Researchers 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 are significant because the night-time light used in the study was not bright: 5 lux, or the equivalent of having a television on in a darkened room, said Randy Nelson, co-author of the study and professor of neuroscience and psychology at Ohio State. (via.)