If you don't snooze, do you lose? Wake-sleep patterns affect brain synapses

October 9, 2011

An ongoing lack of sleep during adolescence could lead to more than dragging, foggy teens, a University of Wisconsin-Madison study suggests.

Researchers have found that short-term sleep restriction in adolescent mice prevented the balanced growth and depletion of brain synapses, connections between where communication occurs.

"One possible implication of our study is that if you lose too much sleep during adolescence, especially chronically, there may be lasting consequences in terms of the wiring of the brain," says Dr. Chiara Cirelli, associate professor in the department of psychiatry at the School of Medicine and Public Health.

such as schizophrenia tend to start during adolescence but the exact reasons remain unclear. The National Institute of Mental Health funded Cirelli's study; the findings appear in the current issue of Nature Neuroscience.

"Adolescence is a sensitive period of development during which the dramatically," Cirelli says. "There is a massive remodeling of nerve circuits, with many new synapses formed and then eliminated."

Cirelli and colleagues wanted to see how alterations to the sleep-wake cycle affected the anatomy of the developing .

Their earlier molecular and electro-physiological studies showed that during sleep, synapses in adult rodents and flies become weaker and smaller, presumably preparing them for another period of when synapses will strengthen again and become larger in response to ever-changing experiences and learning. They call this the synaptic homeostasis hypothesis of sleep.

Using a two-photon microscope, researchers indirectly followed the growth and retraction of synapses by counting dendritic spines, the elongated structures that contain synapses and thus allow to receive impulses from other brain cells. They compared adolescent mice that for eight to 10 hours were spontaneously awake, allowed to sleep or forced to stay awake.

The live images showed that being asleep or awake made a difference in the dynamic adolescent mouse brain: the overall density of fell during sleep and rose during spontaneous or forced wakefulness.

"These results using acute manipulations of just eight to 10 hours show that the time spent asleep or awake affects how many synapses are being formed or removed in the adolescent brain," Cirelli says. "The important next question is what happens with chronic sleep restriction, a condition that many adolescents are often experiencing."

The experiments are under way, but Cirelli can't predict the outcome. "It could be that the changes are benign, temporary and reversible," she says, "or there could be lasting consequences for brain maturation and functioning."

Explore further: Even in fruit flies, enriched learning drives need for sleep

Related Stories

Even in fruit flies, enriched learning drives need for sleep

June 23, 2011
Just like human teenagers, fruit flies that spend a day buzzing around the "fly mall" with their companions need more sleep. That's because the environment makes their brain circuits grow dense new synapses and they need ...

Brain regions can take short naps during wakefulness, leading to errors

April 27, 2011
If you've ever lost your keys or stuck the milk in the cupboard and the cereal in the refrigerator, you may have been the victim of a tired brain region that was taking a quick nap.

Recommended for you

Zebrafish study reveals clues to healing spinal cord injuries

July 25, 2017
Fresh insights into how zebrafish repair their nerve connections could hold clues to new therapies for people with spinal cord injuries.

Brain stimulation may improve cognitive performance in people with schizophrenia

July 24, 2017
Brain stimulation could be used to treat cognitive deficits frequently associated with schizophrenia, according to a new study from King's College London.

New map may lead to drug development for complex brain disorders, researcher says

July 24, 2017
Just as parents are not the root of all their children's problems, a single gene mutation can't be blamed for complex brain disorders like autism, according to a Keck School of Medicine of USC neuroscientist.

Bird songs provide insight into how developing brain forms memories

July 24, 2017
Researchers at the University of Chicago have demonstrated, for the first time, that a key protein complex in the brain is linked to the ability of young animals to learn behavioral patterns from adults.

Research identifies new brain death pathway in Alzheimer's disease

July 24, 2017
Alzheimer's disease tragically ravages the brains, memories and ultimately, personalities of its victims. Now affecting 5 million Americans, Alzheimer's disease is the sixth leading cause of death in the U.S., and a cure ...

Illuminating neural pathways in the living brain

July 24, 2017
Using light alone, scientists from the Max Planck Institute of Neurobiology in Martinsried are now able to reveal pairs or chains of functionally connected neurons under the microscope. The new optogenetic method, named Optobow, ...

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.