Nav: Home

When you're tired, your brain cells actually slow down

November 08, 2017

It has been established that sleep deprivation slows down our reaction time, but it has been unclear exactly how the lack of sleep affects brain activity and subsequent behavior.

A new Tel Aviv University study published in Nature Medicine finds that individual neurons themselves slow down when we are sleep deprived, leading to delayed behavioral responses to events taking place around us. The neural lapse, or slowdown, affects the brain's visual perception and memory associations.

The study was an international collaboration led by Dr. Yuval Nir of TAU's Sackler Faculty of Medicine and Sagol School of Neuroscience; Prof. Itzhak Fried of UCLA, TAU and Tel Aviv Medical Center; and sleep experts Profs. Chiara Cirelli and Giulio Tononi at the University of Wisconsin-Madison.

"When a cat jumps into the path of our car at night, the very process of seeing the cat slows us down. We're therefore slow to hit the brakes, even when we're wide awake," says Dr. Nir. "When we're sleep-deprived, a local intrusion of sleep-like waves disrupts normal brain activity while we're performing tasks."

Investigators recorded the brain activity of 12 epilepsy patients who had previously shown no or little response to drug interventions at UCLA. The patients were hospitalized for a week and implanted with electrodes to pinpoint the place in the brain where their seizures originated. During their hospitalization, their neuron activity was continuously recorded.

After being kept awake all night to accelerate their medical diagnosis, the patients were presented with images of famous people and places, which they were asked to identify as quickly as possible.

"Performing this task is difficult when we're tired and especially after pulling an all-nighter," says Dr. Nir. "The data gleaned from the experiment afforded us a unique glimpse into the inner workings of the human brain. It revealed that sleepiness slows down the responses of individual neurons, leading to behavioral lapses."

In over 30 image experiments, the research team recorded the electrical activity of nearly 1,500 neurons, 150 of which clearly responded to the images. The scientists examined how the responses of individual neurons in the temporal lobe -- the region associated with visual perception and memory -- changed when sleep-deprived subjects were slow to respond to a task.

"During such behavioral lapses, the neurons gave way to neuronal lapses -- slow, weak and sluggish responses," says Prof. Fried. "These lapses were occurring when the patients were staring at the images before them, and while neurons in other regions of the brain were functioning as usual."

Investigators then examined the dominant brain rhythms in the same circuits by studying the local electrical fields measured during lapses. "We found that neuronal lapses co-occurred with slow brain waves in the same regions," Dr. Nir says. "As the pressure for sleep mounted, specific regions 'caught some sleep' locally. Most of the brain was up and running, but temporal lobe neurons happened to be in slumber, and lapses subsequently followed.

"Since drowsy driving can be as dangerous as drunk driving, we hope to one day translate these results into a practical way of measuring drowsiness in tired individuals before they pose a threat to anyone or anything," Dr. Nir concludes.
-end-
The paper's other co-authors were Thomas Andrillon of the Ecole Normale Superieure in Paris, Amit Marmelshtein of Tel Aviv University, and Nanthia Suthana of UCLA.

American Friends of Tel Aviv University (AFTAU) supports Israel's most influential, comprehensive and sought-after center of higher learning, Tel Aviv University (TAU). TAU is recognized and celebrated internationally for creating an innovative, entrepreneurial culture on campus that generates inventions, startups and economic development in Israel. For three years in a row, TAU ranked 9th in the world, and first in Israel, for alumni going on to become successful entrepreneurs backed by significant venture capital, a ranking that surpassed several Ivy League universities. To date, 2,400 patents have been filed out of the University, making TAU 29th in the world for patents among academic institutions.

American Friends of Tel Aviv University

Related Neurons Articles:

Paying attention to the neurons behind our alertness
The neurons of layer 6 - the deepest layer of the cortex - were examined by researchers from the Okinawa Institute of Science and Technology Graduate University to uncover how they react to sensory stimulation in different behavioral states.
Trying to listen to the signal from neurons
Toyohashi University of Technology has developed a coaxial cable-inspired needle-electrode.
A mechanical way to stimulate neurons
Magnetic nanodiscs can be activated by an external magnetic field, providing a research tool for studying neural responses.
Extraordinary regeneration of neurons in zebrafish
Biologists from the University of Bayreuth have discovered a uniquely rapid form of regeneration in injured neurons and their function in the central nervous system of zebrafish.
Dopamine neurons mull over your options
Researchers at the University of Tsukuba have found that dopamine neurons in the brain can represent the decision-making process when making economic choices.
Neurons thrive even when malnourished
When animal, insect or human embryos grow in a malnourished environment, their developing nervous systems get first pick of any available nutrients so that new neurons can be made.
The first 3D map of the heart's neurons
An interdisciplinary research team establishes a new technological pipeline to build a 3D map of the neurons in the heart, revealing foundational insight into their role in heart attacks and other cardiac conditions.
Mapping the neurons of the rat heart in 3D
A team of researchers has developed a virtual 3D heart, digitally showcasing the heart's unique network of neurons for the first time.
How to put neurons into cages
Football-shaped microscale cages have been created using special laser technologies.
A molecule that directs neurons
A research team coordinated by the University of Trento studied a mass of brain cells, the habenula, linked to disorders like autism, schizophrenia and depression.
More Neurons News and Neurons 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: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.