Mice offer a window into sleep's role in memory

March 24, 2017, Johns Hopkins University
Mice offer a window into sleep's role in memory
Credit: Vittoria Che/Thinkstock

Sleep provides essential support for learning and memory, but scientists do not fully understand how that process works on a molecular level. What happens to synapses, the connections between neurons, during sleep that helps us remember what we learned when awake?

Johns Hopkins neuroscientists believe they have a partial answer. Experimenting with , they found evidence that a process which helps the rodent's waking brain handle its information load also works when the mouse sleeps. The brain, whether in mice or people, learns through strengthening between neurons. But there's an to this strengthening, so to avoid maxing out, the brain must periodically adjust itself through what is called homeostatic scaling-down. This process uniformly weakens the synapses, freeing up capacity for more learning. Because it is consistent across all of the neural network, there is no change in the relative strength of connections, and therefore no degradation of memory.

The scientists found that this scaling process also occurs when mice sleep. During sleep, the brain consolidates memory and enhances its capacity to learn anew when the mouse awakens. Compared to the waking mouse brain, the slumbering brain contains 250 percent more of the protein Homer1a, which, researchers believe, determines when the brain is sufficiently quiet to begin scaling down the strength of synaptic connections.

Explore further: Sleep deprivation handicaps the brain's ability to form new memories, study in mice shows

Related Stories

Sleep deprivation handicaps the brain's ability to form new memories, study in mice shows

February 2, 2017
Studying mice, scientists at Johns Hopkins have fortified evidence that a key purpose of sleep is to recalibrate the brain cells responsible for learning and memory so the animals can "solidify" lessons learned and use them ...

Sleep research high-resolution images show how the brain resets during sleep

February 2, 2017
Striking electron microscope pictures from inside the brains of mice suggest what happens in our own brain every day: Our synapses - the junctions between nerve cells - grow strong and large during the stimulation of daytime, ...

'Recycling protein' shown to affect learning and memory in mice

March 10, 2017
Learning and memory depend on cells' ability to strengthen and weaken circuits in the brain. Now, researchers at Johns Hopkins Medicine report that a protein involved in recycling other cell proteins plays an important role ...

Mouse study shows REM sleep selectively prunes and maintains new synapses

January 27, 2017
(Medical Xpress)—A small team of researchers with affiliations to the New York University School of Medicine and Peking University has found evidence of pruning and maintenance of synapses during REM sleep. In their paper ...

SHY hypothesis explains that sleep is the price we pay for learning

January 9, 2014
Why do animals ranging from fruit flies to humans all need to sleep? After all, sleep disconnects them from their environment, puts them at risk and keeps them from seeking food or mates for large parts of the day.

Brain plasticity: How adult-born neurons get wired-in

February 2, 2017
One goal in neurobiology is to understand how the flow of electrical signals through brain circuits gives rise to perception, action, thought, learning and memories.

Recommended for you

Forty percent of people have a fictional first memory, says study

July 17, 2018
Researchers have conducted one of the largest surveys of people's first memories, finding that nearly 40 per cent of people had a first memory which is fictional.

Protein found to be key component in irregularly excited brain cells

July 17, 2018
In a new study in mice, researchers have identified a key protein involved in the irregular brain cell activity seen in autism spectrum disorders and epilepsy. The protein, p53, is well-known in cancer biology as a tumor ...

Insight without incision: Advances in noninvasive brain imaging offers improvements to epilepsy surgery

July 17, 2018
About a third of epilepsy sufferers require treatment through surgery. To check for severe epilepsy, clinicians use a surgical procedure called electrocorticography (ECoG). An ECoG maps a section of brain tissue to help clinicians ...

New drug target for remyelination in MS is identified

July 17, 2018
Remyelination, the spontaneous regeneration of the fatty insulator in the brain that keeps neurons communicating, has long been seen as crucial to the next big advance in treating multiple sclerosis (MS). However, a lack ...

Artificial neural networks now able to help reveal a brain's structure

July 17, 2018
The function of the brain is based on the connections between nerve cells. In order to map these connections and to create the connectome, the "wiring diagram" of a brain, neurobiologists capture images of the brain with ...

Convergence of synaptic signals is mediated by a protein critical for learning and memory

July 16, 2018
Inside the brain, is a complex symphony of perfectly coordinated signaling. Hundreds of different molecules amplify, modify and carry information from tiny synaptic compartments all the way through the entire length of a ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.