If you’ve been skipping sleep, thinking you’ll make up for it on weekends, here’s some bad news. Scientists at the University of Pennsylvania and Peking University have found that chronic sleep loss may actually lead to irreversible damage to and loss of brain cells.
“We live in a society where each year high school teens, college kids, and young adults stay up later and later and later because of increased demands on their time and to have that edge in the world," says Dr. Sigrid Veasey, associate professor of medicine and a member of the Center for Sleep and Circadian Neurobiology at the Perelman School of Medicine. "But what if that edge is lost through brain injury?”
Researchers monitored the brains of mice after periods of normal rest, short wakefulness, or extended wakefulness, similar to the sleep patterns of a typical shift worker, like a truck driver. For the first time, they found that after several days of shift-worker style sleep patterns, mice lost 25 percent of a particular kind of neuron essential for alertness and optimal cognition, and experienced a reduction in a particular enzyme that regulates proteins involved in increasing energy production, and protects neurons from free radicals.
Though the study looked at the brains of mice, all studied mammals contain those same neurons. “We cannot extrapolate how much damage humans would have for the same sleep loss, but it seems quite likely that given enough sleep loss chronically, we would see some damage to these neurons,” Veasey says.
For Veasey, the next step is to use imaging techniques to study people who work night shifts to see if they can determine differences in brain activation, neurotransmission, and metabolites. “We would love to come up with a simple biomarker so that individuals could track their own status/sleep needs.”