Those trying to lose weight and overcome addictions could be helped by having their brain activity partly blocked during the ‘dreaming’ stage of sleep, a study found.
Experts from Switzerland found that using light pulses to shut down neurons in the hypothalamus region of the brain during rapid eye movement (REM) sleep reduced appetite.
Located at the base of the brain, the hypothalamus is involved in various biological processes — from feeding behaviours to pain perception and temperature control.
Those trying to lose weight and overcome addictions could be helped by having their brain activity slowed down during the ‘dreaming’ stage of sleep, a study found (stock image)
As we slumber, we pass between different phases of sleep, each of which are thought to make a different contribution to our nightly rest.
REM — sometimes referred to as the ‘paradoxical’ stage of sleep for its similarity with waking brain activity — is the phase within which most dreaming occurs.
When in REM sleep, high levels of electrical activity can be measured in various parts of the brain — including in areas that serve to regulate memory or emotion — but the exact purpose of this activity has long remained unclear, experts said.
In their study, paper author and neuroscientist Lukas Oesch of the Inselspital University Hospital Bern and colleagues have determined that the activation of neurons in the hypothalamus during the REM phase of sleep regulates eating.
In a technique known as ‘optogenetics’, the team used light pulses to precisely shut down the activity of neurons in the hypothalami of mice undergoing REM sleep.
The team found that specific activity patterns of neurons in the lateral hypothalamus that fire when hungry and during eating also appear during the REM stage — and that suppressing this activity led to the mice eating less when they woke.
The same neurons are also involved in the regulation of both motivated behaviours and addiction, the researchers noted.
Found at the base of the brain, the hypothalamus (depicted here in a human ) controls many biological processes, from feeding behaviours to pain perception and temperature control
‘We were surprised how strongly and persistently our intervention affected the neural activity in the lateral hypothalamus and the behaviour of the mice,’ Mr Oesch commented.
‘The modification in the activity patterns was still measurable after four days of regular sleep.’
The findings suggest that electrical activity in hypothalamic circuits during REM sleep are essential to maintain a stable feeding behaviour in mammals — and, moreover, that they can be easily shaped.
Further, the results highlight how getting a good night’s sleep plays a major role in maintaining appropriate eating behaviour.
The findings ‘suggests that REM sleep is necessary to stabilise food intake,’ said paper author and neuroscientist Antoine Adamantidis of the University of Bern.
‘This is of particular relevance in our society where not only sleep quantity decreases but where sleep quality is dramatically affected by shift work, late night screen exposure or social jet-lag in adolescents,’ he added.
The findings, the team said, could help to develop new therapies to treat both eating disorders as well as addiction.
‘However, this relationship might depend on the precise circuitry, the sleep stage and other factors yet to be uncovered,’ Prof Adamantidis cautioned.
The full findings of the study were published in the journal Proceedings of the National Academy of Sciences.