REM Sleep and the Crucial Role of Selective Melatonin Receptors

26.07.2024

A joint study by McGill, Padua and Toronto universities offers an important step forward in understanding the mechanisms of sleep. Published in Journal of Neuroscience Selective Enhancement of REM Sleep in Male Rats through Activation of Melatonin MT1 Receptors Located in the Locus Ceruleus Norepinephrine Neurons unveils new treatment of sleep disorders and associated neuropsychiatric conditions.

Human sleep occurs in a precise sequence of non-REM and REM phases, each of which performs distinct physiological functions. REM sleep plays a fundamental role in memory consolidation and emotion regulation. Non-REM sleep supports physical recovery and repair processes. Disruptions to this cycle can impair cognitive function and increase vulnerability to neuropsychiatric diseases.

Using a new drug that selectively acts on MT1 receptors, the research team managed to increase the duration of REM sleep in male rats, while simultaneously reducing the activity of noradrenergic neurons of the Locus Coeruleus.

The publication is the result of research on melatonin and its two receptors, MT1 and MT2, developed over the last 15 years by the scientific team. The authors identified the MT1 receptor as the crucial regulator of REM (Rapid Eye Movement) sleep and the results of the study led to the discovery of the first molecule capable of acting selectively on REM sleep without altering non-REM sleep.

Senior co-author of the research and professor of pharmacology at the University of Padua and adjunct professor at McGill University Stefano Comai explains, “Until now, no drugs specifically aimed at modifying REM sleep were known. Most hypnotic drugs on the market, while prolonging the total duration of sleep, tend to negatively influence REM sleep. With the published study -in addition to revealing the specificity of the melatonin MT1 receptor, we have discovered the first molecule capable of acting selectively on sleep REM sleep without affecting non-REM sleep.”

According to the research team, further studies into the neurobiology and pharmacology of REM sleep is essential to develop targeted treatments that could improve the quality of life of patients suffering from these debilitating neurodegenerative diseases. As scientists continue to explore the complexities of sleep regulation, the hope for effective interventions in neurological disorders becomes increasingly promising.