Serotonin Central

What am I looking at?

This image shows a 1.5-millimeter-thick coronal slice (from top to bottom) through the brain of a mouse, with neurons that produce serotonin (1 and 4) labeled in purple and pyramidal neurons (2) labeled in green. These clusters of serotonin-producing neurons (also known as serotonergic neurons) are located in an area of the brain called the raphe nucleus, just below the cerebral aqueduct (3), a fluid-filled canal in the midbrain.

Click on the right arrow to see an alternate view of this portion of a mouse’s brain; in this image, the serotonin-producing neurons are labeled orange.

Biology in the background

Serotonin is a biochemical compound that contributes to a variety of important biological functions, including the regulation of mood and emotions as well as of body temperature. Most of the neurons that produce serotonin originate in an area of the brain called the raphe nucleus. The serotonergic neurons in the raphe nucleus send projections throughout the brain and spinal cord to supply serotonin wherever it’s needed.

Two areas that the neurons in the raphe nucleus send serotonin to are the hypothalamus and the cerebral cortex, both of which also play significant roles in regulating mood and emotion.

In mice and humans alike, the cell bodies of serotonergic neurons can vary in size from 15 micrometers across, or roughly five times smaller than the width of a human hair, to 60 micrometers across, or slightly smaller than the width of a human hair.

Technique

These images were created using confocal microscopy.