summary: A new study reveals how non-REM sleep improves cognitive performance by synchronizing neural activity and improving information encoding. Researchers observed the brain activity of macaque monkeys during visual tasks before and after sleep and found that neuronal desynchronization after non-REM sleep led to improved task performance.
Brain stimulation, such as simulated sleep, mimics these effects and has shown the potential for treatments to boost cognition without actual sleep. The findings suggest that sleep reshapes excitatory and inhibitory brain connections, paving the way for innovations in treating sleep disorders and improving cognitive performance.
important facts:
- Non-REM sleep synchronizes neural activity and increases post-sleep cognitive ability.
- Simulated low-frequency stimulation mimics the benefits of sleep and increases task accuracy.
- Research suggests a potential treatment to boost cognition without actually sleeping.
sauce: rice university
Although it is well known that sleep enhances cognitive performance, the underlying neural mechanisms, particularly those associated with non-rapid eye movement (NREM) sleep, remain largely unknown.
A new study by a team of researchers from Rice University, Houston Methodist Center for Neural System Repair, and Weill Cornell Medical College, coordinated by Rice University’s Valentin Dragoy, shows that sleep improves neuronal and behavioral performance. We have uncovered an important mechanism that has the potential to change fundamental human functioning. Understand how sleep increases brain power.
This research scienceHere we reveal how non-REM sleep (the light sleep you experience while napping, for example) promotes brain synchronization and enhances the encoding of information, shedding new light on this sleep stage. I’m doing it.
The researchers reproduced these effects through invasive stimulation, suggesting promising possibilities for future neuromodulatory therapies in humans. The implications of this discovery could pave the way for innovative treatments for sleep disorders, as well as ways to improve cognitive and behavioral performance.
The study involved examining neural activity in multiple brain regions of macaque monkeys while performing a visual discrimination task before and after 30 minutes of non-REM sleep in macaques.
The researchers used a multi-electrode array to record the activity of thousands of neurons across three brain regions associated with visual processing and executive functions: the primary and middle visual cortices, and the dorsolateral prefrontal cortex.
To confirm that macaques are in a state of non-REM sleep, researchers used polysomnography to monitor their brain and muscle activity, as well as video analysis to determine when the macaques closed their eyes and their bodies relaxed. I confirmed that it was.
The results of this study demonstrated that sleep improved the animals’ performance on a visual task and improved their accuracy in distinguishing rotated images. Importantly, this improvement was specific to monkeys that actually fell asleep, and macaques that did not fall asleep but experienced quiet awakenings did not show similar performance improvements.
“During sleep, we observed increased low-frequency delta wave activity and synchronization of firing between neurons across different cortical regions,” said lead author, former research fellow in Dragoi’s lab and current resident in neurosurgery at Weill Cornell University. said Dr. Natasha Karas.
“However, after sleep, neuronal activity became more desynchronized and neurons were able to fire more independently than before sleep. This change improved the accuracy of information processing and performance on visual tasks. It has improved.”
The researchers also simulated the neural effects of sleep through low-frequency electrical stimulation of the visual cortex. They applied 4 Hz stimulation to mimic the delta frequency observed during non-REM sleep while the animals were awake.
This artificial stimulation mimicked the desynchronization effect seen after sleep and similarly improved the animals’ ability to perform the task. This suggests that specific patterns of electrical stimulation can potentially be used to emulate the cognitive benefits of sleep.
“This finding is important because it suggests that some of the restorative and performance-enhancing effects of sleep may be obtained without the need for actual sleep,” said study co-author Rice. said Dragoi, a professor of electrical and computer engineering at the university. Daniel J. Harrison III is the President’s Distinguished Chair in Neuroprosthetics at Houston Methodist University and Professor of Neuroscience at Weill Cornell University.
“The ability to recreate sleep-like neural desynchronization in the awake state is a novel way to improve cognitive and perceptual performance in situations where sleep is not possible, such as in people with sleep disorders or in extenuating circumstances such as space exploration.” It opens up new possibilities.”
The researchers built a large-scale neural network model to further investigate their results. They found that during sleep, both excitatory and inhibitory connections in the brain weaken, but this happens asymmetrically, with inhibitory connections being weaker than excitatory connections, which leads to increased excitation. I discovered that it causes
“We discovered a surprising solution that the brain employs after sleep, whereby neural populations participating in a task become synchronized after sleep, even though they receive synchronized input during sleep.” The level will drop,” Dragoi said.
The idea that NREM sleep effectively ‘boosts’ the brain in this way, and that this reset can be artificially mimicked, raises the possibility of developing therapeutic brain stimulation techniques to improve cognitive function and memory. .
“Our study not only advances the mechanistic understanding of the role of sleep in cognitive function, but also shows that specific patterns of brain stimulation can substitute for some of the benefits of sleep, independent of sleep itself. “We have broken new ground by showing the future potential of increasing brain function by using this method,” Dragoi said.
Funding: This research was supported by National Eye Institute grants 5R01EY026156 (VD) and 5F31EY029993 (NK).
About this sleep and cognition research news
author: alex becker
sauce: rice university
contact: Alex Becker – Rice University
image: Image credited to Neuroscience News
Original research: Closed access.
“NREM sleep improves behavioral performance by desynchronizing cortical circuits” by Valentin Dragoi et al. science
abstract
NREM sleep improves behavioral performance by desynchronizing cortical circuits
Sleep improves cognitive performance, but little is known about the neural mechanisms underlying this improvement.
We performed multielectrode recordings in the visual and dorsolateral prefrontal cortex of macaques while the animals performed a visual discrimination task before and after non-rapid eye movement (NREM) sleep.
Although sleep induces synchronous fluctuations in population activity across cortical areas, post-sleep population activity became more asynchronous compared to the pre-sleep state.
Post-sleep changes correlated with increased information encoded in population activity in each region and improved behavioral performance.
Electrical stimulation of the visual cortex at 4 Hz emulated the beneficial effects of sleep on networks and perceptual performance.
Large-scale neural network models showed that asymmetric inhibition of local intracortical synapses is consistent with observed changes in neural activity after sleep.
