A new animal study suggests that missing out on sleep may cause the brain to stop producing new brain cells while at the same time raising the stress hormone, corticosterone. The research also demonstrated that it is the increase in the stress hormone which causes this effect.
The research was conducted at Princeton University and was published in the Proceedings of the National Academy of Science.
The study was conducted on rats and found a lack of sleep affected the hippocampus, a brain region involved in forming memories. The researchers compared animals who were deprived of sleep for 72 hours with others who were not. They found those who missed out on rest had higher levels of the stress hormone corticosterone and also produced significantly fewer new brain cells in a particular region of the hippocampus.
When the animals’ corticosterone levels were kept at a constant level, the reduction in cell proliferation was abolished.
It is not known how generalizable these effects are to humans, since humans’ brains are more complex and rarely do humans go without sleep for 72 hours at a time. The study does suggest that the lack of sleep, even for shorter intervals, could have a negative effect on the brain.
The results suggest that elevated stress hormone levels resulting from sleep deprivation could explain the reduction in cell production in the adult brain.
Sleep patterns were restored to normal within a week. But levels of brain nerve cell production took twice as long, and were not restored for two weeks. The study showed that the brain appears to boost its efforts in order to counteract the shortage.
The research team was led by Dr Elizabeth Gould, who said that although the role of nerve cell production in adults remained unknown, “the suppression of adult neurogenesis may underlie some of the cognitive deficits associated with prolonged sleep deprivation.”
People who experience a lack of sleep experience concentration problems and other difficulties.