13th February, 2018: In groundbreaking research
neuroscientists of Michigan State University, USA have discovered how spending
too much time in dimly lit rooms and offices would change the brain’s structure
and hurt one’s ability to remember and learn. The findings are published in the
The study was conducted on the brains of Nile grass rats (which, like humans, are diurnal and sleep at night). It was found that the rats exposed to dim light lost about 30 percent of capacity in the hippocampus, a critical brain region for learning and memory, and performed poorly on a spatial task they had trained on previously. The rats exposed to bright light, on the other hand, showed significant improvement on the spatial task.
“When we exposed the rats to dim light, mimicking the cloudy days of Midwestern winters or typical indoor lighting, the animals showed impairments in spatial learning,” said Antonio Nunez, co-author of the study. “This is similar to when people can’t find their way back to their cars in a busy parking lot after spending a few hours in a shopping mall or movie theatre.”
The research also identified the reason for such reduction in cognitive functions. Sustained exposure to dim light is found to lead to significant reductions in a substance called brain derived neurotrophic factor (BDNF), a peptide that helps maintain healthy connections and neurons in the hippocampus. It also causes reduction dendritic spines, or the connections that allow neurons to “talk” to one another.
“Since there are fewer connections being made, this results in diminished learning and memory performance that is dependent upon the hippocampus,” Soler, another co-author said. “In other words, dim lights are producing dimwits.”