Sleep is a necessity, as well as a pleasure, and poor quality sleep can have long-term negative health consequences and influence our daily activities, since if we don’t get a good night’s rest the next day we feel tired and we It’s harder to concentrate.
Now, however, new animal research suggests that little-studied brain cells called astrocytes play a key role in controlling the need for sleep and could one day help humans sleep less without experiencing mental fatigue. and without deteriorating health.
The results of the study have been published in The Journal of Neuroscience and have shown that activation of these cells kept mice awake for hours when they would normally be resting, and also without making them drowsier as a result.
Upon activation of the astrocytes, the mice remained awake for six hours or more during their normal sleep period, and no subsequent changes in sleep time or intensity were observed in response to additional wakefulness.
“Prolonged wakefulness normally increases sleep time and intensity, but what we saw in this study was that despite the hours of additional wakefulness, these mice did not differ from well-rested controls in terms of how long and with how hard they slept,” explained lead author Marcos Frank, a neuroscientist and professor at Washington State University (WSU) Elson S. Floyd School of Medicine. “This opens up the possibility that one day we may have interventions that could target astrocytes to mitigate the negative consequences of prolonged wakefulness.”
Improve the productivity and health of shift workers
Frank envisioned it could include drugs that could be used to improve the productivity, safety, and health of shift workers and others who work long or unusual hours, such as first responders and the military. Sleep loss and irregular sleep schedules have been shown to influence a variety of key processes, including attention, cognition, learning, memory, metabolism, and immune function.
Astrocytes are non-neuronal cell types that interact with neurons, which are the brain cells that transmit electrical signals from the brain to other parts of the body, and have recently been shown to play an active role in various behaviors and processes through a role much more subtle and difficult to measure known as calcium signaling. A previous WSU study showed that suppression of astrocyte calcium signaling throughout the brain caused mice to accumulate less need for sleep after sleep deprivation.
In this study, the researchers looked specifically at astrocytes in the basal forebrain, a region of the brain that plays a critical role in determining time spent asleep and awake, as well as the need for sleep. Using chemogenetics – a method of monitoring and studying signaling pathways within brain cells – they activated these astrocytes and found that this caused the mice to stay awake for six hours or more during their normal sleep period. Furthermore, the researchers did not observe subsequent changes in sleep time or intensity in response to the additional wakefulness, as expected.
“Our findings suggest that our need for sleep is not just a function of early waking time, but is also driven by these long-ignored non-neuronal cells,” said first author Ashley Ingiosi, an assistant professor. neuroscience at The Ohio State University. “We can now begin to identify how astrocytes interact with neurons to trigger this response, and how they drive the expression and regulation of sleep in different parts of the brain.”
The researchers’ next goal is to conduct behavioral tests in mice to determine how activation of basal forebrain astrocytes to induce wakefulness might affect processes other than the need for sleep, such as attention, cognition, learning, memory, metabolism and immune function. To get at least some indication of the potential impact on attention and cognition, they looked at the EEG markers of those two processes in this study and found that they were similar to those seen in well-rested controls.
