Feeling sleepy after a sleepless night?

In many cases, people spend sleepless night. Especially, if we consider the case of students during exam time. Many of the students have a habit of studying throughout the night prior to exams and then they feel sleepy while writing them. Have you not experienced during your student life? And in some cases you may also get a feedback from them that even though he studied he was not able to recollect it during the exams. And I am sure it must have been the case with you as well at some stage in your life. 

Have you wondered why is it so? 

A recent study published in Nature has answers to these questions?

A recent study on rats have suggested that sleep deprived neurons may shut down even when awake. As a result, sleep-deprived selves are so cognitively challenged: we are, if not precisely half-asleep, partially asleep.

“After a long period in an awake state, cortical neurons can go briefly ‘offline,’” wrote researchers led by University of Wisconsin neuroscientists Vladyslav Vyazovskiy and Giulio Tononi in a study published April 27 in Nature. “Although both EEG and behavior indicate wakefulness, local populations of neurons in the cortex may be falling asleep, with negative consequences for performance.” To study rats’ neurology, Tononi’s team wired their brains to an EEG machine, kept them awake longer than usual, and looked for patterns in readouts of their brains’ electrical activity.

They found that scattered neurons throughout the rats’ brains gradually alternated between periods of activity and inactivity — a pattern associated with deep sleep, not wakefulness. But unlike their synchronization during sleep, these oscillations were brief and disjointed.When the researchers tested the rats in a sugar-pellet-reaching task, performance declined in proportion to their neurons’ “offline” status, suggestive of how sleep-deprived people have trouble functioning.

Sleepwalkers, for example, seem to inhabit “a twilight state between sleep and wakefulness,” wrote Colwell. Many animals also alternate between shutting down their brains’ left and right hemispheres, allowing for rest while maintaining vigilance.“These observations also suggest that single neurons can move into a rest state,” wrote Colwell. 

“The ability to control behavior actively with some neural circuits while others may be idling could be evolutionarily advantageous.” However, Colwell cautioned against assuming that the patterns seen by Tononi in rats are responsible for short-of-sleep human grouchiness, distraction and poor judgment. For now that’s “arguably an intellectual stretch,” he wrote — but the the data supports further investigations. “And although it is only anecdotal evidence,” Colwell concluded, “I could swear that some of my students can sleep with their eyes wide open.”

 I am sure that after reading this article, many students would avoid spending sleepless nights during exams.

Source:  University of California, Los Angeles