor of psychiatry at McGill University, a clinician-scientist at the McGill University Health Centre Research Institute and holds the Canada Research Chair in Therapeutics for Mental Health.

Drug That Targets REM Sleep

Human sleep follows a precise sequence of non-REM and REM phases, each of which fulfills different physiological functions. REM sleep plays a crucial role in memory consolidation and emotional regulation. Non-REM sleep supports physical recovery and repair processes. Disruptions in this cycle can impair cognitive function and increase susceptibility to neuropsychiatric disorders. Until now, the specific receptor that triggers REM sleep had eluded scientists. In the new study, the melatonin MT1 receptor was identified as an important regulator of this sleep phase. Using a novel drug that targets MT1 receptors, the researchers were able to successfully prolong the duration of REM sleep in experimental animals while reducing neuronal activity.

“Currently, there are no drugs that specifically target REM sleep. Most sleep medications on the market prolong overall sleep duration but tend to impair REM sleep,” said Dr. Stefano Comai, co-senior author of the study and professor at the University of Padua and associate professor at McGill University. According to the researchers, further research into the neurobiology and pharmacology of REM sleep is crucial for the development of targeted treatments that could improve the quality of life of patients affected by these serious diseases. As scientists continue to explore the complexities of sleep regulation, there is growing hope for effective interventions for neurological disorders.