Nature Subs: Chinese scientists find that blue light at night causes depression! Electronic sons are best put away!

June 4, 2020 /
BiovalleyBIOON / -- A team of researchers from several Chinese institutions (China University of Science and Technology, Hefei University, Kunming Institute of Zoology of the Chinese Academy of Sciences, Anhui Medical University, etc.) found that repeated exposure of laboratory mice to blue light at night can lead to the emergence ofdepressionIn their paper, published in the journal Nature Neuroscience, the team described experiments they conducted with laboratory mice and blue light, and what their results might mean for humansin addition to producing vision, light regulates a variety of physiological functions, including emotionsLight therapy used during the day is known to have antidepressant effects, but excessive light at night is reported to be associated withsymptoms of depressionPrevious studies have shown that people who work night shifts are more likely to suffer from depressionthan those who work day shifts, but the cause is unclearRecent studies have shown that regular use of your smartphone at night can also lead to depressionimage source: Nature NeuroscienceIn this new study, researchers want to know if the light felt in the eye at night is also part of the problem -- or if in this case, it's just blue light that has an effectTo learn more about the more details and related mechanisms, the researchers conducted experiments to expose lab mice to blue lightthe researchers exposed the mice to blue light for two hours each night for three weeks, and then looked closely at the mice to determine whether blue light had a significant effect on their behaviorAt first, the mice showed no signs of change, the researchers found But three weeks later, the mice began to work less hard to get the sugar reward, and less desperate to escape when it was possible to escape -- both of which were thought to be signs of depression in the mice The researchers also found that depression symptoms last for up to three weeks, even after the night lights are stopped to understand why sending blue light to mice causes depression, the researchers studied the brains of mice -- especially the neural pathways from the eyes to the brain They found a special light receptor in the retina of mice that leads to mood-related areas of the brain: nucleus and dorsal perihabenular nucleus When the researchers disconnected them, the mice did not become depressed because they were exposed to blue light at night The researchers also found that these pathways became more active at night when exposed to blue light than during the day They say this explains why dealing with blue light during the day does not lead to depression overall, in the study, researchers found that nighttime blue light induces depression-like behavior without affecting circadian rhythms Retinal black-optic protein systotic nerve-sectional cells mediate this effect through a neural pathway from the back-to-back nucleus to the volt-separated nucleus Importantly, the back core is controlled by circadian rhythms and is more likely to get excited at night than during the day researchers say this suggests that the ipRGC-dpHb-NAc pathway prioritizes the transmission of light signals at night, thus mediatizing depression-like behavior induced by night lights These findings may be relevant and have significant clinical implications when considering the effects of night lighting on mental health in the industrial world (biovalleybioon.com) Reference: Exposing mice to blue light at night leads to de-dr de-symptoms
Kai An et al.
A circadian rhythm-gated subcortical pathway for nighttime-light-induced de-in-i-am-in-mice, Nature Neuroscience (2020) DOI: 10.1038/s41593-020-0640-8