Sub-Journal of "Nature": Sleeping well is too important! Don't let the "repairers" in your brain go on strike

Most people spend a third of their lives doing one thing: sleeping This matter is undoubtedly very important, so scientists have been exploring what benefits sleep brings to the body and brain, and what harm lack of sleep will do to brain health For example, not long ago, we introduced two new studies on why lack of sleep leads to "mental decline" Recently, the University of Rochester Medical A research team of center found for the first time that the immune cells in the brain play an important role in "network repair" during sleep, strengthening the important relationship between sleep and brain health, and helping us understand the relationship between neurodegenerative diseases such as Alzheimer's disease and sleep disorders The research results were published in the journal Nature Neuroscience These important immune cells, called microglia, are the guardians of the brain and spinal cord Once the central nervous system is injured or infected, it will quickly change its shape after receiving the inflammatory signal, take action to eliminate the infection or phagocytosis of dead cells and tissue fragments, and help the brain clear away the garbage "It has long been assumed that the dynamic changes of microglia are less affected by animal behavior." Professor Ania Majewska, who is the principal leader of the study, said: "this study has found that signals in the brain that regulate sleep / wakefulness also act as switches on the immune system." Specifically, the signals the researchers focused on were related to noradrenaline When we fall asleep, the chemical is low in the brain; when norepinephrine increases, it wakes up nerve cells, wakes us up, and makes the brain alert This neurotransmitter not only acts on nerve cells, but also on microglia through special receptors Using advanced in vivo imaging techniques, the researchers observed brain activity in mice They found that when noradrenaline levels are high in the brain, microglia go into a state of dormancy, unable to respond to local damage In addition to repairing the damage, microglia also have an important ability to deal with waking / sleeping conditions Previous work by Professor Majewska and other researchers has found that microglia can fine regulate the connection nodes of neural networks They help maintain the health and function of synapses and prune connections that are no longer needed And the complex neural network wiring and rewiring is an important foundation for us to learn, remember, recognize and move The researchers used dexmedetomidine (DEX), a sedative, to put mice into a state of anesthesia similar to slow wave sleep Sleep quality is closely related to slow wave sleep Compared with the awake state, when the animal is in a sleep like state, microglia are in a highly active "monitoring" state, and soon expand more and more dense processes, which can regulate the peripheral synapses in a larger range Therefore, microglia may be the brain's night repairman "Our work reveals that sleep enhances neural loop remodeling and damage repair, and the ability of some microglia to interact with the brain is one of the reasons." First author Dr rianne Stowell concludes In view of more and more scientific evidence showing that the state of microglia is related to neurodegenerative diseases such as Alzheimer's disease, and other dementia, autism spectrum disorders, schizophrenia are also closely related to the stability of the whole brain neural network, the results of this study suggest that we should pay attention to sleep problems and protect brain health