A new Penn Medicine study suggests that chronic sleep loss may cause brain damage. Chronic sleep loss may be more serious than previously thought and may even lead to irreversible physical damage to and loss of brain cells.åÊThe research is published today in The Journal of Neuroscience. Sigrid Veasey, MD , associate professor of Medicine and a member of the Center for Sleep and Circadian Neurobiology at the Perelman School of Medicine and collaborators from Peking University, determined that extended wakefulness is linked to injury to, and loss of, neurons that are essential for alertness and optimal cognition. For you scientists, these neurons are called the locus coeruleus (LC) neurons. “In general, we‰Ûªve always assumed full recovery of cognition following short- and long-term sleep loss,” Veasey says.åÊ”But some of the research in humans has shown that attention span and several other aspects of cognition may not normalize even with three days of recovery sleep, raising the question of lasting injury in the brain.” Mice were examined following periods of normal rest, short wakefulness, or extended wakefulness, modeling a shift worker’s typical sleep pattern. The findings suggest that mitochondria in LC neurons respond to sleep loss and can adapt to short-term sleep loss but not to extended wake. Veasey stresses that more work needs to be done to establish whether a similar phenomenon occurs in humans and to determine what durations of wakefulness place individuals at risk of neural injury. The study provides another confirmation of a rapidly growing scientific consensus:åÊ sleep is more important than was previously believed.