To facilitate mechanistic studies of AxD pathogenesis, and provide animal models suitable for testing potential therapies, we have generated knock-in lines of mice carrying the most common GFAP mutations found in human AxD (equivalent to R79H and R239H), and found that expression of mutant Gfap induces formation of Rosenthal fibers, increases susceptibility to kainate induced seizures [11], alters adult neurogenesis and leads to deficits in learning (T.L. Hagemann, et al., manuscript in preparation). Here, GFAP is linked to Alexander disease.