US scientists discover how time spent in front of a screen disrupts sleep – Xinhua

In this file photo illustration of October 20, 2015, a child read an article about the latest Star Wars movie, "The Force Awakens," on a cell phone in Los Angeles, California. (Xinhua / AFP PHOTO)

WASHINGTON, Nov. 27 (Xinhua) – US researchers have revealed how time spent in front of a screen could disrupt sleep: some cells in the eye, exposed to artificial light late at night, were linked to confusion in the internal clocks.

The study published Tuesday in the journal Cell Reports could help lead to treatments against insomnia, jet lag and migraines. These conditions are also related to cognitive dysfunction, cancer, obesity and metabolic syndrome.

"We are continually exposed to artificial light, whether it's time spent in front of the screen, spending the day indoors or staying awake late at night," said Satchin Panda, a professor at the University of Toronto. Salk Institution, lead author of the study.

"This lifestyle disrupts our circadian rhythms and has deleterious health consequences," said Panda.

The back of our eyes contains a sensory membrane called retina, whose innermost layer contains a tiny population of light-sensitive cells that function as pixels in a digital camera, according to the study.

When these cells are exposed to continuous light, a protein called melanopsin continually regenerates within them, signaling ambient light levels directly to the brain to regulate consciousness, sleep, and alertness.

The protein plays a vital role in the synchronization of our internal clock after 10 minutes of illumination and removes, under the effect of intense light, the hormone melatonin responsible for the regulation of sleep, according to l & # 39; # 39; study.

Salk researchers used molecular tools to activate melanopsin production in mouse retinal cells and found that some of these cells were able to maintain a luminous response when exposed to long light pulses. repeated, while others became numb.

They also discovered that the arrestins, proteins that usually stop the activity of certain receptors, were in fact necessary for melanopsin to continue to respond to prolonged illumination.

In mice lacking arrestin proteins, retinal cells failed to maintain their sensitivity to light under prolonged illumination.

A better understanding of the interactions of melanopsin and how the eyes react to light could be a new target to counter circadian rhythms biased due to the length of the screen.

The Panda team discovered that chemicals called opsinamides could block the activity of melanopsin in mice without affecting their vision, thus providing a potential therapeutic means of treating hypersensitivity to the light undergone by the migraineurs.

The researchers plan to find ways to make melanopsin to reset internal clocks and fight insomnia.