Certain Brain Nerve Cells “Sleep” for Short Periods of Time in Stages of Wakefulness

This finding, published in the latest issue of Nature, could explain everyday small oversights or negligence, such as losing keys.

Until now, scientists had thought that sleep deprivation usually affect the entire brain. Electroencephalograms (EEGs, for its acronym in English) show typical brain wave patterns of two different states: the waking and sleep.

As explained by Dr. Chiara Cirelli, a professor of psychiatry at the School of Public Health Medicine of this university, “even before you feel tired, there are signs in the brain that should stop doing certain activities that may require a state alert. ” “Specific groups of neurons might be falling asleep, with negative consequences for the actions of the individual,” he says.

“We know that when we are sleepy, make mistakes, our attention is decentralized and guard down,” says Cirelli, who says his team “has been with EEGs, even when you’re awake, you can experience periods of ‘micro sleep, the most likely cause of sleepiness at the wheel.

However, this new research has found that even before these stages, the brain shows similar activity to sleep hurts.

To make this finding, researchers at the University of Wisconsin probes inserted in specific groups of neurons in the brains of freely behaving rats. After the animals were forced to stay awake for extended periods of time and the probes showed areas of ‘local sleep’, although the rats appeared to be awake and active.

“Even when some neurons are disconnected, the general measurement indicated waking EEG of the brain in rats,” says Cirelli, who says that, when prolonged period of wakefulness of these animals, “began to make mistakes.”

When these animals were challenged with a difficult task, like reaching for a ball with a foot of sugar began to drop the ball or not get caught, indicating that some neurons may have been disabled.

“This activity occurs in a few cells,” says Cirelli, who adds that, for example, “of 20 neurons monitored in an experiment, 18 remained awake.” “In the other two periods there were signs of ’short naps’ of activity alternating with periods of silence.

The researchers only tested motor tasks, so they concluded that the neurons affected by ‘naps’ are in the cortex.