Muscat: A study from the University of Science and Technology of China, the Kunming Institute of Zoology of the Chinese Academy of Sciences, and the Hefei University of Technology has revealed that exposure to artificial light at night can lead to depression-like behaviors by activating a specific neural pathway in the brain.

According to Oman News Agency, the study was conducted on a group of hedgehogs, diurnal mammals closely related to primates, providing insight into how nighttime light can disrupt mood regulation. The research team exposed hedgehogs to blue light for two hours each night for three weeks. Following this exposure, the animals displayed clear depression-like symptoms, including a 20 percent decrease in sucrose preference, reduced exploratory behavior, and impaired long-term memory.

Utilizing advanced neural tracing techniques, the researchers discovered a previously unidentified visual circuit. They observed specialized retinal neurons sending direct signals to the periaqueductal nucleus, which then connects to the nucleus accumbens, a crucial brain center for mood regulation. When the periaqueductal nucleus neurons were chemically silenced, hedgehogs did not develop depression-like behaviors in response to nighttime light exposure. Further analysis through RNA sequencing revealed these changes coincided with altered activity in genes associated with depression, suggesting potential long-term effects.

“These findings provide us with both a warning and a roadmap,” said Yao Yonggang, professor at the Kunming Institute of Zoology. The same light that enables us to be productive at night may be subtly reshaping the brain circuits that control mood-but now we know where to look for solutions, he added.