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

Gaëlle Coullon

Writer

Gaëlle is a consultant and trainer in research communication and commercialisation. As an ex-neuroscientist, she is always looking for new ways to combine her love of writing with everything brain related.

• Image from work by Grigorios Oikonomou and Michael Altermatt, and colleagues
• Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
• Image copyright Elsevier 2019. Reproduced with permission.
• Published in Neuron, June 2019