Chinese researchers on Monday said they have found that exposure to excessive light at night may affect neural circuit in the brain and cause depression.
According to the study recently published by the journal Nature Neuroscience online, light can act on mammals’ physiological functions including mood.
Previous studies have shown that prolonged exposure to abnormal light at night can cause depression and cognitive impairment in human beings, but the mechanism behind the process remained unclear.
Researchers at the University of Science and Technology of China and Hefei University designed an experiment in which they exposed mice to blue light for two hours every night over three weeks.
The mice showed depressive behaviour that lasted even after the blue light was withdrawn.
Using a neural tracing tool, the team found a specific neural circuit affected by blue light, revealing the mechanism behind depression.
If light acts on the same neural circuit in the human body, it may explain how excess exposure to illumination at night affects human beings, said Zhao Huan of Hefei University, one of the authors of the study.