There are more and more studies on how sleep affects our body and especially the brain . Now, research from the David Geffen School of Medicine at the University of Los Angeles, California (USA) and the University of Tel Aviv (Israel) confirms that lack of sleep has a severe impact on how the brain works , with potentially dangerous consequences in everyday life. For the brain, not getting enough rest is like overindulging in alcohol.
“We found that starving – sleep – the brain also deprives neurons of the ability to function properly. This paves the way for cognitive lapses in how we perceive and react to the world around us,” explains Itzhak Fried, leader. from work to the journal Nature Medicine.
“Inactive” neurons communicate inefficiently
The researchers worked with 12 people with epilepsy. All the participants had electrode implants in their brains, with the goal of recording where their epileptic seizures originated in the run-up to surgery.
As part of their evaluation, the seizures were induced by insomnia, keeping them awake all night until they experienced an attack, so that the electrical activity in the brain could be properly recorded.
In the experiment, participants were given a categorization task in which they had to sort different images into different categories as quickly as possible. While performing this task, the researchers focused on electrical activity in the temporal lobe of the brain, which has been associated with memory and visual recognition.
The scientists observed that the more sleepy and tired the participants were, the more difficult the task was and the slower it was to perform.
“We were fascinated by how sleep deprivation dampened the activity of brain cells,” says Yuval Nir, a co-author of the work. Thus, with lack of sleep, brain cells became “sluggish” and neural communication was impaired.
“The neurons responded slowly and their transmissions lasted longer than usual,” says Nir.
Insomnia, therefore, caused the activity of the brains – exhausted by fatigue – to be ‘drowsy’.
They also found that brain cells that took the longest to respond were associated with slower brain waves , such as those normally recorded during sleep phases, and that this slow-motion activity was located in the same regions of the brain.
“Slow waves of sleep disrupted patients ‘brain activity and task performance. This phenomenon suggests that selected regions of the patients’ brains were dozing, causing mental lapses, while the rest of the brain was awake and functioning as usual, “notes Fried.
Researchers compare lack of sleep to heavy drinking, and suggest that more appropriate measures should be taken against tired driving.
“ Inadequate sleep exerts a similar influence on our brain to drinking too much . However, there are no legal or medical standards to identify tired drivers on the road in the same way that we attack drunk drivers,” concludes the scientist.
Reference: Selective neuronal lapses precedes human cognitive lapses following sleep deprivation. Yuval Nir, Thomas Andrillon, Amit Marmelshtein, Nanthia Suthana, Chiara Cirelli, Giulio Tononi & Itzhak Fried. Nature Medicine 2018. doi: 10.1038 / nm.4433
