Many people have experienced relief from depression after going without a good night’s sleep — but the mood boost typically only lasts until the person falls asleep again.
Although sleep deprivation is an impractical long term treatment, researchers have been interested in the workings behind this phenomenon. Now a research team at Tufts University has pinpointed glia as the key players.
Previously, the researchers found that astrocytes — a star-shaped type of glial cell — regulate the brain chemicals involved in sleepiness.
While we’re awake, astrocytes continuously release the neurotransmitter adenosine, which builds up in the brain and causes “sleep pressure,” the feeling of sleepiness and its related memory and attention deficits.
Adenosine creates this pressure by binding to receptors on the outside of neurons like a key fitting into a lock. As more adenosine builds up, more receptors are triggered, and the urge to sleep gets stronger.
In the new study, the researchers investigated whether this process is responsible for the antidepressant feelings during sleep deprivation. Mice with depressive-like symptoms were given three doses of a compound that triggers adenosine receptors — mimicking sleep deprivation.
Although the mice continued to sleep normally, after 12 hours they showed a significant improvement in mood and behavior, which lasted for 48 hours.
The findings verify that the buildup of adenosine is responsible for the antidepressant effects of a lack of sleep. These results lead to a promising target for new drug development because it suggests that mimicking sleep deprivation chemically may offer the antidepressant benefits without the unwanted side effects of actually losing sleep.
This type of treatment could give immediate relief from depression, especially compared to traditional antidepressants, which often take six to eight weeks to work.
According to Dustin Hines, lead author and a postdoctoral fellow at Tufts, this study may also have implications beyond depression and sleep regulation.
“For many years neuroscientists focused almost exclusively on neurons, whereas the role of glia was neglected,” Hines said.
“We now know that glia play an important role in the control of brain function and have the potential to aid in the development of new treatments for many illnesses, including depression and sleep disorders.”
Source: Translational Psychiatry