Secrets of the Spleen (broadcast Friday, July 25th, 2008)

The surface of the spleen. Gray's Anatomy, 1918.

What's a spleen good for? Once, it was thought that the five-ounce organ located in the upper left abdomen wasn't that important. Spleens or parts of spleens were regularly removed with little provocation. Now, there's an increasing understanding of the organ's importance as a part of the immune system, filtering blood and removing old blood cells. Writing this week in the Proceedings of the National Academy of Sciences, a team of investigators reports that the spleen and the brain may be more closely connected than previously thought. The splenic nerve, the researchers find, can communicate with the vagus nerve, which then serves as a conduit of information from the brain to the immune system. Manipulating the central nervous system may allow medical professionals to stimulate activity within the spleen, producing compounds needed to fight infection. We'll talk with one of the researchers on the project about the work, and what it means.