Lack of sleep may lead to loss of brain cells
Lack of adequate sleep may lead to much more serious problems than previously thought. We like to think that we can catch up on a sleep deficit without any residual problems and move on with our lives with a totally refreshed feeling after a good nights sleep. However, new research has found this may not be true. In fact too much loss of sleep may actually lead to serious damage in the brain.
In our modern society a shortening of sleep times is often anticipated, even though the long-term consequences of extended wakefulness on the brain are not well understood, reports The Journal of Neuroscience. Researchers have found that locus ceruleus neurons (LCns) are metabolically active neurons which fire at increased rates when there is sustained wakefulness. LCns are essential for optimal alertness. Researchers hypothesized that wakefulness is a metabolic stressor for LCns and that with long periods of wakefulness adaptive mitochondrial metabolic responses fail and injury follows.
Most people are well aware that not getting enough sleep causes an impairment of cognitive performance, reports The University of Pennsylvania School of Medicine. Chronically sleep-deprived people, such as shift workers, students, and truckers, have a common strategy to simply to catch up on missed sleep on the weekends. What is considered common wisdom generally leads people to believe that you can catch up your sleep without any lasting negative effects.
However, in a new study from the University of Pennsylvania School of Medicine disturbing evidence has emerged that chronic sleep loss may be more serious than previously thought and may actually lead to irreversible physical damage to and loss of brain cells, as covered in the publication of this research in The Journal of Neuroscience.
Sigrid Veasey, MD, an associate professor of Medicine and a member of the Center for Sleep and Circadian Neurobiology at the University of Pennsylvania School of Medicine, along with collaborators from Peking University, used a mouse model of chronic sleep loss. These researchers have determined that extended wakefulness is associated with injury to, and loss of, neurons that are essential for alertness and optimal cognition, which are the locus coeruleus (LC) neurons.
Veasey has said, "In general, we’ve always assumed full recovery of cognition following short- and long-term sleep loss. 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 a consideration of possible lasting injury in the brain." Veasey and his associates wanted to determine exactly whether chronic sleep loss injures neurons, whether or not the injury is reversible, and exactly which neurons are involved.
The researchers examined mice following periods of normal rest, short wakefulness, or extended wakefulness, which modeled a shift worker's typical sleep pattern. It was observed that after several days of shift worker sleep patterns, LC neurons in the mice began to display increased cell death. Veasey noted that this is the first report that sleep loss can actually result in a loss of neurons. This study also demonstrated the significance of sleep for restoring metabolic homeostasis in mitochondria in the LC neurons and possibly other important brain areas, in order to ensure their optimal functioning during waking hours.
It has been stressed by Veasey that more work must be done to establish whether a similar phenomenon happens in people and to determine what durations of wakefulness may leave individuals at risk of neural injury. The adaptive response to sleep loss may be different in people with various conditions, such as:
1: Aging people