Researcher Vladyslav Vyazovskiy from the University of Wisconsin-Madison studied the brains of sleep-deprived rats and found that individual neurons can effectively fall asleep, even though some others are awake.
This means that even though rats may be awake, some parts of their brain may be actually switching off to take rest.
During the study, Vyazovskiy kept rats awake well past their bedtime and used sensors to evaluate the activity of individual neurons. The sensors depicted a powerful "slow-wave"signal akin to what is present in humans who are getting less sleep.
But what seemed abnormal was that some of the neurons simply stopped working or they had switched off. Neurons in some part of the brain switched off even while some others stayed on.
This research provides the reason why sleep deprivation can cause memory lapses, irritation, and poor judgement.