 oligodendrocytes and their progenitors are pregulate MHC pathways in response to inflammation, but the frequency of this phenotypic change is unknown and the features of these immune oligodendroglia are poorly defined. We generated MHC class 1 and 2 transgenic reporter mice to define their dynamics in response to inflammatory demyelination, providing a means to monitor MHC activation in diverse cell types in living mice and define their roles in aging, injury, and disease. This article was offered by M. P. Harrington, Riley B. Katanachi, Matthew D. Smith, and others.