Gene that makes us sleepy when we are sick identified

Scientists, including one of Indian origin, have identified a gene that makes a person sleepy when they are sick.

Researchers from the University of Pennsylvania in the US found that a single gene, called nemuri, fights germs with its inherent antimicrobial activity and drives prolonged, deep sleep after an infection.

"While it's a common notion that sleep and healing are tightly related, our study directly links sleep to the immune system and provides a potential explanation for how sleep increases during sickness," said Amita Sehgal, a professor at University of Pennsylvania.

Without the nemuri gene, flies were more easily aroused during daily sleep, and their acute need for an increase in sleep -- induced by sleep deprivation or infection -- was reduced.

On the other hand, sleep deprivation, which increases the need for sleep, and to some extent infection, stimulated nemuri to be expressed in a small set of fly neurons nestled close to a known sleep-promoting structure in the brain.

Overexpression of nemuri increased sleep in bacteria-infected flies and led to their increased survival compared to non-infected control flies, according to a study published in the journal Science.

In response to infection, nemuri appears to kill microbes, most likely in the peripheral parts of the fruit fly body, and increases sleep through its action in the brain.