Those of us who sleep longer on weekends to try to make up for the time we didn't get enough sleep during the week may actually be losing some brain cells.
According to University of Pennsylvania neuroscientist Sigrid Veasey, the common idea that the 'sleep debt' can be replenished by getting extra sleep days later may be a myth.
After putting a bunch of laboratory mice on a schedule similar to one people doing shift work experience, Veasey and her team discovered that the mice brains lost up to 25 percent of the neurons associated with alertness and cognitive functioning.
Writing in the Journal of Neuroscience, she explains that when mice lose a little sleep, their brains respond by creating more of a protein called sirtuin type 3, which energizes and protects the neurons. But when the loss of sleep became habitual, release of the protein stopped and depletion of neurons accelerated.
Veasey and her group now plan to study the brains of deceased shift workers to see whether the same damage can be detected in humans.