Asthma is the most common chronic condition among developing youth in the United States, however, little is known about how asthma-induced inflammation affects the brain. One of the major biological pathways that may be altered by allergic asthma is 5-hydroxytryptamine (5-HT) signaling. To test this hypothesis, I used an animal model to determine how experimentally induced asthma during development affects gene expression related to microglial activity and serotonin (5-HT) receptors.