Scientists have unravelled the inner workings of melatonin, also known as the “sleep hormone,” making a major breakthrough for the development of new and promising treatments for insomnia.
The team from the Research Institute of the McGill University Health Centre (RI-MUHC) and McGill University revealed the key role played by the melatonin receptor in the brain that promotes deep, restorative sleep.
This discovery led the researchers to develop a novel drug called UCM765, which selectively activates this receptor.
The results may pave the way for the development of new and promising treatments for insomnia, a common public health problem that affects millions of people worldwide.
“We’ve spent many years to develop medications that act selectively on a single melatonin receptor to specifically promote deep sleep, which we believe is the key to curing insomnia,” said Dr. Gabriella Gobbi, a researcher in psychiatry at the RI-MUHC and the study’s principal investigator.
To date most treatments for insomnia, such as benzodiazepines, have not been selective for deep sleep, and can lead to dependence and cognitive impairment.
The research team discovered that two principal melatonin receptors, known as MT1 and MT2, played opposite roles in sleep regulation.
“We discovered that MT1 receptors act on rapid eye movement (REM) sleep and block non-REM sleep, while MT2 receptors favour non-REM sleep, also known as deep sleep,” explained Dr. Gobbi.
“Specifying the role of MT2 receptors in melatonin represent a major scientific breakthrough that may designate them as a promising novel target for future treatments of insomnia. This discovery also explains the modest hypnotic effect of the over-the-counter melatonin pills, which act on both conflicting receptors,” he added.
The finding has been published in The Journal of Neuroscience.