Nav: Home

Genes that regulate how much we dream

August 28, 2018

Sleep is known to allow animals to re-energize themselves and consolidate memories. Rapid eye movement (REM) sleep, a mysterious stage of sleep in which animals dream, is known to play an important role in maintaining a healthy mental and physical life, but the molecular mechanisms behind this state are barely understood. Now, an international research team led by researchers at the RIKEN Center for Biosystems Dynamics Research (BDR) in Japan has identified a pair of genes that regulate how much REM and non-REM sleep an animal experiences.

Sleep is a universal and vital behavior in animals. In higher vertebrates such as mammals and birds, sleep is classified into two phases, rapid eye movement (REM) sleep and non-REM sleep. During REM sleep, our brain is as active as it is during wakefulness, and this stage is believed to function in memory consolidation. Although our knowledge of the neural mechanisms underlying sleep has gradually advanced, the essential molecular factors that regulate REM sleep are still unknown. Now, however, a research team led by Hiroki Ueda at RIKEN BDR and The University of Tokyo has identified two essential genes involved in the regulation of REM sleep. The amount of REM sleep was drastically decreased down to almost undetectable levels when both genes were knocked out in a mouse model. This study was published by Cell Reports on August 28.

Several past studies have suggested that acetylcholine--the first identified neurotransmitter--and its receptor are important for the regulation of REM sleep. Acetylcholine is abundantly released in some parts of mammalian brain during REM sleep and wakefulness. However, it was unclear which receptor or receptors were directly involved in the regulation of REM sleep due to the complexity of the underlying neural network.

For this study, the researchers used cutting-edge genetic tools to modify mouse genes and conduct genetic screening for factors whose inhibition would cause sleep abnormalities. After knocking out a number of genes encoding various acetylcholine receptors, they found that the loss of two receptors--called Chrm1 and Chrm3--induced a characteristic short-sleep profile. These two receptors are widely distributed in distinct brain regions. The knockout of Chrm1 reduced and fragmented REM sleep, whereas knocking out Chrm3 reduced the length of non-REM sleep. When both genes were knocked out, mice failed almost entirely to experience REM sleep, but survived nonetheless.

"The surprising finding that mice are viable despite the almost complete loss of REM sleep will allow us to rigorously verify whether REM sleep plays a crucial role in fundamental biological functions such as learning and memory" says Yasutaka Niwa, the co-first author of this article.

These findings strongly suggest that these two receptors are essential for sleep regulation, especially REM sleep, and function in different ways. "The discovery that Chrm1 and Chrm3 play a key role in REM sleep opens the way to studying its underlying cellular and molecular mechanisms and will eventually allow us to define the state of REM sleep, which has been paradoxical and mysterious since its original report," Ueda says.
-end-
Reference:

Niwa Y et al. (2018) Muscarinic acetylcholine receptors Chrm1 and Chrm3 are essential for REM sleep. Cell Reports. doi: 10.1016/j.celrep.2018.07.082.

RIKEN

Related Sleep Articles:

Wind turbine noise affects dream sleep and perceived sleep restoration
Wind turbine noise (WTN) influences people's perception of the restorative effects of sleep, and also has a small but significant effect on dream sleep, otherwise known as REM (rapid eye movement) sleep, a study at the University of Gothenburg, Sweden, shows.
To sleep deeply: The brainstem neurons that regulate non-REM sleep
University of Tsukuba researchers identified neurons that promote non-REM sleep in the brainstem in mice.
Chronic opioid therapy can disrupt sleep, increase risk of sleep disorders
Patients and medical providers should be aware that chronic opioid use can interfere with sleep by reducing sleep efficiency and increasing the risk of sleep-disordered breathing, according to a position statement from the American Academy of Sleep Medicine.
'Short sleep' gene prevents memory deficits associated with sleep deprivation
The UCSF scientists who identified the two known human genes that promote 'natural short sleep' -- nightly sleep that lasts just four to six hours but leaves people feeling well-rested -- have now discovered a third, and it's also the first gene that's ever been shown to prevent the memory deficits that normally accompany sleep deprivation.
Short sleep duration and sleep variability blunt weight loss
High sleep variability and short sleep duration are associated with difficulties in losing weight and body fat.
Nurses have an increased risk of sleep disorders and sleep deprivation
According to preliminary results of a new study, there is a high prevalence of insufficient sleep and symptoms of common sleep disorders among medical center nurses.
Common sleep myths compromise good sleep and health
People often say they can get by on five or fewer hours of sleep, that snoring is harmless, and that having a drink helps you to fall asleep.
Sleep tight! Researchers identify the beneficial role of sleep
Why do animals sleep? Why do humans 'waste' a third of their lives sleeping?
Does extra sleep on the weekends repay your sleep debt? No, researchers say
Insufficient sleep and untreated sleep disorders put people at increased risk for metabolic problems, including obesity and diabetes.
Kicking, yelling during sleep? Study finds risk factors for violent sleep disorder
Taking antidepressants for depression, having post-traumatic stress disorder or anxiety diagnosed by a doctor are risk factors for a disruptive and sometimes violent sleep disorder called rapid eye movement (REM) sleep behavior disorder, according to a study published in the Dec.
More Sleep News and Sleep Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.