Sleep is thought to reflect neuronal activity. Therefore, to understand the whole sleep wake cycle, even to solve the mystery of sleep, all start with neurons. But now, this direction may need to be adjusted. In a new study published in current biology on September 25, Beijing time, the research team from Washington State University showed that astrocytes are part of sleep homeostasis, and their regulation on sleep may be as important as neurons. < / P > < p > this study opens up a new puzzle for the final solution to the puzzle of why we sleep and how sleep works in the brain, and lays the foundation for potential therapeutic strategies for sleep disorders, nervous system diseases and other sleep related diseases in the future. Ashley ingiosi, the lead author of the study and a postdoctoral researcher in the Department of biomedicine at Elson Freud School of medicine, explained: “our understanding of sleep is mainly based on neurons, which communicate through electrical signals that are easily captured by electroencephalogram (EEG). Astrocytes are glial cells that interact with nerve cells. Instead of using electrical signals, astrocytes use a process called calcium signaling to control their activity < / P > < p > researchers said that for a long time, astrocytes were thought to have five times the number of neurons, but only played a supporting role, rather than directly involved in behaviors and processes. In recent years, neuroscientists have only begun to examine their potential role in various processes. Although some studies have suggested that astrocytes may play a role in sleep, only recently have reliable scientific tools been available to study their calcium activity. < / P > < p > to further study the role of astrocytes in sleep, the team used a rodent model to record the calcium activity of astrocytes during sleep and wakefulness and after sleep deprivation. < / P > < p > they used a fluorescent calcium indicator, which was imaged through a miniature head mounted microscope, and they looked directly at the brains of mice as they moved around and showed normal behavior. < / P > < p > the researchers observed that, during sleep and wakefulness, calcium activated fluorescent calcium flickered in astrocytes (see video below). The unique method they used was the first to study the calcium activity of astrocytes during sleep in behavior free animals. < / P > < p > by looking at astrocytes in the brain region (frontal cortex) associated with measurable EEG changes in sleep needs, researchers found that their activity was dynamically changing throughout the sleep wake cycle, as were neurons. They also observed that calcium activity was highest when sleep demand was greatest, and lowest at the end of the test period, when sleep needs disappeared. < p > < p > next, they kept the mice awake for the first six hours of normal rest and observed changes in calcium activity and slow wave activity in electroencephalogram during sleep, a key indicator of sleep demand. They found that lack of sleep led to increased calcium activity in astrocytes, which decreased when mice were allowed to sleep. < / P > < p > to find out, they studied mice that selectively lacked a protein called STIM1 in astrocytes, which reduced the amount of available calcium. After being deprived of sleep, the sleep time and sleepiness of mice were not as good as those of normal mice, which further confirmed the previous findings that astrocytes play an important role in regulating sleep demand. < / P > < p > finally, they tested the hypothesis that the calcium activity of astrocytes might only reflect the electrical activity of neurons. Studies have shown that neuronal electrical activities become more synchronized during non REM sleep and after sleep deprivation, but the situation of astrocytes is opposite to that of neurons. During non REM sleep and after sleep deprivation, the synchronization of astrocytes decreases. “This shows us that astrocytes are not passively following neurons,” ingiosi said. Since astrocytes do not necessarily exhibit the same activity pattern as neurons, this may actually suggest that they play a more direct role in regulating sleep and sleep needs. Of course, more research is needed to further elucidate the role of astrocytes in sleep and sleep regulation < p > < p > ingiosi plans to study the calcium activity of astrocytes in other areas of the brain that have been shown to be important for sleep and wakefulness. In addition, she would like to observe the interaction between astrocytes and different neurotransmitters in the brain to tease out the mechanisms by which astrocytes drive sleep and sleep needs. “For more than 100 years, we may have been looking in the wrong places,” said Marcos frank, a biomedical professor and author of the study. This study provides strong evidence that we should target astrocytes to understand why and how we sleep, and to develop therapies that can help sleep disorders and other health conditions associated with sleep disorders. ” The release and download schedule of Microsoft Flight Simulation varies from region to region