Our brain destroys itself due to a lack of sleep
In general, sleep is very important for the body and mind. Researchers have now found in a mouse experiment that sleep deprivation increases the destructive activity of certain cells in the brain. This leads to an increased risk of developing dementia.
The University of Wisconsin-Madison scientists found in their research that sleep deprivation leads to an increase in the destructive activity of brain cells. This process is designed to destroy normally worn cells. The doctors published the results of their study in the journal "Journal of Neuroscience".
Chronic lack of sleep can lead to Alzheimer's
Deleting potentially harmful debris and worn-out cells and rebuilding the worn circuitry could protect healthy brain connections, the scientists speculate. So this destructive activity can have positive effects in the short term. However, long-term damage can also occur. This could explain why a chronic lack of sleep triggers the risk of Alzheimer's disease and other neurological diseases, explains author Michele Bellesi.
Doctors examine the brains of mice with a lack of sleep
For the study, the research team compared the brains of mice that could either sleep as long as they wanted or were kept awake for eight hours before sleeping. Another group of mice was kept awake for a period of five days, which should mimic a chronic lack of sleep, the scientists explain.
How does sleep deprivation work?
The doctors looked specifically at the so-called glial cells of the brain. Earlier research had found that a gene that regulates the activity of these cells is more active after a period of sleep deprivation. After undisturbed sleep, certain glial cells (astrocytes) appeared to be active in about six percent of the synapses in the brain, say the doctors. In mice with sleep deprivation, the astrocytes appeared to be much more active. In the mice with a delayed sleep of eight hours, the activity of the astrocytes in the synapses was eight percent. Animals with chronic sleep deprivation showed increased activity in 13.5 percent of their synapses, the authors add.
Astrocytes literally devour our brains through sleep deprivation
The results suggest that sleep loss can cause astrocytes to destroy an increased number of connections in the brain. We were able to show for the first time that parts of synapses are literally consumed by astrocytes because of the loss of sleep that occurs, explains Bellesi. The finding could explain why a lack of sleep can make people more susceptible to developing dementia.
Deprivation of sleep makes cells associated with brain disorders more active
The team of scientists also found that so-called microglial cells were more active after chronic sleep deprivation. This is a worrying finding because excessive microglial cell activity is linked to a number of brain disorders, Bellesi explains.
More research is needed
We already know that sustained activation of the microglial cells has been observed in Alzheimer's and other forms of neurodegeneration, the scientists say. The results of the current study could explain why a lack of sleep can make people more susceptible to the development of dementia, the researchers continue. Additional research is now needed to better understand the positive and negative effects of sleep. (as)