Summary: Scientists have identified the melatonin MT1 receptor as a key regulator of REM sleep, crucial for memory, dreaming, and emotional regulation. This discovery may pave the way for targeted treatments for sleep disorders and conditions like Parkinson’s and dementia, which are linked to REM disruptions.
Using a novel drug, researchers enhanced REM sleep duration in animal studies without negatively impacting overall sleep. The findings offer promising clinical potential for future therapies.
Key Facts:
- The melatonin MT1 receptor regulates REM sleep.
- REM sleep is essential for memory consolidation and emotional regulation.
- The discovery could lead to targeted treatments for sleep disorders and neuropsychiatric conditions.
Source: McGill University
A significant breakthrough in the understanding of sleep mechanism opens new promise for treating sleep disorders and associated neuropsychiatric conditions: Scientists have pinpointed the melatonin receptor MT1 as a crucial regulator of REM (Rapid Eye Movement) sleep.
REM sleep is crucial for dreaming, memory consolidation, and emotional regulation. In the brain, the melatonin MT1 receptor affects a type of neuron that synthesizes the neurotransmitter and hormone noradrenaline, found in an area known as the Locus Coeruleus, or “blue spot” in Latin.
During REM sleep, these neurons quiet down and stop their activity. Serious conditions such as Parkinson’s disease and Lewy body dementia — which currently lack effective treatments — are linked to disruptions in REM sleep.
“This discovery not only advances our understanding of sleep mechanisms but also holds significant clinical potential,” said Gabriella Gobbi, principal investigator of a new study published in the Journal of Neuroscience.
She is a Professor of Psychiatry at McGill University, clinician-scientist at the Research Institute of the McGill University Health Centre, and Canada Research Chair in Therapeutics for Mental Health.
The science of snoozing
Human sleep unfolds in a precise sequence of non-REM and REM stages, each serving distinct physiological functions. REM sleep plays a pivotal 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 vulnerability to neuropsychiatric diseases.
Until now, the specific receptor triggering REM sleep had eluded scientists. The new study has identified the melatonin MT1 receptor as an important regulator of this sleep stage.
Using a novel drug targeting MT1 receptors, researchers successfully enhanced REM sleep duration in experimental animals, while simultaneously reducing neuronal activity.
“Currently, there are no drugs specifically targeting REM sleep. Most hypnotic drugs on the market, while extending total sleep duration, tend to adversely affect REM sleep,” said Dr. Stefano Comai, co-senior author of the study and Professor at the University of Padua and Adjunct Professor at McGill University.
Further research into the neurobiology and pharmacology of REM sleep is crucial for developing targeted treatments that could improve the quality of life for patients affected by these debilitating diseases, according to the researchers.
As scientists continue to explore the complexities of sleep regulation, the hope for effective interventions in neurological disorders grow increasingly promising.
About this sleep, memory, and neuroscience research news
Author: Claire Loewen
Source: McGill University
Contact: Claire Loewen – McGill University
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Selective Enhancement of REM Sleep in Male Rats through Activation of Melatonin MT1 Receptors Located in the Locus Ceruleus Norepinephrine Neurons” by Gabriella Gobbi et al. Journal of Neuroscience
Abstract
Selective Enhancement of REM Sleep in Male Rats through Activation of Melatonin MT1 Receptors Located in the Locus Ceruleus Norepinephrine Neurons
Sleep disorders affect millions of people around the world and have a high comorbidity with psychiatric disorders.
While current hypnotics mostly increase non-rapid eye movement sleep (NREMS), drugs acting selectively on enhancing rapid eye movement sleep (REMS) are lacking.
This polysomnographic study in male rats showed that the first-in-class selective melatonin MT1 receptor partial agonist UCM871 increases the duration of REMS without affecting that of NREMS.
The REMS-promoting effects of UCM871 occurred by inhibiting, in a dose–response manner, the firing activity of the locus ceruleus (LC) norepinephrine (NE) neurons, which express MT1 receptors.
The increase of REMS duration and the inhibition of LC-NE neuronal activity by UCM871 were abolished by MT1 pharmacological antagonism and by an adeno-associated viral (AAV) vector, which selectively knocked down MT1 receptors in the LC-NE neurons.
In conclusion, MT1 receptor agonism inhibits LC-NE neurons and triggers REMS, thus representing a novel mechanism and target for REMS disorders and/or psychiatric disorders associated with REMS impairments.
