Light at night ‘can put you in dark mood’

Washington: A new study has shown that exposure to even dim light at night is enough to cause physical changes in the brains of hamsters that may be linked to depression.

Scientists found that female Siberian hamsters exposed to dim light every night for eight weeks showed significant changes in a part of the brain called the hippocampus. This is the first time researchers have found that light at night, by itself, may be linked to changes in the hippocampus. These alterations may be a key reason why the researchers also found that the hamsters exposed to dim light at night showed more depressive symptoms when compared to hamsters in a standard light-dark cycle. "Even dim light at night is sufficient to provoke depressive-like behaviors in hamsters, which may be explained by the changes we saw in their brains after eight weeks of exposure," said Tracy Bedrosian, co-author of the study and doctoral student in neuroscience at Ohio State University. The results were presented in San Diego at the annual meeting of the Society for Neuroscience.