Serotonin, also known as the happiness hormone, is a neurotransmitter that performs many important functions in the body, including regulating mood. In depression, antidepressants increase the amount of serotonin in the brain by stopping the clearance of serotonin. In addition, serotonin is suspected to play a role in early brain development in animals, including humans. But how does this work, and can using antidepressants disrupt this process?
At the University of Colorado, the effect of serotonin on the prefrontal cortex of mice was examined. The prefrontal cortex plays a central role in high-level cognitive functions and is therefore the focus of study. Since the third trimester of human pregnancy is biologically equivalent to the first two weeks of brain development in mice, the team focused on this specific stage of mouse pups’ development.
Synaptic changes
Research shows that serotonin is not only involved in general brain function, but also plays a specific role in influencing and changing communications between brain cells, which may affect learning and the brain’s ability to adapt. Fluoxetine administration led to changes in individual connections between brain cells in the prefrontal cortex.
Understanding this association has the potential to contribute to early intervention and the development of new therapeutic approaches for neurodevelopmental disorders involving serotonin dysregulation, such as autism or ADHD. In future experiments, researchers will test the long-term effects of increased serotonin exposure, either in normal mice or in a mouse model of autism.
“Fluoxetine not only crosses the placenta but also enters breast milk, leading to an increase in the amount of serotonin in the fetus,” said Won Chan Oh, one of the co-researchers. “However, it is important to emphasize that we cannot generalize our findings to brain development.” Humans: Pregnant women currently taking antidepressants should not simply stop taking them. More research will be needed to draw conclusions in humans.
