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Pressure to Sleep

Insight into the role of serotonin in promoting sleep

01 December 2019

Pressure to Sleep

The chemical serotonin travels through our body and helps regulate our mood – hence its label as a ‘happy’ hormone and its use in antidepressants. Serotonin is also involved in regulating our appetite, memories, and – importantly – sleep. But does serotonin put us to sleep or does it keep us awake? Scientists may have settled this debate by looking at the raphe nuclei, an area of the brain with the greatest number of serotonin-producing neurons (shown here in red in a zebrafish). By showing that zebrafish and mice without these cells don’t sleep as much or as normally as other animals, the team argue that the raphe nuclei may be releasing serotonin as the day goes on in order to build the animals’ pressure to sleep. Armed with this new knowledge, scientists may in future be able to find ways to manage the sleepy side effects of serotonin-based antidepressants.

Written by Gaëlle Coullon

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BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

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