Dr. Colton's research has centered on the study of chronic neurodegenerative diseases such as Alzheimer's disease. These diseases have a neuroinflammatory component involving the innate immune system in the CNS. Dr. Colton was among the first scientists to demonstrate that microglia are CNS macrophages and, like other tissue macrophages, respond to injury in the CNS by "killing" invading organisms. Microglia then help to orchestrate the "repair" process after injury. Recent research has focused on the regulation of microglial reactive oxygen species and reactive nitrogen species production as well as other cytoactive macrophage products that are made during the classical and alternative activation states associated with chronic neurodegeneration. Knowledge gained from the basic research program has been translated to the development of novel and extremely useful mouse models of Alzheimer's disease that enable pre-clinical testing of basic mechanisms and of potential therapeutics.